MMP-1 and -3 haplotype is associated with congenital anomalies of the kidney and urinary tract

New Derivatives of N-Hydroxybutanamide: Preparation, MMP Inhibition, Cytotoxicity, and Antitumor Activity

Using a novel method of N-substituted succinimide ring opening, new N-hydroxybutanamide derivatives were synthesized. These compounds were evaluated for their ability to inhibit matrix metalloproteinases (MMPs) and their cytotoxicity. The iodoaniline derivative of N1-hydroxy-N4-phenylbutanediamide showed the inhibition of MMP-2, MMP-9, and MMP-14 with an IC50 of 1-1.5 μM. All the compounds exhibited low toxicity towards carcinoma cell lines HeLa and HepG2. The iodoaniline derivative was also slightly toxic to glioma cell lines A-172 and U-251 MG. Non-cancerous FetMSC and Vero cells were found to be the least sensitive to all the compounds. In vivo studies demonstrated that the iodoaniline derivative of N1-hydroxy-N4-phenylbutanediamide had low acute toxicity. In a mouse model of B16 melanoma, this compound showed both antitumor and antimetastatic effects, with a 61.5% inhibition of tumor growth and an 88.6% inhibition of metastasis. Our findings suggest that the iodoaniline derivative of N1-hydroxy-N4-phenylbutanediamide has potential as a lead structure for the development of new MMP inhibitors. Our new synthetic approach can be a cost-effective method for the synthesis of inhibitors of metalloenzymes with promising antitumor potential.

Downregulation of fibrosis related hsa-miR-29c-3p in human CAKUT

Congenital anomalies of the kidney and urinary tract (CAKUT) represent structural and functional urinary system malformations and take place as one of the most common congenital malformations with an incidence of 1:500. Ureteral obstruction-induced hydronephrosis is associated with renal fibrosis and chronic kidney diseases in the pediatric CAKUT. We aimed to construct interaction network of previously bioinformatically associated miRNAs with CAKUT differentially expressed genes in order to prioritize those associated with fibrotic process and to experimentally validate the expression of selected miRNAs in CAKUT patients compared to control group. We constructed interaction network of hsa-miR-101-3p, hsa-miR-101-5p and hsa-miR-29c-3p that showed significant association with fibrosis. The top enriched molecular pathway was extracellular matrix-receptor interaction (adjusted p = .0000263). We experimentally confirmed expression of three miRNAs (hsa-miR-29c-3p, hsa-miR-101-3p and hsa-miR-101-5p) in obstructed ureters (ureteropelvic junction obstruction and primary obstructive megaureter) and vesicoureteral reflux. The hsa-miR-29c-3p was shown to have lower expression in both patient groups compared to controls. Relative levels of hsa-miR-101-5p and hsa-miR-101-3p showed significant positive correlations in both groups of patients. Statistically significant correlation was observed between hsa-miR-101 (-3p and -5p) and hsa-miR-29c-3p only in the obstructed group. The significant downregulation of anti-fibrotic hsa-miR-29c-3p in obstructive CAKUT could explain activation of genes involved in fibrotic processes. As miRNAs are promising candidates in therapeutic approaches our results need further measurement of fibrotic markers or assessment of extent of fibrosis and functional evaluation of hsa-miR-29c.

Matrix Metalloproteinase-10 in Kidney Injury Repair and Disease

Matrix metalloproteinase-10 (MMP-10) is a zinc-dependent endopeptidase with the ability to degrade a broad spectrum of extracellular matrices and other protein substrates. The expression of MMP-10 is induced in acute kidney injury (AKI) and chronic kidney disease (CKD), as well as in renal cell carcinoma (RCC). During the different stages of kidney injury, MMP-10 may exert distinct functions by cleaving various bioactive substrates including heparin-binding epidermal growth factor (HB-EGF), zonula occludens-1 (ZO-1), and pro-MMP-1, -7, -8, -9, -10, -13. Functionally, MMP-10 is reno-protective in AKI by promoting HB-EGF-mediated tubular repair and regeneration, whereas it aggravates podocyte dysfunction and proteinuria by disrupting glomerular filtration integrity via degrading ZO-1. MMP-10 is also involved in cancerous invasion and emerges as a promising therapeutic target in patients with RCC. As a secreted protein, MMP-10 could be detected in the circulation and presents an inverse correlation with renal function. Due to the structural similarities between MMP-10 and the other MMPs, development of specific inhibitors targeting MMP-10 is challenging. In this review, we summarize our current understanding of the role of MMP-10 in kidney diseases and discuss the potential mechanisms of its actions.

