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

Membrane metalloendopeptidase (MMEP; EC 3.4.24.11; enkephalinase) catalyzes the degradation of endothelins, enkephalins, atrial natriuretic factor, substance P, and other small bioactive peptides. We found that MMEP is present in human endometrium, localized primarily in stromal cells of this tissue, and that the specific activity of MMEP (and immunoreactive MMEP protein) in endometrial tissue is correlated in a highly significant positive manner with the concentration of progesterone in plasma. In estrogen-treated, human endometrial stromal cells in monolayer culture, the specific activity of MMEP increases in response to treatment with progestin; and, this increase is accompanied by increases in immunoreactive MMEP protein, newly synthesized MMEP, and MMEP mRNA.
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PMID:Progesterone-regulated cyclic modulation of membrane metalloendopeptidase (enkephalinase) in human endometrium. 174

Neutral endopeptidase (NEP, also known as enkephalinase, CALLA, or EC 3.4.24.11) is a membrane-bound peptidase present in many different cell types. Previous studies have shown that it modulates the actions of a variety of biologically active peptides on several airway responses. More recent studies have demonstrated that reductions in neutral endopeptidase activity in animal airways is associated with increased responses to exogenously applied and endogenously released peptides. To study the regulation of NEP expression, we used human airway epithelial cells transformed in vitro with an origin-defective SV40 plasmid. Enzymatic activity, measured using [3H-Tyr,D-Ala2]leucine enkephalin, increased with cell density (1.4 ng/10(6) cells at 530 cells/cm2 and 21 ng/10(6) cells at confluence, 400 X 10(3) cells/cm2). In both confluent and nonconfluent cultures, the glucocorticoid budesonide increased neutral endopeptidase activity in time- and concentration-dependent fashions. Maximal increases of 10 ng/10(6) cells greater than control were observed after 6 days of incubation at 10(-7) M budesonide. Dexamethasone also increased NEP, suggesting that the effect is due to glucocorticoid receptor effects. Transcription, as assessed by Northern blot analysis of total cellular RNA, showed that NEP-specific RNAs also increased with increasing concentration of glucocorticoid. We conclude that neutral endopeptidase can be increased by cell growth or density and by glucocorticoids and that the effects of glucocorticoids are mediated by increased NEP gene expression.
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PMID:Glucocorticoids induce neutral endopeptidase in transformed human tracheal epithelial cells. 184 94

Enkephalinase (endopeptidase 24.11) is a metallopeptidase that is able to cleave not only neuropeptides and hormones but also immune mediators. The enzyme was quantified in synovial fluid obtained from 36 swollen joints. Its concentration correlated with the synovial fluid cell count, mainly the polymorphonuclear cells and lymphocytes, and with the erythrocyte sedimentation rate. No statistically significant difference in enkephalinase levels was demonstrated between the groups of patients with rheumatoid arthritis, seronegative spondylarthropathy, microcrystalline arthritis, or osteoarthritis. The presence of enkephalinase in the synovial fluid could reflect the intensity of the inflammatory process, or it could represent a physiologic regulator of inflammation and pain within the joint.
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PMID:Enkephalinase: a physiologic neuroimmunomodulator detected in the synovial fluid. 185 79

A noncholinergic, nonadrenergic nervous system has been described, involving the sensory nerves in the airways. Chemicals, dusts and other irritants stimulate these sensory nerves to release substance P and related neuropeptides. These neuropeptides have the remarkable ability to affect multiple cells in the airways and to provoke many responses including cough, mucus secretion, smooth muscle contraction, plasma extravasation and neutrophil adhesion. This series of effects is termed "neurogenic inflammation." An enzyme exists on the surfaces of all lung cells that contain receptors for these neuropeptides. This enzyme, neutral endopeptidase (NEP), by cleaving and thus inactivating the neuropeptides, limits the concentration of the neuropeptide that reaches the receptor on the cell surface. Thus, neurogenic inflammatory responses are normally mild and presumably protective in nature. However, when NEP is inhibited pharmacologically (with NEP inhibitors) or by cigarette smoke, respiratory viral infection, or by inhalation of the industrial pollutant toluene diisocyanate, neurogenic inflammatory responses are exaggerated. Delivery of exogenous human recombinant NEP inhibits neurogenic inflammation. Finally, evidence is provided that corticosteroids suppress neurogenic plasma extravasation and that this drug can upregulate NEP in human airway tissue. Neutral endopeptidase cleaves multiple peptides. Thus, its selectivity resides, at least in part, on its fixed location on the surfaces of specific cells where it can modulate effects of peptides exposed to the cells' surfaces.
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PMID:Neutral endopeptidase modulates neurogenic inflammation. 188 1

