scholarly journals PKCδPromotes High Glucose Induced Renal Tubular Oxidative Damage via Regulating Activation and Translocation of p66Shc

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Panai Song ◽  
Shikun Yang ◽  
Li Xiao ◽  
Xiaoxuan Xu ◽  
Chengyuan Tang ◽  
...  
Keyword(s):  
Oxidative Damage ◽  
High Glucose ◽  
Cell Injury ◽  
Critical Role ◽  
Dependent Manner ◽  
Ros Production ◽  
Tubular Injury ◽  
Renal Tubular ◽  
Stage Renal Disease

Diabetic kidney disease (DKD) is a leading cause of end-stage renal disease (ESRD). Renal tubular injury by overproduction of ROS in mitochondria plays a critical role in the pathogenesis of DKD. Evidences have shown that p66Shc was involved in renal tubular injury via mitochondrial-dependent ROS production pathway, but little is known about the upstream signaling of p66Shc that leads to tubular oxidative damage under high glucose conditions. In this study, an increased PKCδand p66Shc activation and ROS production in renal tissues of patients with diabetic nephropathy were seen and further analysis revealed a positive correlation between the tubulointerstitial damage and p-PKCδ, p-p66Shc, and ROS production. In vitro, we investigated the phosphorylation and activation of p66Shc and PKCδduring treatment of HK-2 cells with high glucose (HG). Results showed that the activation of p66Shc and PKCδwas increased in a dose- and time-dependent manner, and this effect was suppressed by Rottlerin, a pharmacologic inhibitor of PKCδ. Moreover, PKCδsiRNA partially blocked HG-induced p66Shc phosphorylation, translocation, and ROS production in HK-2 cells. Taken together, these data suggest that activation of PKCδpromotes tubular cell injury through regulating p66Shc phosphorylation and mitochondrial translocation in HG ambient.

scholarly journals Renoprotective Effects of Aldose Reductase Inhibitor Epalrestat against High Glucose-Induced Cellular Injury

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Heba El Gamal ◽  
Ali Hussein Eid ◽  
Shankar Munusamy
Keyword(s):  
Cell Cycle ◽  
Cell Viability ◽  
Aldose Reductase ◽  
High Glucose ◽  
Mitochondrial Membrane ◽  
Cell Injury ◽  
Renal Tubular ◽  
Stage Renal Disease ◽  
End Stage

Diabetic nephropathy (DN) is the leading cause of end stage renal disease worldwide. Increased glucose flux into the aldose reductase (AR) pathway during diabetes was reported to exert deleterious effects on the kidney. The objective of this study was to investigate the renoprotective effects of AR inhibition in high glucose milieu in vitro. Rat renal tubular (NRK-52E) cells were exposed to high glucose (30 mM) or normal glucose (5 mM) media for 24 to 48 hours with or without the AR inhibitor epalrestat (1 μM) and assessed for changes in Akt and ERK1/2 signaling, AR expression (using western blotting), and alterations in mitochondrial membrane potential (using JC-1 staining), cell viability (using MTT assay), and cell cycle. Exposure of NRK-52E cells to high glucose media caused acute activation of Akt and ERK pathways and depolarization of mitochondrial membrane at 24 hours. Prolonged high glucose exposure (for 48 hours) induced AR expression andG1 cell cycle arrest and decreased cell viability (84% compared to control) in NRK-52E cells. Coincubation of cells with epalrestat prevented the signaling changes and renal cell injury induced by high glucose. Thus, AR inhibition represents a potential therapeutic strategy to prevent DN.

scholarly journals miR-30e targets GLIPR-2 to modulate diabetic nephropathy: in vitro and in vivo experiments

2017 ◽  
Vol 59 (2) ◽  
pp. 181-190 ◽  
Author(s):  
Dong Zhao ◽  
Jinhua Jia ◽  
Hong Shao
Keyword(s):  
High Glucose ◽  
Luciferase Reporter ◽  
Dependent Manner ◽  
Luciferase Reporter Gene ◽  
Related Factors ◽  
Qrt Pcr ◽  
In Vivo Experiments ◽  
Renal Tubular

