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Ca 2+ Dynamics and Contraction of Junctional Pericytes in the Retinal Vasculature
Author(s) -
Gonzales Albert,
Shui Bo,
Kotlikoff Michael,
Nelson Mark
Publication year - 2015
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.29.1_supplement.790.1
Subject(s) - pericyte , microbiology and biotechnology , retina , retinal , contraction (grammar) , anatomy , chemistry , confocal microscopy , biology , neuroscience , endothelial stem cell , endocrinology , in vitro , biochemistry
Pericytes, as part of neurovascular unit, are believed to contribute to the neuronal control of local capillary blood flow. It has been proposed that pericytes, similar to smooth muscle, may express the contractile machinery capable of generating focal constrictions within the capillary bed. The goal of the current study was to elucidate the functional role of pericytes localized at capillary bifurcations, and to test the overall hypothesis that these junctional pericytes are capable of controlling the direction of flow within the retinal vasculature. Using immunohistochemistry and fluorescent confocal microscopy of isolated mouse retina, we observed that only a subpopulation of pericytes proximal to the feeding pre‐capillary arterioles express contractile elements, such as α‐actin, Ca v 1.2, and TRPM4, and only these cells contracted to thromboxane A2 analog, U46619. Using a novel transgenic mouse genetically encoded for a Ca 2+ biosensor expressed in contractile pericytes (acta2 GCaMP5‐mCherry), we observed that junctional pericytes exhibited pharmacologically different Ca 2+ events when compared to non‐junctional pericytes. In addition, junctional pericytes localized proximal to the feeding arteriole preferentially constricted one branch of a capillary bifurcation, suggesting that pericytes may play a role in controlling the directional flow of blood. T32HL‐007594, HL‐044455, P01HL‐095488, R37DK‐053832, R01HL‐098243, Totman Medical Research Trust, and Fondation Leducq