High Glucose Levels Down-Regulate Glucose Transporter Expression That Correlates With Increased Oxidative Stress in Placental Trophoblast Cells IN Vitro

2004 ◽  
Vol 11 (2) ◽  
pp. 75-81 ◽  
Author(s):  
Hui Li ◽  
Yang Gu ◽  
Yanping Zhang ◽  
Michael J. Lucas ◽  
Yuping Wang
Author(s):  
Novi Khila Firani ◽  
Bambang Prijadi

Retinol is one of the active forms of vitamin A. In the previous study, it was known that retinol level in serum of DM patient waslower than in healthy people, which correlated with an increase of the glucose levels in these patients. The importance of retinol in insulinsignaling mechanisms that play a role in the pathogenesis of DM is still unknown. One of the components that play a role in insulinsignaling on adipocytes is phosphatidylinositol-3 kinase (PI3K), which encourages the translocation of glucose transporter-4 (GLUT4) tothe cell surface. The aim of this study was to know the importance of retinol therapy in the levels of PI3K enzyme on visceral adipocyteculture with high glucose exposure (25 mM) as a model of DM in vitro by determination method. Retinol therapy was given at a doseof 0.1 μM, 1 μM , and 10 μM. Measurement of PI3K level was done by ELISA method. The mean (SD) levels of PI3K enzyme were 1.91(0.27), 0.94 (0.15), 1.98 (0.22), 1.69 (0.81), 2.04 (0.16) ng/mL respectively, for adipocyte cultures exposed to 5mM glucose (as aphysiological condition), 25mM glucose, and 25mM glucose concentration with doses of retinol therapy 0.1 μM, 1 μM and10 μM. Theresults of this study indicated that high glucose exposure (25 mM) decreased the level of PI3K compared with adipocyte’s culture on5 mM glucose exposure. Retinol therapy with a dose of 0.1μM, 1μM and10 μM on adipocyte culture exposed with high glucose couldincrease the levels of PI3K.


2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Meng-Fu Cheng ◽  
Li-Jen Chen ◽  
Juei-Tang Cheng

Theklothogene is expressed in a limited number of tissues, most notably in distal convoluted tubules in the kidney and choroid plexus in the brain. A previous study suggested that Klotho increases resistance to oxidative stress. However, changes of Klotho expression in high glucose-induced oxidative stress remain unclear. In the present study, we used streptozotocin-induced diabetic rats (STZ rats) to examine the effects of insulin, phloridzin or antioxidant, tiron on diabetic nephropathy. Both insulin and phloridzin reversed the lower Klotho expression levels in kidneys of STZ rats by the correction of hyperglycemia. Also, renal functions were improved by these treatments. In addition to the improvement of renal functions, the decrease of Klotho expression in kidney of STZ rats was also reversed by tiron without changing blood glucose levels. The reduction of oxidative stress induced by high glucose can be considered for this action of tiron. This view was further confirmed in vitro using high glucose-exposed Madin-Darby canine kidney (MDCK) epithelial cells. Thus, we suggest that decrease of oxidative stress is not only responsible for the improvement of renal function but also for the recovery of Klotho expression in kidney of STZ rats.


2011 ◽  
Vol 13 (1) ◽  
pp. 56-66 ◽  
Author(s):  
Bruno S Pessôa ◽  
Elisa BMI Peixoto ◽  
Alexandros Papadimitriou ◽  
Jacqueline M Lopes de Faria ◽  
José B Lopes de Faria

