SUMO1 regulates post-infarct cardiac repair based on cellular heterogeneity / 药物分析学报

Small ubiquitin-related modifier(SUMOylation)is a dynamic post-translational modification that maintains cardiac function and can protect against a hypertrophic response to cardiac pressure overload.However,the function of SUMOylation after myocardial infarction(MI)and the molecular details of heart cell responses to SUMO1 deficiency have not been determined.In this study,we demonstrated that SUMO1 protein was inconsistently abundant in different cell types and heart regions after MI.However,SUMO1 knockout significantly exacerbated systolic dysfunction and infarct size after myocardial injury.Single-nucleus RNA sequencing revealed the differential role of SUMO1 in regulating heart cells.Among cardiomyocytes,SUMO1 deletion increased the Nppa+Nppb+Ankrd1+cardiomyocyte subcluster pro-portion after MI.In addition,the conversion of fibroblasts to myofibroblasts subclusters was inhibited in SUMO1 knockout mice.Importantly,SUMO1 loss promoted proliferation of endothelial cell subsets with the ability to reconstitute neovascularization and expressed angiogenesis-related genes.Computational analysis of ligand/receptor interactions suggested putative pathways that mediate cardiomyocytes to endothelial cell communication in the myocardium.Mice preinjected with cardiomyocyte-specific AAV-SUMO1,but not the endothelial cell-specific form,and exhibited ameliorated cardiac remodeling following MI.Collectively,our results identified the role of SUMO1 in cardiomyocytes,fibroblasts,and endothelial cells after Ml.These findings provide new insights into SUMO1 involvement in the patho-genesis of MI and reveal novel therapeutic targets.

Effect of sodium fluoride on myocardial damage by regulating apoptosis through JNK signaling pathway / 环境与职业医学

Background It has been found that fluoride may cause cardiomyocyte damage. c-Jun N-terminal kinases (JNK) signaling pathway plays an important role in apoptosis, but its role in fluorosis-induced cardiomyocyte damage is still unknown yet. Objective To explore the toxic effect of sodium fluoride (NaF) on H9c2 cardiomyocytes of rats and whether NaF affects cardiomyocyte apoptosis through the JNK signaling pathway. Methods According to the concentrations of sodium fluoride and whether sp600125 (JNK inhibitor) was added, cardiomyocytes of rats were divided into six groups, including control group, SP600125 group (SP group), 0.24, 0.48, and 0.96 mmol·L−1 NaF groups, and 0.96 mmol·L−1 NaF+SP600125 group (NaF+SP group). Cardiomyocytes exposed to NaF for 24 h were observed using a fluorescence inverted microscope. The changes of cell viability at 24, 48, and 72 h after the treatment were detected by CCK-8 method. The levels of reactive oxygen species (ROS) at 24 h after the treatment in H9c2 cardiomyocytes were determined by fluorescent probe method. The expression levels of Bcl-2, Bax, Caspase-3, and JNK mRNA at 24 h after the treatment were detected by real-time PCR. The protein expression levels of Bcl-2, Bax, Caspase-3, and p-JNK at 24 h after the treatment were detected by Western blotting. Results Compared with the control group, after being exposed to 0.48 and 0.96 mmol·L−1 NaF for 24 h, the cell growth density decreased. With the increase of NaF concentration, rounded cells and some suspended dead cells appeared. At 24h after exposure to NaF, the cell viability of the 0.48 and 0.96 mmol·L−1 NaF groups decreased compared with the control group (P<0.05). At 48h and 72h after exposure to NaF, the cell viability levels of the NaF treated groups were significantly lower than that of the control group (P<0.05). After NaF exposure for 24 h, compared with the control group, the intracellular ROS levels were increased (P<0.05); the mRNA expression levels of Bcl-2 were decreased to varying degrees, especially in the 0.48 and 0.96 mmol·L−1 NaF groups (P<0.05); the mRNA expression levels of Bax, Caspase-3, and JNK were increased (P<0.05); the protein expression levels of Bcl-2 were reduced (P<0.05); the protein expression levels of Bax, Caspase-3, and p-JNK were elevated (P<0.05). Compared with the 0.96 mmol·L−1 NaF group, the cell viability of the NaF+SP group was increased, the intracellular ROS level was decreased, the mRNA expression levels of Bax, Caspase-3, and JNK were decreased, the protein expression level of Bcl-2 was increased, and the protein expression levels of Bax, Caspase-3, and p-JNK were decreased (P<0.05); the expression level of Bcl-2 mRNA had a rising trend but showed no statistical significance (P>0.05). Conclusion Cardiomyocyte damage after excessive fluoride exposure may result from fluoride inducing excessive ROS production in cardiomyocytes, which may activate the JNK signaling pathway and induce cardiomyocyte apoptosis.

Single-nucleus transcriptomics reveals a gatekeeper role for FOXP1 in primate cardiac aging

Aging poses a major risk factor for cardiovascular diseases, the leading cause of death in the aged population. However, the cell type-specific changes underlying cardiac aging are far from being clear. Here, we performed single-nucleus RNA-sequencing analysis of left ventricles from young and aged cynomolgus monkeys to define cell composition changes and transcriptomic alterations across different cell types associated with age. We found that aged cardiomyocytes underwent a dramatic loss in cell numbers and profound fluctuations in transcriptional profiles. Via transcription regulatory network analysis, we identified FOXP1, a core transcription factor in organ development, as a key downregulated factor in aged cardiomyocytes, concomitant with the dysregulation of FOXP1 target genes associated with heart function and cardiac diseases. Consistently, the deficiency of FOXP1 led to hypertrophic and senescent phenotypes in human embryonic stem cell-derived cardiomyocytes. Altogether, our findings depict the cellular and molecular landscape of ventricular aging at the single-cell resolution, and identify drivers for primate cardiac aging and potential targets for intervention against cardiac aging and associated diseases.

