Serum Lysyl Oxidase Is a Potential Diagnostic Biomarker for Kidney Fibrosis

2020 ◽  
Vol 51 (11) ◽  
pp. 907-918
Author(s):  
Xiao-qin Zhang ◽  
Xin Li ◽  
Wen-qian Zhou ◽  
Xi Liu ◽  
Jie-li Huang ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Interstitial Fibrosis ◽  
Lysyl Oxidase ◽  
Characteristic Curve ◽  
Area Under The Curve ◽  
Renal Tissue ◽  
Diagnostic Biomarker ◽  
Kidney Fibrosis

<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.

scholarly journals Neural transcription factor Pou4f1 promotes renal fibrosis via macrophage–myofibroblast transition

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 ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Renal Fibrosis ◽  
Interstitial Fibrosis ◽  
Early Stage ◽  
Transcriptional Level ◽  
Pou Domain ◽  
Renal Fibrogenesis ◽  
Tgf Β1

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.

scholarly journals Biomarkers of Chronic Renal Tubulointerstitial Injury

2019 ◽  
Vol 67 (9) ◽  
pp. 633-641 ◽  
Author(s):  
Serena M. Bagnasco ◽  
Avi Z. Rosenberg
Keyword(s):  
Interstitial Fibrosis ◽  
Renal Tissue ◽  
Experimental Models ◽  
Renal Outcome ◽  
Tubulointerstitial Injury ◽  
Tubular Atrophy ◽  
Non Invasive ◽  
Diagnosis And Prognosis

Progression of renal parenchyma injury is characterized by increasing interstitial fibrosis and tubular atrophy, irrespective of the cause. Histopathologic assessment of renal tissue obtained by biopsy remains the gold standard for determining the presence and extent of tubulointerstitial scarring. Discovery of robust non-invasive means for capturing a snapshot and for longitudinal monitoring of parenchymal deterioration has been the focus of intense multimodal effort by investigators within the renal community and beyond. Research in this field has included the use of in vitro and in vivo experimental models and has fostered the development and evaluation of tissue and biofluid assays for novel analytes with potential translation to the diagnosis and prognosis of kidney disease. Here, we examine recent advances in the search of “biomarkers” for detection of renal tubulointerstitial scarring and prediction of renal outcome in human renal disease.

scholarly journals Pharmacological and genetic depletion of fibrinogen protects from kidney fibrosis

2014 ◽  
Vol 307 (4) ◽  
pp. F471-F484 ◽  
Author(s):  
Florin L. Craciun ◽  
Amrendra K. Ajay ◽  
Dana Hoffmann ◽  
Janani Saikumar ◽  
Steven L. Fabian ◽  
...  
Keyword(s):  
Transforming Growth Factor ◽  
Interstitial Fibrosis ◽  
Wild Type ◽  
Tubular Atrophy ◽  
Kidney Fibrosis ◽  
Surface Receptors ◽  
Fibrotic Disorders ◽  
Vehicle Treated Control

Fibrinogen (Fg) has been implicated in the pathogenesis of several fibrotic disorders by acting as a profibrotic ligand for a variety of cellular surface receptors and by modulating the provisional fibrin matrix formed after injury. We demonstrated increased renal Fg expression after unilateral ureteral obstruction and folic acid (FA) nephropathy in mice, respectively. Urinary Fg excretion was also increased in FA nephropathy. Using in vitro and in vivo approaches, our results suggested that IL-6 mediates STAT3 activation in kidney fibrosis and that phosphorylated (p)STAT3 binds to Fgα, Fgβ, and Fgγ promoters in the kidney to regulate their transcription. Genetically modified Fg heterozygous mice (∼75% of normal plasma Fg levels) exhibited only 3% kidney interstitial fibrosis and tubular atrophy after FA nephropathy compared with 24% for wild-type mice. Fibrinogenolysis through Ancrod administration after FA reduced interstitial fibrosis more than threefold compared with vehicle-treated control mice. Mechanistically, we show that Fg acts synergistically with transforming growth factor (TGF)-β1 to induce fibroblast proliferation and activates TGF-β1/pSMAD2 signaling. This study offers increased understanding of Fg expression and molecular interactions with TGF-β1 in the progression to kidney fibrosis and, importantly, indicates that fibrinogenolytics like Ancrod present a treatment opportunity for a yet intractable disease.

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
Keyword(s):  
Renal Fibrosis ◽  
Interstitial Fibrosis ◽  
Lysyl Oxidase ◽  
Rat Kidney ◽  
Ischemia Reperfusion ◽  
Mek Inhibitor ◽  
Collagen Crosslinking ◽  
Fibrosis Progression

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.

