Project description:Macrophages require rapid and tightly controlled regulatory mechanisms to respond rapidly to environmental disruptions while preventing excessive inflammatory responses. While transcriptional regulation has been well-characterized in macrophage activation, whether and how translational control contributes to macrophage activation remains less understood. Here, we investigate the dynamic landscape of translational regulation in macrophages across acute, intermediate, and prolonged LPS exposure.
Project description:Primary objectives: Characterization of the macrophage population subset that is modulated by enteric neurons
Primary endpoints: Characterization of the macrophage population subset that is modulated by enteric neurons via RNA sequencing
Project description:When macrophages encounter pathogens, they transiently induce an orchestrated cascade of pro- and anti-inflammatory genes. We systematically analyzed the contribution of translational regulation to the early phase of macrophage activation. While the expression of most cytokines is regulated by changes in mRNA levels, de-repression of translation was found to permit expression of many feedback inhibitors of the inflammatory response. This includes NF-kB inhibitors (IkBd, IkBz, Nr4a1, Ier3), a p38 MAPK antagonist (Dusp1) and post-transcriptional suppressors of cytokine expression (TTP and Zc3h12a). Ier3 is tightly co-regulated with TNF at the level of mRNA abundance and translation. Macrophages lacking Ier3 show reduced survival upon activation, indicating that induction of Ier3 is required to protect macrophages from lipopolysaccharide-induced cell death. Our analysis reveals an important role of translational regulation in the resolution of inflammation and macrophage survival. RNA was purified from cytoplasmic lysate or polysome fractionation before and 1 h after stimulation of RAW264.7 macrophages with LPS. Fractions were pooled into four samples per condition: Free RNA (F), 40S-associated RNA (S), light (L) and heavy polysomes (H). The experiment was performed in three biological replicates, and RNA was quantified with GeneChip Mouse Gene 1.0 ST Arrays (Affymetrix).
Project description:When macrophages encounter pathogens, they transiently induce an orchestrated cascade of pro- and anti-inflammatory genes. We systematically analyzed the contribution of translational regulation to the early phase of macrophage activation. While the expression of most cytokines is regulated by changes in mRNA levels, de-repression of translation was found to permit expression of many feedback inhibitors of the inflammatory response. This includes NF-kB inhibitors (IkBd, IkBz, Nr4a1, Ier3), a p38 MAPK antagonist (Dusp1) and post-transcriptional suppressors of cytokine expression (TTP and Zc3h12a). Ier3 is tightly co-regulated with TNF at the level of mRNA abundance and translation. Macrophages lacking Ier3 show reduced survival upon activation, indicating that induction of Ier3 is required to protect macrophages from lipopolysaccharide-induced cell death. Our analysis reveals an important role of translational regulation in the resolution of inflammation and macrophage survival.
Project description:We analysed the polysomal mRNA and total mRNA during Col-0 seed maturation The aim was to investigate the translational dynamics during seed maturation.
Project description:It is not fully known whether translational regulation also occurs in later stage immune responses, such as effector-triggered immunity (ETI), which often leads to strong metabolic dynamics. In this study, we performed a genome-wide ribosome profiling in Arabidopsis upon ETI activation and discovered that specific groups of genes were translationally regulated, especially metabolic genes in aromatic amino acid, phenylpropanoid, camalexin, and sphingolipid metabolism. The involvement of these components in the induction of ETI was confirmed by genetic analysis, amino acid profiling and exogeneous application of phenylalanine or an inhibitor of aromatic amino acid biosynthesis. Our findings provide new insight into the diverse translational regulation in the plant immune responses and demonstrate that translational coordination of metabolic gene expression is an important strategy for ETI activation.
Project description:IFN-g primes macrophages for enhanced inflammatory activation by TLRs and microbial killing, but little is known about the regulation of cell metabolism or mRNA translation during priming. We found that IFN-g regulates macrophage metabolism and translation in an integrated manner by targeting mTORC1 and MNK pathways that converge on the selective regulator of translation initiation eIF4E. Physiological downregulation of the central metabolic regulator mTORC1 by IFN-g was associated with autophagy and translational suppression of repressors of inflammation such as HES1. Genome-wide ribosome profiling in TLR2-stimulated macrophages revealed that IFN-g selectively modulates the macrophage translatome to promote inflammation, further reprogram metabolic pathways, and modulate protein synthesis. These results add IFN-g-mediated metabolic reprogramming and translational regulation as key components of classical inflammatory macrophage activation. RPF and RNAseq libraries were generated from mock or IFN-g-primed human macrophages. Cells were stimulated with Pam3Cys and harvested at 4 hours. Libraries were generated using protocol modified from Illumina Truseq technology.
Project description:IFN-g primes macrophages for enhanced inflammatory activation by TLRs and microbial killing, but little is known about the regulation of cell metabolism or mRNA translation during priming. We found that IFN-g regulates macrophage metabolism and translation in an integrated manner by targeting mTORC1 and MNK pathways that converge on the selective regulator of translation initiation eIF4E. Physiological downregulation of the central metabolic regulator mTORC1 by IFN-g was associated with autophagy and translational suppression of repressors of inflammation such as HES1. Genome-wide ribosome profiling in TLR2-stimulated macrophages revealed that IFN-g selectively modulates the macrophage translatome to promote inflammation, further reprogram metabolic pathways, and modulate protein synthesis. These results add IFN-g-mediated metabolic reprogramming and translational regulation as key components of classical inflammatory macrophage activation. microRNA-seq libraries were generated from mock or IFN-g-primed human macrophages. Cells were stimulated with or without Pam3Cys and harvested at 4 hours Libraries were generated using Illumina Truseq small RNA technology.