Cardiomyocyte Apoptosis Research Articles

ACE2 alleviates sepsis-induced cardiomyopathy through inhibiting M1 macrophage via NF-κB/STAT1 signals

Angiotensin-converting enzyme 2 (ACE2), a crucial element of the renin-angiotensin system (RAS), metabolizes angiotensin II into Ang (1–7), which then combines with the Mas receptor (MasR) to fulfill its protective role in various diseases. Nevertheless, the involvement of ACE2 in sepsis-induced cardiomyopathy (SIC) is still unexplored. In this study, our results revealed that CLP surgery dramatically impaired cardiac function accompanied with disruption of the balance between ACE2-Ang (1–7) and ACE-Ang II axis in septic heart tissues. Moreover, ACE2 knockin markedly alleviated sepsis induced RAS disorder, cardiac dysfunction and improved survival rate in mice, while ACE2 knockout significantly exacerbates these outcomes. Adoptive transfer of bone marrow cells and in vitro experiments showed the positive role of myeloid ACE2 by mitigating oxidative stress, inflammatory response, macrophage polarization and cardiomyocyte apoptosis by blocking NF-κB and STAT1 signals. However, the beneficial impacts were nullified by MasR antagonist A779. Collectively, these findings showed that ACE2 alleviated SIC by inhibiting M1 macrophage via activating the Ang (1–7)-MasR axis, highlight that ACE2 might be a promising target for the management of sepsis and SIC patients.

GQ262 Attenuates Pathological Cardiac Remodeling by Downregulating the Akt/mTOR Signaling Pathway.

Cardiac remodeling, a critical process that can lead to heart failure, is primarily characterized by cardiac hypertrophy. Studies have shown that transgenic mice with Gαq receptor blockade exhibit reduced hypertrophy under induced pressure overload. GQ262, a novel Gαq/11 inhibitor, has demonstrated good biocompatibility and specific inhibitory effects on Gαq/11 compared to other inhibitors. However, its role in cardiac remodeling remains unclear. This study aims to explore the anti-cardiac remodeling effects and mechanisms of GQ262 both in vitro and in vivo, providing data and theoretical support for its potential use in treating cardiac remodeling diseases. Cardiac hypertrophy was induced in mice via transverse aortic constriction (TAC) for 4 weeks and in H9C2 cells through phenylephrine (PE) induction, confirmed with WGA and H&E staining. We found that GQ262 improved cardiac function, inhibited the protein and mRNA expression of hypertrophy markers, and reduced the levels of apoptosis and fibrosis. Furthermore, GQ262 inhibited the Akt/mTOR signaling pathway activation induced by TAC or PE, with its therapeutic effects disappearing upon the addition of the Akt inhibitor ARQ092. These findings reveal that GQ262 inhibits cardiomyocyte hypertrophy and apoptosis through the Akt/mTOR signaling pathway, thereby reducing fibrosis levels and mitigating cardiac remodeling.

LncRNA Pvt1 aggravates cardiomyocyte apoptosis via the microRNA-216/Ccnd3 axis

ObjectiveOur study aims to evaluate the role of long non-coding RNA variant translocation gene Pvt1 in cardiomyocyte apoptosis, as well as the potential targets and mechanisms involved in Pvt1-miRNA-mRNA axis. Methods1.Pvt1 knockdown in cells by transfection with small interfering RNA (si-Pvt1), HL-1 cells were randomly divided into control group, hypoxia group, hypoxia + negative control group and hypoxia + si-Pvt1 group. Apoptosis-related genes expression was detected by Western blot assay, RT-qPCR and Flow cytometry assay. 2.Pvt1 knockdown model (sh-Pvt1) was established by injecting adeno-associated virus (AAV) vector shRNA-Pvt1 into the caudal vein 7 days before myocardial infarction, and echocardiography was used to measure cardiac function 7 days after myocardial infarction induced by ligation of the left anterior descending branch. HE staining was used to evaluate the pathological injury of mouse heart tissue, and the apoptotic protein expression was detected by Western blot. 3.lncRNA-related microRNAs were predicted by bioinformatics tools and further verified by dual luciferase experiment. Western blot analysis was used to identify the expression of apoptotic genes following the simultaneous transfection of si-Pvt1 and miR-216 mimics. Genes differentially expressed in hypoxia + si-NC and hypoxia + si-Pvt1 groups were identified by RNA sequencing. These genes were then compared with the target genes of miR-216 predicted by bioinformatics tools. The gene of interest Ccnd3 was excluded from the analysis. Western blot analysis was used to assess the expression of Apoptosis-related proteins in HL-1 cells co-transfected with miR-216 mimics and overexpressed Ccnd3. Results1. Pvt1 was highly expressed in HL-1 induced by hypoxia, and Pvt1 knockdown can reduce cell apoptosis in hypoxia cells. 2. MI causes myocardial injury in mice, and inhibition of Pvt 11 can improve the cardiac function of mice with myocardial infarction, prevent some inflammatory cell infiltration, and reduce myocardial cell apoptosis. 3. Pvt1 acts as a sponge for miR-216 and promotes the expression of Ccnd3. ConclusionPvt1 may promote myocardial infarct-induced apoptosis through the miR-216/Ccnd3 axis.

