scholarly journals Ischemic postconditioning and pinacidil suppress calcium overload in anoxia-reoxygenation cardiomyocytes via down-regulation of the calcium-sensing receptor

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2612 ◽  
Author(s):  
Lin Zhang ◽  
Song Cao ◽  
Shengli Deng ◽  
Gang Yao ◽  
Tian Yu
Keyword(s):  
Ischemia Reperfusion ◽  
Calcium Overload ◽  
Ischemic Postconditioning ◽  
Free Calcium ◽  
Protective Mechanism ◽  
Calcium Sensing Receptor ◽  
Down Regulation ◽  
Rat Cardiomyocytes ◽  
Adult Rat ◽  
Calcium Sensing

Ischemic postconditioning (IPC) and ATP sensitive potassium channel (KATP) agonists (e.g. pinacidil and diazoxide) postconditioning are effective methods to defeat myocardial ischemia-reperfusion (I/R) injury, but their specific mechanisms of reducing I/R injury are not fully understood. We observed an intracellular free calcium ([Ca2+]i) overload in Anoxia/reoxygenation (A/R) cardiomyocytes, which can be reversed by KATP agonists diazoxide or pinacidil. The calcium-sensing receptor (CaSR) regulates intracellular calcium homeostasis. CaSR was reported to be involved in the I/R-induced apoptosis in rat cardiomyocytes. We therefore hypothesize that IPC and pinacidil postconditioning (PPC) reduce calcium overload in I/R cardiomyocytes by the down-regulation of CaSR. A/R model was established with adult rat caridomyocyte. mRNA and protein expression of CaSR were detected, IPC, PPC and KATP’s effects on [Ca2+]i concentration was assayed too. IPC and PPC ameliorated A/R insult induced [Ca2+]i overload in cardiomyocytes. In addition, they down-regulated the mRNA and protein level of CaSR as we expected. CaSR agonist spermine and KATP blocker glibenclamide offset IPC’s effects on CaSR expression and [Ca2+]i modulation. Our data indicate that CaSR down-regulation contributes to the mitigation of calcium overload in A/R cardiomyocytes, which may partially represents IPC and KATP’s myocardial protective mechanism under I/R circumstances.

scholarly journals Cardiac-targeted PIASy Gene Silencing Mediates deSUMOylation of Caveolin-3 and Prevents Ischemia/reperfusion-induced Nav1.5 Down-regulation and Ventricular Arrhythmias

2021 ◽  
Author(s):  
Chenchen Hu ◽  
Xin Wei ◽  
Jinmin Liu ◽  
Linlin Han ◽  
Chengkun Xia ◽  
...  
Keyword(s):  
Gene Silencing ◽  
Ventricular Arrhythmias ◽  
Heart Diseases ◽  
Ischemia Reperfusion ◽  
Intraventricular Injection ◽  
Membrane Expression ◽  
Down Regulation ◽  
Rat Cardiomyocytes ◽  
Adult Rat

Abstract Background: Abnormal myocardial expression and function of Nav1.5 causes lethal ventricular arrhythmias during myocardial ischemia-reperfusion (I/R). PIASy mediated Caveolin-3 (Cav-3) SUMO modification affects Cav-3 binding to ligand Nav1.5. PIASy activity is increased after myocardial I/R, whether or not this may be attributable to plasma membrane Nav1.5 downregulation and ventricular arrhythmias remains unclear. Methods: Using recombinant adeno-associated virus subtype 9 (AAV9), rat cardiac PIASy was silenced by intraventricular injection of PIASy shRNA. Two weeks later, the hearts were subjected to I/R, and electrocardiography was performed to assess malignant arrhythmias. Tissues from peri-infarct areas of the left ventricle were collected for molecular biological measurement. Results: We found that PIASy was upregulated by I/R, with increased SUMO2/3 modification of Cav-3, reduced membrane Nav1.5 density, and increased ventricular arrhythmia frequency. These effects were significantly reversed by PIASy silencing. In addition, PIASy silencing enhanced Cav-3 binding to Nav1.5 and prevented I/R-induced Nav1.5 re-localization. Using in vitro models of HEK293T cells and isolated adult rat cardiomyocytes exposed to hypoxia/reoxygenation (H/R), this reserch further confirmed that PIASy promoted Cav-3 modification by SUMO2/3 and Nav1.5/Cav-3 dissociation after H/R. Mutation of the SUMO Consensus Sites Lysine in Cav-3 (K38R or K144R) alters the membrane expression levels of Nav1.5 and Cav-3 before and after H/R in HEK293T cells. Conclusions: I/R-induced cardiac PIASy activation contributes to Cav-3 SUMOylation by SUMO2/3 and dysregulated Nav1.5- related ventricular arrhythmias. Cardiac-targeted PIASy gene silencing mediates deSUMOylation of Cav-3 and prevents I/R-induced Nav1.5 down-regulation and ventricular arrhythmias in rats, identifying PIASy as a potential therapeutic target for relevant life-threatening arrhythmias in patients with ischemic heart diseases.

