H9c2 Cells Research Articles

Txnip promotes autophagic apoptosis in diabetic cardiomyopathy by upregulating FoxO1 and its acetylation

Autophagy dysfunction and apoptosis exacerbate the risk of heart failure in patients with diabetic cardiomyopathy (DCM). However, the interactions between autophagy and apoptosis in DCM and their underlying mechanisms remain poorly understood. This study induced type 1 DCM in C57BL/6 mice via streptozotocin injection and exposed H9C2 cells to high glucose to investigate these mechanisms. The study revealed a significant elevation in autophagic vesicles and compromised autophagic flux, accompanied by pronounced myocardial cell apoptosis in the myocardium of diabetic mice. Long-term exposure to high glucose in H9C2 cells led to enhanced autophagosome formation and impaired autophagic flux, while inhibition of autophagy with 3-MA reduced cell apoptosis. Additionally, we observed an increase in Txnip expression in the myocardium of diabetic mice and in high glucose-treated H9C2 cells, which regulates autophagic apoptosis in high glucose-treated H9C2 cells. Furthermore, Txnip regulates autophagic apoptosis through the modulation of forkhead box-1 (FoxO1) expression and acetylation. Prolonged high glucose exposure resulted in increased levels of phosphorylated sirtuin 1 (SIRT1) and reduced SIRT1/FoxO1 interaction, changes that were ameliorated by Txnip knockdown. Txnip overexpression elevated FoxO1 levels, which could be suppressed by NAC and GSH. These findings revealed that Txnip mediates autophagic apoptosis in DCM by upregulating FoxO1 via ROS and enhancing FoxO1 acetylation through the suppression of SIRT1 activity. The discovery of this new mechanism provides new perspectives and potential therapeutic targets for understanding and treating DCM.

Mesenchymal stem cell-derived exosomal mir-21-5p inhibits YAP1 expression and improves outcomes in myocardial infarction

BackgroundMyocardial infarction (MI) remains a significant global health concern, characterized by cardiomyocyte apoptosis and adverse ventricular remodeling. Nevertheless, the interplay between exosomal miR-21-5p and Yes-associated protein 1 (YAP1) in the context of MI remains unexplored.MethodsRat mesenchymal stem cells (MSCs) and H9c2 cardiomyocytes were cultured, characterized, and instrumental in our experiments. Exosomes were meticulously isolated, and their identity confirmed. The internalization of these exosomes by H9c2 cells was assessed, while RNA and protein expression were quantified using Quantitative Real-Time PCR and Western blot, respectively. MTT assay was implemented for cell viability, and apoptosis was evaluated via flow cytometric analysis. To elucidate gene interactions, we conducted microarray profiling of miRNA expression, dual luciferase reporter assays, and RNA Immunoprecipitation.ResultsMSC-derived exosomes exhibited a remarkable capacity to attenuate hypoxia-induced inflammation and apoptosis in H9c2 cells. Notably, these exosomes significantly upregulated miR-21-5p levels within H9c2 cells, and the abrogation of miR-21-5p function abated their protective effects. Through computational analysis, we unveiled a miR-21-5p binding site in the 3’UTR of YAP1, which directly inhibited YAP1 expression. Importantly, the inhibition of YAP1 effectively reinstated the protective effects of exosomes in cells with impaired exosomal miR-21-5p.ConclusionThis study underscores the pivotal role played by MSC-derived exosomes in safeguarding against MI, primarily by mediating the transfer of miR-21-5p, which targets YAP1 signaling pathways.Clinical trial numberN/A.

Biological evaluation of sophoridine by interaction with plasma transport protein and protective effects in cardiomyocytes

Numerous studies have demonstrated the protective benefits of sophoridine, a bioactive alkaloid, on cell damage. However, its primary biological properties such as interaction with plasma protein, which serves as the primary drug carrier, and its cardioprotective properties are still unknown. In the present study, we aimed to analyze the binding characteristics of sophoridine with alpha-2-macroglobulin (α2M) by spectroscopic and theoretical studies. Then, the cardioprotective effects of sophoridine on myocardial ischemia/reperfusion (MI/R) injury in vitro were investigated using H9c2 cardiomyocytes. The results reveal that one molecule of sophoridine favorably binds to one molecule of α2M dominantly through interaction with hydrophobic amino acid residues (VAL758, PHE735, PHE735, and TRP739). Also, sophoridine leads to partial changes in the structure of this carrier protein in the vicinity of TRP739 residue. Cellular assays exhibit that sophoridine recovered cell viability, membrane leakage, and apoptosis induced by MI/R injury. It was detected that sophoridine could mitigate the oxidative stress and intrinsic apoptosis pathway through regulation of Bax, Bcl-2, and caspase. ELISA analysis also exhibits that sophoridine upregulates phosphorylation of Akt and PI3K in H9c2 cells. Our findings suggest that sophoridine could show favorable plasma protein interaction and promising cardioprotection against MI/R injury mediated by the upregulation of PI3K/AKT signaling pathway.

