Identification of genetic modifiers of murine hepatic β-glucocerebrosidase activity

The acid beta-glucocerebrosidase (GCase) enzyme cleaves glucosylceramide into glucose and ceramide. Loss of function variants in the gene encoding for GCase can lead to Gaucher disease and Parkinson's disease. Therapeutic strategies aimed at increasing GCase activity by targeting a modulating factor are attractive and poorly explored. To identify genetic modifiers, we measured hepatic GCase activity in 27 inbred mouse strains. A genome-wide association study (GWAS) using GCase activity as a trait identified several candidate modifier genes, including Dmrtc2 and Arhgef1 (p=2.1x10(-7)), and Grik5 (p=2.1x10(-7)). Bayesian integration of the gene mapping with transcriptomics was used to build integrative networks. The analysis uncovered additional candidate GCase regulators, highlighting modules of the acute phase response (p=1.01x10(-8)), acute inflammatory response (p=1.01x10(-8)), fatty acid beta-oxidation (p=7.43x10(-5)), among others. Our study revealed previously unknown candidate modulators of GCase activity, which may facilitate the design of therapies for diseases with GCase dysfunction.

Automated summary

The study identified potential genetic modifiers of GCase activity by measuring hepatic GCase in inbred mouse strains and performing a GWAS. Candidate modifier genes such as Dmrtc2, Arhgef1, and Grik5 were found, and integrative networks were built using Bayesian integration of gene mapping and transcriptomics. Analysis revealed modules like acute phase response, acute inflammatory response, and fatty acid beta-oxidation as additional candidate GCase regulators.