Zika Virus Growth in Human Kidney Cells Is Restricted by an Elevated Glucose Level.

Mosquito-borne Zika virus (ZIKV) became a real threat to human health due to the lack of vaccine and effective antiviral treatment. The virus has recently been responsible for a global outbreak leading to millions of infected cases. ZIKV complications were highlighted in adults with Guillain-Barré syndrome and in newborns with increasing numbers of congenital disorders ranging from mild developmental delays to fatal conditions. The ability of ZIKV to establish a long-term infection in diverse organs including the kidneys has been recently documented but the consequences of such a viral infection are still debated. Our study aimed to determine whether the efficiency of ZIKV growth in kidney cells relates to glucose concentration. Human kidney HK-2 cells were infected with different ZIKV strains in presence of normal and high glucose concentrations. Virological assays showed a decrease in viral replication without modifying entry steps (viral binding, internalization, fusion) under high glucose conditions. This decrease replication was associated with a lower virus progeny and increased cell viability when compared to ZIKV-infected HK-2 cells in normal glucose concentration. In conclusion, we showed for the first time that an elevated glucose level influences ZIKV replication level with an effect on kidney cell survival.

Phenolic Profile of Herbal Infusion and Polyphenol-Rich Extract from Leaves of the Medicinal Plant Antirhea borbonica: Toxicity Assay Determination in Zebrafish Embryos and Larvae.

Antirhea borbonica (A. borbonica) is an endemic plant from the Mascarene archipelago in the Indian Ocean commonly used in traditional medicine for its health benefits. This study aims (1) at exploring polyphenols profiles from two types of extracts-aqueous (herbal infusion) and acetonic (polyphenol rich) extracts from A. borbonica leaves-and (2) at evaluating their potential toxicity in vivo for the first time. We first demonstrated that, whatever type of extraction is used, both extracts displayed significant antioxidant properties and acid phenolic and flavonoid contents. By using selective liquid chromatography-tandem mass spectrometry, we performed polyphenol identification and quantification. Among the 19 identified polyphenols, we reported that the main ones were caffeic acid derivatives and quercetin-3-O-rutinoside. Then, we performed a Fish Embryo Acute Toxicity test to assess the toxicity of both extracts following the Organisation for Economic Cooperation and Development (OECD) guidelines. In both zebrafish embryos and larvae, the polyphenols-rich extract obtained by acetonic extraction followed by evaporation and resuspension in water exhibits a higher toxic effect with a median lethal concentration (LC50: 5.6 g/L) compared to the aqueous extract (LC50: 20.3 g/L). Our data also reveal that at non-lethal concentrations of 2.3 and 7.2 g/L for the polyphenol-rich extract and herbal infusion, respectively, morphological malformations such as spinal curvature, pericardial edema, and developmental delay may occur. In conclusion, our study strongly suggests that the evaluation of the toxicity of medicinal plants should be systematically carried out and considered when studying therapeutic effects on living organisms.

Identification of Symptomatic Fetuses Infected with Cytomegalovirus Using Amniotic Fluid Peptide Biomarkers.

Cytomegalovirus (CMV) is the most common cause of congenital infection, and is a major cause of sensorineural hearing loss and neurological disabilities. Evaluating the risk for a CMV infected fetus to develop severe clinical symptoms after birth is crucial to provide appropriate guidance to pregnant women who might have to consider termination of pregnancy or experimental prenatal medical therapies. However, establishing the prognosis before birth remains a challenge. This evaluation is currently based upon fetal imaging and fetal biological parameters, but the positive and negative predictive values of these parameters are not optimal, leaving room for the development of new prognostic factors. Here, we compared the amniotic fluid peptidome between asymptomatic fetuses who were born as asymptomatic neonates and symptomatic fetuses who were either terminated in view of severe cerebral lesions or born as severely symptomatic neonates. This comparison allowed us to identify a 34-peptide classifier in a discovery cohort of 13 symptomatic and 13 asymptomatic neonates. This classifier further yielded 89% sensitivity, 75% specificity and an area under the curve of 0.90 to segregate 9 severely symptomatic from 12 asymptomatic neonates in a validation cohort, showing an overall better performance than that of classical fetal laboratory parameters. Pathway analysis of the 34 peptides underlined the role of viral entry in fetuses with severe brain disease as well as the potential importance of both beta-2-microglobulin and adiponectin to protect the injured fetal brain infected with CMV. The results also suggested the mechanistic implication of the T calcium channel alpha-1G (CACNA1G) protein in the development of seizures in severely CMV infected children. These results open a new field for potential therapeutic options. In conclusion, this study demonstrates that amniotic fluid peptidome analysis can effectively predict the severity of congenital CMV infection. This peptidomic classifier may therefore be used in clinical settings during pregnancy to improve prenatal counseling.

