scholarly journals Implication of CREB in the calcium regulation by ischemia/reperfusion in cardiomyocytes

2021 ◽  
Vol 154 (9) ◽  
Author(s):  
Débora Falcón ◽  
Isabel Mayoral ◽  
Antonio Ordóñez ◽  
Tarik Smani
Keyword(s):  
Transcription Factor ◽  
Protein Expression ◽  
Molecular Mechanisms ◽  
Ventricular Myocytes ◽  
Heart Diseases ◽  
Ischemia Reperfusion ◽  
Neonatal Rat ◽  
Rat Cardiomyocytes ◽  
Expression Of Genes ◽  
Transcription Factor Activation

It is well established that abnormalities in [Ca2+] regulation occur in heart diseases. Actually, independent studies demonstrated that Orai1/2/3 and TRPC protein related with store-operated calcium channels (SOCC) have a role in cardiac pathologies. Ischemia/reperfusion (I/R) stimulates transcription factor activation that modifies the expression of genes implicated in the pathogenesis of this process. Previous results described an increase in the expression of Orai1 and TRPC5 in cardiomyocytes after I/R, although the molecular mechanisms that mediate this regulation are still unknown. The aim of this study is to examine the molecular mechanisms implicated in the regulation of SOCC in cardiomyocytes after I/R focusing on the handling of intracellular [Ca2+]. Experiments were performed in a rat model of myocardial I/R, in adult (ARVM) and neonatal rat ventricular myocytes (NRVM), and in ventricular samples of heart-failure patients. Immunofluorescence was used to investigate CREB activation, and the protein expression was analyzed by Western blot. Calcium diastolic studies were realized using microfluorimetric technic with FURA-2AM. To evoke intracellular Ca2+ transients, ARVMs were field stimulated at 0.5 Hz and NRVMs at 1 Hz. An activation of CREB after I/R was observed in adult and neonatal rat cardiomyocytes. Furthermore, it was demonstrated that this activation was mediated by PKA, but not for EPAC2 or ERK. I/R induced an CREB-dependent ORAI protein expression increase and also an increase in the diastolic calcium in NRVM and ARVM from I/R animal models. Additionally, it was observed that ORAI1 inhibition with SYNTA-66 or GSK reduced the calcium diastolic increase induced by I/R. We demonstrated, for the first time, the activation of the transcription factor CREB in cardiomyocytes after I/R. This activation induces an up-regulation of ORAI1, suggesting that this channel plays a role in the I/R induced calcium diastolic increase.

mTOR signaling-related microRNAs as cardiac hypertrophy modulators in high‐volume endurance training

2021 ◽  
Author(s):  
Bruno R.A. Pelozin ◽  
Ursula Paula Reno Soci ◽  
João L. P. Gomes ◽  
Edilamar Menezes Oliveira ◽  
Tiago Fernandes
Keyword(s):  
Protein Expression ◽  
Molecular Mechanisms ◽  
High Volume ◽  
Left Ventricular ◽  
Mtor Signaling ◽  
Neonatal Rat ◽  
Cardiomyocyte Hypertrophy ◽  
Peak Exercise ◽  
Dependent Manner ◽  
Rat Cardiomyocytes

