CHANGING PATTERNS OF THE RETINOIC ACID SYSTEM IN THE DEVELOPING RETINA
CHANGING PATTERNS OF THE RETINOIC ACID SYSTEM IN THE DEVELOPING RETINA
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DOI：
10.1006/dbio.1993.1197
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发表时间：
1993-08-01
影响因子：
2.7
通讯作者：
DRAGER, UC
中科院分区：
文献类型：
--
作者：
MCCAFFERY, P;POSCH, KC;DRAGER, UC
在胚胎大鼠和鸡的视网膜中，如在小鼠中一样，视黄酸的合成由背侧和腹侧部分中的不同酶介导，腹侧途径产生更高的视黄酸水平。在小鼠中，先前发现背侧酶是醛脱氢酶1类亚型AHD-2，腹侧酶是未知的酸性脱氢酶活性。这种酸性脱氢酶活性现在显示出由早期和后期表达形式组成，早期形式与早期胚胎躯干和心脏区域的活性无法区分。酸性脱氢酶在眼睛中的表达首先在视小凹阶段（E8.0）检测到，在视泡中出现AHD-2的前一天。在胚胎和出生后早期阶段，酸性脱氢酶占视网膜中视黄酸合成的大部分;在出生后后期阶段，它消失，并且在成人视网膜中，所有视黄酸合成都由AHD-2介导。小鼠中的HPLC测量显示高水平的全反式和13-顺式视黄酸：在E14时，视网膜总共含有约0.5 μ M视黄酸，而成人视网膜中的水平约低四倍。背腹不对称性也延伸到细胞视黄酸结合蛋白CRABP I，它首先出现在中央视网膜的早期分化的神经节细胞中，并在后来的胚胎中短暂地表现出一种腹背后退的表达模式。
In retinas of embryonic rat and chick, as in the mouse, synthesis of retinoic acid is mediated by different dehydrogenases in dorsal and ventral portions, with the ventral pathways generating higher retinoic acid levels. In the mouse, the dorsal enzyme was previously found to be the aldehyde dehydrogenase class-1 isoform AHD-2 and the ventral enzyme an unknown acidic dehydrogenase activity. This acidic dehydrogenase activity is now shown to consist of an early and a later expressed form, with the early form being indistinguishable from the activity in the early embryonic trunk and heart regions. Expression of the acidic dehydrogenase in the eye is first detected at the optic pit stage (E8.0), a day before the appearance of AHD-2 in the optic vesicle. The acidic dehydrogenase accounts for most of the retinoic acid synthesis in the retina during embryonic and early postnatal stages; during later postnatal stages it disappears and in the adult retina all retinoic acid synthesis is mediated by AHD-2. HPLC measurements in mice show high levels of all-trans- and 13-cis-retinoic acid: at E14 the retina contains a total of about 0.5 μMretinoic acid, and levels in the adult retina are about fourfold lower. The dorso-ventral asymmetry extends also to the cellular retinoic acid binding protein CRABP I, which first appears in the early differentiating ganglion cells in central retina and in the later embryo shows transiently a ventro-dorsally receding pattern of expression.