Hepatocyte Nuclear Factor-1ß Controls Mitochondrial Respiration in Renal Tubular Cells.

AKI is a frequent condition that involves renal microcirculation impairment, infiltration of inflammatory cells with local production of proinflammatory cytokines, and subsequent epithelial disorders and mitochondrial dysfunction. Peroxisome proliferator-activated receptor γ coactivator 1-α (PPARGC1A), a coactivator of the transcription factor PPAR-γ that controls mitochondrial biogenesis and function, has a pivotal role in the early dysfunction of the proximal tubule and the subsequent renal repair. Here, we evaluated the potential role of hepatocyte nuclear factor-1ß (HNF-1ß) in regulating PPARGC1A expression in AKI. In mice, endotoxin injection to induce AKI also induced early and transient inflammation and PPARGC1A inhibition, which overlapped with downregulation of the HNF-1ß transcriptional network. In vitro, exposure of proximal tubule cells to the inflammatory cytokines IFN-γ and TNF-α led to inhibition of HNF-1ß transcriptional activity. Moreover, inhibition of HNF-1ß significantly reduced PPARGC1A expression and altered mitochondrial morphology and respiration in proximal tubule cells. Chromatin immunoprecipitation assays and PCR analysis confirmed HNF-1ß binding to the Ppargc1a promoter in mouse kidneys. We also demonstrated downregulation of renal PPARGC1A expression in a patient with an HNF1B germinal mutation. Thus, we propose that HNF-1ß links extracellular inflammatory signals to mitochondrial dysfunction during AKI partly via PPARGC1A signaling. Our findings further strengthen the view of HNF1B-related nephropathy as a mitochondrial disorder in adulthood.

Increased urine acylcarnitines in diabetic ApoE-/- mice: Hydroxytetradecadienoylcarnitine (C14:2-OH) reflects diabetic nephropathy in a context of hyperlipidemia.

Hyperlipidemia is a risk factor for initiation and progression of diabetic nephropathy but the metabolic pathways altered in the diabetic kidney in a context of hyperlipidemia remain incompletely described. Assuming that changes in urine composition reflect the alteration of renal metabolism and function, we analyzed the urine metabolite composition of diabetic (streptozotocin-treatment) and control (non diabetic) ApoE-/- mice fed a high cholesterol diet using targeted quantitative metabolomics. Urine metabolome was also compared to the plasma metabolome of the same animals. As previously shown, urine albuminuria/urine creatinine ratio (uACR) and glomerular area and plasma lipids (cholesterol, triglycerides) were more elevated in diabetic mice compared to control. After adjustment to urine creatinine, the abundance of 52 urine metabolites was significantly different in diabetic mice compared to control. Among them was a unique metabolite, C14:2-OH (3-hydroxytetradecadienoylcarnitine) that, in diabetic mice, was positively and significantly correlated with uACR, glomerular hypertrophy, blood glucose and plasma lipids. That metabolite was not detected in plasma. C14:2-OH is a long-chain acylcarnitine reminiscent of altered fatty acid beta oxidation. Other acylcarnitines, particularly the short chains C3-OH, C3-DC, C4:1, C5-DC, C5-M-DC, C5-OH that are reminiscent of altered oxidation of branched and aromatic amino acids were also exclusively detected in urine but were only correlated with plasma lipids. Finally, the renal gene expression of several enzymes involved in fatty acid and/or amino acid oxidation was significantly reduced in diabetic mice compared to control. This included the bifunctional enoyl-CoA hydratase/3-hydroxyacyl-CoA (Ehhadh) that might play a central role in C14:2-OH production. This study indicate that the development of diabetes in a context of hyperlipidemia is associated with a reduced capacity of kidney to oxidize fatty acids and amino acids with the consequence of an elevation of urinary acetylcarnitines including C14:2-OH that specifically reflects diabetic nephropathy.

