scholarly journals High glucose-induced ubiquitylation of G6PD leads to the injury of podocyte

2018 ◽  
Author(s):  
Meng Wang ◽  
Ji Hu ◽  
Linling Yan ◽  
Yeping Yang ◽  
Min He ◽  
...  

AbstractOxidative stress contributes substantially to podocyte injury in diabetic kidney disease. The mechanism of hyperglycemia-induced oxidative stress in podocytes is not fully understood. Glucose-6-phosphate dehydrogenase is critical in maintaining NADPH, an important cofactor for antioxidant system. Here, we hypothesized that high glucose induces ubiquitylation and degradation of G6PD, which injures podocytes by reactive oxygen species (ROS) accumulation. We found that both G6PD protein expression and G6PD activity was decreased in kidneys of both diabetic patients and diabetic rodents. Overexpressing G6PD reversed redox imbalance and podocyte apoptosis induced by high glucose and palmitate. Inhibition of G6PD induced podocyte apoptosis. In G6PD deficient mice, podocyte apoptosis was also largely increased. High glucose had no effect on G6PD mRNA level but it caused decreased G6PD protein expression, which was mediated by the ubiquitin proteasome pathway. Furthermore, von Hippel−Lindau (VHL), an E3 ubiquitin ligase subunit, directly bound to G6PD and degraded G6PD through ubiquitylating G6PD on lysine residues 366/403. Our data suggest that high glucose induces ubiquitylation of G6PD by VHL, which leads to ROS accumulation and podocyte injury.

Author(s):  
Haiyun Sun ◽  
Chong Wang ◽  
Ying Zhou ◽  
Xingbo Cheng

Objective: Diabetic cardiomyopathy (DCM) is an important complication of diabetes. This study was attempted to discover the effects of long noncoding RNA OIP5-AS1 (OIP5-AS1) on the viability and oxidative stress of cardiomyocyte in DCM. Methods: The expression of OIP5-AS1 and microRNA-34a (miR-34a) in DCM was detected by qRT-PCR. In vitro, DCM was simulated by high glucose (HG, 30 mM) treatment in H9c2 cells. The viability of HG (30 mM)-treated H9c2 cells was examined by MTT assay. The reactive oxygen species (ROS), superoxide dismutase (SOD) and malondialdehyde (MDA) levels were used to evaluate the oxidative stress of HG (30 mM)-treated H9c2 cells. Dual-luciferase reporter assay was used to confirm the interactions among OIP5-AS1, miR-34a and SIRT1. Western blot was applied to analyze the protein expression of SIRT1. Results: The expression of OIP5-AS1 was down-regulated in DCM, but miR-34a was up-regulated. The functional experiment stated that OIP5-AS1 overexpression increased the viability and SOD level, while decreased the ROS and MDA levels in HG (30 mM)-treated H9c2 cells. The mechanical experiment confirmed that OIP5-AS1 and SIRT1 were both targeted by miR-34a with the complementary binding sites at 3′UTR. MiR-34a overexpression inhibited the protein expression of SIRT1. In the feedback experiments, miR-34a overexpression or SIRT1 inhibition weakened the promoting effect on viability, and mitigated the reduction effect on oxidative stress caused by OIP5-AS1 overexpression in HG (30 mM)-treated H9c2 cells. Conclusions: OIP5-AS1 overexpression enhanced viability and attenuated oxidative stress of cardiomyocyte via regulating miR-34a/SIRT1 axis in DCM, providing a new therapeutic target for DCM.


2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Dan Shan ◽  
Samuel Kofi Arhin ◽  
Junzhao Zhao ◽  
Haitao Xi ◽  
Fan Zhang ◽  
...  

Background. Deficient spermatozoon motility is one of the main causes of male infertility. However, there are still no accurate and effective treatments in a clinical setting for male asthenospermia. Exploring the genes and mechanism of asthenospermia has become one of the hot topics in reproductive medicine. Our aim is to study the effect of SLRIP on human spermatozoon motility and oxidative stress. Methods. Sperm samples were collected including a normospermia group (60 cases) and an asthenospermia group (50 cases). SLIRP protein expression in spermatozoa was examined by western blotting, and relative mRNA expression of SLIRP in spermatozoa was quantified by reverse transcription polymerase chain reaction. Levels of reactive oxygen species (ROS), adenosine triphosphate (ATP) content, and the activity of manganese superoxide dismutase (MnSOD) in spermatozoa were also measured. Results. The mRNA level and protein expression of SLIRP in the asthenospermia group were significantly reduced compared with those in the normospermia group. The ROS active oxygen level in the asthenospermia group significantly increased; however, the ATP content decreased significantly as well as the activity of MnSOD. Conclusion. SLIRP regulates human male fertility, and SLIRP and sperm progressive motility are positively correlated. The expression of SLIRP is declined, oxidative damage is increased, and energy metabolism is decreased in spermatozoa of asthenospermia patients compared to normospermia participants.