Ablation of mitophagy receptor FUNDC1 accentuates septic cardiomyopathy through ACSL4-dependent regulation of ferroptosis and mitochondrial integrity

Sepsis evokes compromised myocardial function prompting heart failure albeit target therapy remains dismal. Our study examined the possible role of mitophagy receptor FUNDC1 in septic cardiomyopathy. A sepsis model was established using cecal ligation and puncture (CLP) in FUNDC1 knockout (FUNDC1−/−) and WT mice prior to the evaluation of cardiac morphology, echocardiographic and cardiomyocyte contractile, oxidative stress, apoptosis, necroptosis, and ferroptosis. RNAseq analysis depicted discrepant patterns in mitophagy, oxidative stress and ferroptosis between CLP-challenged and control murine hearts. Septic patients displayed cardiac injury alongside low plasma FUNDC1 and iron levels. CLP evoked interstitial fibrosis, cardiac dysfunction (lowered ejection fraction, fractional shortening, shortening/relengthening velocity, peak shortening and electrically-stimulated intracellular Ca2+ rise, alongside increased LV end systolic diameter and relengthening duration), O2− buildup, apoptosis, necroptosis, and ferroptosis (downregulated GPX4 and SLC7A11), the responses of which were accentuated by FUNDC1 ablation. In particular, levels of lipid peroxidation enzyme acyl-CoA synthetase long-chain family member 4 (ACSL4) were upregulated following CLP procedure, with a more pronounced response in FUNDC1−/− mice. Co-immunoprecipitation and interaction interface revealed an evident interaction between FUNDC1 and ACSL4. In vitro studies revealed that the endotoxin lipopolysaccharide provoked cardiomyocyte contractile and lipid peroxidation anomalies, the responses were reversed by the mitophagy inducer oleanolic acid, inhibition of ACSL4 and ferroptosis. These findings favor a role for FUNDC1-ACSL4-ferroptosis cascade in septic cardiomyopathy.

Halofuginone ameliorates the susceptibility to atrial fibrillation by activating the PI3K/Akt signaling pathway.

Atrial fibrillation (AF) is the most common cardiac arrhythmia in clinical practice. Halofuginone (HF) exerts beneficial effects on organ fibrosis, periodontitis, and cancer. However, the effect of HF against AF remains unknown. During the induction of AF, the rats were intragastrically administered HF (5mg/kg and 10mg/kg) daily for 7 consecutive days. Cardiac function was evaluated through echocardiographic analysis. The presence of pathological changes and interstitial fibrosis in the left atrial tissues were investigated. Intracellular Ca2+ homeostasis and mitochondrial function in atrial tissues were evaluated. The activation of the PI3K/Akt signaling pathway was examined, and an allosteric Akt inhibitor, MK-2206, was applied to confirm the involvement of the PI3K/Akt signaling pathway in the protection against AF by HF. The administration of HF resulted in a prolongation of the atrial effective refractory period (AERP), a reduction in both the duration and inducibility of AF, and a decrease in atrial weight, heart weight, atrial weight/body weight ratio, and heart weight/body weight ratio in rats with AF. In addition, the administration of HF resulted in a reduction in left atrial diameter (LAD) and an increase in left ventricular internal diameter diastolic (LVIDd), ejection fraction (EF), and fractional shortening (FS), while having no effect on left ventricular internal diameter systolic (LVIDs). The pathological changes and cardiac fibrosis observed in rats with AF were mitigated by HF. Moreover, HF enhanced mitochondrial function, suppressed cardiomyocyte apoptosis, and activated the PI3K/Akt pathway in AF rats. Furthermore, the protective effect against AF was also observed in an in vitro model. The effects of HF on fibrosis markers, intracellular Ca2+ homeostasis, mitochondrial function, and cardiac apoptosis were blocked by MK-2206. HF alleviated the susceptibility to AF in vivo and in vitro via the activation of the PI3K/Akt signaling pathway.