Alteration of N-glycosylation of CDON promotes H2O2-induced DNA damage in H9c2 cardiomyocytes

Protein glycosylation is involved in DNA damage. Recently, DNA damage has been connected with the pathogenesis of heart failure. Cell adhesion associated, oncogene regulated (CDON), considered as an N-linked glycoprotein, is a transmembrane receptor for modulating cardiac function. But the role of CDON and its glycosylation in DNA damage remains unknown. In this study, we found that the knockdown of CDON caused DNA double-strand breaks as indicated by an increase in phosphorylated histone H2AX (γH2AX) protein level, immunofluorescent intensity of γH2AX and tail DNA moment in H9c2 cardiomyocytes. Conversely, overexpression of CDON led to decreasing DNA damage induced by hydrogen peroxide (H2O2) and upregulating the expression of genes related to DNA repair pathways-homologous recombination (HR) and non-homologous end joining (NHEJ). Moreover, we expressed nine predicted N-glycosylation site mutants in H9c2 cells prior to treatment with H2O2. The results showed that mutation of N-glycosylation sites (N99Q, N179Q, and N870Q) increased the accumulation of DNA damage and downregulated the expression of HR-related genes, demonstrating that CDON N-glycosylation on DNA damage is site-specific and these specific N-glycan sites may regulate HR repair-related transcript abundance of genes. Our data highlight that N-glycosylation of CDON is critical to cardiomyocyte DNA lesion. It may uncover the potential strategies targeting DNA damage pathway in heart disease.

Ling gui shen fu decoction ameliorates cardiac injury in ischemic heart disease rats by regulating ANP32A/HIF2α/HMGB1 signal route

Purpose: To investigate the effect of ling gui shen fu decoction (LGSFD) on cardiac injury and cardiomyocyte apoptosis in rats with ischemic heart disease (IHD), and to elucidate the underlying molecular mechanism. Methods: An IHD rat model was established by performing coronary artery occlusion surgery on the left anterior descending (LAD) of rats. The rats were assigned equally to 5 groups: sham-operated group (sham group), IHD group, IHD + perindopril group, IHD + low- dose LGSFD group (IHD + LGSFD-L group), and IHD + high-dose LGSFD group (IHD+LGSFD-H group). The LGSFD was given via gavage. A hypoxia-induced cardiomyocyte model was established by subjecting H9C2 cells to hypoxia. Then, LGSFD-containing serum or blank serum was used to treat the hypoxic rat cardiomyocytes (H9C2). The severity of cardiac injury and extent of apoptotic changes in cardiomyocytes was determined using hematoxylin-eosin (H&E) staining and TUNEL staining, while immunoblotting was used to measure the protein expressions of ANP32A, p-AKT, AKT, HIF-2α, p-mTOR, mTOR and HMGB1. Results: The cardiac injury of rats in the LGSFD groups was significantly reversed, relative to the IHD group (p < 0.05). Moreover, LGSFD reduced the level of apoptosis in hypoxia- induced H9C2 cells and upregulated the concentrations of ANP32A, p-AKT, HIF-2α and p-mTOR. However, the expression levels of HMGB1 were decreased in the heart tissues of IHD rats and hypoxic H9C2 cells. Silencing of ANP32A with ANP32A siRNA (siANP32A) down- regulated ANP32A, p-AKT, HIF-2α and p-mTOR, but up-regulated apoptosis and expression levels of HMGB1 in hypoxic H9C2 cells. Conclusion: LGSFD ameliorates cardiac injury in IHD rats by inhibiting cardiomyocyte apoptosis via the ANP32A/HIF-2α/HMGB1 axis. Further investigations are recommended into the specific mechanism of LGSFD effect using clinical samples, in order to facilitate its clinical development.

Thyroid Hormone Upregulates Cav1.2 Channels in Cardiac Cells via the Downregulation of the Channels' β4 Subunit.