Two new isoquinoline alkaloids from Corydalis hendersonii / 中国中药杂志

Corydalis hendersonii(CH) is a Tibetan folk medicine with the functions of clearing heat, detoxifying, cooling blood, checking diarrhea, and lowering blood pressure. It is often used to treat high altitude polycythemia, vasculitis, peptic ulcer, and diarrhea. Nine compounds were separated from the ethanol extract of CH by silica gel, ODS, Sephadex LH-20 chromatography and semi-preparative HPLC. Their structures were identified as hendersine H(1),hendersine I(2), dehydrocheilanthifoline(3), protopine(4), izmirine(5), 6,7-methylenedioxy-1(2H)-isoquinolinone(6), icariside D_2(7), ethyl 4-(β-D-glucopyranosyloxy)-3-methoxybenzoate(8), 3-hydroxy-4-methoxybenzoic acid(9), respectively, by the spectroscopic data analysis and comparison with those in the literature. Among them, compounds 1 and 2 are new isoquinoline alkaloids, and compounds 7-9 are reported the first time for Corydalis. The hypoglycemic model of H9c2 cardiomyocytes and the inflammatory model of H9c2 cardiomyocytes induced by conditional supernatant were employed to determine the activities of the above compounds. The results showed that 20 μmol·L~(-1) compound 1 had a protective effect on H9c2 cardiomyocytes and 10 μmol·L~(-1) compounds 4 and 5 inhibited H9c2 cardiomyocyte inflammation induced by conditional supernatant.

MicroRNA-22-3p Regulates the Expression of Kruppel-like Factor 6 to Affect the Cardiomyocyte-like Differentiation of Bone Marrow Mesenchymal Stem Cell / 中国医学科学院学报

Objective To explore the effect of microRNA-22-3p (miR-22-3p) regulating the expression of Kruppel-like factor 6 (KLF6) on the cardiomyocyte-like differentiation of bone marrow mesenchymal stem cell (BMSC). Methods Rat BMSC was isolated and cultured,and the third-generation BMSC was divided into a control group,a 5-azacytidine(5-AZA)group,a mimics-NC group,a miR-22-3p mimics group,a miR-22-3p mimics+pcDNA group,and a miR-22-3p mimics+pcDNA-KLF6 group.Real-time fluorescent quantitative PCR (qRT-PCR) was carried out to determine the expression of miR-22-3p and KLF6 in cells.Immunofluorescence staining was employed to detect the expression of Desmin,cardiac troponin T (cTnT),and connexin 43 (Cx43).Western blotting was employed to determine the protein levels of cTnT,Cx43,Desmin,and KLF6,and flow cytometry to detect the apoptosis of BMSC.The targeting relationship between miR-22-3p and KLF6 was analyzed by dual luciferase reporter gene assay. Results Compared with the control group,5-AZA up-regulated the expression of miR-22-3p (q=7.971,P<0.001),Desmin (q=7.876,P<0.001),cTnT (q=10.272,P<0.001),and Cx43 (q=6.256,P<0.001),increased the apoptosis rate of BMSC (q=12.708,P<0.001),and down-regulated the mRNA (q=20.850,P<0.001) and protein (q=11.080,P<0.001) levels of KLF6.Compared with the 5-AZA group and the mimics-NC group,miR-22-3p mimics up-regulated the expression of miR-22-3p (q=3.591,P<0.001;q=11.650,P<0.001),Desmin (q=5.975,P<0.001;q=13.579,P<0.001),cTnT (q=7.133,P<0.001;q=17.548,P<0.001),and Cx43 (q=4.571,P=0.037;q=11.068,P<0.001),and down-regulated the mRNA (q=7.384,P<0.001;q=28.234,P<0.001) and protein (q=4.594,P=0.036;q=15.945,P<0.001) levels of KLF6.The apoptosis rate of miR-22-3p mimics group was lower than that of 5-AZA group (q=8.216,P<0.001).Compared with the miR-22-3p mimics+pcDNA group,miR-22-3p mimics+pcDNA-KLF6 up-regulated the mRNA(q=23.891,P<0.001) and protein(q=13.378,P<0.001)levels of KLF6,down-regulated the expression of Desmin (q=9.505,P<0.001),cTnT (q=10.985,P<0.001),and Cx43 (q=8.301,P<0.001),and increased the apoptosis rate (q=4.713,P=0.029).The dual luciferase reporter gene experiment demonstrated that KLF6 was a potential target gene of miR-22-3p. Conclusion MiR-22-3p promotes cardiomyocyte-like differentiation of BMSC by inhibiting the expression of KLF6.

