OBJECTIVE: To observe the effect of electroacupuncture (EA) pretreatment of "biaoben acupoint combination" on cardiomyocyte mitochondrial fission in the rats with myocardial ischemia-reperfusion injury (MIRI) and explore its mechanism. METHODS: Fifty male SD rats were randomly divided into a sham-operation group, a model group, an EA pretreatment group, an EA pretreatment + Compound C group and an EA pretreatment+ML385 group, 10 rats in each group. In the EA pretreatment, the EA pretreatment + Compound C group and the EA pretreatment+ML385 group, EA was delivered at bilateral "Neiguan" (PC6), "Zusanli" (ST36) and "Guanyuan" (CV4) for 20 min, with continuous wave and 2 Hz of frequency, 1 mA of current, once daily for consecutive 7 days. On day 8, in the EA pretreatment + Compound C group and the EA pretreatment+ML385 group, 30 min before model preparation, the intraperitoneal injection with Compound C (0.3 mg/kg) and ML385 (30 mg/kg) was administered respectively. Except in the sham-operation group, the ligation of the left anterior descending coronary artery was performed to prepare MIRI rat model in the rest groups. In the sham-operation group, the thread was not ligated. After modeling, the content of reactive oxygen species (ROS) in the ischemic area was measured by flow cytometry, superoxide dismutase (SOD) was detected using xanthine oxidase method, and malondialdelyde (MDA) was detected using thiobarbituric acid (TBA) chromatometry. The morphology of myocardial tissue in the ischemic area was observed with HE staining, and the mitochondria ultrastructure of cardiomyocytes observed under transmission electron microscopy. Using immunofluorescence analysis, the positive expression of mitochondrial fission factor (MFF), mitochondrial fission 1 protein antibody (Fis1) and dynamin-related protein 1 (Drp1) was detected; and with immunohistochemical method used, the protein expression of adenosine monophosphate-activated protein kinase (AMPK), nuclear factor E2-associated factor2 (Nrf2) and Drp1 in the ischemic area was detected. RESULTS: Compared with the sham-operation group, the content of ROS and MDA in the myocardial tissue of the ischemic area, and the positive expression of MFF, Fis1 and Drp1 increased in the model group (P<0.01); the content of SOD and the protein expression of AMRK and Nrf2 decreased (P<0.01), and the protein expression of Drp1 elevated (P<0.01). Compared with the model group, the content of ROS and MDA in the myocardial tissue of the ischemic area, and the positive expression of MFF, Fis1 and Drp1 were dropped in the EA pretreatment group (P<0.01); the content of SOD and the protein expression of AMRK and Nrf2 rose (P<0.01), and the protein expression of Drp1 declined (P<0.01); and in the EA pretreatment+Compound C group and the EA pretreatment+ML385 group, the positive expression of MFF, Fis1 and Drp1, and the protein expression of Drp1 were all reduced (P<0.01). When compared with the EA pretreatment + Compound C group and the EA pretreatment+ML385 group, the content of ROS and MDA in the myocardial tissue of the ischemic area, and the positive expression of MFF, Fis1 and Drp1 were dropped in the EA pretreatment group (P<0.01); the content of SOD and the protein expression of AMRK and Nrf2 rose (P<0.01, P<0.05), and the protein expression of Drp1 decreased (P<0.05). In comparison with the model group, the EA pretreatment+Compound C group and the EA pretreatment+ML385 group, the cardiac muscle fiber rupture, cell swelling and mitochondrial disorders were obviously alleviated in the EA pretreatment group. The morphological changes were similar among the model group, the EA pretreatment+Compound C group and the EA pretreatment+ML385 group. CONCLUSION Electroacupuncture pretreatment of "biaoben acupoint combination" attenuates myocardial injury in MIRI rats, probably through promoting the phosphorylation of AMPK and Nrf2, inhibiting the excessive mitochondrial fission induced by Drp1, and reducing mitochondrial dysfunction caused by mitochondrial fragmentation and vacuolation.
