Integrative behavioral, histological, and proteomics profiling identifies cerebellar drivers of motor dysfunction in...

Hepatic encephalopathy (HE) is a neuropsychiatric disease caused by liver failure and/or portosystemic shunting and is characterized by cognitive and motor impairments. Although it is typically thought to be reversible after liver transplantation, recent research suggests the opposite. This underscores the need for a deeper understanding of HE pathophysiology. Both motor and cognitive function impairments are characteristic of HE and these two functions are controlled by the cerebellum. Therefore, we performed behavioral and histological studies to investigate motor dysfunction and neurodegeneration in thioacetamide-induced moderate-grade hepatic encephalopathy (MoHE) rats. To further investigate the molecular changes in the cerebellum, we utilized label-free-based mass spectrometry analysis. Rotarod and gait tests indicated gross and fine motor impairment, respectively. Histological examination revealed Purkinje neuron degeneration and Bergmann glial fiber hypertrophy. Mass spectrometry analysis identified 2,002 proteins, of which 65 were significantly differentially expressed (35 upregulated and 30 downregulated). Bioinformatic analysis of these 65 proteins revealed dysregulation of calcium ion signalling, GTPase cycles, endocytosis, and apoptosis. Western blotting showed the upregulation of RheB, MPPCB, and fetuin-A, which further validated the MS results. Immunofluorescence also validated the overexpression of these proteins, along with lactadherin, and showed spatial distribution in the granular and Purkinje layers of the cerebellum. This study provides a profile of proteomic changes in the cerebellum and the associated dysregulated biological pathways that may be responsible for the pathophysiology. These findings not only highlight promising new therapeutic targets but also open the door to the development of innovative treatments that could significantly improve patient outcomes.