Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0392525 (nephrolithiasis)
 2,669 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The evolution of specialized excretory cells is a cornerstone of the metazoan radiation, and the basic tasks performed by Drosophila and human renal systems are similar. The development of the Drosophila renal (Malpighian) tubule is a classic example of branched tubular morphogenesis, allowing study of mesenchymal-to-epithelial transitions, stem cell-mediated regeneration, and the evolution of a glomerular kidney. Tubule function employs conserved transport proteins, such as the Na(+), K(+)-ATPase and V-ATPase, aquaporins, inward rectifier K(+) channels, and organic solute transporters, regulated by cAMP, cGMP, nitric oxide, and calcium. In addition to generation and selective reabsorption of primary urine, the tubule plays roles in metabolism and excretion of xenobiotics, and in innate immunity. The gene expression resource FlyAtlas.org shows that the tubule is an ideal tissue for the modeling of renal diseases, such as nephrolithiasis and Bartter syndrome, or for inborn errors of metabolism. Studies are assisted by uniquely powerful genetic and transgenic resources, the widespread availability of mutant stocks, and low-cost, rapid deployment of new transgenics to allow manipulation of renal function in an organotypic context.
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PMID:Drosophila provides rapid modeling of renal development, function, and disease. 2092 30

Receptor-mediated endocytosis, involving megalin and cubilin, mediates renal proximal-tubular reabsorption and is decreased in Dent disease because of mutations of the chloride/proton antiporter, chloride channel-5 (CLC-5), resulting in low-molecular-weight proteinuria, hypercalciuria, nephrolithiasis, and renal failure. To facilitate studies of receptor-mediated endocytosis and the role of CLC-5, we established conditionally immortalized proximal-tubular epithelial cell lines (ciPTECs) from three patients with CLC-5 mutations (30:insH, R637X, and del132-241) and a normal male. Confocal microscopy using the tight junction marker zona occludens-1 (ZO-1) and end-binding protein-1 (EB-1), which is specific for the plus end of microtubules demonstrated that the ciPTECs polarized. Receptor-mediated endocytic uptake of fluorescent albumin and transferrin in 30:insH and R637X ciPTECs was significantly decreased, compared with normal ciPTECs, and could be further reduced by competition with 10-fold excess of unlabeled albumin and transferrin, whereas in the del132-241 ciPTEC, receptor-mediated endocytic uptake was abolished. Investigation of endosomal acidification by live-cell imaging of pHluorin-VAMP2 (vesicle-associated membrane protein-2), a pH-sensitive-GFP construct, revealed that the endosomal pH in normal and 30:insH ciPTECs was similar, whereas in del132-241 and R637X ciPTECs, it was significantly more alkaline, indicating defective acidification in these ciPTECs. The addition of bafilomycin-A1, a V-ATPase inhibitor, raised the pH significantly in all ciPTECs, demonstrating that the differences in acidification were not due to alterations in the V-ATPase, but instead to abnormalities of CLC-5. Thus, our studies, which have established human Dent disease ciPTECs that will facilitate studies of mechanisms in renal reabsorption, demonstrate that Dent disease-causing CLC-5 mutations have differing effects on endosomal acidification and receptor-mediated endocytosis that may not be coupled.
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PMID:Receptor-mediated endocytosis and endosomal acidification is impaired in proximal tubule epithelial cells of Dent disease patients. 2357 77