The objectives of this study are to investigate the effect of miR-30e targeting GLIPR-2 on the pathological mechanism of DN. The renal tissues of db/db and db/m mice at different age of weeks were stained with PAS. qRT-PCR was applied to detect the expression of miR-30e and GLIPR-2, not only in the renal tissues of mice but also in the renal tubular epithelial cells (RTECs). By luciferase reporter gene assays, we found the 3′-UTR of the GLIPR-2 mRNA as a direct target of miR-30e. The RTECs cultured in high glucose were divided into blank control, NC, miR-30e mimics, miR-30e inhibitors, miR-30e inhibitor + si-GLIPR-2 and si-GLIPR-2 groups. MTT and flow cytometry were utilized to measure the proliferation and apoptosis of RTECs, while qRT-PCR and Western blot to detect the expression of GLIPR-2- and EMT-related factors. The following results were obtained: In the renal tissues of over 8-week-old db/db mice and the RTECs cultured for 6 h in high glucose, miR-30e was downexpressed while GLIPR-2 was upregulated in a time-dependent manner. Besides, overexpression of miR-30e and si-GLIPR-2 can not only greatly improve the proliferation of RTECs cultured in high glucose, but also downregulate the apoptosis rate of RTECs and the expressions of GLIPR-2, vimentin, α-SMA, Col-I and FN and upregulate E-cadherin. Moreover, si-GLIPR-2 can reverse the proliferation reduction, GLIPR-2 and EMT occurrence caused by the downexpression of miR-30e in RTECs. In conclusion, miR-30e is downregulated in DN, and the overexpression of miR-30e can inhibit GLIPR-2, promote the proliferation of RTECs and inhibit EMT, ultimately avoid leading to renal fibrosis in DN.

Clusterin protects renal tubular epithelial cells from gentamicin-mediated cytotoxicity

2002 ◽  
Vol 282 (4) ◽  
pp. F703-F709 ◽  
Author(s):  
Richard A. Girton ◽  
David P. Sundin ◽  
Mark E. Rosenberg
Keyword(s):  
Proximal Tubule ◽  
Cell Injury ◽  
Renal Tubular Cell ◽  
Dependent Manner ◽  
Proximal Tubule Cells ◽  
Lactate Dehydrogenase Release ◽  
Tubule Cells ◽  
Renal Proximal Tubule Cells ◽  
Renal Tubular

Clusterin is a heterodimeric secreted glycoprotein that is upregulated after acute renal injury. In aminoglycoside nephrotoxicity, clusterin is induced in the tubular epithelium and increased levels are found in the urine. In this study, we developed an in vitro model of gentamicin-induced cytotoxicity in renal proximal tubule cells and tested whether clusterin protected these cells from injury. LLC-PK1 cells were incubated with varying concentrations of gentamicin in serum-free media, and cytotoxicity was quantified by lactate dehydrogenase release and confirmed by vital dye exclusion. A dose-dependent increase in cytotoxicity occurred with gentamicin concentrations up to 27 mg/ml. Clusterin decreased cytotoxicity in a dose- and time-dependent manner at 6, 12, and 24 h, whereas albumin, used as a control protein, had no effect. In contrast to the aminoglycoside model, when cells were injured by depletion of ATP, clusterin had only a minimally protective effect. LLC-PK1 cells did not express megalin, a receptor that can mediate the uptake of both clusterin and aminoglycosides into proximal tubule cells. Uptake of gentamicin into LLC-PK1cells was observed despite the absence of megalin. In conclusion, clusterin specifically protects against gentamicin-induced renal tubular cell injury by a megalin-independent mechanism.

scholarly journals Atrasentan increased the expression of klotho by mediating miR-199b-5p and prevented renal tubular injury in diabetic nephropathy

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Wen-Ling Kang ◽  
Gao-Si Xu
Keyword(s):  
Diabetic Nephropathy ◽  
High Glucose ◽  
Tubular Injury ◽  
Mice Model ◽  
Renal Tubular Cells ◽  
Proximal Tubular ◽  
Renal Proximal Tubular ◽  
Renal Tubular