Apamin inhibits renal interstitial inflammation and fibrosis via suppressing TGF-β1 and STAT3 signaling pathway in vivo and in vitro

2020 ◽  
Author(s):  
Mi-Gyoeng Gwon ◽  
Hyun-Jin An ◽  
Hyemin Gu ◽  
Young-Ah Kim ◽  
Sang Mi Han ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Renal Fibrosis ◽  
Interstitial Fibrosis ◽  
Renal Interstitial Fibrosis ◽  
Tubular Atrophy ◽  
Fibroblast Activation ◽  
Stat3 Signaling ◽  
Tgf Β1

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.

scholarly journals Involvement of FATP2-mediated tubular lipid metabolic reprogramming in renal fibrogenesis

2020 ◽  
Vol 11 (11) ◽  
Author(s):  
Yuting Chen ◽  
Qi Yan ◽  
Mengyue Lv ◽  
Kaixin Song ◽  
Yue Dai ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Lipid Metabolism ◽  
Growth Factor ◽  
Renal Fibrosis ◽  
Interstitial Fibrosis ◽  
Tissue Growth ◽  
Metabolic Reprogramming ◽  
Kidney Fibrosis

AbstractFollowing a chronic insult, renal tubular epithelial cells (TECs) contribute to the development of kidney fibrosis through dysregulated lipid metabolism that lead to lipid accumulation and lipotoxicity. Intracellular lipid metabolism is tightly controlled by fatty acids (FAs) uptake, oxidation, lipogenesis, and lipolysis. Although it is widely accepted that impaired fatty acids oxidation (FAO) play a crucial role in renal fibrosis progression, other lipid metabolic pathways, especially FAs uptake, has not been investigated in fibrotic kidney. In this study, we aim to explore the potential mechanically role of FAs transporter in the pathogenesis of renal fibrosis. In the present study, the unbiased gene expression studies showed that fatty acid transporter 2 (FATP2) was one of the predominant expressed FAs transport in TECs and its expression was tightly associated with the decline of renal function. Treatment of unilateral ureteral obstruction (UUO) kidneys and TGF-β induced TECs with FATP2 inhibitor (FATP2i) lipofermata restored the FAO activities and alleviated fibrotic responses both in vivo and in vitro. Moreover, the expression of profibrotic cytokines including TGF-β, connective tissue growth factor (CTGF), fibroblast growth factor (FGF), and platelet-derived growth factor subunit B (PDGFB) were all decreased in FATP2i-treated UUO kidneys. Mechanically, FATP2i can effectively attenuate cell apoptosis and endoplasmic reticulum (ER) stress induced by TGF-β treatment in cultured TECs. Taking together, these findings reveal that FATP2 elicits a profibrotic response to renal interstitial fibrosis by inducing lipid metabolic reprogramming including abnormal FAs uptake and defective FAO in TECs.

scholarly journals In Vitro and In Vivo Antifibrotic Effects of Fraxetin on Renal Interstitial Fibrosis via the ERK Signaling Pathway

Toxins ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 474
Author(s):  
Yi-Hsien Hsieh ◽  
Tung-Wei Hung ◽  
Yong-Syuan Chen ◽  
Yi-Ning Huang ◽  
Hui-Ling Chiou ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Renal Fibrosis ◽  
Interstitial Fibrosis ◽  
Renal Tissue ◽  
Collagen Iv ◽  
Cytotoxic Effects ◽  
Anti Oxidant ◽  
Natural Derivative

Fraxetin, a natural derivative of coumarin, is known to have anti-inflammatory, anti-oxidant, and hepatoprotective effects in multiple diseases and in liver fibrosis. Whether fraxetin exerts similar effects against renal fibrosis is unknown. In a Unilateral Ureteral Obstruction (UUO) mouse model of renal fibrosis, fraxetin decreased UUO-induced renal dysfunction with a marked reduction in renal interstitial collagen fibers as detected by Masson’s Trichrome staining. Fraxetin treatment also inhibited the expression of α-SMA, Collagen I, Collagen IV, fibronectin, N-cadherin, vimentin, phosphorylated-ERK, and increased the expression of E-cadherin in UUO mice, as shown by immunohistochemical staining and western blot analysis. In vitro studies showed that fraxetin and indoxyl sulfate had no cytotoxic effects on MES13 kidney cells, but that fraxetin significantly decreased IS-induced cell motility and decreased protein expression of α-SMA, N-cadherin, vimentin, and Collagen IV via the ERK-mediated signaling pathway. These findings provide insight into the mechanism underlying fraxetin-induced inhibition of fibrogenesis in renal tissue and suggest that fraxetin treatment may be beneficial for slowing CKD progression.

scholarly journals Molecular Mechanistic Pathways Targeted by Natural Antioxidants in the Prevention and Treatment of Chronic Kidney Disease