Animals ; Electroacupuncture ; Male ; Rats, Sprague-Dawley ; Myocardial Reperfusion Injury/physiopathology* ; Myocytes, Cardiac/cytology* ; Rats ; Acupuncture Points ; Mitochondrial Dynamics ; Humans ; Reactive Oxygen Species/metabolism* ; NF-E2-Related Factor 2/genetics* ; Superoxide Dismutase/metabolism*

BACKGROUND: Salvianolate is a compound mainly composed of salvia magnesium acetate, which is extracted from the Chinese herb Salvia miltiorrhiza . In recent years, salvianolate injection has been widely used in the treatment of cardiovascular diseases, but the mechanism of how it can alleviate cardiotoxicity remains unclear. METHODS: The cardiac injury model was constructed by treatment with doxorubicin (Dox) or azithromycin (Azi) in zebrafish larvae. Heart phenotype, heart rate, and cardiomyocyte apoptosis were observed in the study. RNA-sequencing (RNA-seq) analysis was used to explore the underlying mechanism of salvianolate treatment. Moreover, cardiomyocyte autophagy was assessed by in situ imaging. In addition, the miR-30a/becn1 axis regulation by salvianolate was further investigated. RESULTS: Salvianolate treatment reduced the proportion of pericardial edema, recovered heart rate, and inhibited cardiomyocyte apoptosis in Dox/Azi-administered zebrafish larvae. Mechanistically, salvianolate regulated the lysosomal pathway and promoted autophagic flux in zebrafish cardiomyocytes. The expression level of becn1 was increased in Dox-induced myocardial tissue injury after salvianolate administration; overexpression of becn1 in cardiomyocytes alleviated the Dox/Azi-induced cardiac injury and promoted autophagic flux in cardiomyocytes, while becn1 knockdown blocked the effects of salvianolate. In addition, miR-30a, negatively regulated by salvianolate, partially inhibited the cardiac amelioration of salvianolate by targeting becn1  directly. CONCLUSION This study has proved that salvianolate reduces cardiomyopathy by regulating autophagic flux through the miR-30a/becn1 axis in zebrafish and is a potential drug for adjunctive Dox/Azi therapy.
Animals ; Zebrafish ; MicroRNAs/genetics* ; Autophagy/drug effects* ; Myocytes, Cardiac/metabolism* ; Cardiomyopathies/metabolism* ; Beclin-1/genetics* ; Apoptosis/drug effects* ; Plant Extracts/therapeutic use* ; Doxorubicin

BACKGROUND: The protective effect of mesenchymal stem cells (MSCs) on cardiac ischemia-reperfusion (I/R) injury has been widely reported. Dental pulp-derived mesenchymal stem cells (DP-MSCs) have therapeutic effects on various diseases, including diabetes and cirrhosis. This study aimed to determine the therapeutic effects of DP-MSCs on I/R injury and elucidate the underlying mechanism. METHODS: Myocardial I/R injury model mice were treated with DP-MSCs or a miR-19a-3p mimic. The infarct volume, fibrotic area, pyroptosis, inflammation level, and cardiac function were measured. Cardiomyocytes exposed to hypoxia-reoxygenation were transfected with the miR-19a-3p mimic, miR-19a-3p inhibitor, or negative control. Pyroptosis and protein expression in the interferon regulatory factor 8/mitogen-activated protein kinase (IRF-8/MAPK) pathway were measured. RESULTS: DP-MSCs protected cardiac function in cardiac I/R-injured mice and inhibited cardiomyocyte pyroptosis. The upregulation of miR-19a-3p protected cardiac function, inhibited cardiomyocyte pyroptosis, and inhibited IRF-8/MAPK signaling in cardiac I/R-injured mice. DP-MSCs inhibited cardiomyocyte pyroptosis and the IRF-8/MAPK signaling by upregulating the miR-19a-3p levels in cardiomyocytes injured by I/R. CONCLUSION DP-MSCs protected cardiac function by inhibiting cardiomyocyte pyroptosis through miR-19a-3p under I/R conditions.
