H9c2 Cardiomyocytes Research Articles

Synthesis of Quinoline and Dihydroquinoline Embelin Derivatives as Cardioprotective Agents.

A set of new dihydroquinoline embelin derivatives was obtained from the reaction of the natural benzoquinone embelin (1) with anilines and aromatic aldehydes in the presence of AgOTf. The synthesis of these compounds involves the formation of a Knoevenagel adduct, followed by nucleophilic addition of aniline and subsequent electrocyclic ring closure. The scope of the reaction regarding the aldehydes and anilines was determined. Quinoline derivatives were also obtained from the corresponding dihydroquinolines under oxidation with DDQ. The cardioprotective activity of the synthesized compounds was screened using a doxorubicin-induced cardiotoxicity model in H9c2 cardiomyocytes. Some structure-activity relationships were outlined, and the best activities were achieved with quinoline-embelin derivatives having a 4-nitrophenyl group attached at the pyridine ring. The obtained results indicated that embelin derivatives 4i, 6a, 6d, 6k, and 6m could have potential as cardioprotective agents, as they attenuated a DOX-induced cardiotoxicity effect acting on oxidative stress and apoptosis.

Kazinol B protects H9c2 cardiomyocytes from hypoxia/reoxygenation-induced cardiac injury by modulating the AKT/AMPK/Nrf2 signalling pathway

Context Kazinol B (KB), an isoprenylated flavan derived from Broussonetia kazinoki Sieb. (Moraceae) root, has long been used in folk medicine. Objective This study examines the protective effects of KB and its underlying mechanisms in hypoxia and reoxygenation (H/R)-induced cardiac injury in H9c2 rat cardiac myoblasts. Materials and methods H9c2 cells were incubated with various concentrations of KB (0, 0.3, 1, 3, 10 and 30 μM) for 2 h and then subjected to H/R insults. The protective effects of KB and its underlying mechanisms were explored. Results KB significantly elevated cell viability (1 μM, 1.21-fold; 3 μM, 1.36-fold, and 10 μM, 1.47-fold) and suppressed LDH release (1 μM, 0.77-fold; 3 μM, 0.68-fold, and 10 μM, 0.59-fold) in H/R-induced H9c2 cells. Further, 10 μM KB blocked apoptotic cascades, as shown by the Annexin-V/PI (0.41-fold), DNA fragmentation (0.51-fold), caspase-3 (0.52-fold), PARP activation (0.27-fold) and Bax/Bcl-2 expression (0.28-fold) assays. KB (10 μM) downregulated reactive oxygen species production (0.51-fold) and lipid peroxidation (0.48-fold); it upregulated the activities of GSH-Px (2.08-fold) and SOD (1.72-fold). KB (10 μM) induced Nrf2 nuclear accumulation (1.94-fold) and increased ARE promoter activity (2.15-fold), HO-1 expression (3.07-fold), AKT (3.07-fold) and AMPK (3.07-fold) phosphorylation. Nrf2 knockdown via using Nrf2 siRNA abrogated KB-mediated protective effects against H/R insults. Moreover, pharmacological inhibitors of AKT and AMPK also abrogated KB-induced Nrf2 activation and its protective function. Discussion and conclusions KB prevented H/R-induced cardiomyocyte injury via modulating the AKT and AMPK-mediated Nrf2 induction. KB might be a promising drug candidate for managing ischemic cardiac disorders.

Molecular chaperones HSP40, HSP70, STIP1, and HSP90 are involved in stabilization of Cx43.

To investigate the involvement of stress induced phosphoprotein 1 (STIP1), heat shock protein (HSP) 70, and HSP90 in ubiquitination of connexin 43 (Cx43) in rat H9c2 cardiomyocytes.Co-immunoprecipitation was used to detect protein-protein interactions and Cx43 ubiquitination. Immunofluorescence was used for protein co-localization. The protein binding, Cx43 protein expression, and Cx43 ubiquitination were reanalyzed in H9c2 cells with modified STIP1 and/or HSP90 expression.STIP1 bound to HSP70 and HSP90, and Cx43 bound to HSP40, HSP70, and HSP90 in normal H9c2 cardiomyocytes. Overexpression of STIP1 promoted the transition of Cx43-HSP70 to Cx43-HSP90 and inhibited Cx43 ubiquitination; knockdown of STIP1 resulted in the opposite effects. Inhibition of HSP90 counteracted the inhibitory effect of STIP1 overexpression on Cx43 ubiquitination.STIP1 suppresses Cx43 ubiquitination in H9c2 cardiomyocytes by promoting the transition of Cx43-HSP70 to Cx43-HSP90.

