镍纹蛋白样β对脂多糖诱导心肌细胞损伤的抑制作用及其机制

Inhibitory effect of Metrnβ on lipopolysaccharide-induced cardiomyocyte injury and the mechanism

目的探讨镍纹蛋白样β(Metrnβ)对脂多糖(LPS)诱导心肌细胞损伤的抑制作用及其可能的机制。方法取对数生长期的H9c2心肌细胞,将其分为LPS组、Metrnβ组、Metrnβ+LPS组及对照组。LPS组、Metrnβ组、Metrnβ+LPS组分别给予1 mg/L LPS、200 ng/mL Metrnβ、1 mg/L LPS+200 ng/mL Metrnβ,对照组给予等体积PBS,作用12 h。采用MTT法检测细胞增殖情况,ELISA法检测乳酸脱氢酶(LDH)、炎症反应相关因子[肿瘤坏死因子α(TNF-α)、白细胞介素(IL)-1、IL-6]、氧化反应相关因子[活性氧(ROS)、丙二醛(MDA)、谷胱甘肽(GSH)]及抗铁死亡蛋白谷胱甘肽过氧化物酶4(Gpx4)表达,Western blotting法检测炎症信号分子Toll样受体4(TLR4)、Gpx4蛋白相对表达量,总铁比色法检测细胞游离铁(Fe^(2+))含量。结果与Metrnβ组、对照组比较,LPS组及Metrnβ+LPS组细胞LDH、TNF-α、IL-1β、IL-6、ROS、MDA表达均升高,细胞增殖率及GSH、Gpx4表达均降低,且LPS组变化更明显(P均<0.05)。与Metrnβ组、对照组比较,LPS组及Metrnβ+LPS组细胞Fe^(2+)含量升高、Gpx4蛋白相对表达量降低,且LPS组变化更明显(P均<0.05)。与Metrnβ组、对照组及Metrnβ+LPS组比较,LPS组TLR4蛋白相对表达量升高(P均<0.05)。结论Metrnβ可以减轻LPS引起的心肌细胞损伤,其机制可能与减轻细胞氧化应激反应、炎症反应及铁死亡有关。

Objective To investigate the inhibitory effect and mechanism of Metrnβon lipopolysaccharide-induced myocardial injury.Methods H9c2 cells in the logarithmic growth stage were divided into the LPS group,Metrnβgroup,Metrnβ+LPS group,and control group.Cells in the LPS group,Metrnβgroup and Metrnβ+LPS group were given 1 mg/L LPS,200 ng/mL Metrnβand 1 mg/L LPS+200 ng/mL Metrnβ,respectively,while cells in the control group were given equal volume of PBS for 12 h.Cell proliferation rate was detected by MTT assay.ELISA was used to detect lactate dehydro⁃genase(LDH),inflammatory response-related factors[tumor necrosis factor(TNF)-α,interleukin(IL)-1,and IL-6],ox⁃idative response-related factors[reactive oxygen species(ROS),malondialdehyde(MDA),and glutathione(GSH)]and anti-ferroptosis protein glutathione peroxidase 4(Gpx4).Western blotting was used to detect the Toll-like receptor 4(TLR4)and Gpx4 protein,and total iron colorimetry was used to detect the Fe^(2+)concentration of cells.Results Com⁃pared with the Metrnβgroup and control group,the expression levels of LDH,TNF-α,IL-1β,IL-6,ROS and MDA in⁃creased in the LPS group and Metrnβ+LPS group,and the cell proliferation rates and the expression levels of GSH and Gpx4 decreased,and the changes were more significant in the LPS group(all P<0.05).Compared with the Metrnβgroup and control group,the Fe^(2+)content of cells increased and the relative expression of Gpx4 protein decreased in the LPS group and Metrnβ+LPS group,and the changes were more significant in the LPS group(all P<0.05).Compared with the Metrnβgroup,control group and Metrnβ+LPS group,the relative expression level of TLR4 protein in the LPS group in⁃creased(P<0.05).Conclusion Metrnβalleviates LPS-induced injury in cardiomyocytes,which may be related to in⁃hibiting oxidative stress,inflammation,and ferroptosis.