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Query: UNIPROT:P20366 (
substance P
)
21,176
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
1. Proteases regulate cells by cleaving proteinase-activated receptors (PARs). Thrombin and trypsin cleave PAR-1 and
PAR-2
on neurons and astrocytes of the brain to regulate morphology, growth and survival. We hypothesized that thrombin and mast cell tryptase, which are generated and released during trauma and inflammation, regulate enteric neurons by cleaving PAR-1 and
PAR-2
. 2. We detected immunoreactive PAR-1 and
PAR-2
in > 60 % of neurons from the myenteric plexus of guinea-pig small intestine in primary culture. A large proportion of neurons that expressed
substance P
, vasoactive intestinal peptide or nitric oxide synthase also expressed PAR-1 and
PAR-2
. We confirmed expression of PAR-1 and
PAR-2
in the myenteric plexus by RT-PCR using primers based on sequences of cloned guinea-pig receptors. 3. Thrombin, trypsin, tryptase, a filtrate from degranulated mast cells, and peptides corresponding to the tethered ligand domains of PAR-1 and
PAR-2
increased [Ca2+]i in > 50 % of cultured myenteric neurons. Approximately 60 % of neurons that responded to PAR-1 agonists responded to
PAR-2
agonists, and > 90 % of PAR-1 and
PAR-2
responsive neurons responded to ATP. 4. These results indicate that a large proportion of myenteric neurons that express excitatory and inhibitory neurotransmitters and purinoceptors also express PAR-1 and
PAR-2
. Thrombin and tryptase may excite myenteric neurons during trauma and inflammation when prothrombin is activated and mast cells degranulate. This novel action of serine proteases probably contributes to abnormal neurotransmission and motility in the inflamed intestine.
...
PMID:Thrombin and mast cell tryptase regulate guinea-pig myenteric neurons through proteinase-activated receptors-1 and -2. 1035 15
We have investigated the ability of protease-activated receptor-1 (PAR-1),
PAR-2
, PAR-3 and PAR-4 agonists to induce contractile responses in isolated guinea-pig gallbladder. Thrombin, trypsin, mouse PAR-1 activating (SFLLRN-NH(2)) peptide, and mouse
PAR-2
activating (SLIGRL-NH(2)) and human
PAR-2
activating (SLIGKV-NH(2)) peptides produced a concentration-dependent contractile response. Mouse PAR-4 activating (GYPGKF-NH(2)) peptide, the mouse PAR-1 reverse (NRLLFS-NH(2)) peptide, the mouse
PAR-2
reverse (LRGILS-NH(2)) and human
PAR-2
reverse (VKGILS-NH(2)) peptides caused negligible contractile responses at the highest concentrations tested. An additive effect was observed following the contractile response induced by either trypsin or thrombin, with the addition of a different PAR agonist (SFLLRN-NH(2) and SLIGRL-NH(2), respectively). Desensitization to
PAR-2
activating peptide attenuated the response to trypsin but failed to attenuate the response to PAR-1 agonists, and conversely desensitization to PAR-1 attenuated the response to thrombin but failed to alter contractile responses to
PAR-2
agonists. The contractile responses produced by thrombin, trypsin, SFLLRN-NH(2) and SLIGRL-NH(2) were markedly reduced in the presence of the cyclo-oxygenase inhibitor, indomethacin, whilst the small contractile response produced by NRLLFS-NH(2) and LRGILS-NH(2) were insensitive to indomethacin. The contractile responses to thrombin, trypsin, SFLLRN-NH(2) and SLIGRL-NH(2) were unaffected by the presence of: the non-selective muscarinic antagonist, atropine; the nitric oxide synthase inhibitor, L-NAME; the sodium channel blocker, tetrodotoxin; the combination of selective
tachykinin
NK(1) and NK(2) receptor antagonists, (S)-1-[2-[3-(3,4-dichlorphenyl)-1 (3-isopropoxyphenylacetyl) piperidin-3-yl] ethyl]-4-phenyl-1 azaniabicyclo [2.2.2] octane chloride (SR140333) and (S)-N-methyl-N-[4-acetylamino-4-phenylpiperidino-2-(3, 4-dichlorophenyl)-butyl] benzamide (SR48968), respectively. The results indicate that PAR-1 and
PAR-2
activation causes contractile responses in the guinea-pig gallbladder, an effect that is mediated principally by prostanoid release, and is independent of neural mechanisms.
