Artesunate interacts with Vitamin D receptor to reverse mouse model of sepsis-induced immunosuppression via enhancing autophagy

Background and Purpose Immunosuppression is the predominant cause of mortality for sepsis due to failure to eradicate invading pathogens. Unfortunately, no effective and specific drugs capable of reversing immunosuppression are available for clinical use. Increasing evidence implicates vitamin D receptor (VDR) involved in sepsis-induced immunosuppression. Herein, artesunate (AS) was discovered to reverse sepsis-induced immunosuppression and its molecular mechanism is investigated. Experimental Approach Effect of artesunate on sepsis-induced immunosuppression was investigated in mice and in vitro . VDR was predicted to be an interacted candidate of AS by bioinformatics predict, then identified using PCR and immunoblotting. VDR, ATG16L1 and NF-κB p65 were modified to investigate the alteration of AS’s effect on pro-inflammatory cytokines release, bacteria clearance and autophagy activities in sepsis-induced immunosuppression. Key Results AS significantly reduced the mortality of cecal ligation and puncture (CLP)-induced sepsis immunosuppression mice challenged with Pseudomonas Aeruginosa , and enhanced proinflammatory cytokines release and bacterial clearance to reverse sepsis-induced immunosuppression in vivo and in vitro . Mechanically, AS interacted with VDR thereby inhibited the nuclear translocation of VDR, then influencing ATG16L1 transcription and subsequent autophagy activity. In addition, AS inhibited physical interaction between VDR and NF-κB p65 in LPS tolerance macrophages, then promoted nuclear translocation of NF-κB p65, which activated the transcription of NF-κB p65 target genes such as pro-inflammatory cytokines. Conclusion and Implications Our findings provide an evidence that AS interacted with VDR to reverse sepsis-induced immunosuppression in an autophagy and NF-κB dependent way, highlighting a novel approach for sepsis treatment and drug repurposing of AS in the future.