Crosstalk Between Oxidative Stress and Endoplasmic Reticulum (ER) Stress in Endothelial Dysfunction and Aberrant Angiogenesis Associated With Diabetes: A Focus on the Protective Roles of Heme Oxygenase (HO)-1

The vascular complications of diabetes mellitus impose a huge burden on the management of this disease. The higher incidence of cardiovascular complications and the unfavorable prognosis among diabetic individuals who develop such complications have been correlated to the hyperglycemia-induced oxidative stress and associated endothelial dysfunction. Although antioxidants may be considered as effective therapeutic agents to relieve oxidative stress and protect the endothelium, recent clinical trials involving these agents have shown limited therapeutic efficacy in this regard. In the recent past experimental evidence suggest that endoplasmic reticulum (ER) stress in the endothelial cells might be an important contributor to diabetes-related vascular complications. The current paper contemplates the possibility of the involvement of ER stress in endothelial dysfunction and diabetes-associated vascular complications.

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Abstract 357: Hepatic ERK2 Suppresses Endoplasmic Reticulum Stress, Leading to Protection from Oxidative Stress and Endothelial Dysfunction

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.33.suppl_1.a357 ◽

2013 ◽

Vol 33 (suppl_1) ◽

Author(s):

Takehiko Kujiraoka ◽

Yasushi Satoh ◽

Makoto Ayaori ◽

Yasunaga Shiraishi ◽

Yuko Arai-Nakaya ◽

...

Keyword(s):

Oxidative Stress ◽

Insulin Resistance ◽

Endoplasmic Reticulum ◽

Fatty Acid ◽

Endothelial Dysfunction ◽

Er Stress ◽

Vascular Complications ◽

Metabolic Remodeling ◽

And Oxidative Stress

Background Insulin signaling comprises 2 major cascades, the IRS/PI3K/Akt and Ras/Raf/MEK/ERK pathways. Many studies on the tissue-specific effects of the former pathway had been conducted, however, the role of the latter cascade in tissue-specific insulin resistance had not been investigated. High glucose/fatty acid toxicity, inflammation and oxidative stress, all of which are associated with insulin resistance, can activate ERK. Liver plays a central role of metabolism and hepatosteatosis (HST) is associated with vascular diseases. The aim of this study is to elucidate the role of hepatic ERK2 in HST, metabolic remodeling and endothelial dysfunction. Methods Serum biomarkers of vascular complications in human were compared between subjects with and without HST diagnosed by echography for regular medical checkup. Next, we created liver-specific ERK2 knockout mice (LE2KO) and fed them with a high-fat/high-sucrose diet (HFHSD) for 20 weeks. The histological analysis, the expression of hepatic sarco/endoplasmic reticulum (ER) Ca 2+ -ATPase 2 (SERCA2) and glucose-tolerance/insulin-sensitivity (GT/IS) were tested. Vascular superoxide production and endothelial function were evaluated with dihydroethidium staining and isometric tension measurement of aorta. Results The presence of HST significantly increased HOMA-IR, an indicator of insulin resistance or atherosclerotic index in human. HFHSD-fed LE2KO revealed a marked exacerbation in HST and metabolic remodeling represented by the impairment of GT/IS, elevated serum free fatty acid and hyperhomocysteinemia without changes in body weight, blood pressure and serum cholesterol/triglyceride levels. In the HFHSD-fed LE2KO, mRNA and protein expressions of hepatic SERCA2 were significantly decreased, which resulted in hepatic ER stress. Induction of vascular superoxide production and remarkable endothelial dysfunction were also observed in them. Conclusions Hepatic ERK2 revealed the suppression of hepatic ER stress and HST in vivo , which resulted in protection from vascular oxidative stress and endothelial dysfunction. HST with hepatic ER stress can be a prominent risk of vascular complications by metabolic remodeling and oxidative stress in obese-related diseases.

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Testicular Injury Attenuated by Rapamycin Through Induction of Autophagy and Inhibition of Endoplasmic Reticulum Stress in Streptozotocin- Induced Diabetic Rats

Endocrine Metabolic & Immune Disorders - Drug Targets ◽

10.2174/1871530319666190102112844 ◽

2019 ◽

Vol 19 (5) ◽

pp. 665-675 ◽

Cited By ~ 4

Author(s):

Wenjiao Shi ◽

Zhixin Guo ◽

Ruixia Yuan

Keyword(s):

Oxidative Stress ◽

Endoplasmic Reticulum ◽

Endoplasmic Reticulum Stress ◽

Protective Effect ◽

Er Stress ◽

B Cell Lymphoma ◽

Diabetic Rats ◽

Pathological Changes ◽

Rapamycin Treatment ◽

Related Proteins

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.

