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Sepsis triggers myocardial injury and dysfunction, leading to a high mortality rate in patients. Cardiomyocyte apoptosis plays a positive regulatory role in septic myocardial injury and dysfunction. However, the mechanism is unclear.

Abstract 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.

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-β. 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. [ABSTRACT FROM AUTHOR]

Background: Myocardial ischemia-reperfusion injury (I/R) has been improved with drugs and effective reperfusion, but it still cannot be prevented. Methods: To investigate whether renal denervation (RDN) reduces cardiomyocyte apoptosis by ameliorating endoplasmic reticulum stress, 60 male specific pathogen-free (SPF) Wistar rats were randomly divided into 6 groups (n = 6). We established the I/R rat model by ligating the left anterior descending artery. The I/R+ angiotensin receptor neprilysin inhibitors (ARNI) group received ARNIs for 2 weeks until euthanasia. Results: The I/R+RDN and I/R+ARNI groups have signifiantly ameliorated left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) and reversed expansion of the left ventricular end-systolic diameter (LVSD) and left ventricular end diastolic diameter (LVDD) compared to the I/R group. The levels of norepinephrine (NE), angiotensin II, and aldosterone (ALD) increased signifiantly in the I/R group, but decreased signifiantly after RDN and ARNI intervention. In the I/R+RDN and I/R+ARNI groups, the myocardial tissue edema was alleviated. The infarct size was smaller in the I/R+RDN and I/R+ARNI groups compared to the I/R group. Apoptosis of cardiomyocytes and fib oblasts in myocardial tissue increased signifiantly in the I/R group, which was greatly diminished by RDN and ARNI. The expression of Bax, caspase-3, CHOP, PERK, and ATF4 protein was signifiantly increased in the I/R group, which compared to other groups, and the level of CHOP, PERK, and ATF4 gene expression increased. After RDN intervention, these expression levels recovered to varying degrees. Conclusion: The effect of RDN may be associated with regulating the endoplasmic reticulum stress PERK/ATF4 signaling pathway. [ABSTRACT FROM AUTHOR]

Background and aimAngelica sinensis (Oliv.) Diels (Danggui, DG), exhibits potential in myocardial infarction (MI) treatment. However, research on its synergistic combinations for cardioprotective effects has been limited owing to inadequate approaches.Experimental procedureWe identified certain phenolic acids and phthalein compounds in DG. Network pharmacology analysis and experimental validation revealed the components that protected H9c2 cells and reduced lactate dehydrogenase levels. Subsequently, a combination of computational experimental strategies and a secondary phenotypic optimization platform was employed to identify effective component combinations with synergistic interactions. The Chou-Talalay and Zero Interaction Potency (ZIP) models were utilized to quantify the synergistic relationships. The optimal combination identified, Z-Ligustide and Chlorogenic acid (Z-LIG/CGA), was evaluated for its protective effects on cardiac function and cardiomyocytes apoptosis induced by inflammatory in a mouse model of induced by left anterior descending coronary artery ligation. Flow cytometry was further utilized to detect the polarization ratio of M1/M2 macrophages and the expression of inflammatory cytokines in serum was measured, assessing the inhibition of inflammatory responses and pro-inflammatory signaling factors by Z-LIG/CGA.Key resultsQuadratic surface analysis revealed that the Z-LIG/CGA combination displayed synergistic cardioprotective effects (combination index value 10). In vivo, Z-LIG/CGA significantly improved cardiac function and reduced the fibrotic area in mice post-MI, surpassing the results in groups treated with Z-LIG or CGA alone. Compared to the MI group, the Z-LIG/CGA group exhibited decreased ratios of the myocardial cell apoptosis-related proteins BAX/Bcl-2 and Cleaved Caspase-3/Caspase-3 in mice. Further research revealed that Z-LIG/CGA treatment significantly increased IL-1R2 levels, significantly decreased IL-17RA levels, and inhibited the activation of p-STAT1, thereby alleviating cell apoptosis after MI. Additionally, the Z-LIG/CGA combination significantly inhibited the ratio of M1/M2 macrophages and suppressed the expression levels of pro-inflammatory cytokines IL-1β, IL-6, IL-17, and TNF-α in the serum.Conclusion and implicationsWe successfully identified a synergistic drug combination, Z-LIG/CGA, which improves MI outcomes by inhibiting cardiomyocyte apoptosis and inflammatory damage through modulating macrophage polarization and regulating the IL-1R2/IL-17RA/STAT1 signaling pathway. This study provides a charming paradigm to explore effective drug combinations in traditional Chinese medicine and a promising treatment for MI.

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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.

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.

Abstract 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.

Abstract Broiler ascites syndrome (AS) is one of the main diseases threatening the health of broilers. It is well documented that myocardial hypertrophy and failure is one of the key mechanisms of broiler ascites syndrome. Therefore, prevention of cardiac hypertrophy and failure would be one goal to reduce broiler ascites syndrome incidence. Myocardial hypertrophy and failure are closely related to endoplasmic reticulum stress (ERS) in cardiac myocytes, and the endoplasmic reticulum stress signaling system (ATF6-DR5) is one of the important pathways of myocardial apoptosis. Excessive hypertrophy will affect the heart muscle’s normal contraction and diastole function, and the heart will turn from compensated to decompensate thus causing myocardial injury. Myocardial apoptosis is a core component of the pathological changes of this myocardial injury. Nano-selenium is a kind of red elemental selenium nanoparticle. Due to its excellent physical, chemical and biological properties, it has attracted extensive academic attention in recent years. It has been proven to have excellent antioxidant, antibacterial, antitumor, antihypertrophic, and antiapoptotic abilities. Herein, nano-selenium (1 µmol/L) can inhibit hydrogen peroxide (H2O2)-induced oxidative stress in broiler primary cardiomyocytes, and at the same time reduce cardiomyocyte apoptosis. In vivo, nano-selenium can reduce broiler myocardial injury-related enzyme indicators (AST, CK and LDH), and alleviate myocardial injury. It can also activate the antioxidant enzyme system (SOD, GSH-Px and CAT) and reduce MDA, and make the recovery of T-AOC ability in the organization. Meanwhile, nano-selenium can down-regulate the genes and proteins expression of ATF-6, GRP-78, CHOP and caspase 12 in the ERS-related signaling pathway, and inhibit that of downstream-related caspase 3, Bax and caspase 9, and increase that of the downstream anti-apoptotic Bcl-2, thereby maintaining the homeostasis of the endoplasmic reticulum and alleviating cardiomyocyte apoptosis. It can be seen that nano-selenium can protect the damaged myocardium in the broiler ascites caused by high-salt drinking by regulating the ATF6-DR5 signaling pathway. This study was performed in chickens and cardiomyocyte cells and attempted to demonstrate that selenium nanoparticles can protect the damaged myocardium in broiler ascites. This paper provides a new idea for preventing and treating broiler ascites syndrome.

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 (Tbc1d15 CKO) or Tbc1d15 knockin (Tbc1d15 CKI) 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. TBC1D15 directly binds and interacts with DNA-PKcs, leading to cytosolic DNA-PKcs accumulation with compromised DNA-PKcs nuclear translocation, exacerbated DNA damage, resulting in mitochondrial anomalies and doxorubicin-induced cardiomyocyte apoptosis. [Display omitted] [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Epidemiological studies have shown an increased risk of cardiovascular diseases in children born to mothers who smoked during pregnancy. The cardiovascular risk in the offspring associated with in utero nicotine exposure is further exaggerated by maternal obesity. The consumption of electronic cigarettes (e-cigarettes) is alarmingly increasing among adolescents and young adults without the knowledge of their harmful health effects. There has also been a substantial increase in e-cigarette use by women of reproductive age. This study investigates the detrimental effects of gestational exposure of e-cigarette and a high-fat diet (HFD) on neonatal hearts. Time-mated pregnant mice were fed a HFD and exposed to saline or e-cigarette aerosol with 2.4% nicotine from embryonic day 4 (E4) to E20. We demonstrated that in utero exposure of e-cigarettes and HFD from E4 to E20 triggers cardiomyocyte (CM) apoptosis in the offspring at postnatal day1 (PND1), PND3, and PND14. Induction of CM apoptosis following gestational exposure of e-cigarettes and HFD was associated with inactivation of AMP-activated protein kinase (AMPK), increased cardiac oxidative stress coupled with perturbation of cardiac BAX/BCL-2 ratio and activation of caspase 3 at PND 14. Electron microscopy further revealed that left ventricles of pups at PND14 after e-cigarette exposure exhibited apoptotic nuclei, convoluted nuclear membranes, myofibrillar derangement, and enlarged mitochondria occasionally showing signs of crystolysis, indicative of cardiomyopathy and cardiac dysfunction. Our results show profound adverse effects of prenatal exposure of e-cigarette plus HFD in neonatal hearts that may lead to long-term adverse cardiac consequences in the adult.