Aerobic exercise training (ET) promotes cardiovascular adaptations, including physiological left ventricular hypertrophy (LVH). However, the molecular mechanisms that underlying these changes are unclear. The study aimed to elucidate specific miRNAs and target genes involved with the Akt/mTOR signaling in high-volume ET-induced LVH. Eight-week-old female Wistar rats were assigned to three groups: sedentary control (SC), trained protocol 1 (P1), and trained protocol 2 (P2). P1 consisted of 60 minutes/day of swimming, 5x/week, for 10 weeks. P2 consisted of the same protocol as P1 until the 8th week; in the 9th week, rats trained 2x/day, and in the 10th week, trained 3x/day. Subsequently, structure and molecular parameters were evaluated in the heart. Trained groups demonstrate higher values to VO2 peak, exercise tolerance, and LVH in a volume-dependent manner. The miRNA-26a-5p levels were higher in P1 and P2 compared to SC group (150±15%, d=1.8; 148±16%, d=1.7; and 100±7%, respectively, P < 0.05). In contrast, miRNA-16-5p levels were lower in P1 and P2 compared to SC group (69±5%, d=2.3, P < 0.01; 37±4%, d=5.6, P < 0.001 and 100±6%, respectively). Additionally, miRNA-16-5p knockdown and miRNA-26a-5p overexpression significantly promoted cardiomyocyte hypertrophy in neonatal rat cardiomyocytes. Both miRNAs were selected, using Diana Tolls bioinformatics website, for acting in the mTOR signaling pathway. The protein expression of Akt, mTOR, p70S6k, and 4E-BP1 were greater in P1 and even more pronounced in P2. Nonetheless, GSK3β protein expression was lower in trained groups. Together, these molecular changes may contribute to a pronounced physiological LVH observed in high-volume aerobic training.

scholarly journals PGC-1α Participates in the Protective Effect of Chronic Intermittent Hypobaric Hypoxia on Cardiomyocytes

2018 ◽  
Vol 50 (5) ◽  
pp. 1891-1902 ◽  
Author(s):  
Shuo Gu ◽  
Hong Hua ◽  
Xinqi Guo ◽  
Zhanfeng Jia ◽  
Yi Zhang ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Protein Expression ◽  
Protein Level ◽  
Hypobaric Hypoxia ◽  
Molecular Mechanisms ◽  
Ventricular Myocytes ◽  
Ischemia Reperfusion ◽  
Sprague Dawley ◽  
Knock Down ◽  
Intermittent Hypobaric Hypoxia

Background/Aims: Myocardial ischemia/reperfusion (I/R) or hypoxia/reoxygenation (H/R) injury is always characterized by Ca2+ overload, energy metabolism disorder and necrocytosis of cardiomyocytes. We showed previously that chronic intermittent hypobaric hypoxia (CIHH) improves cardiac function during I/R through improving cardiac glucose metabolism. However, the underlying cellular and molecular mechanisms of CIHH treatment improving energy metabolism in cardiomyocytes are still unclear. In this study, we determined whether and how CIHH protects cardiomyocytes from Ca2+ overload and necrocytosis through energy regulating pathway. Methods: Adult male Sprague-Dawley rats were randomly divided into two groups: control (CON) and CIHH group. CIHH rats received a hypobaric hypoxia simulating 5,000-m altitude for 28 days, 6 hours each day, in hypobaric chamber. Rat ventricular myocytes were obtained by enzymatic dissociation. The intracellular calcium concentration ([Ca2+]i) and cTnI protein expression were used to evaluate the degree of cardiomyocytes injury during and after H/R. The mRNA and protein expressions involved in cardiac energy metabolism were determined using quantitative PCR and Western blot techniques. PGC-1α siRNA adenovirus transfection was used to knock down PGC-1α gene expression of cardiomyocytes to determine the effect of PGC-1α in the energy regulating pathway. Results: H/R increased [Ca2+]i and cTnI protein expression in cardiomyocytes. CIHH treatment decreased [Ca2+]i (p< 0.01) and cTnI protein expression (p< 0.01) in cardiomyocytes after H/R. Both mRNA and protein expression of PGC-1α increased after CIHH treatment, which was reversed by PGC-1α siRNA adenovirus transfection. Furthermore, CIHH treatment increased the expression of HIF-1α, AMPK and p-AMPK in cardiomyocytes, and pretreatment with AMPK inhibitor dorsomorphin abolished the enhancement of PGC-1α protein expression in cardiomyocytes by CIHH (p< 0.01). In addition, PGC-1α knock down also abolished the increased protein level of GLUT4 (p< 0.01) and decreased the protein level of CPT-1b (p< 0.05) in cardiomyocytes by CIHH treatment. Conclusion: CIHH treatment could reduce the calcium overload and H/R injury in cardiomyocytes by up-regulating the expression of PGC-1α and regulating the energy metabolism of glucose and lipid. The HIF-1α-AMPK signaling pathway might be involved in the process.

