Effect of microparticles derived from bone marrow mesenchymal stem cells on cardiomyocyte hypertrophy and its mechanism / 中国生物制品学杂志

@#Objective To investigate the effect of microparticles(MPs)derived from bone marrow mesenchymal stem cells(BMSCs) on myocardial hypertrophy and its mechanism.Methods The osteogenic differentiation and adipogenic differentiation of mesenchymal stem cells(MSCs) were induced. After isolation and purification,the morphological characteristics were observed by transmission electron microscope,and the MPs surface antigen was identified by flow cytometry. Myocardial hypertrophy model was induced by using isoprenaline(ISO)in rats,which were measured for the cardiac structure and function by echocardiography,and then detected for various indexes of the heart and isolated left ventricle. Single ventricular myocytes of rats were acutely isolated and divided into control group(Control group),cardiomyocyte hypertrophy group(ISO group),MPs group(MPs group),and MPs supernatant group(Supernatant group). The mRNA expressions of atrial natriuretic peptide(ANP)and B-type natriuretic peptide(BNP)were detected by qRTPCR. The expression levels of calmodulin-dependent protein kinaseⅡ（CaMKⅡ）and phosphorylated calmodulin-dependent protein kinaseⅡ（p-CaMKⅡ）were detected by ELISA. The L-type calcium current(LCa-L)in single ventricular myocyte of various groups was recorded by whole-cell patch clamp.Results The bone nodules of MSCs osteogenic differentiation turned red after alizarin red staining,and lipid droplets of adipogenic differentiation turned red after oil red O staining;Under transmission electron microscope,MPs membrane had a complete structure,a clear outline and a diameter of about200 nm;The positive rates of CD29 and CD90 on the surface of MPs were(98. 24 ± 0. 82)% and(97. 69 ± 1. 83)%,respectively. Compared with Control group,the left ventricular end diastolic dimension(LVEDD)reduced signifi-cantly(t =5. 065,P < 0. 05),while the interventricular septum end-diastolic dimension(IVSd),left ventricular posterior wall dimension(LVPWd),heart weight to body weight ratio(HW/BW),and heart weight to tibial length ratio(HW/Tibia)significantly increased in ISO group(t = 4. 013,2. 368,4. 392,5. 043 and 6. 120,respectively,each P < 0. 05),indicating that the hypertrophic model was successfully established. The expression levels of ANP and BNP mRNA in hypertrophic cardiomyocytes of rats in ISO group were significantly higher than those in Control group(t = 25. 120 and18. 261,respectively,each P < 0. 01);While the expression levels of ANP and BNP mRNA in MPs group significantly reduced after incubation with 48 μg/mL MPs for 48 h compared with ISO group(t = 12. 110 and 3. 526,respectively,each P < 0. 05);The expression levels of CaMK Ⅱand p-CaMKⅡ in ISO group were significantly higher than those in Control group(t = 3. 278 and 4. 181,respectively,each P < 0. 05),while the expression of p-CaMK Ⅱ in MPs group decreased significantly(t = 5. 420,P < 0. 05);The calcium current density in ISO group was significantly higher than that in Control group(t = 15. 261,P < 0. 01),while that in MPs group was significantly lower than that in ISO group(t =6. 216,P < 0. 05).Conclusion MSC-MPs can significantly inhibit ISO-induced cardiomyocyte hypertrophy in rats,which is related to its down-regulation of cardiomyocyte CaMKⅡ and inhibition of L-type calcium channel.

Mechanism of salvianolic acid B protecting H9C2 from OGD/R injury based on mitochondrial fission and fusion / 药学学报

