Ablation of dual specificity phosphatase 6 protects against non-alcoholic fatty liver disease via CYP4A and MAPK
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PROVIDER: PRJNA896103 | ENA |
REPOSITORIES: ENA
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Project description:Dual specificity phosphatase 6 (DUSP6) is a specific phosphatase for mitogen-activated protein kinase (MAPK). In this study, we used a high-fat diet (HFD)-induced murine non-alcoholic fatty liver disease (NAFLD) model to investigate the role of DUSP6 in this disease. Wild-type (WT) and Dusp6-haploinsufficient (HI) mice developed severe obesity and liver pathology consistent with NAFLD when exposed to HFD. In contrast, Dusp6-knockout (KO) mice completely eliminated these phenotypes. Furthermore, primary hepatocytes isolated from WT mice exposed to palmitic and oleic acids exhibited abundant intracellular lipid accumulation, while hepatocytes from Dusp6-KO mice showed minimal lipid accumulation. Transcriptome analysis revealed significant downregulation of genes encoding cytochrome P450 4A (CYP4A), known to promote ω-hydroxylation of fatty acids and hepatic steatosis, in Dusp6-KO hepatocytes compared with WT hepatocytes. Diminished CYP4A expression was observed in the liver of Dusp6-KO mice compared to WT and Dusp6-HI mice. Knockdown of DUSP6 in HepG2, a human liver-lineage cell line, also promoted a reduction of lipid accumulation, downregulation of CYP4A, and upregulation of phosphorylated/activated MAPK. Furthermore, inhibition of MAPK activity promoted lipid accumulation in DUSP6-knockdown HepG2 cells without affecting CYP4A expression, indicating that CYP4A expression is independent of MAPK activation. These findings highlight the significant role of DUSP6 in HFD-induced steatohepatitis through two distinct pathways involving CYP4A and MAPK.
2023-09-04 | GSE216881 | GEO
Project description:Mitogen-activated dual-specificity MAPK phosphatases are important negative regulators in the MAPK signalling pathways responsible for many essential processes in plants. In a screen for mutants with reduced organ size we have identified a mutation in the active site of the dual-specificity MAPK phosphatase INDOLE-3-BUTYRIC ACID-RESPONSE5 (IBR5) that we named tinkerbell (tink) due to its small size. Analysis of the tink mutant indicates that IBR5 acts as a novel regulator of organ size that changes the rate of growth in petals and leaves. Organ size and shape regulation by IBR5 acts independently of the KLU growth-regulatory pathway. Microarray analysis of tink/ibr5-6 mutants identified a likely role for this phosphatase in male gametophyte development. We show that IBR5 may influence the size and shape of petals through auxin and TCP growth regulatory pathways. 6 samples, three mutant replicates, three wild type replicates.
2015-07-30 | E-GEOD-66419 | biostudies-arrayexpress
Project description:Mitogen-activated dual-specificity MAPK phosphatases are important negative regulators in the MAPK signalling pathways responsible for many essential processes in plants. In a screen for mutants with reduced organ size we have identified a mutation in the active site of the dual-specificity MAPK phosphatase INDOLE-3-BUTYRIC ACID-RESPONSE5 (IBR5) that we named tinkerbell (tink) due to its small size. Analysis of the tink mutant indicates that IBR5 acts as a novel regulator of organ size that changes the rate of growth in petals and leaves. Organ size and shape regulation by IBR5 acts independently of the KLU growth-regulatory pathway. Microarray analysis of tink/ibr5-6 mutants identified a likely role for this phosphatase in male gametophyte development. We show that IBR5 may influence the size and shape of petals through auxin and TCP growth regulatory pathways.
