Detection of functional receptors for the proteinase-activated-receptor-2-activating polypeptide, SLIGRL-NH<sub>2</sub>, in rat vascular and gastric smooth muscle

Al-Ani, Bahjaf; Saifeddine, Mahmoud; Hollenberg, Morley D.

doi:10.1139/y95-172

Cited by 156 publications

(142 citation statements)

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“…Aorta Ring Relaxation Assays Using Rat and Murine Vascular Tissue-Activation of either PAR 1 or PAR 2 (46,52) but not PAR 4 (49) induces an endothelium-dependent, nitric oxidemediated relaxation of rat or mouse aorta. To determine whether hKs could activate PARs in intact tissues, which unlike the cells may contain extracellular proteinase inhibitors in vivo, we examined the actions of the hKs in rat and murine aorta preparations.…”

Section: Vascular Bioassaysmentioning

confidence: 98%

“…Aorta Relaxation Assay-The endothelium-intact rat and murine aortic ring assay used to monitor the responses to the PAR-activating peptides and the kallikreins was essentially the same as that described previously for measuring the actions of PAR 2 -activating peptides (46,47). In brief, male Sprague-Dawley rats (250 -300 g) or male C57/Bl6 mice (either wild-type or PAR 2 null, about 50 -70 g), cared for in accordance with the Guidelines of the Canadian Council on Animal Care, were killed by cervical dislocation.…”

Section: Bioassay Proceduresmentioning

confidence: 99%

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Proteinase-activated Receptors, Targets for Kallikrein Signaling

Οικονομοπούλου

Hansen

Saifeddine

et al. 2006

Journal of Biological Chemistry

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Serine proteinases like thrombin can signal to cells by the cleavage/activation of proteinase-activated receptors (PARs).Although thrombin is a recognized physiological activator of PAR 1 and PAR 4 , the endogenous enzymes responsible for activating PAR 2 in settings other than the gastrointestinal system, where trypsin can activate PAR 2 , are unknown. We tested the hypothesis that the human tissue kallikrein (hK) family of proteinases regulates PAR signaling by using the following: 1) a high pressure liquid chromatography (HPLC)-mass spectral analysis of the cleavage products yielded upon incubation of hK5, -6, and -14 with synthetic PAR N-terminal peptide sequences representing the cleavage/activation motifs of PAR 1 , PAR 2 , and PAR 4 ; 2) PAR-dependent calcium signaling responses in cells expressing PAR 1 , PAR 2 , and PAR 4 and in human platelets; 3) a vascular ring vasorelaxation assay; and 4) a PAR 4 -dependent rat and human platelet aggregation assay. We found that hK5, -6, and -14 all yielded PAR peptide cleavage sequences consistent with either receptor activation or inactivation/disarming. Furthermore, hK14 was able to activate PAR 1 , PAR 2 , and PAR 4 and to disarm/inhibit PAR 1 . Although hK5 and -6 were also able to activate PAR 2 , they failed to cause PAR 4 -dependent aggregation of rat and human platelets, although hK14 did. Furthermore, the relative potencies and maximum effects of hK14 and -6 to activate PAR 2 -mediated calcium signaling differed. Our data indicate that in physiological settings, hKs may represent important endogenous regulators of the PARs and that different hKs can have differential actions on PAR 1 , PAR 2 , and PAR 4 . Proteinase-activated receptors (PAR 1-4 )3 compose a unique family of four G-protein-coupled cell surface receptors for certain proteinases (1-9). Proteolytic cleavage within the extracellular N terminus reveals a tethered ligand that binds to the extracellular receptor domains to initiate cell signaling (5, 6, 9, 10). Proteinases that activate PARs include coagulation factors, enzymes from inflammatory cells, and proteinases from epithelial cells and neurons. These enzymes, generated and released during injury and inflammation, can cleave and activate PARs on many cell types from a variety of species (humans, rats, and mice) to regulate the critically important processes of hemostasis, inflammation, pain, and tissue repair. Other proteinases that cleave PARs downstream of the N-terminal tethered ligand sequence disable the receptors for further proteolytic activation, thus abrogating PAR signaling. It is of considerable interest to identify the proteinases that activate and/or disable PARs, in view of the emerging role that these receptors can play in diseases such as asthma, arthritis, inflammatory bowel disease, and cancer (5-7).In some systems, the proteinases that activate PARs have been established. For example, in the circulatory system, PAR 1 , PAR 3 , and PAR 4 are recognized physiological targets for thrombin (4), which does not efficiently acti...