...
PMID:Evidence that PAR-1 and PAR-2 mediate prostanoid-dependent contraction in isolated guinea-pig gallbladder. 1103 Jul 17
There is increasing evidence that the cutaneous nervous system modulates physiological and pathophysiological effects including cell growth and differentiation, immunity and inflammation as well as tissue repair. Both cutaneous nervous fibers and inflammatory cells are able to release neuromediators and thereby activate specific receptors on target cells in the skin or transient immunocompetent cells. Cutaneous neuromediators include classical neurotransmitters such as catecholamines and acetylcholine being released from the automatic nervous system or cutaneous cells. On the other hand neuropeptides including
substance P
, calcitonin gene related peptide (CRGP), vasointestinal peptide (VIP) or proopiomelanocortin (POMC) derived peptides such as alpha melanocyte stimulating hormone (alphaMSH) may be released from sensory or autonomic nerve fibers and several epidermal as well as dermal cells. Neuropeptides are known to activate a variety of cutaneous cells through high affinity neuropeptide receptors or by direct activation of intracellular G-protein signalling cascades. Via the modulation of transcription factor activation (NF-kappaB, AP-1, STAT-3) they regulate the expression of adhesion molecules and proinflammatory cytokines in different cells and thereby function as modulators of immune and inflammatory reactions. Accordingly, neuropeptides such as CGRP or alphaMSH in vitro were found to downregulate costimulatory molecule expression on dendritic cells and in vivo via the generation of suppressor T-lymphocytes to induce hapten specific tolerance. Proteinases such as tryptase or neural endopeptidase inactivate neuropeptides in the extracellular space or at the cell surface thereby terminating neuropeptide induced inflammatory or immune responses. Proteinase-activated receptors (PAR) are recently described receptors that may have high impact in regulating cutaneous neurogenic inflammation. In the skin
PAR-2
being expressed on sensory neurons and endothelial cells is self activated by tethered peptide ligands that are exposed after extracellular amino-terminal cleavage by trypsin or mast cell tryptase.
PAR-2
agonists were found to induce the release of CGRP and SP which mediate vasodilation, plasma extravasation as well as the expression of adhesion molecules on vascular endothelial cells and thus elicit neurogenic inflammation. These findings indicate that the neuromediator network including neuropeptide receptors as well as proteinases play an important role in the maintenance of tissue integrity and the regulation of inflammatory and immune responses in the skin.
...
PMID:Neuromediators--a crucial component of the skin immune system. 1241 63
Historically, mast cells were known as a key cell type involved in type I hypersensitivity. Until last two decades, this cell type was recognized to be widely involved in a number of non-allergic diseases including inflammatory bowel disease (IBD). Markedly increased numbers of mast cells were observed in the mucosa of the ileum and colon of patients with IBD, which was accompanied by great changes of the content in mast cells such as dramatically increased expression of TNFalpha, IL-16 and
substance P
. The evidence of mast cell degranulation was found in the wall of intestine from patients with IBD with immunohistochemistry technique. The highly elevated histamine and tryptase levels were detected in mucosa of patients with IBD, strongly suggesting that mast cell degranulation is involved in the pathogenesis of IBD. However, little is known of the actions of histamine, tryptase, chymase and carboxypeptidase in IBD. Over the last decade, heparin has been used to treat IBD in clinical practice. The low molecular weight heparin (LMWH) was effective as adjuvant therapy, and the patients showed good clinical and laboratory response with no serious adverse effects. The roles of PGD2, LTC4, PAF and mast cell cytokines in IBD were also discussed. Recently, a series of experiments with dispersed colon mast cells suggested there should be at least two pathways in man for mast cells to amplify their own activation-degranulation signals in an autocrine or paracrine manner. The hypothesis is that mast cell secretogogues induce mast cell degranulation, release histamine, then stimulate the adjacent mast cells or positively feedback to further stimulate its host mast cells through H1 receptor. Whereas released tryptase acts similarly to histamine, but activates mast cells through its receptor
PAR-2
. The connections between current anti-IBD therapies or potential therapies for IBD with mast cells were discussed, implicating further that mast cell is a key cell type that is involved in the pathogenesis of IBD. In conclusion, while pathogenesis of IBD remains unclear, the key role of mast cells in this group of diseases demonstrated in the current review implicates strongly that IBD is a mast cell associated disease. Therefore, close attentions should be paid to the role of mast cells in IBD.