2015-07-30 | GSE66419 | GEO
Project description:Mitogen-activated protein kinases are inactivated by dual specificity phosphatases (DUSPs), whose activities are tightly regulated during cell differentiation. Using knockdown screening and single-cell transcriptional analysis, we determined that DUSP4 is the phosphatase that specifically inactivates p38 kinase for the promotion of megakaryocyte (Mk) differentiation. Mechanistically, PRMT1-mediated methylation of DUSP4 triggers its ubiquitinylation by an E3 ligase HUWE1. Interestingly, the mechanistic axis of the DUSP4 degradation and p38 activation is also associated with a transcriptional signature of immune activation in Mk cells. In the context of thrombocytopenia observed in myelodysplastic syndromes (MDS), we demonstrated that high levels of p38 MAPK and PRMT1 are associated with low platelet counts and adverse prognosis, while pharmacological inhibition of p38 MAPK or PRMT1 stimulates megakaryopoiesis. These findings provide mechanistic insights into the role of the PRMT1-DUSP4-p38 axis on Mk differentiation and present a targeting strategy for treatment of thrombocytopenia associated with MDS.
2021-05-12 | GSE174261 | GEO
Project description:The mitogen-activated protein kinase (MAPK) p38 pathway is reported to regulate macrophage responses to lipopolysaccharide (LPS) at least partly via the phosphorylation of the mRNA-destabilizing factor tristetraprolin (TTP). LPS-activated MAPK p38 phosphorylates and activates the downstream kinase MAPK-activated protein kinase 2 (MK2), which then phosphorylates serines 52 and 178 of TTP, resulting in loss of mRNA-destabilizing activity. As a consequence, mRNAs that contain binding sites for TTP are stabilized in a manner that is acutely sensitive to the activity of the MAPK p38 pathway. Dual specificity phosphatase 1 (DUSP1) dephosphorylates and inactivates MAPK p38. Dusp1-/- macrophages overexpress a number of pro-inflammatory mediators, but their genome-wide responses to LPS have not yet been described in detail. Dusp1-/- mice are exceptionally sensitive to a wide variety of inflammatory challenges, including experimental models of endotoxemia or sepsis. It has been suggested (but not yet proven) that DUSP1 controls the inflammatory response of macrophages in part via the regulation of MAPK p38 activity and TTP phosphorylation status. We generated a mouse knock-in strain, in which codons 52 and 178 of the endogenous Zfp36 gene (which encodes TTP) were mutated to alanine codons. The mutation gives rise to a constitutively active form of TTP, which cannot be inactivated via the p38 MAPK pathway. The Zfp36aa/aa strain was back-crossed against C57/BL6 for > 10 generations. We also generated a double-targeted strain in which the Zfp36 mutation was combined with disruption of the Dusp1 gene. This expression array describes LPS responses of primary mouse bone marrow-derived macrophages of four genotypes, and closely matched genetic background: wild type (Dusp1+/+ : Zfp36+/+); TTP mutant (Zfp36aa/aa); DUSP1 knock out (Dusp1-/-); and double targeted (Dusp1-/- : Zfp36aa/aa). The data provide a comprehensive picture of the impact of Dusp1 deletion or TTP mutation on the responses of primary macrophages to LPS. They also demonstrate that the excessive inflammatory responses of Dusp1-/- macrophages are largely a consequence of the phosphorylation and inactivation of TTP. Genome wide expression profiles of wild type, Dusp1-/-, Zfp36aa/aa and Dusp1-/-/Zfp36aa/aa M-CSF derived macrophages, stimulated with LPS for 1 or 4 hours
2015-05-15 | E-GEOD-68449 | biostudies-arrayexpress
Project description:The mitogen-activated protein kinase (MAPK) p38 pathway is reported to regulate macrophage responses to lipopolysaccharide (LPS) at least partly via the phosphorylation of the mRNA-destabilizing factor tristetraprolin (TTP). LPS-activated MAPK p38 phosphorylates and activates the downstream kinase MAPK-activated protein kinase 2 (MK2), which then phosphorylates serines 52 and 178 of TTP, resulting in loss of mRNA-destabilizing activity. As a consequence, mRNAs that contain binding sites for TTP are stabilized in a manner that is acutely sensitive to the activity of the MAPK p38 pathway. Dual specificity phosphatase 1 (DUSP1) dephosphorylates and inactivates MAPK p38. Dusp1-/- macrophages overexpress a number of pro-inflammatory mediators, but their genome-wide responses to LPS have not yet been described in detail. Dusp1-/- mice are exceptionally sensitive to a wide variety of inflammatory challenges, including experimental models of endotoxemia or sepsis. It has been suggested (but not yet proven) that DUSP1 controls the inflammatory response of macrophages in part via the regulation of MAPK p38 activity and TTP phosphorylation status. We generated a mouse knock-in strain, in which codons 52 and 178 of the endogenous Zfp36 gene (which encodes TTP) were mutated to alanine codons. The mutation gives rise to a constitutively active form of TTP, which cannot be inactivated via the p38 MAPK pathway. The Zfp36aa/aa strain was back-crossed against C57/BL6 for > 10 generations. We also generated a double-targeted strain in which the Zfp36 mutation was combined with disruption of the Dusp1 gene. This expression array describes LPS responses of primary mouse bone marrow-derived macrophages of four genotypes, and closely matched genetic background: wild type (Dusp1+/+ : Zfp36+/+); TTP mutant (Zfp36aa/aa); DUSP1 knock out (Dusp1-/-); and double targeted (Dusp1-/- : Zfp36aa/aa). The data provide a comprehensive picture of the impact of Dusp1 deletion or TTP mutation on the responses of primary macrophages to LPS. They also demonstrate that the excessive inflammatory responses of Dusp1-/- macrophages are largely a consequence of the phosphorylation and inactivation of TTP.
