丝裂原活化蛋白激酶对大鼠成骨细胞TRPV6表达的影响

目的探讨丝裂原活化蛋白激酶对大鼠成骨细胞瞬时性受体电位香草精受体6（transient receptor poten-tial vanilloid receptor 6,TRPV6）表达的影响。方法采用Wistar大鼠乳鼠,连续酶消化法提取成骨细胞并培养。根据组织形态学、改良Kaplow氏成骨细胞碱性磷酸酶染色、矿化结节茜素红染等方法进行鉴定。实验分组：a）正常对照组;b）PD组（PD98059 5μmol/L;PD98059 10μmol/L;PD98059 20μmol/L）;c）SB组（SB203580 5μmol/L;SB20358010μmol/L;SB203580 20μmol/L）;d）PD＋SB组（PD98059 5μmol/L＋SB203580 5μmol/L;PD98059 10μmol/L＋SB203580 10μmol/L;PD98059 20μmol/L＋SB203580 20μmol/L）。细胞计数法、MTT法检测细胞活性,RT-PCR检测成骨细胞TRPV6 mRNA。所得数据用x-±s表示,采用t检验进行统计学分析。结果随着PD98059和/或SB203580浓度的增加,细胞增殖活性有下降的趋势,二者联合作用时细胞活性低于二者单独作用。细胞计数法检测显示,PD98059与SB203580联合作用时,三种组合中细胞数均显著低于空白对照组,P〈0.01;同时也明显低于二者单独作用组细胞数量。碱性磷酸酶染色显示,联合用药组较单独用药细胞数明显减少,细胞体积变小,突起狭长,ALP染色阳性颗粒减少,随药物作用浓度增加上述变化更加显著。茜素红染色显示,钙结节与对照组比较数量少、体积小;10、20μmol/L联合作用组,细胞数减少更加明显,无钙结节形成。SB203580与PD98059二者联合应用显著抑制TR-PV6 mRNA的表达,5 mmol/L联合作用组即可明显抑制,随着作用浓度增加TRPV6 mRNA的表达量逐渐减少。结论 p44/42途径阻断剂PD98059能抑制成骨细胞增殖,明显降低成骨细胞TRPV6 mRNA表达,减少钙结节形成。p38途径阻断剂SB203580能抑制成骨细胞增殖,明显降低成骨细胞TRPV6 mRNA表达,减少钙结节形成。PD98059与SB203580在抑制成骨细胞增殖、降低成骨细胞TRPV6 mRNA表达、减少钙结节形成的作用方面存在协同作用。     

P38 MAPK抑制剂在高糖诱导系膜细胞CTGF表达和基质蛋白分泌中的作用

目的:探讨P38 MAPK抑制剂SB203580在高糖诱导大鼠肾小球系膜细胞对丝裂原活化蛋白激酶磷酸酶-1(mitogen-activated protein kinase phosphatase-1,MKP-1)与结缔组织生长因子(connective tissue growth factor,CTGF)表达和细胞外基质蛋白分泌的作用。方法:体外培养大鼠肾小球系膜细胞分为4组:正常对照组(NG组,5. 5 mmol/L葡萄糖);渗透压对照组(NG+M组,5. 5 mmol/L葡萄糖+24. 5 mmol/L甘露醇);高糖组(HG组,30 mmol/L葡萄糖);高糖+SB203580组(HG+SB203580组,30 mmol/L葡萄糖+10μmol/L SB203580),分别给予不同刺激。48 h收集细胞,分别提取系膜细胞蛋白、RNA及细胞上清液。采用Western blot检测MKP-1、p38 MAPK及磷酸化p38MaPK的表达; RT-PCR检测p38 MAPK、MKP-1、CTGF和FN mRNA的表达; ELISA法测定细胞上清CTGF和纤维黏连蛋白(fibronectin,FN)含量,放免法测定细胞上清液Ⅳ型胶原的含量。结果:与NG组相比,HG组系膜细胞MKP-1表达下调,p38 MAPK蛋白表达无明显差别,但磷酸化的p38 MAPK表达明显升高,MKP-1 mRNA表达下降,p38 MAPK、CTGF和FN mRNA的表达增加,细胞上清液中CTGF、FN和Ⅳ型胶原含量增加;与HG组相比,HG+SB203580组MKP-1表达升高,p38 MAPK蛋白表达无明显差别,但磷酸化的p38MAPK表达明显下降,p38 MAPK、CTGF和FN mRNA的表达下降,系膜细胞上清液中CTGF、FN和Ⅳ型胶原含量下降。结论:p38 MAPK抑制剂SB203580通过增强MKP-1的表达,增强p38 MAPK去磷酸化,使p38 MAPK活性下降,从而阻断CTGF的合成和细胞外基质蛋白表达,在糖尿病肾病细胞外基质重构中发挥保护作用。     