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. [ABSTRACT FROM AUTHOR]

To explore the underlying mechanism of lncRNA MALAT1 in the pathogenesis of diabetic cardiomyopathy (DCM). DCM models were confirmed in db/db mice. MiRNAs in myocardium were detected by miRNA sequencing. The interactions of miR‐185‐5p with MALAT1 and RhoA were validated by dual‐luciferase reporter assays. Primary neonatal cardiomyocytes were cultured with 5.5 or 30 mmol/L D‐glucose (HG) in the presence or absence of MALAT1‐shRNA and fasudil, a ROCK inhibitor. MALAT1 and miR‐185‐5p expression were determined by real‐time quantitative PCR. The apoptotic cardiomyocytes were evaluated using flow cytometry and TUNEL staining. SOD activity and MDA contents were measured. The ROCK activity, phosphorylation of Drp1S616, mitofusin 2 and apoptosis‐related proteins were analysed by Western blotting. Mitochondrial membrane potential was examined by JC‐1. MALAT1 was significantly up‐regulated while miR‐185‐5p was down‐regulated in myocardium of db/db mice and HG‐induced cardiomyocytes. MALAT1 regulated RhoA/ROCK pathway via sponging miR‐185‐5p in cardiomyocytes in HG. Knockdown of MALAT1 and fasudil all inhibited HG‐induced oxidative stress, and alleviated imbalance of mitochondrial dynamics and mitochondrial dysfunction, accompanied by reduced cardiomyocyte apoptosis. MALAT1 activated the RhoA/ROCK pathway via sponging miR‐185‐5p and mediated HG‐induced oxidative stress, mitochondrial damage and apoptosis of cardiomyocytes in mice. [ABSTRACT FROM AUTHOR]

Broiler ascites syndrome (AS) is one of the main diseases threatening the health of broilers. It is well documented that myocardial hypertrophy and failure is one of the key mechanisms of broiler ascites syndrome. Therefore, prevention of cardiac hypertrophy and failure would be one goal to reduce broiler ascites syndrome incidence. Myocardial hypertrophy and failure are closely related to endoplasmic reticulum stress (ERS) in cardiac myocytes, and the endoplasmic reticulum stress signaling system (ATF6-DR5) is one of the important pathways of myocardial apoptosis. Excessive hypertrophy will affect the heart muscle's normal contraction and diastole function, and the heart will turn from compensated to decompensate thus causing myocardial injury. Myocardial apoptosis is a core component of the pathological changes of this myocardial injury. Nano-selenium is a kind of red elemental selenium nanoparticle. Due to its excellent physical, chemical and biological properties, it has attracted extensive academic attention in recent years. It has been proven to have excellent antioxidant, antibacterial, antitumor, antihypertrophic, and antiapoptotic abilities. Herein, nano-selenium (1 µmol/L) can inhibit hydrogen peroxide (H2O2)-induced oxidative stress in broiler primary cardiomyocytes, and at the same time reduce cardiomyocyte apoptosis. In vivo, nano-selenium can reduce broiler myocardial injury-related enzyme indicators (AST, CK and LDH), and alleviate myocardial injury. It can also activate the antioxidant enzyme system (SOD, GSH-Px and CAT) and reduce MDA, and make the recovery of T-AOC ability in the organization. Meanwhile, nano-selenium can down-regulate the genes and proteins expression of ATF-6, GRP-78, CHOP and caspase 12 in the ERS-related signaling pathway, and inhibit that of downstream-related caspase 3, Bax and caspase 9, and increase that of the downstream anti-apoptotic Bcl-2, thereby maintaining the homeostasis of the endoplasmic reticulum and alleviating cardiomyocyte apoptosis. It can be seen that nano-selenium can protect the damaged myocardium in the broiler ascites caused by high-salt drinking by regulating the ATF6-DR5 signaling pathway. This study was performed in chickens and cardiomyocyte cells and attempted to demonstrate that selenium nanoparticles can protect the damaged myocardium in broiler ascites. This paper provides a new idea for preventing and treating broiler ascites syndrome. [ABSTRACT FROM AUTHOR]

Background and objectives: Ischemic heart failure (HF) has become a disease that seriously endangers people's life and health. As a herbal formula widely used in clinical practice, new optimized Sheng-Mai-San (NO-SMS) has been shown to be significantly effective in improving cardiac function, increasing exercise tolerance, and slowing the progression of myocardial fibrosis in heart failure patients in multi-center clinical studies in various regions of China. In our previous pharmacodynamic and toxicological studies, we found that a medium-dose formulation (8.1 g of raw drug/kg) was the most effective in the treatment of heart failure, but its mechanism of action is still being investigated. The present study is exploring its relationship with cardiomyocyte apoptosis. Materials and methods: We investigated and verified this through two parts of experiments, in vivo and in vitro. Firstly, we prepared male SD rats with heart failure models by ligating the left anterior descending branch of the coronary artery (EF ≤ 50%), which were treated with NO-SMS Formula (8.1 g of raw drug/kg/d), Ifenprodil (5.4 mg/kg/d) or Enalapril (0.9 mg/kg/d) prepared suspensions by gavage for 4 weeks. The cardiac and structural changes were evaluated by echocardiography, H&E, and MASSON staining. The apoptosis of cardiomyocytes in each group was detected by Western blot, qRT-PCR, and ELISA. In vitro cell experiments include H9c2 cardiomyocyte injury induced by H2O2 and NMDA respectively, and the groups were incubated with NO-SMS and Ifenprodil-containing serum for 24 h. Apoptosis was detected by Annexin V-FITC/PI double-staining method, and the rest of the assays were consistent with the in vivo experiments. Results: Compared with the model group, the NO-SMS formula group and the Ifenprodil group could significantly improve cardiac function, delay myocardial fibrosis, reduce the expression of pro-apoptotic proteins, mRNA, and the concentration levels of Ca2+ and ROS in heart failure rats and H9c2 cardiomyocytes with H2O2 and NMDA-induced injury, which could significantly reduce the apoptosis rate of damaged cardiomyocytes and effectively inhibit the apoptosis of cardiomyocytes. Conclusion: NO-SMS Formula improved cardiac function, inhibited ventricular remodeling and cardiomyocyte apoptosis in HF rats, and its mechanism may be related to the regulation of the NMDAR signaling pathway, inhibition of large intracellular Ca2+ inward flow, and ROS production in cardiomyocytes.

Background Myocardial infarction (MI) is a cardiovascular disease with high morbidity and mortality. PI16 (peptidase inhibitor 16), as a secreted protein, is highly expressed in heart diseases such as heart failure. However, the functional role of PI16 in MI is unknown. This study aimed to investigate the role of PI16 after MI and its underlying mechanisms. Methods and Results PI16 levels after MI were measured by enzyme‐linked immunosorbent assay and immunofluorescence staining, which showed that PI16 was upregulated in the plasma of patients with acute MI and in the infarct zone of murine hearts. PI16 gain‐ and loss‐of‐function experiments were used to investigate the potential role of PI16 after MI. In vitro, PI16 overexpression inhibited oxygen–glucose deprivation–induced apoptosis in neonatal rat cardiomyocytes, whereas knockdown of PI16 exacerbated neonatal rat cardiomyocyte apoptosis. In vivo, left anterior descending coronary artery ligation was performed on PI16 transgenic mice, PI16 knockout mice, and their littermates. PI16 transgenic mice showed decreased cardiomyocyte apoptosis at 24 hours after MI and improved left ventricular remodeling at 28 days after MI. Conversely, PI16 knockout mice showed aggravated infract size and remodeling. Mechanistically, PI16 downregulated Wnt3a (wingless‐type MMTV integration site family, member 3a)/β‐catenin pathways, and the antiapoptotic role of PI16 was reversed by recombinant Wnt3a in oxygen–glucose deprivation–induced neonatal rat cardiomyocytes. PI16 also inhibited HDAC1 (class I histone deacetylase) expression, and overexpression HDAC1 abolished the inhibition of apoptosis and Wnt signaling of PI16. Conclusions In summary, PI16 protects against cardiomyocyte apoptosis and left ventricular remodeling after MI through the HDAC1‐Wnt3a‐β‐catenin axis.

