SOCS2调节PI3K/AKT轴对阿霉素诱导的大鼠心力衰竭和心肌细胞凋亡的影响研究

The effect of SOCS2 on the PI3K/AKT axis in doxorubicin-induced heart failure and cardiomyocyte apoptosis in rats

关键词:  细胞因子信号抑制因子2  PI3K/AKT信号轴  阿霉素  心力衰竭  心肌细胞凋亡

Key words:  Suppressor of cytokine signaling 2  PI3K/AKT signaling axis  Doxorubicin  Heart failure  Cardiomyocyte apoptosis

摘要:

目的 探讨细胞因子信号抑制因子2（SOCS2）调节PI3K/AKT信号通路对阿霉素（DOX）诱导大鼠心力衰竭及心肌细胞凋亡的影响。方法 50只雄性Sprague-Dawley大鼠随机分为5组（n=10）：正常对照组（NC）、DOX模型组（DOX）、SOCS2低剂量组（SOCS2-L，0.5 mg/kg）、中剂量组（SOCS2-M，1.0 mg/kg）及高剂量组（SOCS2-H，2.0 mg/kg）。DOX组及SOCS2干预组通过尾静脉注射DOX（2.5 mg/kg，每周1次，6周，总剂量15 mg/kg）建立心力衰竭模型，NC组注射等体积生理盐水。SOCS2组同期每周注射相应剂量SOCS2重组蛋白。实验第8周末，采用超声心动图测定左心室内径舒张末期（LVIDd）、收缩末期（LVIDs）、短轴缩短率（FS）及射血分数（EF）；Masson染色评估胶原容积分数（CVF）及心肌周围血管胶原面积（PVCA）；TUNEL染色检测心肌细胞凋亡率；RT-qPCR及Western blot检测PI3K、AKT mRNA及蛋白表达水平。结果 与NC组比较，DOX组LVIDd、LVIDs、CVF、PVCA、心肌细胞凋亡率升高，FS、EF水平降低（P<0.05）；与DOX组比较，SOCS2低中高剂量组LVIDd、LVIDs、CVF、PVCA、心肌细胞凋亡率降低，FS、EF水平升高（P<0.05），且随着SOCS2重组蛋白剂量逐渐升高，LVIDd、LVIDs、CVF、PVCA、心肌细胞凋亡率逐渐降低，FS、EF水平逐渐升高，各指标呈剂量-效应关系（P<0.05）。与NC组比较，DOX组PI3K、AKT mRNA及蛋白表达降低（P<0.05）；与DOX组比较，SOCS2低中高剂量组PI3K、AKT mRNA及蛋白表达升高（P<0.05），且随着SOCS2剂量升高，PI3K、AKT mRNA及蛋白表达逐渐升高，呈明显剂量-效应关系（P<0.05）。结论 SOCS2重组蛋白通过上调PI3K/AKT通路活性，剂量依赖性改善DOX诱导的大鼠心力衰竭，减轻心肌纤维化及细胞凋亡，提示SOCS2为潜在的药物性心肌病治疗靶点，其临床转化价值值得进一步探索。

Abstract:

Objective: To investigate the effect of suppressor of cytokine signaling 2 (SOCS2) on the PI3K/AKT signaling pathway in doxorubicin (DOX)-induced heart failure and cardiomyocyte apoptosis in rats. Methods: Fifty male Sprague-Dawley rats were randomly divided into five groups (n = 10): normal control group (NC), DOX model group (DOX), SOCS2 low-dose group (SOCS2-L, 0.5 mg/kg), medium-dose group (SOCS2-M, 1.0 mg/kg), and high-dose group (SOCS2-H, 2.0 mg/kg). The DOX group and SOCS2 intervention groups were injected with DOX (2.5 mg/kg, once a week for 6 weeks, total dose 15 mg/kg) via the tail vein to establish heart failure models, while the NC group was injected with an equal volume of normal saline. The SOCS2 groups were injected with the corresponding dose of SOCS2 recombinant protein weekly. At the end of the 8th week of the experiment, left ventricular end-diastolic diameter (LVIDd), left ventricular end-systolic diameter (LVIDs), collagen volume fraction (CVF), perivascular collagen area (PVCA), and cardiomyocyte apoptosis rate were measured by echocardiography and Masson staining, respectively. Cardiomyocyte apoptosis was detected by TUNEL staining. The expression levels of PI3K and AKT mRNA and protein were detected by RT-qPCR and Western blot, respectively. Results: Compared with the NC group, the DOX group had increased LVIDd, LVIDs, CVF, PVCA, and cardiomyocyte apoptosis rate, and decreased fractional shortening (FS) and ejection fraction (EF) (P<0.05). Compared with the DOX group, the SOCS2 low-, medium-, and high-dose groups had decreased LVIDd, LVIDs, CVF, PVCA, and cardiomyocyte apoptosis rate, and increased FS and EF (P<0.05). Moreover, as the dose of SOCS2 recombinant protein increased, LVIDd, LVIDs, CVF, PVCA, and cardiomyocyte apoptosis rate decreased, and FS and EF increased, showing a dose-effect relationship (P<0.05). Compared with the NC group, the DOX group had decreased expression of PI3K and AKT mRNA and protein (P<0.05). Compared with the DOX group, the SOCS2 low-, medium-, and high-dose groups had increased expression of PI3K and AKT mRNA and protein (P<0.05). Moreover, as the dose of SOCS2 increased, the expression of PI3K and AKT mRNA and protein gradually increased, showing a significant dose-effect relationship (P<0.05). Conclusion: SOCS2 recombinant protein improves doxorubicin-induced heart failure in rats in a dose-dependent manner by up-regulating the activity of the PI3K/AKT pathway, reduces myocardial fibrosis and cardiomyocyte apoptosis, and suggests that SOCS2 is a potential therapeutic target for drug-induced cardiomyopathy, and its clinical application value is worthy of further exploration.