Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.11 (CD10)
 9,792 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rat microglia in culture showed a high capacity to degrade neuropeptides compared with other glial cells. Leu-enkephalin was readily hydrolyzed to free tyrosine and Gly-Gly-Phe-Leu. Inhibition experiments and immunostaining revealed that aminopeptidase N (CD13) on the surface of microglia was responsible for enkephalin cleavage. Endopeptidase-24.11 ("enkephalinase"), angiotensin-converting enzyme, or carboxypeptidases could not be detected on microglia. Aminopeptidase N activity in microglia was considerably higher than in rat peripheral monocytes and macrophages, which both also exhibited low endopeptidase 24.11 activities. Activity of aminopeptidase N was upregulated by culture of microglia on astrocytes and down-regulated by exposure of microglia to lipopolysaccharide. The occurrence of aminopeptidase N on microglia is in line with the view that they originate from the monocytic lineage.
 ...
PMID:Enkephalin metabolism by microglial aminopeptidase N (CD13). 753 37

In this study an amphotropic retrovirus has been used to efficiently transduce normal human (NF) and scleroderma (systemic sclerosis; SSc) dermal fibroblasts (SScF) with a sequence encoding a temperature-sensitive mutant of the SV40 large T antigen (tsA58-U19). From the primary outgrowths of skin explants, cultures were generated whose growth was stringently temperature-dependent. When grown at a low, permissive temperature (35 degrees C), both normal and SSc-transduced cells continuously divided with similar doubling times, whereas at a high, nonpermissive temperature (39.5 degrees C), division of both the NF and SScF cells was rapidly arrested. These cells have been passaged more than 50 times, have the typical morphological appearance of fibroblasts, and have retained an anchorage-dependent phenotype. The transduced normal cells (tsT-NF) synthesized the matrix molecules collagen and fibronectin and expressed phenotypic antigens characteristic of their nontransduced counterparts, including MHC Class I, VLA beta 1 (CD29), Hermes 1 (CD44), VLA-4 alpha (CD49d), ICAM-1 (CD54) and LFA-3 (CD58) and the cell surface ectoenzymes neutral endopeptidase (CD10), aminopeptidase N (CD13), and dipeptidyl peptidase IV (CD26). Analysis of the transduced SSc fibroblasts (tsT-SScF) showed that these cells exhibited certain major features of the SSc pathology, notably the abnormally high synthesis of type I collagen, increased expression of ICAM-1, and depressed levels of CD26. Moreover, these phenotypic characteristics were retained even after prolonged culture in vitro. The tsT-SScF cells also retained their responsiveness to cytokines, since interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) both produced a marked increase in ICAM-1 expression. Our findings show that infection of SScF with the SV40 tsT antigen extends the life span of these cells and does not ablate their abnormal phenotypic and functional characteristics.
 ...
PMID:Scleroderma-derived human fibroblasts retain abnormal phenotypic and functional characteristics following retroviral transduction with the SV40 tsT antigen. 755 50

Inter- and intralobular mammary fibroblasts have been separated from normal human breast tissue and cultured to study the differential expression of ectoenzymes present within the stroma of the normal gland and associated with breast cancers. Specific ectoenzymes were identified by indirect immunofluorescence and quantified by flow cytometry and semi-quantitative PCR. A consistent difference was noted between the two fibroblast sub-populations at early passage in respect of dipeptidyl peptidase IV (DPP IV) and aminopeptidase N (APN) expression. Early passage intralobular fibroblasts were positive for APN but negative for DPP IV, as seen in the intact tissue. However, with continued sub-culture they gradually began to express DPP IV, until at later passages they became indistinguishable from the interlobular fibroblasts, which were APN and DPP IV-positive at all stages in culture, as they are in intact tissue. Neutral endopeptidase (NEP/CALLA/CD10) is not expressed by normal adult breast fibroblasts but is found in the stroma associated with over 60% of breast cancers. It was up-regulated in vitro on both inter- and intralobular fibroblasts, with final levels that were significantly (< 14 times) higher on the former in all pairs of preparations from individual donors analysed. This difference persisted with continued passage, and levels of the ectoenzyme and its messenger RNA were further up-regulated by hydrocortisone in both populations. These results demonstrate that phenotypically distinct cultures of human mammary fibroblast sub-populations can be used to study the regulation of these stromal ectoenzymes.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Ectoenzyme regulation by phenotypically distinct fibroblast sub-populations isolated from the human mammary gland. 787 58

