摘要
佛波酯(TPA)是潜在促肿瘤剂,也是蛋白激酶PKC激活剂.TPA能在极低浓度下替代DG激活PKC,从而导致一系列细胞功能变化.应用100nmol/LTPA作用于NIH3T3细胞,观察NIH3T3细胞的粘附变化,发现TPA可促进NIH3T3细胞与基质纤连蛋白的粘附,进一步研究Fn的主要受体α5β1整合蛋白在细胞表面含量,发现TPA作用24h使α5及β1含量分别增加523%和516%.应用3H甘露糖标记N糖链和凝集素柱层析方法分析TPA作用后细胞N糖链总量和组分比,结果均与对照组相仿,说明是通过增加细胞合成整合蛋白α5及β1亚基含量实现的.在TPA作用于细胞的同时,加入PKC抑制剂Sphingosine,发现α5、β1含量和细胞与Fn的粘附均回复至对照组水平,提示TPA增加α5β1整合蛋白合成而增加的细胞与Fn粘附作用,是由PKC介导完成的.此外还发现酪氨酸蛋白激酶抑制剂也阻断TPA增加α5β1整合蛋白含量的作用.
TPA is a potential tumor promotor and an activator of protein kinase C(PKC). TPA can activate PKC as a substituter of DG in a very low concentration , thus causing a serial of changes of cells function. Observing the change in adhesion of NIH3T3 cell after using 100 nmol/L TPA to act on NIH3T3 cell, it was discovered that TPA increase NIH3T3 cell adhesion to Fn by increasing synthesis of integrin α 5、β 1 subunits. Further study on the content of integrin α 5、β 1 subunits——the major receptor of Fn on the cells surface showed that after the TPA acts on cell for 24 hours, the content of integrin α 5、β 1 subunits increased 52 3% and 51 6% respectively . To analyze the total content of N oligosaccharides and its constituent propertion after TPA acts on cell, 3H mannose incorporation into N oligosaccharides and lectins chromatography were used. The result has no difference from that of control . It can be said that increasing adhesion is induced increasing the syntheses the content of α 5 and β 1 subunits of the cells. The PKC inhibitor Sphingosine was added during TPA acting on cell, it was found that both the α 5 and β 1 content and the adhesion of cells to Fn recovered to the control level. It proved that increasing α 5β 1 synthesis thus increasing adhesion of cell to Fn by TPA is mediated by PKC. Besides the inhibitor of tyrosine protein kinase also can block the action of TPA increasing the content of α 5β 1 integrin syntheses.
出处
《生物化学与生物物理进展》
SCIE
CAS
CSCD
北大核心
2000年第1期61-65,共5页
Progress In Biochemistry and Biophysics
基金
国家自然科学基金!(39570 1 69)
上海市教委重点学科资助项目
