Project description:Combining metabolomics analyses with an IFN-stimulated response elements reporter system, we identify spermine as a cellular metabolite brake for JAK1 signaling. Spermine directly binds to FERM and SH2 domains of JAK1 to impair IFNAR2-JAK1 interaction. Spermine suppresses JAK1 phosphorylation triggered by types I and II cytokines, including IFN-I/II, IL-2, and IL-6. Spermine treatment attenuates autoimmune pathogenesis in a SLE murine model and reduces IFN-I signaling in monocytes from SLE patients, which have reduced spermine levels.
Project description:Combining metabolomics analyses with an IFN-stimulated response elements reporter system, we identify spermine as a cellular metabolite brake for JAK1 signaling. Spermine directly binds to FERM and SH2 domains of JAK1 to impair IFNAR2-JAK1 interaction. Spermine suppresses JAK1 phosphorylation triggered by types I and II cytokines, including IFN-I/II, IL-2, and IL-6. Spermine treatment attenuates autoimmune pathogenesis in a SLE murine model and reduces IFN-I signaling in monocytes from SLE patients, which have reduced spermine levels.
Project description:Using an unbiased metabolomics approach and a IFN-stimulated response elements (ISRE) reporter screening system, we have identified the cellular metabolite spermine as an endogenous brake restraining IFN-I signaling and autoinflammation. Cellular spermine concentration decrease upon stimulations with IFN-I, IL-2, and IL-6. Spermine suppresses phosphorylation of JAK1 in macrophages responding to IFN-I, T cells responding to IL-2, and fibroblasts responding to IL-6. Mechanistically, spermine binds directly to the N-terminal domains of JAK1, resulting in impaired IFNAR2-JAK1 interaction required for initiating downstream signaling and, subsequently, restrained IFN-I effector response. Moreover, spermine attenuates SLE progression in an SLE murine model and reduces IFN-I signaling in PBMCs from SLE patients.
Project description:Maintaining tissue homeostasis depends on a balance of cell proliferation, differentiation and apoptosis. Polyamine regulator, AMD1, is a crucial regulator of keratinocyte differentiation and AMD1 protein is upregulated on differentiation and highly expressed in the suprabasal layers of the human epidermis. During keratinocyte differentiation, elevated AMD1 promotes decreased putrescine and increased spermine levels. Inhibition of AMD1 results in reduced spermine levels and inhibition of keratinocyte differentiation. Supplementing AMD1 inhibited keratinocytes with exogenous spermidine/spermine rescued aberrant differentiation. Undifferentiated and differentiated keratinocytes that had been treated with and without AMD1 inhibitor EGBG in the presence or absence of spermidine/ spermine supplementation were subjected to microarray analysis. These data show that AMD1 up regulation is required for keratinocyte differentiation and that inhibition of AMD1 can be rescued by supplementation with the polyamines spermidine and spermine.
Project description:PauA2 plays an essential role in spermine catabolism and that exogenous spermine exerts a bactericidal effect on the ΔpauA2 mutant of P. aeruginosa. Not only subjected to growth inhibition by spermine, the pauA2 mutant without a functional γ-glutamylpolyamine synthetase PauA2 became more sensitive to β-lactam antibiotics in human serum. To explore PauA2 as a potential target of drug development, suppressors of the pauA2 mutant were isolated from selection plates containing spermine. These suppressors share common changes in various phenotypes. Genome resequencing of a representative suppressor revealed a unique mutation at the phoU gene, and a constitutive expression of the Pho regulon as evidenced by measurements of transcriptome analysis.
Project description:The naturally occurring polyamines putrescine, spermidine or spermine are ubiquitous in all cells. Although polyamines have prominent regulatory roles in cell division and growth, precise molecular and cellular functions are not well established in vivo. In this work we have performed a microarray experiment in a polyamine mutant (delta-spe3 delta-fms1) strain to investigate the responsiveness of yeast genes to supplementation with spermidine and spermine. Expression analysis identified genes responsive to the addition of either excess spermidine (10-5 M) or spermine (10-5 M) compared to a control culture containing 10-8 M spermidine. 247 genes were up-regulated >2-fold, and 11 genes were up-regulated more than 10-fold after spermidine addition. Functional categorization of the genes showed induction of transport related genes, and genes involved in methionine, arginine, lysine, NAD and biotin biosynthesis. 268 genes were down-regulated more than 2-fold, and 6 genes were down-regulated more than 8-fold after spermidine addition. A majority of the down-regulated genes are involved in nucleic acid metabolism and various stress responses. In contrast, only few genes (18) were significantly responsive to spermine. Thus, results from global gene expression profiling demonstrate a more major role for spermidine in modulating gene expression in yeast than spermine. Experiment Overall Design: 5 control replicates vs. 3 spermine (SP)-treated or 5 spermidine (SPD)-treated samples.
Project description:For additional details see Bongers et al, Spermine Oxidase Maintains Basal Skeletal Muscle Gene Expression and Fiber Size, and Is Strongly Repressed by Conditions that Cause Skeletal Muscle Atrophy . Am J Physiol Endocrinol Metab. 2014 [under review] Bilateral tibialis anterior muscles of C57BL/6 mice were harvested seven days after transfection with spermine oxidase or control plasmid.
Project description:The naturally occurring polyamines putrescine, spermidine or spermine are ubiquitous in all cells. Although polyamines have prominent regulatory roles in cell division and growth, precise molecular and cellular functions are not well established in vivo. In this work we have performed a microarray experiment in a polyamine mutant (delta-spe3 delta-fms1) strain to investigate the responsiveness of yeast genes to supplementation with spermidine and spermine. Expression analysis identified genes responsive to the addition of either excess spermidine (10-5 M) or spermine (10-5 M) compared to a control culture containing 10-8 M spermidine. 247 genes were up-regulated >2-fold, and 11 genes were up-regulated more than 10-fold after spermidine addition. Functional categorization of the genes showed induction of transport related genes, and genes involved in methionine, arginine, lysine, NAD and biotin biosynthesis. 268 genes were down-regulated more than 2-fold, and 6 genes were down-regulated more than 8-fold after spermidine addition. A majority of the down-regulated genes are involved in nucleic acid metabolism and various stress responses. In contrast, only few genes (18) were significantly responsive to spermine. Thus, results from global gene expression profiling demonstrate a more major role for spermidine in modulating gene expression in yeast than spermine.