Trastuzumab-induced human cardiomyocyte damage through the Notch2/JAK2/STAT3 pathway

Abstract Objective Trastuzumab is the preferred drug for the treatment of breast cancer. However, research on the cellular mechanisms of trastuzumab's potential cardiotoxicity is insufficient. The purpose of this study was to explore the toxic effects and potential mechanism of action of trastuzumab on cardiomyocytes. Method Human Cardiomyocyte (HCM) viability was assessed using the MTT method. HCM apoptosis was detected using the Hoechst33342/PI Fluorescent staining. The LDH and CK activities of the cell were measured using commercially available LDH and CK assay kits. The expression levels of Notch2, JAK2, STAT3, cleaved caspase 3, bax, and bcl 2 in HCMs were detected using western blotting. Results The results showed that 250 mg/L trastuzumab induced cardiomyocyte injury and apoptosis, inhibited viability, activated the Notch2 receptor, and inhibited JAK2/STAT3 expression in HCM. Inhibition of Notch2 expression in HCM by targeted siNotch2 transfection reversed the trastuzumab-induced injury and apoptosis, and the expression of JAK2/STAT3 returned to normal levels. Conclusions Trastuzumab induces Notch2 expression by inhibiting the JAK2/STAT3 pathway of HCMs, promotes cell apoptosis, and causes cardiomyocyteinjury. Notch2 may be a potential target of trastuzumab-inducedmyocardial injury. This experiment reveals the mechanism of trastuzumab-induced cardiotoxicity, providing a theoretical basis for the application of trastuzumab.

The role of Vav3 expression for inflammation and cell death during experimental myocardial infarction

Abstract Objectives Myocardial Infarction (MI) is the leading cause of chronic heart failure. Previous studies have suggested that Vav3, a receptor protein tyrosine kinase signal transducer, is associated with a variety of cellular signaling processes such as cell morphology regulation and cell transformation with oncogenic activity. However, the mechanism of Vav3-mediated MI development requires further investigation. Method Here, The authors established an MI rat model by ligating the anterior descending branch of the left coronary artery, and an MI cell model by treating cardiomyocytes with H2O2. Microarray analysis was conducted to identify genes with differential expression in heart tissues relevant to MI occurrence and development. Vav3 was thus selected for further investigation. Results Vav3 downregulation was observed in MI heart tissue and H2O2-treated cardiomyocytes. Administration of Lentiviral Vav3 (LV-VAV3) in MI rats upregulated Vav3 expression in MI heart tissue. Restoration of Vav3 expression reduced infarct area and ameliorated cardiac function in MI rats. Cardiac inflammation, apoptosis, and upregulation of NFκB signal in heart tissue of MI animals were assessed using ELISA, TUNEL staining, real-time PCR, and WB. Vav3 overexpression reduced cardiac inflammation and apoptosis and inhibited NFκB expression and activation. Betulinic Acid (BA) was then used to re-activate NFκB in Vav3-overexpressed and H2O2-induced cardiomyocytes. The expression of P50 and P65, as well as nuclear P65, was significantly increased by BA exposure. Conclusions Vav3 might serve as a target to reduce ischemia damage by suppressing the inflammation and apoptosis of cardiomyocytes.

Propofol inhibits myocardial injury induced by microvesicles derived from hypoxiareoxygenated endothelial cells via lncCCT4-2/CCT4 signaling

Background Ischemia-reperfusion (IR) induces increased release of extracellular vesicles in the heart and exacerbates myocardial IR injury. We have previously shown that propofol attenuates hypoxia/reoxygenation (HR)-induced injury in human umbilical vein endothelial cells (HUVECs) and that microvesicles derived from propofol-treated HUVECs inhibit oxidative stress in endothelial cells. However, the role of microvesicles derived from propofol post-treated HUVECs ((HR + P)-EMVs) in IR-injured cardiomyocytes is unclear. In this study, we aimed to investigate the role of (HR + P)-EMVs in cardiac IR injury compared to microvesicles derived from hypoxic/reoxygenated HUVECs (HR-EMVs) and to elucidate the underlying mechanisms. Methods Hypoxia/reoxygenation (HR) models of HUVECs and AC16 cells and a mouse cardiac IR model were established. Microvesicles from HR-injured HUVECs, DMSO post-treated HUVECs and propofol post-treated HUVECs were extracted by ultra-high speed centrifugation, respectively. The above EMVs were co-cultured with HR-injured AC16 cells or injected intracardially into IR mice. Flow cytometry and immunofluorescence were used to determine the levels of oxidative stress and apoptosis in cardiomyocytes. Apoptosis related proteins were detected by Western blot. Echocardiography for cardiac function and Evans blue-TTC staining for myocardial infarct size. Expression of lncCCT4-2 in EMVs and AC16 cells was analysed by whole transcriptome sequencing of EMVs and RT-qPCR. The molecular mechanism of inhibition of myocardial injury by (HR + P)-EMVs was elucidated by lentiviral knockdown of lncCCT4-2, plasmid overexpression or knockdown of CCT4, and actinomycin D assay. Results In vitro and in vivo experiments confirmed that HR-EMVs exacerbated oxidative stress and apoptosis in IR-injured cardiomyocytes, leading to increased infarct size and worsened cardiac function. Notably, (HR + P)-EMVs induced significantly less oxidative stress and apoptosis in IR-injured cardiomyocytes compared to HR-EMVs. Mechanistically, RNA sequencing of EMVs and RT-qPCR showed that lncCCT4-2 was significantly upregulated in (HR + P)-EMVs and cardiomyocytes co-cultured with (HR + P)-EMVs. Reduction of lncCCT4-2 in (HR + P)-EMVs enhanced oxidative stress and apoptosis in IR-injured cardiomyocytes. Furthermore, the anti-apoptotic activity of lncCCT4-2 from (HR + P)-EMVs was achieved by increasing the stability of CCT4 mRNA and promoting the expression of CCT4 protein in cardiomyocytes. Conclusions Our study showed that (HR + P)-EMVs uptake by IR-injured cardiomyocytes upregulated lncCCT4-2 in cardiomyocytes and promoted CCT4 expression, thereby inhibiting HR-EMVs induced oxidative stress and apoptosis. Highlights Microvesicles from hypoxic/reoxygenated HUVECs (HR-EMVs) exacerbated oxidative stress and apoptosis in IR-injured cardiomyocytes. Microvesicles from propofol post-treated HUVECs ((HR + P)-EMVs) induced diminished oxidative stress and apoptosis in IR-injured cardiomyocytes compared with microvesicles from hypoxic/reoxygenated HUVECs (HR-EMVs). lncCCT4-2 was significantly highly expressed in (HR + P)-EMVs and cardiomyocytes co-cultured with (HR + P)-EMVs, and reduction of lncCCT4-2 in (HR + P)-EMVs enhanced oxidative stress and apoptosis in IR-injured cardiomyocytes. lncCCT4-2 inhibited HR-EMVs induced oxidative stress and apoptosis in HR-injured AC16 cells by increasing the stability of CCT4 mRNA and promoting the expression of CCT4 protein in AC16 cells.