丝裂原活化蛋白激酶类和蛋白激酶C在转化生长因子β1诱导肾小管细胞结缔组织生长因子表达中的作用

目的了解转化生长因子β1（TGF-β1）诱导肾小管细胞结缔组织生长因子（CTGF）表达的机制，特别是蛋白激酶C（PKC）和丝裂原活化蛋白激酶（MAPK）在CTGF基因表达中的作用及其对Smad磷酸化的影响。方法分别应用PKC抑制剂G06850以及MAPK的3个组成成分ERK、JNK和p38MAPK的抑制剂PD98059、U0126、SP600125和SB203580阻断相应通路，观察其对TGF．131诱导的CTGF表达以及Smad2／Smad3磷酸化的影响。结果TGF-β1（5μg／L）以时间依赖方式诱导HK-2细胞中Smad2／Smad3的磷酸化，从基础值0．87±0．09上升至2h时高峰2．350±0.11。PKC抑制剂G06850（5μmol／L）和ERK抑制剂PD98059（10μmol／L）、U0126（10μmol／L）可部分抑制TGF-β1诱导的CTGF表达，而p38MAPK抑制剂SB203580（20μmol／L）和JNK抑制剂SP600125（10μmol／L）对TGF-β1诱导的CTGF的表达无影响。PKC抑制剂G06850（5μmol／L）可减少TGF-β1诱导的Smad2／Smad3磷酸化，而ERK抑制剂PD98059（10μmol／L）和U0126（10μmol／L）对Smad2／Smad3的磷酸化没有影响。结论在肾小管上皮细胞中，TGF-β1诱导CTGF的表达需要PKC和Ras／MEK／ERK的参与。PKC以Smad依赖的方式参与肾小管上皮细胞中TGF-β1诱导的CTGF的表达，而Ras／MEK／ERK对CTGF表达的调节不依赖于Smads。     

p38MAPK与 ERK1/2的协同效应及对成骨细胞分化的调控

 目的探讨骨髓间质干细胞(bone marrow mesenchymal stem cells,BMSCs)向成骨细胞分化过程中 p38MAPK与 ERK1/2的协同效应及其机制。方法以成骨细胞分化添加剂诱导小鼠 BMSCs向成骨细胞分化,测定碱性磷酸酶活性和钙沉积量。检测磷酸化 p38MAPK和磷酸化 ERK1/2(p-ERK1/2)的表达水平评估通路的激活状况。以 SB203580或 PD98059阻断 p38MAPK或 ERK1/2通路,观察对成骨细胞分化的影响。以 SB203580或亚砷酸钠阻断或激活 p38MAPK通路,观察 p-ERK1/2的变化。以冈田酸抑制蛋白磷酸酯酶 2A(protein phosphatases type 2A,PP2A)活性,观察 p-ERK1/2的变化及对成骨细胞分化的影响。通过免疫共沉淀实验观察 PP2A和 ERK1/2间的结合及 SB203580对结合的影响。结果成骨细胞分化添加剂诱导 BMSCs向成骨细胞分化的过程伴有 ERK1/2和 p38MAPK通路的激活, SB203580剂量±赖性抑制成骨细胞分化,PD98059剂量±赖性增强成骨细胞分化。 SB203580使 p-ERK1/2表达增加,亚砷酸钠减弱其表达。冈田酸使 p-ERK1/2表达增加,并使成骨细胞分化受到抑制。 PP2A可直接与 ERK1/2结合,SB203580使 PP2A与 ERK1/2的结合减弱。结论 p38MAPK可通过 PP2A与 ERK1/2产生协同效应,并调节 BMSCs向成骨细胞分化。     

