Key Spec Table
|Safety Information according to GHS|
|Material Size||40 assays|
References | 63 Available | See All References
|Reference overview||Pub Med ID|
|Stem Cell Research & Therapy in 2012. |
Philippa Locke,Rocky S Tuan,Timothy O'Brien
Stem cell research & therapy 3 2012
|Impact of hepatic arterial reconstruction on orthotopic liver transplantation in the rat. |
Tomohide Hori,Lindsay B Gardner,Florence Chen,Ann-Marie T Baine,Toshiyuki Hata,Shinji Uemoto,Justin H Nguyen
Journal of investigative surgery : the official journal of the Academy of Surgical Research 25 2012
Orthotopic liver transplantation (OLT) models in rats have been investigated in many studies, but detailed information on the impact of hepatic artery (HA) reconstruction on postoperative factors remains to be investigated. HA reconstruction also requires advanced skills. The effect of the reconstruction of the HA by a hand-suture technique in rats with a whole-liver syngeneic graft was investigated. Long-term survival, histopathological assessment, immunohistological evaluation, and blood biochemistry were investigated until postoperative day (POD) 28. From the early postoperative period, significant differences between OLTs with or without HA reconstruction were found in graft parenchymal damage, induction of apoptosis, and transaminase levels, though survival curves and the coagulation profile showed no differences. In OLT without HA reconstruction, biliary proliferation was decreased at POD 5-14, and total bilirubin level was increased at PODs 10 and 14. The study indicates that HA reconstruction is required for reliable OLT in rats.
|Extract of white button mushroom affects skin healing and angiogenesis. |
W P Lam,C M Wang,T Y Tsui,M S Wai,H C Tang,Y W Wong,L H Lam,L K Hui,D T Yew
Microscopy research and technique 75 2012
White button mushroom extract was examined in this study on (1) its potential effect on angiogenesis in chorioallantoic culture and (2) its recovering effect on the skin after injury in the ICR mice. Methods used included TUNEL assay on apoptosis, immunohistochemistry for vascular endothelial growth factor (VEGF), proliferative cell nuclear antigen (PCNA), epidermal growth factor (EGF), transforming growth factor β (TGF-β), and immune factor CD4 and western blotting. The results of chorioallantoic culture showed that the mushroom treatment led to significant increase in densities of VEGF sites. In the skin injury, ICR mice model increased EGF, PCNA, and collagen fibers, along with decrease of TUNEL positive apoptotic cells and limited reaction of TGF-β and CD4 indicated that white button mushroom extract appeared to have beneficial effects on skin in regeneration and after injury. Microsc. Res. Tech. 2012.
|Hepatic arterial reconstruction for orthotopic liver transplantation in the rat. |
Tomohide Hori,Lindsay B Gardner,Feng Chen,Ann-Marie T Baine,Toshiyuki Hata,Aimee R Herdt,Shinji Uemoto,Christopher B Eckman,Justin H Nguyen
The Journal of surgical research 178 2012
Orthotopic liver transplantation (OLT) models in rats have been investigated in many studies. The reconstruction of hepatic artery is required for reliable OLT and also requires advanced skills.
|Hepatitis B virus alters the antioxidant system in transgenic mice and sensitizes hepatocytes to Fas signaling. |
Qian Wang,Bing Na,Jing-Hsiung James Ou,Lynn Pulliam,T S Benedict Yen
PloS one 7 2012
Hepatitis B virus (HBV) is a major etiological factor of hepatocellular carcinoma (HCC). However, the precise pathogenetic mechanisms linking HBV infection and HCC remain uncertain. It has been reported that decreased antioxidant enzyme activities are associated with severe liver injury and hepatocarcinogenesis in mouse models. It is unclear if HBV can interfere with the activities of antioxidant enzymes. We established a HBV transgenic mouse line, which spontaneously developed HCC at 2 years of age. We studied the activities of the antioxidant enzymes in the liver of the HBV transgenic mice. Our results showed that the antioxidant enzymes glutathione peroxidase and superoxide dismutase 2 were down-regulated in HBV transgenic mice and correlated with JNK activation. HBV enhanced the Fas-mediated activation of caspase 6, caspase 8 and JNK without enhancing the activation of caspase 3 and hepatocellular apoptosis. As a proper redox balance is important for maintaining cellular homeostasis, these effects of HBV on the host antioxidant system and Fas-signaling may play an important role in HBV-induced hepatocarcinogenesis.
|Nanoporous peptide particles for encapsulating and releasing neurotrophic factors in an animal model of neurodegeneration. |
Justin Tan,Yajun Wang,Xiaopei Yip,Fergal Glynn,Robert K Shepherd,Frank Caruso
Advanced materials (Deerfield Beach, Fla.) 24 2012
Neurotrophin-BDNF can be effectively encapsulated in nanoporous poly(L-glutamic acid) particles prepared via mesoporous silica templating. The loaded BDNF can be released in a sustained manner with retained biological activity. Animal experiments demonstrate the released BDNF can efficiently rescue the auditory neurons (as indicated by the arrows) in the cochlea of guinea pigs with sensorineural hearing loss.
|Uncoupling of PI3K from ErbB3 impairs mammary gland development but does not impact on ErbB2-induced mammary tumorigenesis. |
Hicham Lahlou,Thomas Müller,Virginie Sanguin-Gendreau,Carmen Birchmeier,William J Muller
Cancer research 72 2012
The formation of ErbB2/ErbB3 heterodimers plays a critical role in ErbB2-mediated signaling in both normal mammary development and mammary tumor progression. Through 7 phosphoinositide 3-kinase (PI3K) phosphotyrosine-binding sites, ErbB3 is able to recruit PI3K and initiate the PI3K/AKT signaling pathway. To directly explore the importance of the ErbB3/PI3K pathway in mammary development and tumorigenesis, we generated a mouse model that carries a mutant ErbB3 allele lacking the seven known PI3K-binding sites (ErbB3(Δ85)). Mice homozygous for the ErbB3(Δ85) allele exhibited an initial early growth defect and a dramatic impairment of mammary epithelial outgrowth. Although homozygous adult mice eventually recovered from the growth defect, their mammary glands continued to manifest the mammary outgrowth and lactation defects throughout their adult life. Interestingly, despite the presence of a profound mammary gland defect, all of the female ErbB3Δ85 mice developed metastatic ErbB2-induced mammary tumors secondary to mammary epithelial expression of an activated ErbB2 oncogene capable of compensatory PI3K signaling from both EGF receptor and ErbB2. Our findings therefore indicate that, although ErbB3-associated PI3K activity is critical for mammary development, it is dispensable for ErbB2-induced mammary tumor progression.
|Osteocyte network; a negative regulatory system for bone mass augmented by the induction of rankl in osteoblasts and sost in osteocytes at unloading. |
Takeshi Moriishi,Ryo Fukuyama,Masako Ito,Toshihiro Miyazaki,Takafumi Maeno,Yosuke Kawai,Hisato Komori,Toshihisa Komori
PloS one 7 2012
Reduced mechanical stress is a major cause of osteoporosis in the elderly, and the osteocyte network, which comprises a communication system through processes and canaliculi throughout bone, is thought to be a mechanosensor and mechanotransduction system; however, the functions of osteocytes are still controversial and remain to be clarified. Unexpectedly, we found that overexpression of BCL2 in osteoblasts eventually caused osteocyte apoptosis. Osteoblast and osteoclast differentiation were unaffected by BCL2 transgene in vitro. However, the cortical bone mass increased due to enhanced osteoblast function and suppressed osteoclastogenesis at 4 months of age, when the frequency of TUNEL-positive lacunae reached 75%. In the unloaded condition, the trabecular bone mass decreased in both wild-type and BCL2 transgenic mice at 6 weeks of age, while it decreased due to impaired osteoblast function and enhanced osteoclastogenesis in wild-type mice but not in BCL2 transgenic mice at 4 months of age. Rankl and Opg were highly expressed in osteocytes, but Rankl expression in osteoblasts but not in osteocytes was increased at unloading in wild-type mice but not in BCL2 transgenic mice at 4 months of age. Sost was locally induced at unloading in wild-type mice but not in BCL2 transgenic mice, and the dissemination of Sost was severely interrupted in BCL2 transgenic mice, showing the severely impaired osteocyte network. These findings indicate that the osteocyte network is required for the upregulation of Rankl in osteoblasts and Sost in osteocytes in the unloaded condition. These findings suggest that the osteocyte network negatively regulate bone mass by inhibiting osteoblast function and activating osteoclastogenesis, and these functions are augmented in the unloaded condition at least partly through the upregulation of Rankl expression in osteoblasts and that of Sost in osteocytes, although it cannot be excluded that low BCL2 transgene expression in osteoblasts contributed to the enhanced osteoblast function.
|Reduced intestinal tumorigenesis in APCmin mice lacking melanin-concentrating hormone. |
Jutta M Nagel,Brenda M Geiger,Apostolos K A Karagiannis,Beatriz Gras-Miralles,David Horst,Robert M Najarian,Dimitrios C Ziogas,Xinhua Chen,Efi Kokkotou
PloS one 7 2012
Melanin-concentrating hormone (MCH) is an evolutionary conserved hypothalamic neuropeptide that in mammals primarily regulates appetite and energy balance. We have recently identified a novel role for MCH in intestinal inflammation by demonstrating attenuated experimental colitis in MCH deficient mice or wild type mice treated with an anti-MCH antibody. Therefore, targeting MCH has been proposed for the treatment of inflammatory bowel disease. Given the link between chronic intestinal inflammation and colorectal cancer, in the present study we sought to investigate whether blocking MCH might have effects on intestinal tumorigenesis that are independent of inflammation.
|Pten deletion causes mTorc1-dependent ectopic neuroblast differentiation without causing uniform migration defects. |
Guo Zhu,Lionel M L Chow,Ildar T Bayazitov,Yiai Tong,Richard J Gilbertson,Stanislav S Zakharenko,David J Solecki,Suzanne J Baker
Development (Cambridge, England) 139 2012
Neuronal precursors, generated throughout life in the subventricular zone, migrate through the rostral migratory stream to the olfactory bulb where they differentiate into interneurons. We found that the PI3K-Akt-mTorc1 pathway is selectively inactivated in migrating neuroblasts in the subventricular zone and rostral migratory stream, and activated when these cells reach the olfactory bulb. Postnatal deletion of Pten caused aberrant activation of the PI3K-Akt-mTorc1 pathway and an enlarged subventricular zone and rostral migratory stream. This expansion was caused by premature termination of migration and differentiation of neuroblasts and was rescued by inhibition of mTorc1. This phenotype is reminiscent of lamination defects caused by Pten deletion in developing brain that were previously described as defective migration. However, live imaging in acute slices showed that Pten deletion did not cause a uniform defect in the mechanics of directional neuroblast migration. Instead, a subpopulation of Pten-null neuroblasts showed minimal movement and altered morphology associated with differentiation, whereas the remainder showed unimpeded directional migration towards the olfactory bulb. Therefore, migration defects of Pten-null neurons might be secondary to ectopic differentiation.
|Periostin is Down-regulated during Periodontal Inflammation. |
M Padial-Molina,S L Volk,A D Taut,W V Giannobile,H F Rios
Journal of dental research 91 2012
Periostin, a matricellular adapter protein highly expressed by periodontal ligament fibroblasts, is implicated in the maintenance of periodontal integrity, which is compromised during periodontal diseases. The aim of this study was to explore the influence of chronic periodontal inflammation on tissue periostin levels. Periodontal breakdown was induced in a pre-clinical ligature periodontal inflammatory disease model. Periodontal tissue specimens were harvested at baseline, 2 weeks, and 4 weeks and prepared for histologic, immunofluorescence, and micro-CT examination. Statistical analyses were conducted by Kruskal-Wallis, Mann-Whitney, and Spearman's tests. Periostin detection levels were reduced over time in response to the inflammatory process (1 ± 0.05; 0.67 ± 0.03; 0.31 ± 0.02; p < 0.001; baseline, 2, and 4 weeks, respectively). Simultaneously, alveolar bone loss increased from baseline to the 2- and 4-week time-points (0.40 ± 0.02 mm; 1.39 ± 0.08 mm; 1.33 ± 0.15 mm; p < 0.001), which was inversely correlated with the levels of periostin (ρ = -0.545; p < 0.001). In conclusion, periostin PDL tissue levels significantly decrease under chronic inflammatory response and correlate with the detrimental changes to the periodontium over time.
