Study On The Protective Effect And Mechanism Of Curcumin Nanoparticles On Myocardial Cell Injury Induced By High Fat

Objectives: H9c2 cells were stimulated with high-fat to simulate hyperlipidemia-induced damage to cardiomyocytes.Preconditioning curcumin nanoparticles were used to observe cell proliferation,oxidative stress,apoptosis and morphological changes associated with cell injury,and endoplasmic reticulum stress and related protein expression in the apoptotic pathway.To investigate the protective effect of curcumin nanoparticles on lipotoxicity of myocardial cells and its mechanism.Methods:(1)Establish a high-fat-induced H9c2 cardiomyocyte injury model: select concentrations of 0.1,0.2,0.4,and 0.8 mmol/L palmitic acid(PA)solution to stimulate H9c2 cardiomyocytes,0.4 mmol/L PA the cells were stimulated for 12 h,24 h and 48 h respectively.The suitable concentration of PA and the stimulation time were selected to establish a high-fat-induced H9c2 cardiomyocyte injury model.(2)Protective effect of curcumin nanoparticles(Cur-NPs)on hyperlipid-induced H9c2 cardiomyocyte injury:when H9c2 cells were grown to 80%-90% in culture dishes,PA 0.4 mmol/L was used for 24 h after pretreatment with different concentrations of Cur-NPs for 2 h,using MTT assay to detect cell proliferation in each group.The cells were subcultured into 5 groups: normal control group;PA 0.2 mmol/L group,PA 0.2 mmol/L+Cur-NPs 200 ?mol/L group;PA 0.4 mmol/L group,PA 0.4 mmol/L+ Cur-NPs 200 ?mol/L group.Pretreatment with Cur-NPs(200 ?mol/L)for 2 h followed by stimulation with PA 0.4 mmol/L for 24 h.The prolifer-ation of cells in each group was detected by MTT assay;reactive oxygen species(ROS)were used for each group of cells;using Annexin V-FITC/PI and Tunel kits to detect apopto-sis in each group;ER stress-related proteins(GRP78,CHOP,ATF-4,P-IRE1)were detected by western blotting.The expression level of apoptosis-related proteins(Bcl-2,BAX,caspase-3).Results:(1)When the concentration of 0.4 mmol/L PA stimulated H9c2 cardiomy-ocytes for 24 h,the cell proliferation rate was significantly decreased.After pretreatment with Cur-NPs(200 ?mol/L),the proliferation rate of PA+Cur-NPs group compared with PA model group was significantly increased.It has picked up.(2)When PA stimulated H9c2 cardiomyocytes for 24 h,the level of ROS increased significantly.Significant pathological changes in cell morphology,for example,the cell volume decreased,the connections decreased,the number decreased,the nucleoplasm condensed,and the nuclear membrane nucleolus broken.After pretreatment with Cur-NPs(200 ?mol/L),the cells in the PA+Cur-NPs group returned to normal morphology compared with the PA model group,and the number was similar to that of the normal control group.(3)When PA stimulated H9c2 cardiomyocytes for 24 h,the apoptosis increased significantly.For example,the number of cells decreased,and both the cytoplasm and the nucleus showed significant apoptosis-related morphological changes(nuclear pyknosis,nuclear fragmentation,capsule rupture,and cell content spillover).After pretreatment with Cur-NPs(200 ?mol/L),the apoptosis of PA+Cur-NPs group was significantly reduced compared with PA model group,and the number of cells and cell morphology returned to normal,which was close to the normal control group.(4)When PA stimulated H9c2 cardiomyocytes for 24 h,the expression of ERS signaling pathway related proteins(GRP78,CHOP,ATF-4,P-IRE1)and caspase-3 increased,and the ratio of BAX/Bcl-2 increased;After pretreatment with Cur-NPs(200 ?mol/L),the expression of ERS signaling pathway related proteins(GRP78,CHOP,ATF-4,P-IRE1)and caspase-3 decreased,and the ratio of BAX/Bcl-2 decreased.Conclusions:(1)When H9c2 was administered with 0.4 mmol/L PA and the stimula-tion time was 24 h,it could significantly inhibit cell proliferation,indicating that the lipotoxic cardiomyocyte injury model was successfully established.(2)When the concentra-tion of pretreated Cur-NPs was 200 ?mol/L,the damage induced by high-fat-induced cell proliferation could be restored,the generation of ROS in cells under high-fat conditions was reduced,the apoptosis of cells was reduced,and the normal morphology of cells was restored.(3)When the concentration of pretreated Cur-NPs was 200 ?mol/L,high lipidinduced activation of the ERS signaling pathway and apoptotic signaling pathway could be inhibited.