Congenital distal renal tubular acidosis (RTA) from mutations of the B1 subunit of V-ATPase is considered an autosomal recessive disease. We analyzed a distal RTA kindred with a truncation mutation of B1 (p.Phe468fsX487) previously shown to have failure of assembly into the V1 domain of V-ATPase. All heterozygous carriers in this kindred have normal plasma HCO3- concentrations and thus evaded the diagnosis of RTA. However, inappropriately high urine pH, hypocitraturia, and hypercalciuria were present either individually or in combination in the heterozygotes at baseline. Two of the heterozygotes studied also had inappropriate urinary acidification with acute ammonium chloride loading and an impaired urine-blood Pco2 gradient during bicarbonaturia, indicating the presence of a H+ gradient and flux defects. In normal human renal papillae, wild-type B1 is located primarily on the plasma membrane, but papilla from one of the heterozygote who had kidney stones but not nephrocalcinosis showed B1 in both the plasma membrane as well as diffuse intracellular staining. Titration of increasing amounts of the mutant B1 subunit did not exhibit negative dominance over the expression, cellular distribution, or H+ pump activity of wild-type B1 in mammalian human embryonic kidney-293 cells and in V-ATPase-deficient Saccharomyces cerevisiae. This is the first demonstration of renal acidification defects and nephrolithiasis in heterozygous carriers of a mutant B1 subunit that cannot be attributable to negative dominance. We propose that heterozygosity may lead to mild real acidification defects due to haploinsufficiency. B1 heterozygosity should be considered in patients with calcium nephrolithiasis and urinary abnormalities such as alkalinuria or hypocitraturia.
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PMID:Incomplete distal renal tubular acidosis from a heterozygous mutation of the V-ATPase B1 subunit. 2516 82

Distal renal tubular acidosis (dRTA) is a tubular disorder with a primary defect of urinary acidification and acid excretion in the collecting duct system. Consequently, patients develop hyperchloremic metabolic acidosis with an inappropriately alkaline urine. Inherited forms of dRTA are due to mutations in at least three distinct genes: SLC4A1, ATP6V1B1, ATP6V0A4. Mutations in SLC4A1-(AE1) are inherited either in an autosomal dominant manner or in a recessive one. ATP6V1B and ATP6V0A4 mutations affect two different subunits of the vacuolar H+-ATPase proton-pump, the B1 and a4 subunits, and are inherited in an autosomal recessive manner. Clinical manifestations of inherited forms of dRTA usually occur during infancy or childhood. However, heterozygous carriers of ATP6V1B1 and ATP6V0A4 mutations may have a higher risk of developing nephrolithiasis and nephrocalcinosis in adulthood, respectively. In full forms of dRTA, patients may present with mild clinical symptoms, such as mild metabolic acidosis and incidental detection of kidney stones, as well as with more severe manifestations such as failure to thrive, severe metabolic acidosis, and nephrocalcinosis. Progressive sensorineural hearing loss develops in the majority of patients with recessive dRTA (ATP6V1B1 and ATP6V0A4 mutations). Some patients with recessive dRTA may also develop abnormal widening of the vestibular aqueduct. This review will discuss our current understanding of the pathophysiology of inherited forms of dRTA, diagnosis and prognosis of patients, and therapy.
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PMID:Pathophysiology, diagnosis and treatment of inherited distal renal tubular acidosis. 2899 37

Organotin compounds (OTs) are synthetic persistent organometallic xenobiotics widely used in several commercial applications. They exert well-described harmful effects in brain, liver, adipose tissue, and reproductive organs, as they are endocrine-disrupting chemicals (EDCs), but the effects in the kidneys are less known. The kidneys are especially vulnerable to environmental contaminants because they are a metabolizing site of xenobiotics, therefore, pollutants can accumulate in renal tissue, leading to impaired renal function and to several renal abnormalities. Individuals chronically exposed to OTs present a threefold increase in the prevalence of kidney stones. These compounds can directly inhibit H+/K+-ATPase in renal intercalated cells, resulting in hypokalemia, renal tubular acidity, and increased urinary pH, which is a known risk factor for kidney stones formation. OTs effects are not only limited to induce nephrolithiasis, its nephrotoxicity is also due to increased reactive oxygen species (ROS). This increase leads to lipid peroxidation, abnormal cellular function, and cell death. Combined, the enzymatic and non-enzymatic antioxidant defense systems become deficient and there is a consequent uncontrolled generation of ROS that culminates in renal tissue damage. Still, few epidemiological and experimental studies have reported renal impact correlated to OTs exposure. This lack of investigation of the complete effect of OTs in renal function and structure led us to perform this review reporting the main researches about this subject.
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PMID:Organotin Compounds Toxicity: Focus on Kidney. 2987 23