|Thrombin-sensitive dual fluorescence imaging and therapeutic agent for detection and treatment of synovial inflammation in murine rheumatoid arthritis. |
Doris Gabriel,Norbert Lange,Veronique Chobaz-Peclat,Maria Fernanda Zuluaga,Robert Gurny,Hubert van den Bergh,Nathalie Busso
Journal of controlled release : official journal of the Controlled Release Society 163 2012
We have developed a thrombin-sensitive polymeric photosensitizer prodrug (T-PS) to selectively image and eradicate inflammatory lesions in rheumatoid arthritis (RA). Thrombin is a serine protease up-regulated in synovial tissues of rheumatoid arthritis (RA) patients. T-PS consists of a polymeric backbone, to which multiple photosensitizer (PS) units are tethered via short thrombin-cleavable peptide linkers. Fluorescence emission and phototoxicity of the prodrug are efficiently quenched due to the interaction of neighboring photosensitizer units. The prodrug is passively delivered to the inflammation site via the enhanced permeability and retention (EPR) effect. Subsequent site-selective proteolytic cleavage of the peptide linkers restores its photoactivity by increasing the mutual distance between PS. Whole animal imaging in murine collagen-induced arthritis, an experimental model of RA revealed a dose-dependent fluorescence increase in arthritic paws after systemic prodrug injection. In addition, administration of T-PS resulted in much higher fluorescence selectivity for arthritic joints as compared to the free PS. Irradiation of the arthritic joints induced light dose dependent phototoxic effects such as apoptosis, vascular damage and local hemorrhage. Long-term observations showed complete regression of the latter. Irradiated non-arthritic tissues or non-irradiated arthritic tissues showed no histological effects after photodynamic therapy with T-PS. This illustrates that T-PS can localize inflammatory lesions with excellent selectivity and induce apoptosis and vascular shut down after irradiation.
|Knockdown of clusterin sensitizes pancreatic cancer cells to gemcitabine chemotherapy by ERK1/2 inactivation. |
Yong Tang,Fenghua Liu,Chunning Zheng,Shaochuan Sun,Yingsheng Jiang
Journal of experimental & clinical cancer research : CR 31 2012
|Severity of doxorubicin-induced small intestinal mucositis is regulated by the TLR-2 and TLR-9 pathways. |
Agnieszka Kaczmarek,Brigitta M Brinkman,Liesbeth Heyndrickx,Peter Vandenabeele,Dmitri V Krysko
The Journal of pathology 226 2012
Intestinal mucositis is a serious complication of cancer chemotherapy and radiotherapy; it frequently compromises treatment and dramatically reduces the quality of life of patients. Different approaches to limit the damage to the intestine during anti-cancer therapy have been largely ineffective due to insufficient knowledge of the mechanism of mucositis development. This study aimed to define the role of TLR-2 and TLR-9 in the modulation of small intestinal damage in a model of doxorubicin-induced mucositis. Doxorubicin-induced intestinal damage was verified by a histological score (HS), analysis of leukocyte influx into the lamina propria, and determination of the number of apoptotic cells. Additionally, the activation status of glycogen synthase kinase 3? (GSK-3?) was assessed. Wild-type (WT) mice injected with doxorubicin demonstrated severe intestinal damage (HS 8.0 ± 0.81), reduction of villus length to 43.9% ± 13.7% of original length, and increased influx of leukocytes as compared to vehicle-injected mice (HS 1.33 ± 1.15). The protective effect of TLR-2 or TLR-9 deficiency was associated with a significant decrease of the HS as compared to WT mice. In the ileum, a minor reduction of villus length and a decreased number of infiltrating leukocytes and TUNEL-positive cells was observed. We demonstrate that the TLR-9 antagonist ODN2088 reduces doxorubicin-induced intestinal damage. Furthermore, we show that GSK-3? activity is inhibited in the absence of TLR-2. The protective capacity of GSK-3? suppression was observed in WT mice by inhibiting it with the specific inhibitor SB216763. Overall, our findings demonstrate that the TLR-2/GSK-3? and TLR-9 signalling pathways play a central role in the development of intestinal mucositis and we suggest a new therapeutic strategy for limiting doxorubicin-induced intestinal inflammation. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
|Subacute oral toxicity investigation of nanoparticulate and ionic silver in rats. |
Niels Hadrup,Katrin Loeschner,Anders Bergström,Andrea Wilcks,Xueyun Gao,Ulla Vogel,Henrik L Frandsen,Erik H Larsen,Henrik R Lam,Alicja Mortensen
Archives of toxicology 86 2012
Subacute toxicity of 14 nm nanoparticulate silver (Ag-NP) stabilised with polyvinylpyrrolidone and ionic silver in the form of silver acetate (Ag-acetate) was investigated in four-week-old Wistar rats. Animals received orally by gavage the following: vehicle control (10 ♀, 6 ♂); Ag-NP at doses: 2.25 (8 ♀), 4.5 (8 ♀) or 9 mg/kg bw/day (10 ♀, 6 ♂); or Ag-acetate 9 mg silver/kg bw/day (8 ♀) for 28 days. Clinical, haematolological and biochemical parameters, organ weights, macro- and microscopic pathological changes were investigated. Caecal bacterial phyla and their silver resistance genes were quantified. For the Ag-NP groups, no toxicological effects were recorded. For Ag-acetate, lower body weight gain (day 4-7, 11-14, 14-16, P < 0.05; overall, day 1-28, P < 0.01), increased plasma alkaline phosphatase (P < 0.05), decreased plasma urea (P < 0.05) and lower absolute (P < 0.01) and relative (P < 0.05) thymus weight were recorded. In conclusion, these findings indicate toxicity of 9 mg/kg bw/day ionic silver but not of an equimolar Ag-NP dose. This is in accordance with previously reported data showing that oral Ag-acetate, in comparison with an equimolar dose of Ag-NP, resulted in higher silver plasma and organ concentrations.
|Molecular mechanism of remodeling of autologous artery graft interposed to vein in rabbit. |
Yanling Feng,Yanguo Shen,Hongqi Zhang
Anatomical record (Hoboken, N.J. : 2007) 295 2012
Our previous study found that the artery interposed to vein did not develop atherosclerosis but rather underwent atrophic remodeling in hyperlipidemic rabbits, suggesting that local hemodynamic load was another important determinant for the development of atherosclerosis. This study focused on the cellular and molecular changes in autologous artery grafts derived from rabbits fed with high lipid diet for 1, 2, 4, 8, and 12 weeks. Thickness, area of vessel wall, and lumen area were measured and analyzed on the grafted common carotid artery (GCCA) interposed to vein and on the right common carotid artery. Apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labeling. Both elastin and collagen of GCCA were identified by the method of double stains of elastin and collagen. Reverse transcription polymerase chain reaction was used to observe matrix metalloproteinases (MMPs) mRNA expression changes in the examined arteries. The lumen area increased gradually in control common carotid artery and remained unchanged in GCCA 3 months later, since the surgery and the start of high lipid diet, while significantly increased apoptosis was evidenced from inner to outer part of GCCA. Collagen content decreased gradually and elastic fibers remained unchanged in GCCA. At 1 week after operation, the mRNA expression of MMP(2) and MMP(9) increased significantly and returned to baseline thereafter. The artery interposed to a vein underwent atrophy, characterized by increased apoptosis in the vessel wall from intima to adventitia, possibly due to low shear stress circumference and reduced vessel collagen resulting from postsurgical upregulated MMP(2) and MMP(9) expression.
|Serine/threonine phosphatase (SP-STP), secreted from Streptococcus pyogenes, is a pro-apoptotic protein. |
Shivani Agarwal,Shivangi Agarwal,Hong Jin,Preeti Pancholi,Vijay Pancholi
The Journal of biological chemistry 287 2012
This investigation illustrates an important property of eukaryote-type serine/threonine phosphatase (SP-STP) of group A Streptococcus (GAS) in causing programmed cell death of human pharyngeal cells. The secretory nature of SP-STP, its elevated expression in the intracellular GAS, and the ability of wild-type GAS but not the GAS mutant devoid of SP-STP to cause apoptosis of the host cell both in vitro and in vivo suggest that GAS deploys SP-STP as an important virulence determinant to exploit host cell machinery for its own advantage during infection. The exogenously added SP-STP is able to enter the cytoplasm and subsequently traverses into the nucleus in a temporal fashion to cause apoptosis of the pharyngeal cells. The programmed cell death induced by SP-STP, which requires active transcription and de novo protein synthesis, is also caspase-dependent. Furthermore, the entry of SP-STP into the cytoplasm is dependent on its secondary structure as the catalytically inactive SP-STP with an altered structure is unable to internalize and cause apoptosis. The ectopically expressed wild-type SP-STP was found to be in the nucleus and conferred apoptosis of Detroit 562 pharyngeal cells. However, the catalytically inactive SP-STP was unable to cause apoptosis even when intracellularly expressed. The ability of SP-STP to activate pro-apoptotic signaling cascades both in the cytoplasm and in the nucleus resulted in mitochondrial dysfunctioning and perturbation in the phosphorylation status of histones in the nucleus. SP-STP thus not only functions as a virulence regulator but also as an important factor responsible for host-related pathogenesis.
|Splenocyte apoptosis and autophagy is mediated by interferon regulatory factor 1 during murine endotoxemia. |
Lemeng Zhang,Jon S Cardinal,Pinhua Pan,Brian R Rosborough,Ying Chang,Wei Yan,Hai Huang,Timothy R Billiar,Matthew R Rosengart,Allan Tsung
Shock (Augusta, Ga.) 37 2012
Sepsis-induced lymphocyte and dendritic cell apoptosis contributes to immunosuppression, which results in an inability to eradicate the primary infection as well as a propensity to acquire new, secondary infections. Another cellular process, autophagy, is also activated in immune cells and plays a protective role. In the present study, we demonstrate that interferon regulatory factor 1 (IRF-1) regulates both immune cell apoptosis and autophagy in a murine endotoxemia model. Interferon regulatory factor 1 is activated at an early phase through a Toll-like receptor 4-dependent, myeloid differentiation primary response gene 88-independent manner in splenocytes. Furthermore, IRF-1 knockout (KO) mice are protected from a lethal endotoxemia model. This protection is associated with decreased apoptosis and increased autophagy in splenocytes. Interferon regulatory factor 1 KO mice experience decreased apoptotic cell loss, especially in CD4⁺ T lymphocytes and myeloid antigen-presenting cells. Meanwhile, IRF-1 KO mice demonstrate increased autophagy and improved mitochondrial integrity. This increased autophagy in KO mice is attributable, at least in part, to deactivation of mammalian target of rapamycin/P70S6 signaling--a main negative regulator of autophagy. Therefore, we propose a novel role for IRF-1 in regulating both apoptosis and autophagy in splenocytes in the setting of endotoxemia with IRF-1 promoting apoptosis and inhibiting autophagy.
