丝裂素激活蛋白激酶活化与肾小管上皮细胞生物学行为的关系  

Influence of MAPK activation on PDGF induced transdifferentiation and migration in renal proximal tubular cells

作　　者：张梅[1] 李晓玫[1] 

机构地区：[1]北京大学第一医院北京大学肾脏病研究所,100034

出　　处：《中华肾脏病杂志》2004年第3期177-180,共4页Chinese Journal of Nephrology

基　　金：国家自然科学基金(30070351);教育部跨世纪优秀人才基金(39910210474-231-C04)

摘　　要：目的探讨丝裂素激活蛋白激酶(MAPK)信号通路对血小板源生长因子(PDGF)诱导肾小管上皮细胞表型转化的作用及其对细胞移行能力的影响。方法以PDGF(20ng/ml)刺激培养的人近端肾小管上皮HK-2细胞,分别观察细胞形态、增殖和移行能力的变化。采用蛋白免疫印记法检测MAPK各亚类活性及α-平滑肌肌动蛋白(SMA)的表达,同时观察分别采用细胞外信号调节激酶(ERK)、c-Jun氨基末端激酶(JNK)和p38信号通路特异阻断剂PD98059、SP600125和SB203580后上述指标的变化。结果PDGF刺激6～12h使α-SMA表达上调近2倍,但刺激24～48h反而使α-SMA表达低于基础水平。PDGF刺激24h后HK-2细胞从立方形转变为梭形,细胞虽尚无增殖反应但移行能力增强至3倍(P<0.01)。PDGF诱导的ERK、JNK和p38活性均在2min时迅速增高,分别在2～5min达高峰,分别为基础水平的5.7倍、2.6倍和1.6倍(P<0.05),ERK和JNK活性增高可持续至120min,而p38活性则于60min以后恢复至基础水平。在PDGF刺激24h的情况下,PD98059和SP600125不影响基础状态及PDGF对α-SMA表达的作用,但SP600125可抑制PDGF上调的细胞移行能力(P<0.01);而SB203580既可抑制α-SMA的基础表达(P<0.01)及PDGF下调的α-SMA表达(P<0.001),同时还可显著抑制PDGF诱导的细胞移行能力(P<0.05)。结论PDGF可刺?Objective To investigate the role of MAPK signaling pathways on PDGF induced transdifferentiation and migration in renal proximal tubular cells(HK 2).Methods After PDGF stimulation, expression and distribution of cytokeratin as the phenotypic markers of epithelium, α SMA as a marker of myofibroblast were detected by fluorescence microscope and confocal microscopy. Morphological change was monitored at the 24th hour.Expression of α SMA and phosphorylation of p38MAPK were assayed by Western blot using specific antibodies. The blockage of p38MAPK activation was detected by using specific inhibitor SB203580. Cell cell adhesion and migration assay were performed as functional studies.Results After treatment with PDGF (20 ng/ml), activity of p38MAPK was up to 1 4～1 6 folds from 2 to 5 min in HK 2 cells respectively. Activation of this kinase lasted 30 min,and then the expression of α SMA up regulated from 6 to 12 hours but declined from 24 to 48 hours. At 24 hour point,decreased expression of cytokeratin and disordered distribution of α SMA were found. Some HK 2 cells treated with PDGF became elongated in shape and lost their cobblestone monolayer pattern. Cell cell adhesion did not changed but migration ability was enhanced in HK 2 cells treated by PDGF. PDGF induced expression of α SMA and the enhancing of cell migration were suppressed by blocking p38MAPK. Conclusions PDGF induces transdifferentiation of renal proximal tubular cells characterized by α SMA expression and the enhanced ability of cell migration. These effects are mediated, at least in part, through the activation of p38 MAPK signaling pathway.

关 键 词：丝裂素 蛋白激酶 酶活化 肾小管上皮细胞 生物学行为 MAPK 血小板源生长因子 PDGF 

分 类 号：R692.3[医药卫生—泌尿科学]