Center for Clinical and Translational Research, The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205, USA.
J Cell Mol Med. 2011 May;15(5):1087-95. doi: 10.1111/j.1582-4934.2010.01072.x. Epub 2010 Apr 19.
Production of connective tissue growth factor (CCN2, also known as CTGF) is a hallmark of hepatic fibrosis. This study examined early primary cultures of hepatic stellate cells (HSC) for (i) CCN2 regulation of its cognate receptor integrin subunits; and (ii) interactions between CCN2 and integrin α(5)β(1), heparan sulphate proteoglycans (HSPG) or fibronectin (FN) in supporting cell adhesion. HSC were isolated from healthy male Balb/c mice. mRNA levels of CCN2 or α(5), β(1), αv or β(3) integrin subunits were measured in days 1-7 primary culture HSC, and day 3 or day 7 cells treated with recombinant CCN2 or CCN2 small interfering RNA. Interactions between CCN2 and integrin α(5)β(1), HSPG or FN were investigated using an in vitro cell adhesion assay. Co-incident with autonomous activation over the first 7 days, primary culture HSC increasingly expressed mRNA for CCN2 or integrin subunits. Addition of exogenous CCN2 or knockdown of endogenous CCN2 differentially regulated integrin gene expression in day 3 versus day 7 cells. Either full length CCN2 ('CCN2(1-4)') or residues 247-349 containing module 4 alone ('CCN2(4)') supported day 3 cell adhesion in an integrin α(5)β(1) - and HSPG-dependent fashion. Adhesion of day 3 cells to FN was promoted in an integrin α(5) β(1)-dependent manner by CCN2(1-4) or CCN2(4), whereas FN promoted HSPG-dependent HSC adhesion to CCN2(1-4) or CCN2(4). These findings suggest CCN2 regulates integrin expression in primary culture HSC and supports HSC adhesion via its binding of cell surface integrin α(5)β(1), a novel CCN2 receptor in primary culture HSC which interacts co-operatively with HSPG or FN.
结缔组织生长因子（CCN2，也称为 CTGF）的产生是肝纤维化的一个标志。本研究在原代培养的肝星状细胞（HSC）中检测了（i）CCN2 对其同源受体整合素亚基的调节；（ii）CCN2 与整合素 α(5)β(1)、硫酸乙酰肝素蛋白聚糖（HSPG）或纤维连接蛋白（FN）在支持细胞黏附中的相互作用。HSC 从健康雄性 Balb/c 小鼠中分离出来。在第 1-7 天的原代培养 HSC 中测量 CCN2 或 α(5)、β(1)、αv 或 β(3)整合素亚基的 mRNA 水平，并在第 3 天或第 7 天用重组 CCN2 或 CCN2 小干扰 RNA 处理细胞。使用体外细胞黏附测定法研究 CCN2 与整合素 α(5)β(1)、HSPG 或 FN 之间的相互作用。在最初的 7 天内，与自主激活一致，原代培养 HSC 逐渐表达 CCN2 或整合素亚基的 mRNA。外源性 CCN2 的添加或内源性 CCN2 的敲低在第 3 天和第 7 天的细胞中以不同的方式调节整合素基因表达。全长 CCN2（'CCN2(1-4)）或仅含有模块 4 的残基 247-349（'CCN2(4)）以整合素 α(5)β(1)和 HSPG 依赖的方式支持第 3 天的细胞黏附。FN 以整合素 α(5)β(1)依赖的方式促进第 3 天细胞与 CCN2(1-4)或 CCN2(4)的黏附，而 FN 促进 HSPG 依赖的 HSC 与 CCN2(1-4)或 CCN2(4)的黏附。这些发现表明 CCN2 在原代培养的 HSC 中调节整合素表达，并通过其与细胞表面整合素 α(5)β(1)的结合支持 HSC 黏附，这是原代培养的 HSC 中的一种新型 CCN2 受体，与 HSPG 或 FN 协同相互作用。
