Retinoic acid (Tretinoin), a metabolite of vitamin A, is a natural agonist of the retinoic acid receptor RAR, agonizing RARα/β/γ (IC50=14 nM). Retinoic acid induces cellular differentiation, reduces cellular proliferation, and inhibits tumorigenesis.

RARα:14 nM, RARβ:14 nM, RARγ:14 nM

方法：人单核细胞 THP-1 用 Retinoic acid (10-100 nM) 处理 24 h，使用 Western Blot 方法检测靶点蛋白表达水平。
结果：Retinoic acid 处理的细胞中 RXRα 和 RARα 蛋白持续减少。[1]
方法：小鼠胚胎干细胞 mESC 用 Retinoic acid (1 μM) 处理 24 h，进行基因表达微阵列分析。
结果：Retinoic acid 处理后分化相关基因 Hoxb1、Hoxb2 和 Hoxb3 上调，而多能性相关基因 Oct4、Nanog、Klf4、Esrrb、Lefty1 和 Letfy2 下调。Retinoic acid 诱导ES细胞外胚层标志物表达。[2]

方法：为研究对小鼠齿筋膜兴奋性和抑制性神经传递的影响，将 Retinoic acid (10 mg/kg in Corn oil+5% DMSO) 单次腹腔注射给 C57BL/6J 小鼠。
结果：在给予 Retinoic acid 6 h 后，背侧海马中的自发兴奋性突触后电流频率和突触数量均显著增加。Retinoic acid 介导小鼠齿状颗粒细胞中突触足蛋白依赖性化生。[3]
方法：为检测对小鼠肝脏脂质代谢的影响，将 Retinoic acid (10-100 mg/kg) 皮下注射给 NMRI 小鼠，每天一次，持续四天。
结果：Retinoic acid 治疗可减轻体重和肥胖。Retinoic acid 在体内将肝脏脂质代谢转变为增加分解代谢和减少脂肪生成。[4]

Retinoic acid is dissolved in DMSO and stored, and then diluted with appropriate medium before use[3]. P19 cell are induced to undergo neuronal differentiation according to established procedures. Briefly, cells are cultured on 1% agarose-coated 10 cm dishes at 3×10 5 cells/mL in α-minimal essential medium supplemented with 10% FBS. Differentiation is induced by addition of Retinoic acid (1 μM) and medium containing Retinoic acid replaced 2 days later. On day 4, cell aggregates are collected by centrifugation, separated to single cells by trypsin/EDTA treatment, replated onto poly-L-lysine-coated plates, and cultured in α-minimal essential medium supplemented with 10% FBS. On day 6, medium is replaced with neurobasal medium containing B27 supplement and 2 mM GlutaMAX. Medium is replaced every 2 days for an additional week[3].