CORRELATION BETWEEN MESSENGER-RNA LEVELS FOR BONE CELL-PROTEINS AND BONE-FORMATION IN LONG BONES OF MATURING RATS
CORRELATION BETWEEN MESSENGER-RNA LEVELS FOR BONE CELL-PROTEINS AND BONE-FORMATION IN LONG BONES OF MATURING RATS
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DOI：
10.1152/ajpendo.1991.261.3.e348
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发表时间：
1991-09-01
影响因子：
--
通讯作者：
SPELSBERG, TC
中科院分区：
文献类型：
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作者：
TURNER, RT;SPELSBERG, TC
本报告描述了骨形成与选定骨蛋白mRNA水平之间的关系。采用动态骨组织形态测定法对断奶（3周）至52周龄雄性大鼠胫骨骨膜骨形成情况进行了测定。对新分离的长骨骨膜细胞进行Northern blot分析，以确定糖酵解酶甘油醛-3-磷酸脱氢酶（GAP）、骨基质蛋白骨钙素（BGP）和1型前胶原（胶原）的pre - α -2(I)链、成骨细胞标记酶碱性磷酸酶（AP）和成骨细胞衍生信号因子（生长因子）转化生长因子- β (tgf - β)的稳态mRNA水平。胫骨骨干桡骨生长在8周龄时达到最大值，此后随年龄增长逐渐下降。这种与年龄相关的径向生长速率下降最初是由于成骨细胞活性降低；然而，在年龄较大的大鼠（bb0 - 17周龄）中，成骨细胞数量减少导致骨形成减少。胶原mRNA的稳态表达水平与骨膜成骨率有较强的相关性。相比之下，其他骨蛋白的mRNA水平相关性较弱（tgf - β和AP）或不相关（BGP）。这些结果表明，成熟大鼠长骨骨膜细胞骨基质合成减少是由于骨基质蛋白基因表达减少所致。
This report describes the relationship between bone formation and mRNA levels for selected bone proteins. Dynamic bone histomorphometry was used to measure bone formation in tibial periosteum of male rats from weanling (3 wk) to 52 wk old. Northern blot analysis of freshly isolated periosteal cells from the long bones was used to determine steady-state mRNA levels for the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAP), the bone matrix proteins osteocalcin (BGP), and prepro alpha-2(I) chain of type 1 precollagen (collagen), the osteoblast marker enzyme alkaline phosphatase (AP), and the osteoblast-derived signaling factor (growth factor) transforming growth factor-beta (TGF-beta). Radial growth at the tibial diaphysis achieved a maximum value in 8-wk-old rats and decreased progressively with age thereafter. This age-related decrease in the radial growth rate was initially due to reduced osteoblast activity; however, in older rats (> 17 wk old) reduced osteoblast number contributed to the decrease in bone formation. There was a strong correlation between the steady-state mRNA level for collagen and the periosteal bone formation rate. In contrast, the mRNA levels for the other bone proteins were more weakly correlated (TGF-beta and AP) or not correlated (BGP). These results suggest that the decreased bone matrix synthesis by periosteal cells in long bones of maturing rats is due to decreased expression of genes for bone matrix proteins.