Identification of a novel UMOD mutation (c. 163G>A) in a Brazilian family with autosomal dominant tubulointerstitial kidney disease

Autosomal dominant tubulointerstitial kidney disease (ADTKD) is characterized by autosomal dominant inheritance, progressive chronic kidney disease, and a bland urinary sediment. ADTKD is most commonly caused by mutations in the UMOD gene encoding uromodulin (ADTKD-UMOD). We herein report the first confirmed case of a multi-generational Brazilian family with ADTKD-UMOD, caused by a novel heterozygous mutation (c.163G>A, GGC→AGC, p.Gly55Ser) in the UMOD gene. Of 41 family members, 22 underwent genetic analysis, with 11 individuals found to have this mutation. Three affected individuals underwent hemodialysis, one peritoneal dialysis, and one patient received a kidney transplant from a family member later found to be genetically affected. Several younger individuals affected with the mutation were also identified. Clinical characteristics included a bland urinary sediment in all tested individuals and a kidney biopsy in one individual showing tubulointerstitial fibrosis. Unlike most other reported families with ADTKD-UMOD, neither gout nor hyperuricemia was found in affected individuals. In summary, we report a novel UMOD mutation in a Brazilian family with 11 affected members, and we discuss the importance of performing genetic testing in families with inherited kidney disease of unknown cause.

Fate of Neutrophils during the Recovery Phase of Ischemia/Reperfusion Induced Acute Kidney Injury

Effective clearance of inflammatory cells is required for resolution of inflammation. Here, we show in vivo evidence that apoptosis and reverse transendothelial migration (rTEM) are important mechanisms in eliminating neutrophils and facilitating recovery following ischemia/reperfusion injury (IRI) of the kidney. The clearance of neutrophils was delayed in the Bax knockout (KO)BM → wild-type (WT) chimera in which bone marrow derived cells are partially resistant to apoptosis, compared to WTBM → WT mice. These mice also showed delayed functional, histological recovery, increased tissue cytokines, and accelerated fibrosis. The circulating intercellular adhesion molecule-1 (ICAM-1)+ Gr-1+ neutrophils displaying rTEM phenotype increased during the recovery phase and blockade of junctional adhesion molecule-C (JAM-C), a negative regulator of rTEM, resulted in an increase in circulating ICAM-1+ neutrophils, faster resolution of inflammation and recovery. The presence of Tamm-Horsfall protein (THP) in circulating ICAM-1+ neutrophils could suggest that they are derived from injured kidneys. In conclusion, we suggest that apoptosis and rTEM are critically involved in the clearance mechanisms of neutrophils during the recovery phase of IRI.

Uromodulin: a new biomarker of fetal renal function? / Uromodulina: um novo biomarcador de função renal fetal?

Abstract Introduction: Obstructive uropathies are main diseases affecting the fetus. Early diagnosis allows to establish the appropriate therapy to minimize the risk of damage to kidney function at birth. Biochemical markers have been used to predict the prognosis of renal function in fetuses. Uromodulin, also known by Tamm-Horsfall protein (THP) is exclusively produced in the kidneys and in normal conditions is the protein excreted in larger amounts in human urine. It plays important roles in kidneys and urinary tract. Also it participates in ion transport processes, interact with various components of the immune system and has a role in defense against urinary tract infections. Moreover, this protein was proved to be a good marker of renal function in adult patients with several renal diseases. Objective: To evaluate if uromodulin is produced and eliminated by the kidneys during fetal life by analyzing fetal urine and amniotic fluid and to establish correlation with biochemical parameter of renal function already used in Fetal Medicine Center at the Clinic Hospital of UFMG (CEMEFE/HC). Methods: Between 2013 and 2015, were selected 29 fetuses with indication of invasive tests for fetal diagnosis in monitoring at the CEMEFE/HC. Results: The determination of uromodulin was possible and measurable in all samples and showed statistically significant correlation with the osmolarity. Conclusion: There was a tendency of lower levels of Uromodulin values in fetuses with severe renal impairment prenatally. Thus, high levels of this protein in fetal amniotic fluid or fetal urine dosages possibly mean kidney function preserved.

