Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20366 (substance P)
21,176 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The present study examined the effects of intrathecal (i.t.) injection of calcitonin gene-related peptide (CGRP) on caudally directed biting and scratching induced by i.t. substance P (SP), bombesin (BBS), strychnine (STR), and kainic acid (KA). CGRP alone (5.25, 10.5 and 21 nmol) had no effect on these behaviors, but CGRP pretreatment produced a dose-related enhancement of behaviors induced by SP or BBS, but not by KA or STR. 2-Amino-5-phosphonovaleric acid (APV, 25 nmol), a selective N-methyl-D-aspartate (NMDA) receptor antagonist, did not block the CGRP potentiation of SP and BBS induced behaviors. CGRP, however, failed to enhance scratching and biting induced by a SP analogue [pGlu5-Mephe8-MeGly9]SP(5-11) (Dime-C7) that is resistant to enzymatic degradation by SP endopeptidase. These findings demonstrate that CGRP potentiates SP induced behavioral responses via inhibition of neuropeptide degradation and that this mechanism may serve as a physiological mechanism of SP modulation.
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PMID:Calcitonin gene-related peptide enhances substance P-induced behaviors via metabolic inhibition: in vivo evidence for a new mechanism of neuromodulation. 137 8

The purpose of this study was to determine whether substance P (SP), neurokinin A (NKA), and neurokinin B (NKB) induce the release of neutrophil chemotactic activity (NCA) from bovine bronchial epithelial cells (BBEC) and whether neutral endopeptidase (NEP), a membrane-bound metalloenzyme that hydrolyzes tachykinins, modulates these effects. BBEC monolayers were exposed to SP, NKA, and NKB in the absence or presence of phosphoramidon (10(-6) M), a selective NEP inhibitor, for 72 h. Using a modified blind-well in vitro neutrophil chemotaxis assay, we found that tachykinin-exposed BBEC culture supernatant fluids induced significant neutrophil chemotaxis compared with supernatants obtained from unstimulated BBEC. Maximal effect was observed after 48 h of incubation and at SP concentration of 10(-13) M [92 +/- 3 (SP) vs. 64 +/- 2 (media) cells/high-power field (HPF), mean +/- SE, n = 7, P less than 0.05]. Release of NCA was mediated by the COOH-terminal of the SP molecule. The rank order of potency of tachykinins in inducing release of NCA was SP greater than NKA = NKB. SP-induced response was significantly potentiated by phosphoramidon (109 +/- 3 vs. 92 +/- 3 cells/HPF, n = 7, P less than 0.05), whereas other proteinase inhibitors had no effect. The released NCA was composed of protein and lipid-soluble components. These data indicate that mammalian tachykinins induce the release of NCA from BBEC and that NEP modulates these effects. We suggest that tachykinins regulate neutrophil recruitment into the lower respiratory tract, in part, by inducing the release of NCA from airway epithelial cells.
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PMID:Bronchial epithelial cells release neutrophil chemotactic activity in response to tachykinins. 138 Nov 52

Kinins and substance P have been implicated in the pathogenesis of inflammatory arthritis by virtue of their abilities to induce vasodilation, edema, and pain. The relative biological potencies of these peptides in vivo would depend at least in part upon their rates of catabolism in the joint. We hypothesized that human synovial lining cells may regulate intraarticular levels of kinins and neuropeptides via degradation by cell surface-associated peptidases. We exposed intact human synovial fibroblasts to kinins and substance P, in the presence or absence of specific peptidase inhibitors, and measured the amount of intact substrate remaining and degradation product(s) generated over time. Aminopeptidase M (AmM; EC 3.4.11.2), neutral endopeptidase-24.11 (NEP-24.11; EC 3.4.24.11), and dipeptidyl(amino)peptidase IV (DAP IV; EC 3.4.14.5) were identified on the cell surface of synovial cells. Bradykinin degradation was due entirely to NEP-24.11 (1.39 +/- 0.29 nmol/min per well). Lysylbradykinin was also degraded by NEP-24.11 (0.80 +/- 0.19 nmol/min per well); however, in the presence of phosphoramidon, AmM-mediated conversion to bradykinin (3.74 +/- 0.46 nmol/min per well) could be demonstrated. The combined actions of NEP-24.11 (0.93 +/- 0.15 nmol/min per well) and DAP IV (0.84 +/- 0.18 nmol/min per well) were responsible for the degradation of substance P. AmM (2.44 +/- 0.33 nmol/min per well) and NEP-24.11 (1.30 +/- 0.45 nmol/min per well) were responsible for the degradation of the opioid peptide, [Leu5]enkephalin. The identity of each of the three peptidases was confirmed via synthetic substrate hydrolysis, inhibition profile, and immunological identification. The profiles of peptidase enzymes identified in cells derived from rheumatoid and osteoarthritic joints were identical. These data demonstrate the human synovial fibroblast to be a rich source of three specific peptidases and suggest that it may play a prominent role in regulating peptide levels in the joint.
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PMID:Cultured human synovial fibroblasts rapidly metabolize kinins and neuropeptides. 138 26

