Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P15088 (mast cell)
 14,925 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have investigated the contractile effect of bradykinin (BK) in guinea pig lung in vitro. BK induces a dose-related contraction of lung parenchymal strips which is increased significantly in the presence of 10(-5) M captopril (an angiotensin converting enzyme inhibitor) or 10(-5) M DL-thiorphan (a neutral endopeptidase inhibitor). The kininase I inhibitor, DL-2-mercaptomethyl-3-guanidino-ethylthiopropionic acid (MGTPA), has no effect on the BK-induced contraction. BK is more potent in contracting parenchymal lung strips than other contractile agents (histamine, carbachol and substance P), however the BK-induced maximal contraction is lower than those obtained with histamine and carbachol. The B1 agonist, des-Arg9-BK, does not contract lung parenchymal strips. The new BK B2 receptor antagonists (Hoe 140, NPC 17731 and NPC 17761), which possess binding affinities in the nanomolar range, inhibit the BK-induced contractile response in a dose-dependent manner. The BK-induced contraction was unaffected by propranolol, atropine, tetrodotoxin, capsaicin pre-treatment, triprolidine, methysergide, Ro 19-3704 and N omega-nitro-L-arginine-methyl-ester (L-NAME), excluding the involvement of nervous pathways, preformed mast cell mediators, platelet-activating factor and nitric oxide. However, indomethacin, a cyclooxygenase inhibitor, AA-861, a 5-lipoxygenase inhibitor, and furegrelate, a thromboxane A2 synthase inhibitor, decreased the contractile response to BK, suggesting that both cyclooxygenase and 5-lipoxygenase products are involved in this contraction.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Bradykinin-induced contraction of guinea pig lung in vitro. 799 Sep 78

The tachykinins substance P (SP) and neurokinin A (NKA) have been demonstrated in sensory airway nerves of animals and man and are thought to be neurotransmitters of local axon reflexes, generated by stimuli such as cigarette smoke, dust, histamine, and bradykinin. We previously showed that intravenous SP and NKA caused bronchoconstriction in anesthetized, mechanically ventilated rats. Pharmacologic studies suggested that this occurred by an indirect mechanism, probably mediated by acetylcholine and serotonin. In this study, we demonstrate that the bronchoconstriction caused by SP and NKA in Fisher 344 rats is accompanied by a dose-dependent release of histamine and serotonin in bronchoalveolar lavage (BAL) fluid. In rats depleted of mast cell mediators by pretreatment with compound 48/80, the effects of SP and NKA on lung resistance and serotonin in BAL fluid were abolished. Local instillation of NKA in the airways caused a significant dose-dependent increase in BAL histamine. After pretreatment with thiorphan, an inhibitor of neutral endopeptidase (NEP), the bronchoconstriction and the histamine and serotonin release in BAL fluid caused by SP and NKA were enhanced. After pretreatment with a combination of thiorphan and the angiotensin-converting enzyme inhibitor captopril, NKA and SP were almost equipotent in causing bronchoconstriction and serotonin release in the airways. This study indicates that mast cells are largely involved in the bronchoconstrictor effect of intravenously administered neurokinins in rats. As in the guinea pig, NEP is involved in the termination of the bronchoconstrictor effect of tachykinins. Moreover, NEP also affects the airway histamine and serotonin release caused by these tachykinins in the Fisher 344 rat.
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PMID:The in vivo effect of tachykinins on airway mast cells of the rat. 821 46