Resumo Introdução: Uropatias obstrutivas estão entre as principais doenças que acometem o feto. O diagnóstico precoce destas doenças permite estabelecer a terapêutica adequada, visando minimizar os riscos de danos à função renal no nascimento. Os marcadores bioquímicos têm sido utilizados na predição do prognóstico da função renal em fetos. A uromodulina, também chamada de proteína de Tamm-Horsfall (THP), é produzida exclusivamente nos rins, e em condições normais, é a proteína excretada em maior volume na urina humana. Ela desempenha importantes funções nos rins e trato urinário. Participa dos processos de transporte de íons, interage com vários componentes do sistema imunológico e possui papel na defesa contra infecções do trato urinário. Além disso, se mostrou um bom biomarcador de função renal em adultos portadores de diversas doenças renais. Objetivos: Avaliar se a uromodulina é produzida e eliminada pelos rins durante a vida fetal através da análise de urina fetal e líquido amniótico, além de estabelecer correlação com o parâmetro bioquímico de função renal já utilizado no Centro de Medicina Fetal do Hospital das Clínicas da UFMG (CEMEFE/HC). Métodos: Entre 2013 e 2015, foram selecionados 29 fetos com indicação de exames invasivos para diagnóstico fetal em acompanhamento no CEMEFE/HC. Resultados: A dosagem da uromodulina foi possível e quantificável em todas as amostras e mostrou correlação significativa com a osmolaridade. Conclusão: A uromodulina mostrou uma tendência em apresentar valores reduzidos em fetos com grave comprometimento renal no pré-natal. Assim, valores elevados desta proteína em dosagens de urina fetal ou líquido amniótico podem significar uma função renal preservada.

Biomarker detection in urinary proteome of prostate cancer by nanoflow LC-MS/MS

INTRODUCTION: Urinary proteomics provides a wealth of information in the identification of protein markers associated with various diseases such as in carcinoma. With the increasing incidence of prostate cancer and the lack of sensitivity and specificity of prostate specific antigen, the simultaneous identification of an alternative protein biomarker through urinary proteomics is encouraging. Urine, which has similar proteins with serum, makes it an ideal alternative biofluid wherein the collection is easy and non-invasive.METHODS: Urinary proteins were separated by gradient SDS-PAGE followed by in-gel digestion and organic/buffer peptide extraction. The protein biomarkers in prostate cancer patients and control subjects were identified via LC-MS/MS and submitted to Protein Prospector where the peptide fragmentation of sequence was analyzed and compared with the SwissProt database.RESULTS: A panel of three protein biomarkers for the early detection of prostate cancer were identified: transthyretin, hemoglobin subunit alpha and hemoglobin sububit beta. The presence of these three biomarkers is associated with high Gleason scores and TNM stages but not with PSA level. Uromodulin and mannan binding lectin serine protease cancer from BPH. The study also revealed the divergence of the urinary proteome of the cancer patients from the urinary proteome of the control with BPH suggesting the fundamental differences in benign and malignant growth of the prostate epithelial cells. Another highlight of the study was the identification of oxidation of pro63 of transthyretin in patient 3. The proposed role of the post translational modification in pro63 of transthyretinin in the mechanism of prostate carcinogenesis remains to be defined and warrants further study.CONCLUSION: Our study was able to establish the homology of urine proteome among the controls and its divergence from the patients afflicted with prostate cancer by simultaneously comparing their urine proteomes leading to the identification of a distinct panel of biomarkers, namely, transthyretin, hemoglobin subunit alpha and hemoglobin subunit beta. Uromodulin and mannan binding lectin serine protease 2 are the additional biomarkers that can distinguish prostate cancer from BPH. Due to limitations in the number of controls and patients, only preliminary findings and their significance were shown. These findings need to be confirmed in future investigations using larger sample size for both the controls and the patients.

A Novel UMOD Mutation (c.187T>C) in a Korean Family with Juvenile Hyperuricemic Nephropathy