We investigated the effects of collagen II-induced arthritis on two cerebrospinal fluid (CSF) enzymes converting dynorphin A and substance P (SP), namely dynorphin-converting enzyme (DCE) and substance P endopeptidase (SPE). The products generated by these enzymes are the bioactive fragments Leu-enkephalin-Arg6 and substance P, respectively. The strain used (DA rats) is very sensitive towards induction of arthritis. The collagen arthritis is a chronic autoimmune arthritis induced by native rat collagen type II (CII). Following intradermal injection of CII into the tailbase. CSF was sampled on day 21 (acute arthritis) and day 38 (chronic arthritis). Control rats were untreated because the strain used developed an acute and self-limited arthritis (adjuvant arthritis) when administered vehicle (i.e. incomplete Freund's adjuvant). The DCE activity was significantly lowered in the acute phase of arthritis (P less than 0.05) when analysed with two-factor analysis of variance (ANOVA). The enzyme converting SP (SPE) also showed a significant decrease in the acute phase of arthritis (P less than 0.05). These results demonstrate that both DCE and SPE are affected in the acute phase of arthritis. A functional role of these enzymes in processing pain-related neuropeptides is therefore implicated.
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PMID:Decreased neuropeptide-converting enzyme activities in cerebrospinal fluid during acute but not chronic phases of collagen induced arthritis in rats. 138

To investigate the role of neuropeptides in allergic inflammation, we examined the effect of peptides on eosinophil chemotaxis. Eosinophils were purified from the blood of allergic and normal subjects using a discontinuous Percoll density gradients. Chemotaxis was induced by platelet-activating factor (PAF) and leukotriene B4, and was assayed by a modified Boyden's chamber technique. Four neuropeptides were examined in this study: substance P (SP), neurokinin A, calcitonin gene-related peptide (CGRP), and cholecystokinin octapeptide. Peptides alone (10 nM to 10 microM) were not chemotactic for eosinophils. However, when eosinophils were pre-treated with peptides (100 nM) at 37 degrees C for 30 min, chemotactic response to PAF (10 nM) was significantly enhanced (p < 0.01) in allergic subjects; % control by SP, neurokinin A, CGRP and cholecystokinin octapeptide was 269 +/- 42, 243 +/- 32, 227 +/- 21, and 251 +/- 42, respectively (n = 8). Similar results were obtained in leukotriene B4-induced eosinophil chemotaxis. In contrast, no enhancement was observed in normal subjects. Potentiating effect of SP and CGRP on PAF-induced eosinophil chemotaxis in allergic subjects was significantly attenuated by SP antagonist [D-Pro2,D-Trp7,9]-SP and human CGRP (8-37) receptor antagonist, respectively. Neutral endopeptidase inhibitors (phosphoramidon, leupeptin, and bestatin) failed to significantly augment the PAF-induced eosinophil chemotaxis when the cells were pretreated with various peptides and neutral endopeptidase inhibitors. The C-terminal fragment of SP (SP6-11) had an effect similar to that of the intact SP molecule, whereas no potentiating effect by the N-terminal of SP (SP1-9) was observed. These results suggest that neuropeptides may play a significant role in eosinophil infiltration by priming cells in allergic inflammation.
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PMID:Neuropeptides modulate human eosinophil chemotaxis. 138 21

