H9c2 Cardiomyoblast Cells Research Articles

17β-Estradiol and/or estrogen receptor alpha blocks isoproterenol-induced calcium accumulation and hypertrophy via GSK3β/PP2A/NFAT3/ANP pathway.

The present study was aimed to investigate the protective effects of 17β-estradiol (E2) and estrogen receptor α (ERα) on isoproterenol (ISO)-treated H9c2 cardiomyoblast cells. In the present study, we treated H9c2 cells with ISO, a β-adrenergic receptor agonist, to induce myocardiac hypertrophy. Pre-administration of E2 or ERα (induced by doxycycline) and E2 plus ERα significantly prevented ISO-induced increase of cell size and cytosolic calcium accumulation, accompanied with increased mRNA of atrial natriuretic peptide and brain natriuretic peptide. However, ICI-ERs antagonist, and melatonin, a specific inhibitor for ERα, reversed the cardioprotective effects, suggesting that E2 action was mediated through ERα. Further evidences showed that E2 and ERα increased the protein level of GSK3β and protein phosphatase 2a inhibitor 2 (I2-PP2A), which subsequently enhanced the activation of I2-PP2A by disrupting PP2A activity and maintains normal calcium outflow. Collectively, E2 and ERα inhibited hypertrophy by preventing cytosol calcium accumulation and by inhibiting the association between PP2A with Na+-Ca2+ exchanger via GSK3β and I2-PP2A activation.

Injectable, cytocompatible, elastic, free radical scavenging and electroconductive hydrogel for cardiac cell encapsulation

The injectable electroconductive hydrogels are desirable for the regenerative therapy of electroresponsive tissues like heart. With the present electroconductive hydrogels, the issues of cytotoxicity, biodegradability, and diffusion of the conductive element and poor water solubility limit their applications. Here, electroconductive injectable single component hydrogels, PANIE-P/PEGDA and PANIS-P/PEGDA, are prepared with fumarate-co-PEG-co-sebacate comacromer conjugated with non-sulfonated/sulfonated polyaniline and PEGDA. These hydrogels have maximum electrical conductivity of 0.351±0.043×10−3Scm−1 and 0.550±0.016×10−3Scm−1, which is comparable to the native myocardium. The hydrogels with 50% comacromer concentration coded as PE50P and PS50P retain 82.48% and 84.08% water on equilibrium swelling respectively. The hydrogels have required a porous surface for cell growth and proliferation. PS50P hydrogel has stiffness of 442kPa with elastic characteristics. The hydrogel is compatible with L929 fibroblast and H9c2 cardiomyoblast cells. PS50P hydrogel has better free radical scavenging property and protective effect over cells under oxidative stress. The hydrogel retains encapsulated cardiomyoblast cells with 98% viability under static long-term in vitro culture. Briefly, the PS50P hydrogel is electroconductive, free radical scavenging and mechanically suitable for cardiac regenerative therapy.

176 Serotonin receptor 2b (5-ht2b) modulates cardiomyocyte proliferation by regulating the hippo pathway

Heart failure is one of the leading causes of death worldwide. In part, this is due to the inadequate regenerative capacity of cardiomyocytes post-injury. Modulation of the Hippo signalling pathway...

Short-Term Hypoxia Reverses Ox-LDL-Induced CD36 and GLUT4 Switching Metabolic Pathways in H9c2 Cardiomyoblast Cells.

High levels of circulating low-density lipoproteins (LDL, plasma proteins that carry cholesterol and triglycerides) are associated with type 2 diabetes, arteriosclerosis, obesity, and hyperlipidemia. In the heart, the accumulation of oxidized low-density lipoprotein (Ox-LDL) has been proposed to play a role in the development of cardiovascular disease. We obtain cholesterol from animals and animal-derived foods such as milk, eggs, and cheese. In previous studies, the ratio of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) was shown to be important for our health. High levels of LDL cholesterol lead to atherosclerosis, increasing the risk of heart attack and ischemic stroke. In this study, we utilized Ox-LDL-treated H9c2 cardiomyoblast cells as a simulated hyperlipidemia model. CD36 metabolism pathway proteins (phospho-Akt, SIRT1, PGC1α, PPARα, CPT1β, and CD36) increased at low doses of Ox-LDL. However, high doses (150 and 200 mg/dL) of Ox-LDL reduced the levels of these proteins. Interestingly, expression of GLUT4 metabolism pathway proteins (phospho-PKCζ) were reduced at low doses, while the expression of phospho-AMPK, phospho-PI3K, phospho-PKCζ, GLUT4, and PDH proteins increased at high doses. Ox-LDL acute treatment induces apoptosis in cardiomyocytes as evidenced by apoptotic nuclei apparition, caspase-3 activation, and cytochrome c release from mitochondria. In our results, Ox-LDL induced lipotoxicity in cardiomyocytes, and subsequent exposure to short-term hypoxia or reversed the Ox-LDL-induced metabolic imbalance. The same result was obtained with the pharmacological activation of SIRT1 by resveratrol and si-PKCζ. The mechanism of metabolic switching during Ox-LDL lipotoxicity seems to be mediated by SIRT1 and PKC ζ. J. Cell. Biochem. 118: 3785-3795, 2017. © 2017 Wiley Periodicals, Inc.

