Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01185 (vasopressin)
 23,126 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Autosomal dominant polycystic kidney disease (ADPKD) gene products polycystin-1 (PC1) and polycystin-2 (PC2) colocalize in the apical monocilia of renal epithelial cells. Mouse and human renal cells without PC1 protein show impaired ciliary mechanosensation, and this impairment has been proposed to promote cystogenesis. However, most cyst epithelia of human ADPKD kidneys appear to express full-length PC1 and PC2 in normal or increased abundance. We show that confluent primary ADPKD cyst cells with the novel PC1 mutation DeltaL2433 and with normal abundance of PC1 and PC2 polypeptides lack ciliary PC1 and often lack ciliary PC2, whereas PC1 and PC2 are both present in cilia of confluent normal human kidney (NK) epithelial cells in primary culture. Confluent NK cells respond to shear stress with transient increases in cytoplasmic Ca(2+) concentration ([Ca(2+)](i)), dependent on both extracellular Ca(2+) and release from intracellular stores. In contrast, ADPKD cyst cells lack flow-sensitive [Ca(2+)](i) signaling and exhibit reduced endoplasmic reticulum Ca(2+) stores and store-depletion-operated Ca(2+) entry but retain near-normal [Ca(2+)](i) responses to ANG II and to vasopressin. Expression of wild-type and mutant CD16.7-PKD1(115-226) fusion proteins reveals within the COOH-terminal 112 amino acids of PC1 a coiled-coil domain-independent ciliary localization signal. However, the coiled-coil domain is required for CD16.7-PKD1(115-226) expression to accelerate decay of the flow-induced Ca(2+) signal in NK cells. These data provide evidence for ciliary dysfunction and polycystin mislocalization in human ADPKD cells with normal levels of PC1.
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PMID:Human ADPKD primary cyst epithelial cells with a novel, single codon deletion in the PKD1 gene exhibit defective ciliary polycystin localization and loss of flow-induced Ca2+ signaling. 1709 Jul 81

Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic disease that causes kidney failure and accounts for 10% of all patients who are on renal replacement therapy. However, the marked phenotypic variation between patients who carry the same PKD1 or PKD2 mutation suggests that nonallelic factors may have a greater influence on the cystic phenotype. Endothelin-1 (ET-1) transgenic mice have been reported to develop profound renal cystic disease and interstitial fibrosis without hypertension. The hypothesis that ET-1 acts as a modifying factor for cystic disease progression was tested in an orthologous mouse model of ADPKD (Pkd2(WS25/-)). Four experimental groups (n = 8 to 11) were treated from 5 to 16 wk of age with the highly selective orally active receptor antagonists ABT-627 (ETA) and A-192621 (ETB) singly or in combination. Unexpected, ETB blockade led to accelerated cystic kidney disease. Of significance, this was associated with a reduction in urine volume and sodium excretion and increases in urine osmolarity and renal cAMP and ET-1 concentrations. The deleterious effect of chronic ETB blockade was neutralized by simultaneous ETA blockade. ETA blockade alone resulted in a significant increase in tubular cell proliferation but did not alter the cystic phenotype. It is concluded that the balance between ETA and ETB signaling is critical for maintaining tubular structure and function in the cystic kidney. These results implicate ET, acting via vasopressin-dependent and independent pathways, as a major modifying factor for cystic disease progression in human ADPKD.
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PMID:Endothelin B receptor blockade accelerates disease progression in a murine model of autosomal dominant polycystic kidney disease. 1720 12

Polycystic kidney diseases (autosomal dominant and autosomal recessive) are progressive renal tubular cystic diseases, which are characterised by cyst expansion and loss of normal kidney structure and function. Autosomal dominant polycystic kidney disease (ADPKD) is the most common life- threatening, hereditary disease. ADPKD is more prevalent than Huntington's disease, haemophilia, sickle cell disease, cystic fibrosis, myotonic dystrophy and Down's syndrome combined. Early diagnosis and treatment of hypertension with inhibitors of the renin-angiotensin-aldosterone system (RAAS) and its potential protective effect on left ventricular hypertrophy has been one of the major therapeutic goals to decrease cardiac complications and contribute to improved prognosis of the disease. Advances in the understanding of the genetics, molecular biology and pathophysiology of the disease are likely to facilitate the improvement of treatments for these diseases. Developments in describing the role of intracellular calcium ([Ca(2+)](i)) and its correlation with cellular signalling systems, Ras/Raf/mitogen extracellular kinase (MEK)/extracellular signal-regulated protein kinase (ERK), and interaction of these pathways with cyclic adenosine monophosphate (cAMP) levels, provide new insights on treatment strategies. Blocking the vasopressin V(2) receptor, a major adenylyl cyclase agonist, demonstrated significant improvements in inhibiting cytogenesis in animal models. Because of activation of the mammalian target of rapamycin (mTOR) pathway, the use of sirolimus (rapamycin) an mTOR inhibitor, markedly reduced cyst formation and decreased polycystic kidney size in several animal models. Caspase inhibitors have been shown to decrease cytogenesis and renal failure in rats with cystic disease. Cystic fluid secretion results in cyst enlargement and somatostatin analogues have been shown to decrease renal cyst progression in patients with ADPKD. The safety and efficacy of these classes of drugs provide potential interventions for experimental and clinical trials.
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PMID:Potential pharmacological interventions in polycystic kidney disease. 1803 88

