Peng Jia-Yu, Fu Xiao, Luo Xue-Yang, Liu Fang, Zhang Bing, Zhou Bin, Sun Kun, Chen Alex F
Institute for Developmental and Regenerative Cardiovascular Medicine, Xin Hua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Department of Pediatric Cardiology, Xin Hua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Department of Child Healthcare, The International Peace Maternity & Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
Institute for Developmental and Regenerative Cardiovascular Medicine, Xin Hua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
Transl Res. 2024 Aug;270:13-23. doi: 10.1016/j.trsl.2024.03.011. Epub 2024 Mar 26.
Post-ischemic angiogenesis is critical for perfusion recovery and tissue repair. ELABELA (ELA) plays an essential role in embryonic heart development and vasculogenesis. However, the mechanism of ELA on post-ischemic angiogenesis is poorly characterized.
We first assessed ELA expression after hind limb ischemia (HLI) in mice. We then established a HLI model in tamoxifen-inducible endothelial-ELA-specific knockout mice (ELA) and assessed the rate of perfusion recovery, capillary density, and VEGFR2 pathway. Knockdown of ELA with lentivirus or siRNA and exogenous addition of ELA peptides were employed to analyze the effects of ELA on angiogenic capacity and VEGFR2 pathway in endothelial cells in vitro. The serum levels of ELA in healthy people and patients with type 2 diabetes mellitus (T2DM) and diabetic foot ulcer (DFU) were detected by a commercial ELISA kit.
In murine HLI models, ELA was significantly up-regulated in the ischemic hindlimb. Endothelial-specific deletion of ELA impaired perfusion recovery and angiogenesis. In physiologic conditions, no significant difference in VEGFR2 expression was found between ELA mice and ELA mice. After ischemia, the expression of VEGFR2, p-VEGFR2, and p-AKT was significantly lower in ELA mice than in ELA mice. In cellular experiments, the knockdown of ELA inhibited endothelial cell proliferation and tube formation, and the addition of ELA peptides promoted proliferation and tube formation. Mechanistically, ELA upregulated the expression of VEGFR2, p-VEGFR2, and p-AKT in endothelial cells under hypoxic conditions. In clinical investigations, DFU patients had significantly lower serum levels of ELA compared to T2DM patients.
Our results indicated that endothelial ELA is a positive regulator of post-ischemic angiogenesis via upregulating VEGFR2 expression. Targeting ELA may be a potential therapeutic option for peripheral arterial diseases.
缺血后血管生成对于灌注恢复和组织修复至关重要。ELABELA（ELA）在胚胎心脏发育和血管生成中起重要作用。然而，ELA在缺血后血管生成中的机制尚不清楚。
我们首先评估了小鼠后肢缺血（HLI）后ELA的表达。然后我们在他莫昔芬诱导的内皮细胞ELA特异性敲除小鼠（ELA）中建立了HLI模型，并评估了灌注恢复率、毛细血管密度和VEGFR2通路。采用慢病毒或小干扰RNA敲低ELA以及外源性添加ELA肽来分析ELA对体外内皮细胞血管生成能力和VEGFR2通路的影响。使用商用ELISA试剂盒检测健康人、2型糖尿病（T2DM）患者和糖尿病足溃疡（DFU）患者血清中ELA的水平。
在小鼠HLI模型中，缺血后肢中ELA显著上调。内皮细胞特异性缺失ELA会损害灌注恢复和血管生成。在生理条件下，ELA小鼠和ELA小鼠之间VEGFR-2表达无显著差异。缺血后，ELA小鼠中VEGFR2、p-VEGFR2和p-AKT的表达明显低于ELA小鼠。在细胞实验中，敲低ELA会抑制内皮细胞增殖和管腔形成，而添加ELA肽则促进增殖和管腔形成。机制上，ELA在缺氧条件下上调内皮细胞中VEGFR2、p-VEGFR2和p-AKT的表达。在临床研究中，与T2DM患者相比，DFU患者血清中ELA水平显著降低。
我们的结果表明，内皮细胞ELA通过上调VEGFR2表达是缺血后血管生成的正调节因子。靶向ELA可能是外周动脉疾病的一种潜在治疗选择。
