scholarly journals SO041THE EFFECT AND MECAHNISM OF THE LOX IN AT1R/Β-ARRESTIN BIASED PATHWAY INDUCED RENAL INTERSTITIAL FIBROSIS

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Xiaoqin Zhang ◽  
Chen Yu

Abstract Background and Aims We studied the downstream and mechanism of β-arrestins signaling in renal fibrosis process and the role of lysyl oxidase (LOX) in the AT1R-β-arrestins pathway. Method The mechanism of β-arrestins signaling was studied in normal rat kidney tubule epithelial cells (NRK-52E) treated with SII in vitro. BAPN or placebo was administered during ischemia reperfusion (IR)-induced fibrosis progression. Collagen crosslinking and fibrosis progression were assessed histologically and biochemically. Results The mRNA and protein levels of β-arrestin-1 and β-arrestin-2 were significantly upregulated in renal fibrosis model both in vitro and in vivo. SII activated the ERK-STAT3 PY705 but not STAT3-Try727 in nucleus of NRK-52E cells, which effects were abolished when transfection of siRNA targeting β-arrestin-1 and β-arrestin-2 or pretreated with PD98059 (MEK inhibitor). LOX was strongly induced in fibrotic kidney and NRK-52E cells treated with SII. Active LOX significantly increased collagen crosslinking. In established IR-28d renal fibrosis, LOX inhibition promoted fibrosis reversal and with a 25% decrease insoluble collagen. Gene silencing of β-arrestin-1 + 2 or STAT3 apparently inhibited SII-induced LOX expression in vitro. Besides, chromatin immunoprecipitation (ChIP) assay clearly demonstrating the interaction between STAT3 and the LOX promoter, which indicated LOX is a direct target gene of SII-β-arrestins-STAT3 signaling. Conclusion The ERK/STAT3 was downstream of AT1R-β-arrestins, ERK entered the nucleus and activated STAT3-PY705. LOX mediates collagen crosslinking and fibrotic matrix stabilization during renal fibrosis via the AT1R-β-arrestins-ERK-STAT3-PY705 signaling. By blocking this profibrotic pathway, therapeutic LOX inhibition attenuates the fibrosis and suggesting target the LOX has significant potency for the treatment of patients with fibrotic kidney disorders.

2016 ◽  
Vol 130 (19) ◽  
pp. 1727-1739 ◽  
Author(s):  
Akiko Tanino ◽  
Takafumi Okura ◽  
Tomoaki Nagao ◽  
Masayoshi Kukida ◽  
Zuowei Pei ◽  
...  

Interleukin (IL)-18 is a member of the IL-1 family of cytokines and was described originally as an interferon γ-inducing factor. Aldosterone plays a central role in the regulation of sodium and potassium homoeostasis by binding to the mineralocorticoid receptor and contributes to kidney and cardiovascular damage. Aldosterone has been reported to induce IL-18, resulting in cardiac fibrosis with induced IL-18-mediated osteopontin (OPN). We therefore hypothesized that aldosterone-induced renal fibrosis via OPN may be mediated by IL-18. To verify this hypothesis, we compared mice deficient in IL-18 and wild-type (WT) mice in a model of aldosterone/salt-induced hypertension. IL-18−/− and C57BL/6 WT mice were used for the uninephrectomized aldosterone/salt hypertensive model, whereas NRK-52E cells (rat kidney epithelial cells) were used in an in vitro model. In the present in vivo study, IL-18 protein expression was localized in medullary tubules in the WT mice, whereas in aldosterone-infused WT mice this expression was up-regulated markedly in the proximal tubules, especially in injured and dilated tubules. This renal damage caused by aldosterone was attenuated significantly by IL-18 knockout with down-regulation of OPN expression. In the present in vitro study, aldosterone directly induced IL-18 gene expression in renal tubular epithelial cells in a concentration- and time-dependent manner. These effects were inhibited completely by spironolactone. IL-18 may be a key mediator of aldosterone-induced renal fibrosis by inducing OPN, thereby exacerbating renal interstitial fibrosis. Inhibition of IL-18 may therefore provide a potential target for therapeutic intervention aimed at preventing the progression of renal injury.


2020 ◽  
Vol 48 (07) ◽  
pp. 1715-1729
Author(s):  
Yanhuan Feng ◽  
Fan Guo ◽  
Hongxia Mai ◽  
Jing Liu ◽  
Zijing Xia ◽  
...  