We have established the peptidase content of a P2 fraction (enriched in synaptosomes) and plasma membranes prepared from canine intestinal mucosa. Fourteen exo- and endopeptidases were assayed with fluorimetric or chromogenic substrates and identified by means of specific peptidase inhibitors. Post-proline dipeptidyl aminopeptidase IV, aminopeptidase M, and carboxypeptidase A were the most abundant exopeptidases, while aminopeptidases A and B, dipeptidyl aminopeptidase, pyroglutamyl peptide hydrolase I, and carboxypeptidase B displayed little, if any, activity. Endopeptidase 24.11 was the only endopeptidase that was detected in high amount. By contrast, proline endopeptidase exhibited a low activity, while angiotensin-converting enzyme, endopeptidase 24.15, endopeptidase 24.16, and cathepsin B and D-like activities were not detected. The catabolic rates of the two related neuropeptides, neurotensin (NT) and neuromedin N (NN), established that NN was inactivated 16 to 24 times faster than NT by plasma membrane and P2 fractions, respectively. Furthermore, the two peptides underwent qualitatively distinct mechanisms of degradation. A phosphoramidon-sensitive formation of NT(1-10) was detected as the major NT catabolite, indicating that NT was susceptible to an endoproteolytic cleavage elicited by endopeptidase 24.11. By contrast, NN was inactivated by the action of an exopeptidase at its N-terminus, leading to the formation of [des-Lys1]NN. The occurrence of this NN metabolite was prevented by bestatin and actinonin, but not by the aminopeptidase B inhibitor, arphamenine B, indicating that the release of the N-terminal residue of NN was likely due to aminopeptidase M.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Differential catabolic fate of neuromedin N and neurotensin in the canine intestinal mucosa. 833 46

The maltose-regulated mlr-2 gene from the hyperthermophilic archaeon Pyrococcus furiosus having homology to bacterial and eukaryal prolyl endopeptidase (PEPase) was cloned and overexpressed in Escherichia coli. Extracts from recombinant cells were capable of hydrolyzing the PEPase substrate benzyloxycarbonyl-Gly-Pro-p-nitroanilide (ZGPpNA) with a temperature optimum between 85 and 90 degrees C. Denaturing gel electrophoresis of purified PEPase showed that enzyme activity was associated with a 70-kDa protein, which is consistent with that predicted from the mlr-2 sequence. However, an apparent molecular mass of 59 kDa was obtained from gel permeation studies. In addition to ZGPpNA (K(Mapp) of 53 microM), PEPase was capable of hydrolyzing azocasein, although at a low rate. No activity was detected when ZGPpNA was replaced by substrates for carboxypeptidase A and B, chymotrypsin, subtilisin, and neutral endopeptidase. N-[N-(L-3-trans-Carboxirane-2-carbonyl)-L-Leu]-agmatine (E-64) and tosyl-L-Lys chloromethyl ketone did not inhibit PEPase activity. Both phenylmethylsulfonyl fluoride and diprotin A inhibited ZGPpNA cleavage, the latter doing so competitively (K(lapp) of 343 microM). At 100 degrees C, the enzyme displayed some tolerance to sodium dodecyl sulfate treatment. Stability of PEPase over time was dependent on protein concentration; at temperatures above 65 degrees C, dilute samples retained most of their activity after 24 h while the activity of concentrated preparations diminished significantly. This decrease was found to be due, in part, to autoproteolysis. Partially purified PEPase from P. furiosus exhibited the same temperature optimum, molecular weight, and kinetic characteristics as the enzyme overexpressed in E. coli. Extracts from P. furiosus cultures grown in the presence of maltose were approximately sevenfold greater in PEPase activity than those grown without maltose. Activity could not be detected in clarified medium obtained from maltose-grown cultures. We conclude that mlr-2, now called prpA, encodes PEPase; the physiological role of this protease is presently unknown.
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PMID:Overexpression and characterization of a prolyl endopeptidase from the hyperthermophilic archaeon Pyrococcus furiosus. 917 7