Animals ; MicroRNAs/metabolism* ; Pyroptosis/genetics* ; Mesenchymal Stem Cells/metabolism* ; Myocytes, Cardiac/cytology* ; Mice ; Male ; Mice, Inbred C57BL ; Dental Pulp/cytology* ; Myocardial Reperfusion Injury/therapy* ; MAP Kinase Signaling System/physiology*

The current study aimed to clarify the roles of apolipoprotein A5 (ApoA5) and milk fat globule-epidermal growth factor 8 (Mfge8) in regulating myocardial lipid deposition and the regulatory relationship between them. The serum levels of ApoA5 and Mfge8 in obese and healthy people were compared, and the obesity mouse model induced by the high-fat diet (HFD) was established. In addition, primary cardiomyocytes were purified and identified from the hearts of suckling mice. The 0.8 mmol/L sodium palmitate treatment was used to establish the lipid deposition cardiomyocyte model in vitro. ApoA5-overexpressing adenovirus was used to observe its effects on cardiac function and lipids. The expressions of the fatty acid uptake-related molecules and Mfge8 on transcription or translation levels were detected. Co-immunoprecipitation was used to verify the interaction between ApoA5 and Mfge8 proteins. Immunofluorescence was used to observe the co-localization of Mfge8 protein with ApoA5 or lysosome-associated membrane protein 2 (LAMP2). Recombinant rMfge8 was added to cardiomyocytes to investigate the regulatory mechanism of ApoA5 on Mfge8. The results showed that participants in the simple obesity group had a significant decrease in serum ApoA5 levels (P < 0.05) and a significant increase in Mfge8 levels (P < 0.05) in comparison with the healthy control group. The adenovirus treatment successfully overexpressed ApoA5 in HFD-fed obese mice and palmitic acid-induced lipid deposition cardiomyocytes, respectively. ApoA5 reduced the weight of HFD-fed obese mice (P < 0.05), shortened left ventricular isovolumic relaxation time (IVRT), increased left ventricular ejection fraction (LVEF), and significantly reduced plasma levels of triglycerides (TG) and cholesterol (CHOL) (P < 0.05). In myocardial tissue and cardiomyocytes, the overexpression of ApoA5 significantly reduced the deposition of TG (P < 0.05), transcription of fatty acid translocase (FAT/CD36) (P < 0.05), fatty acid-binding protein (FABP) (P < 0.05), and fatty acid transport protein (FATP) (P < 0.05), and protein expression of Mfge8 (P < 0.05), while the transcription levels of Mfge8 were not significantly altered (P > 0.05). In vitro, the Mfge8 protein was captured using ApoA5 as bait protein, indicating a direct interaction between them. Overexpression of ApoA5 led to an increase in co-localization of Mfge8 with ApoA5 or LAMP2 in cardiomyocytes under lipid deposition status. On this basis, exogenous added recombinant rMfge8 counteracted the improvement of lipid deposition in cardiomyocytes by ApoA5. The above results indicate that the overexpression of ApoA5 can reduce fatty acid uptake in myocardial cells under lipid deposition status by regulating the content and cellular localization of Mfge8 protein, thereby significantly reducing myocardial lipid deposition and improving cardiac diastolic and systolic function.
Animals ; Humans ; Mice ; Myocytes, Cardiac/metabolism* ; Obesity/physiopathology* ; Male ; Apolipoprotein A-V/blood* ; Lipid Metabolism/physiology* ; Milk Proteins/blood* ; Myocardium/metabolism* ; Diet, High-Fat ; Antigens, Surface/physiology* ; Mice, Inbred C57BL ; Cells, Cultured ; Female

The study aims to examine the effects and potential mechanisms of disulfiram (DSF) on cardiac hypertrophic injury, focusing on the role of transforming growth factor-β-activated kinase 1 (TAK1)-mediated pan-apoptosis (PANoptosis). H9C2 cardiomyocytes were treated with angiotensin II (Ang II, 1 µmol/L) to establish an in vitro model of myocardial hypertrophy. DSF (40 µmol/L) was used to treat cardiomyocyte hypertrophic injury models, either along or in combination with the TAK1 inhibitor, 5z-7-oxozeaenol (5z-7, 0.1 µmol/L). We assessed cell damage using propidium iodide (PI) staining, measured cell viability with CCK8 assay, quantified inflammatory factor levels in cell culture media via ELISA, detected TAK1 and RIPK1 binding rates using immunoprecipitation, and analyzed the protein expression levels of key proteins in the TAK1-mediated PANoptosis pathway using Western blot. In addition, the surface area of cardiomyocytes was measured with Phalloidin staining. The results showed that Ang II significantly reduced the cellular viability of H9C2 cardiomyocytes and the binding rate of TAK1 and RIPK1, significantly increased the surface area of H9C2 cardiomyocytes, PI staining positive rate, levels of inflammatory factors [interleukin-1β (IL-1β), IL-18, and tumor necrosis factor α (TNF-α)] in cell culture media and p-TAK1/TAK1 ratio, and significantly up-regulated key proteins in the PANoptosis pathway [pyroptosis-related proteins NLRP3, Caspase-1 (p20), and GSDMD-N (p30), apoptosis-related proteins Caspase-3 (p17), Caspase-7 (p20), and Caspase-8 (p18), as well as necroptosis-related proteins p-MLKL, RIPK1, and RIPK3]. DSF significantly reversed the above changes induced by Ang II. Both 5z-7 and exogenous IL-1β weakened these cardioprotective effects of DSF. These results suggest that DSF may alleviate cardiac hypertrophic injury by inhibiting TAK1-mediated PANoptosis.
