scholarly journals 3H-1,2-Dithiole-3-Thione Protects Lens Epithelial Cells against Fructose-Induced Epithelial-Mesenchymal Transition via Activation of AMPK to Eliminate AKR1B1-Induced Oxidative Stress in Diabetes Mellitus

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1086
Author(s):  
Tsung-Tien Wu ◽  
Ying-Ying Chen ◽  
Chiu-Yi Ho ◽  
Tung-Chen Yeh ◽  
Gwo-Ching Sun ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Epithelial Cells ◽  
Advanced Glycation End Products ◽  
Epithelial Mesenchymal Transition ◽  
Human Lens ◽  
Lens Epithelial Cells ◽  
Advanced Glycation ◽  
Mesenchymal Transition ◽  
Glycation End Products ◽  
End Products

Studies demonstrated that the receptor of advanced glycation end products (RAGE) induced epithelial-mesenchymal transition (EMT) formation in the lens epithelial cells (LECs) of diabetic cataracts. This work investigated how 3H-1,2-dithiole-3-thione (D3T) reduces EMT formation in LECs of the fructose-induced diabetes mellitus (DM). LECs were isolated during cataract surgery from patients without DM or with DM. In a rat model, fructose (10% fructose, eight weeks) with or without D3T (10 mg/kg/day) treatment induced DM, as verified by blood pressure and serum parameter measurements. We observed that the formation of advanced glycation end products (AGEs) was significantly higher in epithelial human lens of DM (+) compared to DM (−) cataracts. Aldose reductase (AKR1B1), AcSOD2, and 3-NT were significantly enhanced in the rat lens epithelial sections of fructose-induced DM, however, the phosphorylation level of AMPKT172 showed a reversed result. Interestingly, administration of D3T reverses the fructose-induced effects in LECs. These results indicated that AMPKT172 may be required for reduced superoxide generation and the pathogenesis of diabetic cataract. Administration of D3T reverses the fructose-induced EMT formation the LECs of fructose-induced DM. These novel findings suggest that the D3T may be a candidate for the pharmacological prevention of cataracts in patients with DM.

scholarly journals Effect of thioltransferase on oxidative stress induced by high glucose and advanced glycation end products in human lens epithelial cells

2021 ◽  
Vol 14 (7) ◽  
pp. 965-972
Author(s):  
Qing Liu ◽  
◽  
Hong Yan ◽  
Keyword(s):  
Oxidative Stress ◽  
Epithelial Cells ◽  
Advanced Glycation End Products ◽  
High Glucose ◽  
Human Lens ◽  
Lens Epithelial Cells ◽  
Advanced Glycation ◽  
Human Lens Epithelial Cells ◽  
Glycation End Products ◽  
End Products

AIM: To study the effect of thioltransferase (TTase) on oxidative stress in human lens epithelial cells (HLECs) induced by high glucose and advanced glycation end products (AGEs). METHODS: HLECs were treated with 35.5 mmol/L glucose or 1.5 mg/mL AGEs modified bovine serum albumin (AGEs-BSA) as the experimental groups, respectively. Cells were collected at the time point of 1, 2, 3, and 4d. The TTase activity were measured accordingly. TTase mRNA levels were detected by quantitative reverse transcription polymerase chain response (qRT-RCR) and its protein level was detected by Western blot. The siRNA was used to knock down the expression of TTase. The activity of catalase (CAT) and superoxide dismutase (SOD), the content of reactive oxygen species (ROS) and the ratio of oxidized glutathione/total glutathione (GSSG/T-GSH) were assessed in different groups, respectively. RESULTS: The level of TTase mRNA gradually increased and reached the top at 2d, then it decreased to the normal level at 4d, and the TTase activity increased from 2 to 3d in both high glucose and AGEs-BSA groups. The TTase expression elevated from 2d in high glucose group, and it began to rise from 3d in AGEs-BSA group. The activity of CAT and SOD showed a decrease and the content of ROS and the ratio of GSSG/T-GSH showed an increase in high glucose and AGEs-BSA group. These biochemical alterations were more prominent in the groups with TTase siRNA. CONCLUSION: High glucose and AGEs can increase ROS content in HLECs; therefore, it induces oxidative stress. This may result in the decreased GSH and increased GSSG content, impaired activity of SOD and CAT. The up-regulated TTase likely provides oxidation damage repair induced by high glucose and AGEs in the early stage.

HMGB1 Enhances the AGE-Induced Expression of CTGF and TGF-β via RAGE-Dependent Signaling in Renal Tubular Epithelial Cells

2015 ◽  
Vol 41 (3) ◽  
pp. 257-266 ◽  
Author(s):  
Meichu Cheng ◽  
Hong Liu ◽  
Dongshan Zhang ◽  
Yinghong Liu ◽  
Chang Wang ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epithelial Cells ◽  
Advanced Glycation End Products ◽  
Tubular Epithelial Cells ◽  
Advanced Glycation ◽  
Induced Expression ◽  
Mesenchymal Transition ◽  
Glycation End Products ◽  
End Products ◽  
Renal Tubular

