Stawowy P, Marcinkiewicz J, Graf K, Seidah N, Chrétien M, Fleck E, Marcinkiewicz M
Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, Montreal, Quebec, Canada.
J Histochem Cytochem. 2001 Mar;49(3):323-32. doi: 10.1177/002215540104900306.
The aim of this study was to investigate whether transformation of quiescent vascular smooth muscle cells (VSMCs) into proliferating secretory cells is accompanied by an expression of processing enzymes that activate de novo-synthesized growth factors. Three enzymes belonging to the family of the kexin/subtilisin-like mammalian proprotein convertases (PCs), furin, PC5, and PC7, were found to be upregulated after balloon denudation in vivo. To determine their importance in these cell processes, we investigated their gene regulation using a short-term organ culture system. After incubation of rat aorta for 4 and 24 hr in serum-free medium, we demonstrated a significant induction of VSMC proliferation. The affected subset of VSMCs, positive for alpha-smooth muscle actin, also expressed proliferating cell nuclear antigen (PCNA). Our results revealed a parallel upregulation of furin, PC5, and PC7 in PCNA-immunolabeled cells. As a substrate model for comparison with PCs we used nerve growth factor (NGF). NGF is known to be activated by PCs. As shown by Northern blotting analysis, NGF mRNA concentration was significantly increased in cultured explants. NGF was released into the culture medium. In conclusion, both PCs and NGF are coordinately modulated on induction of VSMC proliferation.
本研究的目的是调查静止的血管平滑肌细胞（VSMC）向增殖性分泌细胞的转变是否伴随着激活新生合成生长因子的加工酶的表达。发现属于克新/枯草杆菌蛋白酶样哺乳动物前体蛋白转化酶（PC）家族的三种酶，即弗林蛋白酶、PC5和PC7，在体内球囊剥脱后上调。为了确定它们在这些细胞过程中的重要性，我们使用短期器官培养系统研究了它们的基因调控。在无血清培养基中培养大鼠主动脉4小时和24小时后，我们证明了VSMC增殖的显著诱导。受影响的VSMC亚群，α-平滑肌肌动蛋白呈阳性，也表达增殖细胞核抗原（PCNA）。我们的结果显示，在PCNA免疫标记的细胞中，弗林蛋白酶、PC5和PC7平行上调。作为与PCs比较的底物模型，我们使用了神经生长因子（NGF）。已知NGF被PCs激活。如Northern印迹分析所示，培养外植体中NGF mRNA浓度显著增加。NGF被释放到培养基中。总之，在VSMC增殖诱导过程中，PCs和NGF均受到协同调节。