Knockdown of lncRNA SNHG16 attenuates myocardial ischemia‑reoxygenation injury via targeting miR‑183/FOXO1 axis.

Accumulating evidence shows that long non-coding RNAs (lncRNAs) are widely involved in cellular processes of myocardial ischemia/reperfusion (I/R). The present study investigated the functions of lncRNA SNHG16 in myocardial I/R and the mechanism mediated by SNHG16. The myocardial I/R rat and cell model and hypoxia/reoxygenation injury (H/R) models of H9C2 cardiomyocytes were established to detect the expression of SNHG16. Cell Counting Kit-8, flow cytometric and western blot assays were conducted to detect cell viability, apoptosis and protein expression. Myocardial cell apoptosis was assessed by TUNEL staining. Dual-luciferase gene reporter was applied to determine the interaction between the molecules. The expressions of SNHG16 were upregulated in myocardial I/R injury models. Inhibition of SNHG16 relieved myocardial I/R injury in vivo and in vitro silencing of SNHG16 alleviated H/R induced cardiomyocyte apoptosis. To explore the regulatory mechanism, it was discovered that SNHG16 directly interacted with miR-183, while forkhead box O1 (FoxO1) was a target of microRNA (miR)-183. Findings from rescue assays revealed that miR-183 inhibitor and upregulation of FOXO1 can rescue the effect of sh-SNHG16 on H/R-induced cardiomyocyte apoptosis. The results indicated that the lncRNA SNHG16/miR-183/FOXO1 axis exacerbated myocardial cell apoptosis in myocardial I/R injury, suggesting SNHG16 as a potential therapeutic target for myocardial I/R injury.

RING Finger Protein 10 Regulates AP-1/Meox2 to Mediate Pirarubicin-Induced Cardiomyocyte Apoptosis.

Pirarubicin (THP) is one of the classic chemotherapy drugs for cancer treatment. It is often clinically limited because of its cardiotoxicity. The occurrence and development of THP-mediated chemotherapy-related cardiotoxicity (CRC) may be reversed by RING finger protein 10 (RNF10). This study was performed with the aim of evaluating the inhibitory effect of RNF10 on THP-mediated CRC and its molecular mechanism. In vivo, we found that the expression of RNF10 decreased in THP-induced CRC rats, accompanied by Meox2 inhibition and AP-1 activation, resulting in increased cardiomyocyte apoptosis. After small interfering RNA (siRNA) and lentivirus transfection (Lv) of RNF10 in vitro, the expression of RNF10, Meox2, and AP-1 proteins and the degree of cardiomyocyte apoptosis were detected. We found that overexpression of RNF10 in H9C2 cardiomyocytes significantly promoted Meox2 and inhibited AP-1, alleviated apoptosis, and showed further inhibitory activity on THP-induced cardiomyocyte toxicity. Silencing RNF10 showed the opposite result. Our study showed that RNF10 inhibited THP-induced CRC through the activity of Meox2 and AP-1 proteins. RNF10 may be the next drug target for the treatment of CRC and other related cardiovascular diseases.

(+)/(−)-Alexanoid A, a pair of enantiomeric sesquiterpenoid with a novel 5/6/6 tricyclic backbone from the stem of Syringa pinnatifolia

A pair of enantiomeric sesquiterpenoid, namely (+)/(−)-alexanoid A (1a and 1b), with an unprecedented 4,11,11-trimethyltricyclo[6.3.1.01,5] dodecane skeleton (proposed alexane), was discovered from the peeled stems of Syringa pinnatifolia Hemsl. The structures were elucidated by the spectroscopic data analysis including NMR, UV, IR, optical rotation (OR), and electronic circular dichroism (ECD) calculation, and the protective activity on H9c2 cardiomyocytes and anti-inflammatory activity against NO production in lipopolysaccharide (LPS)-induced RAW264.7 cells were evaluated.