scholarly journals Dexmedetomidine Protects Cardiomyocytes against Hypoxia/Reoxygenation Injury by Suppressing TLR4-MyD88-NF-κB Signaling

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Jin-meng Gao ◽  
Xiao-wen Meng ◽  
Juan Zhang ◽  
Wei-rong Chen ◽  
Fan Xia ◽  
...  
Keyword(s):  
Protein Expression ◽  
Ischemia Reperfusion Injury ◽  
Cell Damage ◽  
Ischemia Reperfusion ◽  
Neonatal Rat ◽  
Mrna Levels ◽  
Rat Cardiomyocytes ◽  
Knock Down ◽  
Ldh Activity ◽  
Hypoxia Reoxygenation

Objective. We previously reported that dexmedetomidine (DEX) offers cardioprotection against ischemia/reperfusion injury in rats. Here, we evaluated the role of toll-like receptors 4- (TLR4-) myeloid differentiation primary response 88- (MyD88-) nuclear factor-kappa B (NF-κB) signaling in DEX-mediated protection of cardiomyocytes usingin vitromodels of hypoxia/reoxygenation (H/R).Methods. The experiments were carried out in H9C2 cells and in primary neonatal rat cardiomyocytes. Cells pretreated with vehicle or DEX were exposed to hypoxia for 1 h followed by reoxygenation for 12 h. We analyzed cell viability and lactate dehydrogenase (LDH) activity and measured tumor necrosis factor-α(TNF-α), interleukin-6 (IL-6), and IL-1βmRNA levels, TLR4, MyD88, and nuclear NF-κB p65 protein expression and NF-κB p65 nuclear localization. TLR4 knock-down by TLR4 siRNA transfection and overexpression by TLR4 DNA transfection were used to further confirm our findings.Results. DEX protected against H/R-induced cell damage and inflammation, as evidenced by increased cell survival rates, decreased LDH activity, and decreased TNF-α, IL-6, and IL-1βmRNA levels, as well as TLR4 and NF-κB protein expression. TLR4 knock-down partially prevented cell damage following H/R injury, while overexpression of TLR4 abolished the DEX-mediated protective effects.Conclusions. DEX pretreatment protects rat cardiomyocytes against H/R injury. This effect is partly mediated by TLR4 suppression via TLR4-MyD88-NF-κB signaling.

Abstract 1778: Estrogen Protects Cardiomyocytes from Apoptosis by Suppressing p38alpha-mediated p53 activation and by Downregulating a Negative Feedback from p53 on p38beta

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Han Liu ◽  
Ali Pedram ◽  
Ellis R Levin ◽  
Jin K Kim
Keyword(s):  
Molecular Mechanisms ◽  
Ischemia Reperfusion ◽  
Fluorescent Microscopy ◽  
Annexin V ◽  
Neonatal Rat ◽  
Rat Cardiomyocytes ◽  
Downstream Target ◽  
Whole Cell Lysate ◽  
P53 Activation

To investigate the molecular mechanisms of estrogen-mediated protection of cardiomyocytes in hypoxic stress. Estrogen is anti-apoptotic and promotes survival of cardiomyocytes under ischemia-related stress. We have previously shown that estrogen protects cardiomyocytes exposed to simulated ischemia-reperfusion (I/R) by differentially regulating pro-apoptotic p38alpha and pro-survival p38beta. However, little is known about how E2 modulation of the kinases alters the apoptotic signaling in cardiomyocytes. An attractive downstream target is p53, a well-known mediator of apoptosis and a substrate of p38alpha. We propose that the cytoprotective actions of estrogen involve regulation of p53 via p38. Cultured neonatal rat cardiomyocytes underwent hypoxia followed by reoxygenation (H/R) to simulate I/R. The extent of apoptosis was determined by examining annexin V-positive cells under fluorescent microscopy. The whole cell lysate was collected after H/R, and the protein of interest was immunoprecipitated and immunoblotted. The p38 activity was determined by immunoprecipitating the protein and performing in-vitro kinase assays on the substrate, ATF2. In our model, p53 played a significant role in H/R-induced myocyte death: Inhibition of p53 (by pifithrin-alpha or by siRNA) significantly reduced the number of apoptotic cells by half. Phosphorylation of p53 (p-p53) at serine 15 increased after H/R, while E2 effectively inhibited this form of p53 activation. Use of a specific agonist for each estrogen receptor isoform (ERalpha or ERbeta) demonstrated that both isoforms participate in inhibition of p-p53. E2 attenuated transcription of apoptosis-specific targets of p53, puma and noxa , as determined by RT PCR. In addition, inhibition of p53 augmented the p38beta activity, suggesting a baseline repression of this pro-survival kinase by p53 that may be reversed by E2. Our results demonstrate that during H/R stress, cardiomyocytes undergo p53-dependent apoptosis following phosphorylation of p53 by p38alpha. E2 protects cardiomyocytes by inhibiting p38alpha-p53 signaling, leading to pro-survival p38beta activation.

