scholarly journals Wnt6 regulates epithelial cell differentiation and is dysregulated in renal fibrosis

2016 ◽  
Vol 311 (1) ◽  
pp. F35-F45 ◽  
Author(s):  
Hayley Beaton ◽  
Darrell Andrews ◽  
Martin Parsons ◽  
Mary Murphy ◽  
Andrew Gaffney ◽  
...  

Diabetic nephropathy is the most common microvascular complication of diabetes mellitus, manifesting as mesangial expansion, glomerular basement membrane thickening, glomerular sclerosis, and progressive tubulointerstitial fibrosis leading to end-stage renal disease. Here we describe the functional characterization of Wnt6, whose expression is progressively lost in diabetic nephropathy and animal models of acute tubular injury and renal fibrosis. We have shown prominent Wnt6 and frizzled 7 (FzD7) expression in the mesonephros of the developing mouse kidney, suggesting a role for Wnt6 in epithelialization. Importantly, TCF/Lef reporter activity is also prominent in the mesonephros. Analysis of Wnt family members in human renal biopsies identified differential expression of Wnt6, correlating with severity of the disease. In animal models of tubular injury and fibrosis, loss of Wnt6 was evident. Wnt6 signals through the canonical pathway in renal epithelial cells as evidenced by increased phosphorylation of GSK3β (Ser9), nuclear accumulation of β-catenin and increased TCF/Lef transcriptional activity. FzD7 was identified as a putative receptor of Wnt6. In vitro Wnt6 expression leads to de novo tubulogenesis in renal epithelial cells grown in three-dimensional culture. Importantly, Wnt6 rescued epithelial cell dedifferentiation in response to transforming growth factor-β (TGF-β); Wnt6 reversed TGF-β-mediated increases in vimentin and loss of epithelial phenotype. Wnt6 inhibited TGF-β-mediated p65-NF-κB nuclear translocation, highlighting cross talk between the two pathways. The critical role of NF-κB in the regulation of vimentin expression was confirmed in both p65−/−and IKKα/β−/−embryonic fibroblasts. We propose that Wnt6 is involved in epithelialization and loss of Wnt6 expression contributes to the pathogenesis of renal fibrosis.

Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Jorge F Giani ◽  
Ellen A Bernstein ◽  
Masahiro Eriguchi ◽  
Romer A Gonzalez-Villalobos ◽  
Kenneth E Bernstein

Research studies demonstrated that interleukin (IL)-1β contributes to the development of diabetic nephropathy and hypertension. However, the origin and regulation of IL-1β synthesis during diabetic kidney injury are still unknown. Here, we hypothesize that renal epithelial cells produce IL-1β in response to a high glucose stress and that angiotensin converting enzyme (ACE) plays a key role in this process. To study this, we isolated proximal tubular (PT) epithelial cells from wild-type (WT) and mice lacking either the ACE N-domain (NKO) or the C-domain (CKO) catalytic activity. These cells were exposed to normal (5 mM) or high (30 mM) glucose for 24 hours. IL-1β produced by PT cells were assessed by ELISA and RT-PCR. High glucose induced WT PT cells to release significant amounts of IL-1β (from 5±1 to 70±6 pg/ml, p<0.001; n=6). When WT PT cells were exposed to a high glucose media in the presence of an ACE inhibitor (lisinopril, 10 mM), IL-1β levels were significantly reduced (from 70±6 to 38±6 pg/ml, p<0.01). In contrast, AT1 receptor blockade by losartan did not change the amount of IL-1β produced by WT PT cells. To determine which ACE domain is associated with IL-1β production, NKO and CKO PT cells were exposed to high glucose. Strikingly, NKO PT cells released lower amounts of IL-1β when exposed to high glucose compared to WT (NKO: 15±7 vs. WT: 79±9 pg/ml, p<0.01, n=4). No differences were observed between WT and CKO PT cells. Since the ACE N-domain degrades the anti-inflammatory tetrapeptide N-acetyl-Ser-Asp-Lys-Pro (AcSDKP), we tested whether the lower IL-1β production in NKO PT cells was due to an accumulation of AcSDKP. For this, we pre-treated NKO PT cells with a prolyl endopeptidase inhibitor (S17092, 50μM) to prevent the production of AcSDKP. Notably, this treatment increased the IL-1β response to high glucose in NKO PT cells (2.1±0.3-fold increase, p<0.01, n=4). Our data indicate that: 1) PT cells can sense and respond to high glucose by secreting IL-1β and 2) the absence of the ACE N-domain blunts the production of IL-1β through a mechanism that involves AcSDKP accumulation. In conclusion, ACE might contribute to the inflammatory response that underlays diabetic nephropathy independently from angiotensin II generation.


