Graphical AbstractHigh-resolution stimulated Raman scattering (SRS) imaging of a genetically engineered model (GEM) enables metabolite imaging in a yeast model and uncovers an unexpected regulatory mechanism of sterol metabolism, providing new insights underpinning the distributional and functional importance of sterol in cells. SRS-GEM demonstrates a promising platform to explore unknown metabolic mechanisms beyond the reach of conventional approaches.

Cholesterol is connected to multiple health problems. Although the biochemical pathway is well-understood, many disease-related mechanisms, such as subcellular regulation of cholesterol synthesis, are still unclear. It presents a grand challenge for conventional characterization methods, which have difficulties providing non-invasive, high-speed, and high-resolution measurements of metabolites in living cells. Stimulated Raman scattering (SRS) can selectively visualize metabolic biomolecules based on vibrational spectroscopic features. Here, by SRS imaging of subcellular sterol, we found an unconventional regulatory mechanism based on the distribution of sterols on the plasma membrane and lipid droplets. The combination of vibrational imaging and genetic modulation promises great potential in finding new regulatory mechanisms, which would open opportunities for diagnosing and prognosis of cholesterol-related diseases.