TMAO promotes NLRP3 inflammasome activation of microglia aggravating neurological injury in stroke through FTO/IGF2BP2

Stroke is a kind of cerebrovascular disease with high mortality. TMAO has been shown to aggravate stroke outcomes, but its mechanism remains unclear. Mice were treated with TMAO in normal saline by oral gavage for 14 consecutive days. Then, mice were made into MCAO models. Neurological score, infarct volume, neuronal damage and markers associated with inflammation were assessed. Since microglia played a crucial role in stroke, microglia of MCAO mice were isolated for high-throughput sequencing to identify the most differentially expressed gene following TMAO treatment. Afterward, the downstream pathways of TMAO were investigated using primary microglia. Our results demonstrated that TMAO promoted the release of inflammatory cytokines in the brain of MCAO mice and promoted the activation of OGD/R microglial inflammasome, thereby exacerbating stroke outcomes. FTO/IGF2BP2 inhibited NLRP3 inflammasome activation in OGD/R microglia by downregulating the m6A level of NLRP3, TMAO can inhibit the expression of FTO and IGF2BP2, thus promoting the activation of NLRP3 inflammasome in OGD/R microglia. In conclusion, these results demonstrated that TMAO promotes NLRP3 inflammasome activation of microglia aggravating neurological injury in stroke through FTO/IGF2BP2. Overall design: Microglial mRNA profiles of 6 months old C57BL/6J mice were treated with TAMO