...
PMID:Key role of mast cells and their major secretory products in inflammatory bowel disease. 1476 Jul 48
Inflammatory proteases (mast cell tryptase and trypsins) cleave
protease-activated receptor 2
(
PAR2
) on spinal afferent neurons and cause persistent inflammation and hyperalgesia by unknown mechanisms. We determined whether transient receptor potential vanilloid receptor 1 (TRPV1), a cation channel activated by capsaicin, protons, and noxious heat, mediates
PAR2
-induced hyperalgesia.
PAR2
was coexpressed with TRPV1 in small- to medium-diameter neurons of the dorsal root ganglia (DRG), as determined by immunofluorescence.
PAR2
agonists increased intracellular [Ca2+] ([Ca2+]i) in these neurons in culture, and
PAR2
-responsive neurons also responded to the TRPV1 agonist capsaicin, confirming coexpression of
PAR2
and TRPV1.
PAR2
agonists potentiated capsaicin-induced increases in [Ca2+]i in TRPV1-transfected human embryonic kidney (HEK) cells and DRG neurons and potentiated capsaicin-induced currents in DRG neurons. Inhibitors of phospholipase C and protein kinase C (PKC) suppressed
PAR2
-induced sensitization of TRPV1-mediated changes in [Ca2+]i and TRPV1 currents. Activation of
PAR2
or PKC induced phosphorylation of TRPV1 in HEK cells, suggesting a direct regulation of the channel. Intraplantar injection of a
PAR2
agonist caused persistent thermal hyperalgesia that was prevented by antagonism or deletion of TRPV1. Coinjection of nonhyperalgesic doses of
PAR2
agonist and capsaicin induced hyperalgesia that was inhibited by deletion of TRPV1 or antagonism of PKC.
PAR2
activation also potentiated capsaicin-induced release of
substance P
and calcitonin gene-related peptide from superfused segments of the dorsal horn of the spinal cord, where they mediate hyperalgesia. We have identified a novel mechanism by which proteases that activate
PAR2
sensitize TRPV1 through PKC. Antagonism of
PAR2
, TRPV1, or PKC may abrogate protease-induced thermal hyperalgesia.
...
PMID:Protease-activated receptor 2 sensitizes the capsaicin receptor transient receptor potential vanilloid receptor 1 to induce hyperalgesia. 1512 44
Protease-activated receptors are G protein-coupled receptors activated by serine-proteases. Protease-activated receptor 2 is involved in the regulation of airway smooth muscle tone but its effects vary according to species and experimental conditions. We determined the effects of
protease-activated receptor 2
activation on smooth muscle tone and airway reactivity to histamine in guinea pigs and smoking or non-smoking humans. The effects of trypsin and protease-activated receptor activating peptide on the isometric tension and response to histamine of guinea pig tracheal and human bronchial rings were studied. Human tissues were obtained from 6 smokers and 4 non-smokers. We assessed the effects of epithelial removal, inhibitors of cyclooxygenases, nitric oxide synthases, neutral endopeptidase and antagonists of acetylcholine, histamine, bradykinin and
tachykinin
receptors. Bronchomotor responses to
protease-activated receptor 2
activation were variable in guinea pig, in half of animals PAR2 activation induced smooth muscle relaxation through the epithelial release of prostanoids but not of nitric oxide. In human airways,
protease-activated receptor 2
activation reduced responsiveness to histamine in bronchial rings from smokers but increased responsiveness in bronchi from non-smokers. This study demonstrates an influence of tobacco smoking on the effect of
protease-activated receptor 2
activation on airway responsiveness in humans, with an increased protection against histamine-induced contractions, probably through an increased epithelial release of prostanoids. The role of airway
protease-activated receptor 2
may be to maintain smooth muscle tone homeostasis.
...
