RESUMEN
BACKGROUND: Glucose fluctuations may be involved in the pathophysiological process of cardiomyocyte apoptosis, but the exact mechanism remains elusive. This study focused on exploring the mechanisms related to glucose fluctuation-induced cardiomyocyte apoptosis. METHODS: Diabetic rats established via an injection of streptozotocin were randomized to five groups: the controlled diabetic (CD) group, the uncontrolled diabetic (UD) group, the glucose fluctuated diabetic (GFD) group, the GFD group rats with the injection of 0.9% sodium chloride (NaCl) (GFD + NaCl) and the GFD group rats with the injection of N-acetyl-L-cysteine (NAC) (GFD + NAC). Twelve weeks later, cardiac function and apoptosis related protein expressions were tested. Proteomic analysis was performed to further analyze the differential protein expression pattern of CD and GFD. RESULTS: The left ventricular ejection fraction levels and fractional shortening levels were decreased in the GFD group, compared with those in the CD and UD groups. Positive cells tested by DAB-TUNEL were increased in the GFD group, compared with those in the CD group. The expression of Bcl-2 was decreased, but the expressions of Bax, cleaved caspase-3 and cleaved caspase-9 were increased in response to glucose fluctuations. Compared with CD, there were 527 upregulated and 152 downregulated proteins in GFD group. Txnip was one of the differentially expressed proteins related to oxidative stress response. The Txnip expression was increased in the GFD group, while the Akt phosphorylation level was decreased. The interaction between Txnip and Akt was enhanced when blood glucose fluctuated. Moreover, the application of NAC partially reversed glucose fluctuations-induced cardiomyocyte apoptosis. CONCLUSIONS: Glucose fluctuations lead to cardiomyocyte apoptosis by up-regulating Txnip expression and enhancing Txnip-Akt interaction.
Asunto(s)
Proteínas Reguladoras de la Apoptosis , Apoptosis , Glucemia , Proteínas Portadoras , Diabetes Mellitus Experimental , Miocitos Cardíacos , Proteínas Proto-Oncogénicas c-akt , Ratas Sprague-Dawley , Transducción de Señal , Animales , Miocitos Cardíacos/patología , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/efectos de los fármacos , Apoptosis/efectos de los fármacos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Diabetes Mellitus Experimental/metabolismo , Masculino , Proteínas Portadoras/metabolismo , Glucemia/metabolismo , Proteínas Reguladoras de la Apoptosis/metabolismo , Fosforilación , Función Ventricular Izquierda/efectos de los fármacos , Tiorredoxinas/metabolismo , Cardiomiopatías Diabéticas/metabolismo , Cardiomiopatías Diabéticas/patología , Cardiomiopatías Diabéticas/fisiopatología , Cardiomiopatías Diabéticas/etiología , Proteómica , Ratas , Mapas de Interacción de Proteínas , Proteínas de Ciclo CelularRESUMEN
Enkephalins are reportedly correlated with heart function. However, their regulation in the heart remains unexplored. This study revealed a substantial increase in circulating levels of opioid growth factor (OGF) (also known as methionine enkephalin) and myocardial expression levels of both OGF and its receptor (OGFR) in subjects treated with doxorubicin (Dox). Silencing OGFR through gene knockout or using adeno-associated virus serotype 9 carrying small hairpin RNA effectively alleviated Dox-induced cardiotoxicity (DIC) in mice. Conversely, OGF supplementation exacerbated DIC manifestations, which could be abolished by administration of the OGFR antagonist naltrexone (NTX). Mechanistically, the previously characterized OGF/OGFR/P21 axis was identified to facilitate DIC-related cardiomyocyte apoptosis. Additionally, OGFR was observed to dissociate STAT1 from the promoters of ferritin genes (FTH and FTL), thereby repressing their transcription and exacerbating DIC-related cardiomyocyte ferroptosis. To circumvent the compromised therapeutic effects of Dox on tumors owing to OGFR blockade, SiO2-based modifiable lipid nanoparticles were developed for heart-targeted delivery of NTX. The pretreatment of tumor-bearing mice with the assembled NTX nanodrug successfully provided cardioprotection against Dox toxicity without affecting Dox therapy in tumors. Taken together, this study provides a novel understanding of Dox cardiotoxicity and sheds light on the development of cardioprotectants for patients with tumors receiving Dox treatment.