Abstract Atrasentan is a promising therapy for treating diabetic nephropathy (DN). Here we evaluated whether atrasentan down-regulated the miR-199b-5p expression, thereby increasing klotho and preventing renal tubular injury in DN. One-hundred patients with type 2 diabetes mellitus (T2DM) and 40 healthy subjects were included. A DN mice model was established by an injection of streptozotocin (STZ). Human renal proximal tubular epithelial HK-2 cells were exposed to high glucose (20 mmol/L). Treated the mice and HK-2 cells with atrasentan and we then investigated whether and how miR-199b-5p and Klotho were involved in preventing renal tubular injury in DN. In patients, the serum miR-199b-5p level increased and the klotho concentration decreased in accordance with elevated albuminuria. Atrasentan down-regulated miR-199b-5p and up-regulated klotho of the DN mice and HK-2 cells exposed to high glucose. High glucose promoted the binding of histone H3 to the miR-199b-5p promoter and atrasentan canceled this effect. MiR-199b-5p targeted the 3′ UTR of klotho. Overexpression of miR-199b-5p canceled the effects of atrasentan on klotho expression and apoptosis of renal tubular cells in both in vivo and in vitro. The increased serum klotho, mediated by miR-199b-5p, is a possible mechanism by which atrasentan prevents renal tubular injury in DN.

scholarly journals CD36 promotes NLRP3 inflammasome activation via the mtROS pathway in renal tubular epithelial cells of diabetic kidneys

2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Yanjuan Hou ◽  
Qian Wang ◽  
Baosheng Han ◽  
Yiliang Chen ◽  
Xi Qiao ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
High Glucose ◽  
Inflammasome Activation ◽  
Ros Production ◽  
Tubular Epithelial Cells ◽  
Renal Tubular Epithelial Cells ◽  
Nlrp3 Inflammasome Activation ◽  
Ampk Activity ◽  
Renal Tubular ◽  
Tubulointerstitial Inflammation

AbstractTubulointerstitial inflammation plays a key role in the pathogenesis of diabetic nephropathy (DN). Interleukin-1β (IL-1β) is the key proinflammatory cytokine associated with tubulointerstitial inflammation. The NLRP3 inflammasome regulates IL-1β activation and secretion. Reactive oxygen species (ROS) represents the main mediator of NLRP3 inflammasome activation. We previously reported that CD36, a class B scavenger receptor, mediates ROS production in DN. Here, we determined whether CD36 is involved in NLRP3 inflammasome activation and explored the underlying mechanisms. We observed that high glucose induced-NLRP3 inflammasome activation mediate IL-1β secretion, caspase-1 activation, and apoptosis in HK-2 cells. In addition, the levels of CD36, NLRP3, and IL-1β expression (protein and mRNA) were all significantly increased under high glucose conditions. CD36 knockdown resulted in decreased NLRP3 activation and IL-1β secretion. CD36 knockdown or the addition of MitoTempo significantly inhibited ROS production in HK-2 cells. CD36 overexpression enhanced NLRP3 activation, which was reduced by MitoTempo. High glucose levels induced a change in the metabolism of HK-2 cells from fatty acid oxidation (FAO) to glycolysis, which promoted mitochondrial ROS (mtROS) production after 72 h. CD36 knockdown increased the level of AMP-activated protein kinase (AMPK) activity and mitochondrial FAO, which was accompanied by the inhibition of NLRP3 and IL-1β. The in vivo experimental results indicate that an inhibition of CD36 could protect diabetic db/db mice from tubulointerstitial inflammation and tubular epithelial cell apoptosis. CD36 mediates mtROS production and NLRP3 inflammasome activation in db/db mice. CD36 inhibition upregulated the level of FAO-related enzymes and AMPK activity in db/db mice. These results suggest that NLRP3 inflammasome activation is mediated by CD36 in renal tubular epithelial cells in DN, which suppresses mitochondrial FAO and stimulates mtROS production.

LRG1 Mitigates Renal Interstitial Fibrosis through Alleviating Capillary Rarefaction and Inhibiting Inflammatory and Pro-Fibrotic Cytokines

2021 ◽  
pp. 1-11
Author(s):  
Ting-Ting Liu ◽  
Ran Luo ◽  
Yi Yang ◽  
Yi-Chun Cheng ◽  
Dan Chang ◽  
...  
Keyword(s):  
Renal Fibrosis ◽  
Interstitial Fibrosis ◽  
Critical Role ◽  
Tube Formation ◽  
Renal Interstitial Fibrosis ◽  
Genetic Ablation ◽  
Capillary Rarefaction ◽  
Peritubular Capillaries ◽  
Renal Tubular

