Chrysomycin A Attenuates Neuroinflammation by Down-Regulating NLRP3/Cleaved Caspase-1 Signaling Pathway in LPS-Stimulated Mice and BV2 Cells.

Man Liu,Ying-Lin Yang,Shan-Shan Zhang,Yue-Hua Wang,Dong-Ni Liu,Guan-Hua Du

doi:10.3390/ijms22136799

Abstract

Chrysomycin A (Chr-A), an antibiotic chrysomycin, was discovered in 1955 and is used to treat cancer and tuberculosis. In the present study, the anti-neuroinflammatory effects and possible mechanism of Chr-A in BALB/c mice and in BV2 microglia cells stimulated by lipopolysaccharide (LPS) were investigated. Firstly, the cortex tissues of mice were analyzed by RNA-seq transcriptome to identify differentially expressed genes (DEGs) regulated by Chr-A in LPS-stimulated mice. Inflammatory cytokines and inflammatory proteins were detected by enzyme-linked immunosorbent assay and Western blot. In RNAseq detection, 639 differential up-regulated genes between the control group and LPS model group and 113 differential down-regulated genes between the LPS model group and Chr-A treatment group were found, and 70 overlapping genes were identified as key genes for Chr-A against neuroinflammation. Subsequent GO biological process enrichment analysis showed that the anti-neuroinflammatory effect of Chr-A might be related to the response to cytokine, cellular response to cytokine stimulus, and regulation of immune system process. The significant signaling pathways of KEGG enrichment analysis were mainly involved in TNF signaling pathway, cytokine–cytokine receptor interaction, NF-κB signaling pathway, IL-17 signaling pathway and NOD-like receptor signaling pathway. Our results of in vivo or in vitro experiments showed that the levels of pro-inflammatory factors including NO, IL-6, IL-1β, IL-17, TNF-α, MCP-1, CXCL12, GM-CSF and COX2 in the LPS-stimulated group were higher than those in the control group, while Chr-A reversed those conditions. Furthermore, the Western blot analysis showed that its anti-neuroinflammation appeared to be related to the down-regulation of NLRP3/cleaved caspase-1 signaling pathway. The current findings provide new insights into the activity and molecular mechanisms of Chr-A for the treatment of neuroinflammation.

Highlights

Neuroinflammation has been regarded as having a potential role in the progression or etiology of various central nervous system (CNS) diseases, including cerebral ischemiareperfusion injury, Alzheimer’s disease (AD) and Parkinson’s disease (PD) [1,2,3]
In order to reveal the crucial targets for protective effect of Chrysomycin A (Chr‐A) for treatment of LPS-stimulatedneuroinflammation, neuroinflammation, RNA
We found that LPS induced the release of pro-inflammatory cytokines, such as IL-1β, IL-6, IL-17 and TNF-α; chemokines, such as MCP-1 and CXCL12; and colony-stimulating factor, such as GM-cerebrospinal fluid (CSF) in the cortex of LPS-induced mice

Summary

Introduction

Neuroinflammation has been regarded as having a potential role in the progression or etiology of various central nervous system (CNS) diseases, including cerebral ischemiareperfusion injury, Alzheimer’s disease (AD) and Parkinson’s disease (PD) [1,2,3]. As the central effectors of neuroinflammation, provide structural and metabolic support in the brain and participate in clearing cellular debris through phagocytosis [4]. Microglia express numerous pattern recognition receptors and can be activated by LPS, a vital molecular component of the cell outer membrane of Gram-negative bacteria, via upregulating Toll-like receptors (TLRs) and NOD-like receptors (NLRs) signaling pathways, followed by the production and release of pro-inflammatory cytokines [5,6].

Results

Discussion

Conclusion