|Embryonic rat vascular smooth muscle cells revisited - a model for neonatal, neointimal SMC or differentiated vascular stem cells? |
Kennedy, E; Hakimjavadi, R; Greene, C; Mooney, CJ; Fitzpatrick, E; Collins, LE; Loscher, CE; Guha, S; Morrow, D; Redmond, EM; Cahill, PA
The A10 and A7r5 cell lines derived from the thoracic aorta of embryonic rat are widely used as models of non-differentiated, neonatal and neointimal vascular smooth muscle cells in culture. The recent discovery of resident multipotent vascular stem cells within the vessel wall has necessitated the identity and origin of these vascular cells be revisited. In this context, we examined A10 and A7r5 cell lines to establish the similarities and differences between these cell lines and multipotent vascular stem cells isolated from adult rat aortas by determining their differentiation state, stem cell marker expression and their multipotency potential in vitro.Vascular smooth muscle cell differentiation markers (alpha-actin, myosin heavy chain, calponin) and stem cell marker expression (Sox10, Sox17 and S100β) were assessed using immunocytochemistry, confocal microscopy, FACS analysis and real-time quantitative PCR.Both A10 and A7r5 expressed vascular smooth muscle differentiation, markers, smooth muscle alpha - actin, smooth muscle myosin heavy chain and calponin. In parallel analysis, multipotent vascular stem cells isolated from rat aortic explants were immunocytochemically myosin heavy chain negative but positive for the neural stem cell markers Sox10+, a neural crest marker, Sox17+ the endoderm marker, and the glia marker, S100β+. This multipotent vascular stem cell marker profile was detected in both embryonic vascular cell lines in addition to the adventitial progenitor stem cell marker, stem cell antigen-1, Sca1+. Serum deprivation resulted in a significant increase in stem cell and smooth muscle cell differentiation marker expression, when compared to serum treated cells. Both cell types exhibited weak multipotency following adipocyte inductive stimulation. Moreover, Notch signaling blockade following γ-secretase inhibition with DAPT enhanced the expression of both vascular smooth muscle and stem cell markers.We conclude that A10 and A7r5 cells share similar neural stem cell markers to both multipotent vascular stem cells and adventitial progenitors that are indicative of neointimal stem-derived smooth muscle cells. This may have important implications for their use in examining vascular contractile and proliferative phenotypes in vitro.
|Chronic-pain-associated astrocytic reaction in the spinal cord dorsal horn of human immunodeficiency virus-infected patients. |
Shi, Y; Gelman, BB; Lisinicchia, JG; Tang, SJ
The Journal of neuroscience : the official journal of the Society for Neuroscience
Studies with animal models have suggested that reaction of glia, including microglia and astrocytes, critically contributes to the development and maintenance of chronic pain. However, the involvement of glial reaction in human chronic pain is unclear. We performed analyses to compare the glial reaction profiles in the spinal dorsal horn (SDH) from three cohorts of sex- and age-matched human postmortem tissues: (1) HIV-negative patients, (2) HIV-positive patients without chronic pain, and (3) HIV patients with chronic pain. Our results indicate that the expression levels of CD11b and Iba1, commonly used for labeling microglial cells, did not differ in the three patient groups. However, GFAP and S100β, often used for labeling astrocytes, were specifically upregulated in the SDH of the "pain-positive" HIV patients but not in the "pain-negative" HIV patients. In addition, proinflammatory cytokines, TNFα and IL-1β, were specifically increased in the SDH of pain-positive HIV patients. Furthermore, proteins in the MAPK signaling pathway, including pERK, pCREB and c-Fos, were also upregulated in the SDH of pain-positive HIV patients. Our findings suggest that reaction of astrocytes in the SDH may play a role during the maintenance phase of HIV-associated chronic pain.