Human endothelial cell storage granules: a novel intracellular site for isoforms of the endothelin-converting enzyme.
Human endothelial cell storage granules: a novel intracellular site for isoforms of the endothelin-converting enzyme.
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人内皮细胞储存颗粒：内皮素转换酶亚型的新细胞内位点。
DOI：
10.1161/01.res.83.3.314
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发表时间：
1998
影响因子：
20.1
通讯作者：
Anthony P. Davenport
中科院分区：
文献类型：
--
作者：
Fraser D. Russell;J. Skepper;Anthony P. Davenport
我们之前已经在韦贝尔-帕拉德体中显示了内皮素（ET）样免疫反应染色，储存颗粒是内皮细胞调节分泌途径的一个组成部分。这些结构在化学或机械刺激导致胞质钙内流后脱粒。因此，我们通过测定内皮素转换酶(ECE)-1的超微结构定位，研究了受调节的通路是否可能是参与大ET-1裂解为生物活性肽ET-1的细胞内位点。扫描电镜观察到人脐静脉和冠状动脉内皮细胞表面有低水平的ec样免疫反应性。将外源性大ET-1加入到经透性和未透性培养的人脐静脉内皮细胞中，通过检测培养上清中et样免疫反应性来测定ECE活性。在渗透细胞中观察到ECE活性显著增加，表明ECE也可能在细胞内区室中表达。共聚焦显微镜显示，在人脐静脉内皮细胞核周区和Weibel-Palade小体中，大ET-1和ECE-1的2个亚型（ECE-1 α和ECE-1 β）呈强烈的免疫荧光染色。钙离子载体A23187刺激储存颗粒脱粒，使ET释放到培养上清液中。本研究结果表明，大ET-1被位于内皮储存颗粒内的ECEs加工成成熟的血管活性肽。我们假设这种活性可能在人内皮细胞中调节ET的动员中很重要。
We have previously shown endothelin (ET)-like immunoreactive staining in Weibel-Palade bodies, storage granules that are an integral component of the regulated secretory pathway in endothelial cells. These structures degranulate after chemical or mechanical stimuli that result in cytosolic calcium influx. We therefore investigated whether the regulated pathway might be an intracellular site involved in the cleavage of big ET-1 to the biologically active peptide ET-1 by determining the ultrastructural localization of endothelin-converting enzyme (ECE)-1. A low level of ECE-like immunoreactivity was detected on the cell surface of human umbilical vein and coronary artery endothelial cells by scanning electron microscopy. Exogenous big ET-1 was added to permeabilized and nonpermeabilized cultured human umbilical vein endothelial cells, and ECE activity was measured by the detection of ET-like immunoreactivity in the culture supernatant. A marked increase in ECE activity was observed in permeabilized cells, indicating that ECE may also be expressed in intracellular compartments. Confocal microscopy revealed intense immunofluorescence staining for big ET-1 and the 2 isoforms of ECE-1 (ECE-1alpha and ECE-1beta) in the perinuclear region and in Weibel-Palade bodies of the human umbilical vein endothelial cells. Stimulated degranulation of storage granules by the calcium ionophore A23187 caused release of ET into the culture supernatants. The findings of this study indicate that big ET-1 is processed to the mature vasoactive peptide by ECEs located within endothelial storage granules. We hypothesize that this activity may be important in the regulated mobilization of ET in human endothelial cells.
影响因子：
15.9
作者：
MCEVER, RP;BECKSTEAD, JH;BAINTON, DF
通讯作者：
BAINTON, DF