Cobalt chloride induces RhoA/ROCK activation and remodeling effect in H9c2 cardiomyoblasts: Involvement of PI3K/Akt and MAPK pathways

Chronic heart failure is a serious complication of myocardial infarction, one of the major causes of death worldwide that often leads to adverse cardiac hypertrophy and poor prognosis. Hypoxia-induced cardiac tissue remodeling is considered an important underlying etiology. This study aimed to delineate the signaling profiles of RhoA/ROCK, PI3K/Akt, and MAPK and their involvement in regulation of remodeling events in cultured H9c2 cardiomyoblast cells. In addition to its growth-suppressive effect, the hypoxia-mimetic chemical, cobalt chloride (CoCl2) significantly induced RhoA kinase activation as revealed by increased MBS phosphorylation and ROCK1/2 expression in H9c2 cells. CoCl2 treatment up-regulated type I collagen and MMP-9, but did not affect MMP-2, implicating its role in tissue remodeling. Kinetic signal profiling study showed that CoCl2 also elicited Smad2 hyperphosphorylation and its nuclear translocation in the absence of TGF-β1. In addition, CoCl2 activated Akt-, ERK1/2-, JNK-, and p38 MAPK-mediated signaling pathways. Kinase inhibition experiments demonstrated that hydroxyfasudil, a RhoA kinase inhibitor, significantly blocked the CoCl2- and lysophosphatidic acid-evoked Smad2 phosphorylation and overexpression of type I collagen and MMP-9, and that PI3K and ERK interplayed with RhoA and its downstream Smad2 signaling cascade. In conclusion, this study demonstrated that RhoA/ROCK, PI3K/Akt, and MAPK pathways are mechanistically involved in the CoCl2-stimulated tissue remodeling in H9c2 cardiomyoblast cells. Targeting signaling mediators might be used to mitigate hypoxia-related Smad2 phosphorylation and cardiac remodeling events in ischemic cardiomyopathy.

Hispidin induces autophagic and necrotic death in SGC-7901 gastric cancer cells through lysosomal membrane permeabilization by inhibiting tubulin polymerization.

Hispidin and its derivatives are widely distributed in edible mushrooms. Hispidin is more cytotoxic to A549, SCL-1, Bel7402 and Capan-1 cancer cells than to MRC5 normal cells; by contrast, hispidin protects H9c2 cardiomyoblast cells from hydrogen peroxide-induced or doxorubicin-induced apoptosis. Consequently, further research on how hispidin affects normal and cancer cells may help treat cancer and reduce chemotherapy-induced side effects. This study showed that hispidin caused caspase-independent death in SGC-7901 cancer cells but not in GES-1 normal cells. Hispidin-induced increases in LC3-II occurred in SGC-7901 cells in a time independent manner. Cell death can be partially inhibited by treatment with ATG5 siRNA but not by autophagy or necroptosis inhibitors. Ultrastructural evidence indicated that hispidin-induced necrotic cell death involved autophagy. Hispidin-induced lysosomal membrane permeabilization (LMP) related to complex cell death occurred more drastically in SGC-7901 cells than in GES-1 cells. Ca2+ rather than cathepsins from LMP contributed more to cell death. Hispidin induced microtubule depolymerization, which can cause LMP, more drastically in SGC-7901 cells than in GES-1 cells. At 4.1 μM, hispidin promoted cell-free tubulin polymerization but at concentrations higher than 41 μM, hispidin inhibited polymerization. Hispidin did not bind to tubulin. Alterations in microtubule regulatory proteins, such as stathmin phosphorylation at Ser16, contributed to hispidin-induced SGC-7901 cell death. In conclusion, hispidin at concentrations higher than 41 μM may inhibit tubulin polymerization by modulating microtubule regulatory proteins, such as stathmin, causing LMP and complex SGC-7901 cell death. This mechanism suggests a promising novel treatment for human cancer.