Neutral endopeptidases EC 3.4.24.11 and EC 3.4.24.15, widely distributed zinc metalloendopeptidases, degrade a number of biologically active peptides including substance P, bradykinin, neurotensin, and luteinizing hormone-releasing hormone. In this study we measured EC 3.4.24.11 and EC 3.4.24.15 activity in alveolar macrophages, key inflammatory cells in the lung that produce and respond to a large number of bioactive substances including chemotactic peptides, with the substrates glutaryl-ala-ala-phe-2-naphthylamide and tertiary butoxycarbonyl-phe-ala-ala-phe-paraaminobenzoate, respectively. We found that specific activity of EC 3.4.24.15, defined as activity inhibited with N-[(1RS)-carboxy-3-phenylpropyl]-ala-ala-phe-paraaminobenzoate+ ++, was significantly higher (p < 0.001) in cells from Sprague-Dawley rats (485 +/- 123 nmol/mg protein.hr) than in cells from Hartley guinea pigs (138 +/- 94 nmol/mg protein.hr), healthy human male smokers (121 +/- 73 nmol/mg protein.hr) and healthy human male nonsmokers (94 +/- 12). In contrast, activity of EC 3.4.24.11, defined as activity inhibited with N-[(1RS)-carboxy-3-phenylpropyl]-phe-paraaminobenzoate, was significantly higher (p < 0.001) in cells from human smokers (689 +/- 167 nmol/mg protein.hr) and nonsmokers (762 +/- 136 nmol/mg protein.hr) than in cells from rats (52 +/- 12 nmol/mg protein.hr) and guinea pigs (34 +/- 14 nmol/mg protein.hr). An additional activity in alveolar macrophages toward tertiary butorycarbonyl-phe-ala-ala-phe-paraaminobenzoate was inhibited with L-3-carboxy-trans-2,3-epoxypropionyl-leucylamido-(4-guanido) butane, a specific inhibitor of cysteine proteinases, a finding of interest because in general enzymes in this class show little activity at neutral pH.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Identification of two zinc metalloendopeptidases in alveolar macrophages of rats, guinea pigs, and human beings. 140 35

A novel metallo-endopeptidase from human neuroblastoma NB-OK-1 cells was partially purified and characterized. This enzyme activity was detected in the culture medium and could be detached from intact cells by gentle washing, suggesting a peripheral localization of the enzyme. This endopeptidase inactivated Atrial Natriuretic Peptide (ANP) by a unique and selective cleavage of the Ser123-Phe124 bond. It also produced hydrolysis at the Xaa-Phe, Xaa-Leu, or Xaa-Ile bonds of other peptide hormones such as bradykinin, somatostatin 14, litorin, substance P, neuromedin C and angiotensin II. The substrate selectivity and inhibition profile of the enzyme showed obvious similarities with the peptide hormone inactivating endopeptidase (PHIE) recently purified from Xenopus laevis skin secretions and indicated a thermolysin-like activity distinct from neutral endopeptidase (EC 3.4.24.11) and from angiotensin converting enzyme (EC 3.4.15.1).
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PMID:A new metallo- endopeptidase from human neuroblastoma NB-OK-1 cells which inactivates atrial natriuretic peptide by selective cleavage at the Ser123-Phe124 bond. 153 Oct 11

The enzyme neutral metalloendopeptidase (E.C. 3.4.24.11), also known as the common acute lymphocytic leukemia antigen, neutral endopeptidase, or enkephalinase, functions as an inactivator of a wide variety of signaling oligopeptides such as substance P, neurokinin A, enkephalins, endothelin, atrial natriuretic factor, and formyl chemotactic peptides. A cDNA clone isolated from a human lung library encodes a fragment of neutral metalloendopeptidase containing an internal 81 base pair deletion when compared with the human placental cDNA for this enzyme. Comparison of the deleted cDNA sequence with the intron-exon structure recently determined as the common acute lymphocytic leukemia antigen reveals that the 81 base pairs corresponds precisely with exon 16. RNA analysis using splice junction oligonucleotides indicates that the 16 del form constitutes a minor but significant fraction of the RNA species present in human lung. Expression of constructs containing "wild type" and "exon 16 del" neutral endopeptidases in COS-7 cells reveals that deletion of this 27 amino acid segment reduces enzymatic activity toward the synthetic substrate glutaryl-alanyl-alanyl-phenyl-alanyl-4-methoxy-2-naphthylamide to barely detectable levels.
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PMID:Exon 16 del: a novel form of human neutral endopeptidase (CALLA). 153 84