2017 ◽  
Vol 42 (6) ◽  
pp. 2552-2558 ◽  
Author(s):  
Jingsong Liu ◽  
Ying Zhong ◽  
Guoyong Liu ◽  
Xiaobai Zhang ◽  
Bofei Xiao ◽  
...  

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.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Joao Gimenes-Junior ◽  
Nicole Owuar ◽  
Hymavathi Reddy Vari ◽  
Wuyan Li ◽  
Nathaniel Xander ◽  
...  

AbstractForkhead transcription factor class O (FOXO)3a, which plays a critical role in a wide variety of cellular processes, was also found to regulate cell-type-specific antiviral responses. Airway epithelial cells express FOXO3a and play an important role in clearing rhinovirus (RV) by mounting antiviral type I and type III interferon (IFN) responses. To elucidate the role of FOXO3a in regulating antiviral responses, we generated airway epithelial cell-specific Foxo3a knockout (Scga1b1-Foxo3a−/−) mice and a stable FOXO3a knockout human airway epithelial cell line. Compared to wild-type, Scga1b1-Foxo3a−/− mice show reduced IFN-α, IFN-β, IFN-λ2/3 in response to challenge with RV or double-stranded (ds)RNA mimic, Poly Inosinic-polycytidylic acid (Poly I:C) indicating defective dsRNA receptor signaling. RV-infected Scga1b1-Foxo3a−/− mice also show viral persistence, enhanced lung inflammation and elevated pro-inflammatory cytokine levels. FOXO3a K/O airway epithelial cells show attenuated IFN responses to RV infection and this was associated with conformational change in mitochondrial antiviral signaling protein (MAVS) but not with a reduction in the expression of dsRNA receptors under unstimulated conditions. Pretreatment with MitoTEMPO, a mitochondrial-specific antioxidant corrects MAVS conformation and restores antiviral IFN responses to subsequent RV infection in FOXO3a K/O cells. Inhibition of oxidative stress also reduces pro-inflammatory cytokine responses to RV in FOXO3a K/O cells. Together, our results indicate that FOXO3a plays a critical role in regulating antiviral responses as well as limiting pro-inflammatory cytokine expression. Based on these results, we conclude that FOXO3a contributes to optimal viral clearance and prevents excessive lung inflammation following RV infection.


2022 ◽  
Vol 12 (1) ◽  
pp. 71-80
Author(s):  
Ting Liu ◽  
Jie Chen ◽  
Yiying Ying ◽  
Ling Shi ◽  
Zhengyue Chen