A four-compound remedy AGILe protected H9c2 cardiomyocytes against oxygen glucose deprivation via targeting the TNF-α/NF-κB pathway: Implications for the therapy of myocardial infarction.

Myocardial infarction (MI) is a highly prevalent and lethal disease worldwide. Prevention and timely recovery are critical for the control of the recurrence and heart failure in MI survivors. The present study was designed to investigate the cardioprotective activity of the herbal medicine formula Baoyuan Decoction (BYD) and identify the active compounds and molecular targets. The ethanolic BYD extract (BYDE) was prepared by water extraction and ethanol precipitation of four herbal medicines, Astragali Radix, Ginseng Radix et Rhizoma, Cinnamomi Cortex, and Glycyrrhizae Radix et Rhizoma. Initially, BYDE was validated for the cardioprotective effectiveness in a mouse model of ischemia injury and rat cardiomyocyte H9C2 cells. As results, BYDE effectively reduced infarct size from 56% to 37% and preserved cardiac functions in mouse MI model while protected H9C2 cells against oxygen glucose deprivation. Subsequent network pharmacology analysis revealed that 122 bioactive ingredients, including flavonoids and saponins from the UPLC-MS/MS profile of BYDE, might target 37 MI-related proteins, including inflammatory and apoptotic mediators (e.g., TNF, NFKB1, CASPs, TNFRSF1A, CXCL12, BCL2A1). Pathway enrichment analysis suggested that BYDE might control the cardiac inflammation via targeting the tumor necrosis factor-alpha (TNF-α)/nuclear factor-κB (NF-κB) pathway while the selected targets were also implicated in IL-17 signaling pathway, lipid and atherosclerosis. Consequently, adenosine, ginsenoside Rh2, isoliquiritigenin, and licochalcone A were selected to generate the four-compound mixture AGILe and validated for the inhibitory effects on the TNF-α/NF-κB pathway. The results of the present study suggested that the mixture AGILe might be a potential cardioprotective remedy against MI.

Apurinic/apyrimidinic endonuclease 1 regulates palmitic acid-mediated apoptosis in cardiomyocytes via endoplasmic reticulum stress

Cardiomyocyte apoptosis caused by fat metabolism disorder plays an essential role in the pathogenesis of diabetic cardiomyopathy (DCM). Apurinic/apyrimidinic endonuclease 1 (APE1) has multiple functions, including regulating redox and DNA repair. However, the role of APE1 in the pathogenesis of DCM remains unclear. To investigate the mechanism of APE1 on high-fat induced apoptosis in H9C2 cells, we treated H9C2 cells with palmitic acid (PA) as an apoptosis model caused by hyperlipidemia. We found that PA reduced the viability and increased apoptosis of H9C2 cells by inducing up-regulation of APE1 protein and endoplasmic reticulum (ER) stress. APE1 knockdown enhanced PA-induced apoptosis, and ER stress and overexpression of APE1 demonstrated the opposite effect. Furthermore, APE1 regulated PA-induced apoptosis via ER stress. The APE1 mutant (C65A, lack of redox regulation) loses its protective effect against ER stress and apoptosis. These findings indicate that APE1 protects PA-induced H9C2 cardiomyocyte apoptosis through ER stress via its redox-regulated function. This study provided new insights into the therapy for DCM.

Modified Linggui Zhugan Decoction protects against ventricular remodeling through ameliorating mitochondrial damage in post-myocardial infarction rats.

Modified Linggui Zhugan Decoction (MLZD) is a Traditional Chinese Medicine prescription developed from Linggui Zhugan Decoction (LZD) that has been used for the clinical treatment of ischemic cardiovascular diseases. However, the cardioprotective mechanism of MLZD against post-myocardial infarction (MI) ventricular remodeling remains unclear. We explored the effects of MLZD on ventricular remodeling and their underlying mechanisms, respectively, in SD rats with MI models and in H9c2 cardiomyocytes with oxygen-glucose deprivation (OGD) models. The cardiac structure and function of rats were measured by echocardiography, HE staining, and Masson staining. Apoptosis, inflammation, mitochondrial structure and function, and sirtuin 3 (SIRT3) expression were additionally examined. MLZD treatment significantly ameliorated cardiac structure and function, and thus reversed ventricular remodeling, compared with the control. Further research showed that MLZD ameliorated mitochondrial structural disruption, protected against mitochondrial dynamics disorder, restored impaired mitochondrial function, inhibited inflammation, and thus inhibited apoptosis. Moreover, the decreased expression level of SIRT3 was enhanced after MLZD treatment. The protective effects of MLZD on SIRT3 and mitochondria, nevertheless, were blocked by 3-TYP, a selective inhibitor of SIRT3. These findings together revealed that MLZD could improve the ventricular remodeling of MI rats by ameliorating mitochondrial damage and its associated apoptosis, which might exert protective effects by targeting SIRT3.

