Dolutegravir Derivatives Alleviate LPS-Induced Microglial Inflammation by Suppressing STAT1/3 Nuclear Translocation.

Abstract

Purpose: Microglial inflammation plays a significant role in a variety of neurological disorders. Dolutegravir as a antiretroviral drug has been reported to inhibit the secretion of pro-inflammatory cytokines. Meanwhile, compounds containing 1,2,3-triazole have shown potential anti-inflammatory properties. Therefore, this study aims to investigate the anti-inflammatory potential of dolutegravir-1,2,3-triazole structural derivatives and elucidate its associated mechanisms of action.

Methods: Dolutegravir-1,2,3-triazole derivatives were synthesized through click chemistry reactions. The anti-inflammatory activity against microglial inflammation and cytotoxicity of these derivatives were evaluated using the Griess assay and MTT assay. In vitro, the effects of the compounds on the expression of inflammatory mediators in LPS-stimulated BV-2 microglial cells were assessed using Real-time PCR, ELISA, and Western blot. In vivo, the effects of the compounds on microglial inflammation and synaptic deficits in the hippocampus of LPS-challenged mice were evaluated using Real-time PCR, immunofluorescence, and Western blot.

Results: We discovered compound 4k exhibits the best inhibitory effect on microglial inflammation (IC₅₀ = 5.01 ± 0.57 μM) among the 27 dolutegravir derivatives. Compound 4k significantly attenuates the expression of LPS-induced microglial M1 phenotype markers, NO, IL-1β, IL-6, TNF-α, iNOS, and COX-2, while concurrently enhancing the expression of M2 phenotype markers, IL-4 and Ym-1. Further mechanistic exploration has elucidated that compound 4k modulates the polarization of microglia by suppressing the phosphorylation and nuclear translocation of STAT1/3 proteins. In the hippocampus of LPS-challenged mice, compound 4k markedly diminishes the expression of the microglial activation marker Iba1 and inflammatory mediators IL-1β, TNF-α, and COX-2 which led to an enhancement in the expression of the synaptic protein synaptophysin, thereby mitigating the synaptic defects.

Conclusion: Compound 4k exerts significant anti-microglial inflammatory effects by modulating the STAT signaling pathway to alleviate synaptic defects, which offers promising avenues for developing innovative anti-microglial inflammatory treatment strategies.