Thyroid hormone binds to specific nuclear receptors, regulating the expression of target genes, with major effects on cardiac function. Triiodothyronine (T3) increases the expression of key proteins related to calcium homeostasis, such as the sarcoplasmic reticulum calcium ATPase pump, but the detailed mechanism of gene regulation by T3 in cardiac voltage-gated calcium (Cav1.2) channels remains incompletely explored. Furthermore, the effects of T3 on Cav1.2 auxiliary subunits have not been investigated. We conducted quantitative reverse transcriptase polymerase chain reaction, Western blot, and immunofluorescence experiments in H9c2 cells derived from rat ventricular tissue, examining the effects of T3 on the expression of α1c, the principal subunit of Cav1.2 channels, and Cavβ4, an auxiliary Cav1.2 subunit that regulates gene expression. The translocation of phosphorylated cyclic adenosine monophosphate response element-binding protein (pCREB) by T3 was also examined. We found that T3 has opposite effects on these channel proteins, upregulating α1c and downregulating Cavβ4, and that it increases the nuclear translocation of pCREB while decreasing the translocation of Cavβ4. Finally, we found that overexpression of Cavβ4 represses the mRNA expression of α1c, suggesting that T3 upregulates the expression of the α1c subunit in response to a decrease in Cavβ4 subunit expression.

Artemisia argyi mitigates doxorubicin-induced cardiotoxicity by inhibiting mitochondrial dysfunction through the IGF-IIR/Drp1/GATA4 signaling pathway.

Doxorubicin (DOX) is mostly utilized as a wide range of antitumor anthracycline to treat different cancers. The severe antagonistic impacts of DOX on cardiotoxicity constrain its clinical application. Many mechanisms are involved in cardiac toxicity induced by DOX in the human body. Mitochondria is a central part of fatty acid and glucose metabolism. Thus, impaired mitochondrial metabolism can increase heart failure risk, which can play a vital role in cardiomyocyte mitochondrial dysfunction. This study aimed to assess the possible cardioprotective effect of water-extracted Artemisia argyi (AA) against the side effect of DOX in H9c2 cells and whether these protective effects are mediated through IGF-IIR/Drp1/GATA4 signaling pathways. Although several studies proved that AA extract has benefits for various diseases, its cardiac effects have not yet been identified. The H9c2 cells were exposed to 1μM to establish a model of cardiac toxicity. The results revealed that water-extracted AA could block the expression of IGF-IIR/calcineurin signaling pathways induced by DOX. Notably, our results also showed that AA treatment markedly attenuated Akt phosphorylation and cleaved caspase 3, and the nuclear translocation markers NFATC3 and p-GATA4. Using actin staining for hypertrophy, we determined that AA can reduce the effect of mitochondrial reactive oxygen species and cell size. These findings suggest that water-extracted AA could be a suitable candidate for preventing DOX-induced cardiac damage.

Suppressing the expression of steroidogenic acute regulatory protein (StAR) in the myocardium by spironolactone contributes to the improvement of right ventricular remodeling in pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a progressive condition that frequently leads to right ventricular (RV) remodeling. Aldosterone promotes vascular and RV remodeling. The upregulation of steroidogenic acute regulatory protein (StAR) stimulates aldosterone synthesis. However, the expression of StAR in the myocardium under PAH conditions remains unknown. To investigate the expression of StAR in the myocardium and its association with RV remodeling in PAH, utilizing spironolactone as a treatment. A PAH model was created using male Sprague-Dawley rats, which received a subcutaneous injection of Sugen5416 (20 mg/kg) and were exposed to hypoxia (10% O2) for 2 weeks, followed by 2 weeks of normoxia. The animals were then divided into two groups, with one group receiving spironolactone (25 mg/kg/day) for an additional 4 weeks, while the other group did not. H9c2 cells were cultured under hypoxic conditions (37 °C, 1% O2, 5% CO2) with or without spironolactone treatment. In the model rats, RV systolic pressure and the Fulton index, both of which increased upon exposure to Sugen5416 and hypoxia, significantly decreased with spironolactone treatment. In H9c2 cells, hypoxic exposure elevated aldosterone levels, while spironolactone treatment significantly suppressed aldosterone production. Suppression of StAR expression in the myocardium via spironolactone contributes to the improvement of RV remodeling in PAH. Spironolactone may offer a valuable therapeutic strategy for RV remodeling in patients with PAH.

Phloridzin prevents diabetic cardiomyopathy by reducing inflammation and oxidative stress

Oxidative stress and inflammation significantly contribute to the pathogenesis of diabetic cardiomyopathy (DCM). Persistent inflammatory stimuli drive the progression of myocardial fibrosis and impaired cardiac function. Phloridzin (Phl), a natural compound, demonstrates both anti-inflammatory and antioxidant properties. Nevertheless, its therapeutic potential and underlying mechanisms in DCM remain unclear. This study aimed to elucidate the mechanisms through which Phl inhibited myocardial fibrosis and exerted its antioxidative effects. The impact of Phl on DCM was evaluated using a high-fat/high-sugar diet combined with streptozotocin to induce an animal model and an in vitro H9C2 cell model stimulated by high glucose (HG). Untargeted metabolomics identified potential mechanisms underlying myocardial fibrosis. Phl treatment significantly enhanced left ventricular ejection fraction (EF%) and shortening fraction (FS%), while reducing myocardial injury markers, such as lactate dehydrogenase and creatine phosphokinase-MB, and suppressing myocardial collagen fiber accumulation. Simultaneously, Phl attenuated myocardial inflammation via inhibition of MyD88/NF-κB signaling, modulated the Nrf2/GPX4 axis to counter oxidative stress, and mitigated ferroptosis. In vitro, Phl inhibited high glucose-induced myocardial hypertrophy and fibrosis in H9C2 cells, while also repressing NF-κB activation in cardiomyocytes. Metabolomic profiling revealed that Phl ameliorated DCM through modulation of glycerophospholipid metabolic pathways, linking these metabolic shifts to enhanced antioxidant capacity, thereby reflecting its ability to reduce oxidative stress in the myocardium. Collectively, Phl provides cardioprotective effects by alleviating inflammation and oxidative damage.