Exendin-4 exhibits cardioprotective effects against high glucose-induced mitochondrial abnormalities: Potential role of GLP-1 receptor and mTOR signaling

Mitochondrial dysfunction is associated with hyperglycemic conditions and insulin resistance leading to cellular damage and apoptosis of cardiomyocytes in diabetic cardiomyopathy. The dysregulation of glucagon-like peptide-1 (GLP-1) receptor and mammalian target of rapamycin (mTOR) is linked to cardiomyopathies and myocardial dysfunctions mediated by hyperglycemia. However, the involvements of mTOR for GLP-1 receptor-mediated cardioprotection against high glucose (HG)-induced mitochondrial disturbances are not clearly identified. The present study demonstrated that HG-induced cellular stress and mitochondrial damage resulted in impaired ATP production and oxidative defense markers such as catalase and SOD2, along with a reduction in survival markers such as Bcl-2 and p-Akt, while an increased expression of pro-apoptotic marker Bax was observed in H9c2 cardiomyoblasts. In addition, the autophagic marker LC3-II was considerably reduced, together with the disruption of autophagy regulators (p-mTOR and p-AMPKα) under the hyperglycemic state. Furthermore, there was a dysregulated expression of several indicators related to mitochondrial homeostasis, including MFN2, p-DRP1, FIS1, MCU, UCP3, and Parkin. Remarkably, treatment with either exendin-4 (GLP-1 receptor agonist) or rapamycin (mTOR inhibitor) significantly inhibited HG-induced mitochondrial damage while co-treatment of exendin-4 and rapamycin completely reversed all mitochondrial abnormalities. Antagonism of GLP-1 receptors using exendin-(9–39) abolished these cardioprotective effects of exendin-4 and rapamycin under HG conditions. In addition, exendin-4 attenuated HG-induced phosphorylation of mTOR, and this inhibitory effect was antagonized by exendin-(9–39), indicating the regulation of mTOR by GLP-1 receptor. Therefore, improvement of mitochondrial dysfunction by stimulating the GLP-1 receptor/AMPK/Akt pathway and inhibiting mTOR signaling could ameliorate cardiac abnormalities caused by hyperglycemic conditions.

Surface engineering enhances the therapeutic potential of systemically delivered extracellular vesicles following acute myocardial infarction.

The objective of the study was to assess the therapeutic efficacy of targeting remote zone cardiomyocytes with cardiosphere-derived cell (CDC) extracellular vesicles (EVs) delivered via intramyocardial and intravenous routes following acute myocardial infarction (MI). Cardiomyocyte (CM) cell death plays a significant role in left ventricular (LV) remodeling and cardiac dysfunction following MI. While EVs secreted by CDCs have shown efficacy in promoting cardiac repair in preclinical models of MI, their translational potential is limited by their biodistribution and requirement for intramyocardial delivery. We hypothesized that engineering the surface of EVs to target cardiomyocytes would enhance their therapeutic efficacy following systemic delivery in a model of acute MI. CDC-derived EVs were engineered to express a CM-specific binding peptide (CMP) on their surface and characterized for size, morphology, and protein expression. Mice with acute MI underwent both intramyocardial and intravenous delivery of EVs, CMP-EVs and placebo in a double-blind study. LVEF was assessed by echo at 2- and 28-days post-MI and tissue samples processed for assessment of EV biodistribution and histological endpoints. CMP-EVs demonstrated superior cardiac targeting and retention when compared with unmodified EVs 24 h post-MI. Mice treated with IV delivered CMP-EVs demonstrated a significant improvement in LVEF and a significant reduction in remote zone cardiomyocyte apoptosis when compared with IV delivered non-targeted EVs at 28-day post-MI. Systemic administration of CMP-EVs improved cardiac function and reduced remote zone cardiomyocyte apoptosis compared with IV-administered unmodified EVs, demonstrating a strategy to optimize therapeutic EV delivery post-MI.

Borneol promotes berberine-induced cardioprotection in a rat model of myocardial ischemia/reperfusion injury via inhibiting P-glycoprotein expression

Berberine is reported to protect the heart against ischemia/reperfusion (I/R) injury, although efficacy is limited by low bioavailability. This study aims to determine whether borneol, a classic guiding drug, can enhance the cardioprotection induced by berberine and to clarify the underlying mechanisms involving P-glycoprotein (P-gp) in the heart. Adult male Sprague Dawley rats were gavaged with berberine (200 mg/kg) with or without borneol (100 mg/kg) for 7 consecutive days. A rat model of myocardial I/R injury was established by 30 min left coronary artery occlusion followed with 120 min reperfusion. The arrhythmia score, cardiac enzyme content, and myocardial infarct size were determined following reperfusion. Heart tissues were collected for Western blot and immunofluorescence analyses to measure the protein expression levels of Bcl-2, Bax, and P-gp. The results showed that administration of berberine protected the heart against I/R injury, as demonstrated by lower arrhythmia scores, serum cTnI contents, myocardial infarct size, and cardiomyocytes apoptosis. Moreover, borneol substantially enhanced the cardioprotective effects of berberine. Western blot and immunofluorescence analyses showed that both berberine and I/R injury did not alter P-gp expression in heart. In contrast, borneol combined with berberine significantly reduced P-gp levels by 43.4% (P = 0.0240). Interestingly, treatment with borneol alone decreased P-gp levels, but did not protect against myocardial I/R injury. These findings suggest that borneol, as an adjuvant drug, improved the cardioprotective effects of berberine by inhibiting P-gp expression in heart. Borneol combined with berberine administration provides a new strategy to protect the heart against I/R injury.

