PAX2 may induce ADAM10 expression in renal tubular epithelial cells and contribute to epithelial-to-mesenchymal transition

Evaluation of Cisplatin-Induced Acute Renal Failure Amelioration Using Fondaparinux and Alteplase

Acute renal failure (ARF) is a deleterious condition with increased mortality or healthcare costs or dialysis-dependent end-stage renal disease. The study aims to compare prophylaxis with fondaparinux (Fund) vs. treatment with alteplase (Alt) in ameliorating cisplatin (Cis)-induced ARF. Sixty male mice were equally divided randomly into six groups of control, Cis, Alt, and Cis + Alt groups receiving normal saline for 10 days. All four groups except for the control received Cis (30 mg/kg, i.p.) on day 7, and 6 h later, both the Alt groups received Alt (0.9 mg/kg, i.v.). The animal groups Fund and Fund + Cis received Fund (5 mg/kg, i.p.) for 10 days, and the Fund + Cis group on day 7 received Cis. All the animal groups were euthanized 72 h after the Cis dose. The Fund + Cis group showed significantly increased expression levels of platelet count, retinoid X receptor alpha (RXR-α) and phosphorylated Akt (p-Akt) in addition to decreased levels of urea, blood urea nitrogen (BUN), uric acid, white blood cells (WBCs), red blood cells (RBCs), relative kidney body weight, kidney injury score, glucose, prothrombin (PT), A Disintegrin And Metalloproteinases-10 (ADAM10), extracellular matrix deposition, protease-activated receptor 2 (PAR-2), and fibrinogen expression when compared to the Cis-only group. Meanwhile, the Cis + Alt group showed increased caspase-3 expression in addition to decreased levels of urea, BUN, uric acid, WBCs, RBCs, glucose, platelet count and PT expression with a marked decrease in PAR-2 protein expression compared to the Cis group. The creatinine levels for both the Fund + Cis and Cis + Alt groups were found to be comparable to those of the Cis-only group. The results demonstrate that the coagulation system's activation through the stimulation of PAR-2 and fibrinogen due to Cis-induced ADAM10 protein expression mediated the apoptotic pathway, as indicated by caspase-3 expression through the p-Akt pathway. This is normally accompanied by the loss of RXR-α distal and proximal tubules as lipid droplets. When the animals were pre-treated with the anticoagulant, Fund, the previous deleterious effect was halted while the fibrinolytic agent, Alt, most of the time failed to treat Cis-induced toxicity.

ADAM10 and ADAM17, Major Regulators of Chronic Kidney Disease Induced Atherosclerosis?

Chronic kidney disease (CKD) is a major health problem, affecting millions of people worldwide, in particular hypertensive and diabetic patients. CKD patients suffer from significantly increased cardiovascular disease (CVD) morbidity and mortality, mainly due to accelerated atherosclerosis development. Indeed, CKD not only affects the kidneys, in which injury and maladaptive repair processes lead to local inflammation and fibrosis, but also causes systemic inflammation and altered mineral bone metabolism leading to vascular dysfunction, calcification, and thus, accelerated atherosclerosis. Although CKD and CVD individually have been extensively studied, relatively little research has studied the link between both diseases. This narrative review focuses on the role of a disintegrin and metalloproteases (ADAM) 10 and ADAM17 in CKD and CVD and will for the first time shed light on their role in CKD-induced CVD. By cleaving cell surface molecules, these enzymes regulate not only cellular sensitivity to their micro-environment (in case of receptor cleavage), but also release soluble ectodomains that can exert agonistic or antagonistic functions, both locally and systemically. Although the cell-specific roles of ADAM10 and ADAM17 in CVD, and to a lesser extent in CKD, have been explored, their impact on CKD-induced CVD is likely, yet remains to be elucidated.