Cardiomyocyte Energy Metabolism in Mammalian Cardiac Regeneration / 中山大学学报(医学科学版)

Cardiovascular disease， such as coronary heart disease and acute myocardial infarction， is a leading cause of death globally. Due to the limited proliferative and regenerative capacity of adult mammalian cardiomyocytes （CMs）， any of the current therapies cannot reverse the massive loss of CMs and subsequent fibrosis resulting from cardiac injury. Mammals mainly rely on glycolysis in the embryonic stage and fatty acid oxidation after birth for energy production. Recent reports have indicated that this metabolic pattern switch is closely related to the loss of CM proliferation. In this review， we summarize the biological characteristics of CMs and advances in heart regeneration， meanwhile shed light on the important role of CMs energy metabolism in cardiac regeneration.

Effect of asiaticoside on OGD/R induced injury of H9C2 cardiomyocytes based on PI3K/Akt/Beclin-1 signaling pathway / 药学学报

In order to investigate the effects of asiaticoside (Ass) on H9C2 cardiomyocytes, the present study examined the potential intervention of Ass on the proliferation and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/Bcl-2 homology domain protein (Beclin-1) signaling pathway in H9C2 cardiomyocytes following oxygen and glucose deprivation/reperfusion (OGD/R) injury. H9C2 cardiomyocytes were selected as the research objects, and the activity of H9C2 was detected by cell counting kit-8 (CCK-8). H9C2 cells were divided into control group, OGD/R group, Ass low concentration group (10 μmol·L-1), Ass high concentration group (80 μmol·L-1) and Ass high concentration + chloroquine group (80 μmol·L-1 + 50 μmol·L-1). The control group was cultured under normal conditions, and the other groups were treated with oxygen and glucose deprivation for 4 h and reperfusion for 2 h. The activity and content of aspartic aminotransferase (AST), lactate dehydrogenase (LDH) and creatine kinase (CK) in the supernatant of H9C2 cardiomyocytes were detected by enzyme-linked immunosorbent assay. Autophagy staining assay kit with monodansylcadaverine (MDC) method to observe cellular autophagy; molecular docking technique to identify the molecular targets of Ass. Immunofluorescence was used to observe the effect of the drug on cell number. The expression levels of PI3K, Akt, selective autophagy adaptor protein (P62) and Beclin-1 were detected by Western blot. Compared with OGD/R group, Ass group had a protective effect from 10-80 μmol·L-1, and the activities and contents of AST, LDH and CK were decreased. The protein expression levels of PI3K, Akt, P62 and Beclin-1 were decreased. Compared with the administration group, the activities and contents of AST, LDH and CK in Ass high-concentration + chloroquine group were significantly decreased, and the protein expression levels of PI3K, Akt, Beclin-1 and P62 were significantly decreased. Immunofluorescence showed that the inhibitor group and each administration group had different degrees of protective effect compared with the model group. Asiaticoside can reduce the injury of H9C2 cardiomyocyte induced by OGD/R, reduce the content of AST, LDH and CK, reduce the expression level of P62 protein, and reduce autophagy, which may be closely related to the inhibition of PI3K/Akt/Beclin-1 signaling pathway activation.

miR-148a-3p improves mitochondrial injury and apoptosis induced by high-glucose through inhibiting CRT expression / 西安交通大学学报(医学版)

【Objective】 To evaluate the effects of miR-148a-3p on calreticulin (CRT) expression and mitochondrial function in cardiomyocytes incubated with high glucose. 【Methods】 miR-148a-3p minic and inhibitor were used to intervene the H9c2 cardiomyocytes of rats. The expression of CRT protein was detected. Then the cells were divided into control group, high-glucose group (HG), HG +miR-148a-3p minic group, HG + miR-148a-3p minic + TG (CRT agonist) group, HG + miR-148a-3p inhibitor group, and HG + miR-148a-3p inhibitor + CRT- (CRT-siRNA) group. The content of adenosine triphosphate (ATP) and the level of reactive oxygen species (ROS), the activity of mitochondrial respiratory chain complex enzyme and apoptotic rate were detected. 【Results】 miR-148a-3p minic significantly inhibited the expression of CRT protein in cardiomyocytes, while miR-148a inhibitor increased the expression of CRT. miR-148a-3p minic inhibited the decrease of ATP production, the increase of ROS production and cell apoptosis, and the inactivity of mitochondrial respiratory chain complex enzyme in cardiomyocytes induced by high glucose, while TG weakened the above effects of miR-148a-3p minic. miR-148a inhibitor aggravated the mitochondrial injury and apoptosis of cardiomyocytes induced by high glucose, but the effects of miR-148a-3p inhibitor were partially blocked by CRT-siRNA. 【Conclusion】 miR-148a-3p negatively regulates the expression of CRT in cardiomyocytes and protects the mitochondrial injury and apoptosis induced by high-glucose through inhibiting CRT.