Background/Aims: Advanced glycation end products (AGEs) induce epithelial mesenchymal transition (EMT) in renal proximal tubular epithelial cells (PTECs) by promoting the two EMT regulators, transforming growth factor beta (TGF-β) and connective tissue growth factor (CTGF). However, the exact signaling mechanism remains largely unclear. Methods: We investigated the promotion to high mobility group box 1 (HMGB1) in renal tubular epithelial HK-2 cells by AGE-BSA with quantitative PCR and western blot assay, and then determined the regulatory role of HMGB1 in the AGE-BSA-induced CTGF and TGF-β. In addition, the dependence of the receptor of advanced glycation end products (RAGE) was also examined in the CTGF and TGF-β promotion by AGEs and HMGB1 in HK-2 cells using the RNAi method. Results: It was demonstrated that AGEs induced translocation and release of HMGB1 from tubular epithelial HK-2 cells, and the released HMGB1 enhanced the promotion to CTGF and TGF-β by AGEs in HK-2 cells. On the other side, the HMGB1 knockdown by siRNA attenuated the AGE-BSA-induced expression of TGF-β. Moreover, the CTGF and TGF-β promotion in HK-2 cells by AGEs and HMGB1 was RAGE-dependent. Conclusion: Our results indicated that AGEs induced HMGB-1 and promoted the CTGF and TGF-β in renal epithelial HK-2 cells RAGE-dependently. And there was a synergism between AGEs and HMGB1 in the RAGE signaling activation. The in vitro data suggested that the AGE-RAGE and HMGB-1-RAGE signaling might play an important role in the promotion of CTGF and TGF-β in the renal fibrosis process of diabetic nephropathy.

scholarly journals AKR1B1-Induced Epithelial–Mesenchymal Transition Mediated by RAGE-Oxidative Stress in Diabetic Cataract Lens

Antioxidants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 273 ◽  
Author(s):  
Tsung-Tien Wu ◽  
Ying-Ying Chen ◽  
Hui-Yu Chang ◽  
Ya-Hsin Kung ◽  
Ching-Jiunn Tseng ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Epithelial Mesenchymal Transition ◽  
Immunofluorescent Staining ◽  
Human Lens ◽  
Lens Epithelial Cells ◽  
Cataract Formation ◽  
Diabetic Cataract ◽  
Mesenchymal Transition ◽  
Pharmacological Prevention ◽  
Glycation End Products

Purpose: Cataracts are a major cause of visual acuity deterioration in diabetes mellitus (DM) in developed and developing countries. Studies have demonstrated that overproduction of AKR1B1 and receptor for advanced glycation end products (RAGE) plays a major role in the pathogenesis of diabetic cataracts, but it is unclear whether the prevalence of diabetic cataracts is related to epithelial–mesenchymal transition (EMT) in lens epithelial cells. This study aimed to analyze the role of EMT in cataract formation of DM patients. Methods: Immunofluorescence and immunohistochemistry assays were used to estimate AKR1B1, RAGE, AMPK, and EMT levels in epithelial human lens of DM or non-DM cataracts. Results: Immunohistochemical staining demonstrated that pathologic phases and N-cadherin expression levels were significantly higher in epithelial human lens of DM (+) compared to DM (−) cataracts. Immunofluorescent staining showed that AKR1B1 and RAGE were significantly higher in epithelial human lens of DM (+) compared to DM (−) cataracts. Interestingly, acetyl superoxide dismutase 2 (AcSOD2) levels were significantly higher in DM patients’ lens epithelial cells (LECs), whereas AMPKT172 phosphorylation was significantly increased in non-DM patients. This indicates that AMPKT172 might be related to superoxide reduction and diabetic cataract formation. Conclusions: Our results suggest that AKR1B1 overexpression can decrease AMPK activation, thereby increasing AcSOD2 and RAGE-induced EMT in epithelial human lens of DM cataracts. These novel findings suggest that AKR inhibitors may be candidates for the pharmacological prevention of cataracts in patients with DM.

scholarly journals Advanced glycation end products induce a prothrombotic phenotype in mice via interaction with platelet CD36

Blood ◽  
2012 ◽  
Vol 119 (25) ◽  
pp. 6136-6144 ◽  
Author(s):  
Weifei Zhu ◽  
Wei Li ◽  
Roy L. Silverstein
Keyword(s):  
Diabetes Mellitus ◽  
Mouse Models ◽  
Advanced Glycation End Products ◽  
Vascular Complications ◽  
Dependent Manner ◽  
Advanced Glycation ◽  
Drug Induced ◽  
Glycation End Products ◽  
End Products

Abstract Diabetes mellitus has been associated with platelet hyperreactivity, which plays a central role in the hyperglycemia-related prothrombotic phenotype. The mechanisms responsible for this phenomenon are not established. In the present study, we investigated the role of CD36, a class-B scavenger receptor, in this process. Using both in vitro and in vivo mouse models, we demonstrated direct and specific interactions of platelet CD36 with advanced glycation end products (AGEs) generated under hyperglycemic conditions. AGEs bound to platelet CD36 in a specific and dose-dependent manner, and binding was inhibited by the high-affinity CD36 ligand NO2LDL. Cd36-null platelets did not bind AGE. Using diet- and drug-induced mouse models of diabetes, we have shown that cd36-null mice had a delayed time to the formation of occlusive thrombi compared with wild-type (WT) in a FeCl3-induced carotid artery injury model. Cd36-null mice had a similar level of hyperglycemia and a similar level of plasma AGEs compared with WT mice under this condition, but WT mice had more AGEs incorporated into thrombi. Mechanistic studies revealed that CD36-dependent JNK2 activation is involved in this prothrombotic pathway. Therefore, the results of the present study couple vascular complications in diabetes mellitus with AGE-CD36–mediated platelet signaling and hyperreactivity.

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