Asymptomatic circulating T-cell clone cause renal polymorphic inflammatory fibrosis.

BACKGROUND: Renal complications of non-Hodgkin lymphoma encompass a wide spectrum of monoclonal Ig-related pathologies. Clonal circulating T cells can also be associated with non-renal autoimmune disorders induced by overproduction of specific patterns of cytokines or unbalanced lymphocytes sub-populations. METHODS: Immunophenotyping of circulating T cells and TCR gene restriction analysis using Biomed-2 protocol. NF-κB staining and mRNA quantification of inflammatory genes in HK-2 epithelial renal cells exposed to supernatants of peripheral blood mononuclear cells with clonal T-cell population. RESULTS: Here, we could identify a persistent clonal T-cell population, only characterized by in-depth immunophenotyping of circulating lymphocytes and using multiplex PCR analysis of TCR gene rearrangements, in two patients with polymorphic inflammatory renal fibrosis of unknown origin. Using an in vitro approach, we could demonstrate that peripheral blood mononuclear cells including the clonal population can trigger a phenotype switch of epithelial renal cells from a quiescent state to a pro-inflammatory state characterized by NF-κB nuclear translocation and overexpression of inflammatory cytokine or chemokine. CONCLUSION: These preliminary data suggest that circulating T-cell clones may directly activate epithelial renal cells or promote a T-/B-cell population with autoimmune reactive properties against kidney cells, which, in the absence of overt renal lymphoma infiltration, lead to the subsequent inflammatory renal fibrotic phenotype.

The role of urinary peptidomics in kidney disease research.

Urinary peptidomics focuses on endogenous urinary peptide content. Many studies now show the usefulness of this approach for the discovery and validation of biomarkers in kidney diseases that are as varied as chronic kidney disease, acute kidney injury, congenital anomalies of the kidney and the urinary tract, and polycystic kidney disease. Most studies focus on chronic kidney disease and demonstrate that urinary peptidome analysis can substantially contribute to early detection and stratification of patients with chronic kidney disease. A number of multicenter studies are ongoing that aim further validation in a clinical setting and broaden the applicability of urinary peptides. The association of urinary peptides with kidney disease also starts to deliver information on the pathophysiology of kidney disease with emphasis on extracellular matrix remodeling. Bioinformatic peptide centric tools have been developed that allow to model the changes in protease activity involved in kidney disease, based on the urinary peptidome content. A novel application of urinary peptidome analysis is the back-translation of results obtained in humans to animals for animal model validation and improvement of readout in these preclinical models. In conclusion, urinary peptidomics not only contribute to detection and stratification of kidney disease in the clinic, but might also create a new impulse in drug discovery through better insight in the pathophysiology of disease and optimized translatability of animal models.

Epidermal growth factor and kidney disease: a long-lasting story.

Epidermal growth factor has been previously associated with kidney disease. In this issue of Kidney International, Betz et al. (2016) link urinary epidermal growth factor abundance with an increased risk of the development of diabetic nephropathy in a novel animal model of diabetic nephropathy and in a large cohort of patients with type 2 diabetes. Although the clinical value of these observations needs to be confirmed in further studies, these observations further strengthen the tight link between epidermal growth factor and kidney disease.

Urinary peptidomics provides a noninvasive humanized readout of diabetic nephropathy in mice.