氟伐他汀对血管紧张素Ⅱ诱导的大鼠肾小管上皮细胞核因子κB活性的影响

目的 观察氟伐他汀对血管紧张素（Ang）Ⅱ诱导的大鼠肾小管上皮细胞（NRK-52E）内核因子（NF）κB活性的影响。 方法 将NRK-52E细胞分为（1）对照组;（2）不同浓度及时间AngⅡ组;（3）AngⅡ（10-6 mol/L）+SB203580（10 μmol/L）组;（4）AngⅡ（10-6 mol/L）+不同浓度氟伐他汀（10-7、10-6、10-5 mol/L）组;(5)AngⅡ（10-6 mol/L）+氟伐他汀（10-5 mol/L）+甲羟戊酸（10-4 mol/L）组。电泳迁移率变动分析法（EMSA）检测NF-κB活性变化。Western印迹方法检测p38丝裂原活化蛋白激酶(p38MAPK)磷酸化水平。RT-PCR方法检测单核细胞趋化因子（MCP-1）mRNA表达。 结果 AngⅡ呈剂量依赖性上调NF-κB DNA结合活性、p38MAPK的磷酸化水平以及MCP-1 mRNA表达（P < 0.01）。AngⅡ(10-6 mol/L) 刺激5 min即可增加p38MAPK蛋白磷酸化水平（P < 0.01）。AngⅡ刺激30 min后NF-κB活性显著升高（P < 0.01）,2 h达高峰（P < 0.01）。p38MAPK 特异性抑制剂SB203580可阻断AngⅡ对NF-κB的激活作用（P < 0.01）。氟伐他汀可呈剂量依赖性下调AngⅡ诱导的NRK-52E细胞内p38MAPK磷酸化和NF-κB活化,以及其下游趋化因子MCP-1表达（P < 0.05）。甲羟戊酸（10-4 mol/L）可逆转氟伐他汀的作用（P < 0.05）。 结论 氟伐他汀可能通过抑制p38MAPK信号转导通路,下调AngⅡ诱导的NRK-52E细胞内NF-κB的活化。甲羟戊酸可部分逆转氟伐他汀的作用。     

白细胞介素1β通过p38信号通路上调大鼠肾小球系膜细胞骨调素mRNA的表达

目的 探讨p38信号通路(1938MAPK)在白细胞介素1(IL-1)β介导的大鼠肾小球系膜细胞表达骨调素(OPN)中的作用。方法 应用Western印迹检测p38MAPK在IL-1β诱导的肾小球系膜细胞炎症反应中的活化程度。应用逆转录-聚合酶链式反应(RT-PCR)法观察p38MAPK特异性阻断剂SB203580对IL-1β诱导的系膜细胞促炎症介质OPNmRNA的影响。结果 IL-1β以时间和剂量依赖方式刺激系膜细胞引起p38MAPK的活化，并明显上调系膜细胞OPNmRNA的表达。p38MAPK特异性抑制剂SB203580以剂量依赖性方式显著抑制IL-1β诱导的OPNmRNA的表达。结论 p38MAPK在IL-16介导的肾小球系膜细胞上调表达黏附分子OPN中起重要作用。     

PD98059对酸性成纤维细胞生长因子诱导的EJ细胞增殖的抑制作用

目的观察细胞外调节蛋白激酶(ERK)激酶MEK1抑制剂PD98059对酸性成纤维细胞生长因子(aFGF)诱导的人膀胱癌细胞株EJ细胞增殖的抑制作用;探讨aFGF诱导EJ细胞增殖的细胞内信号传导途径。方法用不同浓度的aFGF刺激EJ细胞并测定ERK活性;对aFGF诱导增殖的EJ细胞施以不同浓度的PD98059,噻唑蓝(MTT)法检测细胞增殖。结果随aFGF浓度增加,EJ细胞内ERK活性升高,当aFGF浓度为0.6 mg/L,ERK活性是对照组的223.62%; PD98059可使aFGF诱导的EJ细胞增殖比下降,当PD98059浓度为0.1μmol/L,增殖比为46.64%。结论ERK通路是aFGF诱导EJ细胞增殖的重要细胞内信号传导通路,PD98059可抑制aFGF诱导的EJ细胞增殖。     

