|Short and long term fate of human AMSC subcutaneously injected in mice. |
López-Iglesias, P; Blázquez-Martínez, A; Fernández-Delgado, J; Regadera, J; Nistal, M; Miguel, MP
World journal of stem cells
To study the ability of human adipose-derived mesenchymal stem cells (AMSCs) to survive over the short and long term, their biodistribution and their biosafety in vivo in tumor-prone environments.We subcutaneously injected human AMSCs from different human donors into immunodeficient SCID mice over both short- (2 and 4 mo) and long- (17 mo) term in young, and aged tumor-prone mice. Presence of human cells was studied by immunohistochemistry and polymerase chain reaction analysis in all organs of injected mice.Subcutaneously injected AMSCs did not form teratomas at any time point. They did not migrate but remained at the site of injection regardless of animal age, and did not fuse with host cells in any organ examined. AMSCs survived in vivo for at least 17 mo after injection, and differentiated into fibroblasts of the subdermic connective tissue and into mature adipocytes of fat tissue, exclusively at the site of injection.Our results support the assertion that AMSC may be safe candidates for therapy when injected subcutaneously because of their long term inability to form teratomas.
|Human umbilical mesenchymal stem cells enhance the expression of neurotrophic factors and protect ataxic mice. |
Mei-Juan Zhang,Jia-Jia Sun,Lai Qian,Zhuo Liu,Zhuo Zhang,Wangsen Cao,Wei Li,Yun Xu
Cerebellar ataxias, which comprise a wide spectrum of progressive disorders, are incurable at present. It has been reported that human umbilical mesenchymal stem cell (HU-MSC) transplantation has a protective effect on neurodegenerative diseases. In this study, we investigated the effect of HU-MSCs on ataxic mice induced by cytosine beta-D-arabinofuranoside (Ara-C). The ataxic mouse received an intravenous injection of 2×10(6) HU-MSCs once a week for three consecutive weeks. Neurological function was scored weekly by rotarod test and open field test. The mouse cerebellar volume and weight were also measured. The apoptotic cells, pathological alternations and distribution of HU-MSCs were determined by TUNEL assay and immunohistochemistry staining respectively. Double immunostaining was carried out to investigate the dynamics of HU-MSCs in the host animals. Neurotrophic factors in cerebellar tissue and serum were measured by Q-PCR and ELISA. Our results showed that HU-MSCs implantation significantly improved the motor skills of ataxic mice 8 weeks after application. HU-MSCs also alleviated cerebellar atrophy and decreased the number of apoptotic cells in the therapeutic group. Implanted HU-MSCs stayed in cerebellum for at least three months with no obvious differentiation. HU-MSC treated mice had enhanced expression of insulin-like growth factor-1 (IGF-1) and vascular endothelial growth factor (VEGF) in cerebellum extraction and blood serum. Double immunostaining revealed that a few MAB1287 positive cells co-localized with IGF-1 or VEGF express cells. Our results suggest that HU-MSC treatment is capable of alleviating the motor impairments and cerebellar atrophy in the ataxic mouse model, probably via promoting particular neurotrophic factors.
|Genetically perpetuated human neural stem cells engraft and differentiate into the adult mammalian brain. |
Rubio, F J, et al.
Mol. Cell. Neurosci., 16: 1-13 (2000)
Human neural stem cells (HNSCs) may serve as a cellular vehicle for molecular therapies as well as for cell replacement in the human CNS. The survival, integration, and differentiation of HNSC.100, a multipotent cell line of HNSCs (A. Villa et al. (2000), Exp. Neurol. 161, 67-84), conditionally perpetuated by genetic and epigenetic means, was investigated after transplantation to the striatum and substantia nigra of the adult, intact rat brain. These are two key regions in the mammalian brain involved in the control of voluntary movement and motor coordination, among other functions. Soon after transplantation (1 week), the cells had already integrated in a nondisruptive manner into the surrounding tissue and migrated out of the implantation site to different distances depending on graft location (in the range of 0.5-2.5 mm). Cell migration was markedly more extensive in the striatum, where the cells colonized the whole extent of the caudate-putamen, than in the substantia nigra region. The engrafted cells completely downregulated the stem cell marker nestin and, due to their multipotential nature, differentiated and expressed mature neural markers. As expected from cells grafted into nonneurogenic regions of the intact brain, the majority of differentiated cells expressed GFAP (astroglia), but expression of other markers, like GalC (oligodendroglia) and MAP2, beta-tubulin III, NeuN, and NSE (for mature neurons) could also be detected. These results demonstrate that genetically perpetuated HNSCs, once transplanted, find residence in the host brain, where they differentiate, generating mature neural cells in the host, chimeric, adult mammalian brain. HNSCs cell lines may be a highly useful model for the development of humanized systems for cell replacement and/or gene transfer to the CNS, which will likely be strong candidates for future therapeutic application in human neurodegenerative conditions.
|Use of immunogold electron microscopy and monoclonal antibodies in the identification of nuclear substructures. |
Clevenger, C V and Epstein, A L
J. Histochem. Cytochem., 32: 757-65 (1984)
A cytochemical technique for the ultrastructural localization of unique nuclear antigens is reported. Using a post-embedding indirect immunogold labeling procedure, nuclear antigens in electron-dense regions of the nucleus are localized with a minimum of nonspecific staining. Using this technique and indirect immunofluorescence, a panel of antinuclear monoclonal antibodies is shown to recognize preferentially cell cycle-dependent nuclear substructures. The antigenic domains recognized include specific regions in condensed chromatin, interchromatin granules, euchromatin, and chromosomes. The specificity of antigen recognition is demonstrated with qualitative and quantitative immunogold electron microscopy and immunoblot analysis. These results reveal the existence of previously undefined supramolecular organization within the nucleus and demonstrate the utility of the immunogold procedure when monoclonal antibodies are used.