Familial juvenile hyperuricemic nephropathy (FJHN; OMIM 162000) is an autosomal dominant disorder characterized by hyperuricemia and gouty arthritis due to reduced kidney excretion of uric acid and progressive renal failure. Gradual progressive interstitial renal disease, with basement membrane thickening and glomerulosclerosis resulting from fibrosis, starts in early life. In most cases of FJHN, uromodulin gene (UMOD) is responsible for the disease; however, there has been only one report of a genetically confirmed FJHN family in Korea. Here we report another Korean family with FJHN, in which three male members. a father and 2 sons.developed gout and progressive renal insufficiency. The clinical, laboratory, and radiological findings were consistent with FJHN, and renal biopsy showed chronic parenchymal damage, which can be found in FJHN but is not specific to this disease. In order to confirm the diagnosis, sequence analysis of the UMOD was performed, and a novel heterozygous missense variant (c.187T>C; p.Cys63Arg) in exon 3 was identified. We assume that this variant is likely to be the causative mutation in this family, as the variant segregated with the disease. In addition, approximately two-thirds of the known mutations lead to a cysteine amino acid change in uromodulin, and all such variants have been shown to cause UMOD-associated kidney disease. In summary, we report a Korean FJHN family with three affected members by genetic analysis of the UMOD, and provide the first report of a novel heterozygous missense mutation.

Familial Juvenile Hyperuricemic Nephropathy and Uromodulin Gene Mutation

Familial Juvenile hyperuricemic nephropathy (FJHN) is a rare autosomal dominant disorder, characterized by early onset of hyperuricemia, gout and progressive kidney disease. Hyperuricemia prior to renal impairment and decreased fractional excretion of uric acid are hallmarks of FJHN. Renal dysfunction gradually appears early in life and results in end-stage renal disease usually between the ages of 20 and 70 years. FJHN is mostly caused by mutations in the uromodulin gene located at 16p12. The course of FJHN is highly variable. Treatment includes management for hyperuricemia, gout and progressive kidney disease. Individuals with gout have been usually treated with allopurinol. But controversy exists as to whether uric acid lowering therapy prevents the progression of chronic kidney disease.

Mangiferin promotes uric acid excretion and kidney function improvement and modulates related renal transporters in hyperuricemic mice / 药学学报

The effects of mangiferin on uric acid excretion, kidney function and related renal transporters were investigated in hyperuricemic mice induced by potassium oxonate. Mice were divided into normal control group, and 5 hyperuricemic groups with model control, 50, 100, and 200 mg x kg(-1) mangiferin, and 5 mg x kg(-1) allopurinol. Mice were administered by gavage once daily with 250 mg x kg(-1) potassium oxonate for seven consecutive days to create the model. And 3 doses of mangiferin were orally initiated on the day 1 h after potassium oxonate was given, separately. Serum uric acid, creatinine and urea nitrogon levels, as well as urinary uric acid creatinine levels were measured. Mouse uromodulin (mUMOD) levels in serum, urine and kidney were determined by ELISA method. The mRNA and protein levels of related renal transporters were assayed by RT-PCR and Western blotting methods, respectively. Compared to model group, mangiferin significantly reduced serum uric acid, creatinine and urea nitrogon levels, increased 24 h uric acid and creatinine excretion, and fractional excretion of uric acid in hyperuricemic mice, exhibiting uric acid excretion enhancement and kidney function improvement. Mangiferin was found to down-regulate mRNA and protein levels of urate transporter 1 (mURAT1) and glucose transporter 9 (mGLUT9), as well as up-regulate organic anion transporter 1 (mOAT1) in the kidney of hyperuricemic mice. These findings suggested that mangiferin might enhance uric acid excretion and in turn reduce serum uric acid level through the decrease of uric acid reabsorption and the increase of uric acid secretion in hyperuricemic mice. Moreover, mangiferin remarkably up-regulated expression levels of renal organic cation and carnitine transporters (mOCT1, mOCT2, mOCTN1 and mOCTN2), increased urine mUMOD levels, as well as decreased serum and kidney mUMOD levels in hyperuricemic mice, which might be involved in mangiferin-mediated renal protective action.

A Case of Familial Juvenile Hyperuricemic Nephropathy with Novel Uromodulin Gene Mutation, a Novel Heterozygous Missense Mutation in Korea

Familial Juvenile hyperuricemic nephropathy (FJHN, OMIM #162000) is a rare autosomal dominant disorder characterized by hyperuricemia with renal uric acid under-excretion, gout and chronic kidney disease. In most but not all families with FJHN, genetic studies have revealed mutations in the uromodulin (UMOD) gene located on chromosome 16p11-p13. We here described a novel heterozygous missense mutation (c.1382C>A causing p.Ala461Glu) in an affected 16-year-old male with hyperuricemia, gout and chronic kidney disease. His father was also affected and the UMOD mutation was found to segregate with the disease. There has been only one case report of Korean family with FJHN, which has not been diagnosed by genetic study. This is the first report of genetically diagnosed FJHN in Korea.

