Antagonism of endothelin-1 inhibits hypoxia-induced apoptosis in cardiomyocytesThis article is one of a selection of papers published in the special issue (part 2 of 2) on Forefronts in Endothelin.

2008 ◽  
Vol 86 (8) ◽  
pp. 536-540 ◽  
Author(s):  
Anjing Ren ◽  
Xiaohong Yan ◽  
Hong Lu ◽  
Jingsong Shi ◽  
Yuanjun Yin ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Annexin V ◽  
Neonatal Rat ◽  
Receptor Subtypes ◽  
Rat Cardiomyocytes ◽  
Endothelin 1 ◽  
Apoptosis Rate ◽  
Hypoxic Conditions ◽  
Induced Apoptosis

Apoptosis is well documented to be a common feature of many pathological processes of the heart. Exogenous endothelin-1 (ET-1) has been shown to be proapoptotic or antiapoptotic, depending on ET-1 concentration, cell type, and the ratio of ETA/ETB receptor subtypes. The role of endogenous ET-1 in cardiomyocyte apoptosis, however, is not clarified. This study observed the effects of the ETA-receptor antagonists BQ610 and BQ123 and the ETB-receptor antagonist BQ788 on hypoxia-induced apoptosis in primary cultured neonatal rat cardiomyocytes. Hypoxic apoptosis was induced by incubating cardiomyocytes in serum-free medium under 3% O2 and 5% CO2 for 24 h and evaluated by TUNEL analysis and flow cytometry. TUNEL analysis showed that the apoptotic cardiomyocytes constituted 24.2% ± 2.2% of the total cells under hypoxic conditions. Treatment with BQ610 (5 μmol/L) significantly reduced the apoptosis rate to 13.2% ± 3.7% (data from 4 independent experiments, p < 0.01 vs. hypoxia). Flow cytometry showed that the percentage of apoptotic cells positively stained with annexin V and propidium iodide was 42.76% ± 4.44% (n = 12) in cultures subjected to hypoxia. BQ123 at 0.04, 0.2, and 1.0 μmol/L dose-dependently reduced the apoptosis rate to 34.00% ± 10.35% (n = 6, p < 0.05), 30.38% ± 8.28% (n = 6, p < 0.01), and 22.89% ± 4.19% (n = 6, p < 0.01), respectively. In contrast, BQ788 did not affect hypoxic apoptosis. These findings suggested that endogenous ET-1 contributed to hypoxia-induced apoptosis in cultured cardiomyocytes, which was mediated by ETA receptors, but not by ETB receptors.

Diazoxide triggers cardioprotection against apoptosis induced by oxidative stress

2003 ◽  
Vol 284 (6) ◽  
pp. H2235-H2241 ◽  
Author(s):  
Masashi Ichinose ◽  
Hidetoshi Yonemochi ◽  
Toshiaki Sato ◽  
Tetsunori Saikawa
Keyword(s):  
Oxidative Stress ◽  
Flow Cytometry ◽  
Time Course ◽  
Channel Blocker ◽  
Annexin V ◽  
Neonatal Rat ◽  
Nuclear Staining ◽  
Protective Effects ◽  
Rat Cardiomyocytes ◽  
Induced Apoptosis

Although mitochondrial ATP-sensitive potassium (mitoKATP) channels have been reported to reduce the extent of apoptosis, the critical timing of mitoKATP channel opening required to protect myocytes against apoptosis remains unclear. In the present study, we examined whether the mitoKATP channel serves as a trigger of cardioprotection against apoptosis induced by oxidative stress. Apoptosis of cultured neonatal rat cardiomyocytes was determined by flow cytometry (light scatter and propidium iodide/annexin V-FITC fluorescence) and by nuclear staining with Hoechst 33342. Mitochondrial membrane potential (ΔΨ) was measured by flow cytometry of cells stained with rhodamine-123 (Rh-123). Exposure to H2O2 (500 μM) induced apoptosis, and the percentage of apoptotic cells increased progressively and peaked at 2 h. This H2O2-induced apoptosis was associated with the loss of ΔΨ, and the time course of decrease in Rh-123 fluorescence paralleled that of apoptosis. Pretreatment of cardiomyocytes with diazoxide (100 μM), a putative mitoKATP channel opener, for 30 min before exposure to H2O2 elicited transient and mild depolarization of ΔΨ and consequently suppressed both apoptosis and ΔΨ loss after 2-h exposure to H2O2. These protective effects of diazoxide were abrogated by the mitoKATP channel blocker 5-hydroxydecanoate (500 μM) but not by the sarcolemmal KATP channel blocker HMR-1098 (30 μM). Our results suggest for the first time that diazoxide-induced opening of mitoKATP channels triggers cardioprotection against apoptosis induced by oxidative stress in rat cardiomyocytes.