Cardioprotective effect of crude polysaccharide fermented by Trametes Sanguinea Lyoyd on doxorubicin-induced myocardial injury mice

Doxorubicin (DOX) is a broad-spectrum anti-tumor drug, but its clinical application is greatly limited because of the cardiotoxicity. Thus, exploration of effective therapies against DOX-induced cardiotoxicity is necessary. The aim of this study is to investigate the effects and possible mechanisms of Trametes Sanguinea Lyoyd fermented crude polysaccharide (TSLFACP) against DOX-induced cardiotoxicity. We investigated the protective effects of TSLFACP on myocardial injury and its possible mechanisms using two in vitro cells of DOX-treated cardiomyocytes H9C2 and embryonic myocardial cell line CCC-HEH-2 and a in vivo mouse model of DOX-induced myocardial injury. We found that TSLFACP could reverse DOX-induced toxicity in H9C2 and CCC-HEH-2 cells. Similarly, we found that when pretreatment with TSLFACP (200 mg/kg, i.g.) daily for 6 days, DOX-induced myocardial damage was attenuated, including the decrease in serum myocardial injury index, and the amelioration in cardiac histopathological morphology. Additionally, immunohistochemistry and western blotting were used to identify the underlying and possible signal pathways. We found that TSLFACP attenuated the expression of LC3-II, Beclin-1 and PRAP induced by DOX. In conclusion, our results demonstrated that TSLFACP could protect against DOX-induced cardiotoxicity by inhibiting autophagy and apoptosis.

Isoalantolactone Regulates the Activity of Mitogen-Activated Protein Kinases and Nuclear-Factor Erythroid 2-Related Factor 2 Pathways to Attenue Angiotensin II-Induced Cardiomyocyte Hypertrophy and Oxidative Stress

While isoalantolactone is a sesquiterpene lactone known for its anti-inflammatory and antioxidant activities, its role in cardiac hypertrophy is unknown. This study aimed to explore the role and mechanism of isoalantolactone in cardiomyocyte hypertrophy using angiotensin II-treated H9C2 cells as a model. The Western blot analysis was used to evaluate changes in the cardiac hypertrophy marker proteins atrial natriuretic peptide and brain natriuretic peptide and the activity of nuclear-factor erythroid 2-related factor 2/mitogen-activated protein kinase signaling pathway. Rhodamine-phalloidin staining was used to measure the surface area of cardiomyocytes. Apoptosis and intracellular reactive oxygen species levels were measured by flow cytometry. The results showed that isoalantolactone inhibited angiotensin II-induced H9C2 cell hypertrophy and cardiomyocyte apoptosis and reduced intracellular reactive oxygen species and cytochrome C levels in a dose-dependent manner. Furthermore, isoalantolactone upregulated the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 and inhibited extracellular signal-regulated kinase, c-Jun NH2-terminal kinase, and p38 (a stress-stimulated kinase) activation. Collectively, the findings suggest that isoalantolactone can enhance the antioxidant capacity of H9C2 cells, reduce apoptosis, and inhibit cardiac hypertrophy, and these protective effects may be related to the regulation of nuclear-factor erythroid 2-related factor 2 and mitogen-activated protein kinase pathway activity by isoalantolactone.

MicroRNA-21-3p/Rcan1 signaling axis affects apoptosis of cardiomyocytes of sepsis rats.

