The STING inhibitor C-176 attenuates MPTP-induced neuroinflammation and neurodegeneration in mouse parkinsonian models

Recent emerging evidence reveals that cGAS-STING-mediated Type I interferon (IFN) signaling axis takes part in the microglial-associated neuroinflammation. However, the potential role of pharmacological inhibition of STING on neuroinflammation and dopaminergic neurodegeneration remains unknown. In the present study, we investigated whether pharmacological inhibition of STING attenuates neuroinflammation and neurodegeneration in experimental models of Parkinson's disease. We report that therapeutic inhibition of STING with C-176 significantly inhibited the activation of downstream signaling pathway, suppressed neuroinflammation, and ameliorated MPTP-induced dopaminergic neurotoxicity and motor deficit. Furthermore, pharmacological inhibition of STING with C-176 attenuated proinflammatory response in BV2 microglial cells exposed to LPS/MPP+. More importantly, C-176 also reduced NLRP3 inflammasome activation both in vitro and in vivo. The results of our study suggest that pharmacologic inhibition of STING protects against dopaminergic neurodegeneration and neuroinflammation that may act at least in part through suppressing NLRP3 inflammasome activation. STING signaling may hold great promise for the development of new treatment strategy for PD.