title: D38-cholesterol as a Raman active probe for imaging intracellular cholesterol storage.
abstract: We generated a highly deuterated cholesterol analog (D38-cholesterol) and demonstrated its use for selective vibrational imaging of cholesterol storage in mammalian cells. D38-cholesterol produces detectable signals in stimulated Raman scattering (SRS) imaging, is rapidly taken up by cells, and is efficiently metabolized by acyl-CoA cholesterol acyltransferase to form cholesteryl esters. Using hyperspectral SRS imaging of D38-cholesterol, we visualized cholesterol storage in lipid droplets. We found that some lipid droplets accumulated preferentially unesterified D38-cholesterol, whereas others stored D38-cholesteryl esters. In steroidogenic cells, D38-cholesteryl esters and triacylglycerols were partitioned into distinct sets of lipid droplets. Thus, hyperspectral SRS imaging of D38-cholesterol demonstrates a heterogeneous incorporation of neutral lipid species, i.e., free cholesterol, cholesteryl esters, and triacylglycerols, between individual lipid droplets in a cell.
authors.affiliation: University of California, Irvine, Department of Biomedical Engineering, Irvine, California 92697, United States.
authors.forename: Alba
authors.initials: A
authors.lastname: Alfonso-García
authors.affiliation: University of Helsinki, Finland and Minerva Foundation Institute for Medical Research, Department of Anatomy and Research Programs Unit, Faculty of Medicine, Helsinki 00290, Finland.
authors.forename: Simon G
authors.initials: SG
authors.lastname: Pfisterer
authors.affiliation: University of Geneva, NCCR Chemical Biology, Department of Biochemistry, CH-1211 Geneva, Switzerland.
authors.forename: Howard
authors.initials: H
authors.lastname: Riezman
authors.affiliation: University of Helsinki, Finland and Minerva Foundation Institute for Medical Research, Department of Anatomy and Research Programs Unit, Faculty of Medicine, Helsinki 00290, Finland.
authors.forename: Elina
authors.initials: E
authors.lastname: Ikonen
authors.affiliation: University of California, Irvine, Department of Chemistry, Irvine, California 92697, United States.
authors.forename: Eric O
authors.initials: EO
authors.lastname: Potma
mesh_terms: D002784:Cholesterol / Q000378:metabolism*; D003903:Deuterium / Q000493:pharmacokinetics*; D015336:Molecular Probe Techniques; D015335:Molecular Probes / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013347:Subcellular Fractions / Q000378:metabolism*
chemical_list: D015335:Molecular Probes; D002784:Cholesterol; D003903:Deuterium