5-HT3 receptors: potential of individual isoforms for personalised therapy

Serotonin type 3 (5-HT3) receptors are ligand-gated ion channels built by five subunits of diverse composition. In humans, five subunits exist (5-HT3A-E) which are encoded by the genes HTR3A–E and are expressed in various isoforms. Recently, the importance of factors influencing receptor expression became clear, such as chaperones and microRNAs.Owing to their expression profile and physiological functions, 5-HT3 receptors have been implicated in irritable bowel syndrome (IBS) and psychiatric disorders. Interestingly, HTR3 variants have now been shown to be associated with these conditions. This underlines the potential of 5-HT3 receptors as therapeutic targets and may enable personalised therapies in the future.