LncRNA MALAT1 to Enhance Pyroptosis in Viral Myocarditis Through UPF1-Mediated SIRT6 mRNA Decay and Wnt-β-Catenin Signal Pathway.

Viral myocarditis (VMC) is an inflammatory disease of the myocardium caused by cardioviral infection, especially coxsackievirus B3 (CVB3), and is a major contributor to acute heart failure and sudden cardiac death in children and adolescents. LncRNA MALAT1 knockdown reportedly inhibits the differentiation of Th17 cells to attenuate CVB3-induced VMC in mice. Moreover, long non-coding RNAs (lncRNAs) interact with RNA-binding proteins (RBPs) to regulate UPF1-mediated mRNA decay. However, it remains unclear whether MALAT1 can bind to UPF1 to mediate the mRNA decay of its target genes in VMC. Herein, we aimed to explore the effect of lncRNA MALAT1 on UPF1-mediated SIRT6 mRNA decay in VMC using in vivo and in vitro experiments. CVB3-infected BABL/C mice were used as VMC models, and MALAT1 interfering adenovirus was injected to achieve MALAT1 knockdown. The heart function of the VMC mice was assessed using echocardiography. Pathological changes in myocardial tissues were assessed after hematoxylin-eosin staining. Myocardial injury and inflammation were evaluated by measuring creatine kinase isoenzyme B, cardiac troponin T, interleukin (IL)-1β, and IL-18. TUNEL staining was performed to assess apoptosis in myocardial tissues. In vitro experiments were performed using H9c2 cells after transfection and CVB3 infection. The lactic dehydrogenase release, caspase-1 activity, and IL-1β and IL-18 levels in the cellular supernatant were detected. Western blotting was performed to determine the expression of pyroptosis-related proteins (GSDMD-N, NLRP3, ASC, and Cleaved-Caspase-1) and Wnt/β-catenin signal pathway-related proteins (Wnt1, β-catenin, and p-GSK-3β). RNA immunoprecipitation and RNA stability assays assessed the relationship between MALAT1, UPF1, and SIRT6. CVB3-infected mice and H9c2 cells exhibited elevated MALAT1 and reduced SIRT6 expression. MALAT1 knockdown or SIRT6 overexpression suppressed inflammation and pyroptosis and inhibited the activation of the Wnt/β-catenin signal pathway in myocardial tissues and cells. MALAT1 enhanced the enrichment of SIRT6 mRNA by UPF1 and disturbed the stability of SIRT6 mRNA to promote the development of VMC. MALAT1 can bind UPF1 to mediate SIRT6 mRNA decay and activate the Wnt/β-catenin signal pathway in VMC.

Salidroside rescues hypoxic cardiomyocytes by regulating the EGLN1/HIF‑1α pathway.

Myocardial infarction is characterized by oxygen deficiency caused by arterial flow restriction. Salidroside (SAL) protects against myocardial damage via antioxidant production and inhibition of apoptosis. The present study aimed to investigate potential rescue mechanism of SAL on hypoxic cardiomyocytes. H9C2 cardiomyocytes were divided into normoxia, hypoxia and hypoxia + SAL groups. The inhibitory rate of hypoxia and the optimal concentration and rescue effect of SAL were determined using Cell Counting Kit-8 assay and flow cytometry. Ca2+ concentration following hypoxia treatment and SAL intervention were detected by Fluo-4/acetoxymethyl. Tandem mass tag (TMT) proteomics was used to analyze the differential expression of hypoxia-associated proteins among the three groups. SAL exerted a protective effect on hypoxia-injured cardiomyocytes by enhancing aerobic metabolism during hypoxia and rescuing cardiomyocytes from hypoxic damage. SAL promoted cell proliferation, decreased apoptosis and increased Ca2+ levels in cell membranes of hypoxic cardiomyocytes. TMT proteomics results showed that the expression levels of intracellular hypoxia inducible factor-1 (HIF)-1α and Egl-9 family HIF 1 (EGLN1) in H9C2 cells were elevated under hypoxic conditions. However, SAL significantly decreased expression levels of HIF-1α and EGLN1. SAL inhibited mitochondrial calcium overload in hypoxic cardiomyocytes and attenuated expression of hypoxia-associated factors. SAL exerted its rescue effect on hypoxic cardiomyocytes through the EGLN1/HIF-1α pathway, thereby suppressing cardiomyocyte apoptosis, improving mitochondrial energy metabolism efficiency and rescuing cardiomyocytes from hypoxic injury.

