CELLULAR-PATTERN OF INSULIN-LIKE GROWTH FACTOR-I (IGF-I) AND TYPE-I IGF RECEPTOR GENE-EXPRESSION IN EARLY ORGANOGENESIS - COMPARISON WITH IGF-II GENE-EXPRESSION
CELLULAR-PATTERN OF INSULIN-LIKE GROWTH FACTOR-I (IGF-I) AND TYPE-I IGF RECEPTOR GENE-EXPRESSION IN EARLY ORGANOGENESIS - COMPARISON WITH IGF-II GENE-EXPRESSION
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DOI：
10.1210/mend-4-9-1386
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发表时间：
1990-09-01
影响因子：
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通讯作者：
LEROITH, D
中科院分区：
文献类型：
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作者：
BONDY, CA;WERNER, H;LEROITH, D
为了研究胰岛素样生长因子（IGF）在胚胎发生中的潜在作用，我们使用原位杂交组织化学方法定位了大鼠胚胎发育早期（胚胎14和15天）IGF-I、IGF- ii和I型IGF受体的mrna。IGF-I和IGF-II mrna的细胞分布模式明显不同。在萌芽神经和脊髓神经节附近的未分化间质组织中，以及与三叉神经靶区相对应的发育面限定区域中，IGF-I mRNA尤其丰富。IGF-I mRNA也存在于周围间质聚集物中，但不存在于发育中的肌肉和软骨中。IGF-I mRNA选择性地集中在活跃的组织重塑区域，如心脏流出道，而在器官发生的早期阶段，肝脏、垂体和神经系统中检测不到。IGF-II mRNA在发育中的肌肉、软骨和血管组织以及胚胎肝脏和垂体中含量丰富。IGF-II mRNA在与脑交界的脉络膜丛、终板血管间质等部位也有明显表达。I型IGF受体的信使RNA广泛分布于胚胎组织中，但最高水平见于后脑腹底板，在那里专门的神经上皮细胞作为轴突靶向的向导。综上所述，IGF-I和IGF-II基因的不同细胞表达模式表明这两种igf受到不同的调控，因此在胚胎发育过程中可能具有显著不同的作用。此外，i型IGF受体基因的早期和广泛表达，与IGF- i基因的相对有限和局部表达模式相反，这与该受体可能介导胚胎发生过程中IGF- ii和IGF- i的作用的观点一致。
To investigate the potential role(s) of the insulin-like growth factors (IGFs) in embryogenesis, we have used in situ hybridization histochemistry to localize mRNAs for IGF-I, IGF-II, and the type I IGF receptor during an early period in rat embryonic development (embryonic days 14 and 15). IGF-I and IGF-II mRNAs were found in distinctly different patterns of cellular distribution. IGF-I mRNA was particularly abundant in undifferentiated mesenchymal tissue in the vicinity of sprouting nerves and spinal ganglia, and in circumscribed regions of the developing face that corresponded to the target zones of the trigeminal nerve. IGF-I mRNA was also found in aggregations of mesenchyme surrounding, but not in developing muscle and cartilage. IGF-I mRNA was selectively concentrated in areas of active tissue remodeling, such as the cardiac outflow tract, and was undetectable in liver, pituitary, and nervous system at this early stage of organogenesis. IGF-II mRNA was abunant in developing muscle, cartilage, and vascular tissue, and in the embryonic liver and pituitary. IGF-II mRNA was also conspicuous in areas of vascular interface with the brain, such as the choroid plexus and the organum vasculosum of the lamina terminalis. Messenger RNA for the type I IGF receptor was widely distributed in embryonic tissues, but the highest levels were seen in the ventral floorplate of the hindbrain, where specialized neuroepithelial cells act as guides for axonal targeting. In conclusion, the different cellular patterns of expression of genes for IGF-I and IGF-II indicate that these two IGFs are differently regulated and, thus, may have significantly different roles in the process of embryonic development. Furthermore, the early and widespread expression of the type-I IGF receptor gene, in contrast to the relatively limited and localized pattern of IGF-I gene expression, is consistent with the view that this receptor may mediate the effects of IGF-II as well as IGF-I during embryogenesis.