Virdee K, Brown B L, Dobson P R
Department of Human Metabolism and Clinical Biochemistry, University of Sheffield Medical School, UK.
Biochim Biophys Acta. 1994 Dec 30;1224(3):489-94. doi: 10.1016/0167-4889(94)90286-0.
In this study we have investigated the requirement for phosphoinositide metabolism, diradylglycerol (DG) production and protein kinase C (PKC) activation in recombinant basic fibroblast growth factor (rbFGF)-mediated reinitiation of DNA synthesis in Swiss 3T3 cells. We have assessed the involvement of PKC activation in rbFGF-induced DNA synthesis by two approaches; enzymic inhibition by H7 and down-regulation by prolonged phorbol-ester treatment. In both conditions we observed that rbFGF was able to sustain a significant component of its mitogenic response, therefore denying an exclusive role for the activation of downregulatable and H7-sensitive PKC isoforms in rbFGF-induced reinitiation of DNA synthesis. Moreover, we have found no evidence for diacylglycerol accumulation in response to rbFGF by 3T3 cells. In previous studies, we observed that rbFGF caused a moderate and slow accumulation of total inositol phosphates. This effect was significant only after a 60 min incubation. It is our contention that rbFGF, in our culture system, does not exert a direct effect on phosphoinositide metabolism.
在本研究中，我们调查了瑞士3T3细胞中磷酸肌醇代谢、二酰基甘油（DG）生成以及蛋白激酶C（PKC）激活在重组碱性成纤维细胞生长因子（rbFGF）介导的DNA合成重新启动中的需求。我们通过两种方法评估了PKC激活在rbFGF诱导的DNA合成中的作用；用H7进行酶抑制以及通过延长佛波酯处理进行下调。在这两种情况下，我们都观察到rbFGF能够维持其有丝分裂反应的一个重要组成部分，因此否认了可下调的和对H7敏感的PKC亚型的激活在rbFGF诱导的DNA合成重新启动中具有唯一作用。此外，我们没有发现3T3细胞对rbFGF产生二酰基甘油积累的证据。在先前的研究中，我们观察到rbFGF导致总肌醇磷酸适度且缓慢积累。这种效应仅在孵育60分钟后才显著。我们认为，在我们的培养系统中，rbFGF对磷酸肌醇代谢没有直接作用。