Propofol Ameliorates Sepsis-Induced Myocardial Dysfunction via Anti-Apoptotic, Anti-Oxidative Properties, and mTOR Signaling.

Sepsis often leads to cardiomyopathy, contributing to increased mortality rates. 2,6-Diisopropylphenol (propofol), an anesthetic, has demonstrated efficacy in protecting cardiomyocytes from cell death caused by hypoxia and reoxygenation. This study examined the effects of propofol on sepsis-associated myocardial dysfunction and explored the underlying mechanism of action. Mice and rat cardiomyocytes (H9C2 cell line) were used to establish a sepsis-induced myocardial dysfunction model. Lipopolysaccharides (LPS)-treated mice and H9C2 cells were treated with propofol, with rapamycin used for mechanistic studies in H9C2 cells. Cardiac function was evaluated by echocardiographic measurements. Heart tissues were stained with hematoxylin and eosin, and heart weight/body weight ratio along with the levels of cardiac biomarkers were measured using Enzyme Linked Immunosorbent Assay (ELISA). Activation of the mammalian target of rapamycin (mTOR) pathway was assessed by western blotting. Apoptosis in heart tissues and H9C2 cells was evaluated using Terminal deoxynucleotidyl transferase (TdT) dUTP nick end labeling (TUNEL) assay, and cell viability was quantified using Cell Counting Kit (CCK)-8 assay. Oxidative stress in H9C2 cells was assessed by measuring reactive oxygen species (ROS) levels through immunofluorescence staining and malondialdehyde (MDA) and superoxide dismutase (SOD) levels using ELISA. Propofol reversed LPS-induced myocardial changes and cardiac dysfunction (p < 0.05). In mouse tissues and H9C2 cells, propofol reversed LPS-induced mTOR pathway inhibition and apoptosis (p < 0.001). Moreover, propofol alleviated oxidative stress in LPS-treated cells. The activation of the mTOR pathway by propofol, along with its inhibitory effects on oxidative stress and apoptosis in cardiomyocytes, was negated by rapamycin (p < 0.001). Propofol ameliorates sepsis-induced myocardial dysfunction triggered by LPS through the mTOR pathway, thereby promoting antioxidative stress and reducing cell apoptosis.

Quercetin Promotes the Repair of Mitochondrial Function in H9c2 Cells Through the miR-92a-3p/Mfn1 Axis.

Cardiocerebrovascular disease is a severe threat to human health. Quercetin has a wide range of pharmacological effects such as antitumor and antioxidant. In this study, we aimed to determine how quercetin regulates mitochondrial function in H9c2 cells. An H9c2 cell oxygen glucose deprivation/reoxygenation (OGD/R) model was constructed. The expression of miR-92a-3p and mitofusin 1 (Mfn1) mRNA in the cells was detected using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Changes in the mitochondrial membrane potential of cells were examined by JC-1 staining. ATP production in the cells was detected using a biochemical assay. Mitochondrial morphological changes were observed using transmission electron microscopy. Detection of miR-92a-3p binding to Mfn1 was done using dual luciferase. Western blotting was used to detect the protein expression of Mfn1 in the cells. miR-92a-3p is essential in regulating cell viability, apoptosis, and tumor cell metastasis. OGD/R induced miR-92a-3p expression, decreased mitochondrial membrane potential and mitochondrial ATP production, and increased mitochondrial damage. Mitochondria are the most critical site for ATP production. Continued opening of the mitochondrial permeability transition pore results in an abnormal mitochondrial transmembrane potential. Both quercetin and inhibition of miR-29a-3p were able to downregulate miR-29a-3p levels, increase cell viability, mitochondrial membrane potential, and ATP levels, and improve mitochondrial damage morphology. Furthermore, we found that downregulation of miR-29a-3p upregulated the protein expression of Mfn1 in cells. Additionally, miR-92a-3p was found to bind to Mfn1 in a luciferase assay. miR- 29a-3p overexpression significantly inhibited the protein expression level of Mfn1. Quercetin treatment partially reversed the effects of miR-29a-3p overexpression in H9c2 cells. Quercetin promoted the recovery of mitochondrial damage in H9c2 cells through the miR-92a-3p/Mfn1 axis.

