Activation of PI3Kγ/Akt pathway increases cardiomyocyte HMGB1 expression in diabetic environment.
Activation of PI3Kγ/Akt pathway increases cardiomyocyte HMGB1 expression in diabetic environment.
复制标题
糖尿病环境下 PI3K gamma/Akt 通路的激活增加心肌细胞 HMGB1 表达
DOI：
10.18632/oncotarget.13096
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发表时间：
2016-12-06
期刊：
影响因子：
--
通讯作者：
Rui T
中科院分区：
文献类型：
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作者：
Song J;Liu Q;Tang H;Tao A;Wang H;Kao R;Rui T
高迁移率族蛋白1（HMGB1）介导的心肌细胞-心脏成纤维细胞的相互作用，有助于诱导糖尿病（DM）心肌纤维化。在本研究中，我们的目的是研究细胞内信号通路，导致心肌细胞HMGB1的表达在糖尿病环境下。在高浓度葡萄糖（HG）条件化的心肌细胞中HMGB1表达增加。HG预处理心肌细胞后，PI3K γ和Akt的磷酸化水平明显升高。抑制PI3K γ（CRISPR/Cas9敲除质粒或AS605240）可阻止心肌细胞中HG诱导的Akt磷酸化和HMGB1表达。此外，抑制Akt（Akt1/2/3 siRNA或A6730）减弱了HG诱导的HMGB1产生。最后，用HG挑战心肌细胞导致活性氧（ROS）产生增加。用抗氧化剂（Mitotempo）处理心肌细胞可消除HG诱导的PI3K γ和Akt活化以及HMGB1的产生。分离的大鼠心肌细胞与高浓度的葡萄糖一起培养。Western blot法检测心肌细胞磷脂酰肌醇3-激酶γ（PI3K γ）和Akt活化。采用蛋白质印迹和酶联免疫吸附试验（ELISA）评估心肌细胞HMGB 1的产生，而采用DCFDA荧光探针测定心肌细胞氧化应激。我们的研究结果表明，心肌细胞在糖尿病条件下发生氧化应激，随后激活PI3K γ/Akt细胞信号通路，并进一步增加HMGB1的表达。
The high mobility group box 1 (HMGB1) protein mediates the cardiomyocyte–cardiac fibroblast interaction that contributes to induction of myocardial fibrosis in diabetes mellitus (DM). In the present study, we aim to investigate the intracellular signaling pathway that leads to cardiomyocyte HMGB1 expression under a diabetic environment. HMGB1 expression is increased in high concentration of glucose (HG)-conditioned cardiomyocytes. Challenging cardiomyocytes with HG also increased PI3Kγ and Akt phosphorylation. Inhibition of PI3Kγ (CRISPR/Cas9 knockout plasmid or AS605240) prevented HG-induced Akt phosphorylation and HMGB1 expression by the cardiomyocytes. In addition, inhibition of Akt (Akt1/2/3 siRNA or A6730) attenuated HG-induced HMGB1 production. Finally, challenging cardiomyocytes with HG resulted in increased reactive oxygen species (ROS) production. Treatment of cardiomyocytes with an antioxidant (Mitotempo) abolished HG-induced PI3Kγ and Akt activation, as well as HMGB1 production. Isolated rat cardiomyocytes were cultured with a high concentration of glucose. Cardiomyocyte phosphatidylinositol 3-kinase gamma (PI3Kγ) and Akt activation were determined by Western blot. Cardiomyocyte HMGB1 production was evaluated with Western blot and enzyme-linked immunosorbent assay (ELISA), while cardiomyocyte oxidative stress was determined with a DCFDA fluorescence probe. Our results suggest that the cardiomyocytes incur an oxidative stress under diabetic condition, which subsequently activates the PI3Kγ/Akt cell-signaling pathway and further increases HMGB1 expression.