Pluto Bioinformatics

GSE145524: Pex1-G844D NMRI mouse model of mild Zellweger spectrum disorder: liver gene expression profiles

Bulk RNA sequencing

Zellweger spectrum disorders (ZSD) are inborn metabolic diseases cause by genetic alterations in PEX genes leading to peroxisomal biogenesis disorder (PBD). Supportive care is standard since no validated treatment is able to modify the dismal natural history of the disease. Mouse models exist to study ZSD pathophysiology but they are limited by poor survival of the affected pups and breeding restrictions. To overcome these limitations, hypomorphic Pex1 p.G844D allele, equivalent to common mild human PEX1 p.G843D mutation, was backcrossed from C57BL/6N mouse to NMRI background. NMRI ZSD mouse breeding lead autosomal recessive Mendelian inheritance pattern with (median (min-max)) 10 (7-15) pups/mating compared to 4 (2-7) pups/mating in C57BL/6N background (p < 0.0001). We longitudinally phenotyped NMRI ZSD mice at 1, 2, 3 and 6 months of age to render this model suitable for future therapeutic interventions. NMRI ZSD mice exhibited growth retardation despite their higher daily energy intake. Mouse embryonic fibroblasts displayed classical PBD immunofluorescence pattern with peroxisomal mosaicism like milder ZSD patients skin fibroblasts. ZSD mice liver were enlarged and no liver lipid accumulation was detected. Yet, ZSD mouse plasma and liver showed very long-chain fatty acids, oxysterols and C27 bile acids intermediates elevation. Longitudinal study depicted trend to normalization for C26 and phytanic acid as it was shown for some ZSD patients reaching adulthood. ZSD mouse liver glycogen content was drastically reduced and liver RNA-Seq analysis confirmed glycogen metabolism genes downregulation. In conclusion, NMRI ZSD mouse model is suitable for ZSD liver-targeted therapies evaluation. SOURCE: Jérôme Ambroise (jambroise83@gmail.com) - Université catholique de Louvain