2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Vladislav Slobodsky ◽  
Adi Litmanovich ◽  
Kamal Hassan ◽  
Khaled Khazim

Abstract Background and Aims Pro-inflammatory cytokines are one of several factors which contribute to the progression of diabetic kidney disease (DKD), a condition characterized by chronic kidney inflammation which results in the tubulointerstitial fibrosis which contributes to the progression of DKD. Interleukin 1 (IL-1) two main agonists IL-1α and IL-1β activate a pro-inflammatory cascade in response to different inflammatory stimuli, including hyperglycemia. It was previously shown that a deficiency of NLRP3 which is required for the conversion of IL-1 to its active state, protects mice from the development and progression of DKD. We hypothesize that the chronic hyperglycemia in diabetic patients triggers the activation and release of IL1α and/or IL-1β from renal tubular cells and that this activation leads to the tissue fibrosis. We aim to assess Il-1 and fibronectin expression in an immortalized proximal tubule epithelial cell line from normal adult human kidney (HK-2). In addition, we evaluate the influence of Anakinra™, a pharmaceutical inhibitor of the Il-1 receptor, currently indicated mainly for rheumatoid diseases, on the levels of fibronectin expression in this model. Methods HK-2 cells were cultured and treated with either physiological glucose concentration (5.5mM), high glucose (30mM) or 30mM mannitol as osmotic control for 24 hours to evaluate their effects on Il-1 expression and fibronectin expression. mRNA levels of IL-1α, IL-1β and fibronectin were assessed in q-PCR, and protein expression levels were quantified by western blotting. Immunofluorescence was used to visually demonstrate the presence of IL-1α and IL-1β upon stimulation. Finally, Anakinra™ was added to the tissue cultures in a range of physiologic prescribed concentrations and its effect on cell fibrosis was assessed by the measurement of fibronectin expression 24 hours later by western blotting. Results mRNA and protein expression of IL-1α but mostly IL-1β was elevated in HK-2 cells under hyperglycemic conditions but not in physiological glucose environment or under high osmotic conditions. Fibronectin levels were elevated in the high glucose treated cells compared with control. Finally, Anakinra™ was found to attenuate fibronectin expression under high glucose conditions, compared with the untreated cells. Conclusion Proinflammatory IL-1α and IL-1β cytokines are expressed by HK-2 cells upon stimulation with glucose and result in the fibrosis on the cells measured by the production of fibronectin. The addition of Anakinra™, an IL-1 receptor blocker, to the cell culture attenuate the expression of fibronectin by the tubular cells. Our research is the first to describe a causation between hyperglycemia, IL-1 elevated levels and fibrosis in HK-2 cells, as demonstrated by the beneficial effect of Anakinra™ on lowering fibronectin expression.


2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Xiaoyu Gu ◽  
Tingting Fang ◽  
Pinfang Kang ◽  
Junfeng Hu ◽  
Ying Yu ◽  
...  

Our study aimed firstly to observe whether ALDH2 was expressed in neonate rat cardiac fibroblasts, then to investigate the effect of activation of ALDH2 on oxidative stress, apoptosis, and fibrosis when cardiac fibroblasts were subjected to high glucose intervention. Cultured cardiac fibroblasts were randomly divided into normal (NG), NG + Alda-1, high glucose (HG), HG + Alda-1, HG + Alda-1 + daidzin, HG + daidzin, and hypertonic groups. Double-label immunofluorescence staining, RT-PCR, and Western blot revealed ALDH2 was expressed in cardiac fibroblasts. Compared with NG, ALDH2 activity and protein expression were reduced, and cardiac fibroblast proliferation, ROS releasing, 4-HNE protein expression, collagen type I and III at mRNA levels, and the apoptosis rate were increased in HG group. While in HG + Alda-1 group, with the increases of ALDH2 activity and protein expression, the cardiac fibroblast proliferation and ROS releasing were decreased, and 4-HNE protein expression, collagen type I and III at mRNA levels, and apoptosis rate were reduced compared with HG group. When treated with daidzin in HG + Alda-1 group, the protective effects were inhibited. Our findings suggested that ALDH2 is expressed in neonate rat cardiac fibroblasts; activation of ALDH2 decreases the HG-induced apoptosis and fibrosis through inhibition of oxidative stress.


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Zhong-Jie Liu ◽  
Wei Zhao ◽  
Hong-Yi Lei ◽  
Hua-Li Xu ◽  
Lu-Ying Lai ◽  
...  