Asunto(s)
Cardiotoxicidad , Doxorrubicina , Miocitos Cardíacos , Animales , Doxorrubicina/efectos adversos , Ratones , Cardiotoxicidad/metabolismo , Cardiotoxicidad/prevención & control , Cardiotoxicidad/genética , Cardiotoxicidad/etiología , Cardiotoxicidad/patología , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/patología , Humanos , Apoptosis/efectos de los fármacos , Encefalina Metionina/metabolismo , Encefalina Metionina/farmacología , Receptores Opioides/metabolismo , Receptores Opioides/genética , Masculino , Transducción de Señal/efectos de los fármacos , Nanopartículas , Ratones Endogámicos C57BLRESUMEN
Fibronectin type III domain containing 4 (FNDC4) is highly homologous with FNDC5, which possesses various cardiometabolic protective functions. Emerging evidence suggests a noteworthy involvement of FNDC4 in fat metabolism and inflammatory processes. This study aimed to characterize the role of FNDC4 in myocardial ischemia/reperfusion (MI/R) injury and decrypt its underlying mechanisms. MI/R models of mice were established to investigate the alteration of FNDC4 in plasma and myocardium. We observed that plasma FNDC4 in MI/R-injury mice and patients experiencing acute myocardial infarction were both significantly reduced as opposed to their respective controls. Likewise, FNDC4 expression of myocardium decreased markedly in MI/R mice compared to the sham-operated group. Mice of FNDC4 knockout and myocardial overexpression were further introduced to elucidate the role of FNDC4 in MI/R injury by detecting cardiomyocyte apoptosis, myocardial infarct size, and cardiac function. Ablation of FNDC4 exacerbated cardiac dysfunction, increased myocardial infarction area and cardiomyocyte apoptosis when matched with wild-type mice post-MI/R. In contrast, FNDC4 overexpression through intramyocardial injection of rAAV9-Fndc4 significantly ameliorated cardiac function, reduced myocardial infarction area and cardiomyocyte apoptosis compared to sham group. Additionally, hypoxia-reoxygenation (H/R) was used to induce cardiomyocyte apoptosis, and to further elucidate the direct effects of FNDC4 on cardiomyocytes in vitro, and the results demonstrated that neonatal rat ventricular cardiomyocytes overexpressing FNDC4 showed less H/R-induced apoptosis, as evidenced by cleaved caspase 3 expression, TUNEL staining and flow cytometry. By performing RNA-seq analysis followed by cause-effect analysis, ERK1/2-Nrf2 pathway-mediated antioxidative effects were responsible for the protective roles of FNDC4 on cardiomyocytes. In summary, FNDC4 exerts cardioprotection against MI/R injury predominantly through mitigating oxidative stress responses and reducing cardiomyocyte apoptosis. These insights solidify the proposition of FNDC4 as a potential therapeutic aim for tackling MI/R damage.
RESUMEN
Heart failure (HF) is a clinical syndrome caused by the progression of various cardiac diseases to severe stages, and exercise training plays a positive role in the development of HF. This study aimed to investigate the impact of different intensities of exercise training on HF rats.In this study, we established two HF rat models by intraperitoneal injection of isoproterenol at 2.5 mg/kg/day and abdominal aortic coarctation. After exercise training for 4 weeks, the heart weight/body weight ratio and echocardiography results were measured. Moreover, the regulatory effect of different exercise intensities on myocardial function in HF model rats was verified using tissue staining, western blotting, and reagent kits.Exercise training had a bidirectional adjust effect on HF. A running training program of 20 minutes/time had the most significant effect on improving myocardial function in HF rats, whereas exercise intensity of 40 minutes/time or 50 minutes/time did not significantly improve myocardial function in HF rats. Moreover, exercise intensities of 20 minutes/time and 30 minutes/time could reduce the expression levels of the HF markers NT-proBNP and BNP in rats, but the effect was more significant at a duration of 20 minutes/time. We also found that compared with other exercise intensities, 20 minutes/time exercise intensity could significantly improve myocardial fibrosis, promote cardiomyocyte autophagy, and reduce apoptosis in combating HF.Furthermore, an exercise intensity of 20 minutes/time can significantly ameliorate the progression of HF. However, the degree of significance of increasing exercise intensity in improving HF progression is weakened or has no significant effect.
Asunto(s)
Modelos Animales de Enfermedad , Insuficiencia Cardíaca , Condicionamiento Físico Animal , Ratas Sprague-Dawley , Animales , Insuficiencia Cardíaca/fisiopatología , Insuficiencia Cardíaca/terapia , Insuficiencia Cardíaca/metabolismo , Ratas , Condicionamiento Físico Animal/fisiología , Masculino , Apoptosis , Péptido Natriurético Encefálico/metabolismo , Péptido Natriurético Encefálico/sangre , Ecocardiografía , Miocitos Cardíacos/metabolismo , Isoproterenol/farmacología , Miocardio/metabolismo , Miocardio/patología , Autofagia/fisiologíaRESUMEN
Heart failure with preserved ejection fraction (HFpEF) is a clinical syndrome characterized by pulmonary and systemic congestion resulting from left ventricular diastolic dysfunction and increased filling pressure. Currently, however, there is no evidence on effective pharmacotherapy for HFpEF. In this study, we aimed to investigate the therapeutic effect of total xanthones extracted from Gentianella acuta (TXG) on HFpEF by establishing an high-fat diet (HFD) + L-NAME-induced mouse model. Echocardiography was employed to assess the impact of TXG on the cardiac function in HFpEF mice. Haematoxylin and eosin staining, wheat germ agglutinin staining, and Masson's trichrome staining were utilized to observe the histopathological changes following TXG treatment. The results demonstrated that TXG alleviated HFpEF by reducing the expressions of genes associated with myocardial hypertrophy, fibrosis and apoptosis. Furthermore, TXG improved cardiomyocyte apoptosis by inhibiting the expression of apoptosis-related proteins. Mechanistic investigations revealed that TXG could activate the inositol-requiring enzyme 1α (IRE1α)/X-box-binding protein 1 (Xbp1s) signalling pathway, but the knockdown of IRE1α using the IRE1α inhibitor STF083010 or siRNA-IRE1α impaired the ability of TXG to ameliorate cardiac remodelling in HFpEF models. In conclusion, TXG alleviates myocardial hypertrophy, fibrosis and apoptosis through the activation of the IRE1α/Xbp1s signalling pathway, suggesting its potential beneficial effects on HFpEF patients.