<b><i>Introduction:</i></b> Increasing evidence has demonstrated that loss of peritubular capillaries plays a critical role in renal interstitial fibrosis. Leucine-rich α2-glycoprotein-1 (LRG1) has been observed promoting angiogenesis in the ocular disease mouse model and myocardial infarction model. We aimed to explore the role of LRG1 in renal interstitial fibrosis. <b><i>Methods:</i></b> We analyzed the expression of LRG1 in the plasma and kidney of CKD patients by ELISA and immunohistochemistry. Relationships between the expression of LRG1 in plasma and kidney and renal fibrosis and inflammation were analyzed. Tube formation assay was used to detect the angiogenesis in the human umbilical vein endothelial cell lines (HUVECs). And real-time PCR was used to detect the mRNA expression of LRG1, inflammatory factors, renal tubular injury indicators, pro-fibrotic cytokines, and CD31. We examined the effects of genetic ablation of LRG1 on renal fibrosis induced by unilateral ureteral obstruction (UUO) mice model at day 7. <b><i>Results:</i></b> We demonstrated that the expression of LRG1 in renal tissues and plasma samples was upregulated in CKD patients. And the expression of LRG1 was elevated in human renal tubular epithelial cell line (HK-2) cells in response to the stimulation of TNF-α in vitro, and in kidney after UUO in vivo. The deficiency of the LRG1 gene aggravated renal fibrosis, inflammatory cells infiltration, and capillary rarefaction after UUO. In vitro, LRG1 promoted the tube formation of HUVEC cells. LRG1 inhibits fibronectin secretion induced by TGF-β1 in HK-2 and overexpression of LRG1 in HK-2 cells decreased fibronectin secretion. <b><i>Conclusion:</i></b> LRG1 may prevent renal fibrosis by inhibiting the secretion of inflammatory and pro-fibrotic cytokines and promoting angiogenesis.

scholarly journals High Glucose and Lipopolysaccharide Prime NLRP3 Inflammasome via ROS/TXNIP Pathway in Mesangial Cells

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Hong Feng ◽  
Junling Gu ◽  
Fang Gou ◽  
Wei Huang ◽  
Chenlin Gao ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Nlrp3 Inflammasome ◽  
High Glucose ◽  
Mesangial Cells ◽  
Central Component ◽  
Dependent Manner ◽  
Glomerular Mesangial Cells ◽  
Interacting Protein

While inflammation is considered a central component in the development in diabetic nephropathy, the mechanism remains unclear. The NLRP3 inflammasome acts as both a sensor and a regulator of the inflammatory response. The NLRP3 inflammasome responds to exogenous and endogenous danger signals, resulting in cleavage of procaspase-1 and activation of cytokines IL-1β, IL-18, and IL-33, ultimately triggering an inflammatory cascade reaction. This study observed the expression of NLRP3 inflammasome signaling stimulated by high glucose, lipopolysaccharide, and reactive oxygen species (ROS) inhibitor N-acetyl-L-cysteine in glomerular mesangial cells, aiming to elucidate the mechanism by which the NLRP3 inflammasome signaling pathway may contribute to diabetic nephropathy. We found that the expression of thioredoxin-interacting protein (TXNIP), NLRP3, and IL-1βwas observed by immunohistochemistry in vivo. Simultaneously, the mRNA and protein levels of TXNIP, NLRP3, procaspase-1, and IL-1βwere significantly induced by high glucose concentration and lipopolysaccharide in a dose-dependent and time-dependent manner in vitro. This induction by both high glucose and lipopolysaccharide was significantly inhibited by N-acetyl-L-cysteine. Our results firstly reveal that high glucose and lipopolysaccharide activate ROS/TXNIP/ NLRP3/IL-1βinflammasome signaling in glomerular mesangial cells, suggesting a mechanism by which inflammation may contribute to the development of diabetic nephropathy.

scholarly journals Mn Inhibits GSH Synthesis via Downregulation of Neuronal EAAC1 and Astrocytic xCT to Cause Oxidative Damage in the Striatum of Mice

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Xinxin Yang ◽  
Haibo Yang ◽  
Fengdi Wu ◽  
Zhipeng Qi ◽  
Jiashuo Li ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Oxidative Damage ◽  
Dependent Manner ◽  
Protein Levels ◽  
Key Factor ◽  
Protein Sulfhydryl ◽  
Mrna And Protein Expression ◽  
The Brain