scholarly journals Downregulation of LAPTM4B Contributes to the Impairment of the Autophagic Flux via Unopposed Activation of mTORC1 Signaling During Myocardial Ischemia/Reperfusion Injury

2020 ◽  
Vol 127 (7) ◽  
Author(s):  
Shanshan Gu ◽  
Jiliang Tan ◽  
Qiang Li ◽  
Shenyan Liu ◽  
Jian Ma ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Transmembrane Protein ◽  
Ischemia Reperfusion ◽  
Neonatal Rat ◽  
Autophagic Flux ◽  
Rat Cardiomyocytes ◽  
Neonatal Rat Cardiomyocytes ◽  
Mtorc1 Signaling ◽  
Hypoxia Reoxygenation

Rationale: Impaired autophagic flux contributes to ischemia/reperfusion (I/R)-induced cardiomyocyte death, but the underlying molecular mechanisms remain largely unexplored. Objective: To determine the role of LAPTM4B (lysosomal-associated transmembrane protein 4B) in the regulation of autophagic flux and myocardial I/R injury. Methods and Results: LAPTM4B was expressed in murine hearts but downregulated in hearts with I/R (30 minutes/2 hours) injury and neonatal rat cardiomyocytes with hypoxia/reoxygenation (6 hours/2 hours) injury. During myocardial reperfusion, LAPTM4B-knockout (LAPTM4B −/− ) mice had a significantly increased infarct size and lactate dehydrogenase release, whereas adenovirus-mediated LAPTM4B-overexpression was cardioprotective. Concomitantly, LAPTM4B −/− mice showed higher accumulation of the autophagy markers LC3-II (microtubule-associated protein 1A/1B-light chain 3), but not P62, in the I/R heart, whereas they did not alter chloroquine-induced further increases of LC3-II and P62 in both sham and I/R hearts. Conversely, LAPTM4B-overexpression had opposite effects. The hypoxia/reoxygenation–reduced viability of neonatal rat cardiomyocytes, ratio of autolysosomes/autophagosomes, and function of lysosomes were further decreased by LAPTM4B-knockdown but reversed by LAPTM4B-overexpression. Moreover, the LAPTM4B-overexpression–mediated benefits were abolished by knockdown of lysosome-associated membrane protein-2 (an autophagosome-lysosome fusion protein) in vivo and by the autophagy inhibitor bafilomycin A1 in vivo. In contrast, rapamycin (Rapa) successfully restored the impaired autophagic flux in LAPTM4B −/− mice and the subsequent myocardial I/R injury. Mechanistically, LAPTM4B regulated the activity of mTORC1 (mammalian target of rapamycin complex 1) via interacting with mTOR through its EC3 (extracelluar) domain. Thus, mTORC1 was overactivated in LAPTM4B −/− mice, leading to the repression of TFEB (transcription factor EB), a master regulator of lysosomal and autophagic genes, during myocardial I/R. The mTORC1 inhibition or TFEB-overexpression rescued the LAPTM4B −/− -induced impairment in autophagic flux and I/R injury, whereas TFEB-knockdown abolished the LAPTM4B-overexpression–mediated recovery of autophagic flux and cardioprotection. Conclusions: The downregulation of LAPTM4B contributes to myocardial I/R–induced impairment of autophagic flux via modulation of the mTORC1/TFEB pathway. Graphic Abstract: A graphic abstract is available for this article.

