Knockout of MAPK Phosphatase-1 Exaggerates Type I IFN Response during Systemic Escherichia coli Infection

Abstract

We have previously shown that Mkp-1deficient mice produce elevated TNF-a, IL-6, and IL-10 following systemic Escherichia coli infection, and they exhibited increased mortality, elevated bacterial burden, and profound metabolic alterations. To understand the function of Mkp-1 during bacterial infection, we performed RNA-sequencing analysis to compare the global gene expression between E. coliinfected wild-type and Mkp-1 2/2 mice. A large number of IFN-stimulated genes were more robustly expressed in E. coliinfected Mkp-1 2/2 mice than in wild-type mice. Multiplex analysis of the serum cytokine levels revealed profound increases in IFN-b, IFN-g, TNF-a, IL-1a and b, IL-6, IL-10, IL-17A, IL-27, and GMSF levels in E. coliinfected Mkp-1 2/2 mice relative to wildtype mice. Administration of a neutralizing Ab against the receptor for type I IFN to Mkp-1 2/2 mice prior to E. coli infection augmented mortality and disease severity. Mkp-1 2/2 bone marrowderived macrophages (BMDM) produced higher levels of IFN-b mRNA and protein than did wild-type BMDM upon treatment with LPS, E. coli, polyinosinic:polycytidylic acid, and herring sperm DNA. Augmented IFN-b induction in Mkp-1 2/2 BMDM was blocked by a p38 inhibitor but not by an JNK inhibitor. Enhanced Mkp-1 expression abolished IFN-b induction by both LPS and E. coli but had little effect on the IFN-b promoter activity in LPSstimulated RAW264.7 cells. Mkp-1 deficiency did not have an overt effect on IRF3/7 phosphorylation or IKK activation but modestly enhanced IFN-b mRNA stability in LPS-stimulated BMDM. Our results suggest that Mkp-1 regulates IFN-b production primarily through a p38-mediated mechanism and that IFN-b plays a beneficial role in E. coliinduced sepsis.

p38 MAPK and MKP-1 control the glycolytic program via the bifunctional glycolysis regulator PFKFB3 during sepsis

“…Increased mRNA stability often contributes to the enhanced expression of inflammatory genes, such as genes of inflammatory cytokines, during pathogen and TLR ligand stimulation ( 36 , 37 ). MKP-1 is known to regulate the mRNA stability of numerous inflammatory genes ( 38 , 39 , 40 ). We investigated whether Mkp-1 deficiency alters the half-life of Pfkfb3 mRNA in macrophages stimulated by LPS.…”

“…However, following LPS stimulation, WT and Mkp-1 −/− BMDM had similar HIF1α levels (data not shown). We have previously shown that Mkp-1 deficiency does not have an obvious effect on NF-κB pathway activation in LPS-stimulated BMDM ( 40 ). Thus, enhanced Pfkfb3 expression in Mkp-1 −/− macrophages following LPS and E. coli stimulation is probably mediated via a p38 MAPK-regulated transcriptional factor(s), rather than NF-κB or HIF1α.…”

“…Tissues were homogenized to extract proteins for Western blot analysis. Total RNA was isolated from four animals in each treatment group for RNA-seq analysis ( 27 , 40 , 49 ). The RNA-seq data have been deposited in Gene Expression Omnibus (GSE122741).…”

“…BMDMs were generated from WT and Mkp-1 KO mice on the C57BL/6J background as previously described ( 40 ) and were stimulated with LPS (O55:B5, Calbiochem) or heat-killed E. coli for different times. In some experiments, BMDM were pretreated with vehicle (DMSO), a p38 MAPK inhibitor (SB203580 ( 63 ), Calbiochem), a JNK inhibitor (JNK-IN-8 ( 64 ), Selleck Chemicals), or a combination of both inhibitors for 15 min prior to LPS stimulation.…”

ING4 Promotes Stemness Enrichment of Human Renal Cell Carcinoma Cells Through Inhibiting DUSP4 Expression to Activate the p38 MAPK/type I IFN-Stimulated Gene Signaling Pathway

“…The activation of MAPK has been reported to play an important role in type I IFN signaling pathway for CSCs formation ( Patel et al, 2016 ; Fang et al, 2017 ; Lu et al, 2018 ; Kirk et al, 2021 ), and ING4 can regulate the Erk1/2 and p38 MAPK activity ( Zhang et al, 2007 ). We examined the activation status of Erk1/2 and p38 MAPK in ING4-overexpressed or knockdown Ketr-3 and 786-O cells and found that the phosphorylation level of p38 MAPK was significantly increased in the ING4 overexpression group and decreased in the sg-ING4-2 and sg-ING4-3 groups compared to the respective control groups.…”