Sepsis induces the cardiomyocyte apoptosis and cardiac dysfunction through activation of YAP1/Serpine1/caspase-3 pathway.

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. Bioinformatics analysis was used to identify differentially expressed genes in septic mice heart and validate key genes and pathways. The correlation of protein-protein and protein-pathway was analyzed. Sequentially, the cecal ligament and puncture (CLP) was used to induce septic mice, followed by Serpine1 inhibitor treatment. Finally, the regulatory relationship of Yes-associated protein1 (YAP1), Serpine1, and caspase-3 was verified in LPS-exposed mouse cardiomyocytes. Bioinformatic analysis found that Serpine1 expression is decreased in septic mice heart tissue and closely related to the HIPPO signaling pathway, while YAP1 is negatively correlated with apoptosis. In vivo, CLP induced a reduction of survival rate, cardiac dysfunction, and an increase in Serpine1 and Cleaved Caspase-3 expression, which could be reversed by a Serpine1 inhibitor. In vitro, LPS induced the mouse cardiomyocytes apoptosis, which could be reversed by Serpine1 inhibitor. Silencing YAP1 and Serpine1 reversed the LPS-induced increase in Serpine1 and Cleaved Caspase-3 expression, but silencing Serpine1 did not affect the LPS-induced YAP1 expression. Sepsis induced mouse cardiomyocytes apoptosis and cardiac dysfunction through activation of YAP1/Serpine1/caspase-3 pathway.

Matairesinol blunts adverse cardiac remodeling and heart failure induced by pressure overload by regulating Prdx1 and PI3K/AKT/FOXO1 signaling

BackgroundPathological cardiac remodeling is a critical process leading to heart failure, characterized primarily by inflammation and apoptosis. Matairesinol (Mat), a key chemical component of Podocarpus macrophyllus resin, exhibits a wide range of pharmacological activities, including anti-hydatid, antioxidant, antitumor, and anti-inflammatory effects. PurposeThis study aims to investigate whether Matairesinol alleviate cardiac hypertrophy and remodeling caused by pressure overload and to elucidate its mechanism of action. MethodsAn in vitro pressure loading model was established using neonatal rat cardiomyocytes treated with angiotensin Ⅱ, while an in vivo model was created using C57 mice subjected to transverse aortic constriction (TAC). To activate the PI3K/Akt/FoxO1 pathway, Ys-49 was employed. Moreover, small interfering RNA (siRNA) and short hairpin RNA (shRNA) were utilized to silence Prdx1 expression both in vitro and in vivo. Various techniques, including echocardiography, wheat germ agglutinin (WGA) staining, HE staining, PSR staining, and Masson trichrome staining, were used to assess cardiac function, cardiomyocyte cross-sectional area, and fibrosis levels in rats. Apoptosis in myocardial tissue and in vitro was detected by TUNEL assay, while reactive oxygen species (ROS) content in tissues and cells was measured using DHE staining. Furthermore, the affinity of Prdx1 with Mat and PI3K was analyzed using computer-simulated molecular docking. Western blotting and RT-PCR were utilized to evaluate Prdx1 levels and proteins related to apoptosis and oxidative stress, as well as the mRNA levels of cardiac hypertrophy and fibrosis-related indicators. ResultsMat significantly alleviated cardiac hypertrophy and fibrosis induced by TAC, preserved cardiac function, and markedly reduced cardiomyocyte apoptosis and oxidative damage. In vitro, mat attenuated ang Ⅱ - induced hypertrophy of nrvms and activation of neonatal rat fibroblasts. Notably, activation of the PI3K/Akt/FoxO1 pathway and downregulation of Prdx1 expression were observed in TAC mice; however, these effects were reversed by Mat treatment. Furthermore, Prdx1 knockdown activated the PI3K/Akt/FoxO1 pathway, leading to exacerbation of the disease. Molecular docking indicated that Molecular docking indicated that Mat upregulated Prdx1 expression by binding to it, thereby inhibiting the PI3K/Akt/FoxO1 pathway and protecting the heart by restoring Prdx1 expression levels. ConclusionMatairesinol alleviates pressure overload-induced cardiac remodeling both in vivo and in vitro by upregulating Prdx1 expression and inhibiting the PI3K/Akt/FoxO1 pathway. This study highlights the therapeutic potential of Matairesinol in the treatment of cardiac hypertrophy and remodeling, providing a promising avenue for future research and clinical application.

