scholarly journals iPLA2β Contributes to ER Stress-Induced Apoptosis during Myocardial Ischemia/Reperfusion Injury

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1446
Author(s):  
Tingting Jin ◽  
Jun Lin ◽  
Yingchao Gong ◽  
Xukun Bi ◽  
Shasha Hu ◽  
...  

Both calcium-independent phospholipase A2 beta (iPLA2β) and endoplasmic reticulum (ER) stress regulate important pathophysiological processes including inflammation, calcium homeostasis and apoptosis. However, their roles in ischemic heart disease are poorly understood. Here, we show that the expression of iPLA2β is increased during myocardial ischemia/reperfusion (I/R) injury, concomitant with the induction of ER stress and the upregulation of cell death. We further show that the levels of iPLA2β in serum collected from acute myocardial infarction (AMI) patients and in samples collected from both in vivo and in vitro I/R injury models are significantly elevated. Further, iPLA2β knockout mice and siRNA mediated iPLA2β knockdown are employed to evaluate the ER stress and cell apoptosis during I/R injury. Additionally, cell surface protein biotinylation and immunofluorescence assays are used to trace and locate iPLA2β. Our data demonstrate the increase of iPLA2β augments ER stress and enhances cardiomyocyte apoptosis during I/R injury in vitro and in vivo. Inhibition of iPLA2β ameliorates ER stress and decreases cell death. Mechanistically, iPLA2β promotes ER stress and apoptosis by translocating to ER upon myocardial I/R injury. Together, our study suggests iPLA2β contributes to ER stress-induced apoptosis during myocardial I/R injury, which may serve as a potential therapeutic target against ischemic heart disease.

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Li-Ming Yu ◽  
Xue Dong ◽  
Jian Zhang ◽  
Zhi Li ◽  
Xiao-Dong Xue ◽  
...  

Endoplasmic reticulum (ER) stress and oxidative stress contribute greatly to myocardial ischemia-reperfusion (MI/R) injury. Naringenin, a flavonoid derived from the citrus genus, exerts cardioprotective effects. However, the effects of naringenin on ER stress as well as oxidative stress under MI/R condition and the detailed mechanisms remain poorly defined. This study investigated the protective effect of naringenin on MI/R-injured heart with a focus on cyclic guanosine monophosphate- (cGMP-) dependent protein kinase (PKG) signaling. Sprague-Dawley rats were treated with naringenin (50 mg/kg/d) and subjected to MI/R surgery with or without KT5823 (2 mg/kg, a selective inhibitor of PKG) cotreatment. Cellular experiment was conducted on H9c2 cardiomyoblasts subjected to simulated ischemia-reperfusion treatment. Before the treatment, the cells were incubated with naringenin (80 μmol/L). PKGIα siRNA was employed to inhibit PKG signaling. Our in vivo and in vitro data showed that naringenin effectively improved heart function while it attenuated myocardial apoptosis and infarction. Furthermore, pretreatment with naringenin suppressed MI/R-induced oxidative stress as well as ER stress as evidenced by decreased superoxide generation, myocardial MDA level, gp91phox expression, and phosphorylation of PERK, IRE1α, and EIF2α as well as reduced ATF6 and CHOP. Importantly, naringenin significantly activated myocardial cGMP-PKGIα signaling while inhibition of PKG signaling with KT5823 (in vivo) or siRNA (in vitro) not only abolished these actions but also blunted naringenin’s inhibitory effects against oxidative stress and ER stress. In summary, our study demonstrates that naringenin treatment protects against MI/R injury by reducing oxidative stress and ER stress via cGMP-PKGIα signaling. Its cardioprotective effect deserves further clinical study.


2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Haifeng Zhang ◽  
Liming Yu ◽  
Zhenwei Shi ◽  
Weifeng Lv ◽  
Ru Tie ◽  
...  