Quercetin Inhibits Cardiomyocyte Apoptosis via Sirt3/SOD2/Mitochondrial Reactive Oxygen Species during Myocardial Ischemia–Reperfusion Injury

BackgroundMyocardial ischemia/reperfusion injury (MI/RI) can lead to impaired cardiac function. Quercetin (Que) has a positive effect and improves MI/RI. Sirtuin-3 (Sirt3) is a deacetylase that ameliorates oxidative stress and is associated with MI/RI. This study aimed to investigate the molecular mechanism by which Que protects cardiac function against MI/RI through the Sirt3 signaling pathway. MethodsWe conducted experiments by constructing hypoxia/reoxygenation (H/R) cardiomyocytes and MI/RI rat models. H9C2 cells were transfected with siRNA-Sirt3. Cardiomyocyte apoptosis was examined by TUNEL and Western blotting. The oxidative stress index was also determined. Mitochondrial reactive oxygen species (ROS) activity assays, ATP assays and mitochondrial membrane potential assays were performed. Evans Blue/TTC staining was used to examine surviving myocardial tissue. ResultsIn the constructed H/R cells and MI/RI animal models, it was found that myocardial cell apoptosis increased (Bcl-2 expression was downregulated; Bax and cleaved caspase-3/8/9 expression were upregulated). In addition, oxidative stress levels increased (MDA levels increased; SOD, CAT, GSH-Px levels decreased), myocardial tissue was damaged (LDH, CK content increased), Sirt3 expression was downregulated, acetylation levels of superoxide dismutase 2 (SOD2) increased (AC-SOD2), and mitochondrial ROS increased. Que treatment alleviated the effects of MI/RI on cardiomyocytes and rats. Sirt3 expression and activity were upregulated, SOD2 acetylation was decreased, and mitochondrial ROS production was reduced by Que treatment. After Sirt3 was knocked down, we found that AC-SOD2 expression was upregulated and mitochondrial ROS were increased in H/R cardiomyocytes, further increased the degree of injury, while Que treatment attenuated the effect of Sirt3 knockdown on H/R cardiomyocytes. ConclusionQue inhibits cardiomyocyte apoptosis, reduces oxidative stress levels, protects mitochondrial function and prevents the impairment of cardiac function during MI/RI via the Sirt3/SOD2/mitochondrial ROS pathway.

Apelin-13's Actions in Controlling Hypertension-Related Cardiac Hypertrophy and the Expressions of Inflammatory Cytokines.

As a key molecule for improving cardiovascular diseases, Apelin-13 was surveyed in this work to explain its actions in controlling inflammation, pyroptosis, and myocardial hypertrophy. First, mouse models with myocardial hypertrophy were established. Then, assessments were made on the pathological variation in the heart of mouse, on the cardiac functions, as well as on the expressions of cardiac hypertrophy markers (β-MHC, ANP, and BNP), inflammatory factors (TNF-α, COX2, IL-6, ICAM-1, and VCAM-1), myocardial cell pyroptosis markers (NLRP3, ASC, c-caspase-1, and GSDMD-N), and Hippo pathway proteins (p-YAP, YAP, LATS1, and p-LATS1) by HE staining, echocardiography scanning, and western blot tests separately. The expressions of such inflammatory factors as in myocardial tissue were acquired by ELISA. After inducing the phenotype of H9c2 cell hypertrophy by noradrenaline, we used CCK-8 kits to know about the activity of H9c2 cells treated with Apelin-13, and performed ɑ-actinin staining to measure the changes in volumes of such cells. As unraveled through this work, Apelin-13 refrained the activation of the Hippo pathway, which in turn attenuated the hypertrophy, inflammation, and pyroptosis of myocardial tissue and H9c2 cells. Hence, Apelin-13 can be considered as a target for hypertension treatment.

Po-Ge-Jiu-Xin decoction alleviate sepsis-induced cardiomyopathy via regulating phosphatase and tensin homolog-induced putative kinase 1 /parkin-mediated mitophagy