Protective effects of tetramethylpyrazine on myocardial ischemia/reperfusion injury involve NLRP3 inflammasome suppression by autophagy activation

Tetramethylpyrazine (TMP) belongs to the active ingredients of the traditional Chinese medicine Chuanxiong, which has a certain protective effect in myocardial ischemia–reperfusion (I/R) injury. It can improve postoperative cardiac function and alleviate ventricular remodeling in acute myocardial infarction patients. However, its specific protective mechanism is still unclear. In this study, a certain concentration of TMP was introduced into I/R mice or H9C2 cells after oxygen-glucose deprivation/reoxygenation (OGD/R) treatment to observe the effects of TMP on cardiomyocyte activity, cytotoxicity, apoptosis, autophagy, pyroptosis, and NLRP3 inflammasome activation. The results displayed that TMP intervention could reduce OGD/R and I/R-induced cardiomyocyte apoptosis, accelerate cellular activity and autophagy levels, and ameliorate myocardial tissue necrosis in I/R mice in a dose-dependent manner. Further, TMP prevented the formation of NLRP3 inflammasomes to suppress pyroptosis by increasing the level of cardiomyocyte autophagy after I/R and OGD/R modelling, the introduction of chloroquine to suppress autophagic activity in vivo and in vitro was further analyzed to confirm whether TMP inhibits NLRP3 inflammasome activation and pyroptosis by increasing autophagy, and we found the inhibitory effect of TMP on NLRP3 inflammasomes and its protective effect against myocardial injury were blocked when autophagy was inhibited with chloroquine. In conclusion, this experiment demonstrated that TMP unusually attenuated I/R injury in mice, and this protective effect was achieved by inhibiting the activation of NLRP3 inflammasomes through enhancing autophagic activity.

MiR-24-3p modulates cardiac function in doxorubicin -induced heart failure via the Sp1/PI3K signaling pathway

PurposeThe goal of this research was to explore the role of miR-24-3p in heart failure (HF), with a focus on its impact on the specificity protein 1 (Sp1)/phosphoinositide 3-kinase (PI3K) pathway. MethodsHF rat and HF cell models were established using doxorubicin(Dox). Cardiac function was assessed through echocardiography, while histological changes were observed via hematoxylin-eosin (HE) staining. To further investigate the underlying mechanisms, HF cell models were treated with either an Sp1 inhibitor or a PI3K inhibitor. Additionally, models with miR-24-3p overexpression or silencing were constructed. N-terminal pro-brain natriuretic peptide (NT-proBNP) levels were determined by ELISA. Cell apoptosis was evaluated using TUNEL staining, and lactate dehydrogenase (LDH) levels were measured by colorimetry. Reactive oxygen species (ROS) production was analyzed using flow cytometry. Related gene and protein expressions were assessed via qRT-PCR and Western blotting. Finally, the relationship between miR-24-3p and Sp1 was confirmed through dual-luciferase assays. ResultsDox treatment increased the left ventricular internal diameter (LVIDd) while decreasing ejection fraction (EF) and fractional shortening (FS), leading to disorganized cardiomyocyte arrangement, cellular edema, and necrosis in rats. In HF rats, NT-proBNP, Caspase-3, and miR-24-3p expression levels were elevated, whereas Sp1 and PI3K mRNA and protein expression levels were decreased. Similarly, Dox-induced damage in H9c2 cardiomyocytes resulted in increased NT-proBNP, apoptosis, Caspase-3, LDH, ROS, and miR-24-3p expression, along with decreased Sp1 and PI3K expression. Treatment with either Sp1 or PI3K inhibitors exacerbated the Dox-induced cardiomyocyte damage, further elevating NT-proBNP, apoptosis, Caspase-3, LDH, ROS, and miR-24-3p expression levels. Notably, Sp1 inhibition reduced PI3K expression, and PI3K inhibition, in turn, suppressed Sp1 expression. Overexpression of miR-24-3p worsened Dox-induced cardiomyocyte damage, characterized by increased NT-proBNP, apoptosis, Caspase-3, LDH, and ROS expression, alongside reduced Sp1 and PI3K expression. In contrast, silencing miR-24-3p mitigated these detrimental effects and increased Sp1 and PI3K expression. Dual-luciferase assays confirmed that miR-24-3p directly targets Sp1. ConclusionDox induces cardiomyocyte damage, impairs cardiac function, and promotes cardiomyocyte apoptosis and oxidative stress. Silencing miR-24-3p offers a protective effect by activating the Sp1/PI3K signaling pathway in heart failure.