Excessive manganese (Mn) can accumulate in the striatum of the brain following overexposure. Oxidative stress is a well-recognized mechanism in Mn-induced neurotoxicity. It has been proven that glutathione (GSH) depletion is a key factor in oxidative damage during Mn exposure. However, no study has focused on the dysfunction of GSH synthesis-induced oxidative stress in the brain during Mn exposure. The objective of the present study was to explore the mechanism of Mn disruption of GSH synthesis via EAAC1 and xCT in vitro and in vivo. Primary neurons and astrocytes were cultured and treated with different doses of Mn to observe the state of cells and levels of GSH and reactive oxygen species (ROS) and measure mRNA and protein expression of EAAC1 and xCT. Mice were randomly divided into seven groups, which received saline, 12.5, 25, and 50 mg/kg MnCl2, 500 mg/kg AAH (EAAC1 inhibitor) + 50 mg/kg MnCl2, 75 mg/kg SSZ (xCT inhibitor) + 50 mg/kg MnCl2, and 100 mg/kg NAC (GSH rescuer) + 50 mg/kg MnCl2 once daily for two weeks. Then, levels of EAAC1, xCT, ROS, GSH, malondialdehyde (MDA), protein sulfhydryl, carbonyl, 8-hydroxy-2-deoxyguanosine (8-OHdG), and morphological and ultrastructural features in the striatum of mice were measured. Mn reduced protein levels, mRNA expression, and immunofluorescence intensity of EAAC1 and xCT. Mn also decreased the level of GSH, sulfhydryl, and increased ROS, MDA, 8-OHdG, and carbonyl in a dose-dependent manner. Injury-related pathological and ultrastructure changes in the striatum of mice were significantly present. In conclusion, excessive exposure to Mn disrupts GSH synthesis through inhibition of EAAC1 and xCT to trigger oxidative damage in the striatum.

scholarly journals Role of Stat3 Signaling in Control of EMT of Tubular Epithelial Cells During Renal Fibrosis

2017 ◽  
Vol 42 (6) ◽  
pp. 2552-2558 ◽  
Author(s):  
Jingsong Liu ◽  
Ying Zhong ◽  
Guoyong Liu ◽  
Xiaobai Zhang ◽  
Bofei Xiao ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Renal Injury ◽  
Renal Fibrosis ◽  
Critical Role ◽  
Dependent Manner ◽  
Tubular Epithelial Cells ◽  
Mesenchymal Transition ◽  
Stat3 Signaling ◽  
Phosphorylated Stat3

Background/Aims: Transforming growth factor β 1 (TGFβ1) plays a critical role in the epithelial-to-mesenchymal transition (EMT) of renal tubular epithelial cells (TECs) during renal injury, a major cause of acute renal failure, renal fibrosis and obstructive nephropathy. However, the underlying molecular mechanisms remain ill-defined. Here, we addressed this question. Methods: Expression of TGFβ1, Snail, and phosphorylated Stat3 was examined by immunohistochemistry in the kidney after induction of unilateral ureteral obstruction (UUO) in mice. In vitro, primary TECs were purified by flow cytometry, and then challenged with TGFβ1 with/without presence of specific inhibitors for phosphorylation of SMAD3 or Stat3. Protein levels were determined by Western blotting. Results: We detected significant increases in Snail and phosphorylated Stat3, an activated form for Stat3, in the kidney after induction of UUO in mice. In vitro, TGFβ1-challenged primary TECs upregulated Snail, in a SMAD3/Stat3 dependent manner. Conclusion: Our study sheds light on the mechanism underlying the EMT of TECs after renal injury, and suggests Stat3 signaling as a promising innovative therapeutic target for prevention of renal fibrosis.

SIRT1 activator ameliorates the renal tubular injury induced by hyperglycemia in vivo and in vitro via inhibiting apoptosis

2016 ◽  
Vol 83 ◽  
pp. 41-50 ◽  
Author(s):  
Xue-ling Wang ◽  
Li-yan Wu ◽  
Long Zhao ◽  
Li-na Sun ◽  
Hai-ying Liu ◽  
...  
Keyword(s):  
Tubular Injury ◽  
Renal Tubular ◽  
Sirt1 Activator
Sign in / Sign up

Export Citation Format

Share Document