Cardiomyocyte apoptosis has been characterized as one of the major mechanisms underlying doxorubicin (DOX)-induced cardiomyopathy. MicroRNA-21-5p (miR-21-5p) was reported to mitigate ischemia-induced cardiomyocyte apoptosis and cardiac injury. However, to our knowledge, the functional role of miR-21-5p in DOX-induced cardiomyopathy is unclear. In this study, we explored the role of miR-21-5p in DOX-induced cardiac injury. The expression level of miR-21-5p was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Dual luciferase reporter assay was used to verify the potential target gene of miR-21-5p. The apoptosis rate of NRCMs was detected by TUNEL staining assay. Western blot analysis was used to detect the protein expression levels of Bax, Bcl-2, Caspase3, cleaved-Caspase3 and BTG2. For animal studies, mice were injected with AAV9-miR-21-5p or AAV9-Empty viruses, and treated with DOX at a dose of 5 mg/kg per week through intraperitoneally administration. After 4 weeks of DOX treatment, mice were subjected to echocardiography to measure the left ventricular ejection fraction (EF) and fractional shortening (FS). Results showed that miR-21-5p was upregulated in both DOX-treated primary cardiomyocytes and mouse heart tissues. Interestingly, enhanced miR-21-5p expression inhibited DOX-induced cardiomyocyte apoptosis and oxidative stress, while decreased miR-21-5p expression promoted cardiomyocyte apoptosis and oxidative stress. Furthermore, cardiac overexpression of miR-21-5p protected against DOX-induced cardiac injury. The mechanistic study indicated that BTG2 was a target gene of miR-21-5p. The anti-apoptotic effect of miR-21-5p could be inhibited by BTG2 overexpression. Conversely, inhibition of BTG2 rescued the pro-apoptotic effect of miR-21-5p inhibitor. Taken together, our study showed that miR-21-5p could prevent DOX-induced cardiomyopathy by downregulating BTG2.

Sepsis remains a worldwide public health problem. This study aims to explore the role and mechanism of transcriptional factors (TFs) in sepsis‐induced myocardial injury. Firstly, TF KLF13 was selected to explore its role in sepsis‐induced myocardial injury. The caecal ligation and puncture (CLP) ‐induced sepsis mouse model was established and the septic mice were examined using standard histopathological methods. KLF13 expression was detected in the septic mouse heart and was also seen in a lipoploysaccharide (LPS) ‐induced cellular inflammation model. To explore this further both pro‐apoptotic cleaved‐caspase3/caspase3 and Bax levels and anti‐apoptotic Bcl2 levels were examined, also in both models, In addition inflammatory cytokine (IL‐1β, TNF‐α, IL‐8 and MCP‐1) production and IκB‐α protein level and p65 phosphorylation were examined in both septic mice and LPS‐induced cells. Thus three parameters ‐ cardiomyocyte apoptosis, inflammatory response and NF‐κB pathway activation were evaluated under similar conditions. The septic mice showed significant oedema, disordered myofilament arrangement and degradation and necrosis to varying degrees in the myocardial cells. KLF13 was downregulated in both the septic mouse heart and the LPS‐induced cellular inflammation model. Furthermore, both models showed abnormally increased cardiomyocyte apoptosis (increased cleaved‐caspase3/caspase and Bax protein levels and decreased Bcl2 level), elevated inflammation (increased production of inflammatory cytokines) and the activated NF‐κB pathway (increased p65 phosphorylation and decreased IκB‐α protein level). KLF13 overexpression notably ameliorated sepsis‐induced myocardial injury in vivo and in vitro. KLF13 overexpression protected against sepsis‐induced myocardial injury and LPS‐induced cellular inflammation and apoptosis via inhibiting the inflammatory pathways (especially NF‐κB signalling) and cardiomyocyte apoptosis. [ABSTRACT FROM AUTHOR]

Zhong-guo Fan,1 Yang Xu,1 Xi Chen,1 Ming-yue Ji,1,2 Gen-shan Ma1 1Department of Cardiology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, People’s Republic of China; 2Department of Cardiology, Lianshui People’s Hospital, Huaian, People’s Republic of ChinaCorrespondence: Gen-shan Ma, Department of Cardiology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, 210009, People’s Republic of China, Tel +86-13002580569, Email magenshan_D@163.comObjective: Dapagliflozin (DAPA) has been reported to have significant cardiac protective effects on heart failure (HF). However, the dose and time, as well as the underlying mechanisms, for DAPA treatment in acute myocardial infarction (AMI) remain controversial. The aim of this study aimed to assess the efficacy and safety of DAPA treatment along with an increased concentration gradient for AMI and explore the potential mechanisms.Methods: Non-diabetic Sprague-Dawley rats were used for establishing AMI models and then were treated with three different concentrations of DAPA [0.5 mg/kg, 1 mg/kg and 1.5 mg/kg, described as AMI+DAPA Low, AMI+DAPA Medium (Med) and AMI+DAPA High, respectively] for six weeks from the onsetting of AMI. Echocardiography, histological staining and Western blot were performed to assess the relevant cardiac protective effects. Mitochondrial biogenesis and myocardial apoptosis were evaluated via the electron microscopy and TUNEL assay, respectively, as well as the Immunoblotting. In vitro, H9c2 cells were subjected to hypoxic treatment to assess the efficacy of DAPA on mitochondrial biogenesis and apoptosis.Results: The medium dose of DAPA treatment could significantly reduce the infarct size (P < 0.01) and the echocardiography results showed that the MI-induced damage in cardiac function got partly repaired, showing no significant difference in left ventricle ejection fraction (LVEF) versus the Sham group (Sham vs AMI+DAPA Med group: 70.47% vs 61.73%). The Western blotting results confirmed the relevant benefits and the underlying mechanisms might be through the activation of PGAM5/Drp1 signaling pathway to normalize the mitochondrial fission and reduce cardiomyocyte apoptosis. Moreover, a medium dose of DAPA treatment could avoid increased damage to the bladder endothelium following higher treatment doses.Conclusion: Appropriate dose of DAPA treatment could improve the cardiac remodeling and reduce the cardiomyocyte apoptosis after AMI, without increased damage to bladder endothelium, which might be more preferred for MI patients without diabetes.Keywords: Dapagliflozin, acute myocardial infarction, mitochondrial fission, cardiomyocyte apoptosis

Dongjiu Li,1,&ast; Jiayin You,2,&ast; Chengyu Mao,1,&ast; En Zhou,1,&ast; Zhihua Han,1 Junfeng Zhang,1 Tiantian Zhang,1 Changqian Wang1 1Department of Cardiology, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, People’s Republic of China; 2Department of Emergency, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Tiantian Zhang; Changqian Wang, Email ZhangTT2022Dr@163.com; wangcqdr17@163.comObjective: Cardiomyocyte apoptosis critically contributes to ischemia reperfusion injury (IRI), which lacks effective therapeutic strategies. Circular RNAs (circRNAs) serve as novel diagnostic and therapeutic targets in various cardiovascular diseases. CircRNA Fbxl5 is one of the abundantly expressed circRNAs in the heart and its role in myocardial IRI remains elusive.Materials and Methods: Wild-type (WT) mice and neonatal mice ventricular myocytes (NMVMs) were used and subjected to myocardial IRI and anoxia reoxygenation (AR), respectively. Molecular and histological analyses and echocardiography were used to determine the extent of apoptosis, infarct size, and cardiac function.Results: We found that circRNA Fbxl5 was significantly upregulated in the myocardium, as well as in NMVMs subjected to AR. Knockdown of circRNA Fbxl5 ameliorated cardiomyocyte apoptosis, thereby decreasing infarct size and preserving cardiac function. Additionally, in vitro knockdown of circRNA Fbxl5 in NMVMs subjected to AR recapitulated the in vivo findings. Mechanistically, we identified that circRNA Fbxl5 directly sponged and suppressed the endogenous microRNA-146a (miR-146a), thereby weakening its inhibitory effect on MED1, which could further promote the apoptosis of cardiomyocytes.Conclusion: Our findings revealed a novel and critical role for circRNA Fbxl5 in regulating cardiomyocyte apoptosis, and added additional insight into circRNAs mediated during myocardial IRI. The underlying miR-146a-MED1 signaling serves as an important cascade in regulating the apoptosis of cardiomyocytes.Keywords: myocardial ischemia reperfusion injury, circular RNA, microRNA-146a, cardiomyocyte apoptosis

MicroRNAs (miRs) are reported to regulate myocardial infarction (MI). This study was performed to investigate the function and mechanism of miR-17-5p in myocardial remodelling after MI. Initially, a mouse model of MI was established and MI mice were infected with lentivirus antago-miR-17-5p vector. High expression of miR-17-5p was found in myocardial tissues after MI. After inhibiting miR-17-5p expression, myocardial fibrosis, scarring, and cardiomyocyte apoptosis were improved, LC3-II/LC3-I ratio and Beclin-1 expression were decreased but p62 expression was increased. The dual-luciferase assay suggested that miR-17-5p targeted STAT3 and negatively regulated its expression. Then, after inhibiting STAT3 expression using STAT3 inhibitor S31-201, the fibrosis, scarring, and cardiomyocyte apoptosis were deteriorated, along with the rise of LC3-II/LC3-I and Beclin-1 expression, the reduction of p62 expression and the reversion of MI attenuation. In conclusion, inhibition of miR-17-5p can inhibit myocardial autophagy through targeting STAT3 and then inhibit myocardial remodelling, thereby protecting the myocardium after MI.

