Spi1 and Usp7 aggravate diabetic encephalopathy through regulating Ddx3x

DEAD-box helicase 3 X-linked (DDX3X) can interact with NOD-like receptor protein 3 (NLRP3) to drive inflammasome activation. Nonetheless, the role of DDX3X on NLRP3 inflammasome activation in diabetic encephalopathy remains unidentified. Here, Ddx3x knockdown alleviates microglial NLRP3 activation, which reverses the increased permeability and decreased tight junction proteins induced by conditioned medium of lipopolysaccharide-stimulated microglia (LPS-CM) in bEnd.3 endothelial cells, and overturns LPS-CM-elicited apoptosis promotion in HT22 neurons. In male type 2 diabetes db/db mice, Ddx3x silencing mitigates microglial activation, blood-brain barrier disruption, neuronal apoptosis and cognitive impairment. Spi-1 proto-oncogene (SPI1) transcriptionally activates Ddx3x ; Additionally, ubiquitin-specific protease (USP)7 reduces DDX3X ubiquitination to increase its protein stability. Silencing Spi1 / Usp7 exerts beneficial effects in vitro and in vivo, which are neutralized when overexpressing Ddx3x . In conclusion, Spi1 / Usp7 knockdown downregulates DDX3X to inhibit microglial NLRP3 activation, alleviating BBB dysfunction and neuronal loss to ameliorate diabetic encephalopathy, which suggests prospective targets for diabetic encephalopathy.