Accumulating evidence has reported the role of microRNA-21-3p (miR-21-3p) in sepsis, and our objective was to discuss the effect of the miR-21-3p/regulator of calcineurin 1 (Rcan1) axis on cardiomyocyte apoptosis of septic rats. miR-21-3p and Rcan1 expression in myocardial tissues of lipopolysaccharide (LPS)-treated rats and LPS-treated H9c2 cardiomyocytes was determined. The influences of downregulating miR-21-3p or upregulating Rcan1 in cardiomyocyte apoptosis of LPS-treated rats and LPS-treated H9c2 cardiomyocytes were then evaluated. The target relation between Rcan1 and miR-21-3p was verified. It was observed that miR-21-3p was elevated and Rcan1 was reduced in LPS-treated rats and LPS-treated H9c2 cardiomyocytes. Downregulating miR-21-3p or upregulating Rcan1 could suppress cardiomyocyte apoptosis of LPS-treated rats and LPS-treated H9c2 cardiomyocytes. Based on the dual-luciferase activity assay, miR-21-3p was directly targeted Rcan1 in H9c2 cardiomyocytes. In the rescue experiment, the LPS+miR-21-3p inhibitor+si-Rcan1 group enhanced the apoptosis of H9c2 cardiomyocytes in comparison to the LPS+miR-21-3p inhibitor+si-NC group. Together, our findings identify that the miR-21-3p/Rcan1 axis may affect apoptosis of cardiomyocytes in sepsis, which provides a new idea for understanding the potential mechanism of sepsis.

Mitochondria-targeting EGCG derivatives protect H9c2 cardiomyocytes from H2O2-induced apoptosis: design, synthesis and biological evaluation.

Pathologies related to cardiovascular diseases mostly emerge as a result of oxidative stress buildup in cardiomyocytes. The heavy load of mitochondrial oxidative phosphorylation in cardiac tissues corresponds to a surge in oxidative stress leading to mitochondrial dysfunction and cellular apoptosis. Thus, scavenging the reactive oxygen species (ROS) linked to mitochondria can significantly improve cardio-protection. Epigallocatechin-3-gallate (EGCG), the major polyphenol found in green tea has been extensively studied for its profound health-beneficial activities. Herein, we designed and synthesized a series of mitochondrial-targeting EGCG derivatives, namely MitoEGCGn (n = 4, 6, 8) by incorporating triphenylphosphonium ion onto it using different linkers. MitoEGCGn were found to be non-toxic to H9c2 rat cardiomyocyte cells even at higher doses in comparison to its parent molecule EGCG. Interestingly, MitoEGCG4 and MitoEGCG6 protected the H9c2 cardiomyocyte cells from the oxidative damage induced by H2O2 whereas EGCG was found to be toxic and ineffective in protecting the cells from H2O2 damage. MitoEGCG4 and MitoEGCG6 also protected the cells from the H2O2-induced disruption of mitochondrial membrane potential as well as activation of apoptosis as revealed by pro-caspase 3 expression profile, DNA fragmentation assay, and AO/EtBr staining. Taken together, our study shows that the mitochondria targeting EGCG derivatives were able to effectively combat the H2O2-induced oxidative stress in H9c2 cardiomyocytes. They eventually augmented the mitochondrial health of cardiomyocytes by maintaining the mitochondrial function and attenuating apoptosis. Overall, MitoEGCG4 and MitoEGCG6 could provision a cardioprotective role to H9c2 cardiomyocytes at the time of oxidative insults related to mitochondrial dysfunction-associated injuries.

Protective effect of Guanxin Danshen formula on myocardial ischemiareperfusion injury in rats

Myocardial ischemia/reperfusion injury (MIRI) leads to myocardial tissue necrosis, which will increase the size of myocardial infarction. The study examined the protective effect and mechanism of the Guanxin Danshen formula (GXDSF) on MIRI in rats. MIRI model was performed in rats; rat H9C2 cardiomyocytes were hypoxia-reoxygenated to establish a cell injury model. The GXDSF significantly reduced myocardial ischemia area, reduced myocardial structural injury, decreased the levels of interleukin (IL-1β, IL-6) in serum, decreased the activity of myocardial enzymes, increased the activity of superoxide dismutase (SOD), and reduced glutathione in rats with MIRI. The GXDSF can reduce the expression of nucleotide- binding oligomerization domain, leucine-rich repeat and pyrin domain containing nod-like receptor family protein 3 (NLRP3), IL-1β, caspase-1, and gasdermin D (GSDMD) in myocardial tissue cells. Salvianolic acid B and notoginsenoside R1 protected H9C2 cardiomyocytes from hypoxia and reoxygenation injury and reduced the levels of tumor necrosis factor α (TNF-α) and IL-6 in the cell supernatant, decreasing the NLRP3, IL-18, IL-1β, caspase-1, and GSDMD expression in H9C2 cardiomyocytes. GXDSF can reduce the myocardial infarction area and alleviate the damage to myocardial structure in rats with MIRI, which may be related to the regulation of the NLRP3. GXDSF reduces MIRI in rat myocardial infarction injury, improves structural damage in myocardial ischemia injury, and reduces myocardial tissue inflammation and oxidative stress by lowering inflammatory factors and controlling focal cell death signaling pathways.