Myocardial protection from ischemia/reperfusion injury by exogenous galanin fragment.

Background and purposeGalanin is a multifunctional neuropeptide with pleiotropic roles. The present study was designed to evaluate the potential effects of galanin (2-11) (G1) on functional and metabolic abnormalities in response to myocardial ischemia-reperfusion (I/R) injury.Experimental approachPeptide G1 was synthesized by the 9-fluorenylmethoxycarbonyl (Fmoc)-based solid-phase method. The chemical structure was identified by 1H-NMR spectroscopy and mass spectrometry. Experiments were conducted using a rat model of I/R injury in vivo, isolated perfused rat hearts ex vivo and cultured rat cardiomyoblast H9C2 cells in vitro. Cardiac function, infarct size, myocardial energy metabolism, hemodynamic parameters, plasma levels of creatine kinase-MB (CK-MB) and lactate dehydrogenase (LDH) were measured in order to evaluate the effects of G1 on myocardial I/R injury.Key resultsTreatment with G1 increased cell viability in a dose-dependent manner, inhibited cell apoptosis and excessive mitochondrial reactive oxygen species (ROS) production in response to oxidative stress in H9C2 cells. Pre- or postischemic infusion of G1 enhanced functional and metabolic recovery during reperfusion of the ischemic isolated rat heart. Administration of G1 at the onset of reperfusion significantly reduced infarct size and plasma levels of CK-MB and LDH in rats subjected to myocardial I/R injury.Conclusions and implicationsThese data provide the first evidence for cardioprotective activity of galanin G1 against myocardial I/R injury. Therefore, peptide G1 may represent a promising treatment strategy for ischemic heart disease.

Suppression of isoproterenol-induced apoptosis in H9c2 cardiomyoblast cells by daidzein through activation of Akt.

Increased serum norepinephrine level is one of pathological processes relating to heart disease (HD). Estrogens are considered as potential therapeutics for the treatment of HD; however, estrogen supplementation shows some side-effects, such as increasing the risk of developing breast, endometrial and ovarian cancers. This study investigated the cardio-protective effects of daidzein (Dai), a selective estrogen receptor modulator (SERM) from soy bean extract, in H9c2 cardiomyoblast cells treated with isoproterenol (ISO), a norepinephrine analog. In this in vitro model, H9c2 cells treated with Dai at different concentrations showed no statistical difference in cell viability. TdT-mediated digoxigenin-dUTP nick-end labeling (TUNEL) data and western blotting results indicated that Dai treated-H9c2 cells recovered from the damage induced by ISO. The recovery effects of Dai on ISO-induced damage were blocked by inhibition of Akt activation through adding Akt inhibitor. On the other hand, the fold changes of phosphorylated Akt (p-Akt)/Akt normalized with the control for con, 0.25, 0.5, 1, 3 and 24 h of treatment were 1, 2, 5, 13, 11 and 10, respectively. In conclusion, Dai ameliorates apoptosis of cardiomyoblasts induced by ISO through Akt signaling pathway.

Polyphenol‑rich extract of Aronia melanocarpa inhibits TNF‑α induced apoptosis in H9c2 cells

Introduction. In certain pathological states within cardiovascular system, cardiomyocytes may exhibit overexpression of TNF‑α that results in induction of myocardial oxidative stress and cardiac cells apoptosis. Thus, they may participate in development and progression of post‑infarct congestive heart failure. The aim of this study was to evaluate the effect of polyphenol‑rich Aronia melanocarpa extract (AME) on TNF‑α induced apoptosis in cardiomyoblast H9c2 cells. Material and Methods. Apoptosis was measured in H9c2 cells preincubated with increasing concentrations of commercial extract of aronia – Aronox (10–50 μg/mL) for 24h and then treated with TNF‑α: 100 ng/mL for 24h as well. The MTT assay was used to determine cardiomyoblasts viability. Alteration of the mitochondrial membrane potential, specific for apoptotic cells, was evaluated with caspase-3 activity assay kit. Results. Our results showed that AME significantly inhibited TNF‑α induced apoptosis (IC50 = 55.84 µg/mL) and cytotoxicity in H9c2 cells. Significant inhibition of apoptosis was observed in all tested concentrations of AME. The highest anti‑apoptotic and cytoprotective effect was observed at the highest concentration (50 μg/mL), while in lower the concentrations cytoprotective effect was statistically insignificant. Conclusions. Polyphenol‑rich AME exhibits anti‑apoptotic and cytoprotective effect in H9c2 cardiomyoblasts treated with TNF‑α. Further studies are required in context of its possible application in prevention and/or therapy of cardiovascular diseases.