Bupivacaine, a typical local anesthetic, induces neurotoxicity via reactive oxygen species regulation of apoptosis. High glucose could enhance bupivacaine-induced neurotoxicity through regulating oxidative stress, but the mechanism of it is not clear. Mitochondrial calcium uniporter (MCU), a key channel for regulating the mitochondrial Ca2+ (mCa2+) influx, is closely related to oxidative stress via disruption of mCa2+ homeostasis. Whether MCU is involved in high glucose-sensitized bupivacaine-induced neurotoxicity remains unknown. In this study, human neuroblastoma (SH-SY5Y) cells were cultured with high glucose and/or bupivacaine, and the data showed that high glucose enhanced bupivacaine-induced MCU expression elevation, mCa2+ accumulation, and oxidative damage. Next, Ru360, an inhibitor of MCU, was employed to pretreated SH-SY5Y cells, and the results showed that it could decrease high glucose and bupivacaine-induced mCa2+ accumulation, oxidative stress, and apoptosis. Further, with the knockdown of MCU with a specific small interfering RNA (siRNA) in SH-SY5Y cells, we found that it also could inhibit high glucose and bupivacaine-induced mCa2+ accumulation, oxidative stress, and apoptosis. We propose that downregulation expression or activity inhibition of the MCU channel might be useful for restoring the mitochondrial function and combating high glucose and bupivacaine-induced neurotoxicity. In conclusion, our study demonstrated the crucial role of MCU in high glucose-mediated enhancement of bupivacaine-induced neurotoxicity, suggesting the possible use of this channel as a target for curing bupivacaine-induced neurotoxicity in diabetic patients.


2009 ◽  
Vol 24 (5) ◽  
pp. 1497-1505 ◽  
Author(s):  
Zhaoyun Zhang ◽  
Chong Wee Liew ◽  
Diane E. Handy ◽  
Yingyi Zhang ◽  
Jane A. Leopold ◽  
...  

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Shintaro Mukohara ◽  
Yutaka Mifune ◽  
Atsuyuki Inui ◽  
Hanako Nishimoto ◽  
Takashi Kurosawa ◽  
...  

Abstract Background Dehydroepiandrosterone (DHEA), an adrenal steroid, has a protective role against diabetes. This study aimed to investigate the in vitro and in vivo protective effects of DHEA against high glucose-induced oxidative stress in tenocytes and tendons. Methods Tenocytes from normal Sprague-Dawley rats were cultured in low-glucose (LG) or high-glucose (HG) medium with or without DHEA. The experimental groups were: control group (LG without DHEA), LG with DHEA, HG without DHEA, and HG with DHEA. Reactive oxygen species (ROS) production, apoptosis, and messenger RNA (mRNA) expression of NADPH oxidase (NOX) 1 and 4, and interleukin-6 (IL-6) were determined. Further, diabetic rats were divided into a control group and a DHEA-injected group (DHEA group). NOX1 and NOX4 protein expression and mRNA expression of NOX1, NOX4, IL-6, matrix metalloproteinase (MMP)-2, tissue inhibitors of matrix metalloproteinase (TIMP)-2, and type I and III collagens in the Achilles tendon were determined. Results In rat tenocytes, DHEA decreased the expression of NOX1 and IL-6, ROS accumulation, and apoptotic cells. In the diabetic rat Achilles tendon, NOX1 protein expression and mRNA expression of NOX1, IL-6, MMP-2, TIMP-2, and type III collagen were significantly lower while type I collagen expression was significantly higher in the DHEA group than in the control group. Conclusions DHEA showed antioxidant and anti-inflammatory effects both in vitro and in vivo. Moreover, DHEA improved tendon matrix synthesis and turnover, which are affected by hyperglycemic conditions. DHEA is a potential preventive drug for diabetic tendinopathy.


2021 ◽  
Vol 22 (3) ◽  
pp. 1427
Author(s):  
Hye In Kim ◽  
Seok Kyo Seo ◽  
Seung Joo Chon ◽  
Ga Hee Kim ◽  
Inha Lee ◽  
...  