Diabetes mellitus (DM) increases morbidity/mortality of ischemic heart disease (IHD). Although atrial natriuretic peptide (ANP) and C-type natriuretic peptide (CNP) reduce the myocardial ischemia/reperfusion (MI/R) damage in non-diabetic rats, whether vasonatrin peptide (VNP), the artificial synthetic chimera of ANP and CNP, confers cardioprotective effect against acute MI/R injury, especially in diabetic patients, is still unclear. This study aimed to investigate the effects of VNP on MI/R injury in diabetic rats and the involved mechanisms. The high-fat diet-fed streptozotocin (HFD-STZ) induced diabetic rats were subjected to MI/R (30 min/4 h). VNP treatment (100 µg/kg, i.v., 10 min before R) significantly improved ± LV d P /dt max [(3242 ± 103) and -(2731 ± 79) mm Hg/s vs. (2936 ± 90) and -(2422 ± 83) mm Hg/s in DM group] and LVSP and reduced LVEDP, and reduced infarct size [(43.3 ± 3.6) % vs (53.5 ± 2.8) %], apoptosis index [(36.0 ± 2.1) % vs. (45.7 ± 3.5) %], caspase-3 activity, serum CK and LDH levels (n=8, P <0.05). Moreover, VNP inhibited endoplasmic reticulum (ER) stress by suppressing GRP78 and CHOP (n=3, P <0.05), and consequently increased the antiapoptotic protein Akt and ERK1/2 expression and phosphorylation levels ( P <0.05). These effects were mimicked by 8-Br-cGMP (1 mg/kg, i.p., 20 min before R), a cGMP analogue, whereas inhibited by KT-5823 (0.5 mg/kg, i.p.), the selective inhibitor of PKG (both P <0.05). In addition, pretreated DM rats with TUDCA (50 mg/kg, i.p.), a specific inhibitor of ER stress, couldn’t further promote the VNP’s cardioprotective effect ( P >0.05). In vitro study was performed using H9c2 cardiomyocytes subjected to hypoxia/reoxygenation (H/R, 3 h/6 h) and incubated with or without VNP (10 -8 mol/L). Gene knockdown of PKG1α with siRNA blunted VNP’s inhibition of ER stress and apoptosis (n=6, P <0.05), while overexpression of PKG1α resulted in significant decreased ER stress and apoptosis (n=6, P <0.01). In conclusion, VNP protects diabetic heart against MI/R injury by inhibiting ER stress via cGMP-PKG signaling pathway. These results suggest that VNP may have potential therapeutic value for the diabetic patients with ischemic heart disease.


2021 ◽  
Vol 8 ◽  
Author(s):  
Cuizhi Li ◽  
Huafeng Song ◽  
Chunlin Chen ◽  
Shaoxian Chen ◽  
Qiyu Zhang ◽  
...  

Objective: Myocardial ischemia reperfusion (I/R) damage is a life-threatening vascular emergency after myocardial infarction. Here, we observed the cardioprotective effect of long non-coding RNA (lncRNA) PVT1 knockdown against myocardial I/R damage.Methods: This study constructed a myocardial I/R-induced mouse model and a hypoxia/reoxygenation (H/R)-treated H9C2 cells. PVT1 expression was examined via RT-qPCR. After silencing PVT1 via shRNA against PVT1, H&amp;E, and Masson staining was performed to observe myocardial I/R damage. Indicators of myocardial injury including cTnI, LDH, BNP, and CK-MB were examined by ELISA. Inflammatory factors (TNF-α, IL-1β, and IL-6), Gasdermin D (GSDMD), and Caspase1 were detected via RT-qPCR, western blot, immunohistochemistry, or immunofluorescence. Furthermore, CCK-8 and flow cytometry were presented for detecting cell viability and apoptosis.Results: LncRNA PVT1 was markedly up-regulated in myocardial I/R tissue specimens as well as H/R-induced H9C2 cells. Silencing PVT1 significantly lowered serum levels of cTnI, LDH, BNP, and CK-MB in myocardial I/R mice. H&amp;E and Masson staining showed that silencing PVT1 alleviated myocardial I/R injury. PVT1 knockdown significantly lowered the production and release of inflammatory factors as well as inhibited the expression of GSDMD-N and Caspase1 in myocardial I/R tissue specimens as well as H/R-induced H9C2 cells. Moreover, silencing PVT1 facilitated cell viability and induced apoptosis of H/R-treated H9C2 cells.Conclusion: Our findings demonstrated that silencing PVT1 could alleviate myocardial I/R damage through suppressing GSDMD-mediated pyroptosis in vivo and in vitro. Thus, PVT1 knockdown may offer an alternative therapeutic strategy against myocardial I/R damage.


