Cardiomyocyte Apoptosis Research Articles

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.

Erxian decoction ameliorates myocardial tissue damage through activating PI3K/AKT signaling pathway in ovariectomized rats

Background Erxian decoction (EXD) is an empirical formula for treating cardiovascular disease, our previous work has shown that EXD could improve the cardiovascular structure and function in ovariectomized (OVX) rats, but its pharmacological mechanism is still unclear. Materials and Methods Network pharmacology was utilized to assess the key active components and central targets of EXD in treating postmenopausal cardiovascular disease. Then, an OVX rat model was established, HE staining and transmission electron microscope were utilized to observe myocardial tissue morphology, TUNEL staining was utilized to detect cardiomyocyte apoptosis, western blot, and ELISA were used to confirm efficacy and pathway of EXD. Results The network pharmacology prediction results showed that 129 common targets were identified by intersecting EXD targets and postmenopausal cardiovascular disease targets, including AKT1, TNF, IL-6, IL-1β, PTGS2 and other core targets, apoptosis, PI3K/AKT, and other signaling pathways may be closely related to postmenopausal cardiovascular disease. After ovariectomy, the myocardial tissue of rats was damaged, the expression level of PI3K/AKT pathway-related molecules in the myocardial tissue were decreased, the apoptosis index of cardiomyocytes was increased, and the levels of inflammatory factors (TNF-α, IL-6, and IL-1β) were enhanced. EXD intervention could improve myocardial tissue injury, EXD could up-regulate the protein expression of PI3K and p-AKT in myocardial tissue, and thereby prevent myocardial cell apoptosis. At the same time, EXD downregulated the levels of inflammatory factors in serum of ovariectomized rats. Conclusion EXD may prevent myocardial tissue damage through induction of the PI3K/AKT signaling pathway, thereby reducing cardiomyocyte apoptosis and inflammation. EXD may be a potential drug for the treatment of postmenopausal cardiovascular disease.

Bezafibrate mitigates cardiac injury against coronary microembolization by preventing activation of p38 MAPK/NF-κB signaling.

Coronary microembolization (CME)-induced inflammatory response and cardiomyocyte apoptosis are the main contributors to CME-associated myocardial dysfunction. Bezafibrate, a peroxisome proliferator-activated receptors (PPARs) agonist, has displayed various benefits in different types of diseases. However, it is unknown whether Bezafibrate possesses a protective effect in myocardial dysfunction against CME. In this study, we aimed to investigate the pharmacological function of Bezafibrate in CME-induced insults in myocardial injury and progressive cardiac dysfunction and explore the underlying mechanism. A CME model was established in rats, and cardiac function was detected. The levels of injury biomarkers in serum including CK-MB, AST, and LDH were determined using commercial kits, and pro-inflammatory mediators including TNF-α and IL-6 were detected using ELISA kits. Our results indicate that Bezafibrate improved cardiac function after CME induction. Bezafibrate reduced the release of myocardial injury indicators such as CK-MB, AST, and LDH in CME rats. We also found that Bezafibrate ameliorated oxidative stress by increasing the levels of the antioxidant GPx and the activity of SOD and reducing the levels of TBARS and the activity of NOX. Bezafibrate inhibited the expression of pro-inflammatory cytokines such as TNF-α and IL-6. Importantly, Bezafibrate was found to mitigate CME-induced myocardial apoptosis by increasing the expression of Bcl-2 and reducing the levels of Bax and cleaved caspase-3. Mechanistically, Bezafibrate could prevent the activation of p38 MAPK/NF-κB signaling. These findings suggest that Bezafibrate may be a candidate therapeutic agent for cardioprotection against CME in clinical applications.

Carbon monoxide-releasing molecule-3 ameliorates traumatic brain injury-induced cardiac dysfunctions via inhibition of pyroptosis and apoptosis.