PMID:Protease-activated receptor 2 in regulation of bronchomotor tone: effect of tobacco smoking. 1519 59
Activation of protease-activated receptors (PAR) can induce vasodilation (VD) and increase of vascular permeability either directly by stimulating endothelial cells or indirectly via activation of nociceptors and subsequent release of neuropeptides (neurogenic inflammation). We aimed to estimate the relative contribution of the two pathways for stimulation with endogenous activators of
PAR-2
(trypsin) and of PAR-1, 3 and 4 (thrombin) using in vivo dermal microdialysis in rats. Protein extravasation (PE) was assessed by increase of protein concentration in the dialysate, and VD was quantified by laser Doppler scanning. Both trypsin (10(-8)-10(-4) M) and thrombin (10(-6), 10(-5.5) and 10(-5) M) provoked PE and local VD in a dose-dependent manner. Trypsin (10(-4) M)-induced PE was inhibited by 87.2 +/- 21% due to the
substance P
(SP) NK1 receptor antagonist SR140333. VD was blocked by 58.15 +/- 10.1% in response to the calcitonin gene-related peptide (CGRP) receptor antagonist CGRP(8-37). By contrast, CGRP(8-37) did not affect thrombin-induced VD, while blockade of SP receptors prevented the PE elicited only by low doses of thrombin (10(-6) M), being ineffective at higher thrombin concentrations. In conclusion, intradermal trypsin elicits a neurogenic inflammation in rat, probably mediated via
PAR-2
activation on nociceptors and subsequent SP and CGRP release. Thrombin-induced PE and VD are mediated mainly by a non-neurogenic mechanism.
...
PMID:Neurogenic components of trypsin- and thrombin-induced inflammation in rat skin, in vivo. 1636 32
Exacerbated sensitivity to mechanical stimuli that are normally innocuous or mildly painful (mechanical allodynia and hyperalgesia) occurs during inflammation and underlies painful diseases. Proteases that are generated during inflammation and disease cleave
protease-activated receptor 2
(
PAR2
) on afferent nerves to cause mechanical hyperalgesia in the skin and intestine by unknown mechanisms. We hypothesized that
PAR2
-mediated mechanical hyperalgesia requires sensitization of the ion channel transient receptor potential vanilloid 4 (TRPV4). Immunoreactive TRPV4 was coexpressed by rat dorsal root ganglia (DRG) neurons with
PAR2
,
substance P
(SP) and calcitonin gene-related peptide (CGRP), mediators of pain transmission. In
PAR2
-expressing cell lines that either naturally expressed TRPV4 (bronchial epithelial cells) or that were transfected to express TRPV4 (HEK cells), pretreatment with a
PAR2
agonist enhanced Ca2+ and current responses to the TRPV4 agonists phorbol ester 4alpha-phorbol 12,13-didecanoate (4alphaPDD) and hypotonic solutions.
PAR2
-agonist similarly sensitized TRPV4 Ca2+ signals and currents in DRG neurons. Antagonists of phospholipase Cbeta and protein kinases A, C and D inhibited
PAR2
-induced sensitization of TRPV4 Ca2+ signals and currents. 4alphaPDD and hypotonic solutions stimulated SP and CGRP release from dorsal horn of rat spinal cord, and pretreatment with
PAR2
agonist sensitized TRPV4-dependent peptide release. Intraplantar injection of
PAR2
agonist caused mechanical hyperalgesia in mice and sensitized pain responses to the TRPV4 agonists 4alphaPDD and hypotonic solutions. Deletion of TRPV4 prevented
PAR2
agonist-induced mechanical hyperalgesia and sensitization. This novel mechanism, by which
PAR2
activates a second messenger to sensitize TRPV4-dependent release of nociceptive peptides and induce mechanical hyperalgesia, may underlie inflammatory hyperalgesia in diseases where proteases are activated and released.
...
