scholarly journals C1q/TNF-Related Protein 9 Protects Diabetic Rat Heart against Ischemia Reperfusion Injury: Role of Endoplasmic Reticulum Stress

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Sanxing Bai ◽  
Liang Cheng ◽  
Yang Yang ◽  
Chongxi Fan ◽  
Dajun Zhao ◽  
...  

As a newly identified adiponectin paralog, C1q/TNF-related protein 9 (CTRP9) reduces myocardial ischemia reperfusion (IR) injury through partially understood mechanisms. In the present study, we sought to identify the role of endoplasmic reticulum stress (ERS) in CTRP9 induced cardioprotection in diabetic heart. Isolated hearts from high-fat-diet (HFD) induced type 2 diabetic Sprague-Dawley rats were subjected to ex vivo IR protocol via a Langendorff apparatus at the presence of globular CTRP9. CTRP9 significantly improved post-IR heart function and reduced cardiac infarction, cardiomyocytes apoptosis, Caspase-3, Caspase-9, Caspase-12, TNF-αexpression, and lactate dehydrogenase activity. The cardioprotective effect of CTRP9 was associated with reduced ERS and increased expression of disulfide-bond A oxidoreductase-like protein (DsbA-L) in diabetic heart. CTRP9 reduced ERS in thapsigargin (TG) treated cardiomyocytes and protected endoplasmic reticulum (ER) stressed H9c2 cells against simulated ischemia reperfusion (SIR) injury, concurrent with increased expression of DsbA-L. Knockdown of DsbA-L increased ERS and attenuated CTRP9 induced protection against SIR injury in H9c2 cells. Our findings demonstrated for the first time that CTRP9 exerts cardioprotection by reducing ERS in diabetic heart through increasing DsbA-L.

2019 ◽  
Vol 97 (5) ◽  
pp. 345-351 ◽  
Author(s):  
Ai-Jie Liu ◽  
Chun-Xia Pang ◽  
Guo-Qiang Liu ◽  
Shi-Duan Wang ◽  
Chun-Qin Chu ◽  
...  

We aimed to investigate whether the cardioprotection of sevoflurane against ischemia–reperfusion (IR) injury is via inhibiting endoplasmic reticulum stress. The rat in vivo model of myocardial IR injury was induced by ligation of the left anterior descending coronary artery. Sevoflurane significantly ameliorated the reduced cardiac function, increased infarct size, and elevated troponin I level and lactate dehydrogenase activity in plasma induced by IR injury. Sevoflurane suppressed the IR-induced myocardial apoptosis. The increased protein levels of glucose-regulated protein 78 and C/EBP homologous protein (CHOP) after myocardial IR were significantly reduced by sevoflurane. The protein levels of phosphorylated protein kinase RNA-like endoplasmic reticulum kinase (PERK), phosphorylated eukaryotic initiation factor 2 (eIF2α), and activating transcription factor 4 (ATF4) were significantly increased in rats with IR and attenuated by sevoflurane treatment. The phosphorylation of Akt was further activated by sevoflurane. The cardioprotection of sevoflurane could be blocked by wortmannin, a PI3K/Akt inhibitor. Our results suggest that the cardioprotection of sevoflurane against IR injury might be mediated by suppressing PERK/eIF2a/ATF4/CHOP signaling via activating the Akt pathway, which helps in understanding the novel mechanism of the cardioprotection of sevoflurane.


2020 ◽  
Author(s):  
Zhipeng Zhu ◽  
Xiaoyan Ling ◽  
Hongmei Zhou ◽  
Caijun Zhang