p38丝裂原活化蛋白激酶在罗哌卡因致SH-SY5Y细胞凋亡中的作用

目的 评价p38丝裂原活化蛋白激酶(p38MAPK)在罗哌卡因致SH-SY5Y细胞凋亡中的作用,以探讨罗哌卡因诱发神经毒性的机制.方法 采用随机数字表法,将SH-SY5Y细胞随机分为4组(n=18):正常对照组(C组)、10 μmol/L p38MAPK特异性抑制剂SB203580组(SB组)、3 mmol/L罗哌卡因组(R组)、10 μmol/L SB203580+3 mmol/L罗哌卡因组(SB+R组).C组在细胞培养液中继续培养；SB组在含10 μmol/L SB203580培养液中孵育；R组在含3 mmol/L罗哌卡因的培养液中孵育；SB+R组在含10 μmol/L SB203580的培养液中孵育30 min后,用含3mmol/L罗哌卡因的培养液继续孵育.各组细胞培养或罗哌卡因孵育4 h后采用流式细胞仪检测细胞内活性氧(ROS)水平和细胞凋亡率,采用Western blot法检测p38MAPK和磷酸化p38MAPK(p-p38MAPK)的表达,采用MTT法检测细胞活力.结果 与C组比较,R组和SB+R组ROS水平升高,p-p38MAPK表达上调,细胞活力降低,细胞凋亡率升高(P＜0.01),SB组上述指标差异无统计学意义(P＞0.05)；与R组比较,SB组p-p38MAPK表达下调,细胞活力升高,细胞凋亡率降低(P＜0.01).四组p38MAPK表达水平差异无统计学意义(P＞0.05).结论 罗哌卡因致SH-SY5Y细胞凋亡作用的机制部分与p38MAPK的激活有关.     

斯伐他汀对糖尿病肾病大鼠肾小球系膜细胞p38信号通路的影响

目的研究糖尿病肾病大鼠肾小球系膜细胞p38丝裂原活化蛋白激酶（MAPK）的表达及斯伐他汀对其的影响。方法分别以高糖、糖基化终产物（AGE）及过氧化氢孵育糖尿病大鼠肾小球系膜细胞（RMC），Western印迹法检测RMC的p38MAPK和TGF—β蛋白表达，p38MAPK特异性抑制剂SB203580及斯伐他汀预处理对其影响。结果高糖、AGE及过氧化氢均可单独激活p38MAPK，增加RMC的磷酸化（P）p38MAPK和TGF—β的蛋白表达；SB203580显著抑制TGF—β的蛋白表达（P〈0．05）；斯伐他汀抑制p38MAPK的活化并减少TGF—β的蛋白表达（P〈0．05）。结论p38MAPK可能是糖尿病肾病发生的始动信号之一。斯伐他汀可能通过抑制p38MAPK磷酸化而减少TGF—β的蛋白表达。     

转化生长因子β1对肾小管上皮细胞中结缔组织生长因子基因启动子活性的影响

目的探讨转化生长因子[β1（TCF-β1）对人近端肾小管上皮细胞系HK-2中结缔组织生长因子（CTGF）基因启动子活性的调控作用，以及丝裂原激活蛋白激酶（MAPK）途径对该生长因子作用的影响。方法构建含有人类CTGF基因启动子的报告基因pCTGF-luc，将其瞬时转染HK-2细胞。通过检测荧光素酶的活性观察TGF-β1和MAPK途径抑制剂对CTGF基因启动子活性的影响。结果TGF-β1以剂量和时间依赖方式上调HK-2中CTGF基因启动子的活性。最佳刺激浓度是5ng／ml，最佳刺激时间为12h，荧光素酶相对活性分别为对照组的1．82倍和2．10倍（P〈0．05）。应用PD98059、SB203580和SP600125分别特异性抑制MAPK途径的胞外信号调节蛋白激酶（ERK）、蛋白激酶p38（p38MAPK）和c-Jun-氨基末端激酶（JNK）通路，对TGF-β1上调CTGF启动子活性的作用有不同影响。PD98059显著增加HK-2中pCTGF-luc的基础活性．并在一定浓度范围内（0．5～10μmol／L）促进TGF-β1的上调作用。SB203580对pCTGF-luc基础活性无影响，但以剂量依赖方式显著抑制TGF-β1的激活效应。而SP600125对基础状态和TGF-β1刺激下CTGF基因启动子活性无影响。结论TGF-β1以剂量和时间依赖方式上调HK-2中CTGF基因启动子活性，在转录水平调节CTGF表达。MAPK途径的ERK和p38MAPK通路可影响TGF-β1的这一调控作用。     