PMID:Protease-activated receptor 2 sensitizes the transient receptor potential vanilloid 4 ion channel to cause mechanical hyperalgesia in mice. 1718 31
Activation of the
protease-activated receptor 2
(
PAR2
) or the transient receptor potential vanilloid type 1 (TRPV1) channels expressed in cardiac sensory afferents containing calcitonin gene-related peptide (CGRP) and/or
substance P
(SP) has been proposed to play a protective role in myocardial ischemia-reperfusion (I/R) injury. However, the interaction between
PAR2
and TRPV1 is largely unknown. Using gene-targeted TRPV1-null mutant (TRPV1(-/-)) or wild-type (WT) mice, we test the hypothesis that TRPV1 contributes to
PAR2
-mediated cardiac protection via increasing the release of CGRP and SP. Immunofluorescence labeling showed that TRPV1 coexpressed with
PAR2
, PKC-epsilon, or PKAc in cardiomyocytes, cardiac blood vessels, and perivascular nerves in WT but not TRPV1(-/-) hearts. WT or TRPV1(-/-) hearts were Langendorff perfused with the selective
PAR2
agonist, SLIGRL, in the presence or absence of various antagonists, followed by 35 min of global ischemia and 40 min of reperfusion (I/R). The recovery rate of coronary flow, the maximum rate of left ventricular pressure development, left ventricular end-diastolic pressure, and left ventricular developed pressure were evaluated after I/R. SLIGRL improved the recovery of hemodynamic parameters, decreased lactate dehydrogenase release, and reduced the infarct size in both WT and TRPV1(-/-) hearts (P < 0.05). The protection of SLIGRL was significantly surpassed for WT compared with TRPV1(-/-) hearts (P < 0.05). CGRP(8-37), a selective CGRP receptor antagonist, RP67580, a selective neurokinin-1 receptor antagonist, PKC-epsilon V1-2, a selective PKC-epsilon inhibitor, or H-89, a selective PKA inhibitor, abolished SLIGRL protection by inhibiting the recovery of the rate of coronary flow, maximum rate of left ventricular pressure development, and left ventricular developed pressure, and increasing left ventricular end-diastolic pressure in WT but not TRPV1(-/-) hearts. Radioimmunoassay showed that SLIGRL increased the release of CGRP and SP in WT but not TRPV1(-/-) hearts (P < 0.05), which were prevented by PKC-epsilon V1-2 and H-89. Thus our data show that
PAR2
activation improves cardiac recovery after I/R injury in WT and TRPV1(-/-) hearts, with a greater effect in the former, suggesting that
PAR2
-mediated protection is TRPV1 dependent and independent, and that dysfunctional TRPV1 impairs
PAR2
action.
PAR2
activation of the PKC-epsilon or PKA pathway stimulates or sensitizes TRPV1 in WT hearts, leading to the release of CGRP and SP that contribute, at least in part, to
PAR2
-induced cardiac protection against I/R injury.
...
PMID:Protease-activated receptor 2-mediated protection of myocardial ischemia-reperfusion injury: role of transient receptor potential vanilloid receptors. 1981 53
Inflammation is associated with various pulmonary diseases and contributes to the pathogenesis of acute lung injury. We previously identified a proinflammatory signaling pathway triggered by G protein-coupled receptors (GPCRs) in which stimulation of G(q)-coupled GPCRs results in activation of the transcription factor NF-kappaB. Because damage to the lung causes the release of multiple mediators acting through G(q)-coupled GPCRs, this signaling pathway is likely to contribute to inflammatory processes in the injured lung. In an effort to identify novel inhibitors of lung inflammation, the National Institutes of Health Clinical Collection, a library of 446 compounds, was screened for inhibitory activity toward production of IL-8 induced by stimulation of the G(q)-coupled
tachykinin 1
receptor with
substance P
in A549 cells. Twenty-eight compounds that significantly inhibited
substance P
-induced IL-8 production were identified. The most potent inhibitor was triptolide, a diterpenoid compound from Tripterygium wilfordii Hook F, a vine used in traditional Chinese medicine for the treatment of autoimmune diseases. Triptolide inhibited IL-8 production induced by
substance P
with an IC(50) of 2.3 x 10(-8) M and inhibited NF-kappaB activation in response to an agonist of the
protease-activated receptor 2
with an IC(50) of 1.4 x 10(-8) M. Anti-inflammatory effects of triptolide were assessed in vivo using a chlorine gas lung injury model in mice. Triptolide inhibited neutrophilic inflammation and the production of KC (Cxcl1) in the lungs of chlorine-exposed mice. The results demonstrate that triptolide exhibits anti-inflammatory activity in cultured lung cells and in an in vivo model of acute lung injury.
...
PMID:Identification of triptolide, a natural diterpenoid compound, as an inhibitor of lung inflammation. 2034 78
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