HOME
Return to Table of Contents
MONITORING CHANGES IN LIPID METABOLISM IN LIVING HUMAN HEPATOMA CELLS EXPRESSING HCV CORE USING COHERENT ANTI-STOKES RAMAN SCATTERING (CARS) MICROSCOPY
RK Lyn, JP Pezacki
Department of Chemistry, University of Ottawa and National Research Council of Canada, Ottawa, ON
Coherent anti-Stokes Raman scattering (CARS) microscopy is a modern technique that introduces high sensitivity and chemical specificity for imaging tissue in biological systems. A strong resonant CARS signal is generated from excitation of Raman-molecular vibrations stimulated by two laser pulse frequencies coherently focused on a cellular sample. CARS microscopy captures the vibrational stretching of C-H chemical bonds that are abundant in aliphatic biomolecules displayed in three-dimensional spatial resolution. Utilizing the molecular signatures of tissues in living cells circumvents perturbative labeling or chemical treatments. CARS has proven to be an exquisite tool for imaging lipids in living cells and tissues. We have applied CARS microscopy to the study of host-virus interactions in the hepatitic C virus (HCV) in living cells. The core protein induces an increase accumulation of lipid droplets by perturbing host cell lipid metabolism. By incorporating a vector expressing core and green fluorescent protein (GFP) in human hepatoma cell lines, morphological changes in cells expressing GFP are captured by combining CARS and two-photon fluorescence microscopy. Here, through 3-D sectional capability, we visualize and quantify the increase in lipid droplets in live cells expressing HCV core protein. The sensitivity of this technique provides a novel route to understanding the relationship of HCV viral proteins and the development of liver steatosis in chronic HCV infection.