Traumatic brain injury (TBI) frequently results in cardiac dysfunction and impacts the quality of survivors' life. It has been reported that carbon monoxide-releasing molecule-3 (CORM-3) administration immediately after hemorrhagic shock and resuscitation (HSR) ameliorated the HSR‑induced cardiac dysfunctions. The purpose of this study was to determine whether the application of CORM-3 on TBI exerted therapeutic effects against TBI-induced cardiac dysfunctions. Rats were randomly divided into four groups (n = 12) including Sham, TBI, TBI/CORM-3 and TBI/inactive CORM-3 (iCORM-3) groups. TBI was established by a weight-drop model. The rats in the TBI/CORM-3 group and TBI/iCORM-3 group were intravenously injected with CORM-3 and iCORM-3 (4mg/kg) following TBI, respectively. The time of death in the rats that did not survive within 24h was recorded. 24h post-trauma, the cardiac function, pathological change, serum troponin T and creatine kinase-MB (CK-MB) levels, pyroptosis, apoptosis and expressions of TUNEL staining, Gasdermin D (GSDMD), IL-1β, IL-18, ratio Bax/Bcl-2 were assessed by echocardiography, hematoxylin-eosin staining, chemiluminescence, immunofluorescence, and western blot assays, respectively. TBI-treated rats exhibited dramatically decreased ejection fraction and aggravated myocardial injury, increased mortality rate, elevated levels of serum troponin T and CK-MB, promoted cardiac pyroptosis and apoptosis, and upregulated expressions of cleaved caspase-3, GSDMD N-terminal fragments, IL-1β, IL-18, and ratio of Bax/Bcl-2, whereas CORM-3 partially reversed these changes. CORM-3 ameliorated TBI-induced cardiac injury and dysfunction. This mechanism may be responsible for the inhibition of pyroptosis and apoptosis in cardiomyocyte.

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.

Modelling myocardial ischemia/reperfusion injury with inflammatory response in human ventricular cardiac organoids.

Current therapeutic drug exploring targeting at myocardial ischemia/reperfusion (I/R) injury is limited due to the lack of humanized cardiac models that resemble myocardial damage and inflammatory response. Herein, we develop ventricular cardiac organoids from human induced pluripotent stem cells (hiPSCs) and simulate I/R injury by hypoxia/reoxygenation (H/R), which results in increased cardiomyocytes apoptosis, elevated oxidative stress, disrupted morphological structure and decreased beat amplitude. RNA-seq reveals a potential role of type I interferon (IFN-I) in this I/R injury model. We then introduce THP-1 cells and reveal inflammatory responses between monocytes/macrophages and H/R-induced ventricular cardiac organoids. Furthermore, we demonstrate Anifrolumab, an FDA approved antagonist of IFN-I receptor, effectively decreases IFN-I secretion and related gene expression, attenuates H/R-induced inflammation and oxidative stress in the co-culture system. This study advances the modelling of myocardial I/R injury with inflammatory response in human cardiac organoids, which provides a reliable platform for preclinical study and drug screening.

LncRNA ZFAS1/miR-186-5p axis is involved in oxidative stress inhibition of myocardial ischemia-reperfusion injury by targeting BTG2

ABSTRACT Objective To probe the involvement of long noncoding RNA zinc finger antisense 1 (ZFAS1)/microRNA (miR)-186-5p axis in inhibiting oxidative stress in myocardial ischemia-reperfusion injury (MIRI) by targeting B-cell translocation gene 2 (BTG2). Methods The MIRI mice model was established by ligating the left anterior descending branch of the left coronary artery in C57BL/6 mice. The in vitro MIRI model was constructed by hypoxia and reoxygenation of HL-1 cardiomyocytes. Cardiomyocyte apoptosis and the extent of myocardial injury in mice were detected. The apoptosis rates, malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in HL-1 cells were assessed. The relationship among ZFAS1, miR-186-5p, and BTG2 was verified. Results High ZFAS1 and BTG2 levels and low miR-186-5p levels were demonstrated in I/R-injured myocardial tissues and in H/R-treated cardiomyocytes. Interference with ZFAS1 or elevation of miR-186-5p inhibited apoptosis and oxidative stress in H/R model cardiomyocytes and I/R-injured myocardial tissues. Overexpressing BTG2 impaired the ameliorative effects of miR-186-5p on MIRI. ZFAS1 negatively regulated miR-186-5p expression by acting as a molecular sponge. miR-186-5p targeted to regulate BTG2 negatively. Conclusion Interfering with ZFAS1 can upregulate miR-186-5p and thus inhibit BTG2 expression, thereby ameliorating MIRI.