Formononetin regulates dilated cardiomyopathy-mediated heart failure in rats via HSP90/AKT cardiomyocyte apoptosis and mechanism / 西安交通大学学报(医学版)

【Objective】 To investigate the effects of formononetin (FMN) on cardiomyocyte apoptosis and HSP90/AKT in rats with dilated cardiomyopathy-mediated heart failure. 【Methods】 Echocardiography, ELISA, histological staining, and TUNEL staining were used to observe the protective effect of different doses of FMN on dilated cardiomyopathy-mediated heart failure in rats and the apoptosis of cardiomyocytes. The potential targets of formononetin on dilated cardiomyopathy-mediated heart failure were obtained from TCMSP, DisGeNet, GeneCards, and other databases, the key targets were obtained according to the protein-protein interaction (PPI) network, and the key targets were verified by molecular docking. Western blotting was used to further verify the regulatory role of key targets in the treatment of dilated cardiomyopathy-mediated heart failure with formononetin. 【Results】 Formononetin could reduce the levels of LVIDS, LVIDD, NT-pro BNP, cTn-T, CK, CK-MB, and LDH in rats with dilated cardiomyopathy-mediated heart failure, increase the levels of EF and FS, and reduce the apoptosis of cardiomyocytes. FMN had a strong binding effect on 10 key targets (AKT1, HSP90AA1, CASP3, MAPK1, MMP9, SRC, ALB, HRAS, IGF1, and EGFR) screened by network pharmacology, with HSP90AA1 and AKT1 having the strongest binding effect. Formononetin decreased the expression of HSP90, AKT and downstream CASP3 protein, but increased the expression of p-AKT in myocardial tissue. 【Conclusion】 Formononetin may inhibit the expression of HSP90, promote phosphorylation of AKT to p-AKT, and inhibit the expression of CASP3, thereby reducing the apoptosis of cardiomyocytes and improving myocardial tissue damage, so as to achieve the purpose of treating dilated cardiomyopathy-mediated heart failure.

Renewal of embryonic and neonatal-derived cardiac-resident macrophages in response to environmental cues abrogated their potential to promote cardiomyocyte proliferation via Jagged-1-Notch1

Cardiac-resident macrophages (CRMs) play important roles in homeostasis, cardiac function, and remodeling. Although CRMs play critical roles in cardiac regeneration of neonatal mice, their roles are yet to be fully elucidated. Therefore, this study aimed to investigate the dynamic changes of CRMs during cardiac ontogeny and analyze the phenotypic and functional properties of CRMs in the promotion of cardiac regeneration. During mouse cardiac ontogeny, four CRM subsets exist successively: CX3CR1+CCR2-Ly6C-MHCII- (MP1), CX3CR1lowCCR2lowLy6C-MHCII- (MP2), CX3CR1-CCR2+Ly6C+MHCII- (MP3), and CX3CR1+CCR2-Ly6C-MHCII+ (MP4). MP1 cluster has different derivations (yolk sac, fetal liver, and bone marrow) and multiple functions population. Embryonic and neonatal-derived-MP1 directly promoted cardiomyocyte proliferation through Jagged-1-Notch1 axis and significantly ameliorated cardiac injury following myocardial infarction. MP2/3 subsets could survive throughout adulthood. MP4, the main population in adult mouse hearts, contributed to inflammation. During ontogeny, MP1 can convert into MP4 triggered by changes in the cellular redox state. These findings delineate the evolutionary dynamics of CRMs under physiological conditions and found direct evidence that embryonic and neonatal-derived CRMs regulate cardiomyocyte proliferation. Our findings also shed light on cardiac repair following injury.

Effects of ginkgolide B on Caspase-3/PTEN/Akt pathway and cell proliferation and apoptosis in hypoxia/reoxygenation cardiomyocytes / 中国胸心血管外科临床杂志

@#Objective     To investigate the effect of ginkgolide B (GB) on cysteinyl aspartate specific proteinase-3 (Caspase-3)/chromosome 10 deletion phosphatase-tension protein homologue (PTEN)/protein kinase B (Akt) pathway and cell proliferation and apoptosis in hypoxia/reoxygenation cardiomyocytes. Methods     H9C2 cells were cultured in vitro. A control group was cultured in serum-free DMEM high glucose medium at 37°C and 5% CO2 for 28 hours. The remaining groups were prepared with hypoxia/reoxygenation models. A GB low-dose group and a GB high-dose group were treated with GB pretreatment with final concentration of 50 μmol/L and 200 μmol/L respectively at 1 h before hypoxia/reoxygenation. A carvedilol group was treated with carvedilol of a final concentration of 10 μmol/L at 1 h before hypoxia/reoxygenation. The proliferation and apoptosis of H9C2 cells were detected, and the levels of lactate dehydrogenase (LDH), malondialdehyde (MDA), reactive oxygen species (ROS), PTEN, Akt, phosphorylated Akt (p-Akt) and Caspase-3 in H9C2 cells were also detected. Results     Compared with the control group, the proliferation rate of H9C2 cell, and the levels of PTEN, Akt and p-Akt in other groups decreased, and the apoptosis rate, and the levels of LDH, MDA, ROS and Caspase-3 increased (P<0.05). Compared with the hypoxia/reoxygenation group, the proliferation rate of H9C2 cell, and the levels of PTEN, Akt and p-Akt in all GB dose groups and the carvedilol group increased; the apoptosis rate, and the levels of LDH, MDA, ROS and Caspase-3 decreased, and the effect of GB was in a dose dependent manner; however, the effect of GB was not as strong as carvedilol (P<0.05). Conclusion     GB can inhibit H9C2 cell apoptosis and promote H9C2 cell proliferation by activating Caspase-3/PTEN/Akt pathway.

