Objective To investigate the roles of glucose-regulated protein 75(GRP75)and voltage-dependent anion channel 1(VDAC1)in heroin-induced arrhythmia.Methods Based on transcriptomic data from primary myocardial cells treated with heroin and the GSE31821 dataset from the Gene Expression Omnibus(GEO),differentially expressed genes(DEGs)were identified using R software.Enrichment analysis of DEGs was performed.The protein-protein interaction(PPI)network was constructed using STRING database,and key genes were selected using Cytoscape.Molecular docking of key genes was performed using HDOCK,followed by in vivo valida-tion.A total of 60 SD rats were randomly divided into control,model,model+7 d,model+14 d,and model+21 d groups.A rat model of heroin addiction was established,and the expression levels of DEGs in myocardial tissue were assessed using immunohistochemical staining and quantitative real-time PCR.Results A total of 51 DEGs primarily enriched in muscle cell development,myofibrils,actin binding,arrhythmic right ventricular cardiomyopathy,calcium signaling,and apoptosis pathways were identified.Based on the PPI and Cytoscape analyses,GRP75 and VDAC1 were identified as key genes.Molecular docking indicated a strong interaction between GRP75 and VDAC1,which form a stable complex.The results of immunohistochemical staining and qRT-PCR showed that the expression levels of GRP75 and VDAC1 were significantly increased in the model group compared to those in the control group(P＜0.05),and their expres-sion increased(P＜0.05)with the intervention period of heroin in a time-dependent manner.Conclusion GRP75 and VDAC1 may con-tribute to heroin-induced arrhythmogenesis.

Objective To investigate the roles of glucose-regulated protein 75(GRP75)and voltage-dependent anion channel 1(VDAC1)in heroin-induced arrhythmia.Methods Based on transcriptomic data from primary myocardial cells treated with heroin and the GSE31821 dataset from the Gene Expression Omnibus(GEO),differentially expressed genes(DEGs)were identified using R software.Enrichment analysis of DEGs was performed.The protein-protein interaction(PPI)network was constructed using STRING database,and key genes were selected using Cytoscape.Molecular docking of key genes was performed using HDOCK,followed by in vivo valida-tion.A total of 60 SD rats were randomly divided into control,model,model+7 d,model+14 d,and model+21 d groups.A rat model of heroin addiction was established,and the expression levels of DEGs in myocardial tissue were assessed using immunohistochemical staining and quantitative real-time PCR.Results A total of 51 DEGs primarily enriched in muscle cell development,myofibrils,actin binding,arrhythmic right ventricular cardiomyopathy,calcium signaling,and apoptosis pathways were identified.Based on the PPI and Cytoscape analyses,GRP75 and VDAC1 were identified as key genes.Molecular docking indicated a strong interaction between GRP75 and VDAC1,which form a stable complex.The results of immunohistochemical staining and qRT-PCR showed that the expression levels of GRP75 and VDAC1 were significantly increased in the model group compared to those in the control group(P＜0.05),and their expres-sion increased(P＜0.05)with the intervention period of heroin in a time-dependent manner.Conclusion GRP75 and VDAC1 may con-tribute to heroin-induced arrhythmogenesis.

Objective To investigate the role of HK2 and VDAC1 in diacetylmorphine-induced cardiomyocyte apoptosis.Methods A dose-escalation method was used to establish a rat model of diacetylmorphine addiction.Forty SD rats were randomly divided into three groups,the normal group(n=10)was injected with an equal amount of saline subcutaneously,the model group(n=15)was injected with 5 mg/kg of diacetylmorphine for the first time,and then the dose was increased by 2.5 mg/(kg·d)day by day for 20 days,and the group of model +10 D(n=15)continued to increase the dose based on the model group up to the 10th day.Lactate dehydrogenase(LDH)and glutamic oxaloacetic transaminase(GOT)were detected by ELISA;HE staining was used to observe the pathological changes of myocardial tissues in each group;TUNEL staining was used to detect apoptosis in myocardial tissues in each group;and immunohistochemistry,RT-q-analysis,and immunochemistry were used to detect apoptosis in myocardial tissues in each group.Immunohistochemistry,RT-qPCR and Western bl-ot were used to detect the mRNA and protein expression of HK2,VDAC1 and apoptosis-related factors.Results HE staining revealed that myocardial tissues exhibited different degrees of damage with the prolongation of diacetylmorphine intervention.Compared with the normal group,serum LDH,GOT content and myocardial apoptosis rate increased in the model group,mRNA and protein levels of HK2 and anti-apoptotic factor Bcl-2 decreased,mRNA and protein levels of VDAC1 and pro-apoptotic factors Bax and Caspase-3 increased,and the protein level of Clevead Caspase-3 increased;in the model +10 D group the above indexes,there was a statistically significant difference(P<0.05).Conclusion Diacetylmorphine can cause cardiomyocyte apoptosis,and VDAC1 may be involved in the process of cardiomyocyte apoptosis caused by diacetylmorphine.