Asunto(s)
Apoptosis , Endorribonucleasas , Insuficiencia Cardíaca , Proteínas Serina-Treonina Quinasas , Transducción de Señal , Proteína 1 de Unión a la X-Box , Xantonas , Animales , Endorribonucleasas/metabolismo , Endorribonucleasas/genética , Insuficiencia Cardíaca/tratamiento farmacológico , Insuficiencia Cardíaca/metabolismo , Proteína 1 de Unión a la X-Box/metabolismo , Proteína 1 de Unión a la X-Box/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Transducción de Señal/efectos de los fármacos , Ratones , Masculino , Xantonas/farmacología , Xantonas/aislamiento & purificación , Apoptosis/efectos de los fármacos , Modelos Animales de Enfermedad , Ratones Endogámicos C57BL , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Dieta Alta en Grasa/efectos adversos , Fibrosis , Volumen Sistólico/efectos de los fármacosRESUMEN
Brahma-related gene 1 (BRG1) has been implicated in the repair of DNA double-strand breaks (DSBs). Downregulation of BRG1 impairs DSBs repair leading to accumulation of double-stranded DNA (dsDNA). Currently, the role of BRG1 in diabetic cardiomyopathy (DCM) has not been clarified. In this study, we aimed to explore the function and molecular by which BRG1 regulates DCM using mice and cell models. We found that BRG1 was downregulated in the cardiac tissues of DCM mice and in cardiomyocytes cultured with high glucose and palmitic acid (HG/PA), which was accompanied by accumulation of dsDNA and activation of the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway. shRNA-mediated Brg1 knockdown aggravated DCM mice cardiac functions, enhanced dsDNA accumulation, cGAS-STING signaling activation, which induced inflammation and apoptosis. In addition, the results were further verified in HG/PA-treated primary neonatal rat cardiomyocytes (NRCMs). Overexpression of BRG1 in NRCMs yielded opposite results. Furthermore, a selective cGAS inhibitor RU.521 or STING inhibitor C-176 partially reversed the BRG1 knockdown-induced inflammation and apoptosis in vitro. In conclusion, our results demonstrate that BRG1 is downregulated during DCM in vivo and in vitro, resulting in cardiomyocyte inflammation and apoptosis due to dsDNA accumulation and cGAS-STING signaling activation. Therefore, targeting the BRG1-cGAS-STING pathway may represent a novel therapeutic strategy for improving cardiac function of patients with DCM.
RESUMEN
Anshen Shumai Decoction (ASSMD) is traditionally employed to manage coronary artery disease arrhythmias. Its protective efficacy against myocardial infarction remains to be elucidated. This investigation employed a rat model of myocardial infarction, achieved through the ligation of the left anterior descending (LAD) coronary artery, followed by a 28-day administration of ASSMD. The study observed the decoction's mitigative impact on myocardial injury, with gene regulation effects discerned through transcriptomic analysis. Furthermore, ASSMD's influence on cardiomyocyte apoptosis and fibrotic protein secretion was assessed using an embryonic rat cardiomyocyte cell line (H9c2) under hypoxic conditions and rat cardiac fibroblasts subjected to normoxic culture conditions with TGF-ß. A functional rescue assay involving overexpression of FOS and Early Growth Response Factor 1 (EGR1), combined with inhibition of the p38 Mitogen-activated Protein Kinase (MAPK) pathway, was conducted. Results indicated that ASSMD significantly curtailed cardiomyocyte apoptosis and myocardial fibrosis in infarcted rats, primarily by downregulating FOS and EGR1 gene expression and inhibiting the upstream p38 MAPK pathway. These actions of ASSMD culminated in reduced expression of pro-apoptotic, collagen, and fibrosis-associated proteins, conferring myocardial protection and anti-fibrotic effects on cardiac fibroblasts.