Ethnopharmacological relevanceSepsis is a life-threatening systemic syndrome usually accompanied by myocardial dysfunction. Po-Ge-Jiu-Xin decoction (PGJXD), a traditional Chinese prescription medicine, has been used clinically to treat cardiovascular disease including heart failure, sepsis-induced cardiomyopathy (SIC) and even septic shock. Previous clinical studies suggested PGJXD has shown promising results in improving cardiac function and treating heart failure in sepsis. However, more research is needed to elucidate the mechanisms underlying PGJXD's therapeutic effects in sepsis-induced cardiomyopathy. Materials and MethodsInitially, we identified the major compounds of PGJXD through ultra-performance liquid chromatography-mass spectrometry technology analysis. We established in a SIC rat model using cecal ligation and puncture(CLP) and treated by PGJXD and levosimendan. We evaluated pathological damage by hematoxylin and eosin staining and measured serum myocardial injury biomarkers. Myocardial apoptosis was detected by Tunel staining and quantifying specific biomarker protein levels. Subsequently, we evaluated myocardium mitochondrial quality using Transmission electron microscope (TEM), antioxidant stress indexes and tissue adenosine triphosphate(ATP) content. We detected the expression of phosphatase and tensin homolog (PTEN)-induced putative kinase 1 (PINK1), parkin, LC3, and p62 using Western blotting and Quantitative real time polymerase chain reaction(qRT-PCR). (Lipopolysaccharides, LPS)-induced H9c2 cell model was established to further explore the mechanism of PGJXD on SIC. In addition to measuring cell viability, we measured mitochondrial membrane potential using JC-1 staining. Additionally, Parkin-siRNA transfected into H9c2 cells to validate whether PGJXD conducted protective effects against SIC through PINK1/Parkin-mediated mitophagy. ResultsIt has been demonstrated that PGJXD reduced mortality in septic rat, contributed to ameliorating myocardium injury, suppressed inflammatory response and ameliorated the myocardial apoptosis. PGJXD could also alleviate mitochondrial structural abnormality, mitigated oxidative stress injury and promoted energy synthesis in CLP models. Western blotting and qRT-PCR have further confirmed that PGJXD can activate PINK1/parkin pathway-mediated mitophagy, resulting in preserving mitochondrial quality in the myocardium. Furthermore, Parkin siRNA partially reversed the beneficial effect of PGJXD on mitochondrial fission/fusion and mitophagy in vitro. Therefore, the cardioprotective effect of PGJXD is achieved by inducing PINK1/Parkin-mediated mitophagy in maintaining mitochondrial homeostasis. ConclusionsThese results suggest that the potential therapeutic effect of PGJXD on cardiac dysfunction during sepsis and support its mechanism of targeted induction of PINK1-Parkin-mediated mitophagy.

Ablation of CCDC8 provides cardioprotection against cardiomyocyte apoptosis via TNF signaling pathway in myocardial ischemia reperfusion injury

AimsMyocardial ischemia-reperfusion (I/R) injury induces significant apoptosis and reactive oxygen species (ROS) accumulation in cardiomyocytes. Coiled-coil domain-containing 8 (CCDC8), recently identified as an interacting protein of p53, acts as a cofactor in p53-mediated apoptosis. However, its role in myocardial I/R injury remains unclear. Materials and methodsWe first assessed CCDC8 levels in patients with left ventricular failure (LVF) and in both in vivo and in vitro models of myocardial I/R injury. Next, we used adenovirus 9 (AAV9) to overexpress CCDC8 and small interfering RNA (siRNA) to investigate the role of CCDC8 in myocardial I/R injury. mRNA sequencing and KEGG pathway analysis were performed to identify CCDC8-regulated genes. In vitro experiments were conducted to examine the effects of CCDC8 silencing on TNF-α-induced apoptosis. Key findingsCCDC8 expression was elevated in the left ventricle of LVF patients and in the cardiomyocytes of mice subjected to myocardial I/R injury. Overexpression of CCDC8 in cardiomyocytes via AAV9 exacerbated cardiac dysfunction caused by myocardial I/R injury, while silencing CCDC8 suppressed apoptosis and ROS production in H9c2 cells under hypoxia-reoxygenation (H/R) conditions. mRNA sequencing and KEGG analysis indicated that CCDC8 regulates genes related to cardiac contractility and the TNF signaling pathway. Additionally, CCDC8 silencing reversed TNF-α-induced cardiomyocyte apoptosis in vitro. SignificanceThis study identifies CCDC8 as a key mediator of cardiomyocyte apoptosis via the TNF signaling pathway in myocardial I/R injury. These findings suggest that targeting CCDC8 could be a potential therapeutic strategy for mitigating cardiac dysfunction in myocardial I/R injury.

WITHDRAWN: Shenmai Injection Exerts the Cardioprotective Effects by Modulating Autophagy-apoptosis via Beclin-1

