Evaluating pathological levels of intracellular cholesterol through Raman and surface-enhanced Raman spectroscopies

Year: 2024

Authors: Baria E., Dallari C., Mattii F., Pavone F.S., Credi C., Cicchi R., Morrone A., Capitini C., Calamai M.

Autors Affiliation: European Lab Nonlinear Spect LENS, I-50019 Sesto Fiorentino, Italy; Univ Florence, Dept Phys & Astron, I-50019 Sesto Fiorentino, Italy; CNR, Natl Inst Opt, I-50019 Sesto Fiorentino, Italy; Meyer Childrens Hosp IRCCS, Dept Neurosci & Med Genet, Lab Mol Genet Neurometab Dis, Florence, Italy; Univ Florence, Dept Neurosci Psychol Drug Res & Child Hlth NEUROF, Florence, Italy.

Abstract: Versatile methods for the quantification of intracellular cholesterol are essential for understanding cellular physiology and for diagnosing disorders linked to cholesterol metabolism. Here we used Raman spectroscopy (RS) and surface-enhanced Raman spectroscopy (SERS) to measure changes in cholesterol after incubating human fibroblasts with increasing concentrations of cholesterol-methyl-beta-cyclodextrin. RS and SERS were sensitive and accurate enough to detect high levels of cholesterol in fibroblasts from patients affected by type C Niemann-Pick disease (NPC), a lysosomal storage disorder characterized by the primary accumulation of cholesterol. Moreover, SERS was able to distinguish between fibroblasts from different NPC patients, demonstrating higher accuracy than RS and standard fluorescent labeling of cholesterol with filipin III. We show that the type of gold nanoparticles used as signal enhancer surfaces in our SERS measurements are internalized by the cells and are eventually found in lysosomes, the main site of accumulation of cholesterol in NPC fibroblasts. The higher sensitivity of SERS can thus be attributed to the specific trafficking of our gold nanoparticles into these organelles. Our results indicate that RS and SERS can be used as sensitive and accurate methods for the evaluation of intracellular cholesterol content, allowing for the potential development of an optical detection tool for the ex-vivo screening and monitoring of those diseases characterized by abnormal modification in cholesterol levels.

Journal/Review: SCIENTIFIC REPORTS

Volume: 14 (1)      Pages from: 28566-1  to: 28566-11

More Information: This research was funded by Regione Toscana (Bando Salute 2018) for the project Lysolate. We gratefully thank the AMMeC (Associazione Malattie Metaboliche e Congenite, Italia) and the Cell Line and DNA Biobank from Patients Affected by Genetic Diseases, member of the Telethon Network of Genetic Biobanks funded by Telethon Italy, for providing the fibroblasts. Financial support was also provided by the Integrated infrastructure initiative in photonic and quantum sciences – I-PHOQS project financed by the EU next generation PNRR action, and by PRINN 2022 LSD (20228S5LWY). The authors would like also to thank the Centre for Electron Microscopies (Ce.ME) and the Centro di competenza RISE funded by FAS Regione Toscana.
KeyWords: Diagnostics; Mutations; Dynamics; Phase
DOI: 10.1038/s41598-024-76621-5