视黄酸信号
中文名称
通路描述
视黄酸信号维生素 A（视黄醇）可代谢为具有活性的视黄酮代谢物，它们既可作为视觉中的发色团，也可在转录和转录后水平中调节基因表达。受视黄酸调控的基因对于繁殖、胚胎发育、生长以及成体中的多个过程（包括能量平衡、神经发生和免疫反应）至关重要。作为视觉循环辅因子的视黄酸是 11-顺式视黄醛（11cRAL）。视黄醇的非视觉循环效应由视黄酸（RA）介导，该视黄酸由视黄醇通过两步转化生成（Napoli 2012）。全反式视黄酸（atRA）是视黄醇的主要激活代谢物。一种异构体 9-顺式视黄酸（9cRA）具有生物活性，但在体内未检测到，除非在胰腺中。另一种途径涉及 BCO1 酶解类胡萝卜素生成视黄醛，随后在肠道中被还原为视黄醇（Harrison 2012）。两种 RA 异构体作为视黄酸受体（RAR）的配体，调节基因表达。（Das et al. 2014）。RA 被 CYP 家族酶代谢为氧化代谢物，如 4-羟基 -、18-羟基 - 或 4-氧基 -RA，这些代谢物随后成为相 II 结合酶的底物（Ross & Zolfaghari 2011）。
英文描述
Signaling by Retinoic Acid Vitamin A (retinol) can be metabolised into active retinoid metabolites that function either as a chromophore in vision or in regulating gene expression transcriptionally and post-transcriptionally. Genes regulated by retinoids are essential for reproduction, embryonic development, growth, and multiple processes in the adult, including energy balance, neurogenesis, and the immune response. The retinoid used as a cofactor in the visual cycle is 11-cis-retinal (11cRAL). The non-visual cycle effects of retinol are mediated by retinoic acid (RA), generated by two-step conversion from retinol (Napoli 2012). All-trans-retinoic acid (atRA) is the major activated metabolite of retinol. An isomer, 9-cis-retinoic acid (9cRA) has biological activity, but has not been detected in vivo, except in the pancreas. An alternative route involves BCO1 cleavage of carotenoids into retinal, which is then reduced into retinol in the intestine (Harrison 2012). The two isomers of RA serve as ligands for retinoic acid receptors (RAR) that regulate gene expression. (Das et al. 2014). RA is catabolised to oxidised metabolites such as 4-hydroxy-, 18-hydroxy- or 4-oxo-RA by CYP family enzymes, these metabolites then becoming substrates for Phase II conjugation enzymes (Ross & Zolfaghari 2011).
所含基因
19 个基因