scholarly journals Trophic effect of angiotensin II in neonatal rat cardiomyocytes: role of endothelin-1 and non-myocyte cells

1997 ◽  
Vol 121 (1) ◽  
pp. 118-124 ◽  
Author(s):  
Klaus Pönicke ◽  
Ingrid Heinroth-Hoffmann ◽  
Karin Becker ◽  
Otto-Erich Brodde
Keyword(s):  
Angiotensin Ii ◽  
Neonatal Rat ◽  
Rat Cardiomyocytes ◽  
Trophic Effect ◽  
Endothelin 1 ◽  
Neonatal Rat Cardiomyocytes

scholarly journals FNDC5/Irisin counteracts lipotoxic-induced apoptosis in hypoxic H9c2 cells

2019 ◽  
Vol 63 (2) ◽  
pp. 151-159 ◽  
Author(s):  
Isabel Moscoso ◽  
María Cebro-Márquez ◽  
Moisés Rodríguez-Mañero ◽  
José Ramón González-Juanatey ◽  
Ricardo Lage
Keyword(s):  
Myocardial Infarction ◽  
Annexin V ◽  
Protective Role ◽  
H9c2 Cells ◽  
Hypoxic Conditions ◽  
Potential Therapeutic Role ◽  
Induced Apoptosis ◽  
And Oxidative Stress ◽  
Apoptotic Cascade

Irisin is a newly identified adipokine critical to modulate body metabolism, fatty acid metabolism and oxidative stress; recent evidence suggests a cardioprotective role in ischemic injury. Loss of cardiomyocytes during acute myocardial infarction is strongly associated with energetic changes and lipotoxic-induced apoptosis. Our aim was to study FNDC5/irisin’s potential protective role against hypoxia and lipotoxicity, both related with myocardial infarction environment. H9c2 cells were treated with palmitate and/or irisin in normoxic/hypoxic conditions. Cell viability and apoptosis were assessed by MTT assay and annexin V/PI staining. Immunoblotting was used to confirm apoptotic cascade regulation. Irisin counteracts lipotoxic-induced apoptosis in hypoxic cardiomyoblasts by activating Akt signaling pathway suggesting the potential therapeutic role of irisin in ischemic heart disease.

Role of cAMP and calcium influx in endothelin-1-induced ANP release in rat cardiomyocytes

1997 ◽  
Vol 273 (5) ◽  
pp. E922-E931 ◽  
Author(s):  
M. C. Rebsamen ◽  
D. J. Church ◽  
D. Morabito ◽  
M. B. Vallotton ◽  
U. Lang
Keyword(s):  
Calcium Influx ◽  
Cytosolic Calcium ◽  
Neonatal Rat ◽  
Rat Cardiomyocytes ◽  
Endothelin 1 ◽  
Kinase C ◽  
Ventricular Cardiomyocytes ◽  
Camp Formation ◽  
Prostacyclin Production

The mechanism of endothelin-1 (ET-1)-induced atrial natriuretic peptide (ANP) release was studied in neonatal rat ventricular cardiomyocytes. These cells expressed a single high-affinity class of ETAreceptor (dissociation constant = 54 ± 18 pM, n = 3), but no ETB receptors. Incubation of cardiomyocytes with ET-1 led to concentration-dependent ANP release and prostacyclin production. ET-1-induced ANP release was affected by neither protein kinase C (PKC) inhibition or downregulation nor by cyclooxygenase inhibition, indicating that ET-1-stimulated ANP secretion is not a PKC-mediated, prostaglandin-dependent process. Furthermore, ET-1 significantly stimulated adenosine 3′,5′-cyclic monophosphate (cAMP) production and increased cytosolic calcium concentration in these preparations. Both ET-1-induced calcium influx and ANP release were decreased by the cAMP antagonist Rp-cAMPS, the Rp diastereoisomer of cAMP. Moreover, ET-1-induced ANP secretion was strongly inhibited in the presence of nifedipine as well as in the absence of extracellular calcium. Thus our results suggest that ET-1 stimulates ANP release in ventricular cardiomyocytes via an ETAreceptor-mediated pathway involving cAMP formation and activation of a nifedipine-sensitive calcium channel.

Abstract 862: Ser517:-phosphorylation Of Sirt1 Is Required For Its Pi3k/akt-mediated Nuclear Translocation And Cardiomyocyte Protection Against Oxidant Stress In Failing Hearts.

