Study of Methionine Choline Deficient Diet-Induced Steatosis in Mice Using Endogenous Fluorescence Spectroscopy

Area of Science:

• Biomedical Optics
• Hepatology
• Medical Diagnostics

Background:

• Non-alcoholic fatty liver disease (NAFLD) is a global health concern, increasing risks for liver fibrosis, cirrhosis, and cancer.
• Accurate diagnosis and staging of hepatic steatosis are crucial for patient management and treatment strategies.
• Current diagnostic methods, including liver biopsy, have limitations, necessitating the development of novel, non-invasive tools.

Purpose of the Study:

• To evaluate the potential of fluorescence spectroscopy as a diagnostic tool for assessing hepatic steatosis progression in NAFLD.
• To develop and validate a spectroscopic method for differentiating mild and advanced stages of steatosis.
• To identify optimal excitation wavelengths for accurate steatosis classification.

Main Methods:

• Ex-vivo mouse liver samples were analyzed after 2 or 8 weeks on a methionine-choline deficient diet.
• Hepatic steatosis was histologically evaluated and quantified using Oil-Red O staining.
• Fluorescence spectroscopy was employed with excitation at 330, 365, 385, 405, and 415 nm, coupled with multivariate statistical analysis (PCA and QDA).

Main Results:

• Endogenous fluorescence intensity increased with diet duration, indicating steatosis progression.
• Spectroscopic analysis successfully discriminated control livers from steatotic livers and differentiated diet exposure times.
• Excitation at 405 nm provided the best classification performance, achieving >98.6% sensitivity and >99.3% specificity with 1.5% total classification error.

Conclusions:

• Fluorescence spectroscopy is a promising, highly accurate method for non-invasively assessing NAFLD and steatosis progression.
• The 405 nm excitation wavelength offers optimal performance for distinguishing between different stages of hepatic steatosis.
• This technique could serve as a valuable adjunct to liver biopsy for improved NAFLD diagnosis and monitoring.