简介:肌动蛋白调节蛋白,cofilin在许多细胞中起着关键的信号传导作用,用于许多细胞反应,包括增殖,发展,运动性,迁移,分泌和生长。在胰腺中,它对胰岛胰岛素分泌很重要,胰腺癌细胞的生长和胰腺炎。然而,目前尚无关于其在胰腺腺泡细胞中的作用或激活的研究。方法:为了解决这个问题,我们研究了CCK激活胰腺腺泡细胞中的cofilin的能力,AR42J细胞和CCK1-R转染的Panc-1细胞,所涉及的信号级联及其对酶分泌和MAPK激活的影响,胰腺生长的关键介质。结果:CCK(0.3和100nM),TPA,卡巴胆碱,Bombesin,促胰液素和VIP减少磷酸-cofilin(即,激活cofilin)以及cofilin的磷酸动力学和抑制剂研究,LIM激酶(LIMK)和弹弓蛋白磷酸酶(SSH1)表明,这些常规的cofilin激活剂均未涉及。丝氨酸磷酸酶抑制剂(calyculinA和冈田酸),然而抑制CCK/TPA-cofilin激活。各种CCK激活的信号级联的研究显示PKC/PKD的激活,Src,PAK4JNK,ROCK介导的cofilin激活,但不是PI3K,p38,或MEK。此外,使用siRNA和cofilin抑制剂,表明cofilin激活对于CCK介导的酶分泌和MAPK激活至关重要。结论:这些结果支持以下结论:在CCK介导的胰腺腺泡生长/酶分泌中,cofilin激活对各种细胞信号传导级联起着关键的会聚作用。
Introduction: The actin regulatory protein, cofilin plays a key signaling role in many cells for numerous cellular responses including in proliferation, development, motility, migration, secretion and growth. In the pancreas it is important in islet insulin secretion, growth of pancreatic cancer cells and in pancreatitis. However, there are no studies on its role or activation in pancreatic acinar cells. Methods: To address this question, we studied the ability of CCK to activate cofilin in pancreatic acinar cells, AR42J cells and CCK1-R transfected Panc-1 cells, the signaling cascades involved and its effect on enzyme secretion and MAPK activation, a key mediator of pancreatic growth. Results: CCK (0.3 and 100 nM), TPA, carbachol, Bombesin, secretin and VIP decreased phospho-cofilin (i.e., activate cofilin) and both phospho-kinetic and inhibitor studies of cofilin, LIM kinase (LIMK) and Slingshot Protein Phosphatase (SSH1) demonstrated these conventional activators of cofilin were not involved. Serine phosphatases inhibitors (calyculin A and okadaic acid), however inhibited CCK/TPA-cofilin activation. Studies of various CCK-activated signaling cascades showed activation of PKC/PKD, Src, PAK4, JNK, ROCK mediated cofilin activation, but not PI3K, p38, or MEK. Furthermore, using both siRNA and cofilin inhibitors, cofilin activation was shown to be essential for CCK-mediated enzyme secretion and MAPK activation. Conclusion: These results support the conclusion that cofilin activation plays a pivotal convergent role for various cell signaling cascades in CCK mediated growth/enzyme secretion in pancreatic acini.