Microparticle Mediated Delivery of Apelin Improves Heart Function in Post Myocardial Infarction Mice.

Apelin is an endogenous prepropeptide that regulates cardiac homeostasis and various physiological processes. Intravenous injection has been shown to improve cardiac contractility in patients with heart failure. However, its short half-life prevents studying its impact on left ventricular remodeling in the long term. Here, we aim to study whether microparticle-mediated slow release of apelin improves heart function and left ventricular remodeling in mice with myocardial infarction (MI). A cardiac patch was fabricated by embedding apelin-containing microparticles in a fibrin gel scaffold. MI was induced via permanent ligation of the left anterior descending coronary artery in adult C57BL/6J mice followed by epicardial patch placement immediately after (acute MI) or 28 days (chronic MI) post-MI. Four groups were included in this study, namely sham, MI, MI plus empty microparticle-embedded patch treatment, and MI plus apelin-containing microparticle-embedded patch treatment. Cardiac function was assessed by transthoracic echocardiography. Cardiomyocyte morphology, apoptosis, and cardiac fibrosis were evaluated by histology. Cardioprotective pathways were determined by RNA sequencing, quantitative polymerase chain reaction, and Western blot. The level of endogenous apelin was largely reduced in the first 7 days after MI induction and it was normalized by day 28. Apelin-13 encapsulated in poly(lactic-co-glycolic acid) microparticles displayed a sustained release pattern for up to 28 days. Treatment with apelin-containing microparticle-embedded patch inhibited cardiac hypertrophy and reduced scar size in both acute and chronic MI models, which is associated with improved cardiac function. Data from cellular and molecular analyses showed that apelin inhibits the activation and proliferation of cardiac fibroblasts by preventing transforming growth factor-β-mediated activation of Smad2/3 (supporessor of mothers against decapentaplegic 2/3) and downstream profibrotic gene expression. Poly(lactic-co-glycolic acid) microparticles prolonged the apelin release time in the mouse hearts. Epicardial delivery of the apelin-containing microparticle-embedded patch protects mice from both acute and chronic MI-induced cardiac dysfunction, inhibits cardiac fibrosis, and improves left ventricular remodeling.

Discovery of SIRT1-Activating Hydrogen Sulfide Donating Derivatives for Efficient Resistant of Myocardial Ischemic Injury.

Activating SIRT1 or promoting SIRT1 expression are both protective against myocardial ischemia. Combining these approaches would be an effective strategy for treating ischemic heart disease. Herein, we identified lead compounds with SIRT1 activation activity through screening the natural product library, and five series of H2S donating derivatives were designed and synthesized. Among them, compound 17 exerted an effective cardioprotective effect in vitro and in vivo. The addition of H2S scavenger attenuated the protective activity, emphasizing the critical involvement of H2S in the myocardial ischemia process. Interestingly, 17 exhibited stronger direct SIRT1 activative ability and induced higher SIRT1 expression capability compared to the lead. Furthermore, 17 attenuates oxidative stress-induced cardiomyocytes apoptosis by activating the SIRT1-PGC1α signaling pathway. Our study validated the promising potential of activating SIRT1 and promoting SIRT1 expression through H2S to improve cardiomyocytes function, providing novel insights into the protective mechanisms during the progression of ischemic heart disease.

Traditional Chinese medication qili qiangxin capsule protects against myocardial ischemia-reperfusion injury through suppressing autophagy via the phosphoinositide 3-kinase/protein kinase B/forkhead box O3 axis

