The role of GSK3 on macrophage re-programming by high-dose methotrexate

Macrophage phenotypic and functional heterogeneity derives from tissue-specific transcriptional signatures shaped by the local microenvironment. M-CSF drives the generation of human monocyte-derived macrophages with a potent anti-inflammatory activity upon stimulation. One-carbon metabolism (OCM) is a complex network of biosynthetic pathways that includes de novo biosynthesis of purines and thymidylate, amino acid metabolism, and methylation reactions. Methotrexate (MTX) is an anti-folate drug used for Acute Lymphoblastic Leukemia treatment. We explored the molecular impact of blocking GSK3 a/b on the transcriptional effect of high-doses of MTX in M-CSF-primed human monocyte derived macrophages. Overall design: mRNA profiles of human monocyte-derived macrophages exposed to MTX and/or CHIR99021 for 48h. Monocytes were cultured for 5 days containing M-CSF (10 ng/ml) to generate M-CSF-polarized macrophages (M-MØ). M-CSF was added every two days. DMSO, Methotrexate (MTX, 5 µM), CHIR99021 (CHIR, 10 µM) or both (MTX+CHIR) were added once on 5 day-differentiated macrophages, and treatment maintained for 48h.