scholarly journals NLRP3 Deficiency Attenuates Renal Fibrosis and Ameliorates Mitochondrial Dysfunction in a Mouse Unilateral Ureteral Obstruction Model of Chronic Kidney Disease

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Honglei Guo ◽  
Xiao Bi ◽  
Ping Zhou ◽  
Shijian Zhu ◽  
Wei Ding

Background and Aims. The nucleotide-binding domain and leucine-rich repeat containing PYD-3 (NLRP3) inflammasome has been implicated in the pathogenesis of chronic kidney disease (CKD); however, its exact role in glomerular injury and tubulointerstitial fibrosis is still undefined. The present study was performed to identify the function of NLRP3 in modulating renal injury and fibrosis and the potential involvement of mitochondrial dysfunction in the murine unilateral ureteral obstruction (UUO) model of CKD. Methods. Employing wild-type (WT) and NLRP3−/− mice with or without UUO, we evaluated renal structure, tissue injury, and mitochondrial ultrastructure, as well as expression of some vital molecules involved in the progression of fibrosis, apoptosis, inflammation, and mitochondrial dysfunction. Results. The severe glomerular injury and tubulointerstitial fibrosis induced in WT mice by UUO was markedly attenuated in NLRP3−/− mice as evidenced by blockade of extracellular matrix deposition, decreased cell apoptosis, and phenotypic alterations. Moreover, NLRP3 deletion reversed UUO-induced impairment of mitochondrial morphology and function. Conclusions. NLRP3 deletion ameliorates mitochondrial dysfunction and alleviates renal fibrosis in a murine UUO model of CKD.

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Pei-Zhen Cai ◽  
SZU-YU PAN ◽  
SHUEI-LIONG LIN

Abstract Background and Aims Stabilizers of hypoxia-inducible factor (HIF) have been shown to be effective on treatment of anemia in patients with chronic kidney disease (CKD). Increased erythropoietin (EPO) production and enhanced erythropoiesis are known to be the major mechanisms responsible for the treatment effects. However, the effect of HIF stabilization on renal fibrosis is controversial. We created animal models characterized by CKD and pericyte-specific stabilization of HIF to examine the effects of HIF on renal fibrosis and erythropoiesis. Method Gli1CreERT2/+;Egln1F/F, Gli1CreERT2/+;VhlF/F, and Gli1CreERT2/+;Hif1aF/F;Hif2aF/F mice were generated to study the effects of pericyte-specific overexpression or knockout of Hif. Unilateral ureteral obstruction (UUO) was used to induce CKD. The severity of fibrosis was determined by Picrosirius red stain and Col1a1 mRNA level in the kidney. Results Pericyte-specific stabilization of HIF resulted in increased serum EPO level, augmented splenic erythropoiesis, and polycythemia, while the severity of renal fibrosis was not affected. In line with these findings, pericyte-specific knockout of Hif1a or Hif2a did not result in significant change of renal fibrosis. Conclusion Our study endorses the neutral effects of pericyte-specific HIF stabilization on renal fibrosis.


2010 ◽  
Vol 298 (4) ◽  
pp. F1024-F1032 ◽  
Author(s):  
Tipu S. Puri ◽  
Mohammed I. Shakaib ◽  
Anthony Chang ◽  
Liby Mathew ◽  
Oladunni Olayinka ◽  
...  

Chronic kidney disease (CKD) begins with renal injury; the progression thereafter depends upon a number of factors, including genetic background. Unilateral ureteral obstruction (UUO) is a well-described model of renal fibrosis and as such is considered a model of CKD. We used an improved reversible unilateral ureteral obstruction (rUUO) model in mice to study the strain dependence of development of CKD after obstruction-mediated injury. C57BL/6 mice developed CKD after reversal of three or more days of ureteral obstruction as assessed by blood urea nitrogen (BUN) measurements (>40 mg/dl). In contrast, BALB/c mice were resistant to CKD with up to 10 days ureteral obstruction. During rUUO, C57BL/6 mice exhibited pronounced inflammatory and intrinsic proliferative cellular responses, disruption of renal architecture, and ultimately fibrosis. By comparison, BALB/c mice had more controlled and measured extrinsic and intrinsic responses to injury with a return to normal within several weeks after release of ureteral obstruction. Our findings provide a model that allows investigation of the genetic basis of events during recovery from injury that contribute to the development of CKD.