Asunto(s)
Proteína 1 de la Respuesta de Crecimiento Precoz , Infarto del Miocardio , Miocitos Cardíacos , Proteínas Proto-Oncogénicas c-fos , Proteínas Quinasas p38 Activadas por Mitógenos , Animales , Infarto del Miocardio/metabolismo , Infarto del Miocardio/tratamiento farmacológico , Infarto del Miocardio/patología , Proteína 1 de la Respuesta de Crecimiento Precoz/metabolismo , Proteína 1 de la Respuesta de Crecimiento Precoz/genética , Ratas , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Proteínas Proto-Oncogénicas c-fos/metabolismo , Proteínas Proto-Oncogénicas c-fos/genética , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/efectos de los fármacos , Masculino , Apoptosis/efectos de los fármacos , Remodelación Ventricular/efectos de los fármacos , Medicamentos Herbarios Chinos/farmacología , Medicamentos Herbarios Chinos/uso terapéutico , Inflamación/tratamiento farmacológico , Inflamación/metabolismo , Inflamación/patología , Ratas Sprague-Dawley , Fibrosis , Línea Celular , Transducción de Señal/efectos de los fármacos , Modelos Animales de Enfermedad , Sistema de Señalización de MAP Quinasas/efectos de los fármacosRESUMEN
The disruption of mitochondria homeostasis can impair the contractile function of cardiomyocytes, leading to cardiac dysfunction and an increased risk of heart failure. This study introduces a pioneering therapeutic strategy employing mitochondria derived from human umbilical cord mesenchymal stem cells (hu-MSC) (MSC-Mito) for heart failure treatment. Initially, we isolated MSC-Mito, confirming their functionality. Subsequently, we monitored the process of single mitochondria transplantation into recipient cells and observed a time-dependent uptake of mitochondria in vivo. Evidence of human-specific mitochondrial DNA (mtDNA) in murine cardiomyocytes was observed after MSC-Mito transplantation. Employing a doxorubicin (DOX)-induced heart failure model, we demonstrated that MSC-Mito transplantation could safeguard cardiac function and avert cardiomyocyte apoptosis, indicating metabolic compatibility between hu-MSC-derived mitochondria and recipient mitochondria. Finally, through RNA sequencing and validation experiments, we discovered that MSC-Mito transplantation potentially exerted cardioprotection by reinstating ATP production and curtailing AMPKα-mTOR-mediated excessive autophagy.
Asunto(s)
Proteínas Quinasas Activadas por AMP , Apoptosis , Autofagia , Células Madre Mesenquimatosas , Mitocondrias , Miocitos Cardíacos , Serina-Treonina Quinasas TOR , Animales , Humanos , Masculino , Ratones , Proteínas Quinasas Activadas por AMP/metabolismo , Doxorrubicina/farmacología , Insuficiencia Cardíaca/metabolismo , Células Madre Mesenquimatosas/metabolismo , Ratones Endogámicos C57BL , Mitocondrias/metabolismo , Mitocondrias/trasplante , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Serina-Treonina Quinasas TOR/metabolismoRESUMEN
Qixue Shuangbu prescription (QSP) has been used for the treatment of chronic heart failure (CHF) with remarkable curative effect. Processed QSP (PQSP) could significantly improve the treatment of CHF after traditional Chinese medicine (TCM) processing. This study elucidated the underlying efficacy enhancement mechanism of QSP after TCM processing for treating CHF in vitro and in vivo. The injury of rat cardiomyoblast H9c2 cells was induced by anoxia/reoxygenation to mimic CHF state in vitro. Sixty Sprague-Dawley rats were used to established CHF model by intraperitoneally injecting doxorubicin (the accumulative dose 15 mg/kg). Biochemical examinations were performed in serum and cellular supernatant, respectively. Cardiac functions and histopathological changes were evaluated in CHF model rats. The protein and mRNA levels of ERK1/2, Bcl-2, Bax and Caspase-3 were evaluated by Western blot and RT-PCR, respectively. All above results of low dose crude QSP-treated group (L-CQSP), high dose CQSP-treated group (H-CQSP), low dose PQSP-treated group (L-PQSP), high dose PQSP-treated group (H-PQSP) were compared to systematically explore correlations between TCM processing and the efficacy enhancement for treating CHF of PQSP. Compared with the model group, the L-CQSP group showed significant improvement in cardiac function at 8th weeks, while no significant improvement in cardiomyocyte apoptosis and fibrosis. Both H-CQSP, L-PQSP and H-PQSP exerted beneficial therapeutic effects in injured H9c2 cardiomyocytes and CHF model rats. L-PQSP and H-PQSP significantly increased cell viability and the activity of SOD, decreased the activities of LDH, MDA and NO, up-regulated the expression of ERK1/2 and Bcl-2, down-regulated the expression of Bax and Caspase-3 compared to the same dosage of CQSP. The efficacy enhancement mechanism of PQSP after TCM processing for treating CHF was directly related to the regulation of ERK/Bcl-2/Bax/Caspases-3 signaling pathway.