The immunocytochemical distribution of three cell surface peptidases was investigated in samples of developing infant breast ranging in age from newborn to 9.5 months. We have previously demonstrated that in the adult breast these enzymes identify subpopulations of epithelial cells and fibroblasts. We therefore wished to address two questions: (a) At what stage in breast development can fibroblast subpopulations be identified, and (b) Is the distribution of these peptidases related to cellular differentiation and morphogenesis? At the histological level there was a cuff of stromal cells closely associated with the developing ductular and lobular structures. At all stages of ductular and lobular development the fibroblasts in this layer were consistently negative for dipeptidyl peptidase IV (DPP IV) and clearly distinguished from the fibroblasts in the surrounding matrix, some of which expressed DPP IV in an age-dependent manner. Within the infant breast aminopeptidase N (APN) was localised to luminal epithelial cells and all fibroblasts, whilst neutral endopeptidase (NEP) was specifically localised to myoepithelial cells. These results are considered in relation to the role of stromal-epithelial interactions during morphogenesis and the proposed function of these enzymes.
 ...
PMID:Immunolocalisation of cell surface peptidases in the developing human breast. 791 70

Both the sulphated and non-sulphated forms of cholecystokinin (CCK) octapeptide are susceptible to hydrolysis by the cell-surface peptidases endopeptidase-24.11 (NEP), angiotensin converting enzyme and aminopeptidase N (AP-N). Indirect studies have previously implicated an elastase-like serine endopeptidase in CCK metabolism in brain. We have therefore compared the hydrolysis of CCK, in both sulphated and non-sulphated forms by solubilized membrane preparations from the human astrocytoma clone D384 and the neuroblastoma line SH-SY5Y. Selective peptidase inhibitors were used to elucidate the principal activities involved in CCK metabolism. In the glial cell line the hydrolysis of cholecystokinin octapeptide (CCK-8), sulphated or non-sulphated, was inhibited predominantly by the NEP inhibitor, phosphoramidon (PR). In contrast, in the neuroblastoma line, angiotensin converting enzyme (ACE) was seen to play a major role in metabolism of CCK-8 with a lesser effect attributable to NEP but with some differences between sulphated and non-sulphated forms reflecting the preference of ACE for CCK-8ns. In neither cell line was a significant effect of the serine peptidase inhibitor Dip-F seen on CCK metabolism arguing against the presence of a putative CCK-degrading serine peptidase in these cell lines. Both NEP and ACE remain as candidates for inactivation of CCK at the cell surface.
 ...
PMID:Comparison of cholecystokinin metabolism by membrane preparations from the human astrocytoma clone D384 and the neuroblastoma line SH-SY5Y. 791 87

The cell-surface expression of endopeptidase-24.11 (EC 3.4.24.11) on Caco-2 cells cultured to confluency is markedly heterogeneous unlike that of dipeptidylpeptidase IV (EC 3.4.14.5). Here we have investigated the cell-surface expression of three other ectopeptidases: angiotensin converting enzyme (EC 3.4.15.1), aminopeptidase N (EC 3.4.11.2) and aminopeptidase W (EC 3.4.11.16). We show by indirect immunofluorescent staining that these three enzymes are present on the surface of some cells but not on others. However, these enzymes were detected in the majority of detergent-permeabilised Caco-2 cells indicating the presence of intracellular pools of these enzymes. This suggests that there may either be differential regulation of apical transport for these peptidases or that they recycle at different rates.
 ...
PMID:Mosaic expression of membrane peptidases by confluent cultures of Caco-2 cells. 809 58

A short treatment of dog renal brush-border membrane vesicles (BBMV) with sodium cholate, followed by dialysis of the detergent, reorients the polarity of H(+)-ATPase in the membrane and exposes its ATP binding sites to the extravesicular space, as previously shown with pig BBMV. In cholate-pretreated vesicles, the H(+)-ATPase remains fully active, but is inserted under the reversed polarity in sealed vesicles. A large spontaneous N-ethylmaleimide-sensitive ATPase activity is thus observed, as well as a steep intravesicular acidification upon external ATP addition, two findings absent in native vesicles. The ability of nitrate plus ATP to dissociate the hydrolytic subunits ot the proton pump in cholate-pretreated vesicles, but not in native vesicles, demonstrates that most of the ATP binding subunits are accessible to ATP following cholate treatment. The sensitivity of the cytoplasmic domain of the H(+)-ATP activity to trypsin also confirms the reorientation of the enzyme in cholate-pretreated vesicles. The H(+)-ATPase and alkaline phosphatase remain largely associated with the membranes after the treatment with cholate, but gamma-glutamyltranspeptidase, aminopeptidase N, and neutral endopeptidase are largely solubilized. Upon dialysis of cholate, all these enzymes are in part reinserted in the membrane according to their original polarity. The reorientation process is however specific for the H(+)-ATPase. Cholate treatment does not increase the formation of inside-out vesicles. Thus the treatment with cholate really reorients the polarity of the H(+)-ATPase in vesicles and allows for study of the proton pumping capacity of vacuolar H(+)-ATPase of proximal tubules.
 ...
PMID:Effect of cholate on H(+)-ATPase and other proteins of dog renal brush-border membrane. 812 55