Author(s):  
A. Stavniichuk ◽  
O. Savchuk ◽  
Abdul Hye Khan ◽  
Wojciech K. Jankiewicz ◽  
John D. Imig ◽  
...  

Kidney fibrosis is a key event in the development of chronic kidney disease, leading to end-stage renal failure. Unfortunately, there are now few drugs capable of preventing fibrosis in the kidneys, which is accompanied by the progression of chronic kidney disease in the terminal stage of renal failure. The results show the effectiveness of the use of a new dual-acting agent DM509 in the prevention of renal fibrosis using a model of unilateral obstruction of the ureter in mice. DM509 is both a farnesoid X-receptor agonist and a soluble epoxyhydrolase inhibitor. In this study, there were 8-12 week old C57BL/6J males undergoing surgery, which led to the development of unilateral ureteral obstruction and a control group. Mice received DM509 (10 mg/kg/day) or DM509-free solution together with drinking water for 10 days the day before surgery. Samples of kidney and blood tissues were collected at the end of the experiment. In the unilateral ureteral obstruction group, kidney dysfunction was detected, which was accompanied by increased urea nitrogen content in the blood compared to the control group (63 ± 7 vs. 34 ± 6 mg/d). The reduction of urea nitrogen in the blood by 36 % in mice with unilateral ureteral obstruction treated with DM509 is shown compared to mice with this pathology without treatment, which in turn proved the effectiveness of DM509 in preventing renal dysfunction. In mice with unilateral ureteral obstruction, which did not receive DM509, the development of kidney fibrosis with a high content of hydroxyproline in the kidneys and also increased collagen content in histological sections of the kidneys were detected. In the DM509 group, the renal and collagen hydroxyproline content was 34-66 % lower, indicating the effectiveness of this agent in the treatment of renal fibrosis. Thus, we have shown that the new DM509 is effective in preventing renal dysfunction and renal fibrosis using a murine model of unilateral ureteral obstruction.


2020 ◽  
Vol 318 (5) ◽  
pp. F1160-F1166
Author(s):  
Fitra Rianto ◽  
Akihiro Kuma ◽  
Carla L. Ellis ◽  
Faten Hassounah ◽  
Eva L. Rodriguez ◽  
...  

Renal fibrosis is a major contributor to the development and progression of chronic kidney disease. A low-protein diet can reduce the progression of chronic kidney disease and reduce the development of renal fibrosis, although the mechanism is not well understood. Urea reabsorption into the inner medulla is regulated by inner medullary urea transporter (UT)-A1 and UT-A3. Inhibition or knockout of UT-A1/A3 will reduce interstitial urea accumulation, which may be beneficial in reducing renal fibrosis. To test this hypothesis, the effect of unilateral ureteral obstruction (UUO) was compared in wild-type (WT) and UT-A1/A3 knockout mice. UUO causes increased extracellular matrix associated with increases in transforming growth factor-β, vimentin, and α-smooth muscle actin (α-SMA). In WT mice, UUO increased the abundance of three markers of fibrosis: transforming growth factor-β, vimentin, and α-SMA. In contrast, in UT-A1/A3 knockout mice, the increase following UUO was significantly reduced. Consistent with the Western blot results, immunohistochemical staining showed that the levels of vimentin and α-SMA were increased in WT mice with UUO and that the increase was reduced in UT-A1/A3 knockout mice with UUO. Masson’s trichrome staining showed increased collagen in WT mice with UUO, which was reduced in UT-A1/A3 knockout mice with UUO. We conclude that reduced UT activity reduces the severity of renal fibrosis following UUO.


2013 ◽  
Vol 305 (5) ◽  
pp. F618-F627 ◽  
Author(s):  
Shenyang Li ◽  
Nithya Mariappan ◽  
Judit Megyesi ◽  
Brian Shank ◽  
Krishnaswamy Kannan ◽  
...  