Diabetic cardiomyopathy (DCM) is highly prevalent and increases the risk of heart failure and sudden death. Therefore, proper and effective treatments for DCM are in urgent demand. Danlou tablet (Dan) is reported to confer protective effects on several heart diseases. However, to our knowledge, whether Dan provides protection against DCM is unclear. In this study, we explored the effect of Dan on DCM with the in vitro DCM model using AC16 cardiomyocytes. We found that Dan treatment significantly reduced cardiomyocyte apoptosis and oxidative stress in high-glucose (HG)-treated cardiomyocytes, as evidenced by decreased Annexin V-FITC+ cardiomyocytes, intracellular reactive oxygen species (ROS) levels, Bax/Bcl2 ratio, and cleaved-Caspase3/Caspase3 ratio. Interestingly, Dan treatment caused a decreased level of microRNA-34a (miR-34a), which could enhance cardiomyocyte apoptosis. Furthermore, miR-34a mimic blocked Dan's effect in apoptosis prevention. Finally, we observed that the miR-34a mimic effectively decreased the level of sirtuin 1 (SIRT1), while the miR-34a inhibitor increased the level of SIRT1. And downregulation of SIRT1 effectively reversed the effect of miR-34a inhibitor on cardiomyocyte apoptosis. Taken together, our study showed that Dan prevented HG-induced cardiomyocyte apoptosis through downregulating miR-34a and upregulating SIRT1. Our study has provided experimental support for the potential use of Dan in treating DCM. Further detailed study of Dan and the underlying mechanisms may shed light on the prevention and treatment of DCM.

Although previous studies showed that long non-coding RNAs (lncRNAs) have critical roles in the pathogenesis of acute myocardial infarction (AMI), the underlying molecular mechanism that lncRNAs participate in MI remains unclear. Herein, we explored the expression of lncRNA HOX antisense non-coding RNA (HOTAIR) in the serum of MI patients and mouse model of AMI. Biological functions of HOTAIR in hypoxic H9c2 cells, the in vitro model of MI, were also assessed. RT-qPCR results showed that HOTAIR expression was downregulated in the serum of AMI patients and AMI mice. HOTAIR overexpression promoted H9c2 cell viability and inhibited cell apoptosis under hypoxic conditions. Mechanically, HOTAIR was regulated by miR-206 and FN1 was the direct target of miR-206. More importantly, miR-206 overexpression or FN1 knockdown reversed the effect of HOTAIR overexpression on H9c2 cell viability and apoptosis under hypoxic conditions. Therefore, targeting the HOTAIR/miR-206/FN1 axis may be a promising therapeutic method for MI. [ABSTRACT FROM AUTHOR]

Objective: To investigate the potential mechanisms of the protective effects of Buyang Huanwu decoction (BYHWD) on cardiomyocyte apoptosis after myocardial infarction (MI) and to provide the foundation for the clinical application of BYHWD in preventing and treating cardiomyocyte apoptosis-related disorders after MI. Methods: The MI rat model was established by ligation of the left anterior descending (LAD) coronary artery. After the 20-week treatment with BYHWD, the following parameters were assessed to investigate the protective effects of BYHWD on cardiomyocyte apoptosis after MI, both in vivo and in vitro: mortality rate; heart weight/body weight (HW/BW); transthoracic echocardiography measurements; histopathological analysis; immunohistochemistry (IHC) analysis; TUNEL apoptosis assay; caspase-3 activity assay; aldehyde dehydrogenase-2 (ALDH2) enzymatic activity assay; malondialdehyde (MDA) content analysis; western blot analysis; MTT assay; and Hoechst 33342/PI apoptosis assay. Results: The mortality of the MI rats was significantly reduced by BYHWD treatment. Furthermore, BYHWD treatment significantly improved the heart function and significantly reduced the HW/BW ratio. Histopathological analysis showed that BYHWD treatment significantly relieved MI-induced cardiac injury and significantly decreased collagen formation. The TUNEL apoptosis assay showed that treatment with BYHWD reduced the cardiomyocyte apoptosis of MI rats in a dose-dependent manner. Moreover, BYHWD treatment could significantly inhibit oxidative stress-induced neonatal cardiomyocyte apoptosis, which is consistent with the results of animal experiments in vivo. Interestingly, the ALDH2 activity and protein expression was significantly reduced in the MI model group, while the content of toxic aldehydes, including 4-HNE and MDA, was increased. Importantly, BYHWD enhanced the activity of ALDH2 and the expression of ALDH2 protein and attenuated the content of toxic aldehydes in a dose-dependent manner. Furthermore, we found that co-treatment with an ALDH2 inhibitor, disulfiram, partially inhibited the cardiomyocyte protective effects of BYHWD. Conclusions: Collectively, our results suggest that BYHWD exerted anti-apoptotic effects in cardiomyocytes after MI by enhancing the ALDH2 activity and protein expression and decreasing the toxic aldehyde content.

Hypoxia and reoxygenation (H/R) play a prevalent role in heart-related diseases. Histone demethylases are involved in myocardial injury. In this study, the mechanism of the lysine-specific histone demethylase 1A (KDM1A/LSD1) on cardiomyocyte apoptosis after myocardial ischemia-reperfusion injury (MIRI) was investigated. Firstly, HL-1 cells were treated with H/R to establish the MIRI models. The expressions of KDM1A and Sex Determining Region Y-Box Transcription Factor 9 (SOX9) in H/R-treated HL-1 cells were examined. The cell viability, markers of myocardial injury (LDH, AST, and CK-MB) and apoptosis (Bax and Bcl-2), and Caspase-3 and Caspase-9 protein activities were detected, respectively. We found that H/R treatment promoted cardiomyocyte apoptosis and downregulated KDM1A, and overexpressing KDM1A reduced apoptosis in H/R-treated cardiomyocytes. Subsequently, tri-methylation of lysine 4 on histone H3 (H3K4me3) level on the SOX9 promoter region was detected. We found that KDM1A repressed SOX9 transcription by reducing H3K4me3. Then, HL-1 cells were treated with CPI-455 and plasmid pcDNA3.1-SOX9 and had joint experiments with pcDNA3.1-KDM1A. We disclosed that upregulating H3K4me3 or overexpressing SOX9 reversed the inhibitory effect of overexpressing KDM1A on apoptosis of H/R-treated cardiomyocytes. In conclusion, KDM1A inhibited SOX9 transcription by reducing the H3K4me3 on the SOX9 promoter region and thus inhibited H/R-induced apoptosis of cardiomyocytes. [ABSTRACT FROM AUTHOR]