1998 ◽  
Vol 274 (2) ◽  
pp. R470-R475 ◽  
Author(s):  
Deborah A. Scheuer ◽  
Steven W. Mifflin

Chronic stress in humans has been correlated with increased risk for ischemic heart disease. Thus experiments were conducted to determine if repeated intermittent restraint stress increased infarct size in a rat model of myocardial ischemia-reperfusion injury. Male Sprague-Dawley rats were subjected to no stress (control) or to daily restraint stress for 1–1.5 h for 8–14 days (stress protocol A) or for 2 h daily for 11 or 12 days (stress protocol B). Myocardial ischemia-reperfusion (30-min ischemia, 3-h reperfusion) was performed in anesthetized rats. Average baseline arterial pressures were 111 ± 4, 120 ± 10, and 125 ± 7 mmHg in the control, stress protocol A, and stress protocol B groups, respectively. Infarct size (%area at risk) was significantly larger in both groups of stressed rats compared with control rats (58 ± 5, 78 ± 2, and 79 ± 3% in the control, stress protocol A, and stress protocol B groups, respectively). During ischemia or early reperfusion, zero of eight control, two of six protocol A stress, and two of five protocol B stress rats had at least one period of severe arrhythmia. Therefore, these results provide experimental evidence corroborating correlative studies in humans that link chronic stress with increased morbidity and mortality from ischemic heart disease.


2016 ◽  
Vol 94 (12) ◽  
pp. 1267-1275 ◽  
Author(s):  
Yidan Wei ◽  
Meijuan Xu ◽  
Yi Ren ◽  
Guo Lu ◽  
Yangmei Xu ◽  
...  

Arachidonic acid (AA) is a precursor that is metabolized by several enzymes to many biological eicosanoids. Accumulating data indicate that the ω-hydroxylation metabolite of AA, 20-hydroxyeicosatetraenoic acid (20-HETE), is considered to be involved in the myocardial ischemia–reperfusion injury (MIRI). The inhibitors of AA ω-hydroxylase, however, are demonstrated to exhibit protective effects on MIRI. Dihydrotanshinone I (DI), a bioactive constituent of danshen, is proven to be a potent inhibitor of AA ω-hydroxylase by our preliminary study in vitro. The purpose of the present study was to investigate the cardioprotection of DI against MIRI and its effects on the concentrations of 20-HETE in vivo. Rats subjected to 30 min of ischemia followed by 24 h of reperfusion were assigned to intravenously receive vehicle (sham and ischemia–reperfusion), low (1 mg/kg), middle (2 mg/kg), or high (4 mg/kg) doses of DI before reperfusion. The results demonstrated that DI treatment could improve cardiac function, reduce infarct size, ameliorate the variations in myocardial zymogram and histopathological disorders, decrease 20-HETE generation, and regulate apoptosis-related protein in myocardial ischemia–reperfusion rats. These findings suggested DI could exert considerable cardioprotective action on MIRI by the attenuation of 20-HETE generation, subsequent myocardial injury, and apoptosis through inhibition on AA ω-hydroxylase.


Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4779
Author(s):  
Ying Fu ◽  
Cai Zhao ◽  
Rengui Saxu ◽  
Chaoran Yao ◽  
Lianbo Zhao ◽  
...  

(±)-Anastatins A and B are flavonoids isolated from Anastatica hierochuntica. In a previous study, twenty-four di- and tri-substituted novel derivatives of anastatins were designed and their preliminary antioxidant activities were evaluated. In the present study, the protective effect of myocardial ischemia-reperfusion (I/R) and the systematic antioxidant capacity of 24 derivatives were further studied. Compound 13 was the most potent among all the compounds studied, which increased the survival of H9c2 cells to 80.82%. The antioxidant capability of compound 13 was evaluated in ferric reducing antioxidant power, 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging, and 2,2-diphenyl-1-picrylhydrazyl assays. It was observed that compound 13 significantly reduced infarcted areas and improved histopathological and electrocardiogram changes in rats with myocardial I/R injury. Moreover, compound 13 decreased the leakage rates of serum lactate dehydrogenase, creatine kinase, and malonyldialdehyde from rat myocardial tissues and increased the level of glutathione and superoxide dismutase activities following myocardial I/R injury in rats. Taken together, we concluded that compound 13 had potent cardioprotective effects against myocardial I/R injury both in vitro and in vivo owing to its extensive antioxidant activities.


Sign in / Sign up

Export Citation Format

Share Document