The protective effect of thiolutin on doxorubicin-induced H9c2 cardiomyocyte injury.

The use of doxorubicin (DOX) may contribute to cardiotoxicity, limiting its clinical application. Thiolutin (THL) has been found to exert protective roles in various biological activities, while its effects on DOX-induced cardiotoxicity are still uncovered. Cell counting kit 8 assay was utilized to detect cell viability and half maximal inhibitory concentration of THL in H9c2 cardiomyocytes. The level of lactate dehydrogenase (LDH), adenosine triphosphate (ATP), interleukin (IL)-18 and IL-1 beta (IL-1β) were measured using the corresponding detection kits, and flow cytometry determined cell apoptosis rate. The reactive oxygen species (ROS) accumulation was evaluated by utilizing immunofluorescence or flow cytometry assay. The protein levels of NLR family Pyrin domain 3 (NLRP3), pro-Caspase1, cleaved-Caspase1, gasdermin D (GSDMD) and cleaved-GSDMD (GSDMD-N) in H9c2 cells were detected by immunoblotting assay. The treatment of THL reduced H9c2 cell viability in a gradient-dependent manner. THL treatment reversed the DOX-induced inhibition of proliferation, decrease of ATP, up-regulation of LDH, IL-18, IL-1β and production of ROS, activation of NLRP3 and inflammasome-mediated pyroptosis in H9c2 cells. Additionally, NLRP3 knockdown abolished the effects of THL in DOX-treated H9c2 cells remarkably. This investigation proved that THL notably ameliorated DOX-induced apoptosis, oxidative stress, and pyroptosis in H9c2 cardiomyocytes. Besides, THL effectively inactivated DOX-induced NLRP3 inflammasome in H9c2 cells. These findings revealed a promising drug to assist DOX in its anti-cancer effects and protect the heart of patients.

Active-site cysteine 215 sulfonation targets protein tyrosine phosphatase PTP1B for Cullin1 E3 ligase-mediated degradation.

Reactive oxygen species (ROS), released as byproducts of mitochondrial metabolism or as products of NADPH oxidases and other processes, can directly oxidize the active-site cysteine (Cys) residue of protein tyrosine phosphatases (PTPs) in a mammalian cell. Robust degradation of irreversibly oxidized PTPs is essential for preventing accumulation of these permanently inactive enzymes. However, the mechanism underlying the degradation of these proteins was unknown. In this study, we found that the active-site Cys215 of endogenous PTP1B is sulfonated in H9c2 cardiomyocytes under physiological conditions. The sulfonation of Cys215 led PTP1B to exhibit a conformational change, and drive the subsequent ubiquitination and degradation of this protein. We then discovered that Cullin1, an E3 ligase, interacts with the Cys215-sulfonated PTP1B. The functional impairment of Cullin1 prevented PTP1B from oxidation-dependent ubiquitination and degradation in H9c2 cells. Moreover, delivery of the terminally oxidized PTP1B resulted in proteotoxicity-caused injury in the affected cells. In conclusion, we elucidate how sulfonation of the active-site Cys215 can direct turnover of endogenous PTP1B through the engagement of ubiquitin-proteasome system. These data highlight a novel mechanism that maintains PTP homeostasis in cardiomyocytes with constitutive ROS production.

Screening of the most efficacious lactic acid bacteria strain for myocardial infarction recovery and verification and exploration of its functions and mechanisms.

