Jiang Shi-Jun
School of Basic Medicine, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China.
World J Diabetes. 2022 Apr 15;13(4):338-357. doi: 10.4239/wjd.v13.i4.338.
Diabetic cardiomyopathy (DCM) is a serious complication of end-stage diabetes that presents symptoms such as cardiac hypertrophy and heart failure. The transient receptor potential channel 6 (TRPC6) protein is a very important selective calcium channel that is closely related to the development of various cardiomyopathies.
To explore whether TRPC6 affects cardiomyocyte apoptosis and proliferation inhibition in DCM.
We compared cardiac function and myocardial pathological changes in wild-type mice and mice injected with streptozotocin (STZ), in addition to comparing the expression of TRPC6 and P-calmodulin-dependent protein kinase II (P-CaMKII) in them. At the same time, we treated H9C2 cardiomyocytes with high glucose and then evaluated the effects of addition of SAR, a TRPC6 inhibitor, and KN-93, a CaMKII inhibitor, to such H9C2 cells in a high-glucose environment.
We found that STZ-treated mice had DCM, decreased cardiac function, necrotic cardiomyocytes, and limited proliferation. Western blot and immunofluorescence were used to detect the expression levels of various appropriate proteins in the myocardial tissue of mice and H9C2 cells. Compared to those in the control group, the expression levels of the apoptosis-related proteins cleaved caspase 3 and Bax were significantly higher in the experimental group, while the expression of the proliferation-related proteins proliferating cell nuclear antigen (PCNA) and CyclinD1 was significantly lower. and , the expression of TRPC6 and P-CaMKII increased in a high-glucose environment. However, addition of inhibitors to H9C2 cells in a high-glucose environment resulted in alleviation of both apoptosis and proliferation inhibition.
The inhibition of apoptosis and proliferation of cardiomyocytes in a high-glucose environment may be closely related to activation of the TRPC6/P-CaMKII pathway.
糖尿病性心肌病(DCM)是终末期糖尿病的一种严重并发症,表现为心脏肥大和心力衰竭等症状。瞬时受体电位通道6(TRPC6)蛋白是一种非常重要的选择性钙通道,与各种心肌病的发展密切相关。
探讨TRPC6是否影响DCM中心肌细胞凋亡和增殖抑制。
我们比较了野生型小鼠和注射链脲佐菌素(STZ)的小鼠的心脏功能和心肌病理变化,此外还比较了它们中TRPC6和钙调蛋白依赖性蛋白激酶II(P-CaMKII)的表达。同时,我们用高糖处理H9C2心肌细胞,然后评估在高糖环境下添加TRPC6抑制剂SAR和CaMKII抑制剂KN-93对这类H9C2细胞的影响。
我们发现STZ处理的小鼠患有DCM,心脏功能下降,心肌细胞坏死,增殖受限。采用蛋白质免疫印迹法和免疫荧光法检测小鼠心肌组织和H9C2细胞中各种相关蛋白的表达水平。与对照组相比,实验组中凋亡相关蛋白裂解的半胱天冬酶3和Bax的表达水平显著升高,而增殖相关蛋白增殖细胞核抗原(PCNA)和细胞周期蛋白D1的表达显著降低。并且,在高糖环境下TRPC6和P-CaMKII的表达增加。然而,在高糖环境下向H9C2细胞中添加抑制剂可减轻凋亡和增殖抑制。
高糖环境下心肌细胞凋亡和增殖的抑制可能与TRPC6/P-CaMKII途径的激活密切相关。