Ethnopharmacological relevancePositive evidence from clinical trials highlights the promising potential of traditional Chinese medication, Qili qiangxin capsule (QLQX), on chronic heart failure; however, limited data are available regarding its effects and mechanism in myocardial ischemia-reperfusion injury (MIRI). Herein, we aimed to explore cardioprotective effects and the underlying mechanism of QLQX in MIRI in vivo and in vitro. Materials and methodsMice were subjected to left anterior descending coronary artery ligation for 30 min followed by 24 h of reperfusion with or without 7-day pretreatment with QLQX (0.234, 0.468, or 0.936 g/kg). Cardiac function, myocardial infarction, and morphological changes were evaluated. The mechanism underlying the cardio-protection of QLQX on MIRI was determined by network pharmacology based on the common genes of potential targets of QLQX and MIRI-related genes, further validated by H9c2 cardiomyocytes exposing hypoxia/reoxygenation (H/R). The viability, apoptosis, as well as autophagy and relevant signaling proteins in H9c2 were analyzed. ResultsQLQX pretreatment markedly improved cardiac function and decreased myocardium infarct size, apoptotic cardiomyocyte number, and LHD, CK-MB, and TnT levels in MIRI mice. QLQX could mitigate H/R-induced H9c2 cardiomyocyte injury, as evidenced by decreased cell apoptosis and LDH release and increased ATP production. QLQX effectively attenuates excessive autophagy in cardiomyocytes both in vivo and in vitro. Mechanically, network pharmacology analysis demonstrated the cardio-protection of QLQX on MIRI involving in PI3K/Akt signaling; the effects of QLQX on H/R-induced H9c2 cardiomyocytes were abolished by a specific PI3K inhibitor. ConclusionQLQX protects against cardiomyocyte apoptosis and excessive autophagy via PI3K/Akt signaling during MIRI.

Treatment with a combination of myricitrin and exercise alleviates myocardial infarction in rats via suppressing Nrf2/HO-1 antioxidant pathway

Myocardial infarction (MI) is the primary source of death in cardiovascular diseases. Myricitrin (MYR) is a phenolic compound known for its antioxidant properties. This study aimed to investigate the impact of MYR alone or combined with exercise on a rat model of MI and its underlying mechanism. Sprague-Dawley rats were randomized into 5 groups: sham-operated (Sham), MI-sedentary (MI-Sed), MI-exercise (MI-Ex), MI-sedentary + MYR (MI-Sed-MYR) and MI-exercise + MYR (MI-Ex-MYR). MI was induced through ligation of left anterior descending coronary artery. The treatment with exercise or MYR (30 mg/kg/d) gavage began one week after surgery, either individually or in combination. After 8 weeks, the rats were assessed for cardiac function. Myocardial injuries were estimated using triphenyltetrazolium chloride, sirius red and Masson staining. Changes in reactive oxygen species (ROS) levels, mitochondrial membrane potential (ΔΨm), apoptosis and Nrf2/HO-1 pathway were analyzed by ROS kit, JC-1 kit, TUNEL assay, Western blot and immunohistochemistry. Both MYR and exercise treatments improved cardiac function, reduced infarct size, suppressed collagen deposition, and decreased myocardial fibrosis. Additionally, both MYR and exercise treatments lowered ROS production induced by MI, restored ΔΨm, and attenuated oxidative stress and apoptosis in cardiomyocytes. Importantly, the combination of MYR and exercise showed greater efficacy compared to individual treatments. Mechanistically, the combined intervention activated the Nrf2/HO-1 signaling pathway. These findings suggest that the synergistic effect of MYR and exercise may offer a promising therapeutic approach for alleviating MI.

Minocycline alleviates lipopolysaccharide-induced cardiotoxicity by suppressing the NLRP3/Caspase-1 signaling pathway.

Minocycline (Min), as an antibiotic, possesses various beneficial properties such as anti-inflammatory, antioxidant, and anti-apoptotic effects. Despite these known qualities, the precise cardioprotective effect and mechanism of Min in protecting against sepsis-induced cardiotoxicity (SIC) remain unspecified. To address this, our study sought to assess the protective effects of Min on the heart. Lipopolysaccharide (LPS) was utilized to establish a cardiotoxicity model both in vivo and in vitro. Min was pretreated in the models. In the in vivo setting, evaluation of heart tissue histopathological injury was performed using hematoxylin and eosin (H&E) staining and TUNEL. Immunohistochemistry (IHC) was employed to evaluate the expression levels of NLRP3 and Caspase-1 in the heart tissue of mice. During in vitro experiments, the viability of H9c2 cells was gauged utilizing the CCK8 assay kit. Intracellular ROS levels in H9c2 cells were quantified using a ROS assay kit. Both in vitro and in vivo settings were subjected to measurement of oxidative stress indexes, encompassing glutathione (GSH), malondialdehyde (MDA), and superoxide dismutase (SOD) levels. Additionglly, myocardial injury markers like lactate dehydrogenase (LDH) and creatine kinase MB (CK-MB) activity were quantified using appropriate assay kits. Western blotting (WB) analysis was conducted to detect the expression levels of NOD-like receptor protein-3 (NLRP3), caspase-1, IL-18, and IL-1β, alongside apoptosis-related proteins such as Bcl-2 and Bax, and antioxidant proteins including superoxide dismutase-1 (SOD-1) and antioxidant proteins including superoxide dismutase-1 (SOD-2), both in H9c2 cells and mouse heart tissues. In vivo, Min was effective in reducing LPS-induced inflammation in cardiac tissue, preventing cell damage and apoptosis in cardiomyocytes. The levels of LDH and CK-MB were significantly reduced with Min treatment. In vitro studies showed that Min improved the viability of H9C2 cells, reduced apoptosis, and decreased ROS levels in these cells. Further analysis indicated that Min decreased the protein levels of NLRP3, Caspase-1, IL-18, and IL-1β, while increasing the levels of SOD-1 and SOD-2 both in vivo and in vitro. Min alleviates LPS-induced SIC by suppressing the NLRP3/Caspase-1 signalling pathway in vivo and in vitro.