Comprehensive analyses of the microRNA-messenger RNA-transcription factor regulatory network in mouse and human renal fibrosis

Objective: The aim of this study was to construct a microRNA (miRNA)-messenger RNA (mRNA)-transcription factor (TF) regulatory network and explore underlying molecular mechanisms, effective biomarkers, and drugs in renal fibrosis (RF). Methods: A total of six datasets were downloaded from Gene Expression Omnibus. "Limma" and "DESeq2" packages in R software and GEO2R were applied to identify the differentially expressed miRNAs and mRNAs (DEmiRNAs and DEmRNAs, respectively). The determination and verification of DEmiRNAs and DEmRNAs were performed through the integrated analysis of datasets from five mouse 7 days of unilateral ureteral obstruction datasets and one human chronic kidney disease dataset and the Human Protein Atlas (http://www.proteinatlas.org). Target mRNAs of DEmiRNAs and TFs were predicted by prediction databases and the iRegulon plugin in Cytoscape, respectively. A protein-protein interaction network was constructed using STRING, Cytoscape v3.9.1, and CytoNCA. Functional enrichment analysis was performed by DIANA-miRPath v3.0 and R package "clusterProfiler." A miRNA-mRNA-TF network was established using Cytoscape. Receiver operating characteristic (ROC) curve analysis was used to examine the diagnostic value of the key hub genes. Finally, the Comparative Toxicogenomics Database and Drug-Gene Interaction database were applied to identify potential drugs. Results: Here, 4 DEmiRNAs and 11 hub genes were determined and confirmed in five mouse datasets, of which Bckdha and Vegfa were further verified in one human dataset and HPA, respectively. Moreover, Bckdha and Vegfa were also predicted by miR-125a-3p and miR-199a-5p, respectively, in humans as in mice. The sequences of miR-125a-3p and miR-199a-5p in mice were identical to those in humans. A total of 6 TFs were predicted to regulate Bckdha and Vegfa across mice and humans; then, a miRNA-mRNA-TF regulatory network was built. Subsequently, ROC curve analysis showed that the area under the curve value of Vegfa was 0.825 (p = 0.002). Finally, enalapril was identified to target Vegfa for RF therapy. Conclusion: Pax2, Pax5, Sp1, Sp2, Sp3, and Sp4 together with Bckdha-dependent miR-125a-3p/Vegfa-dependent miR-199a-5p formed a co-regulatory network enabling Bckdha/Vegfa to be tightly controlled in the underlying pathogenesis of RF across mice and humans. Vegfa could act as a potential novel diagnostic marker and might be targeted by enalapril for RF therapy.

Ectodomain shedding by ADAM proteases as a central regulator in kidney physiology and disease

Besides its involvement in blood and bone physiology, the kidney's main function is to filter substances and thereby regulate the electrolyte composition of body fluids, acid-base balance and toxin removal. Depending on underlying conditions, the nephron must undergo remodeling and cellular adaptations. The proteolytic removal of cell surface proteins via ectodomain shedding by A Disintegrin and Metalloproteases (ADAMs) is of importance for the regulation of cell-cell and cell-matrix adhesion of renal cells. ADAM10 controls glomerular and tubule development in a Notch1 signaling-dependent manner and regulates brush border composition. ADAM17 regulates the renin angiotensin system and is together with ADAM10 involved in calcium phosphate homeostasis. In kidney disease ADAMs, especially ADAM17 contribute to inflammation through their involvement in IL-6 trans-signaling, Notch-, epithelial growth factor receptor-, and tumor necrosis factor α signaling. ADAMs are interesting drug targets to reduce the inflammatory burden, defective cell adhesion and impaired signaling pathways in kidney diseases.

ADAMs family in kidney physiology and pathology

A disintegrin and metalloproteinases (ADAMs) family are proteolytic transmembrane proteases that modulate diverse cell functions and coordinate intercellular communication. ADAMs are responsible for regulating cell proliferation, differentiation, migration, and organ morphogenesis in kidney development. Abnormally activated ADAMs drive inflammation and fibrosis in response to kidney diseases such as acute kidney injury, diabetic kidney disease, polycystic kidney disease, and chronic allograft nephropathy. ADAM10 and ADAM17, known as the most characterized members of ADAMs, are extensively investigated in kidney diseases. Notably, ADAM proteases have the potential to be targets for developing novel treatment approaches in kidney diseases.

