转录因子FLI-1通过上调Klotho基因改善心肌细胞肥大

FLI-1 ameliorates cardiac hypertrophy by inhibiting IGF-1R/Gi/PLC pathway via up-regulation of Klotho

目的探讨转录因子FLI-1通过Klotho介导的IGF-1R/Gi/PLC途径对心肌细胞肥大的影响。方法将大鼠心肌细胞(H9c2)分为对照组、模型组、模型+NC Vector组、模型+pcDNA-FLI-1组、模型+NC Vector+NC siRNA组、模型+NC Vector+Klotho siRNA组、模型+pcDNA-FLI-1+NC siRNA组和模型+pcDNA-FLI-1+Klotho siRNA组等共8组。通过用异丙肾上腺素(isoproterenol,ISO)处理细胞,建立心肌细胞肥大模型,细胞分别转染pcDNA-FLI-1和Klotho siRNA。采用流式细胞术观测细胞凋亡,鬼笔环肽染色观测细胞肥大面积;采用Western blot检测细胞凋亡、肥大及IGF-1R/Gi/PLC途径相关蛋白的表达。结果与对照组比较,模型组细胞凋亡率、心肌细胞表面积及IGF-1R、GNAI1和PLCG1表达显著增加(P<0.05),表明建模成功;与模型+NC Vector组比较,模型+pcDNA-FLI-1组细胞凋亡、心肌细胞表面积及IGF-1R、GNAI1和PLCG1表达显著降低(P<0.05)。与模型+NC Vector+NC siRNA组相比,模型+NC Vector+Klotho siRNA组细胞凋亡、心肌细胞表面积及IGF-1R、GNAI1和PLCG1表达显著增加(P<0.05);与模型+pcDNA-FLI-1+NC siRNA组相比,模型+pcDNA-FLI-1+Klotho siRNA组细胞凋亡、心肌细胞表面积及IGF-1R、GNAI1和PLCG1表达显著降低(P<0.05)。结论FLI-1能够通过上调Klotho抑制IGF-1R/Gi/PLC途径,减轻心肌细胞凋亡及心肌细胞肥大面积。

Objective To investigate the effect of FLI-1 on Klotho-mediated IGF-1R/Gi/PLC pathway on cardiomyocyte hypertrophy.Methods The cells were divided into 8 groups:control group,model group,model+NC Vector group,model+pcDNA-FLI-1 group,model+NC Vector+NC siRNA group,model+NC Vector+Klotho siRNA group,model+pcDNA-FLI-1+NC siRNA group and model+pcDNA-FLI-1+Klotho siRNA group.Cardiomyocyte hypertrophy models were established by treating cells with isoproterenol(ISO),and the latter cells were transfected with pcDNA-FLI-1 and Klotho siRNA,respectively.Apoptosis was detected by flow cytometry;hypertrophic area was detected by phalloidin staining;apoptosis,hypertrophy and expression of IGF-1R/Gi/PLC pathway-related proteins were detected by Western blotting.Results Compared with the control group,the ISO group had increased apoptotic rate,cardiomyocyte surface area and IGF-1R,GNAI1 and PLCG1 expression,indicating successful modeling;compared with the model+NC Vector group,the model+pcDNA-FLI-1 group had decreased apoptosis,cardiomyocyte surface area and IGF-1R,GNAI1 and PLCG1 expression.Apoptosis,cardiomyocyte surface area,and IGF-1R,GNAI1 and PLCG1 expression were increased in the model+NC Vector+Klotho siRNA group compared with the model+NC Vector+NC siRNA group;apoptosis,cardiomyocyte surface area,and IGF-1R,GNAI1 and PLCG1 expression were decreased in the model+pcDNA-FLI-1+Klotho siRNA group compared with the model+pcDNA-FLI-1+NC siRNA group.Conclusion FLI-1 can inhibit IGF-1R/Gi/PLC pathway and reduce myocardial apoptosis and myocardial hypertrophy by up-regulating Klotho.