基于Ang1/Tie2 信号通路研究周细胞调控 腹膜血管新生的作用机制.

AIM: To examine the mechanism by which pericytes regulate peritoneal angiogenesis by observing the interaction between vascular pericytes and vascular endothelial cells. METHODS: Transforming growth factor-β1 （TGF-β1） was used to treat human microvascular pericytes（ HMPCs） for 24, 48 and 96 h, and the expression levels of angiopoietin 1（ Ang1） in HMPCs was detected by Western blot. The supernatant of TGF-β1-treated HMPCs was collected as conditioned medium （T-HMPC-CM）, and human peritoneal vascular endothelial cells （HPVECs） were treated with THMPC-CM to construct an indirect co-culture model. HMPCs were treated with TGF-β1 and seeded with HPVECs on matrigel to construct a direct co-culture model. The HMPCs without TGF-β1 treatment served as the negative control group, the Ang1-treated HPVECs served as the positive control group, and the Tie2 inhibitor-treated HPVECs served as the inhibitor group. The proliferation, migration and angiogenesis of HPVECs were detected by CCK-8 assay, wound healing assay, Transwell assay and Tube formation assay, and the co-localization of HPVECs and HMPCs was observed by cell membrane fluorescence probe staining. Total and phosphorylated Tie2 protein levels were detected by Western blot. RESULTS: The expression level of Ang1 in HMPCs was increased significantly after treated with TGF-β1 for 96 h. Compared with negative control group, T-HMPC-CM inhibited the migration and angiogenesis of HPVECs, and Tie2 was phosphorylated to stabilize the vascular state, which was similar to the effect of exogenous Ang1. After blocking the Ang1/Tie2 signaling pathway with a Tie2 inhibitor, these phenomena were reversed to some extent. CONCLUSION: The secretion of Ang1 in HMPCs is stimulated by TGF-β1, which activates the Tie2 signaling pathway in HPVECs, and then inhibits angiogenesis of HPVECs, thus maintaining peritoneal vascular stability. [ABSTRACT FROM AUTHOR]