We examined the effects of increased expression of proximal tubule peroxisome proliferator-activated receptor (PPAR)α in a mouse model of renal fibrosis. After 5 days of unilateral ureteral obstruction (UUO), PPARα expression was significantly reduced in kidney tissue of wild-type mice but this downregulation was attenuated in proximal tubules of PPARα transgenic (Tg) mice. When compared with wild-type mice subjected to UUO, PPARα Tg mice had reduced mRNA and protein expression of proximal tubule transforming growth factor (TGF)-β1, with reduced production of extracellular matrix proteins including collagen 1, fibronectin, α-smooth muscle actin, and reduced tubulointerstitial fibrosis. UUO-mediated increased expression of microRNA 21 in kidney tissue was also reduced in PPARα Tg mice. Overexpression of PPARα in cultured proximal tubular cells by adenoviral transduction reduced aristolochic acid-mediated increased production of TGF-β, demonstrating PPARα signaling reduces epithelial TGF-β production. Flow cytometry studies of dissociated whole kidneys demonstrated reduced macrophage infiltration to kidney tissue in PPARα Tg mice after UUO. Increased expression of proinflammatory cytokines including IL-1β, IL-6, and TNF-α in wild-type mice was also significantly reduced in kidney tissue of PPARα Tg mice. In contrast, the expression of anti-inflammatory cytokines IL-10 and arginase-1 was significantly increased in kidney tissue of PPARα Tg mice when compared with wild-type mice subjected to UUO. Our studies demonstrate several mechanisms by which preserved expression of proximal tubule PPARα reduces tubulointerstitial fibrosis and inflammation associated with obstructive uropathy.


2016 ◽  
Vol 311 (3) ◽  
pp. F614-F625 ◽  
Author(s):  
Maria Mustafa ◽  
Tony N. Wang ◽  
Xing Chen ◽  
Bo Gao ◽  
Joan C. Krepinsky

Tubulointerstitial fibrosis is a major feature associated with declining kidney function in chronic kidney disease of diverse etiology. No effective means as yet exists to prevent the progression of fibrosis. We have shown that the transcription factor sterol-regulatory element-binding protein 1 (SREBP-1) is an important mediator of the profibrotic response to transforming growth factor-β (TGF-β) and angiotensin II, both key cytokines in the fibrotic process. Here, we examined the role of SREBP in renal interstitial fibrosis in the unilateral ureteral obstruction (UUO) model. The two isoforms of SREBP (-1 and -2) were activated by 3 days after UUO, with SREBP-1 showing a more sustained activation to 21 days. We then examined whether SREBP1/2 inhibition with the small-molecule inhibitor fatostatin could attenuate fibrosis after 14 days of UUO. SREBP activation was confirmed to be inhibited by fatostatin. Treatment decreased interstitial fibrosis, TGF-β signaling, and upregulation of α-smooth muscle actin (SMA), a marker of fibroblast activation. Fatostatin also attenuated inflammatory cell infiltrate and apoptosis. Associated with this, fatostatin preserved proximal tubular mass. The significant increase in atubular glomeruli observed after UUO, known to correlate with irreversible renal functional decline, was also decreased by treatment. In cultured primary fibroblasts, TGF-β1 induced the activation of SREBP-1 and -2. Fatostatin blocked TGF-β1-induced α-SMA and matrix protein upregulation. The inhibition of SREBP is thus a potential novel therapeutic target in the treatment of fibrosis in chronic kidney disease.


2008 ◽  
Vol 294 (3) ◽  
pp. F508-F517 ◽  
Author(s):  
Lin Wang ◽  
Ji-Yang Sophie Lee ◽  
Joon Hyeok Kwak ◽  
Yanjuan He ◽  
Sung Il Kim ◽  
...  

