scholarly journals Endogenous Relaxin Is a Naturally Occurring Modulator of Experimental Renal Tubulointerstitial Fibrosis

Endocrinology ◽  
2007 ◽  
Vol 148 (2) ◽  
pp. 660-669 ◽  
Author(s):  
Tim D. Hewitson ◽  
Ishanee Mookerjee ◽  
Rosemary Masterson ◽  
Chongxin Zhao ◽  
Geoffrey W. Tregear ◽  
...  

Relaxin is a naturally occurring regulator of collagen turnover. In this study, we determined the role of endogenous relaxin in the pathogenesis of primary tubulointerstitial fibrosis after unilateral ureteric obstruction (UUO). Four- to 6-wk-old relaxin (RLX) gene-knockout (RLX−/−) and age-matched wild-type (RLX+/+) mice, with equivalent baseline collagen levels, were subjected to UUO. Obstructed and contralateral kidneys were collected at d 0, 3, and 10 after surgery and analyzed for changes in inflammatory and fibrosis-related markers. UUO was associated with a progressive increase in fibrosis in all obstructed, but not contralateral kidneys. The increase in total collagen (hydroxyproline analysis) was associated with more α-smooth muscle actin (α-SMA) staining (myofibroblasts) and interstitial collagen sub-types (SDS-PAGE; types I, III, and V), whereas gelatin zymography demonstrated increased expression of matrix metalloproteinase-2 after surgery. By d 10 after UUO, there was a 5-fold decrease in RLX mRNA expression (quantitative RT-PCR) in RLX+/+ animals. Total collagen and α-SMA expression were significantly greater in the obstructed kidneys of RLX−/− mice 3 d after UUO (both P < 0.05 vs. RLX+/+ D3 after UUO), but comparable to that in RLX+/+ animals 10 d after UUO. Administration of recombinant H2 relaxin to RLX−/− mice 4 d before UUO ameliorated the increase in collagen and α-SMA expression (both P < 0.05 vs. untreated RLX−/− mice) by d 3 after UUO. Expression of monocyte chemoattractant protein-1 and macrophage infiltration (inflammation) in addition to that of matrix metalloproteinases was unaffected by genotype after UUO. These combined data demonstrate that endogenous RLX acts as a modulating factor in tubulointerstitial fibrosis, a hallmark of progressive renal disease. This is likely to be via direct effects on renal myofibroblast function.

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Yun Liu ◽  
Sujun Zuo ◽  
Xiaoyan Li ◽  
Jinjin Fan ◽  
Xueqin Cao ◽  
...  

Abstract To investigate the levels of (Pro) renin receptor [(P) RR], α-smooth muscle actin (α-SMA), fibronectin (FN), and vacuolar H+-ATPase (V-ATPase) subunits (B2, E, and c) in rat unilateral ureteral obstruction (UUO) models and rat proximal tubular epithelial cells (NRK-52E) treated with prorenin to elucidate the role of V-ATPase in these processes by activating the (P) RR. UUO significantly upregulated (P) RR, V-ATPase subunits, α-SMA and FN expression in tubulointerstitium or tubular epithelial cells. A marked colocalization of (P) RR and the B2 subunit was also observed. Prorenin treatment upregulated α-SMA, FN, (P) RR, and V-ATPase subunits and activity in NRK52E cell in a dose- and time-dependent manner. The V-ATPase inhibitor bafilomycin A1 partially blocked prorenin-induced (P) RR, FN, and α-SMA expression. Co-immunoprecipitate and immunofluorescence results demonstrated that the V-ATPase B2 subunit bound to the (P) RR, which was upregulated after prorenin stimulation. Either siRNA-mediated (P) RR or B2 subunit knockdown partially reduced V-ATPase activity and attenuated prorenin-induced FN and α-SMA expression. From the data we can assume that activation of (P) RR and V-ATPase may play an important role in tubulointerstitial fibrosis with possible involvement of interaction of V-ATPase B2 subunit and (P)RR.


2020 ◽  
Vol 11 ◽  
Author(s):  
Qin Dai ◽  
Yan Zhang ◽  
Xiaohua Liao ◽  
Yupeng Jiang ◽  
Xin Lv ◽  
...  