RESUMEN
Hypoxia-induced cardiomyocyte apoptosis is one major pathological change of acute myocardial infarction (AMI), but the underlying mechanism remains unexplored. CDC-like kinase 3 (CLK3) plays crucial roles in cell proliferation, migration and invasion, and nucleotide metabolism, however, the role of CLK3 in AMI, especially hypoxia-induced apoptosis, is largely unknown. The expression of CLK3 was elevated in mouse myocardial infarction (MI) models and neonatal rat ventricular myocytes (NRVMs) under hypoxia. Furthermore, CLK3 knockdown significantly promoted apoptosis and inhibited NRVM survival, while CLK3 overexpression promoted NRVM survival and inhibited apoptosis under hypoxic conditions. Mechanistically, CLK3 regulated the phosphorylation status of AKT, a key player in the regulation of apoptosis. Furthermore, overexpression of AKT rescued hypoxia-induced apoptosis in NRVMs caused by CLK3 deficiency. Taken together, CLK3 deficiency promotes hypoxia-induced cardiomyocyte apoptosis through AKT signaling pathway.
Asunto(s)
Apoptosis , Hipoxia de la Célula , Miocitos Cardíacos , Proteínas Serina-Treonina Quinasas , Proteínas Proto-Oncogénicas c-akt , Transducción de Señal , Animales , Masculino , Ratones , Ratas , Ratones Endogámicos C57BL , Infarto del Miocardio/patología , Infarto del Miocardio/metabolismo , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Fosforilación , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/deficiencia , Proteínas Tirosina Quinasas/metabolismo , Proteínas Tirosina Quinasas/genética , Proteínas Tirosina Quinasas/deficiencia , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas Sprague-DawleyRESUMEN
Reperfusion stands as a pivotal intervention for ischemic heart disease. However, the restoration of blood flow to ischemic tissue always lead to further damage, which is known as myocardial ischemia/reperfusion injury (MIRI). Ramelteon is an orally administered drug used to improve sleep quality, which is famous for its high bioadaptability and absence of notable addictive characteristics. However, the specific mechanism by which it improves MIRI is still unclear. Sirtuin-3 (Sirt3), primarily located in mitochondria, is crucial in mitigating many cardiac diseases, including MIRI. Based on the structure of Sirt3, we simulated molecular docking and identified several potential amino acid binding sites between it and ramelteon. Therefore, we propose a hypothesis that ramelteon may exert cardioprotective effects by activating the Sirt3 signaling pathway. Our results showed that the activation levels and expression level of Sirt3 were significantly decreased in MIRI tissue and H2O2 stimulated H9C2 cells, while ramelteon treatment upregulated Sirt3 activity and expression. After treat with 3-TYP, a classic Sirt3 activity inhibitor, we constructed myocardial ischemia/reperfusion surgery in vivo and induced H9C2 cells with H2O2 in vitro. The results showed that the myocardial protection and anti-apoptotic effects of ramelteon were antagonized by 3-TYP, indicating that the activation of Sirt3 is a key mechanism for ramelteon to exert myocardial protection. In summary, our results confirm a novel mechanism by which ramelteon improves MIRI by activating Sirt3 signaling pathway, providing strong evidence for the treatment of MIRI with ramelteon.
Asunto(s)
Indenos , Isquemia Miocárdica , Daño por Reperfusión Miocárdica , Sirtuina 3 , Humanos , Daño por Reperfusión Miocárdica/tratamiento farmacológico , Peróxido de Hidrógeno , Simulación del Acoplamiento Molecular , Miocitos Cardíacos , ApoptosisRESUMEN
BACKGROUND: The mitochondrial unfolded protein response (UPRmt) is the first line of defense against mitochondrial dysfunction in several diseases. Baicalein, which is an extract of Scutellaria baicalensis Georgi roots, exerts mitoprotective effects on metabolic disorders and cardiovascular diseases. However, it remains unclear whether baicalein alleviates obesity-induced cardiac damage through the UPRmt. PURPOSE: The present research designed to clarify the role of baicalein in lipotoxicity-induced myocardial apoptosis and investigated the UPRmt-related mechanism. METHODS: In the in vitro experiment, palmitic acid (PA)-treated AC16 cardiomyocytes were established to mimic obesity-induced myocardial injury. After pretreatment of AC16 cells with baicalein, the levels of cell vitality, apoptosis, mitochondrial membrane potential, mitochondrial oxidative stress, and UPRmt-related proteins were determined. Additionally, AC16 cells were treated with ML385 or siRNA to explore the regulation of the UPRmt by NRF2 signaling. In the in vivo experiment, male db/db mice administered with baicalein for 8 weeks were used to validate the effects of baicalein on cardiac damage induced by obesity, the UPRmt, and the NRF2-related pathway. RESULTS: In AC16 cardiomyocytes, PA dose-dependently increased the expression of UPRmt markers (HSP60, LONP1, ATF4, and ATF5). This increase was accompanied by enhanced production of mitochondrial ROS, reduced mitochondrial membrane potential, and elevated the expression levels of cytochrome c, cleaved caspase-3, and Bax/Bcl2, eventually leading to cell apoptosis. Baicalein treatment reversed UPRmt activation and mitochondrial damage and impeded mitochondrial-mediated cell apoptosis. Moreover, NRF2 downregulation by its inhibitor ML385 or siRNA diminished baicalein-mediated NRF2 signaling activation and UPRmt inhibition and triggered mitochondrial dysfunction. Additionally, NRF2 deficiency more intensely activated the UPRmt, resulting in mitochondrial oxidative stress and apoptosis of PA-induced cardiomyocytes, thus indicating that NRF2 plays a vital role in mitochondrial homeostasis regulation. In the in vivo study in db/db mice, baicalein inhibited the UPRmt, enhanced the antioxidant capacity, and attenuated cardiac dysfunction through a NRF2-activated pathway. CONCLUSION: To our best knowledge, these results provide the first insight that baicalein inhibits the UPRmt to induce a protective effect against lipotoxicity-induced mitochondrial damage and cardiomyocyte apoptosis via activating NRF2 signaling and suggest a new role of NRF2 in UPRmt regulation.