scholarly journals Neuregulin-1β promotes glucose uptake via PI3K/Akt in neonatal rat cardiomyocytes

2016 ◽  
Vol 310 (9) ◽  
pp. E782-E794 ◽  
Author(s):  
Laura Pentassuglia ◽  
Philippe Heim ◽  
Sonia Lebboukh ◽  
Christian Morandi ◽  
Lifen Xu ◽  
...  
Keyword(s):  
Heart Failure ◽  
Glucose Uptake ◽  
Molecular Mechanisms ◽  
Ventricular Myocytes ◽  
Cardiac Development ◽  
Cardiac Cells ◽  
Neonatal Rat ◽  
Akt Inhibitor ◽  
Protective Function ◽  
Rat Cardiomyocytes

Nrg1β is critically involved in cardiac development and also maintains function of the adult heart. Studies conducted in animal models showed that it improves cardiac performance under a range of pathological conditions, which led to its introduction in clinical trials to treat heart failure. Recent work also implicated Nrg1β in the regenerative potential of neonatal and adult hearts. The molecular mechanisms whereby Nrg1β acts in cardiac cells are still poorly understood. In the present study, we analyzed the effects of Nrg1β on glucose uptake in neonatal rat ventricular myocytes and investigated to what extent mTOR/Akt signaling pathways are implicated. We show that Nrg1β enhances glucose uptake in cardiomyocytes as efficiently as IGF-I and insulin. Nrg1β causes phosphorylation of ErbB2 and ErbB4 and rapidly induces the phosphorylation of FAK (Tyr861), Akt (Thr308 and Ser473), and its effector AS160 (Thr642). Knockdown of ErbB2 or ErbB4 reduces Akt phosphorylation and blocks the glucose uptake. The Akt inhibitor VIII and the PI3K inhibitors LY-294002 and Byl-719 abolish Nrg1β-induced phosphorylation and glucose uptake. Finally, specific mTORC2 inactivation after knockdown of rictor blocks the Nrg1β-induced increases in Akt-p-Ser473 but does not modify AS160-p-Thr642 or the glucose uptake responses to Nrg1β. In conclusion, our study demonstrates that Nrg1β enhances glucose uptake in cardiomyocytes via ErbB2/ErbB4 heterodimers, PI3Kα, and Akt. Furthermore, although Nrg1β activates mTORC2, the resulting Akt-Ser473 phosphorylation is not essential for glucose uptake induction. These new insights into pathways whereby Nrg1β regulates glucose uptake in cardiomyocytes may contribute to the understanding of its regenerative capacity and protective function in heart failure.

Necrostatin-1 Analog DIMO Exerts Cardioprotective Effect against Ischemia Reperfusion Injury by Suppressing Necroptosis via Autophagic Pathway in Rats

Pharmacology ◽  
2021 ◽  
Vol 106 (3-4) ◽  
pp. 189-201
Author(s):  
Shigang Qiao ◽  
Wen-jie Zhao ◽  
Huan-qiu Li ◽  
Gui-zhen Ao ◽  
Jian-zhong An ◽  
...  
Keyword(s):  
Cell Death ◽  
Ischemia Reperfusion Injury ◽  
Myocardial Infarct ◽  
Ischemia Reperfusion ◽  
Glucose Deprivation ◽  
Neonatal Rat ◽  
Ligand Docking ◽  
Autophagic Flux ◽  
Myocardial Infarct Size ◽  
Rat Cardiomyocytes