Cell death and sterile inflammation are major mechanisms of renal fibrosis, which eventually develop into end-stage renal disease. “Necroptosis” is a type of caspase-independent regulated cell death, and sterile inflammatory response caused by tissue injury is strongly related to necrosis. Fluorofenidone (AKF-PD) is a novel compound shown to ameliorate renal fibrosis and associated inflammation. We investigated whether AKF-PD could alleviate renal fibrosis by inhibiting necroptosis. Unilateral ureteral obstruction (UUO) was used to induce renal tubulointerstitial fibrosis in C57BL/6J mice. AKF-PD (500 mg/kg) or necrostatin-1 (Nec-1; 1.65 mg/kg) was administered simultaneously for 3 and 7 days. Obstructed kidneys and serum were harvested after euthanasia. AKF-PD and Nec-1 ameliorated renal tubular damage, inflammatory-cell infiltration, and collagen deposition, and the expression of proinflammatory factors (interlukin-1β, tumor necrosis factor [TNF]-α) and chemokines (monocyte chemoattractant protein-1) decreased. AKF-PD or Nec-1 treatment protected renal tubular epithelial cells from necrosis and reduced the release of lactate dehydrogenase in serum. Simultaneously, production of receptor-interacting protein kinase (RIPK)3 and mixed lineage kinase domain-like protein (MLKL) was also reduced 3 and 7 days after UUO. AKF-PD and Nec-1 significantly decreased the percentage of cell necrosis, inhibiting the phosphorylation of MLKL and RIPK3 in TNF-α- and Z-VAD–stimulated human proximal tubular epithelial (HK-2) cells. In conclusion, AKF-PD and Nec-1 have effective anti-inflammatory and antifibrotic activity in UUO-induced renal tubulointerstitial fibrosis, potentially mediated by the RIPK3/MLKL pathway.


1998 ◽  
Vol 9 (4) ◽  
pp. 632-642 ◽  
Author(s):  
T D Hewitson ◽  
I A Darby ◽  
T Bisucci ◽  
C L Jones ◽  
G J Becker

Renal tubulointerstitial fibrosis may result from a loss of tubulointerstitial volume, which produces a disproportionate increase in the density of matrix. This study examines the relationship between fibrogenesis and collapse in scar formation after experimental renal infection. Escherichia coli were inoculated into the renal cortex of Sprague Dawley rats, with saline substituted in a control group. Glomerular, tubular, and interstitial profile areas were determined. Density of glomerular profiles was used as a measure of tubulointerstitial collapse. Collagen type I, III, and IV expression was examined by in situ hybridization and immunohistochemistry. Myofibroblasts were identified by alpha smooth muscle actin immunohistochemistry, and matrix metalloproteinase-1 (MMP-1) and MMP-2 were localized with appropriate antisera. Acute interstitial edema was followed by increasing density of glomerular profiles, paralleled by loss of interstitial volume and progressive tubular atrophy. Glomerular profile area remained unchanged. Density of glomerular profiles was not temporally related to myofibroblast accumulation. Procollagen alpha 1(I), alpha 1(III), and alpha 1(IV) transcription was focal, spatially related but temporally ordered. Collagen I, III, and IV immunostaining was increased from days 3, 24, and 100, respectively (P < 0.05 versus day 0 and day 100 saline). However, when corrected for glomerular density, collagen I immunostaining decreased between days 24 and 100, whereas collagen III and IV no longer differed from day 0. MMP staining within the lesion was confined to occasional interstitial and epithelial cells throughout. It is concluded that in this model, contraction and collapse of the tubulointerstitial parenchyma has a greater influence than new collagen production on final fibrotic density.


2019 ◽  
Vol 20 (7) ◽  
pp. 1554 ◽  
Author(s):  
Sungjin Chung ◽  
Soojeong Kim ◽  
Mina Son ◽  
Minyoung Kim ◽  
Eun Koh ◽  
...  

p300/CBP-associated factor (PCAF), a histone acetyltransferase, is involved in many cellular processes such as differentiation, proliferation, apoptosis, and reaction to cell damage by modulating the activities of several genes and proteins through the acetylation of either the histones or transcription factors. Here, we examined a pathogenic role of PCAF and its potential as a novel therapeutic target in the progression of renal tubulointerstitial fibrosis induced by non-diabetic unilateral ureteral obstruction (UUO) in male C57BL/6 mice. Administration of garcinol, a PCAF inhibitor, reversed a UUO-induced increase in the renal expression of total PCAF and histone 3 lysine 9 acetylation and reduced positive areas of trichrome and α-smooth muscle actin and collagen content. Treatment with garcinol also decreased mRNA levels of transforming growth factor-β, matrix metalloproteinase (MMP)-2, MMP-9, and fibronectin. Furthermore, garcinol suppressed nuclear factor-κB (NF-κB) and pro-inflammatory cytokines such as tumor necrosis factor-α and IL-6, whereas it preserved the nuclear expression of nuclear factor erythroid-derived 2-like factor 2 (Nrf2) and levels of Nrf2-dependent antioxidants including heme oxygense-1, catalase, superoxide dismutase 1, and NAD(P)H:quinone oxidoreductase 1. These results suggest that the inhibition of inordinately enhanced PCAF could mitigate renal fibrosis by redressing aberrant balance between inflammatory signaling and antioxidant response through the modulation of NF-κB and Nrf2.