Diagnosis and Management of Interstitial Cystitis/ Painful Bladder Syndrome

Much has changed in our understanding of the interstitial cystitis/painful bladder syndrome (IC/PBS) over time. The International Continence Society (ICS) prefers the term Painful Bladder Syndrome (PBS) defined as "the complaint of suprapubic pain related to bladder filling, accompanied by other symptoms such as increased daytime and night-time frequency, in the absence of proven urinary infection or other obvious pathology". Interstitial cystitis is a clinical diagnosis primarily based on symptoms of urgency/frequency and pain in the bladder and or pelvis. The pathogenesis of IC is still not completely understood, but it is likely multifactorial. The major etiologic theories include abnormality of the bladder urothelium, bladder mast cell activation, bladder inflammation, and altered bladder innervation. The sensitivity and specificity of urinary markers and the potassium sensitivity test have not been prospectively studied. Antiproliferative factor and Tamm-Horsfall protein are novel tests that may prove to be worthwhile pending future studies. Management includes patient education, dietary and lifestyle counseling, oral therapy, intravesical therapy, and surgery. Recently, the European Society for the Study of Interstitial Cystitis (ESSIC) proposed a new nomenclature and classification system. This article discusses recent data and outlines current concepts of IC/PBS.

Morphologic Characterization of Polycystic Kidney in inv Transgenic Mouse

The aim of this study was to characterize the morphology of a polycystic kidney which was found in 100% of the transgenic mice homozygous for inv mutation and to gain insight into the pathogenesis of inherited polycystic kidney disease during the pre- and postnatal periods. The fetal and postnatal kidneys from the homozygous and heterozygous transgenic mice were examined by the light, transmission and scanning electron microscopes, image analyzer, and an immunohistochemistry utilizing the antibodies specific for each segment of the renal tubules (Tetragonolobus purpureas, Arachis hypogaea, Tamm-Horsfall protein, AE1/AE3, EMA, vimentin, Phaseolus vulgaris) was performed to determine the site of origin of renal cysts. Two developmental phases of a cystic disease were identified. The first phase, seen in fetal kidneys, was characterized by dilatation mainly of the proximal tubules and a few distal tubules. The later phase, in postnatal period, was characterized by progressive enlargement of the kidneys due to mainly cystic change of the collecting ducts, which distorted the normal architecture of both cortex and medulla and almost completely replaced the renal parenchyma. The cystic dilatation involved all segments of the nephron and the collecting duct as well as the Bowman's spaces of glomeruli. The epithelial cell hyperplasia was found as a micropolyp formation within the renal cysts and an increase in PCNA positive cells. These findings suggest that a cyst is not simply a ballooning of a renal tubule and the stretching of cells, formerly thought to be due to an altered compliance of an abnormal basement membrane, but indeed the result of increased numbers of tubular epithelial cells.

The Comparison of the Urine RBC Phase Contrast Microscopy and Immunoperoxidase Stain in Differentiation of Hematuria / 대한신장학회잡지

Differentiation of renal(RH) and non-renal(NRH) hematuria is important in the diagnosis and treatment of the patients with hematuria. Recently, urine RBC immunoperoxidase(IPx) staining method was developed, but there was no report on the usefulness of IPx in Korea. We validated the usefulness of IPx by comparing with the PCM. Both PCM and IPx were performed at the same time in 26 patients with RH confirmed by renal biopsy and 23 patients with NRH confirmed by radiologic and/or pathologic studies who were admitted to Chungbuk National University Hospital from January 1996 to December 1996. The age of RH and NRH group were 36.6+/-15.0 and 56.5+/-22.2 years. 35.7+/-30.4% of urine RBC were stained by IPx in RH group and only 1.6+/-4.4% were stained in NRH group(P<0.001). 23.4+/-29.9% of urine RBC by PCM were counted as dysmorphic RBC in RH group and 5.7+/-13.6% were counted in NRH group(P<0.05). At the cut-off value of 20%, the sensitivity and specificity of IPx were 57.7% and 100%. At the cut-off value of 30%, those of PCM were 30.9% and 95.7%, respectively. When comparing overall test performance by calculating AUCs of ROC(receiver operating characteristics) curve, IPx was better than PCM. IPx was better than PCM in localizing the origin of hematuria. The NRH might be excluded when IPx(+) cells are more than 20% of total urine RBC.