Pterostilbene (PTB) is a derivative of resveratrol present in grapes and blueberries. PTB is structurally similar to resveratrol, possessing properties such as being analgesic, anti-aging, antidiabetic, anti-inflammatory, anti-obesity, anti-oxidation, cholesterol-reductive, and neuroprotective. However, there have not been reports on the effect of PTB on macrophage-myofibroblast transition (MMT) induced fibrosis in kidney. In this study, we investigated the antifibrotic effects of PTB on the in vivo mouse unilateral ureteral obstruction (UUO) model and in vitro MMT cells. Kidneys subjected to UUO with PTB treatment were collected for the investigation of PTB mediating MMT derived renal interstitial fibrosis. We conducted kidney RNA-seq transcriptomes and TGF-[Formula: see text]1-induced bone marrow-derived macrophages assays to determine the mechanisms of PTB. We found that PTB treatment suppressed the interstitial fibrosis in UUO mice. PTB also attenuated the number of MMT cells in vivo and in vitro. The transcriptomic analysis showed that CXCL10 may play a central role in the process of PTB-treated renal fibrosis. The siRNA-mediated CXCL10 knockdown decreased the number of MMT cells in TGF-[Formula: see text]1-induced bone marrow-derived macrophages. Our results suggested that PTB attenuated renal interstitial fibrosis by mediating MMT by regulating transcriptional activity of CXCL10.


2020 ◽  
Vol 117 (34) ◽  
pp. 20741-20752 ◽  
Author(s):  
Patrick Ming-Kuen Tang ◽  
Ying-ying Zhang ◽  
Jun Xiao ◽  
Philip Chiu-Tsun Tang ◽  
Jeff Yat-Fai Chung ◽  
...  

Unresolved inflammation can lead to tissue fibrosis and impaired organ function. Macrophage–myofibroblast transition (MMT) is one newly identified mechanism by which ongoing chronic inflammation causes progressive fibrosis in different forms of kidney disease. However, the mechanisms underlying MMT are still largely unknown. Here, we discovered a brain-specific homeobox/POU domain protein Pou4f1 (Brn3a) as a specific regulator of MMT. Interestingly, we found that Pou4f1 is highly expressed by macrophages undergoing MMT in sites of fibrosis in human and experimental kidney disease, identified by coexpression of the myofibroblast marker, α-SMA. Unexpectedly, Pou4f1 expression peaked in the early stage in renal fibrogenesis in vivo and during MMT of bone marrow-derived macrophages (BMDMs) in vitro. Mechanistically, chromatin immunoprecipitation (ChIP) assay identified that Pou4f1 is a Smad3 target and the key downstream regulator of MMT, while microarray analysis defined a Pou4f1-dependent fibrogenic gene network for promoting TGF-β1/Smad3-driven MMT in BMDMs at the transcriptional level. More importantly, using two mouse models of progressive renal interstitial fibrosis featuring the MMT process, we demonstrated that adoptive transfer of TGF-β1-stimulated BMDMs restored both MMT and renal fibrosis in macrophage-depleted mice, which was prevented by silencing Pou4f1 in transferred BMDMs. These findings establish a role for Pou4f1 in MMT and renal fibrosis and suggest that Pou4f1 may be a therapeutic target for chronic kidney disease with progressive renal fibrosis.


RSC Advances ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 5891-5896 ◽  
Author(s):  
Yanhuan Feng ◽  
Jun Xu ◽  
Fan Guo ◽  
Rongshuang Huang ◽  
Min Shi ◽  
...  

The novel small-molecule inhibitor of iNOS (SKLB023) hindered renal interstitial fibrosis in vivo and in vitro by interfering with TGF-β1/Smad3 signaling, highlighting that SKLB023 has potential in the therapeutic strategy for renal fibrosis.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Yan-lin Li ◽  
Lin-na Liu ◽  
Lin Huang ◽  
Hai-wen An ◽  
Jian-lin Jian ◽  
...  

