中文摘要：

目的探讨14-3-3γ基因在LPS预处理对抗心肌细胞缺氧/复氧（A/R）损伤中的作用。方法构建pSU-PER/14-3-3γRNA干扰重组质粒,转染入心肌细胞,分为5组：对照组、A/R组、LPS＋A/R组、pSUPER＋LPS＋A/R组、pSUPER/14-3-3γ＋LPS＋A/R组。Western blot检测14-3-3γ蛋白表达,生化自动分析仪测定乳酸脱氢酶（LDH）活性,MTT法测定细胞存活率,流式细胞仪检测细胞凋亡,线粒体肿胀实验检测线粒体通透性转换孔（mPTP）开放。结果 A/R损伤使细胞存活率下降,LDH升高,细胞凋亡增加,mPTP开放;LPS预处理可使14-3-3γ表达明显增加,通过抑制mPTP开放,对A/R损伤的细胞有保护作用;pSUPER/14-3-3γRNA干扰重组质粒通过抑制14-3-3γ蛋白表达,取消LPS预处理的保护作用。结论 LPS预处理可对抗心肌细胞缺氧/复氧损伤,其机制与上调14-3-3γ,从而抑制mPTP开放有关。

英文摘要：

Objective To explore the role of 14-3-3γ gene in the protection of cardiomyocytes with lipopolysaccharide（LPS） pretreatment against anoxia/reoxygenation（A/R） injury.Methods A RNA interference（RNAi） recombinant plasmid of pSUPER/14-3-3γ was constructed and transferred into cardiomyocytes.The cardiomyocytes were divided into five groups including a control group,an A/R group,a LPS＋A/R group,a pSUPER＋LPS＋A/R group and a pSUPER/14-3-3γ＋LPS＋A/R group.The protein level of 14-3-3γ was detected by Western blotting.The activity of lactate dehydrogenase（LDH） was determined by an automated biochemical analyzer.Cell viability was analyzed by MTT assay.Cell apoptosis was measured by flow cytometry.The opening of mitochondrial permeability transition pore（mPTP） was determined by swelling of isolated cardiac mitochondria.Results The A/R damage resulted in cell viability decrease,LDH and cell apoptosis increase,and mPTP opening.The LPS pretreatment up-regulated 14-3-3γ protein expression and protected cardiomyocytes against A/R injury through inhibiting the mPTP opening.The pSUPER/14-3-3γ RNAi recombinant plasmid could reduce 14-3-3γ protein expression and then reverse the protective effect of LPS pretreatment.Conclusion LPS pretreatment may have a protective effect on cardiomyocytes subjected to A/R injury,and its mechanism may be related to 14-3-3γ upregulation and subsequent mPTP opening inhibition.