Animals ; MAP Kinase Kinase Kinases/physiology* ; Rats ; Myocytes, Cardiac/pathology* ; Disulfiram/pharmacology* ; Cardiomegaly ; Apoptosis/drug effects* ; Cell Line ; Angiotensin II ; Necroptosis/drug effects* ; Interleukin-1beta/metabolism* ; Receptor-Interacting Protein Serine-Threonine Kinases/metabolism* ; Lactones ; Resorcinols ; Zearalenone/administration & dosage*

OBJECTIVES: To investigate the mechanism through which N-acetylneuraminic acid (Neu5Ac) exacerbates hypoxia/reoxygenation (H/R) injury in rat cardiomyocytes (H9C2 cells). METHODS: H9C2 cells were cultured in hypoxia and glucose deprivation for 8 h followed by reoxygenation for different durations to determine the optimal reoxygenation time. Under the optimal H/R protocol, the cells were treated with 0, 5, 10, 20, 30, 40, 50, and 60 mmol/L Neu5Ac during reoxygenation to explore the optimal drug concentration. The cells were then subjected to H/R injury followed by treatment with Neu5Ac, Fer-1 (a ferroptosis inhibitor), or both. The changes in SOD activity, intracellular Fe²⁺ and lipid ROS levels in the cells were evaluated, and the cellular expressions of Nrf2, GPX4, HO-1, FSP1, and xCT proteins were detected using Western blotting. RESULTS: Following hypoxia and glucose deprivation for 8 h, the cells with reoxygenation for 6 h, as compared with other time lengths of reoxygenation except for 9 h, showed the lowest expression levels of Nrf2, GPX4, HO-1, and FSP1 proteins (P<0.001). Neu5Ac treatment of dose-dependently decreased the viability of the cells with H/R injury with an IC₅₀ of 30.07 mmol/L. Reoxygenation for 3 h with normal glucose supplementation and a Neu5Ac concentration of 30 mmol/L were selected as the optimal conditions in the subsequent experiments. The results showed that Neu5Ac could significantly increase SOD activity, Fe²⁺ and lipid ROS levels and reduce Nrf2, GPX4, HO-1, and FSP1 protein expressions in H9C2 cells with H/R injury, but its effects were significantly attenuated by treatment with Fer-1. CONCLUSIONS Neu5Ac exacerbates ferroptosis of myocardial cells with H/R injury by inhibiting the Nrf2 axis to promote the production of ROS and lipid ROS.
