Rat proteinase-activated receptor-2 (PAR-2): cDNA sequence and activity of receptor-derived peptides in gastric and vascular tissue
Rat proteinase-activated receptor-2 (PAR-2): cDNA sequence and activity of receptor-derived peptides in gastric and vascular tissue
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DOI：
10.1111/j.1476-5381.1996.tb15433.x
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发表时间：
1996-06-01
影响因子：
7.3
通讯作者：
Hollenberg, MD
中科院分区：
文献类型：
--
作者：
Saifeddine, M;AlAni, B;Hollenberg, MD
1蛋白酶激活受体2（PAR-2）衍生肽的生物活性，在小鼠和大鼠胃纵肌（LM）组织和大鼠主动脉环制备物中测量SLIGRL（PP 6）、SLIGRL-NH 2（PP 6-NH 2）和SLIGR-NH 2（PP 5-NH 2），并观察PAR-2-将衍生的肽与胰蛋白酶和凝血酶受体活化肽SFLLR-NH 2（TP 5-NH 2）的作用进行比较。2从新生大鼠肠cDNA文库，以及从肠和肾衍生的cDNA，对大鼠PAR-2受体的编码区进行克隆和测序，从而确定其与先前描述的小鼠PAR-2受体的紧密序列同一性;这些信息沿着逆转录酶（RT）聚合酶链反应（PCR）分析来自胃和主动脉组织的cDNA，以确定PAR-1的同时存在。在小鼠和大鼠胃制备物中，PAR-2衍生的多肽PP 6、PP 6-HN 2和PP 5-NH 2引起的收缩反应模拟了低浓度胰蛋白酶的收缩作用（5 u/ml（-1）;大鼠LM组织累积暴露于PP 6-NH 2导致对该多肽的收缩反应脱敏，但不导致对TP 5-NH 2的收缩反应脱敏，反之亦然，从而表明在对PAR-2和凝血酶受体衍生肽有反应的受体之间缺乏交叉脱敏。在大鼠胃制备物中，PAR-2激活肽的效力低于TP 5-NH 2的效力（效力顺序：TPS-MH（2）>> PP 6-NH 2大于或等于PP 6> PP 5-NH 2）; PP 6在该实验中是一种部分激动剂。6大鼠胃制剂中PP 6和PP 6-NH 2的收缩作用需要细胞外钙的存在，被硝苯地平抑制，并被环氧合酶抑制剂阻断，吲哚美辛和酪氨酸激酶抑制剂染料木黄酮，但不被激酶C抑制剂GF 109203 X。阿托品、扑尔敏、酚苄明、普萘洛尔、利坦色林或河豚毒素均不能阻断收缩反应。7在内皮完整的大鼠主动脉环预收缩标本中，所有PAR-2衍生肽均引起迅速舒张反应，该反应可被一氧化氮合酶抑制剂N-ω-硝基-L-精氨酸甲酯（L-NAME）阻断，但不被D-NAME阻断;在具有PAR-2和凝血酶受体mRNA的无内皮制备物中，PAR-2活化肽既不引起松弛也不引起收缩，与TP 5-NH 2的收缩作用相反。阿托品、扑尔敏、染料木素、吲哚美辛、普萘洛尔或利坦色林不能阻断对PP 6-NH 2的舒张反应。8在大鼠主动脉制备物中，PP 6、PP 6-NH 2和PP 5-NH 2的效力大于凝血酶受体活化肽TP 5-NH 2的效力（效力顺序：PP 6-NH 2大于或等于PP 6> PP 5-NH 2> TP 5-NH 2）。9在大鼠主动脉制备物中，PAR-2衍生肽的舒张作用由胰蛋白酶模拟，浓度为（0.5-1 μ ml（-1）; 1-2 nM）。10用PAR-2肽和胰蛋白酶获得的生物测定数据，沿着分子克隆/RT-PCR分析，表明存在功能性PAR-2受体，其可以激活胃和血管平滑肌制剂中的不同反应。这些反应与相同组织中凝血酶受体活化所产生的反应相当，从而表明PAR-2活化肽的受体可能发挥与凝血酶受体一样深远的生理作用。
1 The biological activities of the proteinase-activated receptor number 2 (PAR-2)-derived peptides, SLIGRL (PP6) SLIGRL-NH2 (PP6-NH2) and SLIGR-NH2 (PP5-NH2) were measured in mouse and rat gastric longitudinal muscle (LM) tissue and in a rat aortic ring preparation and the actions of the PAR-2-derived peptides were compared with trypsin and with the actions of the thrombin receptor activating peptide, SFLLR-NH2 (TP5-NH2).2 From a neonatal rat intestinal cDNA library, and from intestinal and kidney-derived cDNA, the coding region of the rat PAR-2 receptor was cloned and sequenced, thereby establishing its close sequence identity with the previously described mouse PAR-2 receptor; and this information, along with a reverse-transcriptase (RT) polymerase chain reaction (PCR) analysis of cDNA derived from gastric and aortic tissue was used to establish the concurrent presence of PAR-2 and thrombin receptor mRNA in both tissues.3 In the mouse and rat gastric preparations, the PAR-2-derived polypeptides, PP6, PP6-HN2 and