Nephropathy is among the most frequent complications of diabetes and the leading cause of end-stage renal disease. Despite the success of novel drugs in animal models, the majority of the subsequent clinical trials employing those drugs targeting diabetic nephropathy failed. This lack of translational value may in part be due to an inadequate comparability of human disease and animal models that often capture only a few aspects of disease. Here we overcome this limitation by developing a multimolecular noninvasive humanized readout of diabetic nephropathy based on urinary peptidomics. The disease-modified urinary peptides of 2 type 2 diabetic nephropathy mouse models were identified and compared with previously validated urinary peptide markers of diabetic nephropathy in humans to generate a classifier composed of 21 ortholog peptides. This classifier predicted the response to disease and treatment with inhibitors of the renin-angiotensin system in mice. The humanized classifier was significantly correlated with glomerular lesions. Using a human type 2 diabetic validation cohort of 207 patients, the classifier also distinguished between patients with and without diabetic nephropathy, and their response to renin-angiotensin system inhibition. Thus, a combination of multiple molecular features common to both human and murine disease could provide a significant change in translational drug discovery research in type 2 diabetic nephropathy.

Acute Bradykinin Receptor Blockade During Hemorrhagic Shock in Mice Prevents the Worsening Hypotensive Effect of Angiotensin-Converting Enzyme Inhibitor.

OBJECTIVES: Angiotensin-converting enzyme inhibitors are associated with deleterious hypotension during anesthesia and shock. Because the pharmacologic effects of angiotensin-converting enzyme inhibitors are partly mediated by increased bradykinin B2 receptor activation, this study aimed to determine the impact of acute B2 receptor blockade during hemorrhagic shock in angiotensin-converting enzyme inhibitor-treated mice. DESIGN: In vivo study. SETTING: University research unit. SUBJECTS: C57/Bl6 mice. INTERVENTIONS: The hemodynamic effect of B2 receptor blockade using icatibant (B2 receptor antagonist) was studied using a pressure-targeted hemorrhagic shock and a volume-targeted hemorrhagic shock. Animals were anesthetized with ketamine and xylazine (250 mg/kg and 10 mg/kg, respectively), intubated using intratracheal cannula, and ventilated (9 mL/kg, 150 min). Five groups were studied: 1) sham-operated animals, 2) control shocked mice, 3) shocked mice treated with ramipril for 7 days (angiotensin-converting enzyme inhibitors) before hemorrhagic shock, 4) shocked mice treated with angiotensin-converting enzyme inhibitors and a single bolus of icatibant (HOE-140) immediately before anesthesia (angiotensin-converting enzyme inhibitors + icatibant), and 5) shocked mice treated with a single bolus of icatibant. One hour after volume-targeted hemorrhagic shock, blood lactate was measured to evaluate organ failure. MEASUREMENTS AND MAIN RESULTS: During pressure-targeted hemorrhagic shock, the mean blood volume withdrawn was significantly lower in the angiotensin-converting enzyme inhibitor group than in the other groups (p < 0.001). During volume-targeted hemorrhagic shock, icatibant prevented blood pressure lowering in the angiotensin-converting enzyme inhibitor group (p < 0.001). Blood lactate was significantly higher in the angiotensin-converting enzyme inhibitor group than in the other groups, particularly the HOE groups. CONCLUSIONS: During hemorrhagic shock, acute B2 receptor blockade significantly attenuates the deleterious hemodynamic effect of angiotensin-converting enzyme inhibitor treatment in mice. This beneficial effect of B2 receptor blockade is rapidly reached and sustained with a single bolus of icatibant. This benefit could be of interest in angiotensin-converting enzyme inhibitor-treated patients during both emergency anesthesia and resuscitation.

Label-free quantitative urinary proteomics identifies the arginase pathway as a new player in congenital obstructive nephropathy.