2015-05-15 | GSE68449 | GEO
Project description:Receptor tyrosine kinases (RTK) have an important role in arthritis severity and in models of rheumatoid arthritis (RA), but their regulation is not fully understood. The dual specificity phosphatase 6 (DUSP6) has been implicated in the regulation of RTK signaling, but never in the context of arthritis and autoimmunity. We used the KRN serum induced arthritis (KSIA) model of RA and show that DUSP6-/- mice were protected and had a 50% lower maximum arthritis score (P=0.006), and reduced joint damage than C57BL/6. Serum levels of IL10 were significantly increased (>two-fold), and IL6 decreased in DUSP6-/- mice. DUSP6-/- mice had increased numbers of IL10+ cells including Tr1 regulatory cells (P< 0.01). Introduction of the IL10-/- into DUSP6-/- (double KO) reversed the DUSP6-/- protection. In conclusion, this study reports a new pro-arthritic role for DUSP6. This new discovery has the potential generate a novel target for therapies for RA and inflammatory diseases.
2024-05-23 | GSE268216 | GEO
Project description:The present study identified the role of the Mitochondrial Fission Process 1 protein (MTFP1) in the mitochondrial and metabolic activity of the liver. Ablation of Mtfp1 liver cells alters mitochondrial function and confers a specific liver metabolic protection against high-fat diet
2023-06-15 | E-MTAB-12920 | biostudies-arrayexpress
Project description:Activation of the Mitogen activated protein kinase (MAPK) cascade following Toll-like receptor (TLR) stimulation enables innate immune cells to rapidly activate cytokine gene expression. A balanced response to signals of infectious danger requires that cellular activation is transient. Here, we identify the MAPK phosphatase Dual specificity phosphatase-1 (DUSP1) as an essential endogenous regulator of the inflammatory response to LPS. DUSP1-deficient (DUSP1-/-) bone marrow derived macrophages showed selectively prolonged activation of p38 MAPK and increased cytokine production. Intraperitoneal challenge of DUSP1-/- mice with LPS caused increased lethality and overshooting production of IL-6 and TNF. Transcriptional profiling revealed that DUSP1 controls a significant fraction of LPS-induced genes, that includes IL-6 and IL-10 as well as the chemokines CCL3, CCL4 and CXCL2. In contrast, the expression of the important mediators of endotoxin lethality, IFN? and IL-12, was not significantly altered by the absence of DUSP1. These data together demonstrate a specific regulatory role of DUSP1 in controlling a subset of LPS-induced genes that determines the outcome of endotoxin shock. Experiment Overall Design: Mice were injected intraperitoneally with E. coli LPS (10µg/g bodyweight) and sacrificed 6h later. Total spleen RNA (5 µg) was prepared, labeled and hybridized to Affymetrix MOE430A 2.0 GeneChips according to the manufacturer's instructions. Three biological replicates per condition were analysed. CEL Files were processed for global normalization and generation of expression values using the rma algorithm in the R affy package (www.bioconductor.org).
2007-11-01 | E-GEOD-3565 | biostudies-arrayexpress