DIFFERENTIAL EXPRESSION OF INSULIN-LIKE GROWTH FACTOR-I (IGF-I) AND IGF-II MESSENGER-RIBONUCLEIC-ACID IN GROWING RAT BONE
DIFFERENTIAL EXPRESSION OF INSULIN-LIKE GROWTH FACTOR-I (IGF-I) AND IGF-II MESSENGER-RIBONUCLEIC-ACID IN GROWING RAT BONE
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DOI：
10.1210/en.132.3.1158
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发表时间：
1993-03-01
期刊：
影响因子：
4.8
通讯作者：
WEINREB, M
中科院分区：
文献类型：
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作者：
SHINAR, DM;ENDO, N;WEINREB, M
胰岛素样生长因子（IGF-I和IGF-II）是骨骼中最丰富的生长因子之一。虽然它们的局部产生与生长发育有关，但表达这些蛋白质的细胞的定位并没有很好的文献记载。我们采用原位杂交技术研究了大鼠出生后骨发育不同阶段长骨中IGF-I和IGF-II mRNA的时空表达。在2日龄大鼠中，IGF-II在软骨和骨周围的中胚层结构中高度表达。在骨发育后期，IGF-II信号强度下降，但在3周和5周时仍可在胫骨生长板中检测到。在这一阶段，骨骺生长板内IGF-II信号分布不均匀，外周强于中心，主要集中在生发层和部分（但不是全部）软骨柱。另一方面，igf - 1仅在骨发育的早期软骨阶段的骨膜中被微弱检测到。在后期，igf - 1与干骺端和骨骺的小梁骨以及沿骨膜和骨膜表面的骨化区密切相关。令人惊讶的是，我们在任何时候都没有在骨骺生长板的软骨细胞中检测到IGF-I mRNA。这些结果表明，在大鼠中，IGF-II在骨的早期发育和骨骺板的纵向生长中起作用。IGF-I与成骨区关系更密切，不能替代生长板中IGF-II水平的下降。
Insulin-like growth factors (IGF-I and IGF-II) are among the most abundant growth factors found in bone. Although their local production has been implicated in growth and development, localization of the cells that express these proteins is not well documented. We have studied, by in situ hybridization, the temporal and spatial expression of IGF-I and IGF-II mRNA in rat long bones at different stages of postnatal bone development. In 2-day-old rats, IGF-II was highly expressed in cartilage and in the mesodermal structures that surround the bone. At later stages of bone development, the IGF-II signal decreased in intensity, but could still be detected in the growth plate of tibial bones at 3 and 5 weeks. At this stage, the IGF-II signal in the epiphyseal growth plate was unevenly distributed and was stronger in the periphery than in the center, where it was mainly concentrated in the germinal layer and in some, but not all, cartilage columns. IGF-I, on the other hand, was only faintly detected in the periosteum at the early cartilaginous stage of bone development. At later stages, IGF-I was strongly associated with regions of ossification in the trabecular bone of the metaphysis and epiphysis and along the endosteal and periosteal surfaces. Surprisingly, we did not detect at any time IGF-I mRNA in chondrocytes of the epiphyseal growth plate. These results suggest that in the rat, IGF-II plays a role in early development of bone and in the longitudinal growth of the epiphyseal plate. IGF-I is more closely associated with the osteogenic regions and does not replace the declining levels of IGF-II in the growth plate.