Project description:Polyamines, crucial molecules involved in cell proliferation and growth, play a pivotal role in cancer development and progression. Within the tumor microenvironment, macrophages, key components of the immune system, exhibit a complex relationship with polyamines. Evidence suggests that polyamines can modulate macrophage polarization, influencing their functional phenotypes. Here, we detected the gene DNA methylation changes in spermine-stimulated human macrophages isolated from PBMCs and TAMs.
Project description:Polyamines, crucial molecules involved in cell proliferation and growth, play a pivotal role in cancer development and progression. Within the tumor microenvironment, macrophages, key components of the immune system, exhibit a complex relationship with polyamines. Evidence suggests that polyamines can modulate macrophage polarization, influencing their functional phenotypes. Here, we detected the gene expression changes in spermine-stimulated human macrophages isolated from PBMCs.
Project description:Polyamines are essential for various cell functions and are produced in most cells, as well as being taken up from extracellular sources. Polyamines, especially spermine, in blood cells increase when polyamines are supplied from the digestive tract. Altered polyamine metabolism has an impact on substrate concentrations and enzyme activities involved in gene methylation, and may affect gene expression. Therefore, we investigated the effect of decreased polyamine synthesis and extracellular spermine supply on substrate concentrations and enzyme activities involved in gene methylation and on changes of methylation in promoter regions using methylation arrays. In Jurkat cells and human mammary epithelial cells, changes in polyamine concentrations differed after polyamine synthesis inhibition. However, S-adenosylmethionine decarboxylase activity and the decarboxylated S-adenosylmethionine to S-adenosyl-L-methionine ratio were decreased by spermine addition in both cells. After inhibiting polyamine synthesis in Jurkat cells by D,L-alpha-difluoromethylornithine, the protein levels of DNA methyltransferase (DNMT) 1, 3A and 3B were not changed, but the activity of the three enzymes markedly decreased. The protein levels of these enzymes were not changed by addition of spermine; however, DNMT 3B was markedly activated and DNMT 3A was also activated. DNMT 1 was not activated. Effects on methylation of promoter regions included significant changes for tumor suppressor genes in response to altered polyamine metabolism. However, no significant changes in methylation status were found on genes of which methylation status and their related protein levels were affected by spermine. When considering these results, there are many genes for which polyamines have an impact on expression via methylation of promoter regions.
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:Disturbances in tumor cell metabolism reshape the tumor microenvironment (TME) and impair antitumor immunity, but the implicit mechanisms remain elusive. Here, we found that spermine synthase (SMS) was significantly upregulated in tumor cells, which correlated positively with immunosuppressive microenvironments and predicted poor survival in hepatocellular carcinoma (HCC) patients. Via “subcutaneous” and “orthotopic” HCC syngeneic mouse models and a series of in vitro coculture experiments, we identified elevated SMS level in HCC cells played a role in immune escape mainly through its metabolic product spermine, which induced tumor-associated macrophage (TAM) reprogramming and subsequently corresponded with a decreased antitumor functionality of CD8+ T cells. Mechanistically, we discovered that spermine reprogrammed TAM mainly by activating the PI3K-Akt-mTOR-S6K signaling pathway. Spermine inhibition in combination with immune checkpoint blockade effectively diminishes tumor burden in vivo. Our results expand the understanding of the critical role of metabolites in regulating cancer progression and anti-tumor immunity, and open new avenues for developing novel therapeutic strategies against HCC.
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:To explore the Spermine(Spm)-based antibacterial targets in S. aureus, time course-dependent transcriptome analysis was conducted on Mu50 (MRSA) in the absence and presence of Spm. We conducted five independent microarray experiments in the absence (control) and the presence (experimental) of Spm. We calculated fold change as the ratio between the signal of untreated (control) and Spm-treated (experimental) cultures for 15, 30 and 60 min exposures.