|Pretreatment of Cisplatin in recipients attenuates post-transplantation pancreatitis in murine model. |
Sheng Yan,Yuan Ding,Fei Sun,Zhongjie Lu,Liang Xue,Xiangyan Liu,Mingqi Shuai,Chen Fang,Yan Wang,Hui Cheng,Lin Zhou,Ming H Zheng,Shusen Zheng
International journal of biological sciences 8 2012
Pancreas transplantation is the definite treatment for type 1 diabetes that enables the achievement of long-term normoglycemia and insulin independence. However Post-Transplantation Pancreatitis (PTP) due to ischemia reperfusion (IR) injury and preservation is a major complication in pancreas transplantation. Owning the potential anti-inflammatory effect of Cisplatin (Cis) in liver IR injury, we have examined if Cis could attenuate PTP using a murine model. We found that Cis is able to prevent inflammatory response in PTP. Pretreatment of Cis in recipient mice reduce the impairments of the grafts and hyperamylasimea in the recipients. We documented that the protective mechanism of Cis in PTP involves improvement of microcirculation, reduction of the mononuclear cellular infiltration and apoptosis, suppression of inflammatory cytokine-cascade and inhibition of translocation of high-motility group box protein-1 (HMGB-1) from nucleus to cytoplasm. In short, our study demonstrated that pretreatment of Cis in recipients may reduce the onset of PTP in pancreas transplantation.
|Developmental exposure to manganese chloride induces sustained aberration of neurogenesis in the hippocampal dentate gyrus of mice. |
Liyun Wang,Takumi Ohishi,Ayako Shiraki,Reiko Morita,Hirotoshi Akane,Yoshiaki Ikarashi,Kunitoshi Mitsumori,Makoto Shibutani
Toxicological sciences : an official journal of the Society of Toxicology 127 2012
The effect of exogenously administered manganese (Mn) on developmental neurogenesis in the hippocampal dentate gyrus was examined in male mice after maternal exposure to MnCl(2) (0, 32, 160, or 800 ppm as Mn in diet) from gestational day 10 to day 21 after delivery on weaning. Immunohistochemistry was performed to monitor neurogenesis and interneuron subpopulations on postnatal days (PNDs) 21 and 77 (adult stage). Reelin-synthesizing γ-aminobutyric acid (GABA)ergic interneurons increased in the hilus with ≥ 160 ppm on weaning to sustain to PND 77 at 800 ppm. Apoptosis in the neuroblast-producing subgranular zone increased with 800 ppm and TUC4-expressing immature granule cells decreased with 800 ppm on weaning, whereas at the adult stage, immature granule cells increased. On PND 21, transcript levels increased with Reln and its receptor gene Lrp8 and decreased with Dpysl3 coding TUC4 in the dentate gyrus, confirming immunohistochemical results. Double immunohistochemistry revealed a sustained increase of reelin-expressing and NeuN-lacking or weakly positive immature interneurons and NeuN-expressing mature neurons in the hilus through to the adult stage as examined at 800 ppm. Brain Mn concentrations increased at both PNDs 21 and 77 in all MnCl(2)-exposed groups. These results suggest that Mn targets immature granule cells causing apoptosis and neuronal mismigration. Sustained increases in immature reelin-synthesizing GABAergic interneurons may represent continued aberration in neurogenesis and following migration to cause an excessive response for overproduction of immature granule cells through to the adult stage. Sustained high concentration of Mn in the brain may be responsible for these changes.
|Drug response in a genetically engineered mouse model of multiple myeloma is predictive of clinical efficacy. |
Marta Chesi,Geoffrey M Matthews,Victoria M Garbitt,Stephen E Palmer,Jake Shortt,Marcus Lefebure,A Keith Stewart,Ricky W Johnstone,P Leif Bergsagel
Blood 120 2012
The attrition rate for anticancer drugs entering clinical trials is unacceptably high. For multiple myeloma (MM), we postulate that this is because of preclinical models that overemphasize the antiproliferative activity of drugs, and clinical trials performed in refractory end-stage patients. We validate the Vk*MYC transgenic mouse as a faithful model to predict single-agent drug activity in MM with a positive predictive value of 67% (4 of 6) for clinical activity, and a negative predictive value of 86% (6 of 7) for clinical inactivity. We identify 4 novel agents that should be prioritized for evaluation in clinical trials. Transplantation of Vk*MYC tumor cells into congenic mice selected for a more aggressive disease that models end-stage drug-resistant MM and responds only to combinations of drugs with single-agent activity in untreated Vk*MYC MM. We predict that combinations of standard agents, histone deacetylase inhibitors, bromodomain inhibitors, and hypoxia-activated prodrugs will demonstrate efficacy in the treatment of relapsed MM.
|In vivo efficacy of the histone deacetylase inhibitor suberoylanilide hydroxamic acid in combination with radiotherapy in a malignant rhabdoid tumor mouse model. |
Markus Thiemann,Susanne Oertel,Volker Ehemann,Wilko Weichert,Albrecht Stenzinger,Marc Bischof,Klaus-J Weber,Ramon Lopez Perez,Uwe Haberkorn,Andreas E Kulozik,Jürgen Debus,Peter E Huber,Claudia Battmann
Radiation oncology (London, England) 7 2012
Histone deacetylase inhibitors are promising new substances in cancer therapy and have also been shown to sensitize different tumor cells to irradiation (XRT). We explored the effect as well as the radiosensitizing properties of suberoylanilide hydroxamic acid (SAHA) in vivo in a malignant rhabdoid tumor (MRT) mouse model.
|Slug regulates proliferation and invasiveness of esophageal adenocarcinoma cells in vitro and in vivo. |
Kejun Zhang,Shaoyan Zhang,Xuelong Jiao,Haibo Wang,Dianliang Zhang,Zhaojian Niu,Yi Shen,Liang Lv,Yanbing Zhou
Medical oncology (Northwood, London, England) 28 2011
Slug is a transcription factor and E-cadherin repressor, which has recently been demonstrated to be important for cancer cells to down-regulate epithelial markers and up-regulate mesenchymal markers in order to become motile and invasive. In the present study, we assessed the relevance of Slug for invasion and growth potential of esophageal adenocarcinoma (EA) cells in vitro and in vivo. Slug expression was detected in nine human esophageal cancer cell lines. OE33 cell line was infected with Slug siRNA to knockdown of Slug; TE7 cell line was infected with full Slug cDNA to increase Slug expression. Then, Bcl-2 and E-cadherin expression and Caspase-3 activity were analyzed. MTT assay was applied to detect growth curve. The flow cytometric and Hoechst33258 staining was performed to detect apoptosis. The cells invasion in vitro was detected with a Boyden chamber. A pseudometastatic model of OE33 and TE7 in immunodeficient mice was used to assess the effects of knockdown of Slug and Slug overexpression on metastasis development. A subcutaneously nude mice xenograft model of OE33 and TE7 was used to assess the effects of knockdown of Slug and Slug overexpression on tumor growth. Immunohistochemical staining was used to analyze the expression of Slug, bcl-2 and E-cadherin, and TUNEL was used to detected apoptosis in vivo. Western blotting and RT-PCR showed that Slug expression was detectable in 7 of 9 human esophageal cancer cell lines. Bcl-2 was down-regulated and E-cadherin was up-regulated significantly in Slug siRNA-infected OE33 cell line (P<0.01). Bcl-2 was upregulated and E-cadherin was downregulated significantly in Slug cDNA-infected TE7 cells (P<0.05). OE33 cells with Slug knockdown were shown to possess markedly decreased invasiveness (P<0.05) and markedly increased apoptosis (P<0.05). Slug cDNA-infected TE7 cells were shown only to possess markedly increased invasiveness (P<0.05). There was significant relationship between Slug knockdown or Slug overexpression and cells proliferation (respectively, P<0.05). Animals injected with Slug-silenced OE33 cells had fewer seeded tumor (P<0.01), more apoptosis cells (P<0.05) and significantly xenograft tumor growth regression (P<0.05). But in Slug cDNA-infected TE7 cells, more seeded tumor number and significantly xenograft tumor growth were found in xenograft tumor (respectively, P<0.05). It was showed in the subcutaneously nude mice xenograft model tumor tissue, bcl-2 expression was reduced followed by the decrease of Slug expression in Slug-silenced tumor, and bcl-2 expression was increased followed by the increase of Slug expression. In pseudometastatic model, E-cadherin overexpression was found in Slug siRNA tumor tissue, but less E-cadherin expression was found in Slug cDNA tissue. Slug is an important modulator of apoptosis, growth and invasion in EA in vitro and in vivo. Slug inhibition may represent a novel strategy for treatment of EA.
|JNK stress-activated protein kinase associated protein 1 is required for early development of telencephalic commissures in embryonic brains. |
Cho IH, Lee KW, Ha HY, Han PL
Experimental & molecular medicine 43 462-70. 2011
We previously reported that mice lacking JSAP1 (jsap1-/-) were lethal and the brain of jsap1-/- at E18.5 exhibited multiple types of developmental defects, which included impaired axon projection of the corpus callosum and anterior commissures. In the current study, we examined whether the early telencephalic commissures were formed abnormally from the beginning of initial development or whether they arose normally, but have been progressively lost their maintenance in the absence of JSAP1. The early corpus callosum in the brain of jsap1+/+ at E15.5-E16.5 was found to cross the midline with forming a distinct U-shaped tract, whereas the early axonal tract in jsap1-/- appeared to cross the midline in a diffuse manner, but the lately arriving axons did not cross the midline. In the brain of jsap1-/- at E17.5, the axon terminals of lately arriving collaterals remained within each hemisphere, forming an early Probst\'s bundle-like shape. The early anterior commissure in the brain of jsap1+/+ at E14.5-E15.5 crossed the midline, whereas the anterior commissure in jsap1-/- developed, but was deviated from their normal path before approaching the midline. The axon tracts of the corpus callosum and anterior commissure in the brain of jsap1-/- at E16.5-E17.5 expressed phosphorylated forms of FAK and JNK, however, their expression levels in the axonal tracts were reduced compared to the respective controls in jsap1+/+. Considering the known scaffolding function of JSAP1 for the FAK and JNK pathways, these results suggest that JSAP1 is required for the pathfinding of the developing telencephalic commissures in the early brains.Full Text Article
|Viral genome dNAlipoplexes elicit in situ oncolytic viral replication and potent antitumor efficacy via systemic delivery. |
Kwon OJ, Kang E, Kim S, Yun CO
Journal of controlled release : official journal of the Controlled Release Society 2011
Modifying the viral genome to express potent and cancer-selective therapeutic genes has enhanced the role of adenoviruses (Ads) in cancer molecular therapeutics. However, the efficacy of Ad systemic delivery in vivo is limited by neutralizing antibodies, short blood circulation time, and high levels of nonspecific liver uptake resulting in hepatotoxicity. We therefore investigated the systemic delivery of tumor necrosis factor-related apoptosis-inducing ligand-expressing oncolytic Ad genome DNA (pmT-d19/stTR) via lipid envelopment as an alternative approach for cancer virotherapy in an orthotopic lung cancer model. Cationic liposomes (DOTAP/DOPE) were complexed with pmT-d19/stTR to generate pmT-d19/stTR+DOTAP/DOPE with the average diameter of which was 143.3±5.7nm at the optimal DNA:lipid ratio (1:6). Systemic administration of pmT-d19/stTR+DOTAP/DOPE elicited highly effective antitumor responses in vivo, with tumor volumes decreasing 94.5%, 90.5%, and 92.4% compared to phosphate buffered saline-, naked Ad (mT-d19/stTR)-, or pmT-d19/stTR-treated groups, respectively. Additionally, innate immune responses and Ad-specific neutralizing antibodies were significantly decreased in pmT-d19/stTR+DOTAP/DOPE-treated mice compared to those in the mT-d19/stTR-treated group. The biodistribution profile analyzed by quantitative-PCR and immunohistochemical analysis demonstrated that viral replication occurred preferentially in tumor tissues. Moreover, the viral genome tumor-to-liver ratio was significantly elevated in pmT-d19/stTR+DOTAP/DOPE-treated mice, which was 934- and 27-fold greater than the mT-d19/stTR- and pmT-d19/stTR-treated mice, respectively. These results demonstrate that systemic delivery of oncolytic viral genome DNA with liposomes is a powerful alternative to naked Ad, overcoming the limited clinical applicability of conventional Ads and enabling effective treatment of disseminated metastatic tumors.Copyright © 2011. Published by Elsevier B.V.