Obstructive nephropathy is a frequently encountered situation in newborns. In previous studies, the urinary peptidome has been analyzed for the identification of clinically useful biomarkers of obstructive nephropathy. However, the urinary proteome has not been explored yet and should allow additional insight into the pathophysiology of the disease. We have analyzed the urinary proteome of newborns (n = 5/group) with obstructive nephropathy using label free quantitative nanoLC-MS/MS allowing the identification and quantification of 970 urinary proteins. We next focused on proteins exclusively regulated in severe obstructive nephropathy and identified Arginase 1 as a potential candidate molecule involved in the development of obstructive nephropathy, located at the crossroad of pro- and antifibrotic pathways. The reduced urinary abundance of Arginase 1 in obstructive nephropathy was verified in independent clinical samples using both Western blot and MRM analysis. These data were confirmed in situ in kidneys obtained from a mouse obstructive nephropathy model. In addition, we also observed increased expression of Arginase 2 and increased total arginase activity in obstructed mouse kidneys. mRNA expression analysis of the related arginase pathways indicated that the pro-fibrotic arginase-related pathway is activated during obstructive nephropathy. Taken together we have identified a new actor in the development of obstructive nephropathy in newborns using quantitative urinary proteomics and shown its involvement in an in vivo model of disease. The present study demonstrates the relevance of such a quantitative urinary proteomics approach with clinical samples for a better understanding of the pathophysiology and for the discovery of potential therapeutic targets.

Specific macrophage subtypes influence the progression of rhabdomyolysis-induced kidney injury.

Rhabdomyolysis can be life threatening if complicated by AKI. Macrophage infiltration has been observed in rat kidneys after glycerol-induced rhabdomyolysis, but the role of macrophages in rhabdomyolysis-induced AKI remains unknown. Here, in a patient diagnosed with rhabdomyolysis, we detected substantial macrophage infiltration in the kidney. In a mouse model of rhabdomyolysis-induced AKI, diverse renal macrophage phenotypes were observed depending on the stage of the disease. Two days after rhabdomyolysis, F4/80(low)CD11b(high)Ly6b(high)CD206(low) kidney macrophages were dominant, whereas by day 8, F4/80(high)CD11b(+)Ly6b(low)CD206(high) cells became the most abundant. Single-cell gene expression analyses of FACS-sorted macrophages revealed that these subpopulations were heterogeneous and that individual cells simultaneously expressed both M1 and M2 markers. Liposomal clodronate-mediated macrophage depletion significantly reduced the early infiltration of F4/80(low)CD11b(high)Ly6b(high)CD206(low) macrophages. Furthermore, transcriptionally regulated targets potentially involved in disease progression, including fibronectin, collagen III, and chemoattractants that were identified via single-cell analysis, were verified as macrophage-dependent in situ. In vitro, myoglobin treatment induced proximal tubular cells to secrete chemoattractants and macrophages to express proinflammatory markers. At day 30, liposomal clodronate-mediated macrophage depletion reduced fibrosis and improved both kidney repair and mouse survival. Seven months after rhabdomyolysis, histologic lesions were still present but were substantially reduced with prior depletion of macrophages. These results suggest an important role for macrophages in rhabdomyolysis-induced AKI progression and advocate the utility of long-term follow-up for patients with this disease.

Pro-fibrotic activity of lysophosphatidic acid in adipose tissue: in vivo and in vitro evidence.

Lysophosphatidic acid (LPA) is a pro-fibrotic mediator acting via specific receptors (LPARs) and is synthesized by autotaxin, that increases with obesity. We tested whether LPA could play a role in adipose tissue (AT)-fibrosis associated with obesity. Fibrosis [type I, III, and IV collagens (COL), fibronectin (FN), TGFß, CTGF and αSMA] and inflammation (MCP1 and F4/80) markers were quantified: (i) in vivo in inguinal (IAT) and perigonadic (PGAT) AT from obese-diabetic db/db mice treated with the LPAR antagonist Ki16425 (5mg/kg/day ip for 7 weeks); and (ii) in vitro in human AT explants in primary culture for 72h in the presence of oleoyl-LPA (10µM) and/or Ki16425 (10µM) and/or the HIF-1α inhibitor YC-1 (100µM). Treatment of db/db mice with Ki16425 reduced Col I and IV mRNAs in IAT and PGAT while Col III mRNAs were only reduced in IAT. This was associated with reduction of COL protein staining in both IAT and PGAT. AT explants showed a spontaneous and time-dependent increase in ATX expression and production of LPA in the culture medium, along with increased levels of Col I and III, TGFß and αSMA mRNAs and of COL protein staining. In vitro fibrosis was blocked by Ki16425 and was further amplified by oleoyl-LPA. LPA-dependent in vitro fibrosis was blocked by co-treatment with YC1. Our results show that endogenous and exogenous LPA exert a pro-fibrotic activity in AT in vivo and in vitro. This activity could be mediated by an LPA1R-dependent pathway and could involve HIF-1α.

