Retinoid-binding proteins in the cerebellum and choroid plexus and their relationship to regionalized retinoic acid synthesis and degradation.
Retinoid-binding proteins in the cerebellum and choroid plexus and their relationship to regionalized retinoic acid synthesis and degradation.
复制标题
小脑和脉络丛中的类视黄醇结合蛋白及其与区域性视黄酸合成和降解的关系。
DOI：
10.1046/j.1432-1327.1998.2570344.x
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
McCaffery,P
中科院分区：
文献类型：
--
作者：
Yamamoto,M;Dräger,UC;Ong,DE;McCaffery,P
研究了细胞视黄酸结合蛋白（CRABP）和细胞视黄醇结合蛋白（CRBP）在发育中的小鼠小脑和第四脑室脉络丛中的表达及其与视黄酸（RA）合成和降解的关系。脉络丛表达合成RA的视网膜醛脱氢酶RALDH-2，可能是RA在紧密贴壁小脑的扩散源，调节其发育。我们发现CRBP在脉络丛中表达，并且在体外试验中，将重组CRBP添加到RALDH-2中增加了由视黄醇合成的RA，增加的量取决于CRBP/视黄醇比率。根据其等电点表征RA结合蛋白的技术显示CRABP I和CRABP II均存在于小脑和P19细胞中，并且仅CRABP II存在于脉络丛中。利用该技术，CRABP I也可以在HL 60细胞系中检测到。除了两种已知的酸性RA结合蛋白CRABP I和II外，小脑还表达了第三种RA结合蛋白，可通过其中性等电点区分;在嗅球，肾脏和睾丸中也检测到相同的结合蛋白。我们使用RA结合技术来跟踪结合RA从小脑的消除速率。向出生后第1天的小鼠全身注射0.3μ mol RA，8小时后几乎完全清除。这些结果表明，类维生素A结合蛋白可能通过其调节小脑和脉络丛中RA合成和catalysts的平衡的机制。
The expression of cellular retinoic‐acid‐binding protein (CRABP) and cellular retinol‐binding protein (CRBP), as well as their relationship to retinoic acid (RA) synthesis and degradation were examined in the developing mouse cerebellum and choroid plexus of the fourth ventricle. The choroid plexus, which expresses the RA‐synthesizing retinaldehyde dehydrogenase RALDH‐2, is likely to represent a diffusion source of RA for the closely apposed cerebellum, regulating its development. We found CRBP to be expressed in the choroid plexus and, in anin‐vitroassay, addition of recombinant CRBP to RALDH‐2 increased RA synthesis from retinaldehyde, with the amount of increase depending on the CRBP/retinaldehyde ratio. A technique that characterizes RA‐binding proteins according to their isoelectric point showed both CRABP I and CRABP II to be present in the cerebellum and P19 cells, and only CRABP II to be present in the choroid plexus. With this technique, CRABP I could also be detected in the HL60 cell line. In addition to the two known acidic RA‐binding proteins CRABP I and II, the cerebellum expressed a third RA‐binding protein distinguishable by its neutral isoelectric point; the same binding protein was also detected in the olfactory bulb, kidney and testes. We used the RA‐binding technique to follow the rate of elimination of bound RA from the cerebellum. A systemic injection of 0.3 μmols RA into postnatal day‐1 mice was almost completely removed after 8 hours. These results suggest mechanisms by which the retinoid‐binding protein may regulate the equilibrium of RA synthesis and catabolism in the cerebellum and choroid plexus.