Does decreased taurine and creatine in the thalamus by magnetic resounances spectroscopy (MRS) relate to neurological disorders in mice with late stage ALD?

Objectives Objectives: These studies are designed to quantify in vivo functional changes of neurobiochemicals in the thalamus in mice with late stage alcoholic liver diseases (ALD), to study neurological disorders including behavioral and brain and liver histopathological changes, and to seek correlations between behavior disorders and neurobiochemical changes within the thalamus.

Methods Methods: 6-8 week old BALB/C mice were fed with Lieber-DeCarli diets containing 27% calories as ethanol or control diets for 7 months. The research protocol was approved by IACUC of the UMSOM. After 7 months of feeding, In vivo MRS quantification in the thalamus was acquired using Bruker BioSpec 7T MR scanner. These animals subsequently underwent open field test (OFT) by our established standard methods. When all tests were completed, the tissues of livers and brains as well as blood samples were collected for pathological analyses including liver and brain H&E staining for pathological changes, terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL) staining for neuron apoptosis, and glial fibrillary acidic protein (GFAP) staining for astrocytosis. Data were analyzed by Two-Way ANOVA.

Results Results: Firstly, in vivo MRS thalamus quantification revealed in late stage ALD mice, significantly decreased levels (mM) of creatine (5.74 ± 0.23 vs. 6.75 ± 0.16, p< 0.001) and taurine (4.22 ± 0.30 vs. 5.34 ± 0.19, p<0.001) which may relate to oxidative stress pathogenesis. There were significantly increased levels of glutamine (2.68 ± 0.13 vs. 2.17 ± 0.11, p<0.05) which may indicate neurotoxicity. Secondly, we performed OFT using the same animals. OPT results demonstrated decreased times of central travel entries at the first 10 min (4.9 ± 1.3 vs. 15.6 ± 4.3, p<0.001), central travel distance in centimeters (20 ± 8.9 vs. 81 ± 16, p<0.001) and travel spending times in seconds (4.7±1.4 vs. 14.7 ± 3.9, p<0.001). Late stage ALD mice also demonstrated decreased peripheral travel distance in centimeters at first 10 min (100.3 ± 10.3 vs. 207.9 ± 19.6, p<0.001) and travel spending times in seconds at the first 10 min ( 157.2± 21.4 vs. 356.7 ± 61.1, p< 0.001) in peripheral regions. Then, we found a significant correlation of taurine and creatine to both central and peripheral results of the OFT, indicating oxidative stress may play an important role in underlying neurological dysfunction. Lastly, pathological analyses showed diffuse fat deposits, inflammatory cellular infiltration and significant fibrosis formation throughout the livers in ethanol fed animals. Blood liver functional tests showed increased ALT and AST levels in late stage ALD mice. Blood LPS levels were also elevated. Brain pathological analysis showed significantly increased changes of neuron degeneration by H&E staining, apoptosis by TUNEL and astrocytosis by GFAP staining in late stage ALD mice.

Conclusions Conclusions: Our MRS thalamus neurobiochemical profile quantification studies for the first time has revealed strong correlations between oxidative stress-related neurobiochemicals taurine and creatine in thalamus and neurological disorders via increased neuron degeneration, apoptosis and astrocytosis in the same region in late stage ALD model. Thus, MRS non-invasive functional study is an important method to study ALD related neurological disorders. Funded by Department Chair Research Fund, RSNA Resident Research Grant, and Innovation Seed Grant of UMB and UMCP.