Regulation of myocardial stromal cell–derived factor 1α/CXCL12 by tumor necrosis factor signaling

BackgroundGlobal myocardial ischemia–reperfusion (I/R) occurs during cardiac operations. This I/R injury leads to increased production of tumor necrosis factor α (TNF) instantly and upregulated expression of stromal cell–derived factor 1 α (SDF-1). On the basis of the published data from our laboratory and other groups, locally produced TNF contributes to cardiac dysfunction mainly via binding to its receptor (tumor necrosis factor receptor 1 [TNFR1]), whereas ischemia-induced myocardial SDF-1 mediates cardioprotection. Although TNF has been shown to work as an upstream initiator for induction of other cytokines and chemokines, there is no information regarding the interaction among TNF, TNFRs, and myocardial SDF-1 expression. In this study, given that TNF downregulated SDF-1 in vascular endothelial cells, we therefore hypothesized that TNF would have a negative effect on myocardial SDF-1 production, which is attributable to TNFR-initiated actions. MethodsUsing a Langendorff model, isolated male mouse hearts were infused with TNF for 45 min. Male adult mouse hearts from wild type, TNFR1 knockout (TNFR1KO), TNFR2KO, and TNFR1/2KO were subjected to global I/R. H9c2 cells with small interfering RNA transfection were used as an in vitro model. The levels of SDF-1 (protein and messenger RNA) were detected by enzyme-linked immunosorbent assay and quantitative reverse transcription–polymerase chain reaction . Protein kinases of IκB (nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor α) and c-jun N-terminal kinase were also determined using Western blot assay. ResultsTNF infusion downregulated myocardial SDF-1 production in a dose-dependent manner in the hearts. In addition, using TNF significantly decreased SDF-1 expression in cardiomyoblasts (H9c2 cells), which was associated with reduced IκB level. Knockdown of TNFR1 or TNFR2 by small interfering RNAs neutralized TNF-suppressed SDF-1 in H9c2 cells. Furthermore, deletion of TNFR1/2 or TNFR2 increased SDF-1 production in the hearts after I/R. ConclusionsOur study represents the initial evidence showing that TNF plays an inhibitory role in modulating myocardial SDF-1 production and blockade of TNF signaling by ablation of TNFR1 and TNFR2 genes increased SDF-1 expression in the heart. These data expand on TNF signaling-initiated mechanisms in myocardium, which may lend a more complete understanding of SDF-1 and TNFR-derived actions in hopes of advancing ischemic heart injury treatments.

Hypoxia Augments Increased HIF-1α and Reduced Survival Protein p-Akt in Gelsolin (GSN)-Dependent Cardiomyoblast Cell Apoptosis.

Cytoskeleton filaments play an important role in cellular functions such as maintaining cell shape, cell motility, intracellular transport, and cell division. Actin-binding proteins (ABPs) have numerous functions including regulation of actin filament nucleation, elongation, severing, capping, cross linking, and actin monomer sequestration. Gelsolin (GSN) is one of the actin-binding proteins. Gelsolin (GSN) is one of the actin-binding proteins that regulate cell morphology, differentiation, movement, and apoptosis. GSN also regulates cell morphology, differentiation, movement, and apoptosis. In this study, we have used H9c2 cardiomyoblast cell and H9c2-GSN stable clones to understand the roles and mechanisms of GSN overexpression in hypoxia-induced cardiomyoblast cell death. The data show that hypoxia or GSN overexpression induces HIF-1α expression and reduces the expression of survival markers p-Akt and Bcl-2 in H9c2 cardiomyoblast cells. Under hypoxic conditions, GSN overexpression further reduces p-Akt expression and elevates total as well as cleaved GSN levels and HIF-1α levels. In addition, GSN overexpression enhances apoptosis in cardiomyoblasts under hypoxia. Hypoxic challenge further induced activated caspase-3 and cell death that was attenuated after GSN knock down, which implies that GSN is a critical therapeutic target against hypoxia-induced cardiomyoblast cell death.