Mechanism of Astragalus methylside alleviating cardiomyocyte hypertrophy / 中华老年医学杂志

Objective:To investigate the protective effects and related mechanisms of Astragaloside Ⅳ(ASⅣ)alleviating Angiotensin II-induced cardiomyocyte hypertrophy.Methods:H9c2 cardiomyocytes were divided into six groups: normal control group, ASⅣ group(ASⅣ 100 μmol/L), AngⅡ group(AngⅡ 1 μmol/L), and three ASⅣ dose experiments(AngⅡ 1 μmol/L + ASⅣ 25 μmol/l group, AngⅡ 1 μmol/L+ ASⅣ 50 μmol/l group, AngⅡ1 μmol/L+ ASⅣ 100 μmol/L group), and simultaneously cultured for 24 hours.Cardiomyocyte viability was assessed by CCK8 assay, and surface area of culturedcardiomyocytes in each group was assessed by immunofluorescence assay.Atrial natriuretic peptide(ANP)mRNA expression was assessed by fluorescence real-time quantitative RT-PCR.And LC3 protein expression, an autophagy related protein, was assessed by Western blotting as well as immunofluorescence.Results:(1)AngⅡ decreased cardiomyocyte H9c2 viability in a dose-dependent manner( P<0.05). ASⅣ could inhibit the decrease of cardiomyocyte H9c2 viability in response to AngⅡ in a dose-dependent manner( P<0.05). (2)H9c2 cardiomyocytes induced by AngⅡ showed a significantly larger cell area and significantly higher ANP mRNA and ANP protein expression compared with controls.Different concentrations of ASⅣ intervention could reverse the increase of cardiomyocyte H9c2 area induced by AngⅡ and also decreased the expression of ANP protein induced by AngⅡ in a dose-dependent manner(all P<0.05). (3)Compared with the control group, the autophagy level and the expression of autophagy marker LC3II/I of H9c2 cardiomyocytes induced by AngⅡ were significantly increased(all P<0.05). ASⅣ could inhibit AngⅡ-activated autophagy, and the difference was statistically significant( P<0.05). ASⅣ inhibited the expression of LC3II/I in H9c2 cardiomyocytes stimulated by AngⅡ, and the difference was statistically significant( P<0.05). Conclusions:ASⅣ inhibits AngⅡ-induced cardiac hypertrophy by inhibiting autophagy of cardiomyocytes.

Effects of acteoside on hypoxia/reoxygenation-induced cardiomyocyte damage by regulating the Rnd 3/NF-κB pathway / 中国药房

OBJECTIVE To explore the effects of acteoside on hypoxia/reoxygena tion（H/R）-induced cardiomyocyte damage by regulating Rho family GTPase 3（Rnd3）/nuclear factor κB（NF-κB）pathway. METHODS The H 9c2 cardiomyocyte were divided into control group （no administration ，no modeling ），H/R group （only modeling ），H/R+AS-L group ，H/R+AS-M group ， H/R+AS-H group （10，30，90 μmol/L acteoside for above 3 groups firstly ，and then modeling ），H/R+pcDNA group [transfecting pcDNA （empty vector ） firstly，and then modeling] ，H/R + pcDNA-Rnd 3 group [overexpression of Rnd 3 by transfecting pcDNA-Rnd3（Rnd3 overexpression vector ）firstly，and then modeling] ，H/R+AS-H+si-NC group [transfecting si-NC （negative control）firstly，and then giving 90 μmol/L acteoside and modeling]，H/R+AS-H+si-Rnd3 group [inhibiting overexpression of Rnd 3 by transfecting si-Rnd 3 （Rnd3 small interfering RNA ） firstly，and then giving 90 μ mol/L acteoside and modeling]. After corresponding treatment ，the apoptotic rate ，release of lactate dehydrogenase （LDH），malondialdehyde（MDA）level，the activity of superoxide dismutase （SOD），the level of tumor necrosis factor α（TNF-α），interleukin 1β（IL-1β）and interleukin- 6（IL-6）， mRNA and protein expression of Rnd 3 and NF-κB subunit p65（NF-κB p65），the expression of aspartate proteolytic enzyme 3 （Cleaved Caspase- 3）protein and Cleaved Caspase- 9 protein were detected. RESULTS Different concentrations of acteoside could reduce the apoptotic rate of H/R-induced H 9c2 cardiomyocyte，the protein expressions of Cleaved Caspase- 3 and Cleaved Caspase-9，mRNA and protein expressions of NF-κB p65，the levels of LDH release and MDA ，TNF-α，IL-1β and IL-6，while increase the activity of SOD and mRNA and protein expressions of Rnd 3（P＜0.05），in a dose-dependent manner. Overexpression of Rnd 3 could decrease the apoptotic rate of H 9c2 cardiomyocyte，protein expressions of NF-κB p65，Cleaved Caspase- 3 and Cleaved Caspase- 9， the levels of LDH release ， MDA， TNF-α，IL-1β and IL-6，while increase the protein expression of Rnd 3 and the activity of SOD （P＜0.05）. The inhibition overexpression of Rnd 3 could weaken the inhibitory effects of acteoside on H/R-induced apoptosis of H 9c2 cardiomyocyte， oxidative stress and inflammatory reaction （P＜0.05）. CONCLUSIONS Acteoside could regulate Rnd 3/NF-κ B pathway by promoting the expression of Rnd 3 and inhibiting the expression of NF-κB p65，inhibit cardiomyocyte apoptosis ，oxidative stress and inflammation reaction so as to relieve the H/R-induced cardiomyocyte damage.

