Pivotal Role of Mouse Mast Cell Protease 4 in the Conversion and Pressor Properties of Big-Endothelin-1
Pivotal Role of Mouse Mast Cell Protease 4 in the Conversion and Pressor Properties of Big-Endothelin-1
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DOI：
10.1124/jpet.112.202275
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发表时间：
2013-07-01
影响因子：
3.5
通讯作者：
D'Orleans-Juste, Pedro
中科院分区：
文献类型：
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作者：
Houde, Martin;Jamain, Marc-David;D'Orleans-Juste, Pedro
据报道，丝氨酸蛋白酶糜酶从Ang-I产生心内血管紧张素-II（Ang-II）以及从Big-ET-1产生内皮素-1（ET-1）的中间前体ET-1（1-31）。尽管人类只有一种糜酶，但有记录表明有几种小鼠同工型，每种都有自己特定的催化活性。其中，小鼠肥大细胞蛋白酶4（mMCP-4）是其活性与人糜酶最相似的同种型。本研究的目的是在体外和小鼠模型中表征mMCP-4将Big-ET-1转化为其生物活性代谢产物ET-1的能力。基础平均动脉压在野生型（WT）和mMCP-4（-/-）小鼠之间没有差异。全身给予Big-ET-1触发了升压反应，并增加了免疫反应性（IR）ET-1（1-31）和ET-1的血液水平，与WT对照组相比，mMCP-4敲除（-/-）小鼠中ET-1的血液水平降低了50%以上。mMCP-4（-/-）小鼠中对Big-ET-1的残留反应对脑啡肽酶/中性内肽酶抑制剂thiorphan和特异性糜酶抑制剂TY-51469 {2-[4-（5-氟-3-甲基苯并[B]噻吩-2-基）磺酰胺基-3-甲磺酰基苯基]噻唑-4-羧酸}不敏感。通过高效液相色谱/基质辅助激光解吸/电离质谱法检测，WT小鼠（而非mMCP-4（-/-）小鼠）的肺、左心室、主动脉和肾脏的可溶性组分以TY-51469敏感的方式从外源性Big-ET-1产生ET-1（1-31）。最后，与WT小鼠相比，来自mMCP-4（-/-）小鼠的组织中IR-ET-1的肺内源性水平降低了40%以上。我们的研究结果表明，在小鼠模型中，mMCP-4在全身性Big-ET-1向ET-1的动态转化中起关键作用。
The serine protease chymase has been reported to generate intracardiac angiotensin-II (Ang-II) from Ang-I as well as an intermediate precursor of endothelin-1 (ET-1), ET-1 (1-31) from Big-ET-1. Although humans possess only one chymase, several murine isoforms are documented, each with its own specific catalytic activity. Among these, mouse mast cell protease 4 (mMCP-4) is the isoform most similar to the human chymase for its activity. The aim of this study was to characterize the capacity of mMCP-4 to convert Big-ET-1 into its bioactive metabolite, ET-1, in vitro and in vivo in the mouse model. Basal mean arterial pressure did not differ between wild-type (WT) and mMCP-4(-/-) mice. Systemic administration of Big-ET-1 triggered pressor responses and increased blood levels of immunoreactive (IR) ET-1 (1-31) and ET-1 that were reduced by more than 50% in mMCP-4 knockout (-/-) mice compared with WT controls. Residual responses to Big-ET-1 in mMCP-4(-/-) mice were insensitive to the enkephalinase/neutral endopeptidase inhibitor thiorphan and the specific chymase inhibitor TY-51469 {2-[4-(5-fluoro-3-methylbenzo[b]thiophen-2-yl)sulfonamido-3-methanesulfonylphenyl]thiazole-4-carboxylic acid}. Soluble fractions from the lungs, left cardiac ventricle, aorta, and kidneys of WT but not mMCP-4(-/-) mice generated ET-1 (1-31) from exogenous Big-ET-1 in a TY-51469-sensitive fashion as detected by high-performance liquid chromatography/matrix-assisted laser desorption/ionization-mass spectrometry. Finally, pulmonary endogenous levels of IR-ET-1 were reduced by more than 40% in tissues derived from mMCP-4(-/-) mice compared with WT mice. Our results show that mMCP-4 plays a pivotal role in the dynamic conversion of systemic Big-ET-1 to ET-1 in the mouse model.