Background and aimDespite the excellent efficacy of anthracyclines, their clinical application is subject to cardiotoxicity. Studies have shown that Shenmai Injection(SMI) alleviated anthracycline-induced myocardial injury, however, the exact mechanism has not been clarified. Experimental procedureEach intervention was explored by detecting the viability of cardiomyocytes, LDH leakage rate, and CK levels. Finally, the effects of each intervention on autophagy-apoptosis and Beclin-1 were observed by using mCherry-EGFP-LC3B double fluorescence method, Annexin V/propidium iodide (PI), and protein immunoblotting method to explain the mechanism of Shenmai Injection. Key resultsThe viability of H9c2 cells in the model group decreased, accompanied by elevated LDH leakage rate and CK levels after doxorubicin intervention (P<0.01 or P<0.05). In contrast, SMI reversed above situation (P<0.01 or P<0.05). Besides, autophagy and apoptosis up-regulated in the model group (P<0.01), accompanied by upregulated Beclin-1, LC3-II, LC3-II/LC3-I, apoptosis effector proteins Cleaved-Caspase-9, Cleaved-Caspase-9/Caspase-9, Cleaved-Caspase-3, Cleaved-Caspase-3/Caspase-3 expressions and the downregulation of p62 protein, anti-apoptotic protein Bcl2 expressions (P<0.01 or P<0.05). Nonetheless, autophagy and apoptosis were decreased with the help of SMI (P<0.01 or P<0.05). ConclusionSMI alleviated autophagy and apoptosis of damaged cardiomyocytes by regulating Beclin-1.

Fibroblast Growth Factor 21 Suppressed Neutrophil Extracellular Traps Induced by Myocardial Ischemia/Reperfusion Injury via Adenosine Monophosphate-Activated Protein Kinase.

Previous investigations have established the anti-inflammatory properties of fibroblast growth factor 21 (FGF21). However, the specific mechanism through which FGF21 mitigates myocardial ischemia/reperfusion (I/R) injury by inhibiting neutrophil extracellular traps (NETs) remains unclear. A mice model of myocardial I/R injury was induced, and myocardial tissue was stained with immunofluorescence to assess NETs. Serum NETs levels were quantified using a PicoGreen kit. In addition, the expression levels of adenosine monophosphate (AMP)-activated protein kinase (AMPK) and FGF21 were evaluated by Wes fully automated protein blotting quantitative analysis system. Moreover, a hypoxia/reoxygenation (H/R) model was established using AMPK inhibitor and agonist pretreated H9c2 cells to further explore the relationship between FGF21 and AMPK. Compared with the control group, serum NETs levels were significantly higher in I/R mice, and a large number of NETs were formed in myocardial tissues (97.63 ± 11.45 vs. 69.65 ± 3.33, P < 0.05). However, NETs levels were reversed in FGF21 pretreated mice (P < 0.05). Further studies showed that FGF21 enhanced AMPK expression, which was significantly increased after inhibition of AMPK and decreased after promotion of AMPK (P < 0.05). FGF21 may exert cardioprotective effects by inhibiting I/R injury-induced NETs via AMPK.

Inhibiting glycosphingolipids alleviates cardiac hypertrophy by reducing reactive oxygen species and restoring autophagic homeostasis.

Cardiac hypertrophy is a compensatory stress response produced by a variety of factors, and pathologic hypertrophy can lead to irreversible, severe cardiac disease. Glycosphingolipids (GSLs) are vital constituents of cells, and changes in their content and composition are important factors causing mitochondrial dysfunction in diabetic cardiomyopathy; however, the relationship between GSLs expression and cardiac hypertrophy and specific mechanisms associated with it are not clear. Here, using male C57BL/6 mice, we performed aortic arch reduction surgery to establish an animal model of pressure overload cardiac hypertrophy. In addition, phenylephrine was used in vitro to induce H9c2 cells and neonatal rat left ventricular myocytes (NRVMs) to establish a cellular hypertrophy model. Mass spectrometry revealed that the composition of GSLs was altered in pressure overload-induced hypertrophied mouse hearts and in stimulated hypertrophied cardiomyocyte cell lines. Specifically, in both cases, the proportion of endogenous lactosylceramide (LacCer) was significantly higher than in controls. Inhibition of GSL synthesis with Genz-123346 in NRVMs reduced cell hypertrophy, as well as fibrosis and apoptosis. By Western blotting, we detected decreased intracellular expression of Sirt3 and elevated phosphorylation of JNK after phenylephrine stimulation, but this was reversed in cells pretreated with Genz-123346. Additionally, increased protein expression of FoxO3a and Parkin, along with a decreased LC3-II/I protein ratio in phenylephrine-stimulated cells (compared with unstimulated cells), indicated that the mitochondrial autophagy process was disrupted; again, pretreatment with Genz-123346 reversed that. Our results revealed that changes in GSLs in cardiomyocytes, especially an increase of LacCer, may be a factor causing cellular hypertrophy, which can be alleviated by inhibition of GSLs synthesis. A possible mechanism is that GSLs inhibition increases the expression of Sirt3 protein, scavenges intracellular reactive oxygen species, and restores mitochondrial autophagy homeostasis, thereby lessening cardiomyocyte hypertrophy. In all, these results provide a new perspective for developing drugs for cardiac hypertrophy.