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Coptisine Attenuates Diabetes—Associated Endothelial Dysfunction through Inhibition of Endoplasmic Reticulum Stress and Oxidative Stress

Molecules ◽

10.3390/molecules26144210 ◽

2021 ◽

Vol 26 (14) ◽

pp. 4210

Author(s):

Yan Zhou ◽

Chunxiu Zhou ◽

Xutao Zhang ◽

Chi Teng Vong ◽

Yitao Wang ◽

...

Keyword(s):

Oxidative Stress ◽

Risk Factors ◽

Endoplasmic Reticulum ◽

Er Stress ◽

Vascular Function ◽

Inflammatory Responses ◽

Therapeutic Potential ◽

Ex Vivo ◽

Diabetic Mice ◽

And Oxidative Stress

Coptisine is the major bioactive protoberberine alkaloid found in Rhizoma Coptidis. Coptisine reduces inflammatory responses and improves glucose tolerance; nevertheless, whether coptisine has vasoprotective effect in diabetes is not fully characterized. Conduit arteries including aortas and carotid arteries were obtained from male C57BL/6J mice for ex vivo treatment with risk factors (high glucose or tunicamycin) and coptisine. Some arterial rings were obtained from diabetic mice, which were induced by high-fat diet (45% kcal% fat) feeding for 6 weeks combined with a low-dose intraperitoneal injection of streptozotocin (120 mg/kg). Functional studies showed that coptisine protected endothelium-dependent relaxation in aortas against risk factors and from diabetic mice. Coptisine increased phosphorylations of AMPK and eNOS and downregulated the endoplasmic reticulum (ER) stress markers as determined by Western blotting. Coptisine elevates NO bioavailability and decreases reactive oxygen species level. The results indicate that coptisine improves vascular function in diabetes through suppression of ER stress and oxidative stress, implying the therapeutic potential of coptisine to treat diabetic vasculopathy.

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Crosstalk between endoplasmic reticulum stress and oxidative stress: a dynamic duo in multiple myeloma

Cellular and Molecular Life Sciences ◽

10.1007/s00018-021-03756-3 ◽

2021 ◽

Author(s):

Sinan Xiong ◽

Wee-Joo Chng ◽

Jianbiao Zhou

Keyword(s):

Oxidative Stress ◽

Multiple Myeloma ◽

Endoplasmic Reticulum ◽

Er Stress ◽

Cell Fate ◽

Stress Responses ◽

Plasma Cells ◽

Reactive Oxygen Species Generation ◽

Future Research ◽

And Oxidative Stress

AbstractUnder physiological and pathological conditions, cells activate the unfolded protein response (UPR) to deal with the accumulation of unfolded or misfolded proteins in the endoplasmic reticulum. Multiple myeloma (MM) is a hematological malignancy arising from immunoglobulin-secreting plasma cells. MM cells are subject to continual ER stress and highly dependent on the UPR signaling activation due to overproduction of paraproteins. Mounting evidence suggests the close linkage between ER stress and oxidative stress, demonstrated by overlapping signaling pathways and inter-organelle communication pivotal to cell fate decision. Imbalance of intracellular homeostasis can lead to deranged control of cellular functions and engage apoptosis due to mutual activation between ER stress and reactive oxygen species generation through a self-perpetuating cycle. Here, we present accumulating evidence showing the interactive roles of redox homeostasis and proteostasis in MM pathogenesis and drug resistance, which would be helpful in elucidating the still underdefined molecular pathways linking ER stress and oxidative stress in MM. Lastly, we highlight future research directions in the development of anti-myeloma therapy, focusing particularly on targeting redox signaling and ER stress responses.

