In the autoimmune disease rheumatoid arthritis (RA), CD4+ Tcells promote pro-inflammatory effector functions by shunting glucose away from glycolysis and ATP production. Underlying mechanisms remain unknown, and here we implicate the DNA repair nuclease MRE11A in the cells' bioenergetic failure. MRE11A deficiency in RA Tcells disrupted mitochondrial oxygen consumption and suppressed ATP generation. Also, MRE11A loss of function caused leakage of mitochondrial DNA (mtDNA) into the cytosol, triggering inflammasome assembly, caspase-1 activation, and pyroptotic cell death. Caspase-1 activation was frequent in lymph-node-residing Tcells in RA patients. Invivo, pharmacologic and genetic inhibition of MRE11A resulted in tissuedeposition of mtDNA, caspase-1 proteolysis, andaggressive tissue inflammation. Conversely, MRE11A overexpression restored mitochondrial fitness and shielded tissue from inflammatory attack. Thus, the nuclease MRE11A regulates a mitochondrial protection program, and MRE11A deficiency leads to DNA repair defects, energy production, and failure and loss of tissue homeostasis.
View details for DOI 10.1016/j.cmet.2019.06.016
View details for PubMedID 31327667