In: American Journal of Physiology: Renal Physiology, 2008, vol. 294, no. 6, p. F1373-F1380
ROMK-deficient (Romk–/–) mice exhibit polyuria, natriuresis, and kaliuresis similar to individuals with type II Bartter's form of hyperprostaglandin E syndrome (HPS; antenatal Bartter's syndrome). In the present study, we utilized both metabolic and clearance studies to define the contributions of specific distal nephron segments to the renal salt wasting in these mice. The...
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In: Proceedings of the National Academy of Sciences of the United States of America, 2007, vol. 104, no. 37, p. 14849-14854
The distal convoluted tubule (DCT) plays an essential role in the reabsorption of NaCl by the kidney, a process that can be inhibited by thiazide diuretics. Parvalbumin (PV), a Ca²⁺-binding protein that plays a role in muscle fibers and neurons, is selectively expressed in the DCT, where its role remains unknown. We therefore investigated the renal phenotype of PV knockout mice...
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In: Histochemistry and Cell Biology, 2007, vol. 127, no. 4, p. 389-398
The renal collecting system (CS) is composed of segment-specific (SS) and intercalated (IC) cells. The latter comprise at least two subtypes (type A and non-type A IC). The origin and maintenance of cellular heterogeneity in the CS is unclear. Among other hypotheses, it was proposed that one subtype of IC cells represents a stem cell population from which all cell types in the CS may arise....
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In: Journal of the American Society of Nephrology, 2006, vol. 17, p. 1264-1274
The activity of the epithelial sodium (Na⁺) channel (ENaC) in the aldosterone-sensitive distal nephron (ASDN) needs to be tightly regulated to match urinary Na⁺ excretion with dietary Na⁺ intake. The ubiquitin-protein ligase Nedd4-2, which in vitro interacts with ENaC subunits and reduces ENaC cell surface abundance and activity by ubiquitylation of the channel, may participate in...
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In: Journal of Biological Chemistry, 2005, vol. 280, no. 46, p. 38264-38270
Activation of the mitogen-activated protein (MAP) kinase cascade by progesterone in Xenopus oocytes leads to a marked down-regulation of activity of the amiloride-sensitive epithelial sodium channel (ENaC). Here we have studied the signaling pathways involved in progesterone effect on ENaC activity. We demonstrate that: (i) the truncation of the C termini of the αβγENaC subunits...
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In: Journal of the American Society of Nephrology, 2005, vol. 16, p. 3642
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In: Journal of the American Society of Nephrology, 2005, vol. 16, p. 3175
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In: Journal of the American Society of Nephrology, 2005, vol. 16, p. 2279
Aldosterone plays a central role in Na⁺ homeostasis by controlling Na⁺ reabsorption in the aldosterone-sensitive distal nephron involving the epithelial Na⁺ channel (ENaC). Part of the effects of aldosterone is mediated by serum and glucocorticoid-induced kinase 1 (Sgk1), a Ser/Thr kinase whose expression is rapidly induced by aldosterone and that increases in heterologous expression...
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In: The Journal of Clinical Investigation, 2005, vol. 115(6), p. 1651
Thiazide diuretics enhance renal Na⁺ excretion by blocking the Na⁺-Cl⁻ cotransporter (NCC), and mutations in NCC result in Gitelman syndrome. The mechanisms underlying the accompanying hypocalciuria and hypomagnesemia remain debated. Here, we show that enhanced passive Ca²⁺ transport in the proximal tubule rather than active Ca²⁺ transport in distal convolution explains...
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In: Histochemistry and Cell Biology, 2005, vol. 123(4-5), p. 335
Fibrosis is considered as a central factor in the loss of renal function in chronic kidney diseases. The origin of fibroblasts and myofibroblasts that accumulate in the interstitium of the diseased kidney is still a matter of debate. It has been shown that accumulation of myofibroblasts in inflamed and fibrotic kidneys is associated with upregulation of fibroblast-specific protein 1 (FSP1,...
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