|K252a suppresses neuronal cells apoptosis through inhibiting the translocation of bax to Mitochondria induced by the MLK3JNK signaling after transient global brain ischemia in rat hippocampal CA1 subregion. |
Wang Q, Yin XH, Liu Y, Zhang GY
Journal of receptor and signal transduction research 31 307-13. Epub 2011 Jul 5. 2011
It is demonstrated that the c-Jun N-terminal kinase (JNK) signaling pathway plays a critical role in ischemic brain injury. Our previous studies have suggested that K252a can obviously inhibit JNK activation induced by ischemia/reperfusion in the vulnerable hippocampal CA1 subregion. Here, we further discussed the potential mechanism of ischemic brain injury induced by the activation of JNK after 15?min of transient global cerebral ischemia. As a result, through inhibiting phosphorylation of Bcl-2 (a cytosolic target of JNK) and 14-3-3 protein (a cytoplasmic anchor of Bax) induced by the activation of JNK, K252a decreased the release of Bax from Bcl-2/Bax and 14-3-3/Bax dimers, further attenuating the translocation of Bax from cytosol to mitochondria and the release of cytochrome c induced by ischemia/reperfusion, which related to mitochondria-mediated apoptosis. Importantly, pre-infusion of K2525a 20?min before ischemia showed neuroprotective effect against neuronal cells apoptosis. These findings imply that K252a induced neuroprotection against ischemia/reperfusion in rat hippocampal CA1 subregion via inhibiting the mitochondrial apoptosis pathway induced by JNK activation.
|Humanin preserves endothelial function and prevents atherosclerotic plaque progression in hypercholesterolemic apoE deficient Mice. |
Oh YK, Bachar AR, Zacharias DG, Kim SG, Wan J, Cobb LJ, Lerman LO, Cohen P, Lerman A
|Glucagon-Like Peptide-1 Receptor Activation Inhibits Growth and Augments Apoptosis in Murine CT26 Colon Cancer Cells. |
Koehler JA, Kain T, Drucker DJ
Endocrinology 152 3362-72. Epub 2011 Jul 19. 2011
Obesity, accompanying or independent of type 2 diabetes mellitus (T2DM), is associated with higher rates of malignancy. Hence, there is considerable interest in understanding whether therapies used to treat obese patients with T2DM impact cancer cell growth. Glucagon-like peptide-1 (GLP-1) is produced in enteroendocrine cells and secreted after meal ingestion. GLP-1 regulates blood glucose through multiple mechanisms, principally inhibition of glucagon and stimulation of insulin secretion. GLP-1 also exerts independent effects promoting cell growth and survival, and sustained activation of GLP-1 receptor (GLP-1R) signaling in rodent thyroid glands leads to C-cell hyperplasia and medullary thyroid cancer. Hence, whether therapies based on GLP-1R activation modify growth or survival of cancer cells is of ongoing interest. We studied the biological actions of GLP-1 in mouse CT26 colon cancer cells that express a functional GLP-1R. The GLP-1R agonist exendin (Ex)-4 (exenatide) increased intracellular cAMP levels and inhibited the activity of signaling kinases glycogen synthase kinase 3 and ERK1/2 in CT26 cells. The Ex-4-induced inactivation of glycogen synthase kinase 3, but not ERK1/2, was dependent on protein kinase A and blocked by the GLP-1R antagonist Ex(9-39). Furthermore, Ex-4 altered cell morphology, induced apoptosis, and inhibited proliferation of CT26 cells in vitro. Moreover Ex-4 decreased CT26 colony formation in soft agar and augmented apoptosis induced by irinotecan. Twice-daily treatment of CT26 tumor-bearing BALB/c mice with Ex-4 for 2 wk increased tumor apoptosis. Hence, GLP-1R activation reduces growth and survival in CT26 colon cancer cells that express the endogenous classical GLP-1R.
|Fibroblast growth factor-2-overexpressing myoblasts encapsulated in alginate spheres increase proliferation, reduce apoptosis, induce adipogenesis, and enhance regeneration following skeletal muscle injury in rats. |
Stratos I, Madry H, Rotter R, Weimer A, Graff J, Cucchiarini M, Mittlmeier T, Vollmar B
Tissue engineering Part A 17 2867-77. Epub 2011 Aug 4. 2011
The fibroblast growth factor 2 (FGF-2) is known as pleiotropic cytokine with myoblast proliferative properties. In the present study, we tested the hypothesis that gene transfer of human FGF-2 via transplantation of genetically modified L8-myoblast encapsulated in alginate modulates the skeletal muscle recovery after crush injury in Wistar rats. Therefore, we performed a crush injury to the soleus muscle and transplanted alginate spheres containing myoblasts genetically modified to overexpress human FGF-2 (FGF-2) or a luciferase (LUC) cDNA at the site of injury. Animals that underwent muscle injury without transplantation of alginate spheres served as control (control). At day 4 after trauma the FGF-2 group showed significant higher mean values of cell proliferation (bromodeoxyuridine immunohistochemistry) and significant lower values of cell apoptosis (terminal deoxynucleotidyl transferase nick end labeling histology) compared to animals receiving luciferase-overexpressing myoblasts. At the same time point adiponectin expression (ACRP30 immunohistochemistry) was increased in the FGF-2 group exclusively. The p75(NTR) expression (p75(NTR) immunohistochemistry) significantly improved in both the FGF-2 and LUC group compared to the control group. Functional analysis of the injured muscle did not reveal a significant increase of the muscle force in the FGF-2 group compared to the control and LUC group 14 days after injury. In vitro analysis for 14 days of the FGF-2-modified spheres demonstrated at day 7 and day 14 a significant increase of the relative cell count as well as of the relative viable cell count in the FGF-2 myoblast spheres compared to luciferase myoblast spheres. Additionally, the expression of FGF-2 (enzyme-linked immunosorbent assay analysis) and luciferase (chemiluminescence analysis) persisted in vitro for 4 and 14 days, respectively. These results demonstrate that FGF-2-overexpressing myoblasts cannot considerably improve muscle strength but are able to modulate the proliferation as well as the apoptosis of injured muscle tissue mainly by conducting adipogenesis.
|NP body domain and PB2 contribute to increased virulence of H5N1 highly pathogenic avian influenza viruses in chickens. |
Tada T, Suzuki K, Sakurai Y, Kubo M, Okada H, Itoh T, Tsukamoto K
J Virol 85 1834-46. Epub 2010 Dec 1. 2011
The molecular basis of pathogenicity of H5N1 highly pathogenic avian influenza (HPAI) viruses in chickens remains largely unknown. H5N1 A/chicken/Yamaguchi/7/2004 virus (CkYM7) replicates rapidly in macrophages and vascular endothelial cells in chickens, causing sudden death without fever or gross lesions, while H5N1 A/duck/Yokohama/aq10/2003 virus (DkYK10) induces high fever, severe gross lesions, and a prolonged time to death, despite the 98% amino acid identity between the two viruses. To explore the molecular basis of this difference in pathogenicity, a series of eight single-gene reassortant viruses from these HPAI viruses were compared for pathogenicity in chickens. Two reassortants possessing the NP or PB2 gene from DkYK10 in the CkYM7 background reduced pathogenicity compared to other reassortants or CkYM7. Inversely, reassortants possessing the NP or PB2 gene of CkYM7 in the DkYK10 background (rgDkYK-PB2(Ck), rgDkYK-NP(Ck)) replicated quickly and reached higher titers than DkYK10, accompanied by more rapid and frequent apoptosis of macrophages. The rgDkYK-NP(Ck) and rgDkYK-PB2(Ck) reassortants also replicated more rapidly in chicken embryo fibroblasts (CEFs) than did rgDkYK10, but replication of these viruses was similar to that of CkYM7 and DkYK10 in duck embryo fibroblasts. A comparison of pathogenicities of seven rgDkYK10 mutants with a single amino acid substitution in NP(Dk) demonstrated that valine at position 105 in the NP(Ck) was responsible for the increased pathogenicity in chickens. NP(Ck), NP(105V), and PB2(Ck) enhanced the polymerase activity of DkYK10 in CEFs. These results indicate that both NP and PB2 contribute to the high pathogenicity of the H5N1 HPAI viruses in chickens, and valine at position 105 of NP may be one of the determinants for adaptation of avian influenza viruses from ducks to chickens.Full Text Article
|Lentivirus-mediated RNA interference targeting E2F-1 inhibits human gastric cancer MGC-803 cell growth in vivo. |
Xiao Tong Wang,Yu Bo Xie,Qiang Xiao
Experimental & molecular medicine 43 2011
The E2F-1 transcription factor is post-translationally modified and stabilized in response to various forms of DNA damage to regulate the expression of cell-cycle and pro-apoptotic genes. The sustained overexpression of E2F-1 is a characteristic feature of gastric cancer. In this study, we investigated the role of short hairpin RNA (shRNA) targeting E2F-1 gene on human gastric cancer MGC-803 cell growth in vivo, and preliminarily revealed the mechanism. Thus, we constructed recombinant pGCSIL-GFP-shRNA-E2F-1 lentiviral vector to knock down E2F-1 expression in human gastric cancer MGC-803 cells in vivo, and studied the effect of E2F-1 shRNA on growth of MGC-803 tumor and evaluated its treatment efficacy. Our data demonstrated that in a mouse model of established gastric cancer, intratumor injection of lentiviral shRNA targeting E2F-1 definitely decreased the endogenous E2F-1 mRNA and protein expression in MGC-803 tumor, and inhibited tumor growth and promoted tumor cells apoptosis. Moreover, we found that E2F-1 shRNA increased the expression of phosphatase and tensin homolog (PTEN), activated caspase-3 and caspase-9, and suppressed nuclear factor (NF)-?B expression in tumor tissue as determined by reverse transcription (RT)-PCR and western blotting. In summary, shRNA targeting of E2F-1 can effectively inhibits human gastric cancer MGC-803 cell growth in vivo and may be a potential therapeutic strategy for gastric cancer.Full Text Article
|White matter damage and the effect of matrix metalloproteinases in type 2 diabetic mice after stroke. |
Chen J, Cui X, Zacharek A, Cui Y, Roberts C, Chopp M
Stroke 42 445-52. Epub 2010 Dec 30. 2011
BACKGROUND AND PURPOSE: Diabetes mellitus leads to a higher risk of ischemic stroke and worse outcome compared to the general population. However, there have been few studies on white matter (WM) damage after stroke in diabetes mellitus. We therefore investigated WM damage after stroke in mice with diabetes mellitus.METHODS: BKS.Cg-m(+/+)Lepr(db)/J (db/db) type 2 diabetes mellitus mice and db(+) non-diabetes mellitus mice were subjected to middle cerebral artery occlusion. Functional outcome, immunostaining, zymography, Western blot, and polymerase chain reaction were used.RESULTS: After stroke, mice with diabetes mellitus exhibited significantly increased lesion volume and brain hemorrhagic and neurological deficits compared to mice without diabetes mellitus. Bielshowsky silver, luxol fast blue, amyloid precursor protein, and NG2 expression were significantly decreased, indicating WM damage, and matrix metalloproteinase (MMP)-9 activity was significantly increased in the ischemic brain of mice with diabetes mellitus. Subanalysis of similar lesions in mice with and without diabetes mellitus demonstrated mice with diabetes mellitus had significantly increased WM damage than in mice without diabetes mellitus (P<0.05). To investigate the mechanism underlying diabetes mellitus-induced WM damage, oxygen-glucose deprivation-stressed premature oligodendrocyte and primary cortical neuron cultures were used. High glucose increased MMP-2, MMP-9, cleaved caspase-3 levels, and apoptosis, as well as decreased cell survival and dendrite outgrowth in cultured primary cortical neuron. High glucose increased MMP-9, cleaved caspase-3 level, and apoptosis, and decreased cell proliferation and cell survival in cultured oligodendrocytes. Inhibition of MMP by GM6001 treatment significantly decreased high glucose-induced cell death and apoptosis in cultured primary cortical neuron and oligodendrocytes but did not alter dendrite outgrowth in primary cortical neuron.CONCLUSIONS: Mice with diabetes mellitus have increased brain hemorrhage and show more severely injured WM than mice without diabetes mellitus after stroke. MMP-9 upregulated in mice with diabetes mellitus may exacerbate WM damage after stroke in mice with diabetes mellitus.
