Mata-Greenwood Eugenia, Liao Wu-Xiang, Zheng Jing, Chen Dong-Bao
Division of Maternal-Fetal Medicine (MC0802), Department of Reproductive Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0802, USA.
Placenta. 2008 Aug;29(8):708-17. doi: 10.1016/j.placenta.2008.05.005. Epub 2008 Jun 20.
Fibroblast growth factor (FGF2), but not vascular endothelial growth factor (VEGF), upregulates endothelial nitric oxide synthase (eNOS) protein expression, at least partially, via activation of extracellular signal-regulated kinase 2/1 (ERK2/1) in ovine fetoplacental artery endothelial (oFPAE) cells. Herein we further investigated the temporal effects of FGF2 and VEGF on other signalling pathways including members (Jun N-terminal kinase JNK1/2 and p38MAPK) of mitogen-activated protein kinases (MAPK), phosphatidylinositol-3 kinase/v-akt murine thymoma viral oncogene homologue 1 (PI3K/AKT1), and the tyrosine kinase c-SRC, and examined if either one or more of these pathways play a role in the differential regulation of eNOS by FGF2 and VEGF. We first confirmed that in oFPAE cells, FGF2, but not VEGF, increased eNOS protein. FGF2 stimulated eNOS protein in a time- and concentration-dependent manner, which also depended on cell density. FGF2 provoked sustained (5min to 12h) whereas VEGF only stimulated transient (5min) ERK2/1 phosphorylation. FGF2 was 1.7-fold more potent in stimulating ERK2/1 phosphorylation than VEGF. FGF2 and VEGF only transiently activated JNK1/2 and AKT1 within 5min; however, FGF2 was a stronger stimulus than VEGF. FGF2 and VEGF did not significantly activate p38MAPK at 5min; however, VEGF stimulated p38MAPK phosphorylation at 60min. VEGF but not FGF2 significantly stimulated c-SRC phosphorylation. Inhibitors of MEK-ERK2/1 (PD98059), JNK1/2 (SP600125) and PI3K (wortmannin), but not p38MAPK (SB203580) and SRC (PP2), decreased the FGF2-increased eNOS protein expression. Thus, the FGF2-induced eNOS protein expression requires activation of multiple signalling pathways including ERK2/1, JNK1/2 and PI3K/AKT1. Differences in intensity and temporal patterns of activation of these pathways by FGF2 and VEGF may account for their differential effects on eNOS expression in OFPAE cells.
成纤维细胞生长因子(FGF2)而非血管内皮生长因子(VEGF),至少部分地通过激活绵羊胎儿胎盘动脉内皮(oFPAE)细胞中的细胞外信号调节激酶2/1(ERK2/1)来上调内皮型一氧化氮合酶(eNOS)蛋白表达。在此,我们进一步研究了FGF2和VEGF对其他信号通路的时间效应,这些信号通路包括丝裂原活化蛋白激酶(MAPK)的成员(Jun氨基末端激酶JNK1/2和p38MAPK)、磷脂酰肌醇-3激酶/v-akt小鼠胸腺瘤病毒癌基因同源物1(PI3K/AKT1)以及酪氨酸激酶c-SRC,并研究了这些通路中的一个或多个是否在FGF2和VEGF对eNOS的差异调节中发挥作用。我们首先证实,在oFPAE细胞中,FGF2而非VEGF增加了eNOS蛋白。FGF2以时间和浓度依赖性方式刺激eNOS蛋白,这也取决于细胞密度。FGF2引起持续(5分钟至12小时)的ERK2/1磷酸化,而VEGF仅刺激短暂(5分钟)的ERK2/1磷酸化。FGF2刺激ERK2/1磷酸化的效力比VEGF高1.7倍。FGF2和VEGF仅在5分钟内短暂激活JNK1/2和AKT1;然而,FGF2比VEGF的刺激更强。FGF2和VEGF在5分钟时未显著激活p38MAPK;然而,VEGF在60分钟时刺激p38MAPK磷酸化。VEGF而非FGF2显著刺激c-SRC磷酸化。MEK-ERK2/1(PD98059)、JNK1/2(SP600125)和PI3K(渥曼青霉素)的抑制剂,但不是p38MAPK(SB203580)和SRC(PP2)的抑制剂,降低了FGF2诱导的eNOS蛋白表达。因此,FGF2诱导的eNOS蛋白表达需要激活包括ERK2/1、JNK1/2和PI3K/AKT1在内的多种信号通路。FGF2和VEGF对这些通路激活的强度和时间模式的差异可能解释了它们对oFPAE细胞中eNOS表达的不同影响。