Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, PR China.
Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi'an 710032, PR China.
Life Sci. 2019 Jun 1;226:22-32. doi: 10.1016/j.lfs.2019.03.049. Epub 2019 Mar 21.
Estrogen plays an important role in cardioprotection. Animal experiments showed that the G-protein coupled estrogen receptor 30 (GPR30) specific agonist G1 could reduce post-ischemic dysfunction and inhibit cardiac fibroblast proliferation. However, the underlying mechanism of action is not clear. The current study tests the hypothesis that GPR30 reduces myocardial infarct area and fibrosis in female ovariectomized (OVX) mice by activating the PI3K/AKT pathway.
In this study, we established a myocardial infarction (MI) animal model derived from OVX C57BL/6 female mice, and investigated the effect of G1 on cardiac function by echocardiography and Hemodynamics, morphology and expression of fibrosis-related and apoptosis-related proteins by Masson's trichrome and H&E, Immunofluorescence, Western blotting and TUNEL.
Combination with OVX significantly increased myocardial fibrosis and MI area compared to MI treatment alone, as determined by echocardiography and hemodynamics. Further addition of G1 changed the expression of apoptosis-related proteins, decreased the levels of tumor necrosis factor-α and interleukin-10, and reduced the degree of myocardial fibrosis and myocardial infarct area. Primary cultured cardiac fibroblasts (CFs) were subjected to hypoxia/serum deprivation (H/SD) simulating the in vivo ischemia model. When the PI3K/AKT pathway was inhibited by wortmanin in H/SD CFs, G1 failed to induce significant changes in the expression of apoptosis-related proteins.
It suggested that GPR30 may improve cardiac function in female OVX mice by activating the PI3K/AKT pathway and reducing myocardial infarct size and fibrosis.
雌激素在心脏保护中起着重要作用。动物实验表明，G 蛋白偶联雌激素受体 30（GPR30）特异性激动剂 G1 可减少缺血后功能障碍并抑制心肌成纤维细胞增殖。然而，其作用机制尚不清楚。本研究通过激活 PI3K/AKT 通路，检验 GPR30 通过激活 PI3K/AKT 通路减少去卵巢（OVX）雌性小鼠心肌梗死面积和纤维化的假设。
本研究通过建立来源于 OVX C57BL/6 雌性小鼠的心肌梗死（MI）动物模型，通过超声心动图和血流动力学、Masson 三色和 H&E、免疫荧光、Western blot 和 TUNEL 检测纤维化相关和凋亡相关蛋白的形态和表达，研究 G1 对心脏功能的影响。
与单独 MI 处理相比，OVX 联合明显增加了心肌纤维化和 MI 面积，这可通过超声心动图和血流动力学来确定。进一步添加 G1 改变了凋亡相关蛋白的表达，降低了肿瘤坏死因子-α和白细胞介素-10 的水平，并减少了心肌纤维化和心肌梗死面积。原代培养的心肌成纤维细胞（CFs）进行缺氧/血清剥夺（H/SD）模拟体内缺血模型。当 H/SD CFs 中的 PI3K/AKT 通路被wortmanin 抑制时，G1 未能诱导凋亡相关蛋白的表达发生显著变化。
这表明 GPR30 可能通过激活 PI3K/AKT 通路，减少心肌梗死面积和纤维化，改善雌性 OVX 小鼠的心脏功能。