Jiang Zhu,1,&ast; Xia Zhang,2,&ast; Hong Xie,1 Yuye Wang,1 Xiaoxiao Zhang,1 Zhaoheng Lin3 1Department of Anesthesiology, The Second Affiliated Hospital of Soochow University, Suzhou, 215008, Jiangsu, People’s Republic of China; 2Department of Anesthesiology, Wuzhong People’s Hospital, Suzhou, Jiangsu, 215128, People’s Republic of China; 3Intensive Care Unit, People’s Hospital of Xishuangbanna Dai Nationality Autonomous Prefecture, Jinghong City, 666100, Yunnan, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Zhaoheng LinIntensive Care Unit, People’s Hospital of Xishuangbanna Dai Nationality Autonomous Prefecture, Galan South Road, Jinghong City, 666100, Yunnan, People’s Republic of ChinaTel +86691-2123836Fax +8615198406999Email linzh_med@163.comIntroduction: Doxorubicin (Dox) is an effective anticancer agent; however, its cardiotoxicity remains a challenge. Dysfunction of intracellular calcium ion (Ca2+) is implicated in the process of Dox-induced cardiomyocyte apoptosis. Although store-operated Ca2+ entry (SOCE) is suggested to be responsible for Ca2+ entry in cardiomyocytes, the direct role of store-operated Ca2+ channels in Dox-related cardiomyocyte apoptosis is unknown.Materials and Methods: Cardiomyocyte Stim1-specific knockout or overexpression mice were treated with Dox. Cardiomyocytes were pretreated with Stim1 adenovirus or siRNA followed by Dox incubation in vitro. Cardiac function and underlying mechanisms echocardiography were assessed via immunofluorescence, flow cytometry, real-time PCR, Western blotting and immunoprecipitation.Results: We observed the inhibition of Stim1 expression, association of Stim1 to Orai1 or Trpc1, and SOCE in Dox-treated mouse myocardium and cardiomyocytes. Orai1 and Trpc1 expression remained unchanged. Cardiomyocyte-specific deficiency of Stim1 exacerbated Dox-induced cardiac dysfunction and myocardial apoptosis. However, specific overexpression of Stim1 in the myocardium was associated with amelioration of cardiac dysfunction and myocardial apoptosis. In vitro, STIM1 knockdown potentiated Dox-induced AC16 human cardiomyocyte apoptosis. This apoptosis was attenuated by STIM1 upregulation. Moreover, STIM1 downregulation enhanced Dox-induced endoplasmic reticulum (ER) stress in cardiomyocytes. In contrast, STIM1 overexpression inhibited the activation of the above molecular markers of ER stress. Immunoprecipitation assay showed that STIM1 interacted with GRP78 in cardiomyocytes. This interaction was attenuated in response to Dox treatment.Conclusion: Our data demonstrate that cardiomyocyte STIM1 binding to GRP78 ameliorates Dox cardiotoxicity by inhibiting pro-apoptotic ER stress.Keywords: doxorubicin, cardiotoxicity, cardiomyocyte apoptosis, STIM1, endoplasmic reticulum stress

Cigarette smoking is an important risk factor for diabetes, cardiovascular disease and non-alcoholic fatty liver disease. The health risk associated with smoking can be aggravated by obesity. Smoking might also trigger cardiomyocyte (CM) apoptosis. Given that CM apoptosis has been implicated as a potential mechanism in the development of cardiomyopathy and heart failure, we characterize the key signaling pathways in nicotine plus high-fat diet (HFD)-induced CM apoptosis. Adult C57BL6 male mice were fed a normal diet (ND) or HFD and received twice-daily intraperitoneal (IP) injections of nicotine (0.75 mg/kg body weight [BW]) or saline for 16 weeks. An additional group of nicotine-treated mice on HFD received twice-daily IP injections of mecamylamine (1 mg/kg BW), a non-selective nicotinic acetylcholine receptor antagonist, for 16 weeks. Nicotine when combined with HFD led to a massive increase in CM apoptosis that was fully prevented by mecamylamine treatment. Induction of CM apoptosis was associated with increased oxidative stress and activation of caspase-2-mediated intrinsic pathway signaling coupled with inactivation of AMP-activated protein kinase (AMPK). Furthermore, nicotine treatment significantly (P

Abstract Objective Proinflammatory cytokine interleukin 17 (IL-17) is involved in ventricular remodeling, mainly of the left ventricle. This study was designed to explore the role of IL-17 played in the pathogenesis of right ventricular hypertrophy (RVH), aiming to provide a novel treatment target or diagnostic biomarker options for improving the care of RVH patients. Methods C57BL/6 mice were maintained in 10% O2 chamber or room air for four weeks. Right ventricular hypertrophy index (RVHI), RV/body weight ratio, pulmonary arteriolar remodeling determined by percent media thickness (%MT), and the cardiomyocyte diameter of RV were evaluated. Mice were treated with exogenous recombinant mouse IL-17 (rmIL-17, 1 μg per dose twice a week) for four weeks. H9c2 cardiomyocytes were cultured and treated with IL-17 (10 ng/mL) and STAT3 inhibitor (10 ng/mL) either under normoxia (21% O2, 5% CO2, 74% N2) or under hypoxia (3% O2, 5% CO2, 92% N2). Cardiomyocyte viability was assessed by Cell counting kit 8 (CCK-8) assay. The mRNA level was detected by RT-PCR, where as the protein expression was measured by Western blot, immunohistochemistry, and immunofluorescent analyses. Results In vivo experiments showed that IL-17 did not affect the pulmonary artery under normoxia, after treatment with rmIL-17, %MT was not changed, while RVHI and the RV/body weight ratio were increased, indicating that IL-17 directly induced right ventricular hypertrophy. In a time-course study, the mice were exposed to hypoxia for 0, 1, 2, 3, 4 weeks, respectively. We found that the expression of IL-17 was gradually upregulated in RV tissue in a time-dependent manner after one week of hypoxia exposure, especially at the third and fourth week. Cardiomyocyte hypertrophy and apoptosis were observed after the exposure of the mice to hypoxia for four weeks, rmIL-17 further aggravated the hypoxia-induced cardiomyocyte hypertrophy and apoptosis. The expression of p-STAT3 in the IL-17-deficient mice was lower than in the wild-type mice. In vitro, IL-17 inhibited cardiomyocyte viability and induced cardiomyocyte apoptosis via STAT3 under both normoxic and hypoxic conditions. Conclusions These findings support a role for IL-17 as a mediator in the pathogenesis RVH, which might be considered as a potential novel anti-inflammation therapeutic strategy or diagnostic biomarker for RVH.

Sepsis-induced myocardial dysfunction is a common complication in septic patients. To date, a limited number of biomarkers that could predict cardiomyocyte apoptosis have been explored. In this study, we successfully established a cecal ligation and puncture (CLP)-induced septic model, and it was found that miR-501-5p expression was down-regulated in peripheral blood samples of septic patients with cardiac dysfunction, lipopolysaccharide (LPS)-induced cardiomyocytes, and the myocardium and peripheral blood in the septic model. Moreover, it was revealed that miR-501-5p overexpression could increase left ventricular diastolic pressure (LVDP), fractional shortening (FS), ejection fraction (EF), and maximum rate of the rise of left ventricular pressure (+dp/dt) in vivo, while it decreased the levels of myocardial injury-related indicators. In addition, LPS induction accelerated apoptosis and elevated the inflammation in HL-1 and HCM cells, which could be reversed by miR-501-5p overexpression. Mechanistically, we considered nuclear receptor subfamily 4 group A member 3 (NR4A3) as the target of miR-501-5p, and it was found that miR-501-5p prevented the binding between NR4A3 and Bcl-2. It was found that miR-501-5p exerted an inhibitory effect on cardiomyocyte apoptosis and inflammation in a NR4A3-dependent manner. Overall, our results may provide evidence for consideration of miR-501-5p in the therapy of sepsis. [ABSTRACT FROM AUTHOR]

Abstract Objective Emerging articles have profiled the relations between microRNAs and viral myocarditis. This research was unearthed to explore the capacity of miR‐425‐3p on cardiomyocyte apoptosis in mice with viral myocarditis and its mechanism. Methods A total of 120 mice were classified into 4 groups in a random fashion (n = 30). The mice were intraperitoneally injected with coxsackievirus type B3 (CVB3) to induce myocarditis. On the 7th day after CVB3 infection, 10 mice in each group were euthanized to assess the heart function indices of mice, observe the pathological conditions, detect myocardial tissue apoptosis, and measure the inflammatory factor levels in myocardial tissues. Expression of miR‐425‐3p, transforming growth factor (TGF‐β1), and apoptosis‐associated proteins in myocardial tissues was determined. The remaining 20 mice in each group were used for survival observation. The luciferase activity assay was implemented to validate the relationship between miR‐425‐3p and TGF‐β1. miR‐425‐3p mimic was transfected into mouse cardiomyocytes HL‐1 and then infected with CVB3 to further verify the regulatory effect of miR‐425‐3p on the cardiomyocyte apoptosis in viral myocarditis. Results miR‐425‐3p was lowly expressed in myocardial tissues of mice with viral myocarditis. Overexpressed miR‐425‐3p improved the cardiac function, alleviated pathological conditions, reduced cardiomyocyte apoptosis, decreased Bax and cleaved Caspase‐3 expression, elevated Bcl‐2 expression, decreased levels of inflammatory factors and improved survival rate of mice with viral myocarditis. Luciferase activity assay verified that miR‐425‐3p could bind to TGF‐β1, and overexpressed miR‐425‐3p suppressed TGF‐β1, p‐smad2/smad2 and p‐smad3/smad3 expression. In vitro experiments further verified that overexpression of miR‐425‐3p inhibited the apoptosis of CVB3‐HL‐1 cells, and the addition of TGF‐β1 would reverse this effect. Conclusion Our research indicates that miR‐425‐3p is poorly expressed in myocardial tissues of mice with viral myocarditis. Overexpressed miR‐425‐3p inhibits cardiomyocyte apoptosis and myocardial inflammation in mice with viral myocarditis as well as improves their survival rates through suppressing the TGF‐β1/smad axis.