Involvement of calcium-sensing receptor in ischemia/reperfusion-induced apoptosis in rat cardiomyocytes

2006 ◽  
Vol 347 (4) ◽  
pp. 872-881 ◽  
Author(s):  
Wei-hua Zhang ◽  
Song-bin Fu ◽  
Fang-hao Lu ◽  
Bo Wu ◽  
Dong-mei Gong ◽  
...  
Keyword(s):  
Ischemia Reperfusion ◽  
Calcium Sensing Receptor ◽  
Rat Cardiomyocytes ◽  
Calcium Sensing ◽  
Induced Apoptosis

Distinct Roles for Sarcolemmal and Mitochondrial Adenosine Triphosphate-sensitive Potassium Channels in Isoflurane-induced Protection against Oxidative Stress

2006 ◽  
Vol 105 (1) ◽  
pp. 98-104 ◽  
Author(s):  
Jasna Marinovic ◽  
Zeljko J. Bosnjak ◽  
Anna Stadnicka
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Adenosine Triphosphate ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Protective Mechanism ◽  
Trypan Blue Exclusion ◽  
Rat Cardiomyocytes ◽  
Adult Rat ◽  
Cardiac Preconditioning

Background Cardiac preconditioning, including that induced by halogenated anesthetics, is an innate protective mechanism against ischemia-reperfusion injury. The adenosine triphosphate-sensitive potassium (K(ATP)) channels are considered essential in preconditioning mechanism. However, it is unclear whether K(ATP) channels are triggers initiating the preconditioning signaling, and/or effectors responsible for the cardioprotective memory and activated during ischemia-reperfusion. Methods Adult rat cardiomyocytes were exposed to oxidative stress with 200 microM H(2)O(2) and 100 microM FeSO4. Myocyte survival was determined based on morphologic characteristics and trypan blue exclusion. To induce preconditioning, the myocytes were pretreated with isoflurane. The involvement of sarcolemmal and mitochondrial K(ATP) channels was investigated using specific inhibitors HMR-1098 and 5-hydroxydecanoic acid. Data are expressed as mean +/- SD. Results Oxidative stress induced cell death in 47 +/- 14% of myocytes. Pretreatment with isoflurane attenuated this effect to 26 +/- 8%. Blockade of the sarcolemmal K(ATP) channels abolished the protection by isoflurane pretreatment when HMR-1098 was applied throughout the experiment (50 +/- 21%) or only during oxidative stress (50 +/- 12%), but not when applied during isoflurane pretreatment (29 +/- 13%). Inhibition of the mitochondrial K(ATP) channels abolished cardioprotection irrespective of the timing of 5-hydroxydecanoic acid application. Cell death was 42 +/- 23, 45 +/- 23, and 46 +/- 22% when 5-hydroxydecanoic acid was applied throughout the experiment, only during isoflurane pretreatment, or only during oxidative stress, respectively. Conclusion The authors conclude that both sarcolemmal and mitochondrial K(ATP) channels play essential and distinct roles in protection afforded by isoflurane. Sarcolemmal K(ATP) channel seems to act as an effector of preconditioning, whereas mitochondrial K(ATP) channel plays a dual role as a trigger and an effector.