Aim: It has been reported that necrostatin-1 (Nec-1) is a specific necroptosis inhibitor that could attenuate programmed cell death induced by myocardial ischemia/reperfusion (I/R) injury. This study aimed to observe the effect and mechanism of novel Nec-1 analog (Z)-5-(3,5-dimethoxybenzyl)-2-imine-1-methylimidazolin-4-1 (DIMO) on myocardial I/R injury. Methods: Male SD rats underwent I/R injury with or without different doses of DIMO (1, 2, or 4 mg/kg) treatment. Isolated neonatal rat cardiomyocytes were subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) treatment with or without DIMO (0.1, 1, 10, or 100 μM). Myocardial infarction was measured by TTC staining. Cardiomyocyte injury was assessed by lactate dehydrogenase assay (LDH) and flow cytometry. Receptor-interacting protein 1 kinase (RIP1K) and autophagic markers were detected by co-immunoprecipitation and Western blotting analysis. Molecular docking of DIMO into the ATP binding site of RIP1K was performed using GLIDE. Results: DIMO at doses of 1 or 2 mg/kg improved myocardial infarct size. However, the DIMO 4 mg/kg dose was ineffective. DIMO at the dose of 0.1 μM decreased LDH leakage and the ratio of PI-positive cells followed by OGD/R treatment. I/R or OGD/R increased RIP1K expression and in its interaction with RIP3K, as well as impaired myocardial autophagic flux evidenced by an increase in LC3-II/I ratio, upregulated P62 and Beclin-1, and activated cathepsin B and L. In contrast, DIMO treatment reduced myocardial cell death and reversed the above mentioned changes in RIP1K and autophagic flux caused by I/R and OGD/R. DIMO binds to RIP1K and inhibits RIP1K expression in a homology modeling and ligand docking. Conclusion: DIMO exerts cardioprotection against I/R- or OGD/R-induced injury, and its mechanisms may be associated with the reduction in RIP1K activation and restoration impaired autophagic flux.

Percutaneous Intracoronary Delivery of Plasma Extracellular Vesicles Protects the Myocardium Against Ischemia-Reperfusion Injury in Canis

Hypertension ◽  
2021 ◽  
Vol 78 (5) ◽  
pp. 1541-1554
Author(s):  
Hongyun Wang ◽  
Rusitanmujiang Maimaitiaili ◽  
Jianhua Yao ◽  
Yuling Xie ◽  
Sujing Qiang ◽  
...  
Keyword(s):  
Stem Cell ◽  
Embryonic Stem Cell ◽  
Human Embryonic Stem Cell ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Embryonic Stem ◽  
Cardiomyocyte Apoptosis ◽  
Neonatal Rat ◽  
Rat Cardiomyocytes ◽  
Neonatal Rat Cardiomyocytes

Plasma circulating extracellular vesicles (EVs) have been utilized as a potential therapeutic strategy to treat ischemic disease through intramyocardial injection (efficient but invasive) or tail vein injection (noninvasive but low cardiac retention). An effective and noninvasive delivery of EVs for future clinical use is necessary. The large animal (canine) model was complemented with a murine ischemia-reperfusion injury (IRI) model, as well as H9 human embryonic stem cell–induced cardiomyocytes or neonatal rat cardiomyocytes to investigate the effective delivery method and the role of plasma EVs in the IRI model. We further determine the crucial molecule within EVs that confers the cardioprotective role in vivo and in vitro and investigate the efficiency of CHP (cardiac homing peptide)-linked EVs in alleviating IRI. D-SPECT imaging showed that percutaneous intracoronary delivery of EVs reduced infarct extent in dogs. CHP-EVs further reduced IRI-induced cardiomyocyte apoptosis in mice and neonatal rat cardiomyocytes. Mechanistically, administration of EVs by percutaneous intracoronary delivery (in dog) and myocardial injection (in mice) just before reperfusion reduced infarct size of IRI by increasing miR-486 levels. miR-486–deleted EVs exacerbated oxygen-glucose deprivation/reoxygenation–induced human embryonic stem cell–induced cardiomyocytes and neonatal rat cardiomyocyte apoptosis. EV-miR-486 inhibited the PTEN (phosphatase and tensin homolog deleted on chromosome ten) expression and then promoted AKT (protein kinase B) activation in human embryonic stem cell–induced cardiomyocytes and neonatal rat cardiomyocytes. In conclusion, plasma-derived EVs convey miR-486 to the myocardium and attenuated IRI-induced infarction and cardiomyocyte apoptosis. CHP strategy was effective to improve cardiac retention of EVs in mice (in vivo) and dogs (ex vivo).

