Experimental Studies Of Transient Receptor Potential Vanilloid-3 In Pressure Overload-Induced Cardiac Hypertrophy

Background Cardiac hypertrophy is a compensatory response when the body is underlying harmful stimuli(such as pressure overload,etc.).Continuous cardiac hypertrophy can cause a series of cardiovascular diseases,eventually develop into heart failure and endanger the life of patients.At present,the clinical intervention measures for cardiac hypertrophy are relatively limited.The research and clarification of the mechanism of cardiac hypertrophy can provide new ways and ideas for clinical treatment of patients with cardiac hypertrophy.Objective To explore whether transient receptor potential vanillin-3(TRPV3)participate in the occurrence and development of cardiac hypertrophy by regulating mitochondrial function during pressure overload.Methods(1)Healthy male SD rats(160 ± 10)g were randomly divided into sham operation group(Sham),abdominal aorta constriction group(AAC),and cromolyn sodium treatment group(CS),with 12 rats in each group.After 4 and 8 weeks of normal feeding,calculating the HW/BW,LW/BW,HW/TL and LW/TL of rats in each group;The cross sectional area of myocardial cells in each group was observed by HE staining;Expression of myosin heavy chain β(β-MHC),total cardiac protein TRPV3,NOX4 and mitochondrial protein TRPV3,NOX4 were detected by western blotting;The activities of mitochondrial complex I,complex III and ATP were measured spectrophotometrically;The generation of reactive oxygen species and mitochondrial membrane potential were detected by immunofluorescence.(2)H9C2 cardiomyocytes in exponential growth phase were divided into blank control group,negative control group,AngⅡ treatment group and TRPV3 silenced group.The protein expression of β-MHC,TRPV3 and NOX4 were detected by western blotting;The activities of mitochondrial complex I,complex III and ATP were measured by spectrophotometer;The generation of reactive oxygen species and membrane potential was detected by immunofluorescence.(3)To study the effect of mast cell mediator on TRPV3 expression,H9C2 myocardial cells were divided into blank control group,heparin treatment group,histamine treatment group and serotonin treatment group.Results(1)With the pressure load increases,HW/BW,LW/BW,HW/TL and LW/TL were increased,the cross-sectional area of myocardial cells were increased,and the marker protein of cardiac hypertrophy β-MHC expression were increased,and the above phenomenon was decreased after treatment with sodium cromoglycate.(2)With the pressure load increase,the total cardiac protein TRPV3 and mitochondrial TRPV3 were increased;Compared with the AAC group,the total cardiac protein TRPV3 were decreased by treatment with sodium cromoglycate at 4 and 8 weeks.At 4 weeks,the expression of mitochondrial protein TRPV3 did not change significantly in sodium cromoglycate treatment group,while the expression of mitochondrial protein TRPV3 was decreased after 8 weeks of sodium cromoglycate treatment.(3)With the pressure load increase,cardiac ROS production,ATP production and mitochondrial membrane potential were decreased,and activities of mitochondrial complex I and complex III were decreased;The above phenomenon was decreased by treatment with sodium cromoglycate treatment.(4)Compared with the control group,the protein expression of TRPV3,NOX4,and ROS production were increased,ATP production and mitochondrial membrane potential were decreased,enzyme activities of mitochondrial complex I and complex III were decreased,the protein expression of β-MHC was increased in H9C2 cardiomyocytes treated with AngⅡ;Compared with the model group,after TRPV3 scilence,the protein expression of NOX4 and ROS production were decreased,ATP production was increased,mitochondrial membrane potential was increased,and the enzyme activities of mitochondrial complex I and complex III were increased,the protein expression of β-MHC was decreased.(5)Compared with the control group,the expression of TRPV3 protein were increased in H9C2 cardiomyocytes treated with heparin,histamine and serotonin.Conclusion When the pressure load increases,the myocardial TRPV3 expression can be upregulated by heparin,histamine and serotonin released by mast cells,and then further increases the mitochondrial dysfunction by up-regulating NOX4 to participate in the process of cardiac hypertrophy induced by pressure overload.