scholarly journals Endoplasmic reticulum stress is involved in myocardial apoptosis of streptozocin-induced diabetic rats

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.

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Shu Yan ◽  
Cui Zheng ◽  
Zhi-qi Chen ◽  
Rong Liu ◽  
Gui-gang Li ◽  
...  

Recent reports show that ER stress plays an important role in diabetic retinopathy (DR), but ER stress is a complicated process involving a network of signaling pathways and hundreds of factors, What factors involved in DR are not yet understood. We selected 89 ER stress factors from more than 200, A rat diabetes model was established by intraperitoneal injection of streptozotocin (STZ). The expression of 89 ER stress-related factors was found in the retinas of diabetic rats, at both 1- and 3-months after development of diabetes, by quantitative real-time polymerase chain reaction arrays. There were significant changes in expression levels of 13 and 12 ER stress-related factors in the diabetic rat retinas in the first and third month after the development of diabetes, Based on the array results, homocysteine- inducible, endoplasmic reticulum stress-inducible, ubiquitin-like domain member 1(HERP), and synoviolin(HRD1) were studied further by immunofluorescence and Western blot. Immunofluorescence and Western blot analyses showed that the expression of HERP was reduced in the retinas of diabetic rats in first and third month. The expression of Hrd1 did not change significantly in the retinas of diabetic rats in the first month but was reduced in the third month.


2017 ◽  
Vol 41 (6) ◽  
pp. 2503-2512 ◽  
Author(s):  
Yang Zhou ◽  
Wei Wu

Background/Aims: This study aimed to determine whether or not the sodium-glucose co-transporter 2 inhibitor, empagliflozin (EMPA), can protect against diabetic cardiomyopathy (DCM) and to elucidate the related mechanism. Methods: Rats were divided into the following four groups: a non-diabetic group; diabetic cardiomyopathy rats without EMPA treatment; and diabetic cardiomyopathy rats with EMPA treatment (low- and high-dose EMPA). Hemodynamic measurements were performed to evaluate left ventricular systolic and diastolic function. The histopathology of the heart was examined with hematoxylin-eosin staining. Expression of glucose-regulated protein (GRP)78, enhancer-binding protein homologous protein (CHOP), and caspase-12 was detected by Western blot, and the mRNA levels of XBP1, ATF4, and TRAF2 were analysed by real-time PCR. Results: EMPA significantly decreased the blood glucose level when compared with vehicle. EMPA strongly improved cardiac function based on hemodynamic and histopathologic analyses. Moreover, EMPA can significantly down-regulate the expression of GRP78, CHOP, and caspase-12 (P < 0.01). Additionally, the mRNA levels of XBP1, ATF4, and TRAF2 were markedly decreased by administration of EMPA (P < 0.01). Conclusion: EMPA protects against DCM by inactivating the endoplasmic reticulum stress pathway.


Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 2182-PUB
Author(s):  
YAN XIONG ◽  
YULIAN HE ◽  
WEI-JIN FANG ◽  
YANPING LEI ◽  
YUAN LIN ◽  
...  

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 19 (5) ◽  
pp. 665-675 ◽  
Author(s):  
Wenjiao Shi ◽  
Zhixin Guo ◽  
Ruixia Yuan

Background and Objective: This study investigated whether rapamycin has a protective effect on the testis of diabetic rats by regulating autophagy, endoplasmic reticulum stress, and oxidative stress. Methods: Thirty male Sprague-Dawley rats were randomly divided into three groups: control, diabetic, and diabetic treated with rapamycin, which received gavage of rapamycin (2mg.kg-1.d-1) after induction of diabetes. Diabetic rats were induced by intraperitoneal injection of streptozotocin (STZ, 65mg.Kg-1). All rats were sacrificed at the termination after 8 weeks of rapamycin treatment. The testicular pathological changes were determined by hematoxylin and eosin staining. The protein or mRNA expression of autophagy-related proteins (Beclin1, microtubule-associated protein light chain 3 (LC3), p62), ER stress marked proteins (CCAAT/enhancer-binding protein (C/EBP) homologous protein (CHOP), caspase-12), oxidative stress-related proteins (p22phox, nuclear factor erythroid2-related factor 2 (Nrf2)) and apoptosis-related proteins (Bax, B cell lymphoma-2 (Bcl-2)) were assayed by western blot or real-time fluorescence quantitative PCR. Results: There were significant pathological changes in the testes of diabetic rats. The expression of Beclin1, LC3, Nrf2, Bcl-2 were significantly decreased and p62, CHOP, caspase12, p22phox, and Bax were notably increased in the testis of diabetic rats (P <0.05). However, rapamycin treatment for 8 weeks significantly reversed the above changes in the testis of diabetic rats (P <0.05). Conclusion: Rapamycin appears to produce a protective effect on the testes of diabetic rats by inducing the expression of autophagy and inhibiting the expression of ER-stress, oxidative stress, and apoptosis.


2005 ◽  
Vol 23 (2) ◽  
pp. 192-205 ◽  
Author(s):  
Chris J. Sullivan ◽  
Thomas H. Teal ◽  
Ian P. Luttrell ◽  
Khoa B. Tran ◽  
Mette A. Peters ◽  
...  

To investigate the full range of molecular changes associated with erectile dysfunction (ED) in Type 1 diabetes, we examined alterations in penile gene expression in streptozotocin-induced diabetic rats and littermate controls. With the use of Affymetrix GeneChip arrays and statistical filtering, 529 genes/transcripts were considered to be differentially expressed in the diabetic rat cavernosum compared with control. Gene Ontology (GO) classification indicated that there was a decrease in numerous extracellular matrix genes (e.g., collagen and elastin related) and an increase in oxidative stress-associated genes in the diabetic rat cavernosum. In addition, PubMatrix literature mining identified differentially expressed genes previously shown to mediate vascular dysfunction [e.g., ceruloplasmin ( Cp), lipoprotein lipase, and Cd36] as well as genes involved in the modulation of the smooth muscle phenotype (e.g., Kruppel-like factor 5 and chemokine C-X3-C motif ligand 1). Real-time PCR was used to confirm changes in expression for 23 relevant genes. Further validation of Cp expression in the diabetic rat cavernosum demonstrated increased mRNA levels of the secreted and anchored splice variants of Cp. CP protein levels showed a 1.9-fold increase in tissues from diabetic rats versus controls. Immunohistochemistry demonstrated localization of CP protein in cavernosal sinusoids of control and diabetic animals, including endothelial and smooth muscle layers. Overall, this study broadens the scope of candidate genes and pathways that may be relevant to the pathophysiology of diabetes-induced ED as well as highlights the potential complexity of this disorder.


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