In guinea pig airways, contractions induced by leukotriene D4 or antigen are thought to be mediated primarily by an action of the agonist or of released mast cell-derived mediators directly on the airway smooth muscle cell. An indirect contractile action mediated by endogenous tachykinins also has been described for both of these stimuli. The present study evaluated the contribution of endogenous tachykinins to ovalbumin- and leukotriene D4-induced contractions in the guinea pig bronchus by modulating the concentrations of tachykinins within the tissues and by using neurokinin receptor antagonists. Acute depletion of tachykinins with capsaicin had no effect on responses elicited by either stimulus. Similarly, tetrodotoxin treatment failed to influence leukotriene D4-induced contractions. Inhibitors of neutral endopeptidase (thiorphan) and angiotensin-converting enzyme (lisinopril) enhanced neurally mediated tachykininergic responses and potentiated leukotriene D4. The latter effect persisted in the presence of tetrodotoxin or the neurokinin antagonists CP99994 and SR48968 and in tissues treated acutely with capsaicin. The potentiation was absent, however, from bronchi incubated with L-cysteine. Ovalbumin-induced contractions were unaltered by inhibition of neutral endopeptidase and angiotensin-converting enzyme. These observations suggest that tachykinins are not involved in mediation of leukotriene D4- or antigen-induced contractions of the guinea pig bronchus. The ability of protease inhibitors to potentiate leukotriene D4 but not antigen-induced responses is therefore ascribed to inhibition of bioinactivation of leukotriene D4 to leukotriene E4.
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PMID:Absence of tachykinin involvement in leukotriene D4 and antigen-induced contraction of guinea pig isolated bronchus. 939 82

Two series of compounds synthesized as specific matrix metalloproteinase (MMP) inhibitors have been evaluated for their inhibition of non-MMPs. In a series of substituted succinyl hydroxamic acids, some were found to be significant (IC50 < 1 microM) inhibitors of leucine (microsomal) aminopeptidase, neprilysin (3.4.24.11), and thermolysin. Macrocyclic compounds in which the alpha carbon of the succinyl hydroxamate is linked to the side chain of the P2' amino acid were found to be good inhibitors of aminopeptidase, but not of neprilysin or thermolysin. Compounds of neither series were found to be significant inhibitors of angiotensin converting enzyme or carboxypeptidase A.
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PMID:Evaluation of the inhibition of other metalloproteinases by matrix metalloproteinase inhibitors. 1053 76

The present study examined the roles of endothelin-converting enzyme (ECE), neutral endopeptidase (NEP) and mast cell chymase as processors of the endothelin (ET) analogues ET-1(1-21), ET-1(1-31) and big ET-1 in the trachea of allergic mice. Male CBA/CaH mice were sensitized with ovalbumin (10 microg) delivered intraperitoneal on days 1 and 14, and exposed to aerosolized ovalbumin on days 14, 25, 26 and 27 (OVA mice). Mice were killed and the trachea excised for histological analysis and contraction studies on day 28. Tracheae from OVA mice had 40% more mast cells than vehicle-sensitized mice (sham mice). Ovalbumin (10 microg/ml) induced transient contractions (15+/-3% of the C(max)) in tracheae from OVA mice. The ECE inhibitor CGS35066 (10 microM) inhibited contractions induced by big ET-1 (4.8-fold rightward shift of dose-response curve; P<0.05), but not those induced by either ET-1(1-21) or ET-1(1-31). The chymase inhibitors chymostatin (10 microM) and Bowman-Birk inhibitor (10 microM) had no effect on contractions induced by any of the ET analogues used. The NEP inhibitor CGS24592 (10 microM) inhibited contractions induced by ET-1(1-31) (6.2-fold rightward shift; P<0.05) but not ET-1(1-21) or big ET-1. These data suggest that big ET-1 is processed predominantly by a CGS35066-sensitive ECE within allergic airways rather than by mast cell-derived proteases such as chymase. If endogenous ET-1(1-31) is formed within allergic airways, it is likely to undergo further conversion by NEP to more active products.
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PMID:Role of endothelin-converting enzyme, chymase and neutral endopeptidase in the processing of big ET-1, ET-1(1-21) and ET-1(1-31) in the trachea of allergic mice. 1219 21