We examined the effect of rapid intravenous infusion of neurokinin A (NKA) and selected COOH-terminal NKA fragments on pulmonary conductance (GL) and dynamic compliance in anesthetized mechanically ventilated guinea pigs. The rank order of the dose of peptide required to reduce GL by 50% (ED50GL) was NKA = NKA2-10 = NKA3-10 = NKA4-10 less than NKA5-10 much less than NKA6-10. The time course of bronchoconstriction induced by NKA2-10, NKA3-10, and NKA4-10 was similar to that induced by NKA, whereas NKA5-10 and NKA6-10 each had a shorter duration of action than NKA for a similar induced maximal change in GL. To determine whether degradation of these NKA fragments by neutral endopeptidase (NEP) modulates their bronchoconstrictor activity as it does for native NKA, we examined the effect of the NEP inhibitor SCH32615 on NKA3-10-, NKA5-10-, and NKA6-10-induced changes in GL. We have previously reported that the ED50GL for NKA was approximately 20-fold lower in animals pretreated with SCH32615 (1 mg/kg) than in control guinea pigs. SCH32615 caused a 16-fold decrease in ED50GL for NKA3-10 (P less than 0.001) but had no effect on airway responses to NKA5-10 or NKA6-10. The results demonstrate that the magnitude and duration of bronchoconstriction induced by potential aminopeptidase degradation products of NKA are similar to those of the native peptide. Aminopeptidases do not, therefore, have the capacity to modulate the bronchoconstriction induced by this peptide.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Relative bronchoconstrictor activity of neurokinin A and neurokinin A fragments in guinea pigs. 165 59

It has recently been demonstrated that luminal exposure of airway segments in vitro to HOCl produces airway muscle hyperresponsiveness to substance P and a decrease in neutral endopeptidase (NEP) activity of tissue segment homogenates, suggesting that HOCl may decrease airway epithelial cell NEP activity. To confirm that this effect occurs in humans and to investigate possible subcellular mechanisms for it, we assessed HOCl exposure of the human airway epithelial cell line Calu-1. These cells, grown to confluency in Dulbecco's modified Eagle medium with 10% fetal bovine serum and penicillin-streptomycin, were exposed in situ for 5 min to 100 microM HOCl in a phosphate-buffered saline solution (PBS; pH 7.0 at 37 degrees C) or to PBS alone. Thereafter, cells were rinsed and assayed for NEP activity employing reverse-phase high-pressure liquid chromatography. This activity was characterized by the generation of phosphoramidon-inhibitable product (ANA) cleaved from the synthetic substrate succinyl-(ala)3-p-nitroaniline during a 30 min incubation at 37 degrees C. Cell viability was assessed by changes in LDH release, trypan blue exclusion, and cell volume. In some experiments, crude plasma membrane and soluble components of exposed cells were isolated and differential NEP activity was assayed. We found that a 5 min exposure to HOCl decreased whole cell NEP activity from 74.1 +/- 4.4 (mean +/- SE) to 54.3 +/- 6.0 pmoles of ANA/min/10(6) cells (p less than 0.05), while no parameter of cell viability was affected. NEP activity in the crude membrane fraction decreased 36.3 +/- 3.1% after exposure (p less than 0.01), whereas NEP activity in the soluble fraction increased 4.0 +/- 0.6%. Isolated membrane NEP exposed by itself was not affected. Subsequent experiments with reducing agents demonstrated that NEP activity of cell cultures pretreated with 100 mM of either beta-mercaptoethanol or dithiothrietol before HOCl exposure was not significantly different from control values. We conclude that whole cell HOCl exposure decreases Calu-1 plasma membrane NEP. This loss appears to occur by internalization of cell membrane NEP.
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PMID:HOCl exposure of a human airway epithelial cell line decreases its plasma membrane neutral endopeptidase. 166 4


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