Important key players in the regulatory machinery within the cells are nuclear retinoid X receptors (RXRs), which compose heterodimers in company with several diverse nuclear receptors, playing a role as ligand inducible transcription factors. In general, nuclear receptors are ligand-activated, transcription-modulating proteins affecting transcriptional responses in target genes. RXR molecules forming permissive heterodimers with disparate nuclear receptors comprise peroxisome proliferator-activated receptors (PPARs), liver X receptors (LXRs), farnesoid X receptor (FXR), pregnane X receptor (PXR) and constitutive androstan receptor (CAR). Retinoid receptors (RARs) and thyroid hormone receptors (TRs) may form conditional heterodimers, and dihydroxyvitamin D₃ receptor (VDR) is believed to form nonpermissive heterodimer. Thus, RXRs are the important molecules that are involved in control of many cellular functions in biological processes and diseases, including cancer or diabetes.

This article summarizes both naturally occurring and synthetic ligands for nuclear retinoid X receptors and describes, predominantly in mammals, their role in molecular mechanisms within the cells. A focus is also on triorganotin compounds, which are high affinity RXR ligands, and finally, we present an outlook on human microbiota as a potential source of RXR activators. Nevertheless, new synthetic rexinoids with better retinoid X receptor activity and lesser side effects are highly required.

细胞内调节机制的重要关键参与者是核维甲酸X受体（RXRs），它与几种不同的核受体一起构成异二聚体，起配体诱导转录因子的作用。通常，核受体是配体激活的转录调节蛋白，可影响靶基因的转录反应。与不同的核受体形成许可的异源二聚体的RXR分子包括过氧化物酶体增殖物激活受体（PPAR），肝X受体（LXR），法呢类X受体（FXR），孕烷X受体（PXR）和组成型雄烷受体（CAR）。类视黄醇受体（RARs）和甲状腺激素受体（TRs）可能形成条件性异二聚体和二羟基维生素D ₃据信受体（VDR）形成非许可的异二聚体。因此，RXR是重要分子，参与许多生物过程和疾病（包括癌症或糖尿病）中的细胞功能控制。

本文总结了天然存在的和合成的核类视黄醇X受体配体，并主要在哺乳动物中描述了它们在细胞内分子机制中的作用。焦点还集中在三有机锡化合物上，它们是高亲和力的RXR配体，最后，我们对人类微生物群作为RXR激活剂的潜在来源提出了展望。然而，高度需要具有更好的类维生素A X受体活性和较小副作用的新的合成类维生素。