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Section: Vascular Bioassaysmentioning

confidence: 98%

Section: Bioassay Proceduresmentioning

confidence: 99%

Proteinase-activated Receptors, Targets for Kallikrein Signaling

Οικονομοπούλου

Hansen

Saifeddine

et al. 2006

Journal of Biological Chemistry

Self Cite

228

206

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“…The PAR-2-mediated regulation of vascular tone also varies with species and type of blood vessel, as observed with PAR-1. A PAR-2-mediated endothelium-dependent relaxation has been widely reported (23,73,(102)(103)(104)(105), while an endotheliumdependent contraction (104,106) and a direct contractile effect on smooth muscle (81) were also reported. In the porcine coronary artery, thrombin induces only endothelium-dependent relaxation while having no direct effect on smooth muscle (101).…”

Section: Endothelium-dependent Regulation Of Vascular Tone By Thrombimentioning

confidence: 99%

Role of Protease-activated Receptors in the Vascular System

Hirano

Kobayashi

2003

JAT

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“…11 Also, more recent findings indicate that endothelial cells express PAR-2 [12][13][14] and that activation of PAR-2 by SLIGRL and trypsin in isolated segments of peripheral arteries also produces endothelium-dependent vascular relaxation. 6 -9,12 The peptide sequence SLIGRL is identical to that of the native tethered ligand of the new amino terminus of PAR-2 in the mouse and the rat, which is exposed on proteolytic cleavage of the PAR-2 exodomain.…”

Section: Functional Importance Of Par-2mentioning

confidence: 99%

Activation of Protease-Activated Receptor-2 (PAR-2) Elicits Nitric Oxide–Dependent Dilatation of the Basilar Artery In Vivo

Sobey

Cocks

1998

Stroke

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Background and Purpose-Protease-activated receptors (PARs) are a family of G-protein-coupled receptors activated by a tethered ligand amino acid sequence within the amino terminal that is revealed by site-specific proteolysis. In the vascular endothelium, activation of PAR-2 by treatment with trypsin or by using the amino acid ligand sequence (SLIGRL) produces endothelium-dependent relaxation of isolated noncerebral vascular segments. In this study, we first tested whether PAR-2 activation produces cerebral vasodilatation in vivo and then examined whether PAR-2-mediated vasodilatation is dependent on the production of nitric oxide. Methods-Concentration-dependent vasodilator effects of the PAR-2 agonist peptide SLIGRL and trypsin were examined on the basilar artery using a cranial window in anesthetized rats. In addition, the vasodilator effects of SLIGRL, acetylcholine (ACh), and sodium nitroprusside (SNP) were examined in the absence and presence of mol/L) and trypsin (0.01 to 10 U/mL) produced concentration-dependent vasodilator responses. In time-control experiments, SLIGRL (3ϫ10 -6 and 10 -5 mol/L), ACh (10 -6 and 10 -5 mol/L), and SNP (10 -8 and 10 -7 mol/L) elicited reproducible dilatation of the basilar artery. In another group of rats, L-NNA (10 -4 mol/L) markedly inhibited dilator responses to both SLIGRL (13Ϯ3% versus 1Ϯ1% and 39Ϯ7% versus 11Ϯ2%; both PϽ0.05) and ACh (8Ϯ1% versus 0Ϯ0% and 13Ϯ2% versus 3Ϯ1%; both PϽ0.05). By contrast, responses to SNP were significantly augmented after treatment with L-NNA (PϽ0.05 versus control), indicating that inhibitory effects of L-NNA were specific for responses mediated by endogenous nitric oxide. Furthermore, in another group ODQ (10 Ϫ5 mol/L) inhibited responses to SLIGRL to a degree similar to that seen with L-NNA, consistent with a mechanism of PAR-2-mediated vasodilatation that involves activation of guanylate cyclase by nitric oxide. Conclusions-To the best of our knowledge, this study is the first to examine whether PAR-2-mediated vasodilatation is functional in cerebral arteries and is also the first to directly assess the effects of PAR-2 activation on vascular tone in vivo. The results suggest that activation of PAR-2 is an effective and powerful vasodilator mechanism in cerebral arteries in vivo. Cerebral vasodilator responses to PAR-2 activation are mediated by nitric oxide and are likely to be endothelium dependent.

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Detection of functional receptors for the proteinase-activated-receptor-2-activating polypeptide, SLIGRL-NH₂, in rat vascular and gastric smooth muscle

Cited by 156 publications

References 14 publications

Proteinase-activated Receptors, Targets for Kallikrein Signaling

Proteinase-activated Receptors, Targets for Kallikrein Signaling

Role of Protease-activated Receptors in the Vascular System

Activation of Protease-Activated Receptor-2 (PAR-2) Elicits Nitric Oxide–Dependent Dilatation of the Basilar Artery In Vivo

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Detection of functional receptors for the proteinase-activated-receptor-2-activating polypeptide, SLIGRL-NH2, in rat vascular and gastric smooth muscle

Cited by 156 publications

References 14 publications

Proteinase-activated Receptors, Targets for Kallikrein Signaling

Proteinase-activated Receptors, Targets for Kallikrein Signaling

Role of Protease-activated Receptors in the Vascular System

Activation of Protease-Activated Receptor-2 (PAR-2) Elicits Nitric Oxide–Dependent Dilatation of the Basilar Artery In Vivo

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Detection of functional receptors for the proteinase-activated-receptor-2-activating polypeptide, SLIGRL-NH₂, in rat vascular and gastric smooth muscle