Spironolactone (SPR), a mineralocorticoid receptor blocker, diminishes hyperglycemia-induced reduction in glucose-6-phosphate dehydrogenase (G6PD) activity, improving oxidative stress damage. This study investigated whether SPR ameliorates nephropathy by increasing G6PD activity and reducing oxidative stress in spontaneously hypertensive diabetic rats (SHRs). The streptozotocin-induced diabetic rats received or not SPR 50 mg/kg per day, for eight weeks. A human mesangial cell line was cultured in normal or high glucose conditions, with or without SPR, for 24 h. Plasma glucose levels and systolic blood pressure were unaltered by diabetes or by SPR treatment. Albuminuria, fibronectin expression, 8-OHdG urinary levels, lipid peroxidation and p47phox expression were higher in the diabetic rats compared with the control and were reduced by SPR. The antioxidant GSH/GSSG ratio was reduced in the diabetic rats and the treatment reestablished it. Diabetes-induced SGK1 up-regulation was inhibited by SPR. Reactive oxygen species (ROS) and superoxide production induced by NADPH oxidase were increased by hyperglycemia and high glucose, in vivo and in vitro, respectively, and were reduced with SPR. Hyperglycemia and high glucose decreased G6PD activity, which was restored with SPR. These results suggest that SPR ameliorates nephropathy in diabetic SHRs by restoring G6PD activity and diminishes oxidative stress without affecting glycaemia and blood pressure.


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.


2001 ◽  
Vol 60 (3) ◽  
pp. 370-376 ◽  
Author(s):  
Robert Augustin ◽  
Paola Pocar ◽  
Anne Navarrete-Santos ◽  
Christine Wrenzycki ◽  
Fulvio Gandolfi ◽  
...  

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Kim A Connelly ◽  
Darren J Kelly ◽  
Michael Zhang ◽  
Kerri Thai ◽  
Andrew Advani ◽  
...  

Background: Alterations in the thioredoxin (TRX) antioxidant system have been implicated in the pathogenesis of cardiac injury, particularly in the diabetic setting. While constitutively present, TRX activity is reduced by the presence of its endogenous inhibitor, thioredoxin interacting protein (TxnIP). We hypothesized that by increasing TxnIP, diabetes may reduce TRX activity and contribute to oxidative stress. Methods: Cell culture studies were performed using the H9C2 rat cardiomyoblast cell line and neonatal cardiomyocytes isolated from 1 day old Sprague Dawley rat neonates. In-vivo studies were performed using a hemodynamically-validated rodent model of diabetic diastolic heart failure, the diabetic (mRen-2)27 transgenic rat (Ren-2). Urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG) was used as a measure of oxidative stress. Results: In- vitro, high glucose (25mmol/l) resulted in increased TxnIP mRNA expression in both neonatal cardiomyocytes as well as H92C cells (2.21 ± 0.6 v 1.00 ± 0.19, p<0.05 compared to normoglycaemic conditions) with a 45% reduction in TRX activity (0.11 ± 0.01 v 0.061± 0.003, p<0.01). In-vivo, diabetes led to a 250% rise in TxnIP mRNA expression compared to control (2.54 ± 0.5 v 1.00 ± 0.11, p<0.001) that was accompanied by a three fold rise in urinary 8-OHdG (680 ± 280 v 1395 ± 391 ng/ml, p<0.001). Conclusion: In both the in vitro and in vivo settings, high glucose leads to TxnIP over-expression associated with reduced TRX activity thereby increasing oxidative stress and implicating this system in the pathogenesis of the cardiac dysfunction that characterizes the diabetic state. Pharmacological manipulation of the TRX-TxnIP system may represent a novel target to reduce diabetic complications.


2020 ◽  
Vol 8 (1) ◽  
pp. e001426
Author(s):  
Wei Wu ◽  
Jinna Yuan ◽  
Yu Shen ◽  
Yunxian Yu ◽  
Xuefeng Chen ◽  
...  

