Cellular signal transduction system in prostaglandin-stimulated osteoblast-like MC3T3-E1 cells : Phospholipid turnover and protein tyrosine phosphorylation

前列腺素刺激的成骨细胞样 MC3T3-E1 细胞中的细胞信号转导系统：磷脂周转和蛋白质酪氨酸磷酸化

基本信息

批准号：
06672000
负责人：
NAKASHIMA Shigeru
金额：
$ 1.41万
依托单位：
Gifu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

项目摘要

The combination of beta-glycerophosphate and ascorbic acid increased alkaline phosphate (ALP) activity, a maraker for osteoblastic differentiation, in clonal osteoblast like cell line MC3T3-E1. The increase was detected as 24 hours after the addition of these agents to growth medium and reached almost maximal level at 5 days of culture. Although increase in intracellular cyclic AMP level is known to induce osteoblastic acell differentiation, these treatment did not cause significant increase in cyclic AMP.Treatment of beta-glycerophsphate and ascorbic acid suppressed activaaton of phosphoinositide-specific phospholipase C (PI-PLC) and phospholipase D (PLD) in response to prostaglandin F_<2alpha> (PGF_<2alpha>) by 20-30% and 15%, respectively. Western blot analyzes with subtype-specific PI-PLC antibodies revealed that in cells treated for 5 days with these differentiation inducers, the levels of PI-PLCbeta1 and PI-PLCbeta3 decreased to 37% and 67% compared to those of undifferentiated control cells, respectively. However, the level of PLC_<gamma>1 and those of protein kinase C isozymes (alpha, beta1, beta2, delta, epsilon, rheta, zeta) remained unaltered. PGF_<2alpha> also stimulated protein tyrosine phosphorilations and activation of mitogen-activated protein (MAP) kinases. These responses were not affected by differentiation induceres. These results suggest that the suppressed expression of PI-PLCbeta1 and PI-PLCbeta3 are closely related to osteoblast cell differentiation.

β-甘油磷酸盐和抗坏血酸的组合增加了碱性磷酸盐（ALP）活性，一种用于成骨细胞分化的Maraker，在克隆成骨细胞中，如细胞系MC3T3-E1。在将这些药物添加到生长培养基中24小时后，该增加的增加是在培养物5天后达到最大水平的24小时。尽管已知已知细胞内环状AMP水平的增加会诱导成骨ACEL的分化，但这些治疗并未引起环状AMP的显着增加。β-甘油苯甲酸酯和抗坏血酸的处理抑制了磷酸磷酸磷酸化磷酸化酶C（pi-Plc）的磷酸化磷酸酶（Pi-Plland）（Prosta）<2 <磷酸化酶> protage <2 （PGF_ <2alpha>）分别为20-30％和15％。使用亚型特异性PI-PLC抗体进行蛋白质印迹分析表明，在用这些分化诱导剂处理5天的细胞中，与未分化的对照细胞相比，PI-PLCBETA1和PI-PLCBETA3的水平分别降至37％和67％。但是，PLC_ <gamma> 1的水平和蛋白激酶C同工酶（Alpha，beta1，beta2，delta，epsilon，rheta，zeta）的水平仍然没有得到改变。 PGF_ <2alpha>还刺激了蛋白质酪氨酸磷脂和促丝分裂原激活蛋白（MAP）激酶的激活。这些反应不受分化诱导剂的影响。这些结果表明，抑制PI-PLCBETA1和PI-PLCBETA3的表达与成骨细胞分化密切相关。