Antioxidants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 15
Author(s):  
Mohamed Mohany ◽  
Mohammed M. Ahmed ◽  
Salim S. Al-Rejaie
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Transforming Growth Factor Beta ◽  
Clinical Studies ◽  
Transforming Growth Factor ◽  
Related Factor ◽  
Nuclear Factor ◽  
Kidney Fibrosis

Chronic kidney disease (CKD) is the progressive loss of renal function and the leading cause of end-stage renal disease (ESRD). Despite optimal therapy, many patients progress to ESRD and require dialysis or transplantation. The pathogenesis of CKD involves inflammation, kidney fibrosis, and blunted renal cellular antioxidant capacity. In this review, we have focused on in vitro and in vivo experimental and clinical studies undertaken to investigate the mechanistic pathways by which these compounds exert their effects against the progression of CKD, particularly diabetic nephropathy and kidney fibrosis. The accumulated and collected data from preclinical and clinical studies revealed that these plants/bioactive compounds could activate autophagy, increase mitochondrial bioenergetics and prevent mitochondrial dysfunction, act as modulators of signaling pathways involved in inflammation, oxidative stress, and renal fibrosis. The main pathways targeted by these compounds include the canonical nuclear factor kappa B (NF-κB), canonical transforming growth factor-beta (TGF-β), autophagy, and Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid factor 2-related factor 2 (Nrf2)/antioxidant response element (ARE). This review presented an updated overview of the potential benefits of these antioxidants and new strategies to treat or reduce CKD progression, although the limitations related to the traditional formulation, lack of standardization, side effects, and safety.

Three-dimensional Growth of Renal Epithelial Cells in Vitro: A Tool in Toxicity Testing

1993 ◽  
Vol 21 (2) ◽  
pp. 191-195 ◽  
Author(s):  
Knut-Jan Andersen ◽  
Erik Ilsø Christensen ◽  
Hogne Vik
Keyword(s):  
Epithelial Cells ◽  
Three Dimensional ◽  
Toxicity Testing ◽  
Renal Tissue ◽  
Epithelial Cell Line ◽  
Multicellular Spheroids ◽  
Renal Epithelial Cell ◽  
Renal Epithelial Cells

The tissue culture of multicellular spheroids from the renal epithelial cell line LLC-PK1 (proximal tubule) is described. This represents a biological system of intermediate complexity between renal tissue in vivo and simple monolayer cultures. The multicellular structures, which show many similarities to kidney tubules in vivo, including a vectorial water transport, should prove useful for studying the potential nephrotoxicity of drugs and chemicals in vitro. In addition, the propagation of renal epithelial cells as multicellular spheroids in serum-free culture may provide information on the release of specific biological parameters, which may be suppressed or masked in serum-supplemented media.

Homeobox-A13 acts as a functional prognostic and diagnostic biomarker via regulating P53 and Wnt signaling pathways in lung cancer

2021 ◽  
pp. 1-16
Author(s):  
Yang Wang ◽  
Bo He ◽  
Yan Dong ◽  
Gong-Jin He ◽  
Xiao-Wei Qi ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Signaling Pathways ◽  
Cox Regression ◽  
Prognostic Significance ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Clinical Feature ◽  
Diagnostic Biomarker

BACKGROUND: The prognosis of lung cancer patients is poor without useful prognostic and diagnostic biomarker. To search for novel prognostic and diagnostic markers, we previously found homeobox-A13 (HOXA13) as a promising candidate in lung cancer. OBJECTIVE: To determine the precisely clinical feature, prognostic and diagnostic value, possible role and mechanism of HOXA13. METHODS: Gene-expression was explored by real-time quantitative-PCR, western-blot and tissue-microarray. The associations were analyzed by Chi-square test, Kaplan-Meier and Cox-regression. The roles and mechanisms were evaluated by MTS, EdU, transwell, xenograft tumor and luciferase-reporter assays. RESULTS: HOXA13 expression is increased in tumors, and correlated with age of patients. HOXA13 expression is associated with unfavorable overall survival and relapse-free survival of patients in four cohorts. Interestingly, HOXA13 has different prognostic significance in adenocarcinoma (ADC) and squamous-cell carcinoma (SCC), and is a sex- and smoke-related prognostic factor only in ADC. Importantly, HOXA13 can serve as a diagnostic biomarker for lung cancer, especially for SCC. HOXA13 can promote cancer-cell proliferation, migration and invasion in vitro, and facilitate tumorigenicity and tumor metastasis in vivo. HOXA13 acts the oncogenic roles on tumor growth and metastasis by regulating P53 and Wnt/β-catenin signaling activities in lung cancer. CONCLUSIONS: HOXA13 is a new prognostic and diagnostic biomarker associated with P53 and Wnt/β-catenin signaling pathways.

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