摘要
为探讨转录因子活化子蛋白１（ＡＰ－１）和相关的信号转导分子在凝血酶诱导人肾小球系膜细胞纤溶酶原激活物抑制物１（ＰＡＩ－１）表达中的作用，采用纤维蛋白平板法、Ｎｏｒｔｈｅｒｎ杂交、凝胶电泳阻滞实验（ＥＭＳＡ）和Ｗｅｓｔｅｒｎ杂交方法，分别检测凝血酶刺激培养的人肾小球系膜细胞ＰＡＩ－１蛋白质活性和ｍＲＮＡ表达情况，以及ＡＰ－１ＤＮＡ连接活性和ＡＰ－１组成蛋白质ｃ－Ｊｕｎ、ｃ－Ｆｏｓ量的变化。结果发现：①凝血酶呈浓度依赖性的方式促进肾小球系膜细胞ＰＡＩ－１蛋白质活性和ｍＲＮＡ表达，其效应能被凝血酶的特异性拮抗剂水蛭素阻断；②凝血酶能明显促进转录因子ＡＰ－１的ＤＮＡ连接活性；③ｃｕｒｃｕｍｉｎ、ｓｔａｕｒｏｓｐｏｒｉｎｅ和ｇｅｎｉｓｔｅｉｎ均能在不同程度上抑制ＡＰ－１的ＤＮＡ连接活性，并进而部分逆转凝血酶上调系膜细胞ＰＡＩ－１ｍＲＮＡ表达的效应。研究表明，转录因子ＡＰ－１在凝血酶上调人肾小球系膜细胞ＰＡＩ－１表达的信号转导过程中起着重要的作用，蛋白激酶Ｃ和蛋白酪氨酸激酶可能是凝血酶介导系膜细胞ＡＰ－１活化及ＰＡＩ－１表达的上游信号。
To explore the intracellular signaling
transduction pathways of the expression of plasminogen activator inhibitor type 1 (PAI1)
induced by thrombin in human glomerular mesangial cells, Fibrin plate method, Northern blot,
electrophoretic mobility shift assay and Western blot were used to examine the protein activity
and mRNA expression of PAI1, AP1 DNAbinding activity and protein quantity of cJun and cFos,
which are the major compositions of AP1 complex, in cultured human mesangial cells induced
by thrombin. Results: (1)Thrombin could enhance PAI1 protein activity and mRNA expression in
a dosedependent manner,and its upregulative effect was blocked by hirudin, a specific inhibitor
of thrombin. (2)Thrombin increased AP1 DNAbinding activity. However, staurosporine and
genistein, which are specific inhibitors of protein kinase C (PKC) and protein tyrosine kinase
(PTK) respectively, could partly block AP1 DNAbinding activity. (3)High PAI1 mRNA levels
induced by thrombin were partly reversed by pretreatment of mesangial cells with curcumin,
staurosporine and genistein. Conclusions: Transcription factor AP1 plays an important role in
intracellular signaling transduction in the excretion and expression of PAI1 induced by thrombin
in human glomerular mesangial cells. Moreover, PKC and PTK may be the upstream signaling
transducer of AP1 activation and PAI1 expression.
出处
《解放军医学杂志》
CAS
CSCD
北大核心
1999年第3期168-172,共5页
Medical Journal of Chinese People's Liberation Army
基金
国家自然科学基金
"九.五"军队医药卫生科研基金
关键词
信号转递
肾小球
系膜细胞
凝血酶
PAI-1
signal transduction
protooncogene proteins cJun
plasminogen activator inhibitor 1
thrombin