Tubulointerstitial fibrosis is a hallmark of chronic progressive kidney disease leading to end-stage renal failure. An endogenous product of heme oxygenase activity, carbon monoxide (CO), has been shown to exert cytoprotection against tissue injury. Here, we explored the effects of exogenous administration of low-dose CO in an in vivo model of renal fibrosis induced by unilateral ureteral obstruction (UUO) and examined whether CO can protect against kidney injury. UUO in mice leads to increased extracellular matrix (ECM) deposition and tubulointerstitial fibrosis within 4 to 7 days. Kidneys of mice exposed to low-dose CO, however, had markedly reduced ECM deposition after UUO. Moreover, low-dose CO treatment inhibited the induction of α-smooth muscle actin (α-SMA) and major ECM proteins, type 1 collagen and fibronectin, in kidneys after UUO. In contrast, these anti-fibrotic effects of CO treatment were abrogated in mice carrying null mutation of Mkk3, suggesting involvement of the MKK3 signaling pathway in mediating the CO effects. Additionally, in vitro CO exposure markedly inhibited TGF-β1-induced expression of α-SMA, collagen, and fibronectin in renal proximal tubular epithelial cells. Our findings suggest that low-dose CO exerts protective effects, via the MKK3 pathway, to inhibit development of renal fibrosis in obstructive nephropathy.


Background: Obstructive nephropathy can lead to progressive and permanent loss of kidney function characterized by interstitial inflammation and tubulointerstitial fibrosis. Tubulointerstitial fibrosis presents as the end result of various kidney injuries in general and can cause chronic kidney disease (CKD), which can progress to end-stage kidney disease and hypertension. Objective: This study aimed to determine the effectiveness of unilateral ureteral obstruction (UUO) as a model of renal fibrosis and hypertension. Method: Sixteen male Rattus norvegicus mice (150-200 g) were divided into control groups and UUO by ureteral ligation, eight mice each. The systolic blood pressure (SBP) were measured every seven days. After 30 days the animals were dissected to analyze the changes in renal interstitial fibrosis. Statistical analysis was carried out by unpaired t test or alternative test. Results: There was a significant increase in interstitial fibrosis in the UUO rat group [1% (0% - 5%) vs. 75% (20% - ­90%), p <0.001] and SBP [85.38 ± 1.69 mmHg vs 144.75 ± 4.27 mmHg, p <0.001]. Conclusion: UUO can be used as a model of fibrosis and hypertension, which can be used as the basis for the development of anti-fibrotic and anti-hypertensive drugs.


2013 ◽  
Vol 304 (4) ◽  
pp. F432-F439 ◽  
Author(s):  
Wassim Chaabane ◽  
Françoise Praddaude ◽  
Marie Buleon ◽  
Acil Jaafar ◽  
Marion Vallet ◽  
...  

Murine unilateral ureteral obstruction (UUO), a major model of progressive kidney disease, causes loss of proximal tubular mass and formation of atubular glomeruli. Adult C57BL/6 mice underwent a sham operation or reversible UUO under anesthesia. In group 1, kidneys were harvested after 7 days. In group 2, the obstruction was released after 7 days, and a physiological study of both kidneys was performed 30 days later. Renal blood flow (RBF), glomerular filtration rate (GFR), urine protein, and albumin excretion were measured after ligation of either the left or right ureter. Glomerular volume (periodic acid-Schiff), glomerulotubular integrity and proximal tubular mass ( Lotus tetragonolobus lectin), and interstitial collagen (Sirius red) were measured by histomorphometry. Obstructed kidney weight was reduced by 15% at 7 days but was not different from sham after a 30-day recovery. Glomerular volume and proximal tubular area of the obstructed kidney were reduced by 55% at 7 days, but normalized after 30 days. Interstitial collagen deposition increased 2.4-fold after 7 days of UUO and normalized after release. However, GFR and RBF were reduced by 40% and urine albumin/protein ratio was increased 2.8-fold 30 days after release of UUO. This was associated with a 50% reduction in glomerulotubular integrity despite a 30-day recovery ( P < 0.05 for all data). We conclude that release of 7-day UUO can arrest progression but does not restore normal function of the postobstructed kidney. Although the remaining intact nephrons have hypertrophied, glomerular injury is revealed by albuminuria. These results suggest that glomerulotubular injury should become the primary target of slowing progressive kidney disease.


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