Ferroptosis/drug effects* ; Myocytes, Cardiac/cytology* ; Animals ; NF-E2-Related Factor 2/metabolism* ; Rats ; N-Acetylneuraminic Acid/pharmacology* ; Cell Hypoxia ; Reactive Oxygen Species/metabolism* ; Cell Line ; Myocardial Reperfusion Injury/metabolism*

OBJECTIVES: To explore the mechanism that mediate the therapeutic effect of quercetin on heart failure. METHODS: We searched the TCMSP and Swiss ADME databases for the therapeutic targets of quercetin and retrieved heart failure targets from the Genecards and OMIM databases. The intersecting targets were analyzed with GO and KEGG pathway analysis using DAVID database, and the key genes were identified via PPI analysis. Molecular docking between the core targets and quercetin was performed using PyMOL and AutoDock Tools. In a heart failure model established in H9C2 cardiomyocytes by treatment with isoproterenol, the effect of quercetin on the expressions of the MAPK signaling pathway was tested. RESULTS: A total of 60 intersecting targets were identified. Enrichment analysis revealed that quercetin may inhibit heart failure through the MAPK signaling pathway. The core genes, including AMPK3 and BCL-2, were identified as potential key regulators in quercetin-mediated improvement of heart failure. Cellular experiments demonstrated that quercetin significantly reduced isoproterenol-induced apoptosis of cardiomyocytes in a dose-dependent manner and obviously decreased the Bax/Bcl-2 ratio and the expression levels of caspase-3, ERK and p38 in the cells. CONCLUSIONS Quercetin improves heart failure possibly by inhibiting cardiomyocyte apoptosis through the MAPK signaling pathway.
Quercetin/pharmacology* ; Myocytes, Cardiac/drug effects* ; Heart Failure/metabolism* ; Apoptosis/drug effects* ; MAP Kinase Signaling System/drug effects* ; Rats ; Animals ; Isoproterenol

OBJECTIVES: To investigate the effects of quercetin on cuproptosis and L-type calcium currents in the myocardium of diabetic rats. METHODS: Forty SD rats were randomized into control group and diabetic model groups. The rat models of diabetes mellitus (DM) induced by high-fat and high-sugar diet combined with streptozotocin (STZ) injection were further divided into DM model group, quercetin treatment group, and empagliflozin treatment group (n=10). Blood glucose and body weight were measured every other week, and cardiac function of the rats was evaluated using echocardiography. HE staining, Sirius red staining, and wheat germ agglutinin (WGA) analysis were used to observe the changes in myocardial histomorphology, and serum copper levels and myocardial FDX1 expression were detected. In cultured rat cardiomyocyte H9c2 cells with high-glucose exposure, the effects of quercetin and elesclomol, alone or in combination, on intracellular CK-MB and LDH levels and FDX1 expression were assessed, and the changes in L-type calcium currents were analyzed using patch-clamp technique. RESULTS: The diabetic rats exhibited elevated blood glucose, reduced body weight, impaired left ventricular function, increased serum copper levels and myocardial FDX1 expression, decreased L-type calcium currents, and prolonged action potential duration. Quercetin and empagliflozin treatment significantly lowered blood glucose, improved body weight, and restored cardiac function of the diabetic rats, and compared with empagliflozin, quercetin more effectively reduced serum copper levels, downregulated FDX1 expression, and enhanced myocardial L-type calcium currents in diabetic rats. In H9c2 cells, high glucose exposure significantly increased myocardial expressions of FDX1, CK-MB and LDH, which were effectively lowered by quercetin treatment; Elesclomol further elevated FDX1, CK-MB and LDH levels in the exposed cells, and these changes were not significantly affected by the application of quercetin. CONCLUSIONS Quercetin ameliorates myocardial injury in diabetic rats possibly by suppressing myocardial cuproptosis signaling and restoring L-type calcium channel activity.