Asunto(s)
Flavanonas , Cardiopatías , Enfermedades Mitocondriales , Ratones , Animales , Masculino , Factor 2 Relacionado con NF-E2/metabolismo , Respuesta de Proteína Desplegada , Apoptosis , ARN Interferente Pequeño/farmacología , Enfermedades Mitocondriales/metabolismo , Estrés Oxidativo , Miocitos CardíacosRESUMEN
[Objective]To explore the mechanism of Qifu Qiangxin Decoction mitigating myocardial damage in heart failure(HF)mice with heart-kidney Yang deficiency syndrome.[Methods]Thirty C57BL/6 mice were randomly divided into Sham surgery group(Sham group),HF model(HF)group,low-dose Qifu Qiangxin Decoction(HF+QL)group,high-dose Qifu Qiangxin Decoction(HF+QH)group and western medicine[HF+angiotensin converting enzyme inhibitors(ACEI)]group,six in each group.In Sham group,the skin was cut open after anesthesia,the heart was exposed,the left anterior descending coronary artery was not in ligation,and then sutured.The rest were used to establish a mouse model of HF with heart-kidney Yang deficiency syndrome after myocardial infarction(MI)by ligating the left anterior descending coronary artery and swimming in cold water,then treated for 15 days.After treatment,the state of the mice was recorded,left ventricular end-diastolic volume(LVEDV),left ventricular end-systolic volume(LVESV),ejection fraction(EF)and left ventricular fractional shortening(LVFS)were measured by echocardiography to evaluate cardiac function;hematoxylin-eosin(HE)staining was used to evaluate the morphological of myocardial tissue;the serum levels of B-syndrome natriuretic peptide(BNP)were measured by enzyme linked immunosorbent assay(ELISA);terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling(TUNEL)was used to detect cardiomyocyte apoptosis;Western blot was used to determine the expression levels of apoptosis related proteins,autophagy related proteins and adenosine monophosphate-activated protein kinase/mammalian target of rapamycin(AMPK/mTOR)signaling pathway related proteins in mice myocardial tissue.[Results]Qifu Qiangxin Decoction can relieve the symptoms of HF in mice.Compared with Sham group,EF and LVFS values of mice in HF group were significantly decreased,while LVEDV and LVESV were significantly increased(P＜0.01).Compared with HF group,EF and LVFS values in each group were significantly increased,while LVEDV and LVESV were significantly decreased(P＜0.01),moreover,HF+QH group had a better effect than that of HF+QL group.According to HE staining,extensive necrotic myocardial tissue was observed in HF group compared with Sham group,and ELISA showed a significant increase in BNP levels(P＜0.01).Compared with HF group,the pathological conditions of myocardial tissue were relieve in each group,and the level of BNP was also significantly reduced(P＜0.01).TUNEL staining and Western blot results showed that the level of apoptosis in HF group was significantly increased compared with Sham group(P＜0.05).Compared with HF group,the apoptosis level of the each group was significantly reduced(P＜0.05).Therefore,Qifu Qiangxin Decoction could significantly reduce the level of cardiomyocyte apoptosis.Western blot detection of autophagy-related proteins and AMPK/mTOR signaling pathway related proteins showed that Qifu Qiangxin Decoction could significantly enhance autophagy level and regulate AMPK/mTOR signaling pathway in a concentration-dependent manner.[Conclusion]Qifu Qiangxin Decoction can regulate AMPK/mTOR signaling pathway,inhibit cell apoptosis and induce autophagy,thus protecting cardiomyocytes and mitigating myocardial injury.
