益心泰对心肌缺血再灌注损伤大鼠JAK2/STAT3信号通路相关蛋白表达的影响

Effects of Yixintai on JAK2/STAT3 Signaling Pathway Protein Expression in Rats with Myocardial Ischemia-Reperfusion Injury

目的观察益心泰对心肌缺血再灌注损伤(MIRI)大鼠JAK2/STAT3信号通路相关蛋白表达的影响,探讨其保护心肌的作用机制。方法采用结扎冠状动脉前降支法建立MIRI大鼠模型。实验大鼠随机分为假手术组、模型组和益心泰低、中、高剂量组。TTC染色检测心肌梗死面积,TUNEL法检测细胞凋亡,ELISA检测白细胞介素(IL)-6、IL-1β和肿瘤坏死因子-α(TNF-α)水平,Western blot检测Bax、Bcl-2、Caspase-3、LC3、Beclin1、p62、JAK2、p-JAK2、STAT3及p-STAT3蛋白表达。结果与假手术组比较,模型组大鼠肌酸激酶同工酶(CK-MB)和心肌肌钙蛋白Ⅰ(c TnⅠ)表达明显升高(P<0.01);心肌梗死面积显著增加(P<0.01);TNF-α、IL-6、IL-1β水平显著升高(P<0.01);LC3Ⅱ/LC3Ⅰ和Beclin 1蛋白表达明显升高(P<0.01),p62蛋白表达明显降低(P<0.01);Bax/Bcl-2和Caspase-3蛋白表达升高,细胞凋亡率明显上升(P<0.01);p-JAK2/JAK2、p-STAT3/STAT显著降低(P<0.01)。与模型组比较,益心泰各剂量组大鼠CK-MB及c TnⅠ表达明显降低(P<0.01);心肌梗死面积显著减少(P<0.01);TNF-α、IL-6、IL-1β水平显著降低(P<0.01);LC3Ⅱ/LC3Ⅰ和Beclin 1蛋白表达明显降低(P<0.01),p62蛋白表达明显升高(P<0.01);Bax/Bcl-2比值和Caspase-3蛋白表达降低,细胞凋亡率明显降低(P<0.01);p-JAK2/JAK2、p-STAT3/STAT显著升高(P<0.01)。JAK2特异性抑制剂AG490可逆转益心泰对MIRI大鼠JAK2/STAT3信号通路相关蛋白表达、心肌损伤标记物、细胞凋亡、自噬及炎症反应的影响。结论益心泰可通过激活JAK2/STAT3信号通路减轻MIRI大鼠炎症反应、抑制细胞凋亡及过度自噬,从而保护心脏。

Objective To observe the effects of Yixintai on JAK2/STAT3 signaling pathway protein expression in rats with myocardial ischemia-reperfusion injury(MIRI);To explore its myocardial protective mechanism. Methods A rat model of MIRI was established by ligating the anterior descending coronary artery. Experimental rats were randomly divided into sham-operation group, model group and Yixintai low-, medium-and high-dosage groups. TTC staining was used to detect the area of myocardial infarction;TUNEL method was used to detect cell apoptosis;ELISA was used to detect the levels of IL-6, IL-1β and TNF-α. Western blot was used to detect Bax, Bcl-2, Caspase-3, LC3, Beclin 1, p62, JAK2, p-JAK2, STAT3 and p-STAT3 protein levels. Results Compared with the sham-operation group, the expressions of CK-MB and c TnⅠ in the model group increased significantly(P<0.01);the area of myocardial infarction increased significantly(P<0.01);the levels of TNF-α, IL-6 and IL-1β increased significantly(P<0.01);expressions of LC3Ⅱ/LC3Ⅰ and Beclin 1 increased significantly(P<0.01), and expression of p62 decreased significantly(P<0.01);expressions of Bax/Bcl-2 and Caspase-3 protein increased, and apoptosis rate increased significantly(P<0.01);p-JAK2/JAK2, p-STAT3/STAT significantly decreased(P<0.01). Compared with the model group, expressions of CK-MB and cTnⅠ in Yixintai groups decreased significantly(P<0.01);myocardial infarction area was significantly reduced(P<0.01);levels of TNF-α, IL-6, IL-1β were significantly reduced(P<0.01);expressionsof LC3Ⅱ/LC3Ⅰ and Beclin 1 protein decreased significantly(P<0.01), and expression of p62 increased significantly(P<0.01);expressions of Bax/Bcl-2 and Caspase-3 decreased, and the apoptosis rate decreased significantly(P<0.01);p-JAK2/JAK2, p-STAT3/STAT increased significantly(P<0.01). The JAK2-specific inhibitor AG490 could reverse the effects of Yixintai on the expressions of JAK2/STAT3 signaling pathway-related proteins, markers of myocardial injury, apoptosis, autophagy, and inflammation in rats with MIRI. Conclusion Yixintai can alleviate MIRI in rats by activating JAK2/STAT3 signaling pathway, inhibit cell apoptosis and excessive autophagy, thereby protecting the heart.