scholarly journals IP3R1 regulates Ca2+ transport and pyroptosis through the NLRP3/Caspase-1 pathway in myocardial ischemia/reperfusion injury

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Guixi Mo ◽  
Xin Liu ◽  
Yiyue Zhong ◽  
Jian Mo ◽  
Zhiyi Li ◽  
...  
Keyword(s):  
Myocardial Ischemia ◽  
Ischemia Reperfusion Injury ◽  
Cell Model ◽  
Ischemia Reperfusion ◽  
Inflammatory Factors ◽  
Rat Cardiomyocytes ◽  
Adult Rat ◽  
Caspase 1 ◽  
Intracellular Ca ◽  
Myocardial Ischemia Reperfusion

AbstractIntracellular ion channel inositol 1,4,5-triphosphate receptor (IP3R1) releases Ca2+ from endoplasmic reticulum. The disturbance of IP3R1 is related to several neurodegenerative diseases. This study investigated the mechanism of IP3R1 in myocardial ischemia/reperfusion (MI/R). After MI/R modeling, IP3R1 expression was silenced in myocardium of MI/R rats to explore its role in the concentration of myocardial enzymes, infarct area, Ca2+ level, NLRP3/Caspase-1, and pyroptosis markers and inflammatory factors. The adult rat cardiomyocytes were isolated and cultured to establish hypoxia/reperfusion (H/R) cell model. The expression of IP3R1 was downregulated or ERP44 was overexpressed in H/R-induced cells. Nifedipine D6 was added to H/R-induced cells to block Ca2+ channel or Nigericin was added to activate NLRP3. IP3R1 was highly expressed in myocardium of MI/R rats, and silencing IP3R1 alleviated MI/R injury, reduced Ca2+ overload, inflammation and pyroptosis in MI/R rats, and H/R-induced cells. The binding of ERP44 to IP3R1 inhibited Ca2+ overload, alleviated cardiomyocyte inflammation, and pyroptosis. The increase of intracellular Ca2+ level caused H/R-induced cardiomyocyte pyroptosis through the NLRP3/Caspase-1 pathway. Activation of NLRP3 pathway reversed the protection of IP3R1 inhibition/ERP44 overexpression/Nifedipine D6 on H/R-induced cells. Overall, ERP44 binding to IP3R1 inhibits Ca2+ overload, thus alleviating pyroptosis and MI/R injury.

scholarly journals A Novel Role for the Calcium Sensing Receptor in Rat Diabetic Encephalopathy

2015 ◽  
Vol 35 (1) ◽  
pp. 38-50 ◽  
Author(s):  
Shiyun Dong ◽  
Gang Li ◽  
Dan Zheng ◽  
Jichao Wu ◽  
Dianjun Sun ◽  
...  
Keyword(s):  
Hippocampal Neurons ◽  
Laser Scanning ◽  
Laser Scanning Confocal Microscopy ◽  
Diabetic Rats ◽  
Neonatal Rat ◽  
Protective Mechanism ◽  
Diabetic Encephalopathy ◽  
Calcium Sensing Receptor ◽  
Scanning Confocal Microscopy ◽  
Calcium Sensing

Background: Diabetic encephalopathy is a common complication of diabetes, and it may be involved in altering intracellular calcium concentrations ([Ca2+]i) at its onset. The calcium sensing receptor (CaSR) is a G-protein coupled receptor, however, the functional involvement of CaSR in diabetic encephalopathy remains unclear. Methods: In this study, diabetic rats were modeled by STZ (50 mg/kg). At the end of 4, 8 and 12 weeks, the CaSR expression in hippocampus was analyzed by Western blot. In neonatal rat hippocampal neurons, the [Ca2+]i was detected by laser scanning confocal microscopy, the production of reactive oxygen species (ROS) in mitochondria, the level of NO and the mitochondrial transmembrane potential were measured by MitoSOX, DAF-FM and JC-1, respectively. Results: Our results showed in hippocampal neurons treated with high glucose, CaSR regulated [Ca2+]i through the PLC-IP3 pathway. CaSR expression was decreased and was involved in the changes in [Ca2+]i. Mitochondrial membrane potential, NO release and expression of p-eNOS decreased, while the production of ROS in mitochondria increased. Conclusion: Down-regulation of CaSR expression was accompanied by neuronal injury, calcium disturbance, increased ROS production and decreased release of NO. Up-regulation of CaSR expression attenuated these changes through a positive compensatory protective mechanism to inhibit and delay diabetic encephalopathy in rats.

