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Query: UNIPROT:P41181 (collecting duct)
 5,183 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recent studies have suggested that crescents are primarily of monocytic origin and that epithelial cells are a minor factor in their composition. Frozen sections of renal biopsies from 11 cases of crescentic glomerulonephritis (CGN) and 5 controls (2 acute interstitial nephritis, 1 focal glomerulosclerosis, 1 benign recurrent hematuria, 1 normal kidney) were stained for intracellular cytokeratin (CK) with a mouse monoclonal anti-CK antiserum (PKK1) and nonspecific esterase (NSE) activity. Indirect immunofluorescence with PKK1 antiserum showed that in all biopsies there was positive staining of collecting duct and proximal and distal tubular epithelium but no reactions in blood vessels or interstitium. In control case glomeruli there was no staining of the tuft, including the visceral epithelium. In all cases some parietal epithelium was CK-positive. In 4 CGN biopsies the majority of the crescents showed cytoplasmic staining for CK in more than 50% of the crescent cells. In 2 cases most crescents contained between 10-50% CK-positive cells, whereas in 5 biopsies little or no CK was present in the majority of crescents. In all but one CGN case the majority of crescents contained fewer than 30% NSE-positive cells (monocytes). Electron microscopy demonstrated intermediate filaments in many crescent cells and scattered desmosomes within crescents. The results indicate that epithelial cells, probably of parietal epithelial origin, contribute significantly to crescent formation.
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PMID:Histogenesis of glomerular crescents. Immunohistochemical demonstration of cytokeratin in crescent cells. 241 Nov 41

We have used three fluorescent probes to label acid-base transporting cells with specific physiological properties in the rabbit collecting duct. Rhodamine albumin identified cells active in luminal endocytosis; rhodamine peanut agglutinin (PNA) identified cells with apical surface PNA ligands; and 6-carboxyfluorescein (6-CF) diacetate identified cells with alkaline pH or acetazolamide-sensitive esterase activity. More than 90% of all cells identified by PNA or rhodamine albumin selectively concentrated 6-CF. Axial heterogeneity of the identified cells was clearly evident along the collecting duct. In the midcortical collecting duct the predominant labeled cell (108 +/- 15/mm) was positive for PNA and 6-CF. These cells were less prevalent (69 +/- 10/mm) in inner cortical collecting ducts and absent from the outer medullary collecting duct. Cells that labeled only with 6-CF (with no detectable luminal endocytosis or PNA binding) showed the opposite distribution. They were the predominant identified cell in the inner stripe of the outer medulla (126 +/- 20/mm), and were less common in the cortical collecting duct. Because the former segment secretes H+, it was likely that these cells were H+-secreting cells. We used excitation ratio microspectrofluorometry of 6-CF to measure cytosolic pH (pHi approximately 7.2) and found evidence for a basolateral DIDS-sensitive Cl- -HCO3- exchanger and a Na+-independent luminal H+ pump. The previously described endocytic H+-secreting cell was seen at its highest concentration in the outer stripe (39 +/- 6/mm). Finally, 5-10% of identified cells did not stain selectively with 6-CF in cortical collecting ducts (solely endocytic or PNA binding). The function of these latter types could not be established. These studies suggest that the distribution and number of these populations of cells may determine the direction and magnitude of H+ transport along the collecting duct.
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PMID:Fluorescent characterization of collecting duct cells: a second H+-secreting type. 246 Oct 95

Cell culture conditions were devised that selectively supported growth of 13 or 14 gestation day F344 rat ureteric bud, the renal collecting duct anlagen. These same conditions also inhibited the growth of metanephrogenic mesenchyme, precursor of structures proximal to the duct. Isolated buds were cultured in Ham's F12 medium supplemented with epidermal growth factor, selenium, insulin, hydrocortisone, prostaglandin E1, transferrin, and triiodothyronine; fetal bovine serum (1%) was required for continuous propagation. Cultured cells were epithelial in morphology and formed domes. By electron microscopy, many structural characteristics of highly differentiated cells were evident: numerous mitochondria, Golgi apparatus, extensive endoplasmic reticulum, an occasional cilium, intracytoplasmic filaments, polarized formation of microvilli, and gap junctions. Histochemistry revealed considerable functional differentiation as well. Cultured bud cells, adult collecting duct, and fetal duct anlagen were positive for acid phosphatase, membrane-localized ATPase, and nonspecific esterase. Bud cells and fetal duct anlagen expressed high levels of gamma-glutamyl transpeptidase activity while adult collecting duct exhibited slight activity. In addition, immunocytochemical observation of intermediate filament expression revealed the presence of epithelial cytokeratins but absence of mesenchymal vimentin in cultured bud cells and fetal and adult collecting ducts. These results indicate that the culture conditions described can maintain the partially differentiated fetal collecting duct anlagen in a state consistent with its embryonal derivation, and therefore may be useful in culture studies of renal differentiation.
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PMID:Selective growth in culture of fetal rat renal collecting duct anlagen. Morphologic and biochemical characterization. 286 2

Glycerophosphocholine (GPC) is an osmoprotective compatible and counteracting organic osmolyte that accumulates in renal inner medullary cells in response to high NaCl and urea. We previously found that high NaCl increases GPC in renal [Madin-Darby canine kidney (MDCK)] cells. The GPC is derived from phosphatidylcholine, catalyzed by a phospholipase that was not identified at that time. Neuropathy target esterase (NTE) was recently shown to be a phospholipase B that catalyzes production of GPC from phosphatidylcholine. The purpose of the present study was to test whether NTE contributes to the high NaCl-induced increase of GPC synthesis in renal cells. We find that in mouse inner medullary collecting duct cells, high NaCl increases NTE mRNA within 8 h and NTE protein within 16 h. Diisopropyl fluorophosphate, which inhibits NTE esterase activity, reduces GPC accumulation, as does an siRNA that specifically reduces NTE protein abundance. The 20-h half-life of NTE mRNA is unaffected by high NaCl. TonEBP/OREBP is a transcription factor that is activated by high NaCl. Knockdown of TonEBP/OREBP by a specific siRNA inhibits the high NaCl-induced increase of NTE mRNA. Further, the lower renal inner medullary interstitial NaCl concentration that occurs chronically in ClCK1-/- mice and acutely in normal mice given furosemide is associated with lower NTE mRNA and protein. We conclude that high NaCl increases transcription of NTE, likely mediated by TonEBP/OREBP, and that the resultant increase of NTE expression contributes to increased production and accumulation of GPC in mammalian renal cells in tissue culture and in vivo.
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PMID:Neuropathy target esterase catalyzes osmoprotective renal synthesis of glycerophosphocholine in response to high NaCl. 1701 41