RESUMEN
Obstructive sleep apnea (OSA) is characterized by intermittent hypoxia (IH) and is strongly associated with adverse cardiovascular outcomes. Myocardial injury and dysfunction have been commonly observed in clinical practice, particularly in patients with severe OSA. However, the underlying mechanisms remain obscure. In this review, we summarized the molecular mechanisms by which IH impact on myocardial injury and dysfunction. In brief, IH-induced cardiomyocyte death proceeds through the regulation of multiple biological processes, including differentially expressed transcription factors, alternative epigenetic programs, and altered post-translational modification. Besides cell death, various cardiomyocyte injuries, such as endoplasmic reticulum stress, occurs with IH. In addition to the direct effects on cardiomyocytes, IH has been found to deteriorate myocardial blood and energy supply by affecting the microvascular structure and disrupting glucose and lipid metabolism. For better diagnosis and treatment of OSA, further studies on the molecular mechanisms of IH-induced myocardial injury and dysfunction are essential.
Asunto(s)
Sistema Cardiovascular , Apnea Obstructiva del Sueño , Humanos , Hipoxia , Miocitos Cardíacos/metabolismoRESUMEN
Coronary atherosclerosis-induced myocardial ischemia leads to cardiomyocyte apoptosis. The regulatory mechanisms for cardiomyocyte apoptosis have not been fully understood. Circular RNAs are non-coding RNAs which play important roles in heart function maintenance and progression of heart diseases by regulating gene transcription and protein translation. Here, we reported a conserved cardiac circular RNA, which is generated from the second exon of LRP6 and named circLRP62-2 . CircLRP62-2 can protect cardiomyocyte from hypoxia-induced apoptosis. The expression of circLRP62-2 in cardiomyocytes was down-regulated under hypoxia, while forced expression of circLRP62-2 inhibited cell apoptosis. Normally, circLRP62-2 was mainly localized in the nucleus. Under hypoxia, circLRP62-2 is associated with heterogeneous nuclear ribonucleoprotein M (hnRNPM) to be translocated into the cytoplasm. It recruited hnRNPM to fibroblast growth factor 9 (FGF9) mRNA to enhance the expression of FGF9 protein, promoting hypoxia-adaption and viability of cardiomyocytes. In summary, this study uncovers a new inhibitor of apoptosis and reveals a novel anti-apoptotic pathway composed of circLRP62-2 , hnRNPM, and FGF9, which may provide therapeutic targets for coronary heart disease and ischemic myocardial injury.
Asunto(s)
MicroARNs , Miocitos Cardíacos , Humanos , Miocitos Cardíacos/metabolismo , ARN Circular/metabolismo , Ribonucleoproteína Heterogénea-Nuclear Grupo M/metabolismo , Factor 9 de Crecimiento de Fibroblastos/metabolismo , Apoptosis/genética , Hipoxia/metabolismo , MicroARNs/genéticaRESUMEN
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.
RESUMEN
BACKGROUND: Heart failure (HF) is a global health problem characterized by impaired heart function. Cardiac remodeling and cell death contribute to the development of HF. Although treatments such as digoxin and angiotensin receptor blocker drugs have been used, their effectiveness in reducing mortality is uncertain. Researchers are exploring the use of adipose-derived mesenchymal stem cell (ADMSC) exosomes (Exos) as a potential therapy for HF. These vesicles, secreted by cells, may aid in tissue repair and regulation of inflammation and immune responses. However, further investigation is needed to understand the specific role of these vesicles in HF treatment. AIM: To investigate the mechanism of extracellular vesicles produced by ADMSC s in the treatment of HF. METHODS: Exogenous surface markers of ADMSCs were found, and ADMSCs were cultured. RESULTS: The identification of surface markers showed that the surface markers CD44 and CD29 of adipose-derived stem cells (ADSCs) were well expressed, while the surface markers CD45 and CD34 of ADSCs were negative, so the cultured cells were considered ADSCs. Western blotting detected the Exo surface marker protein, which expressed CD63 protein but did not express calnexin protein, indicating that ADSC-derived Exos were successfully extracted. CONCLUSION: The secretion of MSCs from adipose tissue can increase ATP levels, block cardiomyocyte apoptosis, and enhance the heart function of animals susceptible to HF. The inhibition of Bax, caspase-3 and p53 protein expression may be related to this process.
RESUMEN
Doxorubicin (DOX) has aroused contradiction between its potent anti-tumor capacity and severe cardiotoxicity. Galangin (Gal) possesses antioxidant, anti-inflammatory, and antiapoptotic activities. We aimed to explore the role and underlying mechanisms of Gal on DOX-induced cardiotoxicity. Mice were intraperitoneally injected with DOX (3 mg/kg, every 2 days for 2 weeks) to generate cardiotoxicity model and Gal (15 mg/kg, 2 weeks) was co-administered via gavage daily. Nuclear factor erythroid 2-related factor 2 (Nrf2) specific inhibitor, ML385, was employed to explore the underlying mechanisms. Compared to DOX-insulted mice, Gal effectively improved cardiac dysfunction and ameliorated myocardial damage. DOX-induced increase of reactive oxygen species, malondialdehyde, and NADPH oxidase activity and downregulation of superoxide dismutase (SOD) activity were blunted by Gal. Gal also markedly blocked increase of IL-1ß, IL-6, and TNF-α in DOX-insulted heart. Mechanistically, Gal reversed DOX-induced downregulation of Nrf2, HO-1, and promoted nuclear translocation of Nrf2. ML385 markedly blunted the cardioprotective effects of Gal, as well as inhibitive effects on oxidative stress and inflammation. Gal ameliorates DOX-induced cardiotoxicity by suppressing oxidative stress and inflammation via activating Nrf2/HO-1 signaling pathway. Gal may serve as a promising cardioprotective agent for DOX-induced cardiotoxicity.