Modulation of renal epithelial barrier function by mitogen-activated protein kinases (MAPKs): mechanism of cyclosporine A-induced increase in transepithelial resistance

BACKGROUND: Cyclosporine A (CsA) has been shown to increase transepithelial resistance in Madin-Darby canine kidney (MDCK) cells, and the mechanism may involve altered phosphorylation of junctional proteins. In this study, we examine the effect of the extracellular signal-regulated protein kinase (ERK) 1/2 and p38 mitogen-activated protein kinase (MAPK) pathways on the basal transepithelial resistance (TER) and on the CsA-induced increase in TER across MDCK monolayers. Here we present evidence that CsA may be mediating some of its effects through activation of the ERK 1/2 MAPK pathway. METHODS: MDCK cells were treated with CsA (4.2 micromol/L) and paracellular permeability was assessed by measuring TER. The role of the ERK 1/2 and the p38 MAPK pathways in modulating TER was investigated using the inhibitors PD98059 and U0126 for ERK 1/2 and SB203580 for p38. ERK 1/2 and p38 phosphorylation/activation was also examined by Western blot analysis. RESULTS: CsA (4.2 micromol/L) increased the TER of MDCK monolayers. The ERK 1/2 inhibitor PD98059 decreased basal TER and also ameliorated the CsA-induced increase in TER. Similar results were found with the U0126 inhibitor of ERK 1/2. The p38 inhibitor SB203580 had no effect on the basal TER of the monolayers, however, SB203580 significantly augmented the CsA-induced increase in TER. CsA was shown to significantly activate ERK 1/2 and this activation by CsA was prevented by PD98059. Inhibition of the p38 pathway by SB203580 also resulted in activation of ERK 1/2 and this activation of ERK 1/2 was further enhanced by CsA. No effect of CsA or the inhibitors PD98059 or SB203580 on p38 phosphorylation was detected. CONCLUSION: The results presented here suggest that activation of the ERK 1/2 MAPK cascade is important in the regulation of the paracellular permeability in MDCK cells. Activation of this pathway appears to be pivotal to the CsA-induced increase in TER.     

Role of MAP kinase pathways in mediating IL-6 production in human primary mesangial and proximal tubular cells.

BACKGROUND: Both interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) are pleiotropic cytokines that have been implicated in the development of glomerular and tubular injury in various forms of immune-mediated renal disease, including glomerulonephritis. Although TNF-alpha has been shown to stimulate IL-6 production in renal cells in culture, the signaling mechanisms that regulate IL-6 production are not fully understood. The aim of this study was to examine the role of the p38 and extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase (MAPK) pathways in regulating TNF-alpha-mediated IL-6 production from both primary human mesangial cells (HMCs) and human proximal tubular (HPT) cells. METHODS: Primary mesangial and proximal tubular cells were prepared from nephrectomized human kidney tissue. Cells were treated for 24 hours with TNF-alpha in the presence and absence of the specific p38 and ERK1,2 MAPK inhibitors SB203580 and PD98059, respectively, either alone or in combination. IL-6 levels in the cell culture media were measured by enzyme-linked immunosorbent assay. MAPK activation was demonstrated by immunoblot for the active kinase (tyrosine/threonine phosphorylated) in whole cell extracts using phospho-specific antibodies. p38 MAPK activity in HPT cells was measured using an in vitro immunokinase assay using ATF2 as the substrate. RESULTS: TNF-alpha (0.1 to 100 ng/ml) stimulated a dose-dependent increase in IL-6 production in both renal cell types. The activation of the p38 and the ERK1,2 MAPKs occurred following TNF-alpha stimulation. The role of these activations in IL-6 production was confirmed by the ability of both inhibitors SB203580 (1 to 30 microM) and PD98059 (0.01 to 10 microM) to inhibit basal and TNF-alpha-stimulated IL-6 production in both cell types. The addition of both inhibitors in combination caused greater decreases in IL-6 production compared with either inhibitor alone. Pretreatment with SB203580 (10 microM) had no effect on basal or TNF-alpha-stimulated phosphorylation of p38 MAPK but completely abolished TNF-alpha-stimulated p38 MAPK activity. PD98059 decreased both basal and TNF-alpha-stimulated phosphorylation of ERK1,2. CONCLUSIONS: This study provides evidence that both the p38 and ERK MAPK pathways are important for the regulation of the production of IL-6 from the proximal tubular and glomerular mesangial regions of the nephron. In response to TNF-alpha, the activation of both pathways leads to IL-6 production. These findings could aid in an understanding of the cellular mechanisms that regulate IL-6 production and could provide insights into possible pharmacological strategies in inflammatory renal disease.     

