Shiyan dongwu yu bijiao yixue (Oct 2021)
CD137 Signaling Promotes Cardio-cerebral Angiogenesis in Mice Through Regulating Endothelial-mesenchymal Transition
Abstract
ObjectiveTo explore whether CD137-CD137L signaling can promote cardio-cerebral angiogenesis in atherosclerotic plaques via endothelium-mesenchymal transition (End-MT).MethodsMouse brain-derived endothelial cells (Bend.3) and aortas from male mice were divided into the following groups: control (10 ng/mL TNF-α), CD137-activated (10 ng/mL TNF-α + 5 mg/L CD137L agonist antibody), and CD137-inhibited (pretreated with 200 nmol/L IWR-1 for 30 min + 10 ng/mL TNF-α + 5 mg/L CD137L agonist antibody) groups. CD137L agonist antibody was used to activate CD137-CD137L signaling. Fluorescent quantitative PCR was used to determine the expression of CD31, vascular endothelial cadherin (VE-cadherin), fibroblast-specific protein-1F (FSP-1), Wnt, and α-smooth muscle actin (α-SMA) at the mRNA level. Western blotting was used to determine the expression of CD31, VE-cadherin, FSP-1, Wnt, and α-SMA at the protein level. A Transwell assay was used to observe the migration ability of endothelial cells. Matrigel tube formation ability of endothelial cells and mouse aortic ring angiogenesis assay were tested to detect the ability of angiogenesis.ResultsThe expressions of CD31 and VE-cadherin at the mRNA levels in endothelial cells were significantly lower in the CD137-activated group than those in the control group, while the expression was significantly downregulated in the CD137-inhibited group. The expressions of FSP-1, Wnt, and α-SMA were opposite (all P < 0.05). The expressions of CD31 and VE-cadherin proteins in endothelial cells were significantly higher in the CD137-activated group than those in the control group, while the expression was significantly downregulated in the CD137 inhibited group. The expressions of FSP-1, Wnt, and α-SMA were opposite (all P < 0.05). Migration cell number was markably higher in the CD137-activated group than that in the control group, while it was significantly lower in the CD137-inhibited group than that in the control group (P < 0.05). The values of the formation of the tube length (P < 0.05) and branch number (P < 0.05) were both significantly higher in the CD137-activated group than those in the control group, while these values were significantly lower in the CD137-inhibited group than those in the control group (P < 0.05). The number of microvessel outgrowths in the aortic rings was dramatically increased in the CD137-activated group than that in the control group, while it was reduced in the CD137-inhibited group (P < 0.05).ConclusionCD137-CD137L signaling can promote cardio-cerebral angiogenesis in atherosclerotic plaques by activating End-MT.
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