Pretransplant urinary proteome analysis does not predict development of chronic kidney disease after liver transplantation.

BACKGROUND & AIMS: Chronic kidney disease (CKD) is a common complication after liver transplantation. Kidney biopsies cannot be easily performed before liver transplantation to predict patients at high risk for CKD. The aim of our study was to determine whether pre-, peri- and post-transplant factors, as well as peptides present in preliver transplant urine samples were associated with loss in kidney function at 6 months post-transplantation using proteome analysis. METHODS: Eighty patients who underwent a liver transplantation and that had pretransplant glomerular filtration rate (GFR) value of ≥60 mL/min/1.73 m² (MDRD) were included in the study. RESULTS: GFR decreased significantly after transplantation. At month 6 post-transplantation, 40 patients displayed a CKD, i.e. eGFR of <60 mL/min/1.73 m², while the other 40 patients did not. Although thousands of peptides were identified, none was significantly associated with the development of CKD at 6 months after liver transplantation. Moreover, using a urinary peptidome classifier to detect preexisting CKD, no difference was found in CKD scores between the 2 groups. After analysis of a large number of pre-, peri- and post-transplant parameters, viral hepatitis as a cause for liver transplantation was the sole independent predictive factor for CKD. No difference in peptides with differential urinary abundance between patients who received a graft for virus related liver disease vs. all other causes of liver disease was observed. CONCLUSION: Urinary peptidome analysis before liver transplantation failed to identify a peptide pattern associated with the development of CKD at 6 months after liver transplantation.

Clinical proteomics in obstetrics and neonatology.

Clinical proteomics has been applied to the identification of biomarkers of obstetric and neonatal disease. We will discuss a number of encouraging studies that have led to potentially valid biomarkers in the context of Down's syndrome, preterm birth, amniotic infections, preeclampsia, intrauterine growth restriction and obstructive uropathies. Obtaining noninvasive biomarkers (e.g., from the maternal circulation, urine or cervicovaginal fluid) may be more feasible for obstetric diseases than for diseases of the fetus, for which invasive methods are required (e.g., amniotic fluid, fetal urine). However, studies providing validated proteomics-identified biomarkers are limited. Efforts should be made to save well-characterized samples of these invasive body fluids so that many valid biomarkers of pregnancy-related diseases will be identified in the coming years using proteomics based analysis upon adoption of 'clinical proteomics guidelines'.

The KUPNetViz: a biological network viewer for multiple -omics datasets in kidney diseases.

BACKGROUND: Constant technological advances have allowed scientists in biology to migrate from conventional single-omics to multi-omics experimental approaches, challenging bioinformatics to bridge this multi-tiered information. Ongoing research in renal biology is no exception. The results of large-scale and/or high throughput experiments, presenting a wealth of information on kidney disease are scattered across the web. To tackle this problem, we recently presented the KUPKB, a multi-omics data repository for renal diseases. RESULTS: In this article, we describe KUPNetViz, a biological graph exploration tool allowing the exploration of KUPKB data through the visualization of biomolecule interactions. KUPNetViz enables the integration of multi-layered experimental data over different species, renal locations and renal diseases to protein-protein interaction networks and allows association with biological functions, biochemical pathways and other functional elements such as miRNAs. KUPNetViz focuses on the simplicity of its usage and the clarity of resulting networks by reducing and/or automating advanced functionalities present in other biological network visualization packages. In addition, it allows the extrapolation of biomolecule interactions across different species, leading to the formulations of new plausible hypotheses, adequate experiment design and to the suggestion of novel biological mechanisms. We demonstrate the value of KUPNetViz by two usage examples: the integration of calreticulin as a key player in a larger interaction network in renal graft rejection and the novel observation of the strong association of interleukin-6 with polycystic kidney disease. CONCLUSIONS: The KUPNetViz is an interactive and flexible biological network visualization and exploration tool. It provides renal biologists with biological network snapshots of the complex integrated data of the KUPKB allowing the formulation of new hypotheses in a user friendly manner.