Neutral endopeptidase (EC 3.4.24.11, NEP) is a Zn-metallopeptidase involved in the degradation of biologically active peptides, notably the enkephalins and atrial natriuretic peptide. Recently, the structure of the active site of this enzyme has been probed by site-directed mutagenesis, and 4 amino acid residues have been identified, namely 2 histidines (His583 and His587), which act as zinc-binding ligands, a glutamate (Glu584) involved in catalysis, and an arginine residue (Arg102), suggested to participate in substrate binding. Site-directed mutagenesis has now been used to investigate the role of 4 other arginine residues (Arg408, Arg409, Arg659, and Arg747) that have been proposed as possible active site residues and to further analyze the role of Arg102. In each case, the arginine was replaced with a methionine, and both enzymatic activity and the IC50 values of several NEP inhibitors were measured for the mutated enzymes and compared to wild-type enzyme. The results suggest that 2 arginines, Arg102 and Arg747, could both be important for substrate and inhibitor binding. Arg747 seems to be positioned to interact with the carbonyl amide group of the P'1 residue and can be modified when the enzyme is treated with the arginine-specific reagents phenylglyoxal and butanedione. Arg102 could be positioned to interact with the free carboxyl group of a P'2 residue in some substrates and inhibitors and can be modified by phenylglyoxal but not by butanedione. The results could explain the dual dipeptidylcarboxypeptidase and endopeptidase nature of NEP.
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PMID:Evidence that both arginine 102 and arginine 747 are involved in substrate binding to neutral endopeptidase (EC 3.4.24.11). 198 94

The enzyme neutral endopeptidase (NEP) is bound to the membranes of selected cells in the airways that have receptors for tachykinins. The location of the enzyme, along with its selectivity of substrates (tachykinins are a preferred substrate), allows the enzyme to cleave tachykinins that come close to the cell-surface receptors. By cleaving and thus inactivating tachykinins released during stimulation of the sensory nerves, NEP limits the degree of neurogenic inflammation. Neutral endopeptidase exists in the basal cells of the airway epithelium, nerves, smooth muscle, glands, blood vessels, and perhaps other cells. Thus, the enzyme modulates smooth muscle contraction, gland secretion, cough, vascular permeability, and neutrophil adhesion. Decreased NEP activity occurs with epithelial removal, during respiratory viral infections, and during exposure to irritants (e.g., cigarette smoke and toluene diisocyanate). Delivery of recombinant NEP (rNEP) by aerosol suppressed cough responses during neurogenic inflammation. We suggest that decreased NEP activity will result in exaggerated neurogenic inflammation and may play an important role in inflammatory diseases in airways. Furthermore, drugs that cause up-regulation of NEP may play a therapeutic role by suppressing neurogenic responses. Replacement therapy with rNEP may be useful in diseases where inflammatory peptides (e.g., tachykinins, bradykinin) play a role in pathogenesis.
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PMID:Modulation of neurogenic inflammation by neutral endopeptidase. 200 87

