中文摘要：

目的 探讨脾酪氨酸激酶（Syk）对高糖诱导的H9c2心肌细胞凋亡的影响及其机制.方法 将体外培养的H9c2心肌细胞分为5组：对照组（5.5 mmol/L葡萄糖,NG组）、高糖组（33 mmol/L葡萄糖,HG组）、Syk抑制剂对照组（5.5 mmol/L葡萄糖＋1μmol/L BAY,NG＋ BAY组）、Syk抑制剂高糖组（33 mmol/L葡萄糖＋1μmol/L BAY,HG＋ BAY组）、甘露醇高渗透压对照组（5.5 mmol/L葡萄糖＋27.5 mmol/L甘露醇,OC组）.采用Western印迹方法检测磷酸化Syk（p-Syk）、cleaved-caspase-1及Bax、Bcl-2的蛋白水平;逆转录PCR检测caspase-1、Bax、Bcl-2 mRNA的表达;流式细胞仪检测H9c2心肌细胞凋亡率;MTT比色法检测细胞活力.结果 与NG组相比,HG组H9c2心肌细胞活力下降（F=37.3,P〈0.05）、凋亡率增加（F=46.5,P〈0.05）,OC组、NG＋ BAY组细胞凋亡率与细胞活力差异均无统计学意义（P均〉0.05）;且HG组p-Syk、cleaved-caspase-1及Bax表达增加,Bcl-2表达降低（F=8.4、80.5、7.6、37.4,P均〉0.05）,caspase-1及Bax mRNA表达升高,Bcl-2 mRNA表达降低（F=130.7、17.8、7.18,P均〉0.05）;与HG组相比,HG＋ BAY组细胞活力升高（F=37.3,P 〉0.05）、细胞凋亡率降低（F=46.5,P〈0.05）,且cleaved-caspase-1及Bax表达降低,Bcl-2表达水平升高（F =80.5、7.6、37.4,P均〉0.05）,caspase-1及Bax mRNA表达降低,Bcl-2 mRNA表达升高（F=130.7、17.8、7.18,P均〉0.05）.结论 在高糖条件下,Syk可诱导心肌细胞凋亡,其作用是通过调控Bax、Bcl-2的表达.

英文摘要：

Objective To study the effects of spleen tyrosine kinase （Syk） on high glucose-induced apoptosis of H9c2 myocardial cells and its mechanism.Methods The cultured H9c2 myocardial cells were divided into 5 groups： control group （5.5 mmol/L glucose, NG group）, high glucose group （33 mmol/L glucose, HG group）, Syk inhibitor with normal glucose group （5.5 mmol/L glucose ＋ 1 μmol/L BAY, NG ＋BAY group）, Syk inhibitor with high glucose group （33 mmol/L glucose ＋ 1 μmol/L BAY, HG ＋ BAY group） and osomotic control group （5.5 mmol/L glucose ＋ 27.5 mmol/L mannose, OC group）.The protein levels of phospho-Syk,cleaved-caspase-1, Bax, Bcl-2 were measured by Western blotting.The mRNA levels of caspase-1, Bax, Bcl-2 were measured by reverse transcription PCR.Apoptosis of H9c2 myocardial cells was detected by flow cytometry.The cell viability were detected by MTT colorimetry.Results Compared with NG group, the viability of H9c2 myocardial cells was decreased （F =37.3, P 〈 0.05） and the apoptosis rate was increased （F =46.5, P 〈 0.05） in HG group.The apoptosis rate and viability in OC group and NG ＋ BAY group were not different （all P 〉0.05）.Moreover, the protein levels of p-Syk, cleaved-caspase-1,Bax were increased while the level of Bcl-2 was decreased in HG group （F =8.4, 80.5, 7.6, 37.4, all P 〈0.05）.The level of caspase-1, Bax mRNA were increased while the Bcl-2 mRNA was decreased（F =130.7, 17.8, 7.18, all P 〈 0.05） in HG group.Compared with HG group, the cell viability of H9c2cells was increased （F =37.3, P 〈0.05） and the apoptosis rate was reduced in HG ＋ BAY group（F =46.5, P 〈 0.05）.At the same time, the protein levels of cleaved-caspase-1, Bax were decreased and Bcl-2 was increased （F =80.5, 7.6, 37.4, all P 〈 0.05）.The mRNA level of caspase-1, Bax were decreased while Bcl-2 mRNA level was decreaed（F=130.7, 17.8, 7.18, all P〈0.05） in HG ＋ BAY group.Conclusion Syk regulates high glucose-induced apoptosis of myocardial cells by re