Dual effect of chemokine CCL7/MCP-3 in the development of renal tubulointerstitial fibrosis.

Most end-stage renal disease kidneys display accumulation of extracellular matrix (ECM) in the renal tubular compartment (tubular interstitial fibrosis - TIF) which is strongly correlated with the future loss of renal function. Although inflammation is a key event in the development of TIF, it can also have a beneficial anti-fibrotic role depending in particular on the stage of the pathology. Chemokines play an important role in monocyte extravasation in the inflammatory process. CCL2 has already been shown to be involved in the development of TIF but CCL7, a close relative of CCL2 and able to bind to similar receptors, has not been studied in renal disease. We therefore studied chemokine CCL7 in a model of unilateral ureteral obstruction (UUO)-induced TIF. We observed that the role of CCL7 differs depending on the stage of the pathology. In early stages (0-8 days), CCL7 deficient (CCL7-KO) mice displayed attenuated TIF potentially involving two mechanisms: an early (0-3 days) decrease of inflammatory cell infiltration followed (3-8 days) by a decrease in tubular ECM production independent of inflammation. In contrast, during later stages of obstruction (10-14 days), CCL7-KO mice displayed increased TIF which was again associated with reduced inflammation. Interestingly, the switch between this anti- to profibrotic effect was accompanied by an increased influx of immunosuppressive regulatory T cells. In conclusion, these results highlight for the first time a dual role for CCL7 in the development of renal TIF, deleterious in early stages but beneficial during later stages.

The KUPKB: a novel Web application to access multiomics data on kidney disease.

The information gathered from the large number of omics experiments in renal biology is underexplored, as it is scattered over many publications or held in supplemental data. To address this, we have developed an open-source Kidney and Urinary Pathway Knowledge Base (KUPKB) that facilitates simple exploration of these omics data. The KUPKB currently comprises 220 data sets (miRNA, mRNA, proteins, and metabolites) extracted from existing publications or databases. Researchers can explore the integrated data using the iKUP browser, and a simple template is provided to submit new omics data sets to the knowledge base. As an example of iKUP's use, we show how we identified, in silico, calreticulin as a protein induced in human interstitial fibrosis and tubular atrophy (IFTA) in chronic kidney transplant rejection; a link that would have been difficult to establish using existing Web-based tools. Using immunohistochemistry, we validated in vivo this in silico result in human and rat biopsies of IFTA, thus identifying calreticulin as a potential new player in chronic kidney transplant rejection. The KUPKB provides a simple tool that enables users to quickly survey a wide range of omics data sets and has been shown to facilitate rapid hypothesis generation in the context of renal pathophysiology.

Predicting the clinical outcome of congenital unilateral ureteropelvic junction obstruction in newborn by urinary proteome analysis.

We analyzed urinary polypeptides from individuals with neonatal ureteropelvic junction (UPJ) obstruction to predict which individuals with this condition will evolve toward obstruction that needs surgical correction. We identified polypeptides that enabled diagnosis of the severity of obstruction and validated these biomarkers in urine collected in a prospective blinded study. Using these noninvasive biomarkers, we were able to predict, several months in advance and with 94% precision, the clinical evolution of neonates with UPJ obstruction.

[Renal urinary shear stress: a novel actor in nephropathies]. / Quand l'urine cisaille les cellules rénales - Un nouveau rôle pour le shear stress dans les néphropathies.

The role of fluid shear stress is well established in vascular pathophysiology. However, urinary shear stress now also appears as a key mechanism in the regulation of renal function. In addition, there is a growing body of evidence showing that modified urinary shear stress is involved in the development of nephropathies. Therefore we review here the state-of-the-art on the pathophysiological roles of urinary shear stress.