|Adenovirus E2F1 overexpression sensitizes LNCaP and PC3 prostate tumor cells to radiation in vivo. |
Udayakumar TS, Stoyanova R, Hachem P, Ahmed MM, Pollack A
Int J Radiat Oncol Biol Phys 79 549-58. 2011
PURPOSE: We previously showed that E2F1 overexpression radiosensitizes prostate cancer cells in vitro. Here, we demonstrate the radiosensitization efficacy of adenovirus (Ad)-E2F1 infection in growing (orthotopic) LNCaP and (subcutaneous) PC3 nude mice xenograft tumors.METHODS AND MATERIALS: Ad-E2F1 was injected intratumorally in LNCaP (3 × 10(8) plaque-forming units [PFU]) and PC3 (5 × 10(8) PFU) tumors treated with or without radiation. LNCaP tumor volumes (TV) were measured by magnetic resonance imaging, caliper were used to measure PC3 tumors, and serum prostate-specific antigen (PSA) levels were determined by enzyme-linked immunosorbent assay. Apoptosis was measured by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling, and key proteins involved in cell death signaling were analyzed by Western blotting.RESULTS: Intracellular overexpression of Ad-E2F1 had a significant effect on the regression of TV and reduction of PSA levels relative to that of adenoviral luciferase (Ad-Luc)-infected control. The in vivo regressing effect of Ad-E2F1 on LNCaP tumor growth was significant (PSA, 34 ng/ml; TV, 142 mm(3)) compared to that of Ad-Luc control (PSA, 59 ng/ml; TV, 218 mm(3); p <0.05). This effect was significantly enhanced by radiation therapy (compare: Ad-E2F1+RT/PSA, 16 ng/ml, and TV, 55 mm(3) to Ad-Luc+RT/PSA, 42 ng/ml, and TV, 174 mm(3), respectively; p <0.05). For PC3 tumors, the greatest effect was observed with Ad-E2F1 infection alone; there was little or no effect when radiotherapy (RT) was combined. However, addition of RT enhanced the level of in situ apoptosis in PC3 tumors. Molecularly, addition of Ad-E2F1 in a combination treatment abrogated radiation-induced BCL-2 protein expression and was associated with an increase in activated BAX, and together they caused a potent radiosensitizing effect, irrespective of p53 and androgen receptor functional status.CONCLUSIONS: We show here for the first time that ectopic overexpression of E2F1 in vivo, using an adenoviral vector, significantly inhibits orthotopic p53 wild-type LNCaP tumors and subcutaneous p53-null PC3 tumors in nude mice. Furthermore, we demonstrate that E2F1 strongly sensitizes LNCaP tumors to RT. These findings suggest that E2F1 overexpression can sensitize prostate tumor cells in vivo, independent of p53 or androgen receptor status.Copyright Â© 2011 Elsevier Inc. All rights reserved.
|Dicer1 depletion in male germ cells leads to infertility due to cumulative meiotic and spermiogenic defects. |
Romero, Yannick, et al.
PLoS ONE, 6: e25241 (2011) 2011
Spermatogenesis is a complex biological process that requires a highly specialized control of gene expression. In the past decade, small non-coding RNAs have emerged as critical regulators of gene expression both at the transcriptional and post-transcriptional level. DICER1, an RNAse III endonuclease, is essential for the biogenesis of several classes of small RNAs, including microRNAs (miRNAs) and endogenous small interfering RNAs (endo-siRNAs), but is also critical for the degradation of toxic transposable elements. In this study, we investigated to which extent DICER1 is required for germ cell development and the progress of spermatogenesis in mice.
|Physical exercise stimulates autophagy in normal skeletal muscles but is detrimental for collagen VI-deficient muscles. |
Paolo Grumati,Luisa Coletto,Alvise Schiavinato,Silvia Castagnaro,Enrico Bertaggia,Marco Sandri,Paolo Bonaldo
Autophagy 7 2011
Autophagy is a catabolic process that provides the degradation of altered/damaged organelles through the fusion between autophagosomes and lysosomes. Proper regulation of the autophagic flux is fundamental for the homeostasis of skeletal muscles in physiological conditions and in response to stress. Defective as well as excessive autophagy is detrimental for muscle health and has a pathogenic role in several forms of muscle diseases. Recently, we found that defective activation of the autophagic machinery plays a key role in the pathogenesis of muscular dystrophies linked to collagen VI. Impairment of the autophagic flux in collagen VI null (Col6a1–/–) mice causes accumulation of dysfunctional mitochondria and altered sarcoplasmic reticulum, leading to apoptosis and degeneration of muscle fibers. Here we show that physical exercise activates autophagy in skeletal muscles. Notably, physical training exacerbated the dystrophic phenotype of Col6a1–/– mice, where autophagy flux is compromised. Autophagy was not induced in Col6a1–/– muscles after either acute or prolonged exercise, and this led to a marked increase of muscle wasting and apoptosis. These findings indicate that proper activation of autophagy is important for muscle homeostasis during physical activity.
|Theta-burst transcranial magnetic stimulation alters cortical inhibition. |
Benali A, Trippe J, Weiler E, Mix A, Petrasch-Parwez E, Girzalsky W, Eysel UT, Erdmann R, Funke K
J Neurosci 31 1193-203. 2011
Human cortical excitability can be modified by repetitive transcranial magnetic stimulation (rTMS), but the cellular mechanisms are largely unknown. Here, we show that the pattern of delivery of theta-burst stimulation (TBS) (continuous versus intermittent) differently modifies electric activity and protein expression in the rat neocortex. Intermittent TBS (iTBS), but not continuous TBS (cTBS), enhanced spontaneous neuronal firing and EEG gamma band power. Sensory evoked cortical inhibition increased only after iTBS, although both TBS protocols increased the first sensory response arising from the resting cortical state. Changes in the cortical expression of the calcium-binding proteins parvalbumin (PV) and calbindin D-28k (CB) indicate that changes in spontaneous and evoked cortical activity following rTMS are in part related to altered activity of inhibitory systems. By reducing PV expression in the fast-spiking interneurons, iTBS primarily affected the inhibitory control of pyramidal cell output activity, while cTBS, by reducing CB expression, more likely affected the dendritic integration of synaptic inputs controlled by other classes of inhibitory interneurons. Calretinin, the third major calcium-binding protein expressed by another class of interneurons was not affected at all. We conclude that different patterns of TBS modulate the activity of inhibitory cell classes differently, probably depending on the synaptic connectivity and the preferred discharge pattern of these inhibitory neurons.
|Inhibition of the catalytic function of activation-induced cytidine deaminase promotes apoptosis of germinal center b cells in BXD2 mice. |
Hsu HC, Yang P, Wu Q, Wang JH, Job G, Guentert T, Li J, Stockard CR, Le TV, Chaplin DD, Grizzle WE, Mountz JD
Arthritis and rheumatism 63 2038-48. doi 2011
|Rheb is essential for murine development. |
Goorden, Susanna M I, et al.
Mol. Cell. Biol., 31: 1672-8 (2011) 2011
Ras homolog enriched in brain (Rheb) couples growth factor signaling to activation of the target of rapamycin complex 1 (TORC1). To study its role in mammals, we generated a Rheb knockout mouse. In contrast to mTOR or regulatory-associated protein of mTOR (Raptor) mutants, the inner cell mass of Rheb(-/-) embryos differentiated normally. Nevertheless, Rheb(-/-) embryos died around midgestation, most likely due to impaired development of the cardiovascular system. Rheb(-/-) embryonic fibroblasts showed decreased TORC1 activity, were smaller, and showed impaired proliferation. Rheb heterozygosity extended the life span of tuberous sclerosis complex 1-deficient (Tsc1(-/-)) embryos, indicating that there is a genetic interaction between the Tsc1 and Rheb genes in mouse.
|Effects of sevoflurane on neuronal cell damage after severe cerebral ischemia in rats. |
Park HP, Jeong EJ, Kim MH, Hwang JW, Lim YJ, Min SW, Kim CS, Jeon YT
Korean journal of anesthesiology 61 327-331. Epub 2011 Oct 22. 2011
|Tooth-bone morphogenesis during postnatal stages of mouse first molar development. |
Lungová V, Radlanski RJ, Tucker AS, Renz H, Míšek I, Matalová E
Journal of anatomy 218 699-716. doi 2011
The first mouse molar (M1) is the most common model for odontogenesis, with research particularly focused on prenatal development. However, the functional dentition forms postnatally, when the histogenesis and morphogenesis of the tooth is completed, the roots form and the tooth physically anchors into the jaw. In this work, M1 was studied from birth to eruption, assessing morphogenesis, proliferation and apoptosis, and correlating these with remodeling of the surrounding bony tissue. The M1 completed crown formation between postnatal (P) days 0-2, and the development of the tooth root was initiated at P4. From P2 until P12, cell proliferation in the dental epithelium reduced and shifted downward to the apical region of the forming root. In contrast, proliferation was maintained or increased in the mesenchymal cells of the dental follicle. At later stages, before tooth eruption (P20), cell proliferation suddenly ceased. This withdrawal from the cell cycle correlated with tooth mineralization and mesenchymal differentiation. Apoptosis was observed during all stages of M1 postnatal morphogenesis, playing a role in the removal of cells such as osteoblasts in the mandibular region and working together with osteoclasts to remodel the bone around the developing tooth. At more advanced developmental stages, apoptotic cells and bodies accumulated in the cell layers above the tooth cusps, in the path of eruption. Three-dimensional reconstruction of the developing postnatal tooth and bone indicates that the alveolar crypts form by resorption underneath the primordia, whereas the ridges form by active bone growth between the teeth and roots to form a functional complex.© 2011 The Authors. Journal of Anatomy © 2011 Anatomical Society of Great Britain and Ireland.
|Vascular smooth muscle Jak2 deletion prevents angiotensin II-mediated neointima formation following injury in mice. |
Kirabo A, Oh SP, Kasahara H, Wagner KU, Sayeski PP
J Mol Cell Cardiol 2011
The in vitro treatment of vascular smooth muscle cells (VSMC) with angiotensin II (Ang II) causes Janus kinase 2 (Jak2) to interact with the Ang II type 1 receptor (AT(1)-R) resulting in enhanced cell growth. However, the role that Jak2 plays in AT(1)-R-mediated vascular cell growth and remodeling in vivo is less clear. We hypothesized that in vivo, Jak2 plays a rate-limiting role in Ang II-mediated neointima formation following vascular injury. Using the Cre-loxP system, we conditionally ablated Jak2 from the VSMC of mice. We found that these mice are protected from Ang II-mediated neointima formation following iron chloride-induced vascular injury. In addition, the VSMC Jak2 null mice were protected from injury-induced vascular fibrosis and the pathological loss of the contractile marker, smooth muscle α-actin. Finally, when compared to controls, the VSMC Jak2 null mice exhibited significantly less Ang II-induced VSMC proliferation and migration in vitro and in vivo and more apoptosis. These results suggest that Jak2 plays a central role in the causation of Ang II-induced neointima formation following vascular injury and may provide a novel target for the prevention of neointima formation.Copyright © 2011 Elsevier Ltd. All rights reserved.
