Role of gap-junctional communication in cell proliferation and adipocyte conversion

细胞间隙连接通讯被认为在细胞增殖和分化的调控中起重要作用，并对其调控的确切机制进行了研究。血清的生长刺激作用短暂抑制3 t3-L1细胞的缝隙连接通讯，然后促进DNA合成。用12-O-十四烷酰佛波醇-13-乙酸酯（TPA）预处理静止细胞，抑制间隙连接通讯，增强血清诱导的DNA合成。二丁酰环腺苷酸（cAMP）预处理刺激细胞通讯，抑制血清诱导的DNA合成。血清的添加诱导3 T3-L1细胞的脂肪细胞转化。TPA抑制脂肪细胞转化，cAMP促进脂肪细胞转化。通过分离细胞同源物来研究通过间隙连接交换的物质。钙离子是可透过缝隙连接的小分子物质的候选者。生长刺激也诱导细胞内钙离子浓度的增加。TPA处理也促进了钙离子的增加，cAMP抑制了钙离子的增加。在本项目中，缝隙连接通讯参与了细胞增殖和细胞分化的控制。

Gap junctional intercellular communication is considered to play an important role in the control of cell proliferation and cell differentiation, and the exact mechanism of its control was investigated. Growth Stimulation by the serum transiently suppressed the gap-junctional communication and then enhanced DNA synthesis in 3t3-L1 cells. Pretreatment of quiescent cells with 12-O-tetradecanoylphorbol-13-acetate (TPA) suppressed the gap-junctional communication and enhanced serum-induced DNA synthesis. Pretreatment with dibutyryl cyclic AMP (cAMP) stimulated the cell communication and suppressed serum-induced DNA synthesis. The addition of the serum induced adipocyte conversion from 3T3-L1 cells. TPA inhibited adipocyte conversion and cAMP enhanced adipocyte conversion. Substances exchanged through gap junctions were investigated by fractionating the cell homoginates. Calcium ions are candidates for small substances permeable through gap junction.s Growth stimulation also induced the increase in the intracellular concentration of calcium ions. Treatment with TPA also enhanced the increase in calcium ions and cAMP suppressed it. In this project, the gap-junctional communication is suggested to be involved in the control of cell proliferation and cell differentiation.