Asunto(s)
Cardiotoxicidad , Hemo-Oxigenasa 1 , Ratones , Animales , Cardiotoxicidad/tratamiento farmacológico , Hemo-Oxigenasa 1/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Apoptosis , Estrés Oxidativo , Doxorrubicina/efectos adversos , Transducción de Señal , Inflamación/metabolismo , Miocitos CardíacosRESUMEN
Introduction: The prevalence of ischemic heart disease has reached pandemic levels worldwide. Early revascularization is currently the most effective therapy for ischemic heart diseases but paradoxically induces myocardial ischemia/reperfusion (MI/R) injury. Cardiac inflammatory reaction and oxidative stress are primarily involved in the pathology of MI/R injury. Low-intensity pulsed ultrasound (LIPUS) has been demonstrated to reduce cell injury by protecting against inflammatory reaction and oxidative stress in many diseases, including cardiovascular diseases, but rarely on MI/R injury. Methods: This study was designed to clarify whether LIPUS alleviates MI/R injury by alleviating inflammatory reaction and oxidative stress. Simultaneously, we have also tried to confirm which intensity of the LIPUS might be more suitable to ameliorate the MI/R injury, as well as to clarify the signaling mechanisms. MI/R and simulated ischemia/reperfusion (SI/R) were respectively induced in Sprague Dawley rats and human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs). LIPUS treatment, biochemical measurements, cell death assay, estimation of cardiac oxidative stress and inflammatory reaction, and protein detections by western blotting were performed according to the protocol. Results: In our study, both in vivo and in vitro, LIPUS of 0.1 W/cm2 (LIPUS0.1) and 0.5 W/cm2 (LIPUS0.5) make no significant difference in the cardiomyocytes under normoxic condition. Under the hypoxic condition, MI/R injury, inflammatory reaction, and oxidative stress were partially ameliorated by LIPUS0.5 but were significantly aggravated by LIPUS of 2.5 W/cm2 (LIPUS2.5) both in vivo and in vitro. The activation of the apoptosis signal-regulating kinase 1 (ASK1)/c-Jun N-terminal kinase (JNK) pathway in cardiomyocytes with MI/R injury was partly rectified LIPUS0.5 both in vivo and in vitro. Conclusion: Our study firstly demonstrated that LIPUS of different intensities differently affects MI/R injury by regulating cardiac inflammatory reaction and oxidative stress. Modulations on the ASK1/JNK pathway are the signaling mechanism by which LIPUS0.5 exerts cardioprotective effects. LIPUS0.5 is promising for clinical translation in protecting against MI/R injury. This will be great welfare for patients suffering from MI/R injury.
Asunto(s)
Isquemia Miocárdica , Daño por Reperfusión Miocárdica , Ratas , Animales , Humanos , Ratas Sprague-Dawley , Daño por Reperfusión Miocárdica/terapia , Miocitos Cardíacos , Estrés Oxidativo , InflamaciónRESUMEN
AIMS: Molecular hydrogen has been exhibited a protective function in heart diseases. Our previous study demonstrated that hydrogen-rich saline (HRS) could scavenge free radicals selectively and alleviate the inflammatory response in the myocardial ischaemia/reperfusion (I/R) injury, but the underlying mechanism has not been fully clarified. METHODS AND RESULTS: Adult (10 weeks) C57BL/6 male mice and neonatal rat cardiomyocytes were used to establish I/R and hypoxia/reoxygenation (H/R) injury models. I/R and H/R models were treated with HRS to classify the mechanisms of cardioproctective function. In this study, we found that miR-124-3p was significantly decreased in both I/R and H/R models, while it was partially ameliorated by HRS pretreatment. HRS treatment also alleviated ischaemia-induced apoptotic cell death and increased cell viability during I/R process, whereas silencing expression of miR-124-3p abolished this protective effect. In addition, we identified calpain1 as a direct target of miR-124-3p, and up-regulation of miR-124-3 produced both activity and expression of calpain1. It was also found that compared with the HRS group, overexpression of calpain1 increased caspase-3 activities, promoted cleaved-caspase3 and Bax protein expressions, and correspondingly decreased Bcl-2, further reducing cell viability. These results illustrated that calpain1 overexpression attenuated protective effect of HRS on cardiomyocytes in H/R model. CONCLUSIONS: The present study showed a protective effect of HRS on I/R injury, which may be associated with miR-124-3p-calpain1 signalling pathway.