Glutaminase regulates extracellular vesicles release through key metabolic intermediate α-ketoglutarate in HIV-1-infected macrophages

Abstract

Extracellular vesicles (EVs) are important in the intercellular communication in the CNS and their release is increased upon neuroinflammation. Our previous data demonstrated the increased release of EVs induces neurotoxicity during HIV-1 infection. However, the molecular mechanism by which HIV-1 increases EV release remains unknown. In current study, we investigated glutaminase (GLS), a mitochondria enzyme critical for glutamine metabolism, in EV release. We used transmission electron microscopy, NanoSight and Western blot to quantify and confirm the elevation of EV release in HIV-1-infected macrophages. Interestingly, overexpression of GLS led to increased release of EVs. Blocking the GLS activity by GLS inhibitors significantly reduced EV release, suggesting a critical role of GLS in EV release. Furthermore, the inhibited EV release was reversed by the addition of α-ketoglutarate, identifying it as a critical downstream effector for GLS inhibitors. Consistently, the EV levels were significantly higher in GLS-transgenic mice than control mice, suggesting that GLS increases EV release in vivo. In conclusion, these findings support GLS as an essential enzyme that regulates EV release through key metabolic intermediate α-ketoglutarate during HIV-1 infection. Therefore, GLS inhibitors may serve as novel therapeutic agents to block the adverse effect of EVs during HIV-1 neurological complications.