Matricellular protein CCN1 mediates doxorubicin-induced cardiomyopathy in mice

Doxorubicin (DOX) is an effective chemotherapeutic agent however its clinical use is limited by its cumulative cardiotoxicity. Matricellular protein CCN1 mediates work-overload-induced cardiac injury. We aimed to assess the role of CCN1 in DOX-associated cardiomyopathy. Here we discovered CCN1 expression in the myocardium 1 day after DOX treatment (15 mg/kg; i.p.) in mice. Whereas CCN1 synergizes with Fas ligand (FasL) to induce cardiomyocyte apoptosis, we found that FasL was also induced by DOX in the heart. To assess the function of CCN1 in vivo, knockin mice (Ccn1dm/dm) expressing an β6β1-binding defective CCN1 mutant were treated with a single dose of DOX (15 mg/kg; i.p.). Compared with wild-type mice, Ccn1dm/dm mice were resistant to DOX-induced cardiac injury and dysfunction 14 days after injection. Using rat cardiomyoblast H9c2 cells, we demonstrated that DOX induced reactive oxygen species accumulation to upregulate CCN1 and FasL expression. CCN1 mediated DOX cardiotoxicity by engaging integrin β6β1 to promote p38 mitogen-activated protein kinase activation and the release of mitochondrial Smac and HtrA2 to cytosol, thereby counteracting the inhibition of XIAP and facilitating apoptosis. In summary, CCN1 critically mediates DOX-induced cardiotoxicity. Disrupting CCN1/β6β1 engagement abolishes DOX-associated cardiomyopathy in mice.

Palmitic acid interferes with energy metabolism balance by adversely switching the SIRT1-CD36-fatty acid pathway to the PKC zeta-GLUT4-glucose pathway in cardiomyoblasts

Metabolic regulation is inextricably linked with cardiac function. Fatty acid metabolism is a significant mechanism for creating energy for the heart. However, cardiomyocytes are able to switch the fatty acids or glucose, depending on different situations, such as ischemia or anoxia. Lipotoxicity in obesity causes impairments in energy metabolism and apoptosis in cardiomyocytes. We utilized the treatment of H9c2 cardiomyoblast cells palmitic acid (PA) as a model for hyperlipidemia to investigate the signaling mechanisms involved in these processes. Our results show PA induces time- and dose-dependent lipotoxicity in H9c2 cells. Moreover, PA enhances cluster of differentiation 36 (CD36) and reduces glucose transporter type 4 (GLUT4) pathway protein levels following a short period of treatment, but cells switch from CD36 back to the GLUT4 pathway after during long-term exposure to PA. As sirtuin 1 (SIRT1) and protein kinase Cζ (PKCζ) play important roles in CD36 and GLUT4 translocation, we used the SIRT1 activator resveratrol and si-PKCζ to identify the switches in metabolism. Although PA reduced CD36 and increased GLUT4 metabolic pathway proteins, when we pretreated cells with resveratrol to activate SIRT1 or transfected si-PKCζ, both were able to significantly increase CD36 metabolic pathway proteins and reduce GLUT4 pathway proteins. High-fat diets affect energy metabolism pathways in both normal and aging rats and involve switching the energy source from the CD36 pathway to GLUT4. In conclusion, PA and high-fat diets cause lipotoxicity in vivo and in vitro and adversely switch the energy source from the CD36 pathway to the GLUT4 pathway.

Characterization of cytoprotective and toxic properties of iron chelator SIH, prochelator BSIH and their degradation products.

Free cellular iron catalyzes the formation of toxic hydroxyl radicals and therefore chelation of iron could be a promising therapeutic approach in pathological states associated with oxidative stress. Salicylaldehyde isonicotinoyl hydrazone (SIH) is a strong intracellular iron chelator with well documented potential to protect against oxidative damage both in vitro and in vivo. Due to the short biological half-life of SIH and risk of toxicity due to iron depletion, boronate prochelator BSIH has been designed. BSIH cannot bind iron until it is activated by certain reactive oxygen species to active chelator SIH. The aim of this study was to examine the toxicity and cytoprotective potential of BSIH, SIH, and their decomposition products against hydrogen peroxide-induced injury of H9c2 cardiomyoblast cells. Using HPLC, we observed that salicylaldehyde was the main decomposition products of SIH and BSIH, although a small amount of salicylic acid was also detected. In the case of BSIH, the concentration of formed salicylaldehyde consistently exceeded that of SIH. Isoniazid and salicylic acid were not toxic nor did they provide any antioxidant protective effect in H9c2 cells. In contrast, salicylaldehyde was able to chelate intracellular iron and significantly preserve cellular viability and mitochondrial inner membrane potential induced by hydrogen peroxide. However it was consistently less effective than SIH. The inherent toxicities of salicylaldehyde and SIH were similar. Hence, although SIH - the active chelating agent formed following the BSIH activation - undergoes rapid hydrolysis, its principal decomposition product salicylaldehyde accounts markedly for both cytoprotective and toxic properties.