Increasing evidence suggests that mitochondrial microRNAs (miRNAs) are implicated in the pathogenesis of cardiovascular diseases; however, their roles in ischemic heart disease remain unclear. Herein, we demonstrate that miR-146a is enriched in the mitochondrial fraction of cardiomyocytes, and its level significantly decreases after ischemic reperfusion (I/R) challenge. Cardiomyocyte-specific knockout of miR-146a aggravated myocardial infarction, apoptosis, and cardiac dysfunction induced by the I/R injury. Overexpression of miR-146a suppressed anoxia/reoxygenation-induced cardiomyocyte apoptosis by inhibiting the mitochondria-dependent apoptotic pathway and increasing the Bcl-2/Bax ratio. miR-146a overexpression also blocked mitochondrial permeability transition pore opening and attenuated the loss of mitochondrial membrane potential and cytochrome c leakage; meanwhile, miR-146a knockdown elicited the opposite effects. Additionally, miR-146a overexpression decreased cyclophilin D protein, not mRNA, expression. The luciferase reporter assay revealed that miR-146a binds to the coding sequence of the cyclophilin D gene. Restoration of cyclophilin D reversed the inhibitory action of miR-146a on cardiomyocyte apoptosis. Furthermore, cardiomyocyte-specific cyclophilin D deletion completely abolished the exacerbation of myocardial infarction and apoptosis observed in miR-146a cardiomyocyte-deficient mice. Collectively, these findings demonstrate that nuclear miR-146a translocates into the mitochondria and regulates mitochondrial function and cardiomyocyte apoptosis. Our study unveils a novel role for miR-146a in ischemic heart disease.

Abstract Background Gestational diabetes mellitus is a risk factor for congenital heart defects. The article aimed to investigate the expression and roles of MST1, YAP1, Last1/2 and Survivin in modulating HG-induced cardiomyocyte apoptosis and maternal diabetes-induced heart abnormality. Methods Diabetes mellitus was induced in rats using streptozotocin. The protein expression and phosphorylation analysis in fetal heart tissue was assessed by western blot and immunohistochemical staining. Hoechst 33342 staining assay was performed to explore H9C2 apoptosis. The gene and protein expression in H9C2 cells was assessed by quantitative PCR and western blot. Knockdown of gene expression was assessed by RNA interference. Results Our results revealed that increased MST1 protein levels in the heart tissues of the offspring of diabetic rats in vivo and in H9C2 cardiomyocytes under HG treatment in vitro, respectively. Knockdown and overexpression experiments showed that MST1 played a key role in mediating HG-induced apoptosis in cardiomyocytes. Downregulation of YAP1 was associated with HG-induced, MST1-mediated cardiomyocyte apoptosis. Further study showed that MST1 downregulated the protein level of YAP1 through mediation of YAP1 phosphorylation on Ser127 and Ser397; this process also required LATS1/2 participation. MST1 overexpression increased the phosphorylation levels of LATS1/2, which were also shown to be increased in the heart tissues of diabetic offspring. We also found that YAP1 mediated the expression of Survivin during HG-induced apoptosis, and the Survivin-inhibitor YM155 partially inhibited the role of YAP1 in suppressing apoptosis induced by HG in cardiomyocytes. Conclusion These findings reveal a regulatory mechanism of MST1/YAP1/Survivin signaling in modulating cardiomyocyte apoptosis in vitro and maternal diabetes-induced congenital heart defects in vivo.

Context Danshen, the dried root and rhizome of Salvia miltiorrhiza Bunge (Labiatae) and honghua, the dried flower of Carthamus tinctorius L. (Compositae) as the herb pair was used to treat cardiovascular diseases (CVD). Objective To study the effects of DHHP on MIRI and mechanisms based on apoptosis and mitochondria. Materials and Methods 36 SD rats (n = 6) were randomly divided into control group (Con), the ischaemia-reperfusion group (IR), positive control (Xinning tablets, XNT, 1 g/kg/d) and DHHP (1.2, 2.4, and 4.8 g/kg/d). Except for Con, the other groups were intragastrically administrated for 5 d, the rat hearts were isolated to establish the MIRI model in vitro for evaluating the effects of DHHP on MIRI. 24 SD rats (n = 6) were randomly divided into Con, IR, DPPH2.4 (2.4 g/kg/d) and DPPH 2.4 + Atractyloside (ATR) (2.4 + 5 mg/kg/d), administered intragastrically for 5 d, then treated with ATR (5 mg/kg/d) by intraperitoneal injection in DPPH2.4 + ATR group, took rat hearts to establish MIRI model in vitro for revealing mechanism. Results Myocardial infarct sizes were, respectively, 0.35%, 40.09%, 15.84%, 30.13%, concentrations of NAD+ (nmol/gw/w) were 144, 83, 119, and 88, respectively, in Con, IR, DHHP2.4, DHHP2.4 + ATR group. Cleaved caspase-3 were 0.3, 1.6, 0.5 and 1.3% and cleaved caspase-9 were 0.2, 1.1, 0.4 and 0.8%, respectively, in Con, IR, DHHP2.4 and DHHP2.4 + ATR group. The beneficial effects of DHHP on MIRI were reversed by ATR. Conclusions The improvement of MIRI by DHHP may be involved in inhibiting MPTP opening, decreasing oxidative damage, alleviating ischaemic injury and inhibiting cardiomyocyte apoptosis.

PIWI‐interacting RNAs (piRNAs) are abundantly expressed in heart. However, their functions and molecular mechanisms during myocardial infarction remain unknown. Here, a heart‐apoptosis‐associated piRNA (HAAPIR), which regulates cardiomyocyte apoptosis by targeting N‐acetyltransferase 10 (NAT10)‐mediated N4‐acetylcytidine (ac4C) acetylation of transcription factor EC (Tfec) mRNA transcript, is identified. HAAPIR deletion attenuates ischemia/reperfusion induced myocardial infarction and ameliorate cardiac function compared to WT mice. Mechanistically, HAAPIR directly interacts with NAT10 and enhances ac4C acetylation of Tfec mRNA transcript, which increases Tfec expression. TFEC can further upregulate the transcription of BCL2‐interacting killer (Bik), a pro‐apoptotic factor, which results in the accumulation of Bik and progression of cardiomyocyte apoptosis. The findings reveal that piRNA‐mediated ac4C acetylation mechanism is involved in the regulation of cardiomyocyte apoptosis. HAAPIR‐NAT10‐TFEC‐BIK signaling axis can be potential target for the reduction of myocardial injury caused by cardiomyocyte apoptosis in ischemia heart diseases. [ABSTRACT FROM AUTHOR]

Acute myocardial infarction (AMI) represents the acute manifestation of coronary artery disease. In recent years, microRNAs (miRNAs) have been extensively studied in AMI. This study focused on the role of miR-431-5p in AMI and its effect on cardiomyocyte apoptosis after AMI. The expression of miR-431-5p was analyzed by quantitative real-time PCR (qRT-PCR). By interfering with miR-431-5p in hypoxia-reoxygenation (H/R)-induced HL-1 cardiomyocytes, the effect of miR-431-5p on cardiomyocyte apoptosis after AMI was examined. The interaction between miR-431-5p and selenoprotein T (SELT) mRNA was verified by dual-luciferase reporter assay. Cell apoptosis was determined by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and flow cytometry. Cell viability was examined by 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide (MTT) assay. The results of qRT-PCR showed that the expression of miR-431-5p in AMI myocardial tissues and H/R-induced HL-1 cardiomyocytes was significantly increased. After interfering with miR-431-5p, the expression of SELT in HL-1 cells was up-regulated, cell apoptosis was decreased, cell viability was increased, and lactate dehydrogenase (LDH) activity was decreased. The dual-luciferase reporter assay confirmed the targeting relationship between miR-431-5p and SELT1 3’ untranslated region (UTR). In H/R-induced HL-1 cells, the simultaneous silencing of SELT and miR-431-5p resulted in a decrease of Bcl-2 expression, an increase of Bax expression, and an increase of cleaved-caspase 3 expression compared with silencing miR-431-5p alone. Also, cell viability was decreased, while LDH activity was increased by the simultaneous silencing of SELT and miR-431-5p. Interfering miR-431-5p protected cardiomyocytes from AMI injury via restoring the expression of SELT, providing new ideas for the treatment of AMI. [ABSTRACT FROM AUTHOR]

