The present application discloses the use of light-gated cation-selective channelrhodopsins (Ch Rs) for the optogenetic control of the secretion of a polypeptide of interest in adipocytes. Engineered adipocytes comprising a channelrhodopsin (ChR) polypeptide, and/or a nucleic acid encoding same, and a secretory polypeptide precursor comprising a bioactive polypeptide and a signal peptide suitable for secretion of the bioactive polypeptide by the engineered adipocytes, and/or a nucleic acid encoding same, are disclosed. The use of such engineered adipocytes for the management or treatment of diseases/conditions in which the secretion of a polypeptide of interest is beneficial, such as the secretion of insulin in diabetic patients, is also disclosed.