Neutral endopeptidase exists on the membranes of many cells in the airways. By cleaving and thus inactivating tachykinins released from sensory nerves, NEP limits the actions of these peptides. The selectivity of the enzyme is due, at least in part, to its close association with tachykinin receptors. By cleaving and inactivating the tachykinins, it limits the concentration of tachykinin that reaches the receptor. Decreased NEP activity produced by selective enzyme inhibitors, air pollutants, infections, and oxidants leads to exaggerated neurogenic inflammation. We speculate that the multiple stimuli that enter the airways of healthy individuals normally produce small, nonsymptomatic neurogenic inflammatory responses. However, when NEP activity is decreased, the responses become exaggerated and may contribute to the pathogenesis of diseases such as asthma and bronchitis.
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PMID:Decreased neutral endopeptidases: possible role in inflammatory diseases of airways. 216 84

The physiology, the pharmacology and the biochemistry of the atrial natriuretique factor (ANF) have been investigated and documented by numerous studies and works since its discovery and cloning ten years ago. More recently, the physiopathological aspect of ANF biosynthesis and secretion by the whole heart during overload and congestive heart failure was reported in experimental models and in human patients. Moreover the cyclic GMP which is the ANF second messenger, egressed from endothelial cells, was correlated with the production of ANF. Therefore the activation of heart endocrine function from ANF gene over-expression to peripheral cyclic GMP appeared as an independent prognosis indicator in congestive heart failure. Two types of ANF receptors have been recently cloned. One is the particulate guanylate cyclase, the second is a clearance receptor involved in the endocytosis and lysozomial degradation of ANF in target cells. Neutral endopeptidase, an ectoenzyme present in different tissues and particularly in the kidney is also capable to cleave ANF in unefficient peptide. The blockade of ANF metabolism by clearance receptor antagonists and neutral endopeptidase inhibitor potentializes the biological effect of exogenous and endogenous ANF particularly on the renal function. This approach of ANF metabolism-inhibition opens new ways on the future of ANF in cardiovascular therapeutic.
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PMID:[Atrial natriuretic factor. Current data and future perspectives]. 217 42

Neutral endopeptidase-24.11 (EC 3.4.24.11) (NEP) is a transmembrane metallo-endopeptidase that has been shown to be involved in the degradation of several mammalian neuropeptides, including enkephalins. The enzyme has recently been found to be specifically associated with the axonal and synaptic membranes of neurons in the globus pallidus of the pig brain. This result suggests that neurons must possess mechanisms for targeting NEP to particular membrane domains. Study of these mechanisms would greatly benefit from the existence of an established neuron-like cell line capable of expressing and targeting NEP to specific membrane domains. For this reason we have used a retroviral vector containing the cDNA for rabbit kidney NEP to express this enzyme in a mouse neuroblastoma cell line (Neuro2A). Labelling of the cell surface with an antibody coupled to colloidal gold particles and examination of the cells by electron microscopy revealed a non-uniform distribution of NEP at the surface of the cells, the protein being preferentially associated with the membrane of neurites compared with the cell body. This observation suggests that Neuro2A cells possess a mechanism for targeting NEP to specific domains of the plasma membrane. This cell line could thus constitute a good model for studying the mechanisms responsible for targeting this enzyme to specialized regions of the plasma membrane.
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PMID:Recombinant neutral endopeptidase-24.11 expressed in mouse neuroblastoma cells is associated with neurite membranes. 233 3

Neutral endopeptidase (NEP; EC 3.4.24.11) efficiently hydrolyses many neuropeptides. To determine the distribution of NEP, a possible regulatory enzyme for the neuropeptide-induced leukocyte activation, among human leukocytes, we investigated the enzymatic activity of NEP in each cell type of human peripheral blood leukocytes. The activity of NEP assessed by an NEP inhibitor phosphoramidon-sensitive Met5-enkephalin degrading activity was present in neutrophils (59.0 +/- 9.1 pmol/min 10(6) cells); however, the NEP activity was virtually absent in mononuclear cells, eosinophils and basophils. Common acute lymphoblastic leukemia antigen (CALLA) detected immunocytochemically with three anti-CALLA antibodies, whose amino acid sequence has been shown to be identical with that of NEP, was also found only in neutrophils, but not in other blood leukocytes. It is suggested that NEP might regulate the neuropeptide-induced activation of human neutrophils.
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PMID:[Neutral endopeptidase activity in human peripheral blood leukocytes]. 237 83


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