Gypenosides alleviate myocardial ischemia-reperfusion injury via attenuation of oxidative stress and preservation of mitochondrial function in rat heart.

Gypenosides (GP) are the predominant components of Gynostemma pentaphyllum, a Chinese herb medicine that has been widely used for the treatment of chronic inflammation, hyperlipidemia, and cardiovascular disease. GP has been demonstrated to exert protective effects on the liver and brain against ischemia-reperfusion (I/R) injury, yet whether it is beneficial to the heart during myocardial I/R is unclear. In this study, we demonstrate that pre-treatment with GP dose-dependently limits infarct size, alleviates I/R-induced pathological changes in the myocardium, and preserves left ventricular function in a rat model of cardiac I/R injury. In addition, GP pre-treatment reduces oxidative stress and protects the intracellular antioxidant machinery in the myocardium. Further, we show that the cardioprotective effect of GP is associated with the preservation of mitochondrial function in the cardiomyocytes, as indicated by ATP level, enzymatic activities of complex I, II, and IV on the mitochondrial respiration chain, and the activity of citrate synthase in the citric acid cycle for energy generation. Moreover, GP maintains mitochondrial membrane integrity and inhibits the release of cytochrome c from the mitochondria to the cytosol. The cytoprotective effect of GP is further confirmed in vitro in H9c2 cardiomyoblast cell line with oxygen-glucose deprivation and reperfusion (OGD/R), and the results indicate that GP protects cell viability, reduces oxidative stress, and preserves mitochondrial function. In conclusion, our study suggests that GP may be of clinical value in cytoprotection during acute myocardial infarction and reperfusion.

Steroidal Saponin Diosgenin from Dioscorea bulbifera Protects Cardiac Cells from Hypoxia-reoxygenation Injury Through Modulation of Pro-survival and Pro-death Molecules.

Background:Diosgenin, a steroidal saponin from plants, exhibits many biological potentials. Herein, the cardioprotective role of diosgenin is studied.Materials and Methods:The effect of diosgenin, isolated from Dioscorea bulbifera, was studied on hypoxia-reoxygenation (HR) in H9c2 cardiomyoblast cells. The amount of diosgenin in the plant extract was analyzed by high-performance thin layer chromatography using a solvent system comprising of chloroform:methanol:acetic acid:formic acid (13:4.5:1.5:1). Cardioprotection was checked by (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Further, the release of lactate dehydrogenase, an enzyme released during cell death was checked. The proteins responsible for cell death (Bax) and cell survival (Bcl-2, hemeoxygenase-1 and Akt) were analyzed using Western blot to check the cardioprotective role of diosgenin.Conclusion:Supplementation of diosgenin mitigates HR injury, thereby exhibiting cardioprotective potential.SUMMARY The cardioprotective effect of Diosgenin was evidenced from the improved cell survival after hypoxia-reoxygenation injury demonstrated through MTT cell survival assay.The release of lactate dehydrogenase, an enzyme released during cell death was decreased by Diosgenin.Diosgenin upregulated the pro-survival molecules like B-cell lymphoma 2 (Bcl-2), heme oxygenase-1 and the phosphorylation of ATK (at serine 473); and at the same time pro-.death molecules like Bax was downregulated.Thus, Diosgenin as a plant based steroidal saponin is confirmed to mitigate ischemic reperfusion injury. Figure

FGF-2 Transcriptionally Down-Regulates the Expression of BNIP3L via PI3K/Akt/FoxO3a Signaling and Inhibits Necrosis and Mitochondrial Dysfunction Induced by High Concentrations of Hydrogen Peroxide in H9c2 Cells