BackgroundMyocardial ischemia-reperfusion injury (MIRI) has been confirmed to induce endoplasmic reticulum stress(ERS) during downstream cascade reaction when myocardial cell function keep deteriorating to a certain degree. The fact of matter is the clinical inconsistence with experimental outcomes still exist due to the mechanism has not been entirely clarified. Dexmedetomidine (DEX), a new generation anti-inflammatory and organ protector, has been testified can attenuate the IRI of heart. This study aimed to find out if DEX had the capacity to protect the injured cardiomyocytes under in vitro hypoxia/reoxygenation circumstance and if the ERS was totally or partly intervened.MethodsH9C2 cells were subjected to cytotoxicity detection for 24h with DEX normally cultivated in several different concentrations. The proper hypoxia/reoxygenation (H/R) model parameter were concluded by the cell viability and injuries by cell counting kit-8(CCK8) and lactate dehydrogenase (LDH) release, when undergoing hypoxic condition for 3 h and reoxygenated for 3h, 6h,12h, and 24h, respectively. Also, the above index was assessed for H/R cardiomyocytes cultivated by various concentrations of DEX. The apoptosis, expression of) Glucose-regulated protein 78(GRP78), C/EBP homologous protein (CHOP), and caspase-12 were also examined in all groups.Results1, 5 and 10 μM DEX in normal culture could significantly promote the proliferation of H9C2 (> 80%); the activity of H9c2 cells decreased to 62.67% (P < 0.05) at 3h of reoxygenation and to 36% at 6h of reoxygenation followed by 3h anoxic treatment; The cell viability of H9c2 cells in H/R groups incubated with 1 μM DEX increased 61.3%, and the LDH concentration in the supernatant was effectively lowered (−13.7, P < 0.05); H/R dramatically decreased the proportion of flow cytometry apoptosis and increased the expression of GRP78, CHOP and caspase-12, while both DEX and 4-phenyl butyric acid (4-PBA) could significantly reverse those above indicators. Additionally, DEX could induce deeper alterations than 4-PBA on the basis of H/R.Conclusion1 μM DEX can dramatically attended the cell injuries, apoptosis, the expression of GRP78, CHOP and caspase-12 of H9C2 induced by 3h’ hypoxia and 3h’s reoxygenation. moreover, the functions of DEX went beyond the inhibition of ERS under this situation.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Bonan Hou ◽  
Rui Liu ◽  
You Wu ◽  
Shuiqing Huang

Background. Previous studies proved that AS-IV could prevent blood-brain barrier (BBB) against an increase in permeability. However, its underlying molecular mechanism has not been enlightened yet. The aim of the study is to reveal the potential protective mechanism of astragaloside IV (AS-IV) on the blood-brain barrier after ischemia-reperfusion. Methods. In vivo, AS-IV neurological protection was measured by Long’s five-point scale and 2,3,5-triphenyltetrazolium chloride staining. AS-IV protection for BBB was observed by Evans blue extravasation technique. Endoplasmic reticulum stress and apoptosis-related protein levels were measured by western blot with AS-IV intervention. In vitro, cell apoptosis was analyzed by western blot and flow cytometry.Endoplasmic reticulum stress-related protein levels were quantified through western blot. Results. AS-IV treatment could decrease the infarct size in rats’ brain and protect the BBB against Evans blue permeating through brain, after ischemia/reperfusion, significantly. Further, ischemia/reperfusion or oxygen‐glucose deprivation/reperfusion was found to have an increase in endothelial cell apoptosis proteins, such as Bax, Bcl-2, and caspase-3, and endoplasmic reticulum stress-associated proteins, such as phosphorylated PERK and eIF2α, Bip, and CHOP, which were attenuated by AS-IV treatment. Conclusions. AS-IV can effectively protect the blood-brain barrier and reduce the area of cerebral infarction via inhibiting endoplasmic reticulum stress-mediated apoptosis in endothelial cells.


2007 ◽  
Vol 196 (3) ◽  
pp. 565-572 ◽  
Author(s):  
Zhenhua Li ◽  
Tao Zhang ◽  
Hongyan Dai ◽  
Guanghui Liu ◽  
Haibin Wang ◽  
...  

Apoptosis plays a critical role in the diabetic cardiomyopathy, and endoplasmic reticulum stress (ERS) is one of the intrinsic apoptosis pathways. Previous studies have shown that the endoplasmic reticulum becomes swollen and dilated in diabetic myocardium, and ERS is involved in heart failure and diabetic kidney. This study is aimed to demonstrate whether ERS is induced in myocardium of streptozotocin (STZ)-induced diabetic rats. We established a type 1 diabetic rat model, used echocardiographic evaluation, hematoxylin–eosin staining, and the terminal deoxynucleotidyl transferase-mediated DNA nick-end labeling staining to identify the existence of diabetic cardiomyopathy and enhanced apoptosis in the diabetic heart. We performed immunohistochemistry, western blot, and real-time PCR to analyze the hallmarks of ERS that include glucose-regulated protein 78, CCAAT/enhancer-binding protein homologous protein (CHOP) and caspase12. We found these hallmarks to have enhanced expression in protein and mRNA levels in diabetic myocardium. Also, another pathway that can lead to cell death of ERS, c-Jun NH2-terminal kinase-dependent pathway, was also activated in diabetic heart. Those results suggested that ERS was induced in STZ-induced diabetic rats' myocardium, and ERS-associated apoptosis occurred in the pathophysiology of diabetic cardiomyopathy.


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