Genetic Variant in 3’ Untranslated Region of the MousePycardGene Regulates Inflammasome Activity

Quantitative trait locus mapping for interleukin-1β release after inflammasome priming and activation was performed on bone marrow-derived macrophages (BMDM) from an AKRxDBA/2 strain intercross. The strongest associated locus mapped very close to thePycardgene on chromosome 7, which codes for the inflammasome adaptor protein apoptosis-associated speck-like protein containing a CARD (ASC). The DBA/2 and AKRPycardgenes only differ at single nucleotide polymorphism (SNP) in their 3’ untranslated region (UTR). DBA/2 vs. AKR BMDM had increased levels ofPycardmRNA expression and ASC protein, and increased inflammasome speck formation, which was associated with increasedPycardmRNA stability without an increased transcription rate. CRIPSR/Cas9 gene editing was performed on DBA/2 embryonic stem cells to change thePycard3’UTR SNP from the DBA/2 to the AKR allele. This single base change significantly reducedPycardexpression and inflammasome activity after cells were differentiated into macrophages due to reducedPycardmRNA stability.