M. Schade1, J. Sanabria1, R. Aguilar1, M. Andryka1, A. Mallick1, J. Fannin1, J. Sanabria1,2 1Marshall University Schoool Of Medicine,Department Of Surgery,Huntington, WV, USA 2Case Western Reserve University School Of Medicine,Surgery, Nutrition And Preventive Medicine,Cleveland, OH, USA
Introduction:
Non Alcoholic Liver Disease (NAFLD) and its complications, NASH, ESLD and HCC have become the second most common cause for liver transplantation in the West. Although major advances have been done in the understanding of fatty liver disease, the metabolic disturbances that occur in the normal cell from NAFLD to NASH remains to be determined.
Methods:
C57Bl 6J mice (female: n=7/male: n=7 per each time point) were exposed to normal chow (control), high fat diet + fructose (HFD, Western diet) and methyl choline deficient diet (MCD). Liver and plasma were collected at weeks 7, 12, 16, 20, 24 and 48. Body weight, total body water, lean mass and fat compartment were determined by MRI spectroscopy. The proportion of cells undergoing mitosis or cell arrest were determined against liver apoptotic index and collagen deposition by standard stains using morphometric techniques. Quantitative protein expression of genes involved in cell metabolism or cell senescence (p53, p21, p16, mTOR1, STAT33, SIRT7, FOX01, Grb2) were determined by Western Blots. In addition, Na/K-exchange pump regulation was determined by SRC expression. While liver oxidative stress was determined by glutathione sp, hepatic mitochondrial ß -lipid oxidation function was determined by octanoate/butyrate ratio. Metabolites (n=852) were measured in treated plasma by LC/MS-MS. Principal component analyses (PCA) was conducted to detect metabolite differences among groups.
Results:
The total body weight corrected for aging increased significantly in the HFD due to an increase in the fat compartment with similar lean mass and total body water (HFD vs normal chaw, p<005 by ANOVA). The animals in the MCD group had a significant decrease in their body weight due to decreased fat, lean and total body water (MCD vs normal chaw, p<005 by ANOVA). Nonetheless, both diets induced NAFL/NASH. An increased proportion of cells in senescence was observed with decreased mitotic index and increased apoptotic activity (HFD and MCD vs normal chaw, p<0.05 by ANOVA). Morphological changes correlated with gene expression. Significant decreased in both mitochondrial ß-lipid oxidation function and Na/K-exchange pump activity after censored for aging (HFD and MCD vs normal chaw, p<0.05, by ANOVA). Glutathione ratio reduced/oxidized was significantly reduced animals with fatty liver (HFD and MCD vs normal chaw, p<0.05, ANOVA). Metabolic signatures of NAFLD and NASH after censored for aging on cell aging demonstrated disturbances in the lipid and carbohydrate metabolism.
Conclusion:
HFD and MCD generates NAFLD/NASH with decreased cellular redox status and mitochondrial ß-lipid oxidation, manifested by metabolic changes that are seen in accelerated cell senescence with characteristic plasma metabolic signatures. Described metabolic changes are of interest as therapeutic targets for arrest or reversibility of disease progression.