动物造模 z-bio 2022-03-04 221

　　Objective To investigate whether CD137-CD137L signal (CD137 signal for short) promotes cardio-cerebral angiogenesis by regulating endothelial cell-mesenchymal transition.

　　Methods The mouse brain microvascular endothelial cells (bEnd.3) or mouse thoracic aortic rings were divided into 3 groups, namely the control group [10 ng/mL tumor necrosis factor-α (TNF-α) ], CD137 stimulation group (10 ng/mL TNF-α and 5 mg/L CD137L agonistic antibody) and CD137 inhibition group (200 nmol/L IWR-1 pretreated cells for 30 min, then added 10 ng/L mL of TNF-α and 5 mg/L of CD137L agonistic antibody) to stimulate CD137 signaling with CD137L recombinant protein. Fluorescence quantitative PCR and Western blotting were used to detect CD31, vascular endothelial cadherin (VE-Cadherin), actin α (α-smooth muscle actin, α-SMA), The expression of fibroblast specific protein-1 (FSP-1) and Wnt protein; Transwell migration assay was used to detect the number of transmembrane cells, and cell migration ability was compared; endothelial cell lumen formation assay was used to detect the mice in each group Lumen-forming capacity of brain microvascular endothelial cells. The arterial ring angiogenesis experiment was used to detect the formation ability of new microvessels in the thoracic aortic ring of mice in each group.

　　Results The expression levels of CD31, VE-Cadherin mRNA and protein in the CD137-stimulated mouse brain microvascular endothelial cells were lower than those in the control group (P<0.05), and the mRNA and protein expression levels of FSP-1, Wnt and α-SMA were higher than those in the control group (P<0.05). Control group (P＜0.05); CD31, VE-Cadherin mRNA and protein expression levels in CD137 inhibition group were higher than those in CD137 stimulation group (P＜0.05), FSP-1, Wnt and α-SMA mRNA and protein expression levels were lower compared with the CD137 stimulation group (P<0.05). The number of migrating cerebral microvascular endothelial cells in the CD137-stimulated group was more than that in the control group (P<0.05), and the number of cells in the CD137-inhibited group was less than that in the CD137-stimulated group (P<0.05). The length and number of branches of cerebral microvascular endothelial cells in the CD137-stimulated group were greater than those in the control group (P＜0.05). The number of new microvessels in the thoracic aortic ring of mice in the CD137 stimulation group was more than that in the control group (P<0.05).

　　Conclusion CD137 signaling may promote angiogenesis in mice by regulating End-MT.