title: Pericytes regulate vascular basement membrane remodeling and govern neutrophil extravasation during inflammation.
abstract: During inflammation polymorphonuclear neutrophils (PMNs) traverse venular walls, composed of the endothelium, pericyte sheath and vascular basement membrane. Compared to PMN transendothelial migration, little is known about how PMNs penetrate the latter barriers. Using mouse models and intravital microscopy, we show that migrating PMNs expand and use the low expression regions (LERs) of matrix proteins in the vascular basement membrane (BM) for their transmigration. Importantly, we demonstrate that this remodeling of LERs is accompanied by the opening of gaps between pericytes, a response that depends on PMN engagement with pericytes. Exploring how PMNs modulate pericyte behavior, we discovered that direct PMN-pericyte contacts induce relaxation rather than contraction of pericyte cytoskeletons, an unexpected response that is mediated by inhibition of the RhoA/ROCK signaling pathway in pericytes. Taking our in vitro results back into mouse models, we present evidence that pericyte relaxation contributes to the opening of the gaps between pericytes and to the enlargement of the LERs in the vascular BM, facilitating PMN extravasation. Our study demonstrates that pericytes can regulate PMN extravasation by controlling the size of pericyte gaps and thickness of LERs in venular walls. This raises the possibility that pericytes may be targeted in therapies aimed at regulating inflammation.
authors.affiliation: Lineberger Cancer Center, University of North Carolina, Chapel Hill, NC, USA. shijun_wang@med.unc.edu
authors.forename: Shijun
authors.initials: S
authors.lastname: Wang
authors.forename: Canhong
authors.initials: C
authors.lastname: Cao
authors.forename: Zhongming
authors.initials: Z
authors.lastname: Chen
authors.forename: Vytas
authors.initials: V
authors.lastname: Bankaitis
authors.forename: Eleni
authors.initials: E
authors.lastname: Tzima
authors.forename: Nader
authors.initials: N
authors.lastname: Sheibani
authors.forename: Keith
authors.initials: K
authors.lastname: Burridge
mesh_terms: D000205:Actomyosin / Q000378:metabolism; D000818:Animals; D001485:Basement Membrane / Q000378:metabolism*; D002450:Cell Communication; D002465:Cell Movement; D024141:Collagen Type IV / Q000378:metabolism; D007249:Inflammation / Q000378:metabolism*; D053583:Interleukin-1beta / Q000494:pharmacology; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D018375:Neutrophil Activation; D009504:Neutrophils / Q000378:metabolism*; D020286:Pericytes / Q000166:cytology / Q000378:metabolism*; D015398:Signal Transduction; D014680:Veins / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D054460:rho-Associated Kinases / Q000378:metabolism
chemical_list: D024141:Collagen Type IV; D053583:Interleukin-1beta; D000205:Actomyosin; D054460:rho-Associated Kinases