This review provides a new insight into the participation of neuropeptides, notably substance P (SP), in the pathophysiology of acne. We show morphological alterations of sebaceous glands elicited by SP and differences in expression of various neurogenic factors in association with sebaceous glands in acne-prone versus normal facial skin. In vitro studies reveal that SP promotes both the proliferation and the differentiation of sebaceous glands. SP induces the expression of neutral endopeptidase, a potent neuropeptide-degrading enzyme, in sebaceous germinative cells and of E-selectin by perisebaceous venules. Facial skin from acne patients is characterized by rich innervation, by increased numbers of SP-containing nerves and mast cells, and by strong expression of neutral endopeptidase in sebaceous glands and E-selectin in venules around sebaceous glands, compared with normal skin. Mast cell-derived IL-6 and TNF-alpha, followed by SP-stimulated degranulation, have the potential to induce nerve growth factor expression by sebaceous cells which results in the promotion of innervation and in the expression of E-selectin, respectively. SP enhances mast cell proliferation through up-regulation of stem cell factor expression in fibroblasts. These findings suggest the involvement of neurogenic factors, such as neuropeptides, in the disease process of acne and explain the possible mechanism of the exacerbation of acne from a neurological point of view.
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PMID:Neuropeptides and sebaceous glands. 1237 Jan 27

The renin-angiotensin system is a key target for drugs combating cardiovascular disease. Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor type-1 (AT1 receptor) blockers are well known. However, angiotensin peptides can be generated through a number of pathways besides the classic system. This review outlines some of these pathways, their relation to the classic system and the likely effect of inhibiting them. Renin is still the key enzyme in angiotensin peptide generation and seems to be the only route to angiotensin I formation in vivo. Renin inhibitors may have some advantages in terms of specificity. Also, by blocking angiotensin I generation, the production of downstream bioactive angiotensin I metabolites should also be blocked. Chymase, a mast cell serine protease, cleaves angiotensin I to produce angiotensin II and may be important at sites of inflammation such as atherosclerotic plaque. Angiotensin-converting enzyme 2 (ACE2), a carboxypeptidase structurally related to ACE but resistant to ACE inhibitors, has a protective effect on cardiac function. Neutral endopeptidase 24.11 breaks down both atrial natriuretic peptide and angiotensin II. Inhibiting it potentiates the action of endogenous atrial peptide but only affects circulating angiotensin II when basal levels are above normal. Dual inhibitors of ACE and endopeptidase 24.11 may be of value where there is both sodium retention and increased angiotensin II. Targeting the renin-angiotensin system by gene therapy or antibody treatment may provide a longer-term treatment for hypertension.
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PMID:Targeting the renin-angiotensin system: what's new? 1563 41

Alopecia areata (AA) is an autoimmune disorder of the hair follicle characterized by inflammatory cell infiltrates around actively growing (anagen) hair follicles. Substance P (SP) plays a critical role in the cutaneous neuroimmune network and influences immune cell functions through the neurokinin-1 receptor (NK-1R). To better understand the role of SP as an immunomodulatory neuropeptide in AA, we studied its expression and effects on immune cells in a C3H/HeJ mouse model for AA. During early stages of AA development, the number of SP-immunoreactive nerve fibers in skin is increased, compared to non-affected mice. However, during advanced stages of AA, the number of SP-immunoreactive nerves and SP protein levels in skin are decreased, whereas the expression of the SP-degrading enzyme neutral endopeptidase (NEP) is increased, compared to control skin. In AA, NK-1R is expressed on CD8+ lymphocytes and macrophages accumulating around affected hair follicles. Additional SP supply to the skin of AA-affected mice leads to a significant increase of mast cell degranulation and to accelerated hair follicle regression (catagen), accompanied by an increase of CD8+ cells-expressing granzyme B. These data suggest that SP, NEP, and NK-1R serve as important regulators in the molecular signaling network modulating inflammatory response in autoimmune hair loss.
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PMID:Substance P as an immunomodulatory neuropeptide in a mouse model for autoimmune hair loss (alopecia areata). 1750 60


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