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.

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.

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.

Effect of mitochondrial translocator protein TSPO on LPS-induced cardiac dysfunction

IntroductionSepsis-induced cardiac dysfunction is one of the most serious complications of sepsis. The mitochondrial translocator protein (TSPO), a mitochondrial outer membrane protein, is widely used as a diagnostic marker of inflammation-related diseases and can also lead to the release of inflammatory components. However, whether TSPO has a therapeutic effect on sepsis-induced cardiac dysfunction is unclear. ObjectivesThe aim of this study is to investigate the involvement of TSPO in the pathogenesis of sepsis-induced cardiac dysfunction and elucidate its underlying mechanism, as well as develop therapeutic strategies targeting TSPO for the prevention and treatment of sepsis-induced cardiac dysfunction. MethodsThe sepsis-induced cardiac dysfunction model was established by intraperitoneal injection of lipopolysaccharide (LPS) in C57BL/6 mice (LPS-induced cardiac dysfunction, LICD). TSPO knockout mice were constructed,and the effects of TSPO was detected by survival rate, echocardiography, HE staining, mitochondrial electron microscopy, TUNEL staining. TSPO-binding proteins were identified by co-immunoprecipitation and mass spectrometry. The mechanisms underlying between TSPO and voltage-dependent anion channel (VDAC) was studied through western blot and immunofluorescence. Proteolysis-Targeting Chimeras (PROTAC) technology was used to construct TSPO-PROTAC molecules that can degrade TSPO. ResultsOur present study found that LPS increased cardiac TSPO expression. Knockout of TSPO in C57BL/6 mice with LICD attenuated the cardiac pathology, mitochondrial dysfunction, and apoptosis of cardiomyocytes and significantly improved cardiac function and survival rate. Co-immunoprecipitation and mass spectrometry identified VDAC as a TSPO binding protein.Down-regulation of TSPO reduced PKA-mediated VDAC phosphorylation and VDAC oligomerization, ameliorated mitochondrial function, and reduced cardiomyocyte apoptosis. The study has clinical translational potential, because administration of TSPO-PROTAC to degrade TSPO improved cardiac function in mice with LICD. ConclusionThis study elucidated the effect of TSPO in LICD, providing a new therapeutic strategy to down-regulate TSPO by administration of TSPO-PROTAC for the prevention and treatment of LICD.

Differential expression of cardiometabolic and inflammation markers and signaling pathways between overweight/obese Qatari adults with high and low plasma salivary α-amylase activity.

The relationship between salivary α-amylase activity (sAAa) and susceptibility to cardiovascular disorders lacks a definitive consensus in available studies. To fill this knowledge gap, the present study endeavors to investigate this association among overweight/obese otherwise healthy Qatari adults. The study specifically categorizes participants based on their sAAa into high and low subgroups, aiming to provide a more comprehensive understanding of the potential link between sAAa levels and cardiovascular and inflammation markers in this population. Plasma samples of 264 Qatari overweight/obese (Ow/Ob) participants were used to quantify the sAAa and to profile the proteins germane to cardiovascular, cardiometabolic, metabolism, and organ damage in low sAAa (LsAAa) and high sAAa (HsAAa) subjects using the Olink technology. Comprehensive statistical tools as well as chemometric and enrichments analyses were used to identify differentially expressed proteins (DEPs) and their associated signaling pathways and cellular functions. A total of ten DEPs were detected, among them five were upregulated (QPCT, LCN2, PON2, DPP7, CRKL) while five were down regulated in the LsAAa subgroup compared to the HsAAa subgroup (ARG1, CTSH, SERPINB6, OSMR, ALDH3A). Functional enrichment analysis highlighted several relevant signaling pathways and cellular functions enriched in the DEPs, including myocardial dysfunction, disorder of blood pressure, myocardial infraction, apoptosis of cardiomyocytes, hypertension, chronic inflammatory disorder, immunes-mediated inflammatory disease, inflammatory response, activation of leukocytes and activation of phagocytes. Our study unveils substantial alterations within numerous canonical pathways and cellular or molecular functions that bear relevance to cardiometabolic disorders among Ow/Ob Qatari adults exhibiting LsAAa and HsAAa in the plasma. A more comprehensive exploration of these proteins and their associated pathways and functions offers the prospect of elucidating the mechanistic underpinnings inherent in the documented relationship between sAAa and metabolic disorders.