2009 ◽  
Vol 297 (4) ◽  
pp. F895-F903 ◽  
Author(s):  
Won Suk An ◽  
Hyun Ju Kim ◽  
Kyu-Hyang Cho ◽  
Nosratola D. Vaziri

Significant reduction of renal mass initiates a series of hemodynamic and nonhemodynamic events which lead to proteinuria, glomerulosclerosis, tubulointerstitial injury, and end-stage renal failure. Lipid mediators derived from fatty acids participate in regulation of renal hemodynamic and nonhemodynamic processes that influence progression of renal disease. Composition of cellular fatty acids and hence related signaling responses are influenced by their dietary contents. Consumption of omega-3 fatty acids (O-3FA) has proven effective in mitigating atherosclerosis. We tested the hypothesis that O-3FA supplementation may retard progression and attenuate upregulation of pathways involved in oxidative stress, inflammation, and fibrosis in rats with renal mass reduction. Sprague-Dawley rats were subjected to 5/6 nephrectomy [chronic renal failure (CRF)] and randomly assigned to the untreated and O-3FA-treated (0.3 g·kg−1·day−1 by gastric gavage for 12 wk) groups. Sham-operated rats served as controls. The untreated CRF rats exhibited proteinuria, hypertension, azotemia, upregulations of renal tissue NAD(P)H oxidase, MCP-1, COX-2, PAI-1, TGF-β, Smad2, α-smooth muscle actin, fibronectin, and hepatocyte growth factor, activation of ERK1/2 and NF-κB, downregulation of Smad7, intense mononuclear leukocyte infiltration, tubulointerstitial fibrosis, and glomerulosclerosis. O-3FA supplementation significantly lowered COX-2, NAD(P)H oxidase (NOX-4, gp91phox, p47phox, p22phox), PAI-1, TGF-β, connective tissue growth factor, α-smooth muscle actin, fibronectin, Smad2, and MCP-1, raised Smad7, and attenuated ERK1/2 and NF-κB activation, tubulointerstitial fibrosis, and inflammation. Thus, long-term O-3FA supplementation can reduce or reverse upregulation of prooxidant, proinflammatory, and profibrotic pathways and attenuate tubulointerstitial fibrosis in the remnant kidney.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Binbin Zheng ◽  
Hongbo Yang ◽  
Jianan Zhang ◽  
Xueli Wang ◽  
Hao Sun ◽  
...  

Acute lung injury (ALI) is one of the fatal symptoms of sepsis. However, there were no effective clinical treatments. TF accumulation-induced fibrin deposit formations and coagulation abnormalities in pulmonary vessels contribute to the lethality of ALI. Suppressor of cytokine signaling 3 (SOCS3) acts as an endogenous negative regulator of the TLR4/TF pathway. We hypothesized that inducing SOCS3 expression using lidocaine to suppress the TLR4/TF pathway may alleviate ALI. Hematoxylin and eosin (H&E), B-mode ultrasound, and flow cytometry were used to measure the pathological damage of mice. Gelatin zymography was used to measure matrix metalloproteinase-2/9 (MMP-2/9) activities. Western blot was used to assay the expression of protein levels. Here, we show that lidocaine could increase the survival rate of ALI mice and ameliorate the lung injury of ALI mice including reducing the edema, neutrophil infiltration, and pulmonary thrombosis formation and increasing blood flow velocity. Moreover, in vitro and in vivo, lidocaine could increase the expression of p-AMPK and SOCS3 and subsequently decrease the expression of p-ASK1, p-p38, TF, and the activity of MMP-2/9. Taken together, our study demonstrated that lidocaine could inhibit the TLR4/ASK1/TF pathway to alleviate ALI via activating AMPK-SOCS3 axis.


2009 ◽  
Vol 88 (8) ◽  
pp. 757-761 ◽  
Author(s):  
K. Jinno ◽  
T. Takahashi ◽  
K. Tsuchida ◽  
E. Tanaka ◽  
K. Moriyama

Wound healing is a well-orchestrated complex process leading to the repair of injured tissues. It is suggested that transforming growth factor (TGF)-β/Smad3 signaling is involved in wound healing. The purpose of this study was to investigate the role of TGF-β/Smad3 signaling in palatal wound healing in Smad3-deficient (Smad3−/−) mice. Histological examination showed that wound closure was accelerated by the proliferation of epithelium and dermal cells in Smad3−/− mice compared with wild-type (WT) mice. Macrophage/monocyte infiltration at wounded regions in Smad3−/− mice was decreased in parallel with the diminished production of TGF-β1, monocyte chemoattractant protein-1, and macrophage inflammatory protein-1α compared with WT mice. Fibrocytes, expressing hematopoietic surface marker and fibroblast products, were recruited and produced α-smooth-muscle actin in WT mice, but were not observed in Smad3−/− mice. These results suggest that TGF-β/Smad3 signaling may play an important role in the regulation of palatal wound healing.


2014 ◽  
Vol 27 (1) ◽  
pp. 97-103 ◽  
Author(s):  
Takahiro Yuasa ◽  
Ryo Yano ◽  
Takeshi Izawa ◽  
Mitsuru Kuwamura ◽  
Jyoji Yamate

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