Dasatinib mitigates renal fibrosis in a rat model of UUO via inhibition of Src/STAT-3/NF-κB signaling

This research aimed to investigate the reno-protective impact of the tyrosine kinase inhibitor dasatinib (DAS) against renal fibrosis induced by unilateral ureteral obstruction (UUO) in rats. DAS administration improved renal function and mitigated renal oxidative stress with paralleled reduction in the ligated kidney mass index, significant retraction in renal histopathological alterations and suppression of renal interstitial fibrosis. Nevertheless, DAS administration attenuated renal expression of phosphorylated Src (p-Src), Abelson (c-Abl) tyrosine kinases, nuclear factor-kappaB (NF-κB) p65, and phosphorylated signal transducer and activator of transcription-3 (p-STAT-3)/STAT-3 with paralleled reduction in renal contents of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and monocyte chemoattractant protein-1 (MCP-1). DAS diminished interstitial macrophage infiltration and decreased renal profibrotic transforming growth factor-β1 (TGF-β1) levels and suppressed interstitial expression of renal α-smooth muscle actin (α-SMA) and fibronectin. Collectively, DAS slowed the progression of renal interstitial fibrosis, possibly via attenuating renal oxidative stress, impairing Src/STAT-3/NF-κB signaling, and reducing renal inflammation.

Nifuroxazide suppresses UUO-induced renal fibrosis in rats via inhibiting STAT-3/NF-κB signaling, oxidative stress and inflammation

The current work explored the influences of nifuroxazide, an in vivo inhibitor of signal transducer and activator of transcription-3 (STAT-3) activation, on tubulointerstitial fibrosis in rats with obstructive nephropathy using unilateral ureteral obstruction (UUO) model. Thirty-two male Sprague Dawley rats were assigned into 4 groups (n = 8/group) at random. Sham and UUO groups were orally administered 0.5% carboxymethyl cellulose (CMC) (2.5 mL/kg/day), while Sham-NIF and UUO-NIF groups were treated with 20 mg/kg/day of NIF (suspended in 0.5% CMC, orally). NIF or vehicle treatments were started 2 weeks after surgery and continued for further 2 weeks. NIF treatment ameliorated kidney function in UUO rats, where it restored serum creatinine, blood urea, serum uric acid and urinary protein and albumin to near-normal levels. NIF also markedly reduced histopathological changes in tubules and glomeruli and attenuated interstitial fibrosis in UUO-ligated kidneys. Mechanistically, NIF markedly attenuated renal immunoexpression of E-cadherin and α-smooth muscle actin (α-SMA), diminished renal oxidative stress (↓ malondialdehyde (MDA) levels and ↑ superoxide dismutase (SOD) activity), lessened renal protein expression of phosphorylated-STAT3 (p-STAT-3), phosphorylated-Src (p-Src) kinase, the Abelson tyrosine kinase (c-Abl) and phosphorylated nuclear factor-kappaB p65 (pNF-κB p65), decreased renal cytokine levels of transforming growth factor-β1 (TGF-β1), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and monocyte chemoattractant protein-1 (MCP-1) and reduced number of cluster of differentiation 68 (CD68) immunolabeled macrophages in UUO renal tissues, compared to levels in untreated UUO kidneys. Taken together, NIF treatment suppressed interstitial fibrosis in UUO renal tissues, probably via inhibiting STAT-3/NF-κB signaling and attenuating renal oxidative stress and inflammation.

ADAM10 mediates ectopic proximal tubule development and renal fibrosis through Notch signalling

Disturbed intrauterine development increases the risk of renal disease. Various studies have reported that Notch signalling plays a significant role in kidney development and kidney diseases. A disintegrin and metalloproteinase domain 10 (ADAM10), an upstream protease of the Notch pathway, is also reportedly involved in renal fibrosis. However, how ADAM10 interacts with the Notch pathway and causes renal fibrosis is not fully understood. In this study, using a prenatal chlorpyrifos (CPF) exposure mouse model, we investigated the role of the ADAM10/Notch axis in kidney development and fibrosis. We found that prenatal CPF‐exposure mice presented overexpression of Adam10, Notch1 and Notch2, and led to premature depletion of Six2⁺ nephron progenitors and ectopic formation of proximal tubules (PTs) in the embryonic kidney. These abnormal phenotypic changes persisted in mature kidneys due to the continuous activation of ADAM10/Notch and showed aggravated renal fibrosis in adults. Finally, both ADAM10 and NOTCH2 expression were positively correlated with the degree of renal interstitial fibrosis in IgA nephropathy patients, and increased ADAM10 expression was negatively correlated with decreased kidney function evaluated by serum creatinine, cystatin C, and estimated glomerular filtration rate. Regression analysis also indicated that ADAM10 expression was an independent risk factor for fibrosis in IgAN. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

