Characterization of Smooth Muscle Cell and Pericyte Differentiation in the Rat Retina In Vivo

Abstract

This normative data and the identification of suitable in vivo markers of pericytes and SMCs will allow meaningful interpretation of the changes in these cell types. When examining the role of mural cells in developmental and pathologic vascularization, the results show that there is a need to use multiple-marker immunohistochemistry because of significant mural cell heterogeneity. The observation that the expression of caldesmon and calponin in arteriolar SMCs coincides with resistance to hyperoxia in the developing rat retina, lead us to suggest that maturation of SMCs and their consequent ability to regulate blood flow may play a key role in vessel stabilization.

Stromal Cell Identity Influences the In Vivo Functionality of Engineered Capillary Networks Formed by Co-delivery of Endothelial Cells and Stromal Cells

“…a-SMA has been widely used as a pericyte marker, 18 whereas calponin is a marker of mature smooth muscle. 38 IHC staining of human a-SMA revealed a broadly positive result for all of the implants containing a co-delivered stromal cell type, particularly at day 7 (Fig. 6A).…”

Hematopoietic Stem Cells Provide Repair Functions after Laser-Induced Bruch's Membrane Rupture Model of Choroidal Neovascularization

“…The limited number of GFP ϩ mural cells observed in the CNV lesion suggests that local events in the burn regulate HSC behavior and that the vessels that do form do not represent the endothelialpericyte relationship typically observed in normal vessels. 42 This is also the case for the astrocyte-endothelial relationship because significant lengths of the neovasculature lacked the astrocytic ensheathment, even though some of the neovasculature was ensheathed by HSCderived astrocytes. However, this study represents a single time point, and perhaps with later analysis, more typical vascular cell interactions will be observed.…”

“…38 Astrocytes are intimately associated with the vasculature during development of the mammalian retina 39 where astrocyte migration precedes the formation of patent vessels during normal development of the human retina. 40,41 Thus, ensheathment of the neovasculature by HSC-derived astrocytes should lead to improved barrier properties of the neovasculature after laser-induced CNV.…”

“…[45][46][47] Like von Willebrand factor, GS isolectin labels endothelial cells in culture. 48 This marker detects the smallest capillary and endothelial extensions, not always detectable by von Willebrand factor, 41,49 and does not label pericytes or astrocytes. 40,42,47,50 The response of the HSCs is clearly astrocytic rather than that of Mü ller cells; however, both cells have been intimately associated with the formation of glial vascular ensheathment in the retina.…”

“…53 Nevertheless, it is expressed only sporadically and at low levels by the capillaries of quiescent vasculature. 42 NG2 also labels a population of oligodendrocyte precursor cells in the rodent central nervous system. 54 However, because no cells of the oligodendrocytic lineage have been reported in the mouse retina or choroid, labeling of NG2 ϩ cells can be confirmed as being either of pericytes or smooth muscle cells.…”