|Defective survival of proliferating Sertoli cells and androgen receptor function in a mouse model of the ATR-X syndrome. |
Bagheri-Fam S, Argentaro A, Svingen T, Combes AN, Sinclair AH, Koopman P, Harley VR
Hum Mol Genet 2011
X-linked ATR-X (alpha thalassemia, mental retardation, X-linked) syndrome in males is characterized by mental retardation, facial dysmorphism, alpha thalassemia and urogenital abnormalities, including small testes. It is unclear how mutations in the chromatin-remodeling protein ATRX cause these highly specific clinical features, since ATRX is widely expressed during organ development. To investigate the mechanisms underlying the testicular defects observed in ATR-X syndrome, we generated ScAtrxKO (Sertoli cell Atrx knockout) mice with Atrx specifically inactivated in the supporting cell lineage (Sertoli cells) of the mouse testis. ScAtrxKO mice developed small testes and discontinuous tubules, due to prolonged G2/M phase and apoptosis of proliferating Sertoli cells during fetal life. Apoptosis might be a consequence of the cell cycle defect. We also found that the onset of spermatogenesis was delayed in postnatal mice, with a range of spermatogenesis defects evident in adult ScAtrxKO mice. ATRX and the androgen receptor (AR) physically interact in the testis and in the Sertoli cell line TM4 and co-operatively activate the promoter of Rhox5, an important direct AR target. We also demonstrate that ATRX directly binds to the Rhox5 promoter in TM4 cells. Finally, gene expression of Rhox5 and of another AR-dependent gene, Spinlw1, was reduced in ScAtrxKO testes. These data suggest that ATRX can directly enhance the expression of androgen-dependent genes through physical interaction with AR. Recruitment of ATRX by DNA sequence-specific transcription factors could be a general mechanism by which ATRX achieves tissue-specific transcriptional regulation which could explain the highly specific clinical features of ATR-X syndrome when ATRX is mutated.
|The p53 Inhibitor MDM2 Facilitates Sonic Hedgehog-Mediated Tumorigenesis and Influences Cerebellar Foliation. |
Malek R, Matta J, Taylor N, Perry ME, Mendrysa SM
PLoS One 6 e17884. 2011
Disruption of cerebellar granular neuronal precursor (GNP) maturation can result in defects in motor coordination and learning, or in medulloblastoma, the most common childhood brain tumor. The Sonic Hedgehog (Shh) pathway is important for GNP proliferation; however, the factors regulating the extent and timing of GNP proliferation, as well as GNP differentiation and migration are poorly understood. The p53 tumor suppressor has been shown to negatively regulate the activity of the Shh effector, Gli1, in neural stem cells; however, the contribution of p53 to the regulation of Shh signaling in GNPs during cerebellar development has not been determined. Here, we exploited a hypomorphic allele of Mdm2 (Mdm2(puro)), which encodes a critical negative regulator of p53, to alter the level of wild-type MDM2 and p53 in vivo. We report that mice with reduced levels of MDM2 and increased levels of p53 have small cerebella with shortened folia, reminiscent of deficient Shh signaling. Indeed, Shh signaling in Mdm2-deficient GNPs is attenuated, concomitant with decreased expression of the Shh transducers, Gli1 and Gli2. We also find that Shh stimulation of GNPs promotes MDM2 accumulation and enhances phosphorylation at serine 166, a modification known to increase MDM2-p53 binding. Significantly, loss of MDM2 in Ptch1(+/-) mice, a model for Shh-mediated human medulloblastoma, impedes cerebellar tumorigenesis. Together, these results place MDM2 at a major nexus between the p53 and Shh signaling pathways in GNPs, with key roles in cerebellar development, GNP survival, cerebellar foliation, and MB tumorigenesis.Full Text Article
|Intraperitoneal aminoguanidine improves sciatic nerve ischemia-reperfusion injury in male sprague-dawley rats. |
Mohsen Alipour,Mohammad Reza Gholami,Iraj Jafari Anarkooli,Davood Sohrabi,Javad Tajki,Maryam Pourheidar
Cellular and molecular neurobiology 31 2011
The present work was designed to investigate the potential protective effects of post-ischemic treatment with aminoguanidine (AG) on sciatic nerve ischemia/reperfusion (I/R) injury in rat. Seventy-two rats were divided into 12 groups (n = 6). We used ischemia model in these groups by occluding the right common iliac and femoral arteries for 3 h with a silk suture 6-0 using slipknot technique. Treatment groups (2, 4, 6, 8, 10, and 12) received 150 mg/kg AG intraperitoneally 24 h after induction of ischemia. After certain time intervals of reperfusion (2, 4, 7, 14, and 28 days), the function of the hind limb was assessed using behavioral scores based on gait, racing reflex, toe spread, pinch sensitivity, paw position, and grasp. After euthanasia, sciatic nerves were removed at the end of reperfusion times and sections were cut at 5 ?m, then were stained for light microscopy studies and graded for ischemic fiber degeneration (IFD), edema, and apoptosis. Maximal behavioral deficit occurred at 7 days of reperfusion. The comparison of behavioral score pertaining to the control and AG groups revealed significant differences and showed also a better time course in recovery (P < 0.05). Other than 3 and 4 groups, the amount of edema in AG treatment groups showed significant differences compared with control groups (P < 0.05). IFD was also significantly decreased in the AG treatment groups than controls. Most importantly, I/R-induced apoptosis were improved significantly on the 4th, 7(th), and 14th days of reperfusion in AG-treated groups compared to controls. In conclusion, our findings suggest that post-ischemic administration of AG exhibits protective effect against sciatic nerve I/R injury.
|Deletion of the bis gene results in a Marked increase in the production of corticosterone that is associated with thymic atrophy in Mice. |
Youn DY, Yoon JS, Kim YK, Yeum CE, Lee SB, Youn HJ, Tsujimoto Y, Lee JH
American journal of physiology Endocrinology and metabolism 301 E223-31. Epub 2011 May 3. 2011
Bis (Bag3) is known to be involved in cell survival, migration, the regulating of chaperones, and protein quality control. We reported recently on the production of bis gene-deleted mice, which show early lethality within 3 wk after birth with a phenotype showing severe malnutrition and shrinkage of the thymus. In this report, we provide evidence to show that an intrinsic problem of adrenal gland is the the primary cause for the severe atrophy of the thymus in bis(-/-) mice. The bis(-/-) mice show significantly higher levels of corticosterone, but CRH and ACTH levels were considerably lower than those of wild littermates. The transcription of steroidogenic enzymes was increased in the adrenal glands of bis(-/-) mice, accompanied by an increase in the thickness of the zona reticularis. An analysis of thymus tissue from bis(-/-) mice revealed that the severe atrophy of the thymus is due to the specific loss of immature double-positive (CD4(+)CD8(+)) cortical thymocytes by apoptosis, as evidenced by immunohistochemical examination and flow cytometric analysis, which were restored by injection of an inhibitor of glucocorticoid synthesis. In vitro cultures of thymocytes with increasing doses of dexamethasone exhibited a similar degree of apoptosis between wild and bis(-/-) thymocytes. The corticosterone levels from fasted wild littermates were one-half those of bis(-/-) mice, although serum glucose levels were similar. Thus, the deletion of the bis gene resulted in the intrinsic defect in the adrenal gland, leading to a marked increase in glucocorticoid levels, probably upon starvation stress, which accounts for the massive apoptosis of the thymus.
|Cyclooxygenase-2 overexpression in chronic inflammation associated with benign prostatic hyperplasia: is it related to apoptosis and angiogenesis of prostate cancer |
Kim BH, Kim CI, Chang HS, Choe MS, Jung HR, Kim DY, Park CH
Korean journal of urology 52 253-9. Epub 2011 Apr 22. 2011
Full Text Article
|Effect of Maternal and postweaning folic acid supplementation on colorectal cancer risk in the offspring. |
Sie KK, Medline A, van Weel J, Sohn KJ, Choi SW, Croxford R, Kim YI
Background Intrauterine and early life exposure to folic acid has significantly increased in North America owing to folic acid fortification, widespread supplemental use and periconceptional folic acid supplementation. The effect of maternal and postweaning folic acid supplementation on colorectal cancer risk in the offspring was investigated. Methods Female rats were placed on a control or supplemental (2.5× the control) diet prior to mating and during pregnancy and lactation. At weaning, male pups from each maternal diet group were randomised to the control or supplemental diet (n=55 per each of the four maternal/pup diet groups) for 31 weeks and colorectal cancer was induced by azoxymethane at 5 weeks of age. At necropsy, colorectal cancer parameters as well as colorectal epithelial proliferation, apoptosis and global DNA methylation were determined in the offspring. Results Maternal, but not postweaning, folic acid supplementation significantly reduced the odds of colorectal adenocarcinoma by 64% in the offspring (OR 0.36; 95% CI 0.18 to 0.71; p=0.003). Pups from the dams fed the control diet that were given postweaning folic acid supplementation had significantly higher tumour multiplicity and burden than other groups (p<0.05). Maternal and postweaning folic acid supplementation interacted in a manner that decreased rectal epithelial proliferation (p<0.05). Both maternal and postweaning folic acid supplementation significantly decreased DNA damage in the rectum (p<0.05). Maternal folic acid supplementation significantly increased (p=0.007), whereas postweaning supplementation significantly decreased (p<0.001), colorectal global DNA methylation. Conclusions The data suggest for the first time that maternal folic acid supplementation at the level equivalent to the average postfortification total folate intake in North America and to that recommended to women at reproductive age protects against the development of colorectal cancer in the offspring. This protective effect may be mediated in part by increased global DNA methylation and decreased epithelial proliferation and DNA damage in the colorectum.
|Targeting fibroblast growth factor receptor 3 enhances radiosensitivity in human squamous cancer cells. |
Uzawa K, Ishigami T, Fushimi K, Kawata T, Shinozuka K, Kasamatsu A, Sakamoto Y, Ogawara K, Shiiba M, Bukawa H, Ito H, Tanzawa H
Conventional therapies including radiation therapy cannot cure squamous cell carcinoma (SCC), and new treatments are clearly required. Our recent studies have shown that SCC cell lines exhibiting radioresistance show significant upregulation of the fibroblast growth factor receptor 3 (FGFR3) gene. We hypothesized that inhibiting FGFR3 would suppress tumor cell radioresistance and provide a new treatment approach for human SCCs. In the present study, we found that RNA interference-mediated FGFR3 depletion in HSC-2 cells, a radioresistant cell line, induced radiosensitivity and inhibited tumor growth. Use of an FGFR3 inhibitor (PD173074) obtained similar results with suppression of the autophosphorylation extracellular signal-regulated kinase pathway in HSC-2 cells and lung cancer cell lines. Moreover, the antitumor growth effect of the combination of PD173074 and radiation in vivo was also greater than that with either drug alone or radiation alone. Our results provided novel information on which to base further mechanistic study of radiosensitization by inhibiting FGFR3 in human SCC cells and for developing strategies to improve outcomes with concurrent radiotherapy.Oncogene advance online publication, 16 May 2011; doi:10.1038/onc.2011.159.