Autosomal dominant polycystic kidney disease, a leading cause of end-stage renal disease in adults, is characterized by progressive focal cyst formation in the kidney. Embryonic lethality of Pkd1-targeted mice limits the use of these mice. Here we developed a floxed allele of Pkd1 exons 2-6. Global deletion mutants developed polyhydramnios, hydrops fetalis, polycystic kidney and pancreatic disease. Somatic Pkd1 inactivation in the kidney was achieved by crossing Pkd1(flox) mice with transgenic mice expressing Cre controlled by a gamma-glutamyltranspeptidase promoter. These mutants developed cysts in both proximal and distal nephron segments and survived for about 4 weeks. Somatic loss of heterozygosity was shown in a reporter mouse strain to cause cystogenesis. Some cysts in young mice are positive for multiple tubular markers and a mesenchymal marker, suggesting a delay in tubular epithelial differentiation. A higher cell proliferation rate was observed in distal nephron segments probably accounting for the faster growth rate of distal cysts. Although we observed an overall increase in apoptosis in cystic kidneys, there was no difference between proximal or distal nephron segments. We also found increased cyclic AMP, aquaporin 2 and vasopressin type 2 receptor mRNA levels, and apical membrane translocation of aquaporin 2 in cystic kidneys, all of which may contribute to the differential cyst growth rate observed. The accelerated polycystic kidney phenotype of these mice provides an excellent model for studying molecular pathways of cystogenesis and to test therapeutic strategies.
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PMID:A mouse model for polycystic kidney disease through a somatic in-frame deletion in the 5' end of Pkd1. 1838 65

Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common hereditary disorders. It accounts for 6% of the incidence of end-stage renal disease in Europe. Over the last decade, knowledge of the pathology underlying this disease has increased rapidly. Attributing important roles to tubular cell ciliary functioning, cell proliferation and fluid secretion, subsequent alterations in levels of intracellular calcium, adenosine 3',5'-cyclic monophosphate (cAMP) and activation of a variety of cellular kinases, including mammalian target of rapamycin (mTOR), has laid out the foundations for development of potentially effective treatments. In this editorial, the possible therapeutic roles for vasopressin antagonists, rapamycin, somatostatin and roscovitine are discussed. Clinical trials have been started to investigate the efficacy and safety of these agents for treating ADPKD in humans.
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PMID:Better understanding of ADPKD results in potential new treatment options: ready for the cure? 1844 6

Autosomal dominant polycystic kidney disease (ADPKD) is a common hereditary disease associated with progressive renal failure. Although cyst growth and compression of surrounding tissue may account for some loss of renal tissue, the other factors contributing to the progressive renal failure in patients with ADPKD are incompletely understood. Here, we report that secreted frizzled-related protein 4 (sFRP4) is upregulated in human ADPKD and in four different animal models of PKD, suggesting that sFRP4 expression is triggered by a common mechanism that underlies cyst formation. Cyst fluid from ADPKD kidneys activated the sFRP4 promoter and induced production of sFRP4 protein in renal tubular epithelial cell lines. Antagonism of the vasopressin 2 receptor blocked both promoter activity and tubular sFRP4 expression. In addition, sFRP4 selectively influenced members of the canonical Wnt signaling cascade and promoted cystogenesis of the zebrafish pronephros. sFRP4 was detected in the urine of both patients and animals with PKD, suggesting that sFRP4 may be a potential biomarker for monitoring the progression of ADPKD. Taken together, these observations suggest a potential role for SFRP4 in the pathogenesis of ADPKD.
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PMID:Increased expression of secreted frizzled-related protein 4 in polycystic kidneys. 1894 44