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Molecular functions of ASK family in diseases caused by stress-induced inflammation and apoptosis

The Journal of Biochemistry ◽

10.1093/jb/mvaa145 ◽

2020 ◽

Author(s):

Kazuki Kojima ◽

Hidenori Ichijo ◽

Isao Naguro

Keyword(s):

Oxidative Stress ◽

Endoplasmic Reticulum ◽

Adverse Effects ◽

Er Stress ◽

Inflammatory Diseases ◽

Family Members ◽

Disease States ◽

Molecular Functions ◽

Critical Responses ◽

Proper Response

Summary VCells are constantly exposed to various types of stress, and disruption of the proper response lead to a variety of diseases. Among them, inflammation and apoptosis are important examples of critical responses and should be tightly regulated, as inappropriate control of these responses is detrimental to the organism. In several disease states, these responses are abnormally regulated, with adverse effects. Apoptosis signal-regulating kinase (ASK) family members are stress-responsive kinases that regulate inflammation and apoptosis after a variety of stimuli, such as oxidative stress and endoplasmic reticulum (ER) stress. In this review, we summarize recent reports on the ASK family in terms of their involvement in inflammatory diseases, focusing on upstream stimuli that regulate ASK family members.

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PERK mediates oxidative stress and adipogenesis in Graves’ orbitopathy pathogenesis

Journal of Molecular Endocrinology ◽

10.1530/jme-21-0057 ◽

2021 ◽

Author(s):

JaeSang Ko ◽

Ji-Young Kim ◽

Min Kyung Chae ◽

Eun Jig Lee ◽

Jin Sook Yoon

Keyword(s):

Oxidative Stress ◽

Hydrogen Peroxide ◽

Endoplasmic Reticulum ◽

Transcription Factor ◽

Er Stress ◽

Adipogenic Differentiation ◽

Ros Generation ◽

Mrna Levels ◽

Graves Orbitopathy ◽

Orbital Fibroblasts

We examined endoplasmic reticulum (ER) stress-related gene expression in orbital tissues from patients with Graves’ orbitopathy (GO) and the effects of silencing protein kinase RNA-like endoplasmic reticulum kinase (PERK) in primary orbital fibroblast cultures to demonstrate the therapeutic potential of PERK-modulating agents in GO management. The expression of ER stress related genes in orbital tissue harvested from individuals with or without GO was studied using real-time polymerase chain reaction. The role of PERK in GO pathogenesis was examined through small-interfering RNA (siRNA)-mediated silencing in cultured primary orbital fibroblasts. Intracellular reactive oxygen species (ROS) levels induced in response to cigarette smoke extract (CSE) or hydrogen peroxide were measured using 5-(and 6)-carboxy-20,70-dichlorodihydrofluorescein diacetate staining and flow cytometry. Cells were stained with Oil Red O, and adipogenesis-related transcription factor expression was evaluated through western blotting after adipogenic differentiation. PERK, activating transcription factor 4 (ATF4), and CCAAT-enhancer-binding protein (C/EBP)-homologous protein(CHOP)mRNA levels were significantly higher in GO orbital tissues than in non-GO orbital tissues. PERK silencing inhibited CSE- or hydrogen peroxide-induced ROS generation. After adipogenic differentiation, GO orbital fibroblasts revealed decreased lipid droplets and downregulation of C/EBPα, C/EBPβ, and peroxisome proliferator-activator gamma (PPARγ) in PERK siRNA-transfected cells. The orbital tissues of patients with GO were exposed to chronic ER stress and subsequently exhibited enhanced unfolded protein response (especially through the PERK pathway). PERK silencing reduced oxidative stress and adipogenesis in GO orbital fibroblasts in vitro. Our results imply that PERK-modulating agents can potentially be used to manage GO.

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Hydrogen sulfide alleviates hyperhomocysteinemia-mediated skeletal muscle atrophy via mitigation of oxidative and endoplasmic reticulum stress injury

AJP Cell Physiology ◽

10.1152/ajpcell.00147.2018 ◽

2018 ◽

Vol 315 (5) ◽

pp. C609-C622 ◽

Cited By ~ 17

Author(s):

Avisek Majumder ◽

Mahavir Singh ◽

Jyotirmaya Behera ◽

Nicholas T. Theilen ◽

Akash K. George ◽

...

Keyword(s):