Screening efficient strains by cell platform is cost-effective, but to date, no screening experiments have been performed for targeted lactic acid bacteria with hypoxic/reoxygenation (H/R)-treated cardiomyocytes, and their effects on the phosphoinositide 3-kinase (PI3K)/protein kinase b (Akt)/endothelial nitric oxide synthase (eNOS) pathway in myocardial infarction (MI) are unclear. Here we activated 102 strains of lactic acid bacteria and inoculated them into MRS medium for fermentation. The fermentation supernatants of the lactic acid bacteria were incubated with an H/R model of H9C2 cells. We found that Bifidobacterium longum ZL0210 had the greatest potential for inhibiting the apoptosis of H/R-induced H9C2 cells. Furthermore, it significantly increased the expression of heme oxygenase-1 (HO-1) and quinone oxidoreductase 1 (NQO1) in H9C2 cardiomyocytes, as well as the Bcl-2/Bax protein ratio, protecting damaged myocardial cells via an anti-apoptotic pathway. Intragastric administration of B. longum ZL0210 to mice for one week before and after establishment of an MI model drastically attenuated the myocardial cell hypertrophy and fibrosis of the MI mice. Meanwhile, B. longum ZL0210 significantly reduced the secretion of myocardial enzymes, increased the activity of antioxidant enzymes, and inhibited lipid-oxidative malondialdehyde (MDA) levels. Moreover, it upregulated the expression of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) protein and the phosphorylation levels of PI3K, Akt, and eNOS, resulting in increased NO contents. In summary, we screened 102 strains of lactic acid bacteria with a cell platform and determined that B. longum ZL0210 was a favorable candidate for protecting the myocardium. We are the first to reveal the protective effects of B. longum ZL0210 for MI via activation of the PI3K/Akt/eNOS pathway through TRAIL.

Mangiferin Protects Against Angiotensin-II-Enhanced Hypertrophic Markers and Apoptosis in H9c2 Cardiomyocytes.

Hypertrophic cardiomyopathy accompanies numerous cardiovascular diseases, and the intervention of cardiac hypertrophy is an important issue to prevent detrimental consequences. Mangiferin (MGN) is a glucosylxanthone found in Mangifera indica, which exhibits anti-oxidant and anti-inflammatory properties. Various studies have demonstrated the cardioprotective potential of MGN, but the mechanisms behind its beneficial effects have not been fully revealed. Here, angiotensin-II (Ang-II) was used to induce cardiac hypertrophy, and we examined cell size, expression of hypertrophy markers (e.g., ANP, BNP, and [Formula: see text]-MHC), and oxidative stress (e.g., the ratio of NADPH/NADP[Formula: see text], the expression of p22phox and p67phox, and ROS and SOD production) of cardiomyocytes. Moreover, we assessed the activation of mitogen-activated protein kinase (MAPK) signaling (e.g., p38 and ERK) and the NF-[Formula: see text]Bp65/iNOS axis. Additionally, an annexin V/PI assay was employed to evaluate whether MGN administration can attenuate Ang-II-elicited apoptosis. Lastly, the expression of Ang-II type 1 receptor (AT1) was measured to confirm its involvement in MGN-mediated protection. Our results showed that treatment with MGN attenuated the Ang-II-induced cell size, expression of hypertrophy markers, and oxidative stress in cardiomyocytes. MGN also abrogated the activation of MAPK signaling and the NF-[Formula: see text]Bp65/iNOS axis. Additionally, MGN prevented apoptosis and downregulated the elevation of AT1 in cardiomyocytes that had been exposed to Ang-II. Altogether, these results demonstrated the potential of using MGN to ameliorate the Ang-II-associated cardiac hypertrophy, which may be due to its anti-oxidant and anti-inflammatory effects through suppression of MAPK signaling and the NF-[Formula: see text]Bp65/iNOS axis.

Retracted: Effects of the Wenyang Zhenshuai Granule on the Expression of LncRNA-MiR143HG/miR-143 Regulating ERK5 in H9C2 Cardiomyocytes.

[This retracts the article DOI: 10.1155/2021/6431007.].

