Histone deacetylase 6 negatively regulates NLRP3 inflammasome activation

Abstract

Emerging reports demonstrate that deregulated NLRP3 inflammasome activation is implicated in a variety of inflammatory and metabolic disorders, but the molecular mechanism underlying NLRP3 inflammasome regulation remains uncertain. Here, we present evidence that histone deacetylase 6 (HDAC6) inhibits the activation of NLRP3 inflammasome through its direct association with NLRP3. ShRNA-mediated knockdown of HDAC6 in bone marrow-derived macrophages (BMDMs) showed a significant increase in caspase-1 activation and interleukin-1 beta (IL-1β) secretion in response to NLRP3-activating stimulations, but not to absent in melanoma 2 (AIM2)-activating stimulation. In addition, knockdown of HDAC6 in BMDMs enhanced the oligomerization of ASC upon LPS/nigericin stimulation. The augmented NLRP3 inflammasome activation seen in HDAC6-knockdown BMDMs is independent of the deacetylase activity of HDAC6. Instead, HDAC6 directly associates with NLRP3 through its ubiquitin-binding domain. Moreover, PR619 treatment (deubiquitinase inhibitor) resulted in the elevation in the interaction of NLRP3 with HDAC6 and the decrease in NLRP3-dependent caspase-1 activation. Taken together, our results indicate that HDAC6 negatively regulates NLRP3 inflammasome activation through its interaction to ubiquitinated NLRP3.

Keywords: Histone deacetylase 6; Inflammasome; NLRP3.