B012 Phenotypic studies on neurodegeneration in the Huntington’s disease knock-in minipig model

<h3>Background</h3> Recent promising treatments for Huntington’s disease (HD) require preclinical testing in large animals. We generate, breed, and monitor the phenotype of HD minipig models to aid in the development of potential therapies for Huntington’s disease. <h3>Aims</h3> This study aimed to track brain phenotype development in a new knock-in (KI-85Q-HD) minipig model of Huntington’s disease. <h3>Methods</h3> Phenotype development in the KI-85Q-HD minipig model was monitored using biochemical and histological analysis of brain tissue. Histological analysis was performed on animals aged 24 months and 36 months. Transcriptome analysis was conducted using RNA sequencing. MRI scans were performed on 5 KI-85Q-HD and 5 wild-type (WT) pigs at 3.5 and 5.5 years of age. <h3>Results</h3> Brain tissue analysis revealed increased levels of soluble mutant HTT and signs of demyelination at 36 months. RNA sequencing showed differential gene expression, with higher number of differentially expressed genes expression levels in the cortex compared to the putamen. Small pool PCR indicated somatic CAG expansion in liver and brain samples. 3’ RACE amplification identified a short mRNA (exon 1 intron 1), suggesting aberrant splicing. MRI scans revealed subcortical atrophy in some KI-85Q-HD pigs. <h3>Conclusions</h3> The KI-85Q-HD minipig model exhibits a mild, age-dependent phenotype, making it a valuable model for studying Huntington’s disease and testing potential therapies. <h3>Support</h3> CHDI Foundation, Czech Academy of Sciences - Strategy AV21 (VP29), Johannes Amos Comenius Programme (Research Excellence in Regenerative medicine, CZ.02.01.01/00/22_008/0004562).