Ontogeny of preproenkephalin mRNA expression in the rat retina
Ontogeny of preproenkephalin mRNA expression in the rat retina
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DOI：
10.1017/s0952523800008580
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发表时间：
1996-07-01
影响因子：
1.9
通讯作者：
Zagon, IS
中科院分区：
文献类型：
--
作者：
Isayama, T;McLaughlin, PJ;Zagon, IS
内源性阿片系统（即阿片肽和阿片受体）调节新生哺乳动物视网膜的发育事件。本研究对大鼠视网膜发育和成熟过程中编码前脑啡肽原A（PPE）的mRNA进行了研究。PPE是阿片样生长因子（OGF）的前激素，[Met（5）]-脑啡肽。北方分析表明，在发育和成年视网膜中存在一个1.4 kb的信息对应于大鼠PPE mRNA。定量分析表明，PPE信息在出生后第1天以成人水平的5%存在，并在发育过程中增加，直到出生后第27天达到成人数量。原位杂交实验首先检测到PPE mRNA的存在下，在视网膜组织在妊娠晚期。在产前晚期和新生儿视网膜中，PPE信息与含有增殖神经母细胞和有丝分裂后细胞的发育视网膜区域相关。在发育后期，信息似乎主要位于内层视网膜内，丰富的PPE mRNA与内核层（INL）的假定水平细胞相关。成人视网膜表现出类似的模式PPE基因表达的细胞中的INL。这些发现证明，PPE在视网膜中的基因表达始于胎儿，在视网膜发育期间持续，并且与在视网膜个体发育期间调节DNA合成的PPE mRNA衍生物（[Met（5）]-脑啡肽）的存在相一致。我们的研究结果也是第一个显示PPE信息在成年哺乳动物视网膜中的存在，表明阿片样物质基因在成熟的视觉系统中的转录。
Endogenous opioid systems (i.e. opioid peptides and opioid receptors) modulate developmental events in the neonatal mammalian retina. In the present study, the mRNA encoding preproenkephalin A (PPE), the prohormone for the opioid growth factor (OGF), [Met(5)]-enkephalin, was studied in the developing and the adult retinas of rats. Northern analysis indicated the presence of a 1.4-kb message in the developing and adult retinas corresponding to rat PPE mRNA. Quantitation showed that PPE message was present on postnatal day 1 at 5% of the adult level, and increased during development until the adult quantity was reached by postnatal day 27. In situ hybridization experiments first detected the presence of PPE mRNA in retinal tissues during late gestation. In late prenatal and neonatal retinas, PPE message was associated with areas of the developing retina containing proliferating neuroblasts and postmitotic cells. Later in development, message appeared to be located primarily within the inner retina, with abundant PPE mRNA associated with putative horizontal cells of the inner nuclear layer (INL). The adult retina showed a similar pattern of PPE gene expression in the cells of the INL. These findings document that the gene expression in the retina for PPE begins in the fetus, continues during retinal development, and coincides with the presence of a PPE mRNA derivative ([Met(5)]-enkephalin) that regulates DNA synthesis during retinal ontogeny. Our results are also the first to show the presence of PPE message in the adult mammalian retina, suggesting transcription of an opioid gene in the mature visual system.