|Vitamin E succinate induced apoptosis and enhanced chemosensitivity to paclitaxel in human bladder cancer cells in vitro and in vivo. |
Kanai K, Kikuchi E, Mikami S, Suzuki E, Uchida Y, Kodaira K, Miyajima A, Ohigashi T, Nakashima J, Oya M
Cancer Sci 101 216-23. Epub 2009 Sep 14. 2010
There have been several studies on the antitumor activities of vitamin E succinate (alpha-TOS) as complementary and alternative medicine. In the present study, we investigated the cytotoxic effect of alpha-TOS and the enhancement of chemosensitivity to paclitaxel by alpha-TOS in bladder cancer. KU-19-19 and 5637 bladder cancer cell lines were cultured in alpha-TOS and/or paclitaxel in vitro. Cell viability, flow cytometric analysis, and nuclear factor-kappa B (NF-kappaB) activity were analyzed. For in vivo therapeutic experiments, pre-established KU-19-19 tumors were treated with alpha-TOS and/or paclitaxel. In KU-19-19 and 5637 cells, the combination treatment resulted in a significantly higher level of growth inhibition, and apoptosis was significantly induced by the combination treatment. NF-kappaB was activated by paclitaxel; however, the activation of NF-kappaB was inhibited by alpha-TOS. Also, the combination treatment significantly inhibited tumor growth in mice. In the immunostaining of the tumors, apoptosis was induced and proliferation was inhibited by the combination treatment. Combination treatment of alpha-TOS and paclitaxel showed promising anticancer effects in terms of inhibiting bladder cancer cell growth and viability in vitro and in vivo. One of the potential mechanisms by which the combination therapy has synergistic cytotoxic effects against bladder cancer may be that alpha-TOS inhibits NF-kappaB induced by chemotherapeutic agents.
|Open blunt crush injury of different severity determines nature and extent of local tissue regeneration and repair. |
Stratos I, Graff J, Rotter R, Mittlmeier T, Vollmar B
J Orthop Res 28 950-7. 2010
Insufficiency of skeletal muscle regeneration is often accompanied with functional deficiencies. The goal of our study was to assess the restoration of peripheral muscle upon injury of different severity. Blunt crush injury of the soleus muscle in rats was induced by a clamp and stepwise amplified in severity by rising the locking level of the clamp, resulting in three different groups (1x lock; 2x lock; 3x lock; n = 30 animals per group). After assessment of the fast twitch and tetanic contraction capacity at days 1, 4, 7, 14, and 42 postinjury sampling of muscle tissue served for analysis of cell proliferation, including satellite cells, apoptosis, and leukocyte infiltration. Contraction force analysis demonstrated significantly higher values of relative muscle strength in the 1x lock group compared to the two other groups over 42 days. Calculation of the twitch-to-tetanic force ratio revealed significantly higher mean values at days 1, 7, and 14 in the animals of group 2x lock and 3x lock, indicating a transformation toward a fast-twitching muscular phenotype. Moreover, cell proliferation during the first 4 days was found dependent on the severity of muscle injury in that the higher the severity the higher the proliferation. At the same time, cell apoptosis was found increased, and at day 1 the local leukocyte infiltration was significantly higher in the 3x lock compared to the 1x lock group. These data indicate that severity of injury correlates with local repair responses, which, however, are not necessarily sufficient to fully restore muscle function. (c) 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.
|Absence of glutathione peroxidase 4 affects tumor angiogenesis through increased 12/15-lipoxygenase activity. |
Manuela Schneider,Markus Wortmann,Pankaj Kumar Mandal,Warangkana Arpornchayanon,Katharina Jannasch,Frauke Alves,Sebastian Strieth,Marcus Conrad,Heike Beck
Neoplasia (New York, N.Y.) 12 2010
The selenoenzyme glutathione peroxidase 4 (GPx4) has been described to control specific cyclooxygenases (COXs) and lipoxygenases (LOXs) that exert substantiated functions in tumor growth and angiogenesis. Therefore, we hypothesized a putative regulatory role of GPx4 during tumor progression and created transformed murine embryonic fibroblasts with inducible disruption of GPx4. GPx4 inactivation caused rapid cell death in vitro, which could be prevented either by lipophilic antioxidants or by 12/15-LOX-specific inhibitors, but not by inhibitors targeting other LOX isoforms or COX. Surprisingly, transformed GPx4(+/-) cells did not die when grown in Matrigel but gave rise to tumor spheroids. Subcutaneous implantation of tumor cells into mice resulted in knockout tumors that were indistinguishable in volume and mass in comparison to wild-type tumors. However, further analysis revealed a strong vascular phenotype. We observed an increase in microvessel density as well as a reduction in the number of large diameter vessels covered by smooth muscle cells. This phenotype could be linked to increased 12/15-LOX activity that was accompanied by an up-regulation of basic fibroblast growth factor and down-regulation of vascular endothelial growth factor A protein expression. Indeed, pharmacological inhibition of 12/15-LOX successfully reversed the tumor phenotype and led to normalized vessel morphology. Thus, we conclude that GPx4, through controlling 12/15-LOX activity, is an important regulator of tumor angiogenesis as well as vessel maturation.Full Text Article
|Senescence induction in human fibroblasts and hematopoietic progenitors by leukemogenic fusion proteins. |
Wajapeyee N, Wang SZ, Serra RW, Solomon PD, Nagarajan A, Zhu X, Green MR
Blood 115 5057-60. Epub 2010 Apr 26. 2010
Hematologic malignancies are typically associated with leukemogenic fusion proteins, which are required to maintain the oncogenic state. Previous studies have shown that certain oncogenes that promote solid tumors, such as RAS and BRAF, can induce senescence in primary cells, which is thought to provide a barrier to tumorigenesis. In these cases, the activated oncogene elicits a DNA damage response (DDR), which is essential for the senescence program. Here we show that 3 leukemogenic fusion proteins, BCR-ABL, CBFB-MYH11, and RUNX1-ETO, can induce senescence in primary fibroblasts and hematopoietic progenitors. Unexpectedly, we find that senescence induction by BCR-ABL and CBFB-MYH11 occurs through a DDR-independent pathway, whereas RUNX1-ETO induces senescence in a DDR-dependent manner. All 3 fusion proteins activate the p38 MAPK pathway, which is required for senescence induction. Our results reveal diverse pathways for oncogene-induced senescence and further suggest that leukemias harbor genetic or epigenetic alterations that inactivate senescence induction genes.
|Sinomenine pretreatment attenuates cold ischemia/reperfusion injury in rats: the role of heme oxygenase-1. |
Song S, Shen X, Tang Y, Wang Z, Guo W, Ding G, Wang Q, Fu Z
Int Immunopharmacol 10 679-84. Epub 2010 Mar 27. 2010
Ischemia/reperfusion (I/R) injury can be characterized as an inflammatory response including recruitment of inflammatory cells to a post-ischemic organ or tissue and a cascade of mediators. Sinomenine (SIN), a pure alkaloid extracted from the Chinese medical plant Sinomenium acutum, has been used to treat various inflammatory diseases including rheumatism and arthritis. However, whether SIN can attenuate I/R injury has not previously been examined. Using a syngeneic orthotopic liver transplantation model in rats, we investigated the effect of SIN on hepatic I/R injury, in particular its effect on heme oxygenase-1 (HO-1) induction and its hepatocellular protective effect. To our knowledge, our results were the first to show that: (a) SIN pretreatment was able to induce HO-1 expression in donor livers in a dose dependent manner; (b) SIN pretreatment protected the liver graft from cold I/R injury; and (c) the protective effect of SIN was, at least in part, mediated by HO-1, as proved by the fact that inhibiting HO-1 activity with zinc protoporphyrin (ZnPP) reduced the protection. Thus, SIN deserves further exploration as a novel agent to attenuate I/R injury.
|Small peptide inhibitor of JNKs protects against MPTP-induced nigral dopaminergic injury via inhibiting the JNK-signaling pathway. |
Pan J, Qian J, Zhang Y, Ma J, Wang G, Xiao Q, Chen S, Ding J
Laboratory investigation; a journal of technical methods and 90 156-167 2010
Increasing evidence suggests that apoptosis may be the mechanism underlying cell death in selective loss of nigral dopaminergic neurons in Parkinson's disease (PD). Previous studies strongly suggested that c-Jun N-terminal kinase (JNK) signaling pathway has a critical role in the animal model with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD. In this study, we report the inhibitory effect of a peptide designated as Tat-JBD on JNKs activation. The sequence of Tat is corresponding to the cell-membrane transduction domain of human immunodeficiency virus-type 1 (HIV-1) and the sequence of an 11-amino acid peptide is corresponding to the residues of JNK-binding domain (JBD) on JNK-interacting protein-1 (JIP-1). Tat-JBD is confirmed to perturb the assembly of JIP-1-JNKs complex, inhibit the activation of JNKs induced by MPTP and consequently diminish the phosphorylation of c-Jun. It also inhibits the phosphorylation of Bcl-2 and the releasing of Bax from Bcl-2/Bax dimmers, sequentially attenuates the translocation of Bax to mitochondria, the release of cytochrome c, the activation of caspase3 and the hydrolyzation of poly-ADP-ribose-polymerase. The death of dopaminergic neurons and the loss of dopaminergic axon in the striatum were significantly suppressed by infusion of the peptide Tat-JBD in MPTP-treated mice. Our findings imply that Tat-JBD offers neuroprotection against MPTP injury via inhibiting the JNK-signaling pathway, and may provide a promising therapeutic approach for PD.
|Coactivation of GABA receptors inhibits the JNK3 apoptotic pathway via disassembly of GluR6-PSD-95-MLK3 signaling module in KA-induced seizure. |
Chong Li,Bo Xu,Wei-Wei Wang,Xiu-Ju Yu,Jie Zhu,Hong-Min Yu,Dong Han,Dong-Sheng Pei,Guang-Yi Zhang
Epilepsia 51 2010
Past work has demonstrated that kainic acid (KA)-induced seizures could cause the enhancement of excitation and lead to neuronal death in rat hippocampus. To counteract such an imbalance between excitation and inhibition, we designed experiments by activating the inhibitory gamma-aminobutyric acid (GABA) receptor to investigate whether such activation suppresses the excitatory glutamate signaling induced by KA and to elucidate the underlying molecular mechanisms.
|N-acetylcysteine prevents nitric oxide-induced chondrocyte apoptosis and cartilage degeneration in an experimental model of osteoarthritis. |
Shuji Nakagawa,Yuji Arai,Osam Mazda,Tsunao Kishida,Kenji A Takahashi,Kei Sakao,Masazumi Saito,Kuniaki Honjo,Jiro Imanishi,Toshikazu Kubo
Journal of orthopaedic research : official publication of the Orthopaedic Research Society 28 2010
We investigated whether N-acetylcysteine (NAC), a precursor of glutathione, could protect rabbit articular chondrocytes against nitric oxide (NO)-induced apoptosis and could prevent cartilage destruction in an experimental model of osteoarthritis (OA) in rats. Isolated chondrocytes were treated with various concentrations of NAC (0-2 mM). Apoptosis was induced by 0.75 mM sodium nitroprusside (SNP) dehydrate, which produces NO. Cell viability was assessed by MTT assay, while apoptosis was evaluated by Hoechst 33342 and TUNEL staining. Intracellular reactive oxygen species (ROS) and glutathione levels were measured, and expression of p53 and caspase-3 were determined by Western blotting. To determine whether intraarticular injection of NAC prevents cartilage destruction in vivo, cartilage samples of an OA model were subjected to H&E, Safranin O, and TUNEL staining. NAC prevented NO-induced apoptosis, ROS overproduction, p53 up-regulation, and caspase-3 activation. The protective effects of NAC were significantly blocked by buthionine sulfoximine, a glutathione synthetase inhibitor, indicating that the apoptosis-preventing activity of NAC was mediated by glutathione. Using a rat model of experimentally induced OA, we found that NAC also significantly prevented cartilage destruction and chondrocyte apoptosis in vivo. These results indicate that NAC inhibits NO-induced apoptosis of chondrocytes through glutathione in vitro, and inhibits chondrocyte apoptosis and articular cartilage degeneration in vivo.