scholarly journals Autophagy and protein kinase C are required for cardioprotection by sulfaphenazole

2010 ◽  
Vol 298 (2) ◽  
pp. H570-H579 ◽  
Author(s):  
Chengqun Huang ◽  
Wayne Liu ◽  
Cynthia N. Perry ◽  
Smadar Yitzhaki ◽  
Youngil Lee ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Enhanced Recovery ◽  
Ischemia Reperfusion ◽  
Dominant Negative ◽  
Rat Cardiomyocytes ◽  
Adult Rat ◽  
Kinase C ◽  
Rat Hearts

Previously, we showed that sulfaphenazole (SUL), an antimicrobial agent that is a potent inhibitor of cytochrome P4502C9, is protective against ischemia-reperfusion (I/R) injury (Ref. 15 ). The mechanism, however, underlying this cardioprotection, is largely unknown. With evidence that activation of autophagy is protective against simulated I/R in HL-1 cells, and evidence that autophagy is upregulated in preconditioned hearts, we hypothesized that SUL-mediated cardioprotection might resemble ischemic preconditioning with respect to activation of protein kinase C and autophagy. We used the Langendorff model of global ischemia to assess the role of autophagy and protein kinase C in myocardial protection by SUL during I/R. We show that SUL enhanced recovery of function, reduced creatine kinase release, decreased infarct size, and induced autophagy. SUL also triggered PKC translocation, whereas inhibition of PKC with chelerythrine blocked the activation of autophagy in adult rat cardiomyocytes. In the Langendorff model, chelerythrine suppressed autophagy and abolished the protection mediated by SUL. SUL increased autophagy in adult rat cardiomyocytes infected with GFP-LC3 adenovirus, in isolated perfused rat hearts, and in mCherry-LC3 transgenic mice. To establish the role of autophagy in cardioprotection, we used the cell-permeable dominant-negative inhibitor of autophagy, Tat-Atg5K130R. Autophagy and cardioprotection were abolished in rat hearts perfused with recombinant Tat-Atg5K130R. Taken together, these studies indicate that cardioprotection mediated by SUL involves a PKC-dependent induction of autophagy. The findings suggest that autophagy may be a fundamental process that enhances the heart's tolerance to ischemia.

Luteolin improves contractile function and attenuates apoptosis following ischemia–reperfusion in adult rat cardiomyocytes

2011 ◽  
Vol 668 (1-2) ◽  
pp. 201-207 ◽  
Author(s):  
Lingling Qi ◽  
Huanjun Pan ◽  
Dongye Li ◽  
Fang Fang ◽  
Dan Chen ◽  
...  
Keyword(s):  
Contractile Function ◽  
Ischemia Reperfusion ◽  
Rat Cardiomyocytes ◽  
Adult Rat

Calcitriol Prevents In Vitro Vascular Smooth Muscle Cell Mineralization by Regulating Calcium-Sensing Receptor Expression

Endocrinology ◽  
2015 ◽  
Vol 156 (6) ◽  
pp. 1965-1974 ◽  
Author(s):  
Aurélien Mary ◽  
Lucie Hénaut ◽  
Cédric Boudot ◽  
Isabelle Six ◽  
Michel Brazier ◽  
...  
Keyword(s):  
Vitamin D ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Small Interfering Rna ◽  
Receptor Expression ◽  
Calcium Sensing Receptor ◽  
Down Regulation ◽  
Calcium Sensing ◽  
Cardiovascular Morbidity And Mortality ◽  
Interfering Rna