Histone deacetylase inhibitors (HDACi) induce apoptosis preferentially in cancer cells by caspase pathway activation and reactive oxygen species (ROS) accumulation. Suberoylanilide hydroxamic acid (SAHA), a HDACi, increases apoptosis via altering intracellular oxidative stress through thioredoxin (TRX) and TRX binding protein-2 (TBP-2). Because ROS accumulation, as well as the redox status determined by TBP-2 and TRX, are suggested as possible mechanisms for endometriosis, we queried whether SAHA induces apoptosis of human endometrial cells via the TRX–TBP-2 system in endometriosis. Eutopic endometrium from participants without endometriosis, and ectopic endometrium from patients with endometriosis, was obtained surgically. Human endometrial stromal cells (HESCs) and Ishikawa cells were treated with SAHA and cell proliferation was assessed using the CCK-8 assay. Real-time PCR and Western blotting were used to quantify TRX and TBP-2 mRNA and protein expression. After inducing oxidative stress, SAHA was applied. Short-interfering TRX (SiTRX) transfection was performed to see the changes after TRX inhibition. The mRNA and protein expression of TBP-2 was increased with SAHA concentrations in HESCs significantly. The mRNA TBP-2 expression was decreased after oxidative stress, upregulated by adding 2.5 μM of SAHA. The TRX/TBP-2 ratio decreased, apoptosis increased significantly, and SiTRX transfection decreased with SAHA. In conclusion, SAHA induces apoptosis by modulating the TRX/TBP-2 system, suggesting its potential as a therapeutic agent for endometriosis.


2019 ◽  
Vol 10 (1) ◽  
pp. 216-226 ◽  
Author(s):  
Ghada Alomari ◽  
Bahaa Al-Trad ◽  
Salehhuddin Hamdan ◽  
Alaa Aljabali ◽  
Mazhar Al-Zoubi ◽  
...  

Abstract Several recent studies have reported that gold nanoparticles (AuNPs) attenuate hyperglycemia in diabetic animal models without any observed side effects. The present study was intended to provide insight into the effects of 50-nm AuNPs on diabetic kidney disease. Adult male rats were divided into three groups (n = 7/group): control (non-diabetic, ND), diabetic (D), and diabetic treated intraperitoneally with 50-nm AuNPs (AuNPs + D; 2.5 mg/kg/day) for 7 weeks. Diabetes was induced by a single-dose injection of 55 mg/kg streptozotocin. The result showed that AuNP treatment prevented diabetes-associated increases in the blood glucose level. Reduction in 24-h urinary albumin excretion rate, glomerular basement membrane thickness, foot process width, and renal oxidative stress markers was also demonstrated in the AuNP-treated group. In addition, the results showed downregulation effect of AuNPs in renal mRNA or protein expression of transforming growth factor β1 (TGF-β1), fibronectin, collagen IV, tumor necrosis factor-α (TNF-α), and vascular endothelial growth factor-A (VEGF-A). Moreover, the protein expression of nephrin and podocin, podocyte markers, in glomeruli was increased in the AuNPs + D group compared with the D group. These results provide evidence that 50-nm AuNPs can ameliorate renal damage in experimental models of diabetic nephropathy through improving the renal function and downregulating extracellular matrix protein accumulation, along with inhibiting renal oxidative stress and amelioration of podocyte injury.


2021 ◽  
Author(s):  
Shintaro Mukohara ◽  
Yutaka Mifune ◽  
Atsuyuki Inui ◽  
Hanako Nishimoto ◽  
Takashi Kurosawa ◽  
...  

Abstract BackgroundDehydroepiandrosterone (DHEA), an adrenal steroid, has a protective role against diabetes. The aim of this study was to investigate the in vitro and in vivo protective effects of DHEA against high glucose-induced oxidative stress in tenocytes and tendons. Methods In an in vitro study, tenocytes from normal Sprague-Dawley rats were cultured in low-glucose (LG) or high-glucose (HG) medium with or without DHEA. The experimental groups were: control group (LG without DHEA), LG with DHEA, HG without DHEA, and HG with DHEA. Reactive oxygen species (ROS) production, apoptosis, and messenger RNA (mRNA) expression of NADPH oxidase (NOX) 1 and 4, and interleukin-6 (IL-6) were determined. In the in vivo study, diabetic rats were divided into a control group and a DHEA-injected group (DHEA group). NOX1 and NOX4 protein expression and mRNA expression of NOX1, NOX4, IL-6, matrix metalloproteinase (MMP)-2, tissue inhibitors of matrix metalloproteinase (TIMP)-2, and type I and III collagens in the Achilles tendon were determined. Results In rat tenocytes, DHEA decreased the expression of NOX1 and IL-6, ROS accumulation, and apoptotic cells. In the diabetic rat Achilles tendon, NOX1 protein expression and mRNA expression of NOX1, IL-6, MMP-2, TIMP-2, and type III collagen were significantly lower, while type I collagen expression was significantly lower in the DHEA group.Conclusions DHEA showed antioxidant and anti-inflammatory effects both in vitro and in vivo. Moreover, DHEA improved tendon matrix synthesis and turnover which are affected by hyperglycemic conditions. DHEA could be a preventive drug for the diabetic tendinopathy.


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