Lefty-1 inhibits renal epithelial-mesenchymal transition by antagonizing the TGF-β/Smad signaling pathway

Epithelial-mesenchymal transition (EMT) is a biological process in which tubular epithelial cells lose their phenotypes, and new mesenchymal feature are obtained. In particular, type II EMT possibly contributes to renal tissue fibrogenesis. Recent studies indicate that Lefty-1, a novel member of the TGF-β superfamily with pleiotropical and biological regulation characteristics on TGF-β and other signaling pathways, is considered to have potential fibrotic effects. However, its role in EMT, which is often a long-term consequence of renal tubulointerstitial fibrosis, remains unknown. In this study, we found that Lefty-1 alleviates EMT induction through antagonizing TGF-β/Smad pathway in vivo and in vitro. In unilateral ureteral obstruction (UUO) model mice, administration of adenovirus-mediated overexpression of Lefty-1 (Ad-Lefty-1) significantly reduced TGF-β1/Smad expression and alleviated the phenotypic transition of epithelial cells to mesenchymal cells and extracellular matrix (ECM) accumulation. In high glucose-induced rat renal tubular duct epithelial cell line (NRK-52E), EMT and ECM synthesis were alleviated with Lefty-1 treatment, which significantly inhibited TGF-β1/Smad pathway activation in UUO mice and high glucose-treated NRK-52E cells. Thus, Lefty-1 can alleviate EMT and renal interstitial fibrosis in vivo and in vitro through antagonizing the TGF-β/Smad pathway, and Lefty-1 might have a potential novel therapeutic effect on fibrotic kidney diseases.

MiR-449a regulates the cell migration and invasion of human non-small cell lung carcinoma by targeting ADAM10

Background: MicroRNAs (miRNAs) are non-coding small RNAs that have been shown to play a key role in the development of many tumors. However, its specific mechanism of action in non-small cell lung cancer (NSCLC) is not very clear. Purpose: This study was to identify the effect of miRNA-449a on NSCLC invasion and migration. Methods: We used quantitative real-time PCR experiments to demonstrate that miRNA-449a is down-regulated in NSCLC tissues and cell lines. We also used the Transwell assay to detect cell invasion and migration, and the Western Blot assay  was used to detect protein expression. The dual luciferase assay was used to detect the targeting relationship between miR-449a and A Disintegrin And Metalloproteinases 10 (ADAM10). Results: Our experiments demonstrated that miRNA-449a was down-regulated in NSCLC tissues and cell lines. When miRNA-449a was up-regulated in NSCLC cells, the invasion and migration ability of the cells was weakened, and the expression of ADAM10 was decreased. After down-regulation of miRNA-449a, the cell's invasion and migration ability was enhanced, and the expression of ADAM10 was increased. Through dual luciferase assays, we also found that miRNA-449a can target ADAM10 to delay the progression of epithelial-mesenchymal transition (EMT) and inhibit invasion and migration. Conclusion: Our experiments demonstrated that miRNA-449a acted as a tumor suppressor gene through inhibiting the expression of ADAM10 in NSCLC.

The role of extracellular vesicles in renal fibrosis

As a particularly important mediator of intercellular communication, extracellular vesicles (EVs) have been proved to be extensively involved in various system diseases over the past two decades, including in renal diseases. As is well-known, renal fibrosis is the common pathological process of any ongoing renal disease or adaptive repair of kidney injury based on current knowledge. Although much work has been performed focusing on EVs in various renal diseases, the role of EVs in renal fibrosis has not been described in detail and summarized. In this review, we provide a brief overview of the definition, classification and biological process of EVs. Then, the potential mechanisms of EVs in renal fibrosis are illustrated. Lastly, recent advances in EVs and the implications of EVs for diagnosis and therapy in renal fibrosis disease are introduced. We look forward to a more comprehensive understanding of EVs in renal fibrosis, which could be a boon to patients with renal fibrosis disease.