Session: Rising Stars of Mechanical Engineering Celebration & Showcase

Paper Number: 150013

150013 - Raman Spectroscopy for Lipidomic Profiling With Single-Cell Resolution 

Single-cell omics are the key to understanding phenotypic heterogeneity in multifactorial diseases such as cancer and Alzheimer’s disease. The way that biologists evaluate cellular heterogeneity in intricate samples has been completely changed by single-cell omics technology. However, because the proteome and metabolome cannot be amplified similarly to nucleic acids, single-cell proteomics and metabolomics have lagged behind genomic advances, necessitating the employment of exceedingly sensitive detection tools. Multiplexed immunofluorescence imaging and other spatial approaches that examine protein expression frequently have coverage limits of 20–100 proteins, whereas imaging mass spectrometry and other techniques do not yet have the sensitivity to assess the proteome/metabolome with high spatial resolution. Further, classical lipidome/metabolome analysis using LC-MS results in the loss of spatial information due to tissue homogenization and sample extraction requirements. In this poster, I will present how Raman microscopy is a solution to this roadblock. Raman imaging is a non-invasive optical technique that examines the vibrational movements of chemical bonds and enables label-free detection of endogenous metabolites. In an untargeted manner, Raman fingerprinting has been used to identify a variety of biological metabolites, such as nucleic acids, amino acids, lipids, glucose, and neurotransmitters. Raman microscopy creates subcellular chemical maps in addition to spectroscopy by focusing on specific vibrational peaks, even using FFPE tissue samples. Moreover, I will present several case studies where single-cell metabolomics has been successfully applied to address important biological questions. These examples will showcase how single-cell metabolomics has shed light on metabolic heterogeneity, cellular responses to environmental cues, developmental processes, and disease progression. Overall, this talk aims to highlight the transformative impact of single-cell metabolomics in unraveling the complexity of cellular metabolism.

Further, we will explore lipid peroxidation-based cell death using this approach. Cell death is a crucial physiological process. The resistance of cancer cells to therapeutic drugs is a significant barrier to successful cancer treatment and the primary factor in cancer recurrence. Activation of novel cell death pathways would resensitize drug-resistant cells to chemotherapy. Ferroptosis is a nonapoptotic cell death activated when the lipid in the cell undergoes iron-dependent peroxidation. Our overarching goal is to investigate lipid metabolism-driven cell death through the modulation of ferroptosis in cell culture and in vivo models of drug-resistant cancer. The results will provide fundamental insights into the molecular chemistry of ferroptosis and its role in disease pathology by developing a multi-omics approach with single-cell resolution. Diseases like cancer, sepsis, pre-eclampsia, diabetes, cardiovascular disease, and neurodegenerative illnesses correlate with lipids and lipid metabolism dysregulation. Lipid distributions are heterogeneous, and their chemical modifications, such as lipid peroxidation, are potentially crucial for disease onset and progression. However, the precise relationship between lipid distribution and their chemical modification and disease pathology is not fully understood. This project investigates changes in lipid distribution and lipid peroxidation both in vitro and in tissues to provide fundamental insights into their molecular chemistry and its role in disease pathology by using the experimental methods developed in our group based on spatial chemical imaging. Our approach uses Raman imaging to provide spatial information about lipids in the defined cellular compartments in contrast to the bulk or fractionated examinations of extracted lipids provided by liquid chromatography-mass spectrometry (LC-MS). This proposal builds upon our prior success in performing spatial imaging of lipid distribution in cells and tissues. The hypotheses underlying this effort are that (a) there are significant heterogeneities in lipid distributions and their chemical modifications, and (b) these heterogeneities can be correlated to the pathology of the disease. In particular, we will: 1) Investigate the effect of ferroptosis on the lipid metabolism and iron metabolism of drug-resistant cell lines in 2D culture; 2) Perform spatial mapping and profiling of lipids during ferroptosis in 3D cell culture; 3) Detect ferroptosis and identify its associated mechanism in vivo. The project outcomes will improve our understanding of the molecular mechanism, disease phenotype, and disease progression leading to better therapeutic strategies.

Presenting Author: Manas Ranjan Gartia Louisiana State University

Presenting Author Biography: Dr. Manas Ranjan Gartia is currently an Associate Professor in the Department of Mechanical and Industrial Engineering at LSU. He received his Ph.D. degree from the University of Illinois at Urbana-Champaign (UIUC) in 2013 and joined LSU as an Assistant Professor in the Department of Mechanical and Industrial Engineering in 2015. Dr. Gartia’s group has recently developed high-resolution Raman microscopy-based analytical methods for spatial lipidomics imaging. The developed approach will be used to study lipid and metabolomic changes in plant cells and tissues in response to different stresses (salt, water, drought). He has published over 100 journal and conference papers as well as 8 patents (issued/pending). Dr. Gartia is the recipient of several awards, including the NIH MIRA Award in 2023, NSF CAREER Award in 2021, LSU Alumni Association Rising Faculty Research Award in 2017, Outstanding Research Achievement award (best PhD) from the College of Engineering at the University of Illinois in 2014, Vodafone Wireless Innovation Award in 2013, Nokia Sensing XChallenge distinguished award in 2013, and Sargent & Lundy LLC fellowship in 2009. His work on colorimetric nano-plasmonic sensors and mobile phone water nano-sensor was featured in Forbes Magazine, The Wall Street Journal, The Wired Magazine, The Huffington Post, and exhibited at the Hewitt Cooper Museum (part of the Smithsonian) in NY. His recent work on breast cancer gene detection using a smartphone was also highlighted by local TV channels such as WBRZ, WAFB, LPB, and the local newspaper The Advocate.

Authors:

Manas Ranjan Gartia Louisiana State University
Elnaz Sheikh Louisiana State University
Maria Iftesum Louisiana State University
Kirti Agrawal Louisiana State University