甲状旁腺素和胰岛素样生长因子促成骨样细胞ROS 17/2.8增殖分化中的协同作用

 间歇性小剂量地给予甲状旁腺素 (parathyroid hormone,PTH)可促进成骨 .胰岛素样生长因子 - I(insulin- like growth factor- I,IGF- I)由成骨细胞所产生并贮存于骨基质中 ,可促进成骨细胞的增殖分化 .为进一步了解向钙性激素和骨源性生长因子对骨生长的影响 ,利用成骨样细胞 ROS1 7/ 2 .8进行体外实验 ,观察了 PTH和 IGF- I这两种在骨生长和代谢中有重要作用的激素和因子相互作用的效果 ,并对其相互作用机制作出初步探讨 .结果显示 :联合使用 IGF- I及 PTH(间歇性给药 )时 ,(1 ) SRB(sodium rhodamine B,SRB)染色显示经 PTH(1 0 -9mol/ L,间歇给药 )和 IGF- I(1 0 -9mol/ L)联合处理的细胞 ,其数目明显增加 ,且明显高于单独处理组 ;(2 ) 3H- Td R参入增加 ,也明显高于单独处理组 ;(3)与增殖相关的原癌基因 (c- fos,c- jun,c- ki- ras)的表达增强 ,明显高于单独处理组 ;(4)骨钙素 (osteocalcin)基因 m RNA表达增强 ,明显高于单独处理组 ;(5) IGF- I(1 0 -8mol/L,1 0 -9mol/ L)可使 PTH受体基因 m RNA表达增强 .这些结果提示 PTH和 IGF- I在成骨样细胞ROS 1 7/ 2 .8增殖分化中具有协同作用 ,原癌基因的表达增强可能是其作用的一个环节 .此外 ,IGF- I可能通过增强 PTH受体表达 ,使细胞对 PTH的反应性增强

The Synergetic Effect of Parathyroid Hormone and Insulin-like Growth Factor-I on Proliferation and Differentiation in Rat Osteoblast-like ROS 17/2.8 Cells*

It has been reported that parathyroid hormone (PTH) exerts bone forming effects in vivo when administered intermittently.Insulin like growth factor I(IGF I)is produced by osteoblasts and stored in the bone matrix.IGF I stimulates the proliferation and differentiation of osteoblast.To further understand the interaction between calciotropic hormones and those bone derived growth factors in osteoblasts,the interaction between PTH and IGF I in osteoblast like ROS 17/2.8 cells was observed,and the possible explanation of the mechanism was provided.Cells were exposed to IGF I(10 9 mol/L)for three days,meanwhile PTH(10 9 mol/L)was added for the first 6 hours of each day.The results showed that SRB(sodium rhodamine B)assay and 3H TdR incorporations were all significantly enhanced by the combined treatrment of PTH(intermittently)and IGF I.PTH combined with IGF I could also induce the gene expression of proto oncogene( c fos,c jun,c ki ras )and the marker protein of osteoblast osteocalcin gene.Furthermore,the gene expression of PTH receptor could be induced by IGF I.These data suggested that IGF I and PTH might synergistically stimulate proliferation and differentiation in osteoblast like ROS 17/2.8 cells.The enhanced gene expression of proto oncogene probably played a role in the mechanism.IGF I might regulate the response of the osteoblast like cell to PTH via enhancing the PTH receptor gene expression.