This study aims to investigate the effect of salvianolic acid B (Sal B), the active ingredient of Salvia miltiorrhiza, on H9C2 cardiomyocytes injured by oxygen and glucose deprivation/reperfusion (OGD/R) through regulating mitochondrial fission and fusion. The process of myocardial ischemia-reperfusion injury was simulated by establishing OGD/R model. The cell proliferation and cytotoxicity detection kit (cell counting kit-8, CCK-8) was used to detect cell viability; the kit method was used to detect intracellular reactive oxygen species (ROS), total glutathione (t-GSH), nitric oxide (NO) content, protein expression levels of mitochondrial fission and fusion, apoptosis-related detection by Western blot. Mitochondrial permeability transition pore (MPTP) detection kit and Hoechst 33342 fluorescence was used to observe the opening level of MPTP, and molecular docking technology was used to determine the molecular target of Sal B. The results showed that relative to control group, OGD/R injury reduced cell viability, increased the content of ROS, decreased the content of t-GSH and NO. Furthermore, OGD/R injury increased the protein expression levels of dynamin-related protein 1 (Drp1), mitofusions 2 (Mfn2), Bcl-2 associated X protein (Bax) and cysteinyl aspartate specific proteinase 3 (caspase 3), and decreased the protein expression levels of Mfn1, increased MPTP opening level. Compared with the OGD/R group, it was observed that Sal B had a protective effect at concentrations ranging from 6.25 to 100 μmol·L-1. Sal B decreased the content of ROS, increased the content of t-GSH and NO, and Western blot showed that Sal B decreased the protein expression levels of Drp1, Mfn2, Bax and caspase 3, increased the protein expression level of Mfn1, and decreased the opening level of MPTP. In summary, Sal B may inhibit the opening of MPTP, reduce cell apoptosis and reduce OGD/R damage in H9C2 cells by regulating the balance of oxidation and anti-oxidation, mitochondrial fission and fusion, thereby providing a scientific basis for the use of Sal B in the treatment of myocardial ischemia reperfusion injury.

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.

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.

Liraglutide inhibits high glucose-induced cardiomyocyte hypertrophy via modulating autophagy and Na / 中国药理学通报

Aim To investigate the mechanism through which liraglutide (LRG) inhibited high glucose (HG)-induced cardiomyocyte hypertrophy. Methods Cultured H9c2 were divided into control (CON) group, HG group, low-, middle- and high-dose LRG (LRG-L, LRG-M and LRG-H) groups, LRG-H + autophagy inhibitor trimethyladenine (3-MA) group. The relative cell surface change was assessed phalloidin staining. Membrane bound Na, K

Myocardial specific overexpression of Sirt1 inhibits recovery of cardiac function in mice with myocardial ischemia / 中国药理学通报

Aim To investigate the effect of overexpression of silent information regulator 1 (Sirtl) on cardiac function in mice with myocardial ischemia. Methods Myocardial specific Sirtl overexpression transgenic mice (Sirtl-Tg) and littermate control mice (C57BL/6J), half male and half female, were randomly divided into control sham operation group (Con), control model group (Con +ISO), Sirtl overexpression sham operation group (Sirtl-Tg) and Sirtl overexpression model group (Sirtl-Tg + ISO). Isoproterenol (ISO) was injected subcutaneously into the back of the neck at 100 mg • kg

Effect of boschniakia rossica polysaccharides on hypoxia/reoxygenation-induced cardiomyocyte damage by down-regulating miR-302a-3p expression / 中国药理学通报

Aim To explore the effect of boschniakia rossica polysaccharides ( BRPS ) on cardiomyocyte damage induced by hypoxia/reoxygenation (H/R) and its possible mechanism. Methods H/R was used to induce rat cardiomyocyte H9c2 to establish a cell inju¬ry model, and different doses of BRPS were used to treat H9c2 cells. ELISA method was used to detect the level of MDA and the activity of SOD and GSH-Px. Flow cytometry was used to detect the rate of apopto-sis. qRT-PCR was used to detect the expression of miR-302a-3p. anti-miR-NC and anti-miR-302a-3p were respectively transfected into H9c2 cells and then subjected to H/R treatment. miR-NC and miR-302a-3p mimics were respectively transfected into H9c2 cells and treated with 100 mg • L

TBC1D15 deficiency protects against doxorubicin cardiotoxicity via inhibiting DNA-PKcs cytosolic retention and DNA damage

