Background. This study is aimed at investigating whether relaxin-3 exhibits protective effects against cardiomyopathy in diabetic rats by suppressing ERS. Methods. Eighty male SD rats were randomly divided into two groups: controls () and diabetes (). The streptozotocin-treated rats were randomly divided into three groups: diabetic group (DM), low-dose relaxin-3 group (0.2 μg/kg/d), and high-dose relaxin-3 group (2 μg/kg/d). The myocardial tissues and collagen fiber were observed by hematoxylin and eosin (H&E) and Masson staining. Serum brain natriuretic peptide (BNP), troponin (TNI), myoglobin, interleukin (IL-17), interleukin (IL)-1α, and tumor necrosis factor (TNF)-α were determined by ELISA. The protein expression of glucose regulatory protein 78 (GRP78) and C/EBP homologous protein (CHOP) in the heart tissue of each group was detected by Western blot analysis. Results. (1) HE and Masson staining indicated that relaxin-3 could attenuate myocardial lesions and myocardial collagen volume fraction. (2) BNP, TnI, and myoglobin in the DM group at four and eight weeks were significantly higher than in the controls (). The relaxin-3-treated groups showed significantly reduced serum BNP, TnI, and myoglobin levels compared with the DM group (). (3) IL-17, IL-1α, and TNF-α levels in the DM rats at 4 weeks were higher than in the controls (). Low or high dose of relaxin-3-treated groups showed reduced serum IL-17 and TNF-α levels compared with the DM group at four and eight weeks (). (4) CHOP and GRP78 protein expression was increased in the DM group at four and eight weeks compared with the controls (), and small and large doses of relaxin-3 significantly reduced GRP78 and CHOP protein expression. Conclusions. Exogenous relaxin-3 ameliorates diabetic cardiomyopathy by inhibiting ERS in diabetic rats.

中文翻译：

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Relaxin-3 通过抑制内质网应激改善糖尿病心肌病


背景。本研究旨在探讨relaxin-3 是否通过抑制 ERS ​​对糖尿病大鼠的心肌病发挥保护作用。方法。 80只雄性SD大鼠随机分为两组：对照组（ ）和糖尿病（ ）。将链脲佐菌素治疗的大鼠随机分为三组：糖尿病组（DM）、低剂量松弛素3组（ 0.2μg /kg/d）和高剂量松弛素3组（ 2μg /kg/d）。 d).通过苏木精和伊红(H&E)和Masson染色观察心肌组织和胶原纤维。采用ELISA法测定血清脑钠肽（BNP）、肌钙蛋白（TNI）、肌红蛋白、白细胞介素（IL-17）、白细胞介素（IL） -1α 、肿瘤坏死因子（TNF） -α 。采用Western blot分析检测各组心脏组织中葡萄糖调节蛋白78（GRP78）和C/EBP同源蛋白（CHOP）的蛋白表达量。结果。 (1)HE和Masson染色表明relaxin-3可以减轻心肌病变和心肌胶原体积分数。 (2) DM组第4周和第8周时的BNP、TnI和肌红蛋白显着高于对照组(）。与 DM 组相比，松弛素 3 治疗组的血清 BNP、TnI 和肌红蛋白水平显着降低（）。 (3) 4周时DM大鼠IL-17、IL- 1α和TNF- α水平高于对照组(）。与DM组相比，低或高剂量松弛素3治疗组在第4周和第8周时血清IL-17和TNF- α水平降低（）。 (4) 与对照组相比，DM 组在第 4 周和第 8 周时 CHOP 和 GRP78 蛋白表达增加（），小剂量和大剂量的relaxin-3显着降低GRP78和CHOP蛋白的表达。结论。外源性relaxin-3通过抑制糖尿病大鼠的ERS来改善糖尿病心肌病。