Objective. To investigate the efficacy of Niao Du Kang (NDK) mixture in renal fibrosis of rats and to explore the mechanism underlying the effect of NDK on renal fibrosis. Methods. Unilateral ureteral obstruction (UUO) was used to replicate a rat renal interstitial fibrosis model. The drug-administered groups were given 20 ml/kg (NDK-H), 10 ml/kg (NDK-M), and 5 ml/kg (NDK-L) NDK mixture once a day for 21 days beginning 48 hours after surgery. The 24-hour urine protein and serum creatinine (CR) levels in the sham group rats, UUO rats, and NDK mixture-treated rats were measured after the last administration. The pathological changes of rat kidney tissue were observed by HE staining. The degree of fibrosis was observed by Masson’s staining and scored. The expression levels of TGF-β, α-SMA mRNA, and mir-129-5p in kidney were detected by qRT-PCR. HK-2 cells were treated with 5 ng/ml TGF-β to induce HK-2 cell fibrosis. The expression levels of TGF-β, α-SMA mRNA, and mir-129-5p in HK-2 cells were detected by qRT-PCR. TargetScan predicted the target gene of mir-129-5p, HK-2 cells were transfected with mir-129-5p mimic, and an overexpressed mir-129-5p HK-2 cell model was constructed. qRT-PCR was used to detect the expression of PDPK1 mRNA. Western blot was used to detect the expression of PDPK1, AKT, and p-AKT in HK-2 cells induced by TGF-β and in UUO rats. Results. NDK mixture significantly reduced the 24-hour urine protein and CR levels of UUO rats. HE staining showed that the NDK mixture group exhibited a significantly reduced degree of renal interstitial fibrosis. NDK mixture also reduced the expression of TGF-β and α-SMA, and the middle-dose group showed a better therapeutic effect. In vitro studies showed that NDK mixture-containing serum increased the expression of mir-129-5p to reduce renal fibrosis. In addition, NDK mixture increased the expression of mir-129-5p in vivo. Further studies indicated that mir-129-5p could target PDPKl to reduce its expression. The NDK-containing serum group also exhibited reduced expression of PDPK1. Conclusion. NDK mixture can significantly improve renal function and improve renal fibrosis in UUO model rats. Furthermore, NDK mixture can inhibit the expression of PDPK1 by upregulating the expression of mir-129-5p and then inhibiting the PI3K/AKT pathway to improve renal fibrosis.


2020 ◽  
Vol 51 (11) ◽  
pp. 907-918
Author(s):  
Xiao-qin Zhang ◽  
Xin Li ◽  
Wen-qian Zhou ◽  
Xi Liu ◽  
Jie-li Huang ◽  
...  

<b><i>Background:</i></b> Kidney fibrosis is the ultimate consequence of advanced stages of chronic kidney disease (CKD); however, there are currently no reliable biomarkers or noninvasive diagnostic tests available for the detection of kidney fibrosis. Lysyl oxidase (LOX) promotes collagen cross-linking, and serum LOX levels have been shown to be elevated in patients with fibrosis of the heart, lungs, and liver. However, serum LOX levels have not been reported in patients with kidney fibrosis. We explored whether serum LOX levels are associated with kidney fibrosis. <b><i>Method:</i></b> Overall, 202 patients with kidney disease underwent renal biopsy, scoring of kidney fibrosis, and determination of the area of kidney fibrosis. LOX levels were measured in serum and in kidney tissues. We analyzed the association of circulating LOX and tissue LOX levels with the scores and areas of kidney fibrosis. LOX expression was also investigated with in vitro and in vivo kidney fibrosis models. <b><i>Results:</i></b> Serum LOX levels were higher in patients with kidney fibrosis than in those without kidney fibrosis (<i>p</i> &#x3c; 0.001) and higher in patients with moderate-severe kidney fibrosis than in patients with mild kidney fibrosis (<i>p</i> &#x3c; 0.001). Both serum LOX and renal tissue LOX levels correlated with the area of kidney fibrosis (<i>r</i> = 0.748, <i>p</i> &#x3c; 0.001; <i>r</i> = 0.899, <i>p</i> &#x3c; 0.001, respectively). Receiver operating characteristic curve analysis of serum LOX levels showed an area under the curve of 0.80 (95% CI: 0.74–0.86). The optimal serum LOX level cutoff point was 253.34 pg/mL for the prediction of kidney fibrosis and 306.56 pg/mL for the prediction of moderate-severe kidney fibrosis. LOX expression levels were significantly upregulated (2.3–2.6 and 6-fold, respectively) in in vitro and in vivo interstitial fibrosis models. <b><i>Conclusions:</i></b> Both serum LOX and tissue LOX levels correlated with the presence and degree of kidney fibrosis in patients with CKD. These results suggest that serum LOX levels could potentially serve as a noninvasive diagnostic biomarker for kidney fibrosis and may further potentially serve as a stratified biomarker for the identification of mild and moderate-severe kidney fibrosis.


Open Medicine ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. 1378-1385
Author(s):  
Chen-Min Sun ◽  
Wen-Yi Zhang ◽  
Shu-Yan Wang ◽  
Gang Qian ◽  
Dong-Liang Pei ◽  
...  