This research aimed to study the inhibitory effect of Glurenorm (gliquidone) on epithelial-to-mesenchymal-transition (EMT) of renal tubular epithelial cells based on the diabetic nephropathy (DN) model. In this study, 30 specific pathogen-free (SPF) mice were selected to construct DN model and randomly rolled into groups A, B, and C, with 10 mice in each group. Low-dose, mediumdose, and high-dose Glurenorm were administered intragastrically. The results showed that the serum urea nitrogen content (7.23±0.39 mmol/L, 6.18±0.46 mmol/L) of control and C group was considerably inferior to A group (8.01±0.48 mmol/L), and the content of C group was greatly lower than controls (P < 0.05). The creatinine clearance rate (2.97±0.44 mL/min, 4.02±0.31 mL/min) of mice in control and C group was notably superior to A group (2.18±0.38 mL/min), and that of C group was obviously higher versus controls (P < 0.05). After 5 weeks of intragastric intervention by Glurenorm, the body mass of the mice in control and C group was evidently lower relative to A group, and that of C group was obviously higher versus controls (P < 0.05). Mice in control and C group were remarkably lower in body mass at the 7th week after Glurenorm intervention versus A group, and C group was relatively lower versus controls (P < 0.05). In short, EMT played an important role in promoting the occurrence and progression of renal fibrosis. Glurenorm can reduce the progression of renal fibrosis, inhibit EMT of renal tubular epithelial cells, and effectively protect kidney function.


2010 ◽  
Vol 316 (19) ◽  
pp. 3282-3291 ◽  
Author(s):  
Kazuhiro Okano ◽  
Yuki Tsuruta ◽  
Tetsuri Yamashita ◽  
Mari Takano ◽  
Yoshihisa Echida ◽  
...  

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0252761
Author(s):  
Shaoqiang Wang ◽  
Pengfei Yi ◽  
Na Wang ◽  
Min Song ◽  
Wenhui Li ◽  
...  

Long non-coding RNAs (lncRNAs) are important regulators in diabetic nephropathy. In this study, we investigated the potential role of lncRNA TUG1 in regulating endoplasmic reticulum stress (ERS)-mediated apoptosis in high glucose induced renal tubular epithelial cells. Human renal tubular epithelial cell line HK-2 was challenged with high glucose following transfection with lncRNA TUG1, miR-29c-3p mimics or inhibitor expression plasmid, either alone or in combination, for different experimental purposes. Potential binding effects between TUG1 and miR-29c-3p, as well as between miR-29c-3p and SIRT1 were verified. High glucose induced apoptosis and ERS in HK-2 cells, and significantly decreased TUG1 expression. Overexpressed TUG1 could prevent high glucose-induced apoptosis and alleviated ERS via negatively regulating miR-29c-3p. In contrast, miR-29c-3p increased HK-2 cells apoptosis and ERS upon high glucose-challenge. SIRT1 was a direct target gene of miR-29c-3p in HK-2 cells, which participated in the effects of miR-29c-3p on HK-2 cells. Mechanistically, TUG1 suppressed the expression of miR-29c-3p, thus counteracting its function in downregulating the level of SIRT1. TUG1 regulates miR-29c-3p/SIRT1 and subsequent ERS to relieve high glucose induced renal epithelial cells injury, and suggests a potential role for TUG1 as a promising diagnostic marker of diabetic nephropathy.


2018 ◽  
Vol 29 (10) ◽  
pp. 2493-2509 ◽  
Author(s):  
Siu Chiu Chan ◽  
Ying Zhang ◽  
Annie Shao ◽  
Svetlana Avdulov ◽  
Jeremy Herrera ◽  
...  