Objective To study the effect and mechanism of total astragalosides(ASTs) on myocardial cell apoptosis and mitochondrial membrane potential in rats with heart failure. Methods Rats were divided into control group(normal), heart failure group(model), AST low, medium and high intervention group (10, 20 and 40 mg/kg intragastric administration) and 12 rats in each group. Cardiac function was measured in rats. Myocardial tissue was taken from rats, apoptosis was detected by TUNEL assay, the activity of SOD was detected by xanthine oxidze method, the activity of GSH-PX was determined by dithio-dinitromethylbenzene method, MDA content was determined by thiobarbituric acid method, the mitochondrial membrane potential was measured by JC-1 method. Western blot was used to detect the expression levels of c-caspase-3, c-caspase-9, p-AKT, p-p38MAPK and Cyt-C in mitochondria and cytoplasm. Results Compared with normal group, LVSP,+dp/dtmax,-dp/dtmax in model group decreased(P＜0.05),the apoptotic rate and the level of c-caspase-3 and c-caspase-9 protein increased(P＜0.05), the activities of SOD and GSH-PX decreased(P＜0.05), the content of MDA increased(P＜0.05), the mitochondrial membrane potential decreased(P＜0.05), the level of Cyt-C protein in mitochondria decreased(P＜0.05), Cyt-c protein level in cytoplasm increased(P＜0.05), the level of p-AKT decreased, the level of p-p38MAPK increased(P＜0.05). Compared with model group, LVSP, +dp/dtmax,-dp/dtmax increased in AST-L, AST-M and AST-H groups, the apoptotic rate and c-caspase-3,c-caspase-9 protein levels decreased, the activities of SOD and GSH-PX increased, the content of MDA decreased, the mitochondrial membrane potential increased, the level of Cyt-C protein in mitochondria increased, Cyt-c protein level in cytoplasm decreased, the level of p-AKT increased, the level of p-p38 MAPK decreased, the higher the concentration of total astragalosides is, the greater the effect on heart failure rat model. Conclusions Total astragalosides inhibit cardiomyocyte apoptosis in rats with heart failure. The mechanism may be related to the increase of mitochondrial membrane potential and the influence of AKT and p38MAPK signaling pathways.

Diabetic cardiomyopathy (DCM) triggers a detrimental shift in mitochondrial dynamics, characterized by increased fission and decreased fusion, contributing to cardiomyocyte apoptosis and cardiac dysfunction. This study investigated the impact of modulating mitochondrial dynamics on DCM outcomes and underlying mechanisms in a mouse model. DCM induction led to upregulation of fission genes (Drp1, Mff, Fis1) and downregulation of fusion genes (Mfn1, Mfn2, Opa1). Inhibiting fission with Mdivi-1 or promoting fusion with Ginsenoside Rg1 preserved cardiac function, as evidenced by improved left ventricular ejection fraction (LVEF), fractional shortening (FS), and E/A ratio. Both treatments also reduced infarct size and attenuated cardiomyocyte apoptosis, indicated by decreased caspase-3 activity. Mechanistically, Mdivi-1 enhanced mitochondrial function by improving mitochondrial membrane potential, reducing reactive oxygen species (ROS) production, and increasing ATP generation. Ginsenoside Rg1 also preserved mitochondrial integrity and function under hypoxic conditions in HL-1 cardiomyocytes. These findings suggest that restoring the balance of mitochondrial dynamics through pharmacological interventions targeting either fission or fusion may offer a promising therapeutic strategy for mitigating MI-induced cardiac injury and improving patient outcomes., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Danshen, the dried root and rhizome of Salvia miltiorrhiza Bunge (Labiatae) and honghua, the dried flower of Carthamus tinctorius L. (Compositae) as the herb pair was used to treat cardiovascular diseases (CVD). To study the effects of DHHP on MIRI and mechanisms based on apoptosis and mitochondria. 36 SD rats (n = 6) were randomly divided into control group (Con), the ischaemia-reperfusion group (IR), positive control (Xinning tablets, XNT, 1 g/kg/d) and DHHP (1.2, 2.4, and 4.8 g/kg/d). Except for Con, the other groups were intragastrically administrated for 5 d, the rat hearts were isolated to establish the MIRI model in vitro for evaluating the effects of DHHP on MIRI. 24 SD rats (n = 6) were randomly divided into Con, IR, DPPH2.4 (2.4 g/kg/d) and DPPH 2.4 + Atractyloside (ATR) (2.4 + 5 mg/kg/d), administered intragastrically for 5 d, then treated with ATR (5 mg/kg/d) by intraperitoneal injection in DPPH2.4 + ATR group, took rat hearts to establish MIRI model in vitro for revealing mechanism. Myocardial infarct sizes were, respectively, 0.35%, 40.09%, 15.84%, 30.13%, concentrations of NAD+ (nmol/gw/w) were 144, 83, 119, and 88, respectively, in Con, IR, DHHP2.4, DHHP2.4 + ATR group. Cleaved caspase-3 were 0.3, 1.6, 0.5 and 1.3% and cleaved caspase-9 were 0.2, 1.1, 0.4 and 0.8%, respectively, in Con, IR, DHHP2.4 and DHHP2.4 + ATR group. The beneficial effects of DHHP on MIRI were reversed by ATR. The improvement of MIRI by DHHP may be involved in inhibiting MPTP opening, decreasing oxidative damage, alleviating ischaemic injury and inhibiting cardiomyocyte apoptosis. [ABSTRACT FROM AUTHOR]

Sepsis-induced cardiac injury (SIC) is one of the most common complications in the intensive care unit (ICU) with high morbidity and mortality. Mitochondrial dysfunction is one of the main reasons for SIC, and Interleukin-13 (IL-13) is a master regulator of mitochondria biogenesis. The aim of the present study was to investigate the role of IL-13 in SIC and explore the underlying mechanism. It was found that reactive oxygen species (ROS) production and apoptosis were significantly increased in lipopolysaccharide (LPS)-stimulated primary cardiomyocytes, which was accompanied with obvious mitochondria dysfunction. The results of RNA-sequencing (RNA-seq), mitochondrial membrane potential, fatty acid uptake and oxidation rate suggested that treatment with IL-13 could restore the function and morphology of mitochondria, indicating that it played an important role in protecting septic cardiomyocytes. These findings demonstrated that IL-13 alleviated sepsis-induced cardiac inflammation and apoptosis by improving mitochondrial fatty acid uptake and oxidation, suggesting that IL-13 may prove to be a potential promising target for SIC treatment.

The involvement of cardiomyopathy during sepsis means higher mortality and prolonged length of hospital stay. Many efforts have been made to alleviate the apoptosis of cardiomyocytes in sepsis. The huge potential of IL-13 in tissue repair has attracted increasing attention. In the present study, we used LPS-treated mice or primary cardiomyocytes as a sepsis model to explore the anti-apoptotic ability of IL-13. It was found that an increased level of exogenous IL-13 was beneficial to the recovery of heart function in sepsis, and this anti-apoptotic effect of IL-13 was probably through enhancing the phosphorylation of STAT3 Ser727. In addition, we identified that the heart protective effect of IL-13 was associated with type 2 innate lymphocytes (ILC2). All these findings may provide a potential promising treatment for sepsis-induced cardiomyopathy.