Abstract Aim Renal fibrosis (RF) is a common clinical condition leading to irreversible renal function loss. Tyrosine kinase proteins and microRNAs (miRs) are associated with pathogenesis and we aim to investigate the role of Fer and its partner miR(s) in RF. Method In silico reproduction of Mouse Kidney FibrOmics browser was performed to identify potential miR(s) and target gene(s). In vivo validation was performed in C57BL/6 mice with unilateral ureteral obstruction (UUO). In vitro validation was performed in rat kidney fibroblast NRK-49F cells. Mimics and inhibitors of miR-29c-3p were constructed. The target gene Fer was monitored by RT-PCR and western blotting. The levels of interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α in serum and media were measured by ELISA. Results The Fer expression and protein level were gradually increased during 14 days of UUO modeling. miR-29c-3p expression was strongly correlated with that of Fer. In vivo validation showed increased expressions of fibrosis-associated genes and increased phospoho-Smad3 level in the UUO model. Fer-knockdown (KD) significantly decreased expressions of fibrosis-associated genes. Pharmaceutical inhibition of Fer showed similar effects to miR-29c-3p, and miR inhibition showed a significant decrease of excretion of inflammatory factors. Conclusion Dysregulation of miR-29c-3p and Fer plays a role in RF. Pharmaceutical or genetic inhibition of Fer may serve as the potential treatment for RF.


2021 ◽  
Vol 12 ◽  
Author(s):  
Haofeng Zheng ◽  
Yannan Zhang ◽  
Jiannan He ◽  
Zhe Yang ◽  
Rui Zhang ◽  
...  

Chronic kidney disease (CKD), which is associated with high morbidity, remains a worldwide health concern, while effective therapies remain limited. Hydroxychloroquine (HCQ), which mainly targets toll-like receptor-7 (TLR-7) and TLR-9, is associated with a lower risk of incident CKD. Taking into account that TLR-9 is involved in the development of renal fibrosis and serves as a potential therapy target for CKD, we investigated whether HCQ could attenuate CKD via TLR-9 signal pathway. The effects of HCQ on renal tubulointerstitial fibrosis were further explored using a mouse model of renal tubulointerstitial fibrosis after ischemia/reperfusion injury. Bone marrow-derived macrophages were isolated to explore the effects of HCQ in vitro. Judicious use of HCQ efficiently inhibited the activation of macrophages and MAPK signaling pathways, thereby attenuating renal fibrosis in vivo. In an in vitro model, results showed that HCQ promoted apoptosis of macrophages and inhibited activation of macrophages, especially M2 macrophages, in a dose-dependent manner. Because TLR-7 is not involved in the development of CKD post-injury, a TLR-9 knockout mouse was used to explore the mechanisms of HCQ. The effects of HCQ on renal fibrosis and macrophages decreased after depletion of TLR-9 in vivo and in vitro. Taken together, this study indicated that proper use of HCQ could be a new strategy for anti-fibrotic therapy and that TLR-9 could be a potential therapeutic target for CKD following acute kidney injury.


2020 ◽  
Author(s):  
Mi-Gyoeng Gwon ◽  
Hyun-Jin An ◽  
Hyemin Gu ◽  
Young-Ah Kim ◽  
Sang Mi Han ◽  
...  

Abstract Background Renal fibrosis is a progressive and chronic process that influences kidneys with chronic kidney disease (CKD), irrespective of cause, leading to irreversible failure of renal function and end-stage kidney disease. Among the signaling related to renal fibrosis, transforming growth factor-β1 (TGF-β1) signaling is a major pathway that induces the activation of myofibroblasts and the production of extracellular matrix (ECM) molecules. Apamin, a component of bee venom (BV), has been studied in relation to various diseases. However, the effect of apamin on renal interstitial fibrosis has not been investigated. The aim of this study was to estimate the beneficial effect of apamin in unilateral ureteral obstruction (UUO)-induced renal fibrosis and TGF-β1-induced renal fibroblast activation.Results This study revealed that obstructive kidney injury induced an inflammatory response, tubular atrophy, and ECM accumulation. However, apamin treatment suppressed the increased expression of fibrotic-related genes, including α-SMA, vimentin, and fibronectin. Administration of apamin also attenuated the renal tubular cells injury and tubular atrophy. In addition, apamin attenuated fibroblast activation, ECM synthesis, and inflammatory cytokines such as TNF-α, IL-1β and IL-6 by suppressing the TGF-β1-canonical and non-canonical signaling pathways.Conclusions This study shown that apamin inhibites UUO-induced renal fibrosis in vivo and TGF-β1-induced renal fibroblasts activation in vitro. Apamin inhibited the inflammatory response, tubular atrophy, ECM accumulation, fibroblast activation, and renal interstitial fibrosis through suppression of TGF-β1/Smad2/3 and STAT3 signaling pathways. These results suggest that apamin might be a potential therapeutic agent for renal fibrosis.


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