THROMBIN STIMULATES PROLIFERATION OF CULTURED RAT AORTIC SMOOTH-MUSCLE CELLS BY A PROTEOLYTICALLY ACTIVATED RECEPTOR
THROMBIN STIMULATES PROLIFERATION OF CULTURED RAT AORTIC SMOOTH-MUSCLE CELLS BY A PROTEOLYTICALLY ACTIVATED RECEPTOR
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DOI：
10.1172/jci116206
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发表时间：
1993-01-01
影响因子：
15.9
通讯作者：
OWENS, GK
中科院分区：
文献类型：
--
作者：
MCNAMARA, CA;SAREMBOCK, IJ;OWENS, GK
凝血酶与刺激平滑肌细胞 (SMC) 增殖有关，从而导致血管成形术后再狭窄。目前的研究表明，人 α-凝血酶对于培养的大鼠主动脉 SMC 来说是一种强效且有效的有丝分裂原，刺激 H-3-胸苷掺入的增加，以及在 1 至 10 nM 浓度下细胞数量的增加。 γ-凝血酶具有酶活性，但缺乏纤维蛋白原凝血活性，可刺激 SMC 有丝分裂，但其效力比 α-凝血酶低约 10 倍。相反，D-苯丙氨酰-L-丙基-L-精氨酰-氯甲基酮-α-凝血酶缺乏酶活性，没有促有丝分裂作用。二异丙基氟磷酸-α-凝血酶不能刺激有丝分裂，除非其酶活性与α-凝血酶在其有丝分裂阈值时具有相同的酶活性。因此，凝血酶诱导的增殖依赖于酶活性。对应于人凝血酶受体的氨基酸42至55的14残基肽(SFLLRNPNDKYEPF)(Vu，T.K.，D.T.Hung，V.1.Wheaton，和S.R.Coughlin，1991.Cell.64：1057-1068)在刺激SMC增殖方面具有完全功效。反转该肽的前两个氨基酸可消除促有丝分裂活性。 Northern 分析表明 SMC 表达与标记的凝血酶受体 cDNA 探针杂交的单一 mRNA 种类。这些发现表明，α-凝血酶通过与先前鉴定的受体非常相似或相同的受体的蛋白水解激活来刺激 SMC 增殖。
Thrombin has been implicated in the stimulation of smooth muscle cell (SMC) proliferation that contributes to post angioplasty restenosis. The present studies demonstrated that human alpha-thrombin was a potent and efficacious mitogen for cultured rat aortic SMC, stimulating an increase in H-3-thymidine incorporation, as well as an increase in cell number at 1 to 10 nM concentration. gamma-Thrombin, which is enzymatically active but lacks fibrinogen clotting activity, stimulated SMC mitogenesis but was approximately 10-fold less potent than alpha-thrombin. In contrast, D-phenylalanyl-L-propyl-L-arginyl-chloromethyl ketone-alpha-thrombin, which lacked enzymatic activity, had no mitogenic effect. Diisopropylfluorophosphate-alpha-thrombin failed to stimulate mitogenesis except at concentrations having equivalent enzymatic activity as that of alpha-thrombin at its threshold for mitogenesis. Thus, thrombin-induced proliferation was dependent on enzymatic activity. A 14-residue peptide (SFLLRNPNDKYEPF) corresponding to amino acids 42 through 55 of the human thrombin receptor (Vu, T. K., D. T. Hung, V. 1. Wheaton, and S. R. Coughlin, 1991. Cell. 64:1057-1068) had full efficacy in stimulating SMC proliferation. Reversing the first two amino acids of this peptide abolished mitogenic activity. Northern analysis demonstrated that SMC expressed a single mRNA species that hybridized to a labeled thrombin receptor cDNA probe. These findings indicate that a-thrombin stimulates SMC proliferation via the proteolytic activation of a receptor very similar or identical to that previously identified.