Background/Aims: Cardiovascular disease is a growing major global public health problem. Necrosis is one of the main forms of cardiomyocyte death in heart disease. Oxidative stress is regarded as one of the key regulators of cardiac necrosis, which eventually leads to cardiovascular disease. Many pharmacological and in vitro studies have suggested that FGF-2 can act directly on cardiomyocytes to maintain the integrity and function of the myocardium and prevent damage during oxidative stress. However, the mechanisms by which FGF-2 rescues the myocardium from oxidative stress damage in cardiovascular disease remain unclear. The present study explored the protective effects of FGF-2 in the H₂O₂-induced necrosis of H9C2 cardiomyocytes as well as the possible signaling pathways involved. Methods: Necrosis of H9c2 cardiomyocytes was induced by H₂O₂ and assessed using a Cell Counting Kit-8 (CCK8) assay and flow cytometry analysis. The cells were pretreated with the PI3K/Akt inhibitor Wortmannin to investigate the possible involvement of the PI3K/Akt pathway in the protection by FGF-2. The levels of Akt, p-Akt, FoxO3a, p-FoxO3a, and BNIP3L were detected by Western blot. Chromatin immuno-precipitation (ChIP) analysis was used to test whether FoxO3a binds directly to the BNIP3L promoter region. A luciferase assay was used to study the effects of FoxO3a on BNIP3L gene promoter activity. Mitochondrial ΔΨM was quantified using tetramethylrhodamine methyl ester perchlorate (TMRM). The mitochondrial oxygen consumption rate (OCR) was assessed with a Seahorse XF24 Analyzer. Results: Treatment with H₂O₂ decreased the phosphorylation of Akt and FoxO3a, and it induced the nuclear localization of FoxO3a and the necrosis of H9c2 cells. These effects of H₂O₂ were abrogated by pretreatment with FGF-2. Furthermore, the protective effects of FGF-2 were abolished by the PI3K/Akt inhibitor Wortmannin. ChIP analyses indicated that FoxO3a binds directly to the BNIP3L promoter region. Using a luciferase assay, we further observed that FoxO3a increased BNIP3L gene promoter activity. As expected, overexpression of BNIP3L in H9C2 cardiomyoblast cells reduced the cardioprotection of FGF-2 in H₂O₂-induced necrosis and mitochondrial dysfunction. Conclusions: The present data suggest that FGF-2 protects against H₂O₂-induced necrosis of H9C2 cardiomyocytes via the activation of the PI3K/Akt/FoxO3a pathway. Moreover, the present results demonstrate that FoxO3a is an important transcription factor that acts by binding to the promoter and promoting the transcription of BNIP3L, and it contributes to the necrosis and mitochondrial dysfunction induced by H₂O₂ in H9c2 cardiomyoblast cells.

Catha edulis Extract Induces H9c2 Cell Apoptosis by Increasing Reactive Oxygen Species Generation and Activation of Mitochondrial Proteins.

Background:Catha edulis (Khat) is an evergreen shrub or small tree, traditionally used by various peoples of the Arabian Peninsula and Africa as an integral component of the socioeconomic traditions. It is believed that the psychostimulant nature and toxic nature of khat is primarily due to the presence of cathinone and cathine respectively. Studies have shown that khat chewing is closely associated with cardiac complications, especially myocardial infarction. Hence in this study, we exposed cathine-rich khat extract in a cardiomyoblast H9c2 (2-1) cell line to check the cell death mechanism.Materials and Methods:Extraction of Catha edulis leaves was done and the presence of cathine was confirmed with LC-MS-MS. The anti-proliferative activity was assayed using MTT and apoptosis detection by acridine orange/propidium iodide assay. The expression of Bcl-2 and Bax protein and caspase-3/7 expression were analyzed. The level of reactive oxygen species generation was also evaluated.Results:The khat extract showed an IC50 value of 86.5 μg/ml at 48 hours treatment. We have observed significant early apoptosis events by intervened acridine orange within the fragmented DNA with bright green fluorescence upon treatment. The Bcl-2 expression in the treatment with IC50 concentration of khat extract for 24, 48 and 72 hours of incubation significantly decreased with increase in bax level. The increased activation of caspase-3/7 was significantly observed upon treatment together with significant increase of ROS was detected at 24 and 48 hours treatment.Conclusion:Collectively, our results provide insight into the mechanisms by which Catha edulis leaves mediate cell death in cardiomyocytes.SUMMARY Catha edulis (Khat) is an evergreen psychotropic shrub or small treeExtraction of khat leaves was done and the presence of cathine was confirmed with liquid chromatography-mass spectrometry-mass spectrometryThe khat extract showed an IC50 value of 86.5 μg/ml at 48 h treatment in H9c2 (2–1) cell lineThe observed cell death was associated with increased expression of Bcl2 and caspase-3Significant increase of reactive oxygen species was also detected in the cell with treatment. Abbreviations used: CNS: central nervous system; AMI: acute myocardial infarction; TLC: thin layer chromatography; ESI: electrospray ionization; FBS: fetal bovine serum; DMSO: dimethylsulfoxide; AO; acridine orange; PI; propidium iodide; HRP: horseradish peroxidase; HBSS: hank's balanced salt solution; DCFH-DA: 2’,7’-dichlorofluorescin diacetate; NAC, 10 mM: NAC: N-acetyl cysteine; ROS: reactive oxygen species.

