The HDAC3 inhibitor RGFP966 ameliorated ischemic brain damage by downregulating the AIM2 inflammasome

Authors
MJ Zhang, QC Zhao, MX Xia, J Chen, YT Chen, X Cao

Lab
Department of Neurology, the Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing City, Jiangsu Province, P. R. China.

Journal
The FASEB Journal

Abstract
Histone deacetylases 3 (HDAC3) modulates the acetylation state of histone and non-histone proteins and could be a powerful regulator of the inflammatory process in stroke. Inflammasome activation is a ubiquitous but poorly understood consequence of acute ischemic stroke. Here, we investigated the potential contributions of HDAC3 to inflammasome activation in primary cultured microglia and experimental stroke models. In this study, we documented that HDAC3 expression was increased in mi-croglia of mouse experimental stroke model. Intraperitoneal injection of RGFP966 (a selective inhibitor of HDAC3) decreased infarct size and alleviated neurologi-cal deficits after the onset of middle cerebral artery occlusion (MCAO). In vitro data indicated that LPS stimulation evoked a time-dependent increase of HDAC3 and absent in melanoma 2 (AIM2) inflammasome in primary cultured microglia. Interestingly, AIM2 was subjected to spatiotemporal regulation by RGFP966. The ability of RGFP966 to inhibit the AIM2 inflammasome was confirmed in an ex-perimental mouse model of stroke. As expected, AIM2 knockout mice also demonstrated significant resistance to ischemia injury compared with their wild-type littermates. RGFP966 failed to exhibit extra protective effects in AIM2_/_ stroke mice. Furthermore, we found that RGFP966 enhanced STAT1 acetylation and subsequently attenuated STAT1 phosphorylation, which may at least partially contributed to the negative regulation of AIM2 by RGFP966. Together, we initially found that RGFP966 alleviated the inflammatory response and protected against ischemic stroke by regulating the AIM2 inflammasome.

BIOSEB Instruments Used:
Grip strength test (BIO-GS3)