Objective

Retinoids are a class of molecules derived from Vitamin A that play key roles in a plethora of cellular processes, including differentiation, by mediating gene transcription in the nucleus. They have become key reagents in the preparation of cell cultures for use in the study of cell biology, and as powerful therapeutic agents. However, despite this, much is still to be learnt about the complex signalling pathway that governs their action. Endogenous retinoids like all-trans-retinoic acid (ATRA) are very vulnerable to photodegradation and isomerism due to their polyene structure, making their use as a research tool inherently uncertain. We have developed synthetic analogues of ATRA that are not only stable towards light, but are intrinsically fluorescent. These fluorescent retinoids can be uniquely imaged in a cellular environment using fluorescence microscopy – a property that has been exploited to reveal fascinating insights into their mode of action. Furthermore, their unique properties have enabled the development of a range of in vitro research tools, including a novel fluorometric binding assay. Our fluorescent retinoids can now be used to shed light on a signalling pathway that holds immense therapeutic potential, and whose influence is felt throughout the human body.