Vasopressin (AVP) is a hormone with antidiuretic properties that is also involved in cellular proliferation of breast, pulmonary, and pancreatic neoplasias, attributable to the interaction with specific receptors, among which is the V2-R. Using a culture model of CAKI-2 and A498 cancer cells, our study aimed to verify if renal carcinoma cells also express V2-R and whether receptor activation modulates their proliferation. Immunofluorescence and RT-PCR showed that both CAKI-2 and A498 cells effectively synthesize and express the V2-R. Administration of the vasopressin analogue DDAVP induced an evident growth in both CAKI-2 and A498 cell lines. However, this proliferative effect was completely avoided by the preventive addition of the V2-R antagonist SR121463B (satavaptan). Our study shows for the first time that renal cancer may effectively synthesize and express the V2-R. Furthermore, AVP exerts in vitro a proliferative effect by acting on this receptor, as the selective V2-R blockage is able to completely prevent the cellular growth. A validation of these findings with in vivo models is required to ascertain if the eventual presence of V2-R could influence the aggressiveness of human renal neoplasias. From this point of view, a new, interesting therapeutical application of V2-R antagonists in the treatment of renal cancer could also be proposed, similar to that successfully described in the treatment of autosomal polycystic kidney disease (ADPKD).
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PMID:Aquaretic inhibits renal cancer proliferation: Role of vasopressin receptor-2 (V2-R). 1921 6

Autosomal dominant polycystic disease (ADPKD) is an inherited disorder characterized by the development within renal tubules of innumerable cysts that progressively expand to cause renal insufficiency. Tubule cell proliferation and transepithelial fluid secretion combine to enlarge renal cysts, and 3'-5'-cyclic adenosine monophosphate (cAMP) stimulates that growth. The antidiuretic hormone, arginine vasopressin (AVP), operates continuously in ADPKD patients to stimulate the formation of cAMP, thereby contributing to cyst and kidney enlargement and renal dysfunction. Studies in animal models of ADPKD provide convincing evidence that blocking the action of AVP dramatically ameliorates the disease process. In the current analysis, the authors reason that increasing the amount of solute-free water drunk evenly throughout the day in patients with ADPKD and normal renal function will decrease plasma AVP concentrations and mitigate the action of cAMP on the renal cysts. Potential pitfalls of increasing fluid intake in ADPKD patients are considered, and suggestions for how physicians may prudently implement this therapy are offered.
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PMID:A case for water in the treatment of polycystic kidney disease. 1944 27

Orskov and colleagues demonstrate the impact of birth weight on the mean age of end-stage renal disease (ESRD) in a large Danish ADPKD cohort. Each kilogram of birth weight extended the mean age of ESRD onset by 1.7 years. Placental insufficiency, activation of the renin-angiotensin-aldosterone system, increased fetal vasopressin levels, compensatory increases in insulin like growth factor-I, and a reduction in total nephron number may all contribute to this observation. Collectively, these changes result in an accelerated pace of cyst formation and expansion, and an inability to maintain glomerular hyperfiltration during kidney expansion which results in a more rapid progression to ESRD. Therefore the intrauterine environment may play a critical role in disease severity in ADPKD.
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PMID:The fetal environment: a critical phase that determines future renal outcomes in autosomal dominant polycystic kidney disease. 2229 78

Autosomal dominant polycystic kidney disease (ADPKD) is associated with a urine-concentrating defect attributed to renal cystic changes. As PKD genes are expressed in the brain, altered central release of arginine vasopressin could also play a role. In order to help determine this we measured central and nephrogenic components of osmoregulation in 10 adults and 10 children with ADPKD, all with normal renal function, and compared them to 20 age- and gender-matched controls. Overnight water deprivation caused a lower rise in urine osmolality in the patients with ADPKD than controls, reflecting an impaired release of vasopressin and a peripheral defect in the patients. The reactivity of plasma vasopressin to water deprivation, as found in controls, was blunted in the patients with the latter showing lower urine osmolality for the same range of plasma vasopressin. The maximal urine osmolality correlated negatively with total kidney volume. Defective osmoregulation was confirmed in the children with ADPKD but was unrelated to number of renal cysts or kidney size. Thus, patients with ADPKD have an early defect in osmoregulation, with a blunted release of arginine vasopressin. This reflects expression of polycystins in hypothalamic nuclei that synthesize vasopressin, and this should be considered when evaluating treatments targeting the vasopressin pathway in ADPKD.
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PMID:Autosomal dominant polycystic kidney disease is associated with central and nephrogenic defects in osmoregulation. 2312 16


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