Exposure to Polypropylene Microplastics Causes Cardiomyocyte Apoptosis Through Oxidative Stress and Activation of the MAPK-Nrf2 Signaling Pathway.

Microplastics are a growing concern as pollutants that impact both public health and the environment. However, the toxic effects of polypropylene microplastics (PP-MPs) are not well understood. This study aimed to investigate the effects of PP-MPs on cardiotoxicity and its underlying mechanisms. The cardiotoxicity of exposure to different amounts of PP-MPs were investigated in both ICR mice and H9C2 cells. Our results demonstrated that sub-chronic exposure to 5 and 50 mg/L PP-MPs led to myocardial structural damage, apoptosis, and fibrosis in mice cardiomyocytes. Flow cytometry analysis revealed that PP-MPs could decrease mitochondrial membrane potential and induce apoptosis in H9C2 cells. Western blotting revealed decreased expression of Bcl-2, poly(ADP-ribose) polymerase (PARP) and caspase 3 and increased expression of Bax, cleaved-PARP, and cleaved-caspase 3 in PP-MPs-treated cardiac tissue and H9C2 cells. These results confirmed the apoptotic effects induced by PP-MPs. Moreover, PP-MPs treatment triggered oxidative stress, as evidenced by the increased levels of malondialdehyde; reduction in glutathione peroxidase, superoxide dismutase, and catalase activities in mice cardiac tissues; and increased reactive oxygen species levels in H9C2 cells. Finally, western blotting demonstrated that exposure to PP-MPs significantly reduced the expression levels of Nrf2 and p-ERK proteins associated with MAPK-Nrf2 pathway in both cardiac tissue and H9C2 cells. Overall, our findings indicate that PP-MPs can induce cardiomyocyte apoptosis through MAPK-Nrf2 signaling pathway, which is triggered by oxidative stress. This study provides a foundation for determining the effects of PP-MPs on cardiotoxicity and their underlying mechanisms.

Key subdomains of mesencephalic astrocyte-derived neurotrophic factor attenuate myocardial ischemia/reperfusion injury by JAK1/STAT1/NF-κB signaling pathway

BackgroundMyocardial ischemia/reperfusion (I/R) injury is a common pathological process in clinical practice. Developing effective therapeutic strategies to reduce or prevent this injury is crucial. The article aimed to investigate the role and mechanism of mesencephalic astrocyte-derived neurotrophic factor (MANF) and its key subdomains in modulating myocardial I/R-induced cardiomyocyte apoptosis.MethodsMANF stable knockout cell line and MANF mutant overexpression plasmids were constructed. The effects of MANF and mutants on apoptosis and endoplasmic reticulum (ER) stress related proteins were evaluated in hypoxia/reoxygenation-induced HL-1 cardiomyocytes by western blot, immunofluorescence, Tunel and flow cytometry. Echocardiography, ELISA, TTC and Masson were used to observe the effects of recombinant MANF protein (rMANF) on cardiac function in myocardial I/R mice.ResultsThis study observed increased expression of MANF in both myocardial infarction patients and I/R mice. MANF overexpression in cardiomyocytes decreased ER stress-induced apoptosis, while MANF knockout exacerbated it. rMANF improved cardiac function in I/R mice by reducing injury and inflammation. This study specifically demonstrates that mutations in the α-helix of MANF were more effective in reducing ER stress and cardiomyocyte apoptosis. Mechanistically, MANF and the α-helix mutant attenuated I/R injury by inhibiting the JAK1/STAT1/NF-κB signaling pathway in addition to reducing ER stress-induced apoptosis.ConclusionThese findings highlight MANF and its subdomains as critical regulators of myocardial I/R injury, offering promising therapeutic targets with significant clinical implications for I/R-related diseases.

Glucose fluctuations aggravate cardiomyocyte apoptosis by enhancing the interaction between Txnip and Akt

BackgroundGlucose 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.MethodsDiabetic 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.ResultsThe 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.ConclusionsGlucose fluctuations lead to cardiomyocyte apoptosis by up-regulating Txnip expression and enhancing Txnip-Akt interaction.