|Aerosol exposure to the angola strain of marburg virus causes lethal viral hemorrhagic Fever in cynomolgus macaques. |
Alves DA, Glynn AR, Steele KE, Lackemeyer MG, Garza NL, Buck JG, Mech C, Reed DS
Vet Pathol 47 831-51. 2010
Cynomolgus macaques were exposed to the Angola strain of Lake Victoria Marburg virus (MARV) by aerosol to examine disease course and lethality. Macaques became febrile 4 to 7 days postexposure; the peak febrile response was delayed 1 to 2 days in animals that received a lower dose; viremia coincided with the onset of fever. All 6 macaques succumbed to the infection, with the 3 macaques in the low-dose group becoming moribund on day 9, a day later than the macaques in the high-dose group. Gross pathologic lesions included maculopapular cutaneous rash; pulmonary congestion and edema; pericardial effusion; enlarged, congested, and/or hemorrhagic lymphoid tissues; enlarged friable fatty liver; and pyloric and duodenal congestion and/or hemorrhage. Fibrinous interstitial pneumonia was the most consistent pulmonary change. Lymphocytolysis and lymphoid depletion, as confirmed by TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling), were observed in the mediastinal lymph nodes and spleen. MARV antigen was detected in the lungs, mediastinal lymph nodes, spleen, and liver of all animals examined. In infected macaques, nuclear expression of interleukin-33 was lost in pulmonary arteriolar and mediastinal lymph node high endothelial venule endothelial cells; interleukin-33-positive fibroblastic reticular cells in the mediastinal lymph node were consistently negative for MARV antigen. These macaques exhibited a number of features similar to those of human filovirus infections; as such, this model of aerosolized MARV-Angola might be useful in developing medical countermeasures under the Animal Rule.
|Knockdown of snail sensitizes pancreatic cancer cells to chemotherapeutic agents and irradiation. |
Kejun Zhang,Xuelong Jiao,Xiaoyi Liu,Bingyuan Zhang,Jigang Wang,Quan Wang,Yan Tao,Dianliang Zhang
International journal of molecular sciences 11 2010
The prognosis of patients with pancreatic cancer remains poor; only patients with small tumors and complete resection have a chance of a complete cure. Pancreatic cancer responds poorly to conventional therapies, including chemotherapy and irradiation. Snail is a transcription factor that has been associated with anti-apoptotic and chemoresistant properties in pancreatic cancer cells. In this study, we investigated whether knockdown of Snail suppresses growth of and/or sensitizes pancreatic cancer cells to chemotherapeutic agents and irradiation through induction of apoptosis. An adeno-associated virus vector was used to deliver Snail siRNA and knockdown Snail expression in untreated pancreatic cancer cells and in pancreatic cancer cells treated with chemotherapeutic agents or γ-irradiation. Our data indicate that our adeno-associated virus vector can efficiently deliver Snail siRNA into PANC-1 cells both in vitro and in vivo, resulting in the knockdown of Snail expression at the mRNA and protein levels. We further show that knockdown of Snail expression results in potent growth suppression of pancreatic cancer cells and suppresses xenograft tumor growth in vivo through induction of apoptosis. Finally, knockdown of Snail expression significantly sensitizes pancreatic cancer cells to chemotherapeutic agents and γ-irradiation through induction of apoptosis. In conclusion, our findings indicate that Snail is an important modulator of therapeutic responses of pancreatic cancer cells and is potentially useful as a sensitizer in pancreatic cancer therapy.Full Text Article
|Intermittent hypoxia promotes hippocampal neurogenesis and produces antidepressant-like effects in adult rats. |
Zhu XH, Yan HC, Zhang J, Qu HD, Qiu XS, Chen L, Li SJ, Cao X, Bean JC, Chen LH, Qin XH, Liu JH, Bai XC, Mei L, Gao TM
J Neurosci 30 12653-63. 2010
Increasing evidence indicates that stimulating hippocampal neurogenesis could provide novel avenues for the treatment of depression, and recent studies have shown that in vitro neurogenesis is enhanced by hypoxia. The aim of this study was to investigate the potential regulatory capacity of an intermittent hypobaric hypoxia (IH) regimen on hippocampal neurogenesis and its possible antidepressant-like effect. Here, we show that IH promotes the proliferation of endogenous neuroprogenitors leading to more newborn neurons in hippocampus in adult rats. Importantly, IH produces antidepressant-like effects in multiple animal models screening for antidepressant activity, including the forced swimming test, chronic mild stress paradigm, and novelty-suppressed feeding test. Hippocampal x-ray irradiation blocked both the neurogenic and behavioral effects of IH, indicating that IH likely produces antidepressant-like effects via promoting neurogenesis in adult hippocampus. Furthermore, IH stably enhanced the expression of BDNF in hippocampus; both the antidepressant-like effect and the enhancement of cell proliferation induced by IH were totally blocked by pharmacological and biological inhibition of BDNF-TrkB (tyrosine receptor kinase B) signaling, suggesting that the neurogenic and antidepressant-like effects of IH may involve BDNF signaling. These observations might contribute to both a better understanding of physiological responses to IH and to developing IH as a novel therapeutic approach for depression.
|Genotoxic and cytotoxic effects induced by aluminum in the lymphocytes of the common carp (Cyprinus carpio). |
García-Medina S, Razo-Estrada C, Galar-Martinez M, Cortéz-Barberena E, Gómez-Oliván LM, Alvarez-González I, Madrigal-Bujaidar E
Comp Biochem Physiol C Toxicol Pharmacol 2010
Few studies have been made in regard to the effect of aluminum on the molecular and cellular structure and function of aquatic organisms; therefore, in the present report we determined the genotoxic and cytotoxic effects induced by the metal on the lymphocytes of carp (Cyprinus carpio). Three groups of fish were exposed to 0.05, 120, and 239mg/L of aluminum (Al), respectively, by using Al(2) (SO(4))(3)·7H(2)O, and another group was included as control. The cells obtained were studied with the comet assay, flow cytometry, and the TUNEL method. With the first method we found a concentration and time dependent, significant increase in the amount of DNA damage induced by Al, and a higher damage when we evaluated the level of oxidized DNA. By applying flow cytometry we established that the metal induced a DNA content increase and ploidy modifications as well as apoptosis and disturbances of the cell cycle progression. With the last method we determined a significant increase in the amount of apoptotic cells, mainly in the 72-96h period. Our results established that Al caused deleterious DNA and cellular effects in the tested organism, and they suggested the pertinence of evaluating toxicity induced by the metal in organisms living in contaminated water bodies.
|REGgamma modulates p53 activity by regulating its cellular localization. |
Jian Liu,Guowu Yu,Yanyan Zhao,Dengpan Zhao,Ying Wang,Lu Wang,Jiang Liu,Lei Li,Yu Zeng,Yongyan Dang,Chuangui Wang,Guang Gao,Weiwen Long,David M Lonard,Shanlou Qiao,Ming-Jer Tsai,Bianhong Zhang,Honglin Luo,Xiaotao Li
Journal of cell science 123 2010
The proteasome activator REGγ mediates a shortcut for the destruction of intact mammalian proteins. The biological roles of REGγ and the underlying mechanisms are not fully understood. Here we provide evidence that REGγ regulates cellular distribution of p53 by facilitating its multiple monoubiquitylation and subsequent nuclear export and degradation. We also show that inhibition of p53 tetramerization by REGγ might further enhance cytoplasmic relocation of p53 and reduce active p53 in the nucleus. Furthermore, multiple monoubiquitylation of p53 enhances its physical interaction with HDM2 and probably facilitates subsequent polyubiquitylation of p53, suggesting that monoubiquitylation can act as a signal for p53 degradation. Depletion of REGγ sensitizes cells to stress-induced apoptosis, validating its crucial role in the control of apoptosis, probably through regulation of p53 function. Using a mouse xenograft model, we show that REGγ knockdown results in a significant reduction of tumor growth, suggesting an important role for REGγ in tumor development. Our study therefore demonstrates that REGγ-mediated inactivation of p53 is one of the mechanisms involved in cancer progression.Full Text Article
|Helicobacter pylori accelerates hepatic fibrosis by sensitizing transforming growth factor-beta1-induced inflammatory signaling. |
Ki MR, Goo MJ, Park JK, Hong IH, Ji AR, Han SY, You SY, Lee EM, Kim AY, Park SJ, Lee HJ, Kim SY, Jeong KS
Lab Invest 2010
Our earlier report has shown that Helicobacter pylori promoted hepatic fibrosis in a murine model. Herein, in order to elucidate the mechanism by which H. pylori accelerate liver fibrosis, the authors investigated the changes in expression levels of mitogen-activated protein kinases (MAPKs), p53-related proteins, antioxidants, and proinflammatory cytokines in liver samples. H. pylori infection enhanced CCl(4)-induced MAP kinase activation and p53 signaling pathway as well as Bax- and proliferating-cell nuclear antigen expressions, whereas H. pylori alone induced neither of these expressions nor hepatic fibrosis. Moreover, mRNA expressions of inflammatory cytokines, glutathione peroxidase expression, and the proliferative index were strongly augmented in livers of the H. pylori with CCl(4) treatment group compared with those of the CCl(4)-alone treatment group, whereas there was no difference in apoptotic index between the two groups. Interestingly, H. pylori treatment increased the number of alpha-fetoprotein-expressing hepatocytes independently of CCl(4) intoxication. In vitro analyses, using an immortalized rat hepatic stellate cell (HSC) line, revealed that H. pylori lysates increased the proliferation of HSCs, which was boosted by the addition of transforming growth factor-beta1 (TGF-beta1). Furthermore, the treatment of H. pylori lysates promoted the translocation of nuclear factor kappa-light-chain enhancer of activated B cells (NF-kappaB) into the nucleus based on an increase in the degradation of NF-kappaB inhibitor alpha, in the presence of TGF-beta1, as did H(2)O(2) treatment. In conclusion, H. pylori infection along with an elevated TGF-beta1 may accelerate hepatic fibrosis through increased TGF-beta1-induced pro-inflammatory signaling pathways in HSCs. Moreover, H. pylori infection might increase the risk of TGF-beta1-mediated tumorigenesis by disturbing the balance between apoptosis and proliferation of hepatocytes.Laboratory Investigation advance online publication, 7 June 2010; doi:10.1038/labinvest.2010.109 published online 7 June 2010.
|Neurokinin-1 receptor (NK1-R) expression in the brains of SIV-infected rhesus macaques: implications for substance P in NK1-R immune cell trafficking into the CNS. |
Vinet-Oliphant H, Alvarez X, Buza E, Borda JT, Mohan M, Aye PP, Tuluc F, Douglas SD, Lackner AA
Am J Pathol 177 1286-97. Epub 2010 Jul 29. 2010
Recent studies suggest a link between neuropsychiatric disorders and HIV/SIV infection. Most evidence indicates that monocytes/macrophages are the primary cell type infected within the CNS and that they contribute to CNS inflammation and neurological disease. Substance P (SP), a pleotropic neuropeptide implicated in inflammation, depression, and immune modulation via interaction with its cognate receptor, the neurokinin 1 receptor (NK1-R), is produced by monocyte/macrophages. While the presence of NK1-R on neurons is well known, its role on cells of the immune system such as monocyte/macrophages is just beginning to emerge. Therefore, we have examined the expression of SP and NK1-R and their relationship to SIV/HIV encephalitis (SIVE/HIVE) lesions and SIV-infected cells. These studies demonstrated intense expression of SP and NK1-R in SIVE lesions, with macrophages being the principal cell expressing NK1-R. Interestingly, all of the SIV-infected macrophages expressed NK1-R. Additionally, we examined the functional role of SP as a proinflammatory mediator of monocyte activation and chemotaxis. These studies demonstrated that treatment of monocytes with SP elicited changes in cell-surface expression for CCR5 and NK1-R in a dose-dependent manner. Moreover, pretreatment with SP enhanced both SP- and CCL5-mediated chemotaxis. All of these findings suggest that SP and NK1-R are important in SIV infection of macrophages and the development of SIVE lesions.Full Text Article
|Advancing cancer research: From hallmarks & biomarkers to tumor microenvironment progression|
|A Comparative Analysis of Human Embryonic Stem Cells Cultured in a Variety of Media Conditions|
|Comprehensive solutions for studying cell health - Life, death, and everything in between.|
|ApopTag® Peroxidase In Situ Apoptosis Detection Kit|