Activating CD137 Signaling Promotes Sprouting Angiogenesis via Increased VEGFA Secretion and the VEGFR2/Akt/eNOS Pathway

Figure 2

Activation of CD137 with CD137L influences the expression of VEGFR2 and activates downstream Akt/eNOS. (a) The mRNA level of VEGFR2 by RT-PCR peaked at 3 hours after treatment with CD137L (10 μg/ml) at 0, 1, 3, 6, 12, and 24 hours, respectively. (b) The VEGFR2 expression measured by western blot, and protein relative level standardized by β-actin (c). (d) Phosphorylated VEGFR2 (p-VEGFR2, Tyr1173, murine) at 0, 2, 5, 10, 15, and 30 minutes, and the relative protein expression normalized by total VEGFR2 (e). (f) p-VEGFR2, p-AKT, and p-eNOS were detected by western blot under activating and blocking the CD137 signal for 10 minutes and standardized by total protein, , the CD137 agonist group compared with the control or anti-CD137 group (g). , .

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