Effects of tropomyosin 3 on pyroptosis of cardiomyocytes and fibroblast activation induced by hypoxia/reoxygenation in rats

To explore the role of tropomyosin 3 (TPM3) in hypoxia/reoxygenation (H/R)-induced cardiomyocyte pyroptosis and fibroblast activation. Rat cardiomyocytes (H9c2 cells) were treated with H/R method to simulate myocardial ischemia/reperfusion (I/R) injury, and cell proliferation activity was evaluated with cell counting kit-8 (CCK8). The expression of TPM3 mRNA and protein was detected by quantitative real-time polymerase chain reaction (RT-qPCR) and Western blotting. H9c2 cells with stable TPM3-short hairpin RNA (shRNA) expression were constructed and treated with H/R (hypoxia for 3 hours, and reoxygenation for 4 hours). The expression of TPM3 was measured by RT-qPCR. The expressions of TPM3, pyroptosis-related proteins including caspase-1, NOD-like receptor protein 3 (NLRP3) and Gasdermin family proteins-N (GSDMD-N) were measured by Western blotting. The expression of caspase-1 was also observed by immunofluorescence assay. The levels of human interleukins (IL-1β, IL-18) in the supernatant were determined by enzyme-linked immunosorbent assay (ELISA) to elucidate the effect of sh-TPM3 on pyroptosis of cardiomyocytes. Rat myocardial fibroblasts were incubated with the above cell supernatant, and the expressions of human collagen I, collagen III, matrix metalloproteinase-2 (MMP-2), and matrix metalloproteinase inhibitor 2 (TIMP2) were detected by Western blotting to determine the effect of TPM3-interfered cardiomyocytes on the activation of fibroblasts under H/R conditions. Compared with the control group, H/R treatment for 4 hours significantly decreased the survival rate of H9c2 cells [(25.81±1.90)% vs. (99.40±5.54)%, P < 0.01], promoted the expression of TPM3 mRNA and protein [TPM3/GAPDH (2-ΔΔCt): 3.87±0.50 vs. 1, TPM3/β-Tubulin: 0.45±0.05 vs. 0.14±0.01, both P < 0.01], and promoted the expressions of caspase-1, NLRP3, GSDMD-N, and the enhanced release of cytokines IL-1β and IL-18 [cleaved caspase-1/caspase-1: 0.89±0.04 vs. 0.42±0.03, NLRP3/β-Tubulin: 0.39±0.03 vs. 0.13±0.02, GSDMD-N/β-Tubulin: 0.69±0.05 vs. 0.21±0.02, IL-1β (μg/L): 13.84±1.89 vs. 4.31±0.33, IL-18 (μg/L): 17.56±1.94 vs. 5.36±0.63, all P < 0.01]. However, compared with the H/R group, sh-TPM3 significantly weakened the promoting effects of H/R on these proteins and cytokines [cleaved caspase-1/caspase-1: 0.57±0.05 vs. 0.89±0.04, NLRP3/β-Tubulin: 0.25±0.04 vs. 0.39±0.03, GSDMD-N/β-Tubulin: 0.27±0.03 vs. 0.69±0.05, IL-1β (μg/L): 8.56±1.22 vs. 13.84±1.89, IL-18 (μg/L): 9.34±1.04 vs. 17.56±1.94, all P < 0.01]. In addition, the expressions of collagen I, collagen III, TIMP2, and MMP-2 in myocardial fibroblasts were significantly increased by the cultured supernatants from the H/R group (collagen I/β-Tubulin: 0.62±0.05 vs. 0.09±0.01, collagen III/β-tubulin: 0.44±0.03 vs. 0.08±0.00, TIMP2/β-tubulin: 0.73±0.04 vs. 0.20±0.03, TIMP2/β-Tubulin: 0.74±0.04 vs. 0.17±0.01, all P < 0.01). However, these boosting effects were weakened by sh-TPM3 (collagen I/β-Tubulin: 0.18±0.01 vs. 0.62±0.05, collagen III/β-Tubulin: 0.21±0.03 vs. 0.44±0.03, TIMP2/β-Tubulin: 0.37±0.03 vs. 0.73±0.04, TIMP2/β-Tubulin: 0.45±0.03 vs. 0.74±0.04, all P < 0.01). Interference with TPM3 can alleviate H/R-induced cardiomyocyte pyroptosis and fibroblast activation, suggesting that TPM3 may be a potential target of myocardial I/R injury.