Stem cell factor and c-kit are expressed by and may affect vascular SMCs through an autocrine pathway
Stem cell factor and c-kit are expressed by and may affect vascular SMCs through an autocrine pathway
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DOI：
10.1016/j.jss.2004.01.005
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发表时间：
2004-08-01
影响因子：
2.2
通讯作者：
Kent, KC
中科院分区：
文献类型：
--
作者：
Hollenbeck, ST;Sakakibara, K;Kent, KC
导论.干细胞因子（SCF）是一种膜结合的可溶性生长因子，可激活c-kit酪氨酸激酶受体。鉴于c-kit和血小板衍生生长因子（PDGF）受体之间的相似性，我们假设SCF/c-kit信号传导与PDGF类似，可能在平滑肌细胞（SMC）功能中起作用，从而在内膜增生的发展中起作用。从旁路移植术时获得的静脉中收获人隐静脉SMC。将在不同时间点球囊损伤的大鼠（n = 12）的颈动脉与假手术对照组（n = 3）进行比较。免疫组化和Western blot检测SCF和c-kit的表达。Western blotting显示人SMC表达膜结合SCF。在单独的实验中，我们发现这种生长因子在暴露于基质金属蛋白酶-9（MMP-9）（一种在动脉损伤时释放的普遍存在的MMP）后经历蛋白水解裂解成其可溶形式。我们接下来评估了人SMC中SCF受体c-kit的表达。人SMC裂解物的蛋白质印迹法显示c-kit的少量但一致的表达。免疫组化证明c-kit表达定位于培养基。为了确定c-kit是否在内膜增生的发展过程中上调，我们在大鼠颈动脉球囊损伤模型中评估了该受体的表达。损伤血管上的IHC染色的定量显示，在损伤后3、7、14和28天，培养基内的c-kit表达显著增加（分别比假手术对照增加28.1、30.8、16和10.4%，P < 0.05）。此外，c-kit表达在新生内膜中显著，并在第7天达到最大值（c-kit阳性面积的53.4 ± 7.8%）。人血管平滑肌细胞表达生长因子SCF及其受体c-kit。SCF通过MMP-9从其膜结合形式释放。这一发现以及在大鼠颈动脉球囊损伤后观察到的c-kit表达的显著增加表明SCF/c-kit信号转导可能通过自分泌途径影响SMC功能。(C)2004爱思唯尔公司All rights reserved.
Introduction. Stem cell factor (SCF) is a membrane-bound and soluble growth factor that activates the c-kit tyrosine kinase receptor. Given the similarities between c-kit and platelet-derived growth factor (PDGF) receptors, we hypothesized that similar to PDGF, SCF/c-kit signaling may play a role in smooth muscle cell (SMC) function and thus the development of intimal hyperplasia.Materials and methods. Human saphenous vein SMCs were harvested from veins procured at the time of bypass grafting. Carotid arteries from rats that were balloon injured (n = 12) at variable time points were compared to sham-operated controls (n = 3). Expression of SCF and c-kit was measured by immunohistochemistry (IHC) and Western blotting.Results. Western blotting revealed that human SMCs express membrane-bound SCF. In separate experiments, we found that this growth factor undergoes proteolytic cleavage to its soluble form following exposure to matrix metalloproteinase-9 (MMP-9), a ubiquitous MMP released at the time of arterial injury. We next evaluated in human SMCs, expression of the SCF receptor, c-kit. Western blotting of human SMC lysates revealed minor but consistent expression of c-kit. IHC demonstrated c-kit expression to be localized to the media. To determine if c-kit is up-regulated during the development of intimal hyperplasia, we evaluated expression of this receptor in a rat carotid balloon injury model. Quantification of IHC staining on injured vessels revealed that c-kit expression within the media was significantly increased at 3, 7, 14, and 28 days following injury (28.1, 30.8, 16, and 10.4% increase over sham controls, respectively, P < 0.05). Furthermore, c-kit expression was prominent within the neointima and maximal at 7 days (53.4 +/- 7.8% of area c-kit positive).Conclusion. Human vascular SMCs express the growth factor SCF and its receptor, c-kit. SCF is released from its membrane-bound form via MMP-9. This finding and the dramatic increase in c-kit expression observed in the rat carotid artery after balloon injury suggests SCF/c-kit signaling may affect SMC function via an autocrine pathway. (C) 2004 Elsevier Inc. All rights reserved.