桑葚提取物对脂多糖诱导的心肌细胞炎症反应和细胞凋亡的影响

目的探讨桑葚提取物(ME)对脂多糖(LPS)致心肌细胞炎症反应和细胞凋亡的影响及分子机制。方法以正常培养的H9c2细胞作为对照组;用10 mg/L LPS处理的H9c2细胞作为LPS组;分别用50、100、200 mg/L的ME处理H9c2细胞,再用10 mg/L LPS处理,作为ME低、中、高浓度组。将si-NC、si-S100B转染至H9c2细胞中,再用10 mg/L LPS处理,作为LPS+si-NC组、LPS+si-S100B组;将pcDNA、pcDNA-S100B转染至H9c2细胞中,用200 mg/L ME处理,再用10 mg/L LPS处理,作为LPS+ME+pcDNA组、LPS+ME+pcDNA-S100B组。酶联免疫吸附法检测肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)水平;流式细胞术检测心肌细胞凋亡;Western blot检测Bcl-2、Bax、S100钙结合蛋白B(S100B)的蛋白表达;实时荧光定量PCR检测S100B mRNA表达水平。结果不同浓度ME处理的心肌细胞中TNF-α、IL-6的分泌水平降低,细胞凋亡率显著降低,Bcl-2表达水平显著升高,Bax和S100B表达水平均显著降低,且呈浓度依赖性。干扰S100B表达能抑制LPS诱导的心肌细胞炎症反应和细胞凋亡,S100B过表达则逆转了ME对LPS诱导的心肌细胞炎症反应和细胞凋亡的抑制作用。结论ME可抑制LPS诱导的心肌细胞炎症反应和细胞凋亡,其机制可能与下调S100B有关。

Effect of mulberry extract on cardiomyocyte inflammatory response and apoptosis induced by lipopolysaccharide

Aim To investigate the effect of mulberry extract(ME)on inflammatory response and apoptosis of cardiomyocytes induced by lipopolysaccharide(LPS)and its molecular mechanism.Methods H9c2 cells in normal culture were cultured as control group;H9c2 cells were treated with 10 mg/L LPS as LPS group;H9c2 cells were treated with 50,100 and 200 mg/L ME,and then treated with 10 mg/L LPS,as low,medium and high concentration ME groups.After transfection of si-NC and si-S100B into H9c2 cells,the cells were treated with 10 mg/L LPS,as LPS+si-NC group and LPS+si-S100B group.After transfection of pcDNA and pcDNA-S100B into H9c2 cells,the cells were treated with 200 mg/L ME followed by 10 mg/L LPS,as LPS+ME+pcDNA group and LPS+ME+pcDNA-S100B group.The levels of tumor necrosis factorα(TNF-α)and interleukin-6(IL-6)were detected by enzyme-linked immunosorbent assay.Flow cytometry was used to detect apoptosis;Western blot was used to detect the expressions of Bcl-2,Bax and S100 calcium binding protein B(S100B);Real-time quantitative PCR was used to detect the expression of S100B mRNA.Results The levels of TNF-αand IL-6 in cardiomyocytes treated with different concentrations of ME were significantly decreased,the apoptosis rate was significantly decreased,the expression of Bcl-2 was significantly increased,the expression of Bax was significantly decreased,and the expression of S100B was significantly decreased,with concentration-dependent manner(P<0.05).Interference of S100B expression inhibited LPS-induced inflammatory response and apoptosis of cardiomyocytes.Overexpression of S100B reversed the inhibitory effect of ME on LPS-induced inflammatory response and apoptosis of cardiomyocytes.Conclusion ME can inhibit LPS-induced inflammatory response and apoptosis of cardiomyocytes,and its mechanism may be related to the down-regulation of S100B.