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.

CHK1 attenuates cardiac dysfunction via suppressing SIRT1-ubiquitination

BackgroundMitochondrial dysfunction is linked to myocardial ischemia-reperfusion (I/R) injury. Checkpoint kinase 1 (CHK1) could facilitate cardiomyocyte proliferation, however, its role on mitochondrial function in I/R injury remains unknown. MethodsTo investigate the role of CHK1 on mitochondrial function following I/R injury, cardiomyocyte-specific knockout/overexpression mouse models were generated. Adult mouse cardiomyocytes (AMCMs) were isolated for in vitro study. Mass spectrometry-proteomics analysis and protein co-immunoprecipitation assays were conducted to dissect the molecular mechanism. ResultsCHK1 was downregulated in myocardium post I/R and AMCMs post oxygen-glucose deprivation/re‑oxygenation (OGD/R). In vivo, CHK1 overexpression protected against I/R induced cardiac dysfunction, while heterogenous CHK1 knockout exacerbated cardiomyopathy. In vitro, CHK1 inhibited OGD/R-induced cardiomyocyte apoptosis and bolstered cardiomyocyte survival. Mechanistically, CHK1 attenuated oxidative stress and preserved mitochondrial metabolism in cardiomyocytes under I/R. Moreover, disrupted mitochondrial homeostasis in I/R myocardium was restored by CHK1 through the promotion of mitochondrial biogenesis and mitophagy. Through mass spectrometry analysis following co-immunoprecipitation, SIRT1 was identified as a direct target of CHK1. The 266–390 domain of CHK1 interacted with the 160–583 domain of SIRT1. Importantly, CHK1 phosphorylated SIRT1 at Thr530 residue, thereby inhibiting SMURF2-mediated degradation of SIRT1. The role of CHK1 in maintaining mitochondrial dynamics control and myocardial protection is abolished by SIRT1 inhibition, while inactivated mutation of SIRT1 Thr530 fails to reverse the impaired mitochondrial dynamics following CHK1 knockdown. CHK1 Δ390 amino acids (aa) mutant functioned similarly to full-length CHK1 in scavenging ROS and maintaining mitochondrial dynamics. Consistently, cardiac-specific SIRT1 knockdown attenuated the protective role of CHK1 in I/R injury. ConclusionsOur findings revealed that CHK1 mitigates I/R injury and restores mitochondrial dynamics in cardiomyocytes through a SIRT1-dependent mechanism.

Aptamer BT200 is protective against myocardial ischemia-reperfusion injury in mice

BackgroundMyocardial ischemia-reperfusion (MI/R) injury tends to affect cardiac function and leads to poor patient prognosis, and there is still no effectively targeted drug to develop anti–von Willebrand factor (VWF) aptamer in acute coronary heart disease. However, the newly anti-VWF aptamer BT200 is applied for not only stroke and hemophilia but also antithrombolism function in clinical development. The role of BT200 in acute myocardial injury during MI/R is still unknown. ObjectivesTo investigate the cardioprotective effect of aptamer BT200 in an experiment mouse model of MI/R. MethodsC57BL/6 mice were subjected to 30-minute ischemia and 24-hour reperfusion to establish MI/R model. Mice were treated with intravenous injection of cy3-labeled BT200 and were observed by an in vivo imaging system at different time points. Then, mice were sampled and evaluated by echocardiography, Evans triphenyltetrazolium chloride staining, histopathologic, western blotting, and real-time quantitative polymerase chain reaction assays to detect cardiac injury and inflammation response after 24-hour reperfusion. ResultsBT200 aptamer can enter and infiltrate into the ischemic myocardium after 24-hour reperfusion. BT200 was shown to inhibit VWF A1 activity and prolong bleeding time in MI/R mice. Moreover, BT200-treated mice had a significant reduction in infarct size and an improvement in cardiac function post-MI/R. BT200 treatment can also alleviate MI/R-induced microvascular obstruction, inflammation response, and cardiomyocyte apoptosis. ConclusionPharmacologic targeting of VWF with BT200 alleviates acute MI/R injury in a murine model and may be a novel therapy strategy for acute myocardial infarction.