Posterior urethral valve in fetuses: evidence for the role of inflammatory molecules

BACKGROUND

The aim of this cross-sectional study was to investigate inflammatory biomarkers in urine samples of 24 fetuses with posterior urethral valve (PUV) collected at 22 ± 4 weeks of gestation and to compare the findings with measurements in urine samples of 22 male healthy preterm neonates at 23 ± 4 weeks (control group).

METHODS

Inflammatory biomarkers in urine were measured using a cytometric bead array [interleukin (IL)-2, IL-4, IL-6, IL-10, interferon (IFN)-γ, soluable tumor necrosis factor receptor (TNFR) 1, sTNFR2, monocyte chemoattractant protein-1/chemokine ligand 2 (MCP-1/CCL2), eotaxin/CCL11 and interferon gamma-induced protein/10/C-X-C motif chemokine 10 (IP-10/CXCL10)] and ELISA assays [TNF, IL-8/CXCL8 and transforming growth factor-beta (TGF-β)]. The Mann-Whitney test was used to compare medians. Markers of glomerular (creatinine) and tubular [beta 2 (β₂)-microglobulin, uromodulin, osmolality] functions were correlated with inflammatory biomarkers (Spearman test).

RESULTS

An intense inflammatory profile was identified, with significantly increased concentrations of urinary IL-2, IL-4, IL-6, TNF, sTNFRI, sTNFRII, IFN-γ, MCP-1/CCL2, eotaxin/CCL11 and IL-8/CXCL8 in the PUV group compared to the controls. The same was observed for the anti-inflammatory cytokine IL-10 and for the fibrogenic mediator TGF-β. In the correlation analysis, β₂-microglobulin positively correlated with the presence of MCP-1/CCL2, sTNFRI and eotaxin/CCL11 and negatively correlated with the presence of creatinine.

CONCLUSIONS

This study shows that inflammatory molecules are already increased in fetuses with PUV at the mean gestational age of 22 weeks, suggesting a physiopathological role for inflammation just after the embryological formation of the urethral membrane.

Genetic, environmental, and epigenetic factors involved in CAKUT

Congenital anomalies of the kidney and urinary tract (CAKUT) refer to a spectrum of structural renal malformations and are the leading cause of end-stage renal disease in children. The genetic diagnosis of CAKUT has proven to be challenging due to genetic and phenotypic heterogeneity and incomplete genetic penetrance. Monogenic causes of CAKUT have been identified using different approaches, including single gene screening, and gene panel and whole exome sequencing. The majority of the identified mutations, however, lack substantial evidence to support a pathogenic role in CAKUT. Copy number variants or single nucleotide variants that are associated with CAKUT have also been identified. Numerous studies support the influence of epigenetic and environmental factors on kidney development and the natural history of CAKUT, suggesting that the pathogenesis of this syndrome is multifactorial. In this Review we describe the current knowledge regarding the genetic susceptibility underlying CAKUT and the approaches used to investigate the genetic basis of CAKUT. We outline the associated environmental risk factors and epigenetic influences on CAKUT and discuss the challenges and strategies used to fully address the involvement and interplay of these factors in the pathogenesis of the disease.

Next-generation sequencing for research and diagnostics in kidney disease

The advent of next-generation sequencing technologies has enabled genetic nephrology research to move beyond single gene analysis to the simultaneous investigation of hundreds of genes and entire pathways. These new sequencing approaches have been used to identify and characterize causal factors that underlie inherited heterogeneous kidney diseases such as nephronophthisis and congenital anomalies of the kidney and urinary tract. In this Review, we describe the development of next-generation sequencing in basic and clinical research and discuss the implementation of this novel technology in routine patient management. Widespread use of targeted and nontargeted approaches for gene identification in clinical practice will require consistent phenotyping, appropriate disease modelling and collaborative efforts to combine and integrate data analyses. Next-generation sequencing is an exceptionally promising technique that has the potential to improve the management of patients with inherited kidney diseases. However, identifying the molecular mechanisms that lead to renal developmental disorders and ciliopathies is difficult. A major challenge in the near future will be how best to integrate data obtained using next-generation sequencing with personalized medicine, including use of high-throughput disease modelling as a tool to support the clinical diagnosis of kidney diseases.