Clinical application of doxorubicin (DOX) is heavily hindered by DOX cardiotoxicity. Several theories were postulated for DOX cardiotoxicity including DNA damage and DNA damage response (DDR), although the mechanism(s) involved remains to be elucidated. This study evaluated the potential role of TBC domain family member 15 (TBC1D15) in DOX cardiotoxicity. Tamoxifen-induced cardiac-specific Tbc1d15 knockout (Tbc1d15CKO) or Tbc1d15 knockin (Tbc1d15CKI) male mice were challenged with a single dose of DOX prior to cardiac assessment 1 week or 4 weeks following DOX challenge. Adenoviruses encoding TBC1D15 or containing shRNA targeting Tbc1d15 were used for Tbc1d15 overexpression or knockdown in isolated primary mouse cardiomyocytes. Our results revealed that DOX evoked upregulation of TBC1D15 with compromised myocardial function and overt mortality, the effects of which were ameliorated and accentuated by Tbc1d15 deletion and Tbc1d15 overexpression, respectively. DOX overtly evoked apoptotic cell death, the effect of which was alleviated and exacerbated by Tbc1d15 knockout and overexpression, respectively. Meanwhile, DOX provoked mitochondrial membrane potential collapse, oxidative stress and DNA damage, the effects of which were mitigated and exacerbated by Tbc1d15 knockdown and overexpression, respectively. Further scrutiny revealed that TBC1D15 fostered cytosolic accumulation of the cardinal DDR element DNA-dependent protein kinase catalytic subunit (DNA-PKcs). Liquid chromatography-tandem mass spectrometry and co-immunoprecipitation denoted an interaction between TBC1D15 and DNA-PKcs at the segment 594-624 of TBC1D15. Moreover, overexpression of TBC1D15 mutant (∆594-624, deletion of segment 594-624) failed to elicit accentuation of DOX-induced cytosolic retention of DNA-PKcs, DNA damage and cardiomyocyte apoptosis by TBC1D15 wild type. However, Tbc1d15 deletion ameliorated DOX-induced cardiomyocyte contractile anomalies, apoptosis, mitochondrial anomalies, DNA damage and cytosolic DNA-PKcs accumulation, which were canceled off by DNA-PKcs inhibition or ATM activation. Taken together, our findings denoted a pivotal role for TBC1D15 in DOX-induced DNA damage, mitochondrial injury, and apoptosis possibly through binding with DNA-PKcs and thus gate-keeping its cytosolic retention, a route to accentuation of cardiac contractile dysfunction in DOX-induced cardiotoxicity.

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.

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.

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.

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.

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.

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.

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.

Arctigenin regulates the effect of miR-21 on hypoxia-reoxygenation-induced pyroptosis of cardiomyocytes / 西安交通大学学报(医学版)

【Objective】 To investigate the effect and mechanism of arctigenin (ARG) on hypoxia-reoxygenation (H/R) induced pyroptosis of cardiomyocytes. 【Methods】 H9C2 cells were cultured in vitro, and underwent hypoxia for 2 hours and reoxygenation for 4 hours to establish H/R cell injury model. The cells were divided into control group (Control), model group (H/R), ARG group, miR-21 simulation group (miR-21 mimic), and ARG+miR-21 inhibitor group (ARG+miR-21 inhibitor). TUNEL staining was used to detect the pyroptosis index of H9C2 cells; the lactate dehydrogenase (LDH) kit was used to detect the release of LDH in each group of cells; the enzyme-linked immunosorbent assay (ELISA) was used to detect the content of interleukin-1β (IL-1β) and interleukin-18 (IL-18). Western blotting was used to detect the expressions of pyroptosis-related proteins (Caspase-1, GSDMD, IL-1β and IL-18) in each group. 【Results】 Compared with those in the control group, the pyroptosis index, the release of LDH, IL-1β and IL-18, and the protein expressions of Caspase-1p20, GSDMD-N, IL-1β and IL-18 in the H/R group were significantly increased (P<0.01). Compared with H/R group, ARG group and miR-21 mimic group had significantly reduced pyroptosis index, LDH, IL-1β and IL-18 release, and protein expressions of Caspase-1 p20, GSDMD-N, IL-1β and IL-18 (P<0.01), and the above-mentioned index changes could be reversed after treatment with +miR-21 inhibitor. 【Conclusion】 ARG can inhibit H/R-induced pyroptosis of cardiomyocytes, and its mechanism is related to the promotion of miR-21 expression.