Perfluorooctanoic acid (PFOA) induces cardiotoxicity by activating the Keap1/Nrf2 pathway in zebrafish (Danio rerio) embryos

Perfluorooctanoic acid (PFOA), a perfluoroalkyl compound, is linked to congenital heart diseases, though its underlying mechanisms remain unclear. We hypothesized that PFOA induces cardiac defects through the inhibition of the Keap1/Nrf2 pathway, leading to oxidative damage in cardiomyocytes. In this study, zebrafish embryos exposed to PFOA showed significant cardiac malformations and dysfunction, characterized by excessive reactive oxygen species (ROS), malondialdehyde (MDA) production, decreased superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities. Additionally, we observed dysregulation in the expression of key cardiac development genes (vmhc, gata4, nkx2.5, and sox9b). PFOA also reduced the expression of keap1, nrf2, and ho-1. After overexpression of Nrf2, levels of ROS and MDA decreased, while levels of SOD, CAT, and GSH-Px increased. Additionally, cardiomyocyte apoptosis and cardiac malformations were alleviated. These findings have suggested that PFOA induces oxidative stress through Keap1/Nrf2 pathway inhibition, ultimately leading to cardiac defects.

Disruption of BACH1 Protects AC16 Cardiomyocytes Against Hypoxia/Reoxygenation-Evoked Injury by Diminishing CDKN3 Transcription.

Reperfusion after myocardial infarction (MI) can lead to myocardial ischemia/reperfusion (I/R) damage. The transcription factor (TF) broad-complex, tramtrack, and bric-a-brac (BTB) and cap'n'collar (CNC) homology 1 (BACH1) is implicated in the injury. However, the downstream mechanisms of BACH1 in affecting myocardial hypoxia/reoxygenation (H/R) damage are still fully understood. AC16 cells were stimulated with H/R conditions to model cardiomyocytes under H/R. mRNA analysis was performed by quantitative real-time PCR. Protein levels were gauged by immunoblot analysis. The effect of BACH1/cyclin-dependent kinase inhibitor 3 (CDKN3) on H/R-evoked injury was assessed by measuring cell viability via Cell Counting Kit-8 (CCK-8), apoptosis (flow cytometry and caspase 3 activity), ferroptosis via Fe2+, glutathione (GSH), reactive oxygen species (ROS) and malondialdehyde (MDA) markers and inflammation cytokines interleukin-1beta (IL-1β) and tumor necrosis factor alpha (TNF-α). The BACH1/CDKN3 relationship was examined by chromatin immunoprecipitation (ChIP) experiment and luciferase assay. BACH1 was increased in MI serum and H/R-stimulated AC16 cardiomyocytes. Functionally, disruption of BACH1 mitigated H/R-evoked in vitro apoptosis, ferroptosis and inflammation of AC16 cardiomyocytes. Mechanistically, BACH1 activated CDKN3 transcription and enhanced CDKN3 protein expression in AC16 cardiomyocytes. Our rescue experiments validated that BACH1 disruption attenuated H/R-evoked AC16 cardiomyocyte apoptosis, ferroptosis and inflammation by downregulating CDKN3. Additionally, BACH1 disruption could activate the adenosine monophosphate-activated protein kinase (AMPK) signaling by downregulating CDKN3 in H/R-stimulated AC16 cardiomyocytes. Our study demonstrates that BACH1 activates CDKN3 transcription to induce H/R-evoked damage of AC16 cardiomyocytes partially via AMPK signaling.