Abstract Vascular calcification (VC) is a degenerative disease that contributes to cardiovascular morbidity and mortality. A negative relationship has been demonstrated between VC and calcium sensing receptor (CaSR) expression in the vasculature. Of interest, vitamin D response elements, which allow responsiveness to 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], are present in the promoters of the CaSR gene. We hypothesized that 1,25(OH)2D3, by modulating CaSR expression in vascular smooth muscle cells (VSMCs), might protect against VC. Human VSMCs were exposed to increasing concentrations of 1,25(OH)2D3 (0.01–10 nmol/L) in noncalcifying (1.8 mmol/L) or procalcifying Ca2+0 condition (5.0 mmol/L). Using quantitative RT-PCR and Western blotting we observed a significant increase in both CaSR mRNA and protein levels after exposure to 1.0 nmol/L 1,25(OH)2D3. This effect was associated with a maximal increase in CaSR expression at the cell surface after 48 hours of 1,25(OH)2D3 treatment, as assessed by flow cytometry. Down-regulation of the vitamin D receptor by small interfering RNA abolished these effects. In the procalcifying condition, 1.0 nmol/L 1,25(OH)2D3 blocked the Ca2+0-induced decrease in total and surface CaSR expression and protected against mineralization. Down-regulation of CaSR expression by CaSR small interfering RNA abolished this protective effect. 1,25(OH)2D3 concentrations of 0.5 and 5.0 nmol/L were also effective, but other (0.01, 0.1, and 10 nmol/L) concentrations did not modify CaSR expression and human VSMC mineralization. In conclusion, these findings suggest that nanomolar concentrations of 1,25(OH)2D3 induce a CaSR-dependent protection against VC. Both lower and higher concentrations are either ineffective or may even promote VC. Whether this also holds true in the clinical setting requires further study.

scholarly journals Protective Effect and Mechanism of Total Flavones fromRhododendron simsiiPlanch Flower on Cultured Rat Cardiomyocytes with Anoxia and Reoxygenation

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Yi Jiao ◽  
Yi-Fei Fan ◽  
Yu-Ling Wang ◽  
Jun-Yan Zhang ◽  
Shuo Chen ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Protective Effect ◽  
Cell Viability ◽  
Ischemia Reperfusion ◽  
Cellular Damage ◽  
Protective Mechanism ◽  
Patch Clamp Technique ◽  
Rat Cardiomyocytes ◽  
Whole Cell Patch Clamp ◽  
Myocardial Ischemia Reperfusion

Many flavonoids have cardioprotection against myocardial ischemia/reperfusion (I/R) injury. Total flavones fromRhododendron simsiiPlanch flower (TFR) can protect myocardial ischemic injuries. However, its protective mechanism is still unknown. The present study was designed to investigate the mechanism of TFR on myocardial I/R and anoxia/reoxygenation (A/R) injuries. Rat model of myocardial I/R injury was made, and myocardial infarction was determined. A/R injury was induced in cultured rat cardiomyocytes; cellular damage was evaluated by measuring cell viability, LDH and cTnT releases, and MDA content. Expressions of ROCK1and ROCK2protein were examined by Western blot analysis, and K+currents were recorded by using whole-cell patch clamp technique. TFR 20~80 mg/kg markedly reduced I/R-induced myocardial infarction. TFR 3.7~300 mg/L significantly inhibited A/R-induced reduction of cell viability, LDH and cTnT releases, and MDA production. Exposure to A/R significantly increased ROCK1and ROCK2expressions in rat cardiomyocytes, but TFR 33.3~300 mg/L obviously inhibited this increase. 300 mg/L TFR significantly augmented inward rectifier K+current and other K+currents in rat cardiomyocytes. These results indicate that TFR has a protective effect on rat cardiomyocytes A/R damage, and the protective mechanism may be engaged with the inhibition of ROCK1and ROCK2and activation of K+channels.

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