力学刺激部位への血管内皮細胞内PKCαの局在

抄録

Intracellular Ca²⁺ wave regulates several signal-transduction pathways. The translocation of Protein kinase C α (PKCα) by pharmacological stimulation occurs with an increase of intercellular Ca²+ concentration. A mechanical stimulation by micropipette also causes a transient rise in intracellular Ca²⁺ concentration and Ca²⁺ wave. However, the relationship beween PKCα and Ca²⁺ wave by mechanical stimulation is not understood well yet. In this study, we observed the change of intracellular PKCα distribution and intracellular calcium concentration simultaneously in Bovine Aortic Endothelial Cells (BAECs) by a mechanical stimulus. And, we investigated the relationship between PKCα distribution change and inflow of Calcium ion through Stretch Activated (SA) Channels. Mechanical stimulation induced a rapid Ca²⁺ wave and PKCα translocation to the stimulated region. Fluorescence of PKCα reached peak in around 20 sec after stimulation. When Calcium biding domein of PKCα was inhibited and when the SA channel was inhibited, PKCα translocation was not observed. Moreover, when Ca²⁺ in the extracellular medium was chelated by EGTA, PKCα translocation was not observed. On the other hand, PKCα translocation was observed even though endoplasmic reticulum Ca²⁺ was inhibited. These results suggested that extracellular Ca²⁺ through SA Channels is necessary to PKCα translocation by mechanical stimulation.