BackgroundMutation of HNF1B, the gene encoding transcription factor HNF-1β, is one cause of autosomal dominant tubulointerstitial kidney disease, a syndrome characterized by tubular cysts, renal fibrosis, and progressive decline in renal function. HNF-1β has also been implicated in epithelial–mesenchymal transition (EMT) pathways, and sustained EMT is associated with tissue fibrosis. The mechanism whereby mutated HNF1B leads to tubulointerstitial fibrosis is not known.MethodsTo explore the mechanism of fibrosis, we created HNF-1β–deficient mIMCD3 renal epithelial cells, used RNA-sequencing analysis to reveal differentially expressed genes in wild-type and HNF-1β–deficient mIMCD3 cells, and performed cell lineage analysis in HNF-1β mutant mice.ResultsThe HNF-1β–deficient cells exhibited properties characteristic of mesenchymal cells such as fibroblasts, including spindle-shaped morphology, loss of contact inhibition, and increased cell migration. These cells also showed upregulation of fibrosis and EMT pathways, including upregulation of Twist2, Snail1, Snail2, and Zeb2, which are key EMT transcription factors. Mechanistically, HNF-1β directly represses Twist2, and ablation of Twist2 partially rescued the fibroblastic phenotype of HNF-1β mutant cells. Kidneys from HNF-1β mutant mice showed increased expression of Twist2 and its downstream target Snai2. Cell lineage analysis indicated that HNF-1β mutant epithelial cells do not transdifferentiate into kidney myofibroblasts. Rather, HNF-1β mutant epithelial cells secrete high levels of TGF-β ligands that activate downstream Smad transcription factors in renal interstitial cells.ConclusionsAblation of HNF-1β in renal epithelial cells leads to the activation of a Twist2-dependent transcriptional network that induces EMT and aberrant TGF-β signaling, resulting in renal fibrosis through a cell-nonautonomous mechanism.


eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Ce Zhang ◽  
Yue Chen ◽  
Shijin Sun ◽  
Yikai Zhang ◽  
Lina Wang ◽  
...  

Selective protein distribution on distinct plasma membranes is important for epithelial cell function. To date, how proteins are directed to specific epithelial cell surface is not fully understood. Here we report a conserved DSSDE motif in LDL-receptor (LDLR) modules of corin (a transmembrane serine protease) and CD320 (a receptor for vitamin B12 uptake), which regulates apical membrane targeting in renal epithelial cells. Altering this motif prevents specific apical corin and CD320 expression in polarized Madin–Darby canine kidney (MDCK) cells. Mechanistic studies indicate that this DSSDE motif participates in a Rab11a-dependent mechanism that specifies apical sorting. In MDCK cells, inhibition of Rab11a, but not Rab11b, expression leads to corin and CD320 expression on both apical and basolateral membranes. Together, our results reveal a novel molecular recognition mechanism that regulates LDLR module-containing proteins in their specific apical expression in polarized renal epithelial cells.


2019 ◽  
Author(s):  
Dongsheng Cheng ◽  
Rulian Liang ◽  
Baorui Huang ◽  
Jiasheng Hou ◽  
Jianyong Yin ◽  
...  

Abstract Background Tubular injury plays a critical role in the development of diabetic nephropathy (DN), but current DN therapies do not combat tubular injury. This study was conducted to investigate if tumor necrosis factor (TNF)-α inhibition protects against tubular injury in diabetic rats and to examine the associated mechanisms. Methods Kidney biopsy tissues were collected and analyzed from 12 patients with DN and 5 control subjects. Streptozotocin (STZ)-induced diabetic rats were treated with a TNF-α inhibitor for 12 weeks. Renal function, albuminuria, histological injury, renal TNF-α messenger RNA (mRNA) and the NOD- (nucleotide-binding), LRR- (domain-like receptor) and pyrin domain-containing protein 3 (NLRP3) inflammasome were assessed. Results Diabetic patients with tubulointerstitial injury (TIN) presented with higher renal tubular expression of TNF-α mRNA and the NLRP3 inflammasome (P < 0.05). TNF-α inhibition reduced albuminuria, glomerular injury and tubular injury in STZ-induced diabetic rats (P < 0.05). Importantly, TNF-α inhibition significantly reduced the NLRP3 inflammasome in tubules (P < 0.05). Moreover, TNF-α inhibition decreased expression of tubular interleukin (IL)-6 and IL-17A mRNA. Conclusions TNF-α inhibition protects against TIN by suppressing the NLRP3 inflammasome in DN rats. Future studies may focus on the clinical protective effects of TNF-α inhibition using prospective observation.


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