Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P41181 (collecting duct)
 5,183 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The expression of polysialic acid (PSA) and the neural cell adhesion molecule (N-CAM) during the embryonic development of rat kidney was investigated using immunocytochemistry and immunoblotting. A monoclonal antibody (mAb 735), which recognised only long chain PSA, and polyclonal antibodies specific for N-CAM were employed. At the earliest stages of metanephros formation, PSA and N-CAM immunostaining was found in both embryonic anlagen, namely the uretic bud and the metanephrogenic mesenchyme. Reactivity in uretic bud derivatives declined during embryonic development and was generally absent in the collecting duct system by embryonic day 18 (E18). Uninduced metanephrogenic mesenchyme was immunostained throughout development while induced mesenchymal cells showed greatly increased PSA and N-CAM immunoreactivity during their transformation into epithelium. This staining declined rapidly as nephrons differentiated. These processes were preceded by sorting of PSA and N-CAM to the basolateral plasma membrane. Similar N-CAM and PSA patterns were observed in mesonephros development. In adult kidney parenchyma both PSA and N-CAM were undetectable. Immunoblotting of samples of embryonic kidney with mAb 735 revealed a broad band ranging from 140 to greater than 200 x 10(3) Mr. N-CAM antibodies revealed reactivity in a band of 140 x 10(3) Mr after removal of PSA by endoneuraminidase treatment. Expression of N-CAM and PSA in both embryonic anlagen indicates that neither molecular species acts primarily as an inductive signal. These molecules were localised in areas where changes in cell adhesion during organogenesis might be important and thus may be involved in the grouping of developing cells.
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PMID:Polysialic acid and N-CAM localisation in embryonic rat kidney: mesenchymal and epithelial elements show different patterns of expression. 208 29

Eight cases of congenital mesoblastic nephroma (CMN) were examined. Three CMNs were of the classical (typical) variant, two were cellular (atypical), and three showed a mixed pattern. A panel of nephron segment-specific tubular epithelial markers (the lectins Tetragonolobus purpureas, Phaseolus vulgaris erythroagglutinin, and Arachis hypogaea and antibodies to epithelial membrane antigen, cytokeratin, and Tamm-Horsfall protein) were used to differentiate epithelial structures within the tumor. Antibodies against vimentin, desmin, and muscle-specific actin were used as mesenchymal markers. A monoclonal antibody to the long (embryonic) form of polysialic acid (PSA) on the neural cell adhesion molecule was used as a putative renal oncodevelopmental marker. An antibody to proliferating cell nuclear antigen also was applied, which revealed increased proliferative rate in cellular CMNs. In addition to clearly entrapped native renal tubules, CMNs contain tubular structures with immature, dysplastic epithelium and occasional epithelial cell clusters embedded deep within the tumor. These immature tubules and clusters express distal nephron, including collecting duct markers and, occasionally, vimentin and PSA. We propose that these primitive tubules and epithelial structures may originate from the ureteric bud. An epithelial differentiation of the tumor cells also is possible. In one pure cellular CMN and two mixed CMNs the cellular component showed diffuse staining for PSA. The PSA (neural cell adhesion molecule) expression of the cellular component suggests that CMN may originate from the uninduced nephrogenic mesenchyme.
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PMID:Congenital mesoblastic nephroma: an immunohistochemical and lectin study. 838 53

Type IV collagenases matrix metalloproteinase-2 (MMP2) and MMP9 and their related proteins, MT1-MMP, tissue inhibitor of metalloproteinases 1 (TIMP1), TIMP2, and TIMP3, are expressed during kidney morphogenesis and nephrogenesis, but the renal ontogeny of these proteins is only partially known, and their persistence in the adult remains controversial. Their expression was analyzed from early metanephric stages to adulthood by Western blot semiquantitative analysis; laser confocal microscopy of whole-mount kidneys; and a two-step immunoperoxidase labeling procedure using specific markers of proximal tubule (megalin), ascending limb of Henle's loop (Tamm Horsfall protein), and collecting duct (Dolichos biflorus agglutinin lectin). By Western blot, all antigens were detected at day 11.5, peaked at day 16.5, and persisted in the adult at lower levels, although MMP2 was less modulated. All antigens were expressed in metanephric mesenchyme at embryonic day 11.5 and became concentrated in neural cell adhesion molecule-positive-induced mesenchymal cells at day 12.5. Only MT1-MMP and to a lesser extent MMP2 were detected in the ureter bud. At day 16.5, all antigens predominated in the cytoplasm of the proximal tubule, except TIMP1, which was mostly expressed in the ascending limb of Henle's loop and distal tubule. During tubule segmentation, components of the type IV collagenase system showed both spatial and temporal regulation. The distribution of gelatinases was not strictly superimposable to that of their natural inhibitors TIMP, especially for MMP9 and TIMP1. All components persisted in specific segments of the adult renal tubule, where MMP9, MMP2, and MT1-MMP showed an apical expression, suggesting that substrates for these enzymes should be in the tubule lumen or in the apical cell domain and not in the extracellular matrix. These results suggest that a regulated balance of gelatinase activity is required during kidney organogenesis and that gelatinases continue to play a role in adult renal tubule physiology.
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PMID:Expression of the type IV collagenase system during mouse kidney development and tubule segmentation. 1167 12