IntroductionThis study was performed to investigate the role of iron overload in the early stage of hyperglycemia-induced vascular functional impairment.Research design and methodsA total of 196 obese children were enrolled, and data regarding ferritin levels, blood glucose levels, intima-media thickness of carotid arteries, liver function and fibrosis index, hemoglobin, blood pressure, blood lipids, and inflammation indicators were collected. Ferritin levels were compared with a control group, which consisted of 148 healthy non-obese children who were age-matched and gender-matched. Endothelial cells were cultured in high glucose medium and supplemented with ferric citrate with or without iron remover (deferoxamine), a reducing agent (N-acetyl-cysteine), or a nuclear factor-κB (NF-κB) inhibitor (BAY 11-7082). Apoptosis, oxidative stress, nitric oxide levels, and endothelin content were evaluated. DNA microarray analysis was performed to analyze the expression of genes in the NF-κB signaling pathway.ResultsObese children have significantly higher ferritin levels compared with the control group. Ferritin level was positively correlated with hemoglobin and was related to metabolic disorders, including impaired glucose tolerance, higher blood pressure, dyslipidemia, and impaired hepatic function. Endothelial cells treated with ferric citrate showed a significantly higher rate of apoptosis, higher levels of oxidative stress, and impaired vasomotor function under high glucose conditions. The above effects were rescued by treatment with an iron remover, reducing agent, or NF-κB inhibitor. Further, detection of phosphorylated-p65 distribution in cells confirmed activation of the NF-κB pathway. DNA microarrays and subsequent gene oncology enrichment analyses revealed the main processes activated in cells.ConclusionIncreased ferritin levels are related to impaired glucose tolerance and other metabolic disorders in obese children. At the cellular level, iron overload aggravated the endothelial cell dysfunction caused by high glucose.


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Kaifeng Li ◽  
Mengen Zhai ◽  
Liqing Jiang ◽  
Fan Song ◽  
Bin Zhang ◽  
...  

Hyperglycemia-induced oxidative stress and fibrosis play a crucial role in the development of diabetic cardiomyopathy (DCM). Tetrahydrocurcumin (THC), a major bioactive metabolite of natural antioxidant curcumin, is reported to exert even more effective antioxidative and superior antifibrotic properties as well as anti-inflammatory and antidiabetic abilities. This study was designed to investigate the potential protective effects of THC on experimental DCM and its underlying mechanisms, pointing to the role of high glucose-induced oxidative stress and interrelated fibrosis. In STZ-induced diabetic mice, oral administration of THC (120 mg/kg/d) for 12 weeks significantly improved the cardiac function and ameliorated myocardial fibrosis and cardiac hypertrophy, accompanied by reduced reactive oxygen species (ROS) generation. Mechanically, THC administration remarkably increased the expression of the SIRT1 signaling pathway both in vitro and in vivo, further evidenced by decreased downstream molecule Ac-SOD2 and enhanced deacetylated production SOD2, which finally strengthened antioxidative stress capacity proven by repaired activities of SOD and GSH-Px and reduced MDA production. Additionally, THC treatment accomplished its antifibrotic effect by depressing the ROS-induced TGFβ1/Smad3 signaling pathway followed by reduced expression of cardiac fibrotic markers α-SMA, collagen I, and collagen III. Collectively, these finds demonstrated the therapeutic potential of THC treatment to alleviate DCM mainly by attenuating hyperglycemia-induced oxidative stress and fibrosis via activating the SIRT1 pathway.


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Jing-Shang Wang ◽  
Ye Huang ◽  
Shuping Zhang ◽  
Hui-Jun Yin ◽  
Lei Zhang ◽  
...  

Hyperglycemia fluctuation is associated with diabetes mellitus (DM) complications when compared to persistent hyperglycemia. Previous studies have shown that paeoniflorin (PF), through its antiapoptosis, anti-inflammation, and antithrombotic properties, effectively protects against cardiovascular and cerebrovascular disease. However, the mechanism underlying the protection from PF against vascular injuries induced by hyperglycemia fluctuations remains poorly understood. Herein, we investigated the potential protective role of PF on human umbilical vein endothelial cells (HUVECs) subjected to intermittent glucose levels in vitro and in DM rats with fluctuating hyperglycemia in vivo. A remarkable increased apoptosis associated with elevated inflammation, increased oxidative stress, and high protein level of PKCβ1 was induced in HUVECs by intermittently changing glucose for 8 days, and PF recovered those detrimental changes. LY333531, a potent PKCβ1 inhibitor, and metformin manifested similar effects. Additionally, in DM rats with fluctuating hyperglycemia, PF protected against vascular damage as what has been observed in vitro. Taken together, PF attenuates the vascular injury induced by fluctuant hyperglycemia through oxidative stress inhibition, inflammatory reaction reduction, and PKCβ1 protein level repression, suggesting its perspective clinical usage.


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