PP5-NH2 caused contractile responses that mimicked the contractile actions of low concentrations of trypsin (5 u/ml(-1); 10 nM) and that were equivalent to contractions caused by TP5-NH2.4 The cumulative exposure of the rat LM tissue to PP6-NH2 led to a desensitization of the contractile response to this polypeptide, but not to TP5-NH2 and vice versa, so as to indicate a lack of cross-desensitization between the receptors responsive to the PAR-2 and thrombin receptor-derived peptides.5 In the rat gastric preparation, the potencies of the PAR-2-activating peptides were lower than the potency of TP5-NH2 (potency order: TPS-MH(2)>>PP6-NH2 greater than or equal to PP6>PP5-NH2); PP6 was a partial agonist in this preparation.6 The contractile actions of PP6 and PP6-NH2 in the rat gastric preparation required the presence of extracellular calcium, were inhibited by nifedipine and were blocked by the cyclo-oxygenase inhibitor, indomethacin and by the tyrosine kinase inhibitor, genistein, but not by the kinase C inhibitor, GF109203X. The contractile responses were not blocked by atropine, chlorpheniramine, phenoxybenzamine, propranolol, ritanserin or tetrodotoxin.7 In a precontracted rat aortic ring preparation, with an intact endothelium, all of the PAR-2-derived peptides caused a prompt relaxation response that was blocked by the nitric oxide synthase inhibitor, N-omega-nitro-L-arginine-methyl ester (L-NAME) but not by D-NAME; in an endothelium-free preparation, which possessed mRNA for both the PAR-2 and thrombin receptors, the PAR-2-activating peptides caused neither a relaxation nor a contraction, in contrast with the contractile action of TP5-NH2. The relaxation response to PP6-NH2 was not blocked by atropine, chlorpheniramine, genistein, indomethacin, propranolol or ritanserin.8 In the rat aortic preparation, the potencies of PP6, PP6-NH2 and PP5-NH2 were greater than those of the thrombin receptor activating peptide, TP5-NH2 (potency order: PP6-NH2 greater than or equal to PP6>PP5-NH2>TP5-NH2).9 In the rat aortic preparation, the relaxant actions of the PAR-2-derived peptides were mimicked by trypsin, at concentrations (0.5-1 u ml(-1); 1-2 nM) lower than those that can activate the thrombin receptor.10 The bioassay data obtained with the PAR-2 peptides and with trypsin, along with the molecular cloning/RT-PCR analysis, point to the presence of functional PAR-2 receptors that can activate distinct responses in the gastric and vascular smooth muscle preparations. These responses were comparable to those resulting from thrombin receptor activation in the same tissues, so as to suggest that the receptor for the PAR-2-activating peptides may play a physiological role as far reaching as the one proposed for the thrombin receptor.