Spatiotemporal control of neutrophil fate to tune inflammation and repair for myocardial infarction therapy

Neutrophils are critical mediators of both the initiation and resolution of inflammation after myocardial infarction (MI). Overexuberant neutrophil signaling after MI exacerbates cardiomyocyte apoptosis and cardiac remodeling while neutrophil apoptosis at the injury site promotes macrophage polarization toward a pro-resolving phenotype. Here, we describe a nanoparticle that provides spatiotemporal control over neutrophil fate to both stymie MI pathogenesis and promote healing. Intravenous injection of roscovitine/catalase-loaded poly(lactic-co-glycolic acid) nanoparticles after MI leads to nanoparticle uptake by circulating neutrophils migrating to the infarcted heart. Activated neutrophils at the infarcted heart generate reactive oxygen species, triggering intracellular release of roscovitine, a cyclin-dependent kinase inhibitor, from the nanoparticles, thereby inducing neutrophil apoptosis. Timely apoptosis of activated neutrophils at the infarcted heart limits neutrophil-driven inflammation, promotes macrophage polarization toward a pro-resolving phenotype, and preserves heart function. Modulating neutrophil fate to tune both inflammatory and reparatory processes may be an effective strategy to treat MI.

Schisandrin C prevents Regorafenib-Induced cardiotoxicity by recovering EPHA2 expression in cardiomyocytes.

Regorafenib, an oral multikinase inhibitor of angiogenic, stromal, and oncogenic receptor tyrosine kinases, has been approved for the treatment of metastatic colorectal cancer, gastrointestinal stromal tumors and hepatocellular carcinoma by the US Food and Drug Administration and European Medicines Agency. However, regorafenib-induced cardiotoxicity increases the risk of mortality. Despite reports that regorafenib can cause mitochondrial dysfunction in cardiomyocytes, the molecular mechanism of regorafenib-induced cardiotoxicity is much less known and there is an urgent need for intervention strategies. Here, we treated mice with vehicle or 200 mg/kg regorafenib daily for 42 days by gavage or treated cardiomyocyte lines with 8, 16 or 32 μM regorafenib, and we found that regorafenib could cause apoptosis, mitochondrial injury and DNA damage in cardiomyocytes. Mechanistically, regorafenib can reduce the expression of EPHA2, which inhibits AKT signaling, leading to cardiomyocyte apoptosis and cardiotoxicity. In addition, we showed that recovering EPHA2 expression via plasmid-induced overexpression of EPHA2 or schisandrin C, a natural product, could prevent regorafenib-induced cardiotoxicity. These findings demonstrated that regorafenib causes cardiomyocyte apoptosis and cardiac injury by reducing the expression of EPHA2 and schisandrin C could prevent regorafenib-induced cardiotoxicity by recovering EPHA2 expression, which provides a potential management strategy for regorafenib-induced cardiotoxicity and will benefit the safe application of regorafenib in clinic.

Peptides are cardioprotective drugs of the future. Oxytocin

The widespread introduction of percutaneous coronary intervention (PCI) in the treatment of acute myocardial infarction (AMI) caused a significant reduction in the mortality rate from AMI in developed countries. However, over the past 10 years, there was no significant reduction in in-hospital mortality from AMI. It is clear that there is an urgent need to develop novel drugs that could effectively prevent reperfusion injury of the heart after successful recanalization of the infarct-related coronary artery. Enzyme-resistant peptide agonists of the oxytocin receptor could become a prototype for the creation of such drugs. It was shown oxytocin could selectively prevent cardiac reperfusion injury. The cardioprotective effect of oxytocin in coronary artery occlusion and myocardial reperfusion is distinguished by a decrease in infarct size, an improvement in cardiac contractility, and a decrease in the incidence of ventricular arrhythmias. In addition, oxytocin inhibits apoptosis and pyroptosis of cardiomyocytes in hypoxia/reoxygenation. It has been established that kinases, NO-synthase, and guanylyl cyclase are involved in an oxytocininduced increase in cardiac resistance to ischemia / reperfusion.