BACKGROUND AND PURPOSELipopolysaccharides (LPS) and oligodeoxynucleotides containing CpG motifs (CpG DNA) are important pathogenic molecules for the induction of sepsis, and thus are drug targets for sepsis treatment. The present drugs for treating sepsis act only against either LPS or CpG DNA. Hence, they are not particularly efficient at combating sepsis as the latter two molecules usually cooperate during sepsis. In this study, a natural alkaloid compound kukoamine B (KB) is presented as a potent dual inhibitor for both LPS and CpG DNA. EXPERIMENTAL APPROACHThe affinities of KB for LPS and CpG DNA were assessed using biosensor technology. Direct interaction of KB with LPS and CpG DNA were evaluated using neutralization assays. Selective inhibitory activities of KB on pro-inflammatory signal transduction and cytokine expression induced by LPS and CpG DNA were analysed by cellular assays. Protective effects of KB in a sepsis model in mice were elucidated by determining survival and circulatory LPS and tumour necrosis factor-alpha (TNF-a) concentrations. KEY RESULTSKB had high affinities for LPS and CpG DNA. It neutralized LPS and CpG DNA and prevented them from interacting with mouse macrophages. KB selectively inhibited LPS-and CpG DNA-induced signal transduction and expression of pro-inflammatory mediators without interfering with signal pathways or cell viability in macrophages. KB protected mice challenged with heat-killed Escherichia coli, and reduced the circulatory levels of LPS and TNF-a. CONCLUSIONS AND IMPLICATIONSThis is the first report of a novel dual inhibitor of LPS and CpG DNA. KB is worthy of further investigation as a potential candidate to treat sepsis. Abbreviations

No abstract

Lipopolysaccharide (LPS) is a key pathogenic factor in sepsis, and its recognition by toll-like receptor 4 (TLR4) can activate two district signaling pathways, leading to activation of transcription factors including NF-κB and interferon regulatory factor 3 (IRF3). Chloroquine (CQ) has been shown to affect LPS-TLR4 colocalization and inhibit both MyD88-dependent and TRAM/TRIF-dependent pathways, though the mechanism involved is still poorly understood. Here, we found that the ubiquitin-proteasome system might be involved in this process. CQ increased USP25, a deubiquitinating enzyme, as well as mRNA and protein expression in a dose-dependent manner, which might to some degree be involved in CQ attenuation of LPS-induced macrophage activation. Overexpression of USP25 decreased LPS-induced inflammatory cytokines like TNF-α, IL-6, and IFN-β, while specific siRNA-mediated USP25 silencing increased TNF-α, IL-6, and IFN-β production and secretion. In addition, USP25 deletion strengthened mitogen-activated protein kinase (MAPKs) phosphorylation and IκB degradation. Moreover, USP25 interference increased NF-κB and IRF3 nuclear translocation. Taken together, our data demonstrated a new possible regulator of LPS-induced macrophage activation mediated by CQ, through upregulation of USP25.

Introduction: Botulinum Toxin Type A (BoNT/A) is a bacterial toxin commonly used in cosmetic therapy. Although there has been a great deal of clinical and basic research on the potential therapeutic applications of botulinum toxin there are few reports on its clinical toxicity and side effects. Patient Concerns: A previously healthy 26-year-old woman developed joint pain and redness in her right toe, swelling in the posterior left foot and the interphalangeal joint of the right index finger, occasional shoulder pain, and morning stiffness for 30 minutes daily, 6 months after BoNT/A injection. Diagnosis: Laboratory testing showed elevated Rheumatoid Factor (RF), anti-cyclic citrullinated peptide (anti-CCP), C-Reactive Protein (CRP), Erythrocyte Sedimentation Rate (ESR). Doppler ultrasound examination of the right hand and both feet showed synovial hyperplasia of the right wrist, right second proximal interphalangeal joint, both ankles, and right first metatarsophalangeal joint, as well as bony erosion in a left intertarsal joint. Magnetic Resonance (MR) examination for right hand showed multiple joint changes of right hand and wrist, which included synovium thickening and enhancement. She was diagnosed as rheumatoid arthritis. Interventions: BoNT/A injection was stopped. Methotrexate 10mg was given once weekly and hydroxychloroquine 0.2g was given twice daily with subsequent remission of arthritis. Outcomes: At 12 months from diagnosis, patient reported complete joints remission. Conclusions: This is the first report of rheumatoid arthritis caused by botulinum toxin injection, and we speculate on the mechanism of its occurrence in this paper. In addition, we systematically introduce the latest research results on the development mechanism of BoNT/A causing RA. This review suggests that it is necessary to further explore the specific mechanism of RA or osteochondral injury caused by BoNT/A, which will not only help to improve the current understanding of the potential toxic and side effects of BoNT/A in clinical application, but also promote the standardization of clinical application of BoNT/A.