Myocardial protective effect of Yangxin dingji capsule on diabetic cardiomyopathy model golden hamsters / 中国药房

OBJECTIVE To explore t he protective mechanism of Yangxin dingji capsules on the cardiomyocytes of diabetic cardiomyopathy（DCM）model golden hamsters. METHODS In this study ，golden hamsters were divided into control group （n＝ 10，no modeling ，no drug administration ），model group （n＝9，modeling，no drug administration ），TCM high-dose group [ n＝8， modeling，Yangxin dingji capsules 2 g/（kg·d）]，TCM low-dose group [ n＝8，modeling，Yangxin dingji capsules 1 g/（kg·d）] and empagliflozin group [ n＝9，positive control ，modeling，10 mg/（kg·d）]. All the golden hamsters were gavaged continuously for 8 weeks. The general conditions of golden hamsters were observed during the experiment. Blood glucose ，total cholesterol （TC）and creatine kinase MB （CK-MB），ejection fraction （EF），fractional shortening （FS），interleukin 1β（IL-1β）and transforming growth factor β1（TGF-β1）were detected ；the histopathological changes of myocardium were observed. mRNA and protein expression of nucleotide-binding oligomerization domain-like receptor protein 3（NLRP3），caspase-1，aspirin D （GSDMD），nuclear factor κB （NF-κB）and IL- 1β were detected and observed；DNA damage in myocardial was detected. RESULTS Compared with control group，the blood glucose ，TC，CK-MB，serum IL- 1β，TGF-β1 levels，the mRNA expressions and positive protein expression of NLRP 3，caspase-1，GSDMD，NF-κ B and IL-1 β and protein expression of GSDMD in golden hamsters were significantly increased in model group （P＜0.05 or P＜0.01） EF and FS were significantly decreased （P＜0.01）；the fibers of myocardial cells was disordered ， and the blue-stained collagen fibers between the myocardium increased ； DNA damaged positive cells in myocardial tiss ue of gold hamsters increased significantly. Compared with model group，the above indexes of administration groups were reversed to varying degrees ；the gap of myocardial cells were clear ，and the fibers disorder was improved ；the DNA damaged positive cells in the myocardial tissue were reduced to varying degrees. CONCLUSIONS Yangxin dingji capsule can inhibit the cardiomyocyte pyroptosis and relieve the inflammatory injury of DCM in DCM model golden hamsters by regulating the NLRP 3/caspase-1/GSDMD signaling pathway ，so as to protect the cardiomyocytes.

Qishen Huoxue granules containing serum can improve the damage of septic cardiomyocytes by inhibiting excessive autophagy / 中国医师杂志

Objective:To investigate the inhibitory effect of Qishen Huoxue granule containing serum on excessive autophagy of cardiomyocytes (H9c2) in septic rats and its protective effect on septic cardiomyocytes.Methods:Twelve SPF grade Wistar rats were gavaged with low, medium and high doses of Qishen Huoxue granule [equivalent to crude drugs 12.7, 25.4 and 50.8 g/(kg·d)]. The cultured rat embryonic cardiomyocytes (H9c2) were divided into five groups: the control group was cultured with DMEM containing 10% fetal bovine serum (FBS); lipopolysaccharide (LPS) group was treated with DMEM containing 10% FBS+ 1 μg/ml LPS; LPS+ Qishen Huoxue granule low, medium and high dose groups were pre intervened with DMEM containing 10% low, medium and high dose intragastric drug containing serum for 4 h, and then added 1 μg/ml LPS. After co-cultured for 4 h, the mRNA and protein expression of autophagy markers Beclin-1, ATG5 and LC3B were detected by real time fluorescence quantitative polymerase chain reaction (qRT-PCR) and Western blot; After 8, 12, 24 and 48 hours of co culture, the cell activity of cells in each group at different time points was detected by cell counting method (CCK-8) method.Results:The expression of autophagy markers Beclin-1, ATG5 mRNA and Beclin-1, ATG5 and LC3B protein in LPS group increased in the early stage (4 h), which was statistically significant compared with the control group ( P<0.05). However, LPS+ Qishen Huoxue granule groups could reduce the overexpression of Beclin-1, ATG5 and LC3B mRNA and protein caused by LPS ( P<0.05). CCK-8 method showed that the cell activity of LPS group LPS+ Qishen Huoxue granule low, medium and high dose groups decreased significantly at 12 h, 24 h and 48 h, which was significantly different from that of the control group ( P<0.05); The cell activity of LPS+ Qishen Huoxue granule medium dose group at 24 and 48 hours was significantly higher than that of LPS group ( P<0.05). Conclusions:The drug-containing serum of Qishen Huoxue granules at different concentrations had inhibitory effects on LPS-induced autophagy of cardiomyocytes, and the drug-containing serum obtained by intragastric administration of Qishen Huoxue granules in rats can improve the myocardial injury caused by sepsis by inhibiting autophagy.