Lipid droplets (LDs), which are neutral lipid storage organelles, are important for lipid metabolism and energy homeostasis. LD lipolysis and interactions with mitochondria are tightly coupled to cellular metabolism and may be potential targets to buffer the effects of excessive toxic lipid species levels. Acetylcholine (ACh), the major neurotransmitter of the vagus nerve, exhibits cardioprotective effects. However, limited research has focused on its effects on LD lipolysis and the LD-mitochondria association in fatty acid (FA) overload models. Here, we reveal that palmitate (PA) induces an increase in expression of the FA transport protein cluster of differentiation 36 (CD36) and LD formation; remarkably reduces the expression of lipases involved in triacylglycerol (TAG) lipolysis, such as adipose triglyceride lipase (ATGL), hormone-sensitive lipase (HSL) and monoacylglycerol lipase (MGL); impairs LD-mitochondria interaction; and decreases perilipin 5 (PLIN5) expression, resulting in LD accumulation and mitochondrial dysfunction, which ultimately lead to cardiomyocyte apoptosis. ACh significantly upregulates PLIN5 expression and improved LD lipolysis and the LD-mitochondria association. Moreover, ACh reduces CD36 expression, LD deposition and mitochondrial dysfunction, ultimately suppressing apoptosis in PA-treated neonatal rat ventricular cardiomyocytes (NRVCs). Knockdown of PLIN5, which plays a role in LD-mitochondria contact site formation, abolishes the protective effects of ACh in PA-treated NRVCs. Thus, ACh protects cardiomyocytes from PA-induced apoptosis, at least partly, by promoting LD lipolysis and activating LD-mitochondria interactions via PLIN5. These findings may aid in developing novel therapeutic approaches that target LD lipolysis and PLIN5-mediated LD-mitochondria interactions to prevent or alleviate lipotoxic cardiomyopathy. [ABSTRACT FROM AUTHOR]

• Activation of UPRmt, along with mitochondrial dysfunction, occurred in PA-induced AC16 cardiomyocytes; both of these effects were reversed by baicalein. • Inhibiting or knockdown NRF2 abolished the beneficial effects of baicalein on UPRmt and antioxidant regulation. • Deficiency of NRF2 aggravated UPRmt activation and mitochondrial dysfunction in PA treated cardiomyocytes. • In db/db mice, baicalein inhibited UPRmt, enhanced antioxidant capacity and attenuated mitochondrial and cardiac dysfunction in a manner related to activation of NRF2. 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. The present research designed to clarify the role of baicalein in lipotoxicity-induced myocardial apoptosis and investigated the UPRmt-related mechanism. 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. 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. 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. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract Background Our previous study showed that knockdown of long noncoding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) attenuated myocardial apoptosis in mouse acute myocardial infarction (AMI). This study aims to explore whether MALAT1 enhanced cardiomyocyte apoptosis via autophagy regulation and the underlying mechanisms of MALAT1 regulating autophagy. Methods Cardiomyocytes were isolated from neonatal mice and then stimulated with hypoxia/reoxygenation (H/R) injury to mimic AMI. The autophagy level was assessed using GFP-LC3 immunofluorescence and western blot analysis of autophagy-related proteins. RNA pull-down and RNA immunoprecipitation (RIP) was performed to analyze the binding of MALAT1 and EZH2. Chromatin immunoprecipitation (ChIP) assay was performed to analyze the binding of TSC2 promoter and EZH2. The cell apoptosis was evaluated using TUNEL staining and western blot analysis of apoptosis-related proteins. Results H/R injury increased MALAT1 expression in cardiomyocytes. Furthermore, MALAT1 overexpression inhibited, whereas MALAT1 knockdown enhanced the autophagy of cardiomyocytes. Moreover, MALAT1 overexpression recruited EZH2 to TSC2 promoter regions to elevate H3K27me3 and epigenetically inhibited TSC2 transcription. Importantly, TSC2 overexpression suppressed mTOR signaling and then activated the autophagy. Further results showed that MALAT1 inhibited proliferation and enhanced apoptosis of cardiomyocytes through inhibiting TSC2 and autophagy. Conclusion These findings demonstrate that the increased MALAT1 expression induced by H/R injury enhances cardiomyocyte apoptosis through autophagy inhibition by regulating TSC2-mTOR signaling.

Abstract Background Adiponectin exerts several beneficial cardiovascular effects, however their specific molecular mechanisms require additional understanding. This study investigated the mechanisms of adiponectin action in the heart during high fat diet (HFD) feeding or in palmitate (PA) treated H9c2 cardiomyoblasts. Methods 6-week-old male adiponectin knock out (Ad-KO) mice were fed chow or 60% HFD for 6 weeks then received saline or recombinant adiponectin (3μg/g body weight) for an additional 2 weeks. After acute insulin stimulation (4 U/kg), tissue and serum samples were collected for analysis. H9c2 cardiomyocytes were treated ±0.1 mM PA, the adiponectin receptor agonist AdipoRon, or the antioxidant MnTBAP then assays to analyze reactive oxygen species (ROS) production and cell death were conducted. To specifically determine the mechanistic role of S1P, gain and loss of function studies were conducted with adding S1P to cells or the inhibitors THI and SKI-II, respectively. Results HFD feeding induced cardiac insulin resistance in Ad-KO mice, which was reversed following replenishment of normal circulating adiponectin levels. In addition, myocardial total triglyceride was elevated by HFD and lipidomic analysis showed increased levels of ceramides and sphingosine-1-phosphate (S1P), with only the latter being corrected by adiponectin administration. Similarly, treatment of H9C2 cardiomyoblasts with PA led to a significant increase of intracellular S1P but not in conditioned media whereas AdipoRon significantly increased S1P production and secretion from cells. AdipoRon or the antioxidant MnTBAP significantly reduced PA-induced cell death. Gain and loss of function studies suggested S1P secretion and autocrine receptor activation mediated the effect of AdipoRon to attenuate PA-induced ROS production and cell death. Conclusion Our data establish adiponectin signaling-mediated increase in S1P secretion as a mechanism via which HFD or PA induced cardiomyocyte lipotoxicity, leading to insulin resistance and cell death, is attenuated.

Objective: Proinflammatory cytokine interleukin 17 (IL-17) is involved in ventricular remodeling, mainly of the left ventricle. This study was designed to explore the role of IL-17 played in the pathogenesis of right ventricular hypertrophy (RVH), aiming to provide a novel treatment target or diagnostic biomarker options for improving the care of RVH patients.Methods: C57BL/6 mice were maintained in 10% O2 chamber or room air for four weeks. Right ventricular hypertrophy index (RVHI), RV/body weight ratio, pulmonary arteriolar remodeling determined by percent media thickness (%MT), and the cardiomyocyte diameter of RV were evaluated. Mice were treated with exogenous recombinant mouse IL-17 (rmIL-17, 1 μg per dose twice a week) for four weeks. H9c2 cardiomyocytes were cultured and treated with IL-17 (10 ng/mL) and STAT3 inhibitor (10 ng/mL) either under normoxia (21% O2, 5% CO2, 74% N2) or under hypoxia (3% O2, 5% CO2, 92% N2). Cardiomyocyte viability was assessed by Cell counting kit 8 (CCK-8) assay. The mRNA level was detected by RT-PCR, where as the protein expression was measured by Western blot, immunohistochemistry, and immunofluorescent analyses.Results: In vivo experiments showed that IL-17 did not affect the pulmonary artery under normoxia, after treatment with rmIL-17, %MT was not changed, while RVHI and the RV/body weight ratio were increased, indicating that IL-17 directly induced right ventricular hypertrophy. In a time-course study, the mice were exposed to hypoxia for 0, 1, 2, 3, 4 weeks, respectively. We found that the expression of IL-17 was gradually upregulated in RV tissue in a time-dependent manner after one week of hypoxia exposure, especially at the third and fourth week. Cardiomyocyte hypertrophy and apoptosis were observed after the exposure of the mice to hypoxia for four weeks, rmIL-17 further aggravated the hypoxia-induced cardiomyocyte hypertrophy and apoptosis. The expression of p-STAT3 in the IL-17-deficient mice was lower than in the wild-type mice. In vitro, IL-17 inhibited cardiomyocyte viability and induced cardiomyocyte apoptosis via STAT3 under both normoxic and hypoxic conditions.Conclusions: These findings support a role for IL-17 as a mediator in the pathogenesis RVH, which might be considered as a potential novel anti-inflammation therapeutic strategy or diagnostic biomarker for RVH. [ABSTRACT FROM AUTHOR]

The adult heart has a limited capacity to replace or regenerate damaged cardiac tissue following severe myocardial injury. Thus, therapies facilitating the induction of cardiac regeneration holds great promise for the treatment of end-stage heart failure, and for pathologies invoking severe cardiac dysfunction as a result of cardiomyocyte death. Recently, a number of studies have demonstrated that cardiac regeneration can be achieved through modulation and/or reprogramming of cardiomyocyte proliferation, differentiation, and survival signaling. Non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), are reported to play critical roles in regulating key aspects of cardiomyocyte physiologic and pathologic signaling, including the regulation of cardiac regeneration both in vitro and in vivo. In this review, we will explore and detail the current understanding of ncRNA function in cardiac regeneration, and highlight established and novel strategies for the treatment of heart failure through modulation of ncRNAs-driven cardiac regeneration. [ABSTRACT FROM AUTHOR]