Klotho对脂多糖所致心肌损伤的作用及机制

Effect of Klotho on LPS-induced cardiomyocyte damage and its mechanism

目的探讨Klotho对脂多糖(LPS)所致心肌损伤的影响及相关作用机制。方法以大鼠胚胎H9c2心肌细胞系为研究对象,经不同浓度Klotho预处理后,加1 g/L LPS处理6 h,检测细胞培养液中乳酸脱氢酶(LDH)含量及细胞存活率来反映心肌细胞损伤。检测细胞培养液中肿瘤坏死因子α(TNF-α)、白细胞介素β(IL-β)和白细胞介素6(IL-6)的含量来反映心肌细胞的炎症反应。检测细胞中丙二醛(MDA)的含量以及超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)的活性来反映细胞氧化应激水平。流式细胞术检测细胞凋亡情况。Western blot检测核因子κB(NF-κB)p65和p-NF-κB p65的蛋白表达水平。结果 Klotho预处理可显著抑制LPS所致的心肌细胞存活率下降,抑制LDH、TNF-α、IL-β、IL-6释放,下调MDA的含量,升高SOD、GSH-Px的活性,抑制细胞凋亡,抑制p-NF-κB p65的蛋白表达(P<0.05)。结论 Klotho可抑制LPS所致的心肌细胞损伤,其作用机制可能与抑制NF-κB信号通路的活化,进而发挥抗炎、抗氧化应激,同时抑制细胞凋亡有关。

Aim To investigate the effect and mechanism of Klotho on lipopolysaccharide （LPS） induced cardio-myocyte damage. Methods H9c2 cells were pretreated with different concentrations of Klotho protein, then treated with 1 g/L LPS for 6 hours, and cardiomyocyte damage was estimated by detecting the content of lactate dehydrogenase （LDH） and cell viability. Inflammation was estimated by detecting the content of tumor necrosis factor-α （TNF-α）, interleukin-13（IL-β）, IL-6. The status of oxidative stress was measured by malondialdehyde （ MDA）, superoxide dismutase （SOD）, glutathione peroxidase （GSH-Px）. Cell apoptosis was measured with flow cytometry. The expression of nuclear factor-κB （NF-KB）p65 and p-NF-κB p65 at protein levels were measured with Western blot assay. Results K]otho can alleviate LPS-induced decrease of cell viability, inhibit the release of LDH, TNF-α, IL-β, IL-6, down-regulate the content of MDA, enhance the activity of SOD, GSH-Px, suppress cell apoptosis and p-NF-κB p65 protein expression （P〈 0.05 ）. Conclusion Klotho can alleviate LPS-induced cardiomyocyte damage. And its mechanism may be related to the downregulation of NF-κB activation, and protect H9c2 cells from LPS-induced inflammation, oxidative stress and cell apoptosis.