RT Journal Article
SR Electronic
T1 Classification of brain pericytes based on cell structure, location, and α-smooth muscle actin content
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 114777
DO 10.1101/114777
A1 Roger I. Grant
A1 David A. Hartmann
A1 Robert G. Underly
A1 Andy Y. Shih
YR 2017
UL http://biorxiv.org/content/early/2017/03/08/114777.abstract
AB Smooth muscle cells and pericytes, together called mural cells, coordinate numerous vascular functions. Canonically, smooth muscle cells are ring-shaped and cover arterioles with circumferential processes, whereas pericytes extend thin processes that run longitudinally along capillaries. Nearly a century ago, Zimmerman described mural cells with mixed features of smooth muscle cells and pericytes, which he termed “transitional pericytes”. Recent studies suggest that transitional pericytes are critically positioned to regulate cerebral blood flow, but there remains considerable confusion on how to identify and categorize them. Here, we use metrics of cell morphology, vascular territory, and α-smooth muscle actin expression to test the hypothesis that transitional pericytes can be distinguished from canonical smooth muscle cells and pericytes. We first imaged fluorescently-labeled mural cells in large volumes of optically-cleared mouse cortex to elucidate the location of potential transitional pericytes. Subsequent investigation of isolated mural cells revealed that one type of transitional pericyte, which we called “ensheathing pericytes”, could be reliably distinguished. Ensheathing pericytes possessed protruding ovoid cell bodies and had elongated processes that encircled the vessel lumen. They were rich in α-smooth muscle actin and occupied proximal branches of penetrating arteriole offshoots. We provide guidelines to identify ensheathing pericytes and other mural cell types.FITCFluorescein isothiocyanateNG2Neural/glial antigen 2PDGFRβPlatelet-derived growth factor receptor βα-SMAα-smooth muscle actinSMCSmooth muscle cellEPEnsheathing pericyteMPMesh pericyteTSPThin-strand pericyte