Phosphatidylinositide 3-kinase γ regulates key pathologic responses to cholecystokinin in pancreatic acinar cells
Phosphatidylinositide 3-kinase γ regulates key pathologic responses to cholecystokinin in pancreatic acinar cells
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DOI：
10.1053/j.gastro.2003.11.017
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发表时间：
2004-02-01
期刊：
影响因子：
29.4
通讯作者：
Gukovskaya, AS
中科院分区：
文献类型：
--
作者：
Gukovsky, I;Cheng, JH;Gukovskaya, AS
背景和目标：胰腺腺泡细胞中对胰腺炎发展至关重要的早期事件包括转录因子核因子κ B（NF-κ B）的激活、异常Ca 2+反应和胰蛋白酶原激活。这些反应的机制，可以研究在离体胰腺腺泡刺激超生理剂量的胆囊收缩素（CCK-8），仍然知之甚少。我们在这里报告，这些反应是由磷脂酰肌醇3-激酶（PI 3 K）γ。研究方法：为了抑制PI 3 K，我们使用了缺乏催化性PI 3 K γ亚基p110 γ以及PI 3 K抑制剂LY 294002和渥曼青霉素的小鼠。我们使用Fura-2测量Ca 2+响应，通过电迁移率变动分析测量NF-κ B结合活性，通过Western印迹法测量IkappaB降解，通过荧光分析测量胰蛋白酶原激活。结果如下：CCK诱导的细胞内Ca 2+动员、Ca 2+内流、胰蛋白酶原和NF-κ B活化在从p110 γ（-/-）小鼠分离的胰腺腺泡中均减少。在小鼠和大鼠腺泡中，这些反应均被PI 3 K抑制剂抑制。与野生型小鼠相比，从p110 gamma（-/-）和p110 gamma（+/-）小鼠中分离的腺泡中的Ca 2+信号和胰蛋白酶原活化同样减少。相比之下，NF-κ B活化在p110 γ（-/-）腺泡中受到抑制，但在p110 γ（+/-）腺泡中没有。这些差异表明，NF-κ B调节PI 3 K γ的机制不同于那些钙离子和胰蛋白酶原的反应。CCK诱导的p110 γ（-/-）腺泡反应均被LY 294002进一步抑制，表明除PI 3 Ky外，还涉及其他PI 3 K亚型。结论：结果表明，胰腺腺泡细胞的关键病理反应由PI 3 K γ调节，并表明这种PI 3 K亚型在胰腺炎中的重要作用。
Background & Aims: Early events in the pancreatic acinar cell critical for development of pancreatitis include activation of the transcription factor nuclear factor kappaB (NF-kappaB), abnormal Ca2+ responses, and trypsinogen activation. Mechanisms underlying these responses, which can be studied in isolated pancreatic acini stimulated with supraphysiologic doses of cholecystokinin (CCK-8), remain poorly understood. We here report that these responses are regulated by phosphatidylinositide 3-kinase (PI3K) gamma. Methods: To inactivate PI3K, we used mice deficient in the catalytic PI3Kgamma subunit p110gamma as well as the PI3K inhibitors LY294002 and wortmannin. We measured Ca2+ responses by using Fura-2, NF-kappaB-binding activity by electromobility shift assay, IkappaB degradation by Western blotting, and trypsinogen activation by fluorogenic assay. Results: CCK-induced intracellular Ca2+ mobilization, Ca2+ influx, trypsinogen, and NF-kappaB activation were all diminished in pancreatic acini isolated from p110gamma(-/-) mice. Both in mouse and rat acini, these responses were inhibited by the PI3K inhibitors. The Ca2+ signal and trypsinogen activation were similarly reduced in acini isolated from p110gamma(-/-) and p110gamma(+/-) mice compared with wild-type mice. By contrast, NF-kappaB activation was inhibited in p110gamma(-/-) acini but not in p110gamma(+/-) acini. These differences indicate that the mechanism of NF-kappaB regulation by PI3Kgamma differs from those for the Ca2+ and trypsinogen responses. CCK-induced responses in p110gamma(-/-) acini were all further inhibited by LY294002, indicating the involvement of other PI3K isoform(s), in addition to PI3Ky. Conclusions: The results show that key pathologic responses of the pancreatic acinar cell are regulated by PI3Kgamma and suggest an important role for this PI3K isoform in pancreatitis.