Cholesterol is an essential component of cell membranes and an essential substrate for the synthesis of biologically active signalling molecules, including steroids. Activation of cholesterol requires transport within cells which can have a significant local effect on cellular activity.

In this review, Jefcoate and Lee reframe the perspective of cholesterol trafficking via steroidogenic acute regulatory protein (StAR) by summarising how a new imaging approach can provide an insight into local cell signalling by imaging gene expression in single cells.

Single molecule fluorescence in situ hybridisation of mRNA (sm-FISH) has been developed to complement single cell RNA sequencing (sc-RNASeq) to determine precise 3D positioning of individual cells based on mRNA markers. Use of sm-FISH delivers novel insights into single cell signalling by resolving single RNA molecules as mRNA and by quantifying pre-mRNA at gene loci. The sm-FISH technique allows the spatial relationship of individual cells to be identified by their distinctive expression profiles, and it can be utilised to provide novel insights into cholesterol signalling.

Read the full article in Journal of Molecular Endocrinology 60 R213–R235