Animals ; Quercetin/pharmacology* ; Calcium Channels, L-Type/metabolism* ; Diabetes Mellitus, Experimental/metabolism* ; Rats, Sprague-Dawley ; Rats ; Myocytes, Cardiac/drug effects* ; Myocardium/pathology* ; Male

OBJECTIVES: To explore the mechanism of Circ-MYOCD back-splicing and its regulatory role in myocardial hypertrophy. METHODS: Sanger sequencing and RNase R assays were performed to verify the circularity and stability of Circ-MYOCD, whose subcellular distribution was determined by nuclear-cytoplasmic fractionation. Bioinformatics analysis and mass spectrometry from pull-down assays were conducted to predict the RNA-binding proteins (RBPs) interacting with Circ-MYOCD. In rat cardiomyocytes H9C2 cells, the effects of HNRNPH1 and HNRNPL knockdown and overexpression on Circ-MYOCD back-splicing were evaluated. In a H9C2 cell model of angiotensin II (Ang II)-induced myocardial hypertrophy, the expression of HNRNPH1 was detected, the effects of HNRNPH1 knockdown and overexpression on progression of myocardial hypertrophy were assessed, and the regulatory effect of HNRNPH1 on Circ-MYOCD back-splicing was analyzed. RESULTS: Sanger sequencing confirmed that the junction primers could amplify the correct Circ-MYOCD sequence. RNase R and nuclear-cytoplasmic fractionation assays showed that Circ-MYOCD was stable and predominantly localized in the cytoplasm. Bioinformatics analysis and mass spectrometry from the Circ-MYOCD pull-down assay identified HNRNPH1 and HNRNPL as the RBPs interacting with Circ-MYOCD. In H9C2 cells, HNRNPH1 knockdown significantly enhanced while its overexpression inhibited Circ-MYOCD back-splicing; HNRNPH1 overexpression obviously increased the expressions of myocardial hypertrophy markers ANP and BNP, while its knockdown produced the opposite effect. In Ang II-induced H9C2 cells, which exhibited a significant increase of HNRNPH1 expression and increased expressions of ANP and BNP, HNRNPH1 knockdown obviously increased Circ-MYOCD expression, decreased MYOCD expression and lowered both ANP and BNP expressions. CONCLUSIONS HNRNPH1 regulates Circ-MYOCD back-splicing to influence the progression of myocardial hypertrophy.
Animals ; Rats ; RNA, Circular/genetics* ; Cardiomegaly/metabolism* ; Myocytes, Cardiac/metabolism* ; Heterogeneous-Nuclear Ribonucleoprotein Group F-H/metabolism* ; Cell Line ; RNA Splicing ; Angiotensin II ; RNA-Binding Proteins

OBJECTIVES: To investigate the effect of cardiomyocytes-derived exosomes on lipopolysaccharide (LPS)-induced cardiomyocyte injury and its mechanism. METHODS: Exosomes isolated from rat cardiomyocytes with or without LPS treatment were co-cultured with rat lymphocytes. The lymphocytes with or without exosome treatment were co-cultured with LPS-induced rat cardiomyocytes for 48 h. Cardiomyocyte apoptosis was detected using flow cytometry, and the expressions of apoptosis marker proteins and the PI3K/AKT pathway proteins were detected using Western blotting. The effects of human recombinant IL-38 protein on apoptosis and protein expressions in LPS-induced cardiomyocytes were examined. RESULTS: Compared with normal cardiomyocyte-derived exosomes, the exosomes from LPS-induced cardiomyocytes significantly enhanced proliferation and increased mRNA and protein expression levels of IL-38 in rat lymphocytes. Bioinformatics analysis suggested that miR-1275 in the exosome played a key role in LPS-induced cardiomyocyte injury, and in dual luciferase reporter gene assay, miR-1275 mimics significantly increased luciferase activity of WT-IL-38. Co-culture with lymphocytes treated with exosomes from LPS-induced cardiomyocytes significantly inhibited apoptosis of LPS-induced cardiomyocytes. Treatment with recombinant IL-38 also effectively lowered apoptosis rate of LPS-induced cardiomyocytes, reduced cellular expression of Bax protein, and increased the protein expression levels of Bcl-2, p-PI3K and p-AKT. CONCLUSIONS miR-1275 in exosomes derived from LPS-induced cardiomyocytes mediates IL-38 up-regulation expression in lymphocytes to activate the PI3K/AKT pathway and inhibit LPS-induced cardiomyocyte apoptosis.
Apoptosis/drug effects* ; MicroRNAs/metabolism* ; Myocytes, Cardiac/metabolism* ; Animals ; Lipopolysaccharides ; Rats ; Exosomes/metabolism* ; Up-Regulation ; Interleukins/metabolism* ; Lymphocytes/cytology* ; Cells, Cultured ; Signal Transduction ; Coculture Techniques ; Phosphatidylinositol 3-Kinases/metabolism* ; Rats, Sprague-Dawley ; Humans ; Proto-Oncogene Proteins c-akt/metabolism*