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Masaya Tanno ◽  
Tetsuji Miura ◽  
Takayuki Miki ◽  
Toshiyuki Yano ◽  
Yoshiyuki Horio ◽  
...  
Keyword(s):  
Nuclear Translocation ◽  
Oxidant Stress ◽  
C2c12 Cells ◽  
Neonatal Rat ◽  
Rat Cardiomyocytes ◽  
Intracellular Location ◽  
Transfected Cells ◽  
Induced Apoptosis

[Purpose] We recently found that SIRT1, a protein deacetylase, shuttles between the nucleus and cytoplasm. In this study, we examined the role of nuclear SIRT1 in cardiomyocyte protection against oxidant stress and involvement of PI3K/Akt in the nuclear translocation. [Methods and Results] First, the critical intracellular location of SIRT1 for its anti-apoptotic function was examined. C2C12 cells were transfected with wild-type SIRT1 (WT) or SIRT1 with site-directed mutations in the nuclear localizing signal (mtNLS) and exposed to antimycin A (AA), an oxidative stressor. AA-induced apoptosis was suppressed in WT-transfected cells expressing SIRT1 in the nuclei compared with that in mtNLS-transfected cells expressing SIRT1 in the cytoplasm (TUNEL-positive cells = 4.4±0.7% vs. 34.6±8.0%). AA-induced apoptosis and also angiotensin II-(angII)-induced apoptosis in neonatal rat cardiomyocytes (NRCM) were suppressed by resveratrol, a SIRT1 activator. This protective effect of resveratrol was attenuated by transfection of SIRT1-siRNA but not by transfection of control siRNA. Next, we assessed the role of PI3K/Akt in nuclear translocation of SIRT1. SIRT1 in NRCM was localized in both the nucleus and cytoplasm under baseline conditions, and IGF-1 induced its nuclear translocation. This effect of IGF-1 was suppressed by LY294002 (LY), a PI3K inhibitor. Deletion mutagenesis study showed that LY-induced nuclear exclusion was observed for SIRT1[223–540] but not for SIRT1[223– 489]. Replacement of serine517 with alanine (S517A) increased cytoplasmic SIRT1, and S517A showed attenuated nuclear translocation in response to IGF-1, indicating that serine517 is the target site of PI3K/Akt. Finally, to confirm heart failure-associated SIRT1 translocation in vivo, myocardial infarction was induced in WKY rats. The number of ventricular cardiomyocytes with nuclear SIRT1 at 4 weeks after infarction was significantly larger than that in sham-operated hearts (10.2±2.9% vs. 0.7±0.2%). [Conclusion] The results suggest that phosphorylation of SIRT1 at Ser517 by PI3K/Akt is involved in nuclear translocation of SIRT1, which contributes to cardiomyocyte protection from oxidant stress-mediated injury in failing hearts.

scholarly journals Protective Effects of Shenfuyixin Granule on H2O2-Induced Apoptosis in Neonatal Rat Cardiomyocytes

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Xinlu Wang ◽  
Xuanxuan Hao ◽  
Youping Wang ◽  
Bin Li ◽  
Lin Cui ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Caspase 3 ◽  
Neonatal Rat ◽  
Caspase 8 ◽  
Caspase 9 ◽  
Rat Cardiomyocytes ◽  
Expression Levels ◽  
Apoptosis Rate ◽  
Neonatal Rat Cardiomyocytes ◽  
Mitochondrion Membrane Potential

Shenfuyixin granule (SFYXG, i.e., Xinshuaikang granule) is a prescription, commonly used in the clinical experience, which plays a significant role in the treatment of heart failure. The purpose of this present research was to investigate the protective effect of SFYXG, and the mechanism about anti-H2O2-induced oxidative stress and apoptosis in the neonatal rat cardiomyocytes. Myocardial cells, as is well known, were divided into 4 groups: normal, model, SFYXG, and coenzyme Q10 group, respectively. Cells viability was determined by MTT assay. Flow cytometry and AO/EB staining were implemented to test the apoptosis rate and intracellular reactive oxygen species (ROS) level. Mitochondrion membrane potential (MMP) was evaluated by JC-1 fluorescence probe method. The myocardial ultrastructure of mitochondrion was measured by electron microscope. The related mRNA expression levels of Bax, Bcl-2, Caspase-3, caspase-8, and caspase-9 were detected by real-time polymerase chain reaction (PCR). Also, the expression levels of Bax and Bcl-2 protein were detected by Western blot, and the expression levels of caspase-3, caspase-8, and caspase-9 protein were tested by caspase-Glo®3 Assay, caspase-Glo®8 Assay, and caspase-Glo®9 Assay, respectively. GAPDH was used as the internal reference gene/protein. The results revealed that SFYXG (0.5 mg/ml) raised the viability of myocardial cell, weakened the apoptosis rate and ROS level, corrected the mitochondrion membrane potential stability, and improved cell morphology and ultrastructure of myocardial mitochondrion. Furthermore, SFYXG upregulated the antiapoptosis gene of Bcl-2, but downregulated the proapoptosis genes of Bax, caspase-3, and caspase-9. In conclusion, SFYXG could appear to attenuate myocardial injury by its antioxidative and antiapoptosis effect.

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