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Aged Microvascular Networks Display Increased Pericyte Coverage along Capillaries
Author(s) -
SuarezMartinez Ariana Diandra,
Lane James Hayden,
Murfee Walter Lee
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.830.1
Subject(s) - pericyte , angiogenesis , mural cell , sprouting angiogenesis , biology , microvessel , blood vessel , sprouting , endothelial stem cell , microbiology and biotechnology , pathology , neovascularization , endocrinology , medicine , cancer research , in vitro , genetics , botany
While a common characteristic of aging is impaired angiogenesis, defined as the sprouting of capillaries from existing blood vessels, the altered mechanisms remain understudied. An opportunity exists to identify potential mechanisms by comparing cellular characteristics of aged versus adult microvascular networks. A critical cell type involved in capillary sprouting is the vascular pericyte with pericyte‐endothelial cell interactions playing both vessel stabilization (anti‐angiogenic) and angiogenic roles. However, little is known regarding whether pericyte presence is altered in aged tissues. The objective of this study was to compare pericyte coverage along capillaries in adult and aged microvascular networks. Mesentery tissues from adult (9 months) and aged (24 months) male Fischer 344 rats were harvested and immunohistochemically labeled for platelet endothelial cell adhesion molecule (PECAM), and pericyte markers, α‐smooth muscle actin (α‐SMA) or neuron‐glial antigen 2 (NG2). PECAM labeling identified endothelial cells along arterioles, venules, and capillaries across the hierarchy of networks. The percentage of capillaries (diameter <7 mm) with observable SMA positive pericyte labelling in aged networks was significantly increased compared to adult networks (Aged = 90.9% vs. Adult = 78.1%; p<0.05). Similarly, NG2 coverage of capillaries was also significantly increased in aged networks compared to adult networks (Aged = 94.9% vs. Adult = 76.6%; p<0.005). These results suggest that aged microvascular networks are characterized by increased pericyte coverage and motivate a new hypothesis for aging research that impaired angiogenesis in aged tissues is associated with increased vessel stabilization by vascular pericytes. Support or Funding Information NIH R01AG049821, NIH P20GM103629