scholarly journals HADC regulates the diabetic vascular endothelial dysfunction by targetting MnSOD

2018 ◽  
Vol 38 (5) ◽  
Author(s):  
Qian Hou ◽  
Ke Hu ◽  
Xiaofeng Liu ◽  
Jiao Quan ◽  
Zehao Liu

Vascular dysfunction is a common result of diabetes in humans. However, the mechanism underlying diabetic vascular dysfunction is not fully understood. Here in the present study, we showed that the histone deacetylase 2 (HDAC2) promoted the endothelial dysfunction induced by diabetes. The expression and activity of HDAC2 were up-regulated in vascular endothelial cells (ECs) from diabetic patients and mice. The expression of HDAC2 was also increased by high glucose stress in isolated human ECs. HDAC2 knockdown repressed the proliferation rate and promoted high glucose-induced apoptosis of ECs, which was associated with the activation of apoptotic pathways (Bcl-2, Caspase 3, and Bax). By contrast, HDAC2 overexpression led to opposing results. Significantly, we observed that HDAC2 regulated the accumulation of reactive oxygen species (ROS) induced by high glucose in ECs, which accounted for the effects of HDAC2 on proliferation and apoptosis because antioxidants, N-acetyl-l-cysteine (NAC) or MnTBAP treatment blocked the effects of HDAC2 on apoptosis of ECs under high glucose condition. Mechanism study revealed that HDAC2 bound to the promoter of MnSOD and repressed the expression of MnSOD by regulating the level of acetylated H3K9 and H3K27, which led to the promotion of oxidative stress and contributed to the function of HDAC2 in ECs under high glucose condition. Altogether, our evidence demonstrated that HDAC2-MnSOD signaling was critical in oxidative stress and proliferation as well as the survival of ECs under high glucose condition.

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Santosh Kumar ◽  
Young Rae Kim ◽  
Ajit Vikram ◽  
Asma Naqvi ◽  
Ajay Kumar ◽  
...  

The SIRTUIN1 lysine deacetylase (SIRT1) ameliorates diabetic vascular dysfunction by epigenetically suppressing endothelial expression of the oxidative stress protein p66shc. However, whether SIRT1 modulates the oxidative function of p66shc by directly targeting it for lysine deacetylation is not known. Here we show that the oxidative function of p66shc is dynamically modulated by lysine acetylation. Mass spectroscopy identified lysine 81 in the unique CH2 domain of p66shc as the residue targeted by SIRT1. High glucose and SIRT1 knockdown stimulates acetylation of lysine 81 of endothelial p66shc. Compared to WT p66shc, non-acetylatable (K81R) p66shc is significantly handicapped in promoting endothelial hydrogen peroxide production stimulated by high glucose. Compared to WT p66shc, K81R p66shc is also less prone to serine 36 phosphorylation by high glucose, which is essential for the oxidative function of p66shc. Moreover, in contrast to WT p66shc which worsens endothelial dysfunction, expression of K81R p66shc does not impair endothelial function in wild type mice and rescues endothelium dysfunction of diabetic db+/db+ mouse aortas . These findings show that lysine 81 acetylation promotes the oxidative role of p66shc in hyperglycemic conditions, and is essential for p66shc-mediated endothelial dysfunction.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Miao Chen ◽  
Dian Jing ◽  
Rui Ye ◽  
Jianru Yi ◽  
Zhihe Zhao

Abstract Background Diabetic patients are more vulnerable to skeletal complications. Peroxisome proliferators-activated receptor (PPAR) β/δ has a positive regulatory effect on bone turnover under physiologic glucose concentration; however, the regulatory effect in diabetes mellitus has not been investigated yet. Herein, we explored the effects of PPARβ/δ agonist on the regeneration of diabetic bone defects and the osteogenic differentiation of rat bone marrow mesenchymal stem cells (rBMSCs) under a pathological high-glucose condition. Methods We detected the effect of PPARβ/δ agonist on osteogenic differentiation of rBMSCs in vitro and investigated the bone healing process in diabetic rats after PPARβ/δ agonist treatment in vivo. RNA sequencing was performed to detect the differentially expressed genes and enriched pathways. Western blot was performed to detect the autophagy-related protein level. Laser confocal microscope (LSCM) and transmission electron microscope (TEM) were used to observe the formation of autophagosomes. Results Our results demonstrated that the activation of PPARβ/δ can improve the osteogenic differentiation of rBMSCs in high-glucose condition and promote the bone regeneration of calvarial defects in diabetic rats, while the inhibition of PPARβ/δ alleviated the osteogenic differentiation of rBMSCs. Mechanistically, the activation of PPARβ/δ up-regulates AMPK phosphorylation, yielding mTOR suppression and resulting in enhanced autophagy activity, which further promotes the osteogenic differentiation of rBMSCs in high-glucose condition. The addition of AMPK inhibitor Compound C or autophagy inhibitor 3-MA inhibited the osteogenesis of rBMSCs in high-glucose condition, suggesting that PPARβ/δ agonist promotes osteogenic differentiation of rBMSCs through AMPK/mTOR-regulated autophagy. Conclusion In conclusion, our study demonstrates the potential role of PPARβ/δ as a molecular target for the treatment of impaired bone quality and delayed bone healing in diabetic patients for the first time.