Gold nanoparticle loaded porcine cholecystic-extracellular matrix: A potential bioscaffold for cardiac tissue engineering.

Event Abstract Back to Event Gold nanoparticle loaded porcine cholecystic-extracellular matrix: A potential bioscaffold for cardiac tissue engineering. Reshma S. Nair1 and Anilkumar TV1 1 Sree Chitra Tirunal Institute for Medical Sciences and Technology, Division of Experimental Pathology, India Introduction: Porcine Cholecystic Extracellular matrix (C-ECM) has been found as a potential scaffold for tissue engineering applications. Its ability to induce faster healing[1] by promoting pro-regenerative tissue response[2] has been demonstrated in animal models. However, its potential as a scaffold for cardiac tissue engineering has not been studied. It has been hypothesised that the addition of gold nanoparticles (AuNP) modulates the quality of extracellular matrix (ECM) used for tissue engineering application. The objective of this study is to fabricate a bionanocomposite scaffold by coating AuNP over cholecystic ECM (C-ECM) for growth and differentiation of cardiogenic stem cells. Materials And Methods: C-ECM[3] were prepared as reported previously. Chloroauric acid was purchased from Sigma Aldrich. H9c2 cardiomyoblast cell line received from National Centre for Cell Science, Pune, DMEM with high glucose with 10% FBS were used, MTT. Synthesis of AuNPs of 20 nm was carried out according to the procedures described by Turkevich et al[4]. The purification of the synthesized AuNPs were carried out by centrifugation at 7000 rpm for 15 minutes. The pellet was suspended in distilled water and stored in dark at 4°C till the red colour is retained. Amine functionalization of AuNP was done by coating with L-cysteine to promote covalent bonding to the C-ECM scaffold. 1-Ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) and N-hydroxysuccinimide (NHS), were added for aiding covalent binding between amine functionalized AuNPs and the activated carboxylic groups of the C-ECM. The bionanocomposite scaffold was characterized via Scanning electron microscopy, Fourier transform infrared spectroscopy, Uniaxial tensile testing, and Differential scanning calorimetry. Electrical conductivity was measured to check the suitability of the bionanocomposite scaffold in cardiac tissue engineering. Cardiomyoblast cells were seeded onto the scaffold to analyse the cell seeding efficiency of the material. MTT assay was performed and the cell seeding efficiency was calculated after three days of culture. The potential of the tissue construct as a bioartificial cardiac patch was then evaluated. Results And Discussion: Particle size of the AuNP was 20nm size (Fig 1) confirmed by UV- VIS Spectrophotometry. Functionalization of the gold nanoparticle on the biocomposite was achieved. Successful binding of amine functionalized gold nanoparticle on C-ECM scaffold was also practical. The composite bioscaffold did not cause cytotoxicity as revealed by results of MTT-assay on H9c2 cells (Fig2). Conclusion: This combination of bionanocomposite scaffold supported the growth of cardiomyoblast cells. The tissue construct is a potential cardiac patch for repairing tissue loss due to myocardial infarction. DST- INSPIRE Fellowship grant; Director, Sree Chitra Tirunal Institute for Medical Sciences and Technology; Meat Products of India

Follistatin-like 1 protects cardiomyoblasts from injury induced by sodium nitroprusside through modulating Akt and Smad1/5/9 signaling

Cardiac cell apoptosis provoked by excessive sodium nitroprusside (SNP) toxicity, a potent vasodilator, limited its clinical application. Effective means for protection against SNP-induced cardiotoxicity would be highly needed. This study investigated the effects of Follistatin-like 1 (FSTL1) on the injury induced by SNP in rat cardiomyoblast H9c2 cells. First, expression of FSTL is attenuated following SNP treatment. SNP challenge significantly increases cardiac cell death, which is attenuated by FSTL1 pretreatment. Additionally, knockdown of endogenous FSTL1 enhances SNP-induced cell apoptosis. Furthermore, FSTL1 pretreatment partially inhibits SNP-induced NO generation. LY294002 and BMP4 completely abolish cytoprotective role of FSTL1 against SNP challenge, indicating both activation of Akt and inhibition of BMP/Smad1/5/9 signaling are involved in this cellular process. Lastly, FSTL1-mediated cytoprotection is independent of Smad2/3 signaling, as SB525334 fails to remove its protective role. Taken together, these results indicated that FSTL1 protects the SNP-induced injury in cardiac H9c2 cells through, at least in part, the activation of Akt and inhibition of Smad1/5/9 signaling.