Neutral endopeptidase (NEP; also known as neprilysin and enkephalinase; EC 3.4.24.11) is a cell-surface metallopeptidase that is present in many mammalian tissues. It is particularly abundant on the brush-border membranes of the kidney proximal tubule. In this paper, the presence of NEP in purified glomeruli from dog kidney was assessed by measuring phosphoramidon- and thiorphan-sensitive [D-Ala2,Leu5]enkephalin-degrading activity. Using this assay, the Km and kcat. of the glomerular enzyme were found to be identical to those of the tubular enzyme. By Western blotting the apparent M(r) of the glomerular enzyme was found to be 104,000, compared with 94,000 for the tubular enzyme. This might be due to a different glycosylation pattern, since endoglycosidase F treatment of NEP obtained from both tissues yielded deglycosylated enzymes with similar electrophoretic mobilities. The glomerular enzyme also appears to be membrane-bound, since it was retained in the detergent-rich phase after phase separation with Triton X-114. Autoradiography experiments performed with RB104, a new highly selective and potent NEP inhibitor, showed that NEP was expressed in both glomeruli and proximal tubules. The presence in glomeruli of NEP and some other brush-border peptidases (dipeptidyl-dipeptidase IV, aminopeptidase N and angiotensin I-converting enzyme) suggests that cell-surface peptidases might play an important role as regulators of plasma-derived peptides in this part of the nephron.
 ...
PMID:Characterization of neutral endopeptidase 24.11 in dog glomeruli. 848 5

In addition to their well characterized effects at dopamine receptors, neuroleptic drugs have been shown to affect the level and in vitro metabolism of neuropeptides. In the present study, the effect of acute and subchronic administration of the neuroleptic haloperidol and the nonselective, dopamine agonist apomorphine on neuropeptidase activity was determined in regional, rat brain P2 membranes. Subchronic administration of haloperidol decreased the activity of aminopeptidase N in the frontal cortex and caudate-putamen. In contrast, subchronic administration of apomorphine increased aminopeptidase N activity in the frontal cortex and caudate-putamen. Neutral endopeptidase 24.11 also was affected differentially in the caudate-putamen, but both subchronic haloperidol and apomorphine decreased neutral endopeptidase 24.11 activity in the frontal cortex. Metalloendopeptidase 24.15 activity was decreased in the caudate-putamen after acute haloperidol and increased in the frontal cortex after acute apomorphine administration; however, no effect was noted after subchronic administration of either drug. Angiotensin converting enzyme was not affected by any treatment. Therefore, neuroleptic-induced alterations in aminopeptidase N, neutral endopeptidase 24.11 and metalloendopeptidase 24.15 activity may account for previously reported alterations in neuropeptide degradation. In view of the interaction between mesocorticolimbic dopamine neurons and neuropeptides, e.g., substance P, neurotensin and enkephalins, neuroleptic-induced alterations in the activities of neuropeptidases, and thus neuropeptide metabolism can, in turn, play a role in modulating midbrain dopaminergic activity.
 ...
PMID:Haloperidol and apomorphine differentially affect neuropeptidase activity. 861 7

The activity of two peptidases was determined in immortalized lines of thymic stromal cells. A line of total stromal cells (T-TG-St) was grown from transgenic mouse expressing temperature-sensitive SV40 T antigen under the control of the regulatory elements of the mouse major histocompatibility complex class I gene. From these cells we isolated a subset (DP-TG-St) that binds thymocytes which are mainly CD4+8+. We also assayed a clone of fetal thymic epithelial cells (BA/10) that binds CD4+8+ thymocytes. Both lines of double -positive cell-binding stroma exhibited strong activity of two peptidases, neutral endopeptidase (NEP; EC 3.4.24.11) and aminopeptidase N (APN; EC 3.4.11.2). In contrast, the activity of both enzymes was very low in the total thymic stromal line. Use of the specific inhibitors confirmed that these two enzymes were responsible for the activity observed but also suggested the presence of additional unidentified aminopeptidase(s) in the same stromal cells. The high activity of the two peptidases on stromal cells that bind thymocytes at the double-positive stage raises the possibility that they might contribute to the microenvironment of the developing thymocytes.
 ...
PMID:Activity of neutral endopeptidase and aminopeptidase N in mouse thymic stromal cells which bind double-positive thymocytes. 862 97


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>