2021 ◽  
Vol 28 ◽  
Author(s):  
Olga Simó-Servat ◽  
Hugo Ramos ◽  
Patricia Bogdanov ◽  
Marta García-Ramírez ◽  
Jordi Huerta ◽  
...  

Background: Ezrin, radixin, and moesin (the ERM complex) interact directly with membrane proteins regulating their attachment to actin filaments. ERM protein activation modifies cytoskeleton organization and alters the endothelial barrier function, thus favoring vascular leakage. However, little is known regarding the role of ERM proteins in diabetic retinopathy (DR). Objective: This study aimed to examine whether overexpression of the ERM complex exists in db/db mice and its main regulating factors. Methods: 9 male db/db mice and 9 male db/+ aged 14 weeks were analyzed. ERM proteins were assessed by western blot and by immunohistochemistry. Vascular leakage was determined by the Evans blue method. To assess ERM regulation, HRECs were cultured in a medium containing 5.5 mM D-glucose (mimicking physiological conditions) and 25 mM D-glucose (mimicking hyperglycemia that occurs in diabetic patients). Moreover, treatment with TNF-α, IL-1β, or VEGF was added to a high glucose condition. The expression of ERM proteins was quantified by RT-PCR. Cell permeability was evaluated by measuring movements of FITC-dextran. Results: A significant increase of ERM in diabetic mice in comparison with non-diabetic mice was observed. A high glucose condition alone did not have any effect on ERM expression. However, TNF-α and IL-1β induced a significant increase in ERM proteins. Conclusion: The increase of ERM proteins induced by diabetes could be one of the mechanisms involved in vascular leakage and could be considered as a therapeutic target. Moreover, the upregulation of the ERM complex by diabetes is induced by inflammatory mediators rather than by high glucose itself.


2018 ◽  
Vol 11 (9) ◽  
pp. e201700289 ◽  
Author(s):  
Zahra Ghanian ◽  
Shima Mehrvar ◽  
Nasim Jamali ◽  
Nader Sheibani ◽  
Mahsa Ranji

2018 ◽  
Vol 38 (5) ◽  
Author(s):  
Ying Feng ◽  
Ming-yue Jin ◽  
Dong-wei Liu ◽  
Li Wei

A common complication of both type I and type II diabetes is nephropathy, characterized by accumulation of extracellular matrix in the glomerular mesangium. This indicates a central role of mesangial cells in the pathophysiology of diabetic nephropathy. Using the proteomic approach, it was earlier elucidated in a rat model that the proteasome subunit-α type-6 protein (PSMA6) is suppressed in the renal cortex in nephropathic kidney. However, the underlying mechanism effecting suppression of PSMA6 protein in the renal cortex is not yet known. Twenty diabetic patients were enrolled and the expression level of PSMA6 in them was detected by immunohistochemistry. The protein and mRNA expression levels of PSMA6 in NRK-52E cells under high glucose condition were determined by Western blot and quantitative real-time PCR, respectively. Dual luciferase assay was used to detect the relationship of PSMA6 and miR-4490. Our results show that PSMA6 protein is down-regulated in patients with diabetic nephropathy compared with healthy control. Using the NRK-52E cell line cultured under high glucose condition as an in vitro model of diabetic nephropathy, we show that loss of PSMA6 protein expression occured independent of changes the in PSMA6 mRNA expression. We next elucidate that PSMA6 mRNA is post-transcriptionally regulated by the microRNA (miRNA)-4490, whose expression is inversely correlated to PSMA6 protein expression. Using reporter assays we show that PSMA6 is a direct target of the miR-4490. Exogenous manipulation of miR-4490 levels modulated expression of PSMA6, indicating that miR-4490 can be tested as a biomarker for nephropathy in diabetic patients.


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