Pyruvate dehydrogenase kinase supports macrophage NLRP3 inflammasome activation during acute inflammation

Abstract

Activating macrophage NLRP3 inflammasome can promote excessive inflammation, with severe cell and tissue damage and organ dysfunction. Here, we show that pharmacological or genetic inhibition of pyruvate dehydrogenase kinase (PDHK) significantly attenuates NLRP3 inflammasome activation in murine and human macrophages and septic mice by lowering caspase-1 cleavage and IL-1{beta} secretion. Inhibiting PDHK reverses NLRP3 inflammasome-induced metabolic reprogramming, enhances autophagy, promotes mitochondrial fusion over fission, preserves cristae ultrastructure, and attenuates mitochondrial ROS production. The suppressive effect of PDHK inhibition on the NLRP3 inflammasome is independent of its canonical role as a pyruvate dehydrogenase regulator. We suggest that PDHK inhibition improves mitochondrial fitness by reversing NLRP3 inflammasome activation in acutely inflamed macrophages.