Oxidative Stress ◽

Skeletal Muscle ◽

Endoplasmic Reticulum ◽

Hydrogen Sulfide ◽

Er Stress ◽

Muscle Atrophy ◽

C2c12 Cells ◽

Skeletal Muscle Atrophy ◽

Stress Injury ◽

Western Blots

Although hyperhomocysteinemia (HHcy) occurs because of the deficiency in cystathionine-β-synthase (CBS) causing skeletal muscle dysfunction, it is still unclear whether this effect is mediated through oxidative stress, endoplasmic reticulum (ER) stress, or both. Nevertheless, there is no treatment option available to improve HHcy-mediated muscle injury. Hydrogen sulfide (H2S) is an antioxidant compound, and patients with CBS mutation do not produce H2S. In this study, we hypothesized that H2S mitigates HHcy-induced redox imbalance/ER stress during skeletal muscle atrophy via JNK phosphorylation. We used CBS+/−mice to study HHcy-mediated muscle atrophy, and treated them with sodium hydrogen sulfide (NaHS; an H2S donor). Proteins and mRNAs were examined by Western blots and quantitative PCR. Proinflammatory cytokines were also measured. Muscle mass and strength were studied via fatigue susceptibility test. Our data revealed that HHcy was detrimental to skeletal mass, particularly gastrocnemius and quadriceps muscle weight. We noticed that oxidative stress was reversed by NaHS in homocysteine (Hcy)-treated C2C12 cells. Interestingly, ER stress markers (GRP78, ATF6, pIRE1α, and pJNK) were elevated in vivo and in vitro, and NaHS mitigated these effects. Additionally, we observed that JNK phosphorylation was upregulated in C2C12 after Hcy treatment, but NaHS could not reduce this effect. Furthermore, inflammatory cytokines IL-6 and TNF-α were higher in plasma from CBS as compared with wild-type mice. FOXO1-mediated Atrogin-1 and MuRF-1 upregulation were attenuated by NaHS. Functional studies revealed that NaHS administration improved muscle fatigability in CBS+/−mice. In conclusion, our work provides evidence that NaHS is beneficial in mitigating HHcy-mediated skeletal injury incited by oxidative/ER stress responses.

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Fenofibrate Ameliorates Insulin Resistance of Lipoprotein Lipase Knockout Heterozygous Mice

10.21203/rs.2.22680/v1 ◽

2020 ◽

Author(s):

Yangxue Li ◽

Tingting Han ◽

Shuang Zheng ◽

Xingxing Ren ◽

Yaomin Hu

Keyword(s):

Oxidative Stress ◽

Insulin Resistance ◽

Skeletal Muscle ◽

Endoplasmic Reticulum ◽

Glucose Tolerance ◽

Er Stress ◽

Lipid Profile ◽

Lipoprotein Lipase ◽

Peroxisome Proliferator ◽

Phosphorylated Akt

Abstract Background The benefits of fenofibrate (FB), a peroxisome proliferator-activated receptor-a agonist, against hyperlipidemia have been established. We investigated the effect of fenofibrate on insulin resistance of lipoprotein lipase knockout heterozygous (LPL+/-) mice, which represent inherited hypertriglyceridemia and impaired glucose tolerance. Methods Male LPL+/- mice were treated with FB (50 mg/kg, once daily) via gavage for 8 weeks. Plasma lipid, glucose tolerance test, systemic insulin sensitivity, insulin signaling of tissues, genes and proteins related to endoplasmic reticulum (ER) stress and oxidative stress were analyzed. Results Body weight of 40-week LPL+/- with FB were reduced by 30.3% (P<0.05), while the differences of 16- and 28-week LPL+/- with FB were not significant (P>0.05). FB improved the lipid profile of both 28 and 40-week LPL+/- (P<0.001 for both), while that of 16-week LPL+/- mice with FB was unaltered (P>0.05). Glucose tolerance of 40-week LPL+/- were improved by FB (P<0.05), while that of 16- and 28-week LPL+/- with FB kept unaltered (P>0.05). Fasting insulin of 40-week LPL +/- were improved by FB (P<0.05), thus HOMA-IR of 40-week LPL+/- was declined (P<0.05). HOMA-IR of 16- and 28-week LPL+/- with FB had no change. Insulin-stimulated phosphorylated Akt (Ser473) in liver and skeletal muscle of 28-week LPL+/- was enhanced by FB (P < 0.001 and P<0.05 respectively). ER stress biomarkers were detected decreased in liver of 16- to 40-week LPL+/- with FB whereas that in muscle of LPL+/- with FB unchanged. Reduced reactive oxygen species (ROS) levels and augmented mRNA expression of superoxide dismutase (SOD) and catalase (CAT) in skeletal muscle of 28- and 40-week LPL+/- mice with FB were observed. There was no significance on ROS levels and mRNA of SOD and CAT in liver between LPL+/- mice with and without FB. Conclusions Fenofibrate improved lipid profile, glucose tolerance, systemic and tissue-specific insulin resistance of LPL knockout heterozygous mice. This may be associated with alleviated endoplasmic reticulum stress in liver and reduced oxidative stress in muscle.

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