scholarly journals The Cardioprotective Effects of Hydrogen Sulfide in Heart Diseases: From Molecular Mechanisms to Therapeutic Potential

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Yaqi Shen ◽  
Zhuqing Shen ◽  
Shanshan Luo ◽  
Wei Guo ◽  
Yi Zhun Zhu
Keyword(s):  
Hydrogen Sulfide ◽  
Molecular Mechanisms ◽  
Inflammatory Responses ◽  
Ischemia Reperfusion Injury ◽  
Therapeutic Potential ◽  
Heart Diseases ◽  
Ischemia Reperfusion ◽  
Cardiac Diseases ◽  
Mammalian Tissues ◽  
Antioxidative Action

Hydrogen sulfide (H2S) is now recognized as a third gaseous mediator along with nitric oxide (NO) and carbon monoxide (CO), though it was originally considered as a malodorous and toxic gas. H2S is produced endogenously from cysteine by three enzymes in mammalian tissues. An increasing body of evidence suggests the involvement of H2S in different physiological and pathological processes. Recent studies have shown that H2S has the potential to protect the heart against myocardial infarction, arrhythmia, hypertrophy, fibrosis, ischemia-reperfusion injury, and heart failure. Some mechanisms, such as antioxidative action, preservation of mitochondrial function, reduction of apoptosis, anti-inflammatory responses, angiogenic actions, regulation of ion channel, and interaction with NO, could be responsible for the cardioprotective effect of H2S. Although several mechanisms have been identified, there is a need for further research to identify the specific molecular mechanism of cardioprotection in different cardiac diseases. Therefore, insight into the molecular mechanisms underlying H2S action in the heart may promote the understanding of pathophysiology of cardiac diseases and lead to new therapeutic targets based on modulation of H2S production.

scholarly journals Gossypol Acetic Acid Attenuates Cardiac Ischemia/Reperfusion Injury in Rats via an Antiferroptotic Mechanism

Biomolecules ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1667
Author(s):  
Jian-Hong Lin ◽  
Kun-Ta Yang ◽  
Pei-Ching Ting ◽  
Yu-Po Luo ◽  
Ding-Jyun Lin ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Cell Death ◽  
Acetic Acid ◽  
Ischemia Reperfusion ◽  
Neonatal Rat ◽  
Mrna Levels ◽  
H9c2 Cells ◽  
Rat Cardiomyocytes ◽  
Protein Levels ◽  
Gossypol Acetic Acid

Myocardial ischemia/reperfusion (I/R) injury has been associated with ferroptosis, which is characterized by an iron-dependent accumulation of lipid peroxide to lethal levels. Gossypol acetic acid (GAA), a natural product taken from the seeds of cotton plants, prevents oxidative stress. However, the effects of GAA on myocardial I/R-induced ferroptosis remain unclear. This study investigated the ability of GAA to attenuate I/R-induced ferroptosis in cardiomyocytes along with the underlying mechanisms in a well-established rat model of myocardial I/R and isolated neonatal rat cardiomyocytes. H9c2 cells and cardiomyocytes were treated with the ferroptosis inducers erastin, RSL3, and Fe-SP. GAA could protect H9c2 cells against ferroptotic cell death caused by these ferroptosis inducers by decreasing the production of malondialdehyde and reactive oxygen species, chelating iron content, and downregulating mRNA levels of Ptgs2. GAA could prevent oxygen-glucose deprivation/reperfusion-induced cell death and lipid peroxidation in the cardiomyocytes. Moreover, GAA significantly attenuated myocardial infarct size, reduced lipid peroxidation, decreased the mRNA levels of the ferroptosis markers Ptgs2 and Acsl4, decreased the protein levels of ACSL4 and NRF2, and increased the protein levels of GPX4 in I/R-induced ex vivo rat hearts. Thus, GAA may play a cytoprotectant role in ferroptosis-induced cardiomyocyte death and myocardial I/R-induced ferroptotic cell death.

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