Differential Activation of Mitogen-activated Protein Kinases in Ischemic and Anesthetic Preconditioning

Background: Accumulating evidence pinpoints to the pivotal role of mitogen-activated protein kinases (MAPKs) in the signal transduction underlying cardiac preconditioning.

Methods: PD98059, an inhibitor of extracellular signal-regulated protein kinase (MEK-ERK1/2), and SB203580, an inhibitor of p38 MAPK, were used to evaluate the role of MAPKs with respect to postischemic functional recovery in isolated perfused rat hearts subjected to ischemic preconditioning (IPC) and anesthetic preconditioning (APC). Western blot analyses were used to determine the degree of ERK1/2 and p38 MAPK activation after the application of the preconditioning stimulus and after ischemia-reperfusion. Immunohistochemical staining served to visualize subcellular localization of activated MAPKs.

Results: PD98059 and SB203580 abolished postischemic functional recovery in IPC but not in APC. IPC but not APC markedly activated ERK1/2 and p38 MAPK, which were abrogated by coadministration of the specific blockers. Conversely, IPC and APC enhanced ERK1/2 activity after ischemia-reperfusion as compared to nonpreconditioned hearts, and IPC in addition enhanced p38 MAPK activity. Coadministration of PD98059 and SB203580 during IPC but not during APC inhibited postischemically enhanced MAPK activities. Moreover, chelerythrine and 5-hydroxydecanoate, effective blockers of IPC and APC, annihilated IPC- and APC-induced enhanced postischemic responses of MAPKs. Finally, administration of PD98059 during ischemia-reperfusion diminished the protective effects of IPC and APC. Immunohistochemistry revealed increased ERK1/2 activity primarily in intercalated discs and nuclei and increased p38 MAPK activity in the sarcolemma and nuclei of IPC-treated hearts.     

缺氧时丝裂原激活蛋白激酶类对人肾小管上皮细胞富含半胱氨酸蛋白61基因转录活性的调控

目的 探讨丝裂原激活蛋白激酶类（MAPKs）对缺氧条件下人近端肾小管上皮细胞（HKC）中富含半胱氨酸蛋白61（Cyr61）基因转录活性的调控机制。方法 缺氧培养HKC，Northern印迹检测Cyr61mRNA表达；Western印迹检测Cyr61、p38、细胞外信号调节激酶（ERK1／2）、c—Jun—N末端蛋白激酶（JNK）以及缺氧诱导因子1c（HIF-1α）的表达。构建含有人Cyr61基因启动子的报告基因Cyr61-luc质粒，将其单独或者分别与表达活性MAPKs的质粒Ca—MEK1和Ca—MKK6共同瞬时转染HKC。通过荧光素酶活性检测观察缺氧、MAPKs抑制剂和MAPKs活性酶对Cyr61基因转录活性的调控。结果 缺氧时HKC表达cyr61、HIF-1α增高，ERK1／2、JNK、p38总量不变，而其各自的磷酸化形式均明显增加。HKC转染Cyr—luc后，p38通路抑制剂SB203580和ERK通路抑制剂PD98059显著抑制缺氧时Cyr61的转录活性，两者协同作用时抑制作用显著增强。Ca—MEK1与Cyr—luc共转染HKC后，Cyr61转录活性无改变；而Ca—MKK6与Cyr—luc共转染后，Cyr61转录活性显著增高。对缺氧培养的HKC，PD98059处理使HIF-1α和Cyr61蛋白表达显著降低；SB203580处理可显著降低Cyr61蛋白表达，但对HIF-1α无影响。结论 在HKC中，缺氧可通过p38通路直接上调Cyr61基因启动子活性，也可通过ERK1／2途径促进HIF-1α表达，间接调节Cyr61基因启动子活性。