Levosimendan alleviates coronary microembolization-induced myocardial injury through LOX-1/p38 MAPK pathway / 中华急诊医学杂志

Objective:To study the effect of levosimendan on coronary microembolization (CME)-induced myocardial injury and LOX-1/p38MAPK pathway.Methods:Microspheres were injected into coronary anterior descending branch to construct swine CME model, swine was given levosimendan by continuous intravenous drip for 24 h before modeling, and myocardial-specific overexpression of lectin-like oxidized low density lipoprotein receptor 1 (LOX-1) was achieved through coronary artery injection of adeno-associated virus (AAVs) at 2 weeks before modeling. Then, echocardiography was used to measure cardiac function; HE staining and HBFP staining were used to observe the pathological changes of myocardium and myocardial microinfarction area, respectively; ELISA was used to detect the serum level of cTnI; TUNLE staining was used to detect cardiomyocyte apoptotic index; the LOX-1, Bax, caspase-3 p12, Bcl-2, and p-p38 MAPK protein in myocardial tissue was observed by immunofluorescence method.Results:Compared to the sham group, the LVEF, LVFS, and CO value in the CME group were decreased, while the LVEDd value was increased significantly (all P<0.05); the area of myocardial micro-infarction, serum cTnI level and cardiomyocyte apoptotic rate in the CME group were increased significantly (all P<0.05); the protein levels of Bax, caspase-3 p12, LOX-1, and p-p38 MAPK were increased significantly, while the Bcl-2 level was decreased significantly ( P<0.05). Levosimendan pretreatment significantly improved cardiac dysfunction, reduced the area of myocardial micro-infarction and serum cTnI level, alleviated cardiomyocyte apoptosis, and significantly reduced the LOX-1 and p-p38 MAPK protein expression levels following CME (all P<0.05); while pretreatment with levosimendan and LOX-1 overexpression AAVs simultaneously abolished the effects of pretreatment with levosimendan alone (all P<0.05). Conclusion:Levosimendan alleviates CME-induced myocardial injury through inhibiting cardiomyocyte apoptosis mediated by LOX-1/p38 MAPK signaling pathway.

Cardiomyocyte-like differentiation of bone marrow mesenchymal stem cells induced by myocardial tissue lysates from different parts of the myocardium / 中国组织工程研究

BACKGROUND: Bone marrow mesenchymal stem cells can be induced into myocardial tissue-like structure in vitro. Myocardial tissue lysates from different parts of the myocardium can be used to construct differential microenvironments. Few studies have investigated the targeted induction efficiency of bone marrow mesenchymal stem cells and the expression of related genes. OBJECTIVE: To investigate the effects of lysates from different parts of the myocardium on the differentiation of bone marrow mesenchymal stem cells into myocardial tissue-like structures and to assess the correlation between the expressions of related genes during induction and myocardial tissue engineering. METHODS: Passage 3 bone marrow mesenchymal stem cells from Sprague-Dawley rats were cultured. Whole heart tissue lysate, atrial muscle tissue lysate, and ventricular muscle tissue lysate were used to construct different microenvironments to induce bone marrow mesenchymal stem cells to differentiate into cardiomyocyte-like cells. The morphological changes and ultrastructure of cells were observed with an inverted phase contrast microscope and transmission electron microscopy. Expression of α-actin and cTnI was detected by immunofluorescence staining. qRT-PCR was used to detect the expression of upstream molecules ANP, HCN4 and downstream molecules MLC-2v in the cAMP/PKA signaling pathway after induction. RESULTS AND CONCLUSION: (1) Each induction cell group followed similar morphological changes: Cardiomyocyte-like cells were capable of autonomic beats, rhythmic contractions and relaxations; under the transmission electron microscope, there were a large number of arranged myofilaments; immunofluorescent staining showed positive expression of α-actin and cTnI. (2) The whole heart tissue lysate was able to induce the differentiation of bone marrow mesenchymal stem cells into rice grain-sized myocardial tissue-like structures with collagen fibers. (3) Atrial muscle tissue lysate could induce bone marrow mesenchymal stem cells to differentiate into atrial muscle-like cells. Autonomic beats appeared earlier, but the beat frequency and duration were shorter. ANP and HCN4 were highly expressed in atrial myocytes. (4) Ventricular muscle tissue lysate induced bone marrow mesenchymal stem cells to differentiate into ventricular muscle-like cells with no secretory granules, and MLC-2v was highly expressed in ventricular muscle-like cells. (5) To conclude, the whole heart tissue lysate can induce bone marrow mesenchymal stem cells to form myocardial tissue-like structures. Atrial muscle tissue lysate can induce bone marrow mesenchymal stem cells to differentiate into atrial muscle-like cells. Ventricular muscle tissue lysate can induce bone marrow mesenchymal stem cells to differentiate into ventricular muscle-like cells. By constructing a specific microenvironment, bone marrow mesenchymal stem cells can be differentiated to cardiomyocytes in different parts, providing laboratory data for the construction of myocardial tissue engineering.