Quantitative Imaging of Protein and Lipid Metabolism using Stimulated Raman Scattering Microscopy

Abstract

Protein and lipid metabolisms play critical roles in cellular function, and their dysregulation is associated with a range of diseases. Novel techniques for visualizing and quantifying protein and lipid metabolic activities can provide valuable insights into their underlying mechanisms. Stimulated Raman scattering (SRS) microscopy is a powerful label-free quantitative optical technique that enables the mapping of molecular distributions in inhomogeneous biological specimens, such as cells and tissues, by probing their intrinsic vibrational frequencies. This dissertation presents advancements in implementing multi-channel SRS microscopy and its applications for quantifying several cellular activities related to protein and lipid metabolism. Specifically, it describes accurate measurements of single-cell growth rates and drug uptake in both two-dimensional and three-dimensional cell environments, classification of lipid molecules in tissues affected by nonalcoholic fatty liver disease, and detection of oxidation products of polyunsaturated fatty acids during lipid peroxidation-induced cell ferroptosis. These advancements in SRS microscopy offer significant potential for understanding the complex mechanisms that regulate protein and lipid metabolic activities and developing targeted treatments for various diseases.