title: The matrix protein CCN1 (CYR61) promotes proliferation, migration and tube formation of endothelial progenitor cells.
abstract: Neovascularization and re-endothelialization relies on circulating endothelial progenitor cells (EPCs), but their recruitment and angiogenic roles are subjected to regulation by the vascular microenvironment, which remains largely unknown. The present study was designed to investigate the effects of mature ECs and matrix protein CCN1 on the properties of EPCs. In a coculture system, effects of ECs on proliferation, migration and participation in tube-like formation of EPCs were evaluated, and functional assays were employed to identify the exact role of CCN1 in EPCs vitality and function. We demonstrated that ECs, as an indispensable part of the cellular milieu, significantly promoted the proliferation, migration and tube formation activities of EPCs, and more importantly, CCN1 was potentially involved in such effects of ECs. Expression of CCN1 in EPCs was significantly increased by serum, VEGF, ECs-cocultivation and ECs conditioned medium. Moreover, Ad-CCN1-mediated overexpression of CCN1 directly enhanced migration and tube formation of EPCs, whereas silencing of endogenous CCN1 in EPCs inhibits cell functions. Furthermore, CCN1 induced the expressions of chemokines and growth factors, such as MCP-1 and VEGF, suggesting a complex interaction between those proangiogenic factors. Our data suggest that matrix protein CCN1 may play an important role in microenvironment-mediated biological properties of EPCs.
authors.affiliation: Institute of Cardiovascular Diseases of PLA, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, People's Republic of China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yu
authors.forename: Yu
authors.initials: Y
authors.lastname: Gao
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
authors.forename: Lan
authors.initials: L
authors.lastname: Huang
authors.forename: Jun
authors.initials: J
authors.lastname: Qin
authors.forename: Ruiwei
authors.initials: R
authors.lastname: Guo
authors.forename: Mingbao
authors.initials: M
authors.lastname: Song
authors.forename: Shiyong
authors.initials: S
authors.lastname: Yu
authors.forename: Jianfei
authors.initials: J
authors.lastname: Chen
authors.forename: Bin
authors.initials: B
authors.lastname: Cui
authors.forename: Pan
authors.initials: P
authors.lastname: Gao