Primary distal renal tubular acidosis (dRTA) is a rare genetic disorder caused by impaired distal acidification due to a failure of type A intercalated cells (A-ICs) in the collecting tubule. dRTA is characterized by persistent hyperchloremia, a normal plasma anion gap, and the inability to maximally lower urinary pH in the presence of systemic metabolic acidosis. Common clinical features of dRTA include vomiting, failure to thrive, polyuria, hypercalciuria, hypocitraturia, nephrocalcinosis, nephrolithiasis, growth delay, and rickets. Mutations in genes encoding three distinct transport proteins in A-ICs have been identified as causes of dRTA, including the B1/ATP6V1B1 and a4/ATP6V0A4 subunits of the vacuolar-type H+-ATPase (H+-ATPase) and the chloride-bicarbonate exchanger AE1/SLC4A1. Homozygous or compound heterozygous mutations in ATP6V1B1 and ATP6V0A4 lead to autosomal recessive (AR) dRTA. dRTA caused by SLC4A1 mutations can occur with either autosomal dominant or AR transmission. Red blood cell abnormalities have been associated with AR dRTA due to SLC4A1 mutations, including hereditary spherocytosis, Southeast Asia ovalocytosis, and others. Some patients with dRTA exhibit atypical clinical features, including transient and reversible proximal tubular dysfunction and hyperammonemia. Incomplete dRTA presents with inadequate urinary acidification, but without spontaneous metabolic acidosis and recurrent urinary stones. Heterozygous mutations in the AE1 or H+-ATPase genes have recently been reported in patients with incomplete dRTA. Early and sufficient doses of alkali treatment are needed for patients with dRTA. Normalized serum bicarbonate, urinary calcium excretion, urinary low-molecular-weight protein levels, and growth rate are good markers of adherence to and/or efficacy of treatment. The prognosis of dRTA is generally good in patients with appropriate treatment. However, recent studies showed an increased frequency of chronic kidney disease (CKD) in patients with dRTA during long-term follow-up. The precise pathogenic mechanisms of CKD in patients with dRTA are unknown.
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PMID:Improving outcomes for patients with distal renal tubular acidosis: recent advances and challenges ahead. 3058 51

Distal renal tubular acidosis is a defect of acidification of urine in distal tubule. Full-blown form is characterized by polyuria, growth deficiency, nephrolithiasis or nephrocalcinosis. Mutations in genes encoding Cl-/HCO3 - exchanger (autosomal dominant) or H+-ATPase (autosomal recessive) are the most frequent in children.
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PMID:[Accidentally diagnosed distal renal tubular acidosis with nephrocalcinosis - a case report]. 3091 26

Distal renal tubular acidosis (dRTA) is characterized by metabolic acidosis due to uric acid dysfunction. The aim of this study was to demonstrate the genetic diagnosis of Chinese children with dRTA by whole-exome sequencing. From Jan. 2010 to Sept. 2015, 16 children with dRTA were recruited to investigate the possibility of genetic diagnosis and to examine any genotype-phenotype relationships in these patients. Sanger sequencing was used to confirm mutations identified by whole-exome sequencing. Clinical and biological features in the patients included hyperchloremic metabolic acidosis, impaired growth, hypokalemia, nephrocalcinosis, nephrolithiasis, hypercalciuria, hypocitraturia, and rickets or osteomalacia. Seventeen mutations in the solute carrier family 4 member 1 (SLC4A1), ATPase H+ transporting V0 subunit a4 (ATP6V0A4), ATPase H+ transporting V1 subunit B1 (ATP6V1B1), WNK lysine deficient protein kinase 1 (WNK1) and the claudin 16 (CLDN16) were identified in 15 patients, and 14 of these mutations are novel. Only 1 patient was negative for any mutations. Our results demonstrate the existence of SLC4A1, ATP6V1B1, ATP6V0A4, WNK1 and CLDN16 mutations in Chinese children with dRTA and indicate that compound heterozygosity at 2 or more different but related genes can be responsible for its pathogenesis. This study also indicates that whole-exome sequencing is a labor and cost-effective means of analyzing dRTA-associated genes.
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PMID:Clinical features and genetic findings in Chinese children with distal renal tubular acidosis. 3194 30


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