Identification of a Class of Small Molecules That Up-Regulate Production of Anti-Inflammatory Cytokine IL10 Via Inhibition of GSK3β (51.10)

Abstract Interleukin-10 (IL-10), also known as human cytokine synthesis inhibitory factor (CSIF), is an anti-inflammatory cytokine produced primarily by monocytes and to a lesser extent by lymphocytes. This cytokine exhibits pleiotropic effects in immunoregulation and inflammation and is capable of inhibiting synthesis of various pro-inflammatory cytokines such as IFNγ, IL-2, IL-3, IL-6, TNFα and GM-CSF made by cells such as macrophages and Th-1 cells. During the course of our investigation to find small molecules that are capable of inhibiting the production of a pro-inflammatory cytokine, IL-23, we came across a sub-set of small molecules that exhibited an interesting property of up-regulating expression of IL-10 besides inhibiting IL-23 production. Such observation prompted us to further investigate the mechanism of action and target identification for this class of compounds. Preliminary experiments revealed that enhanced IL-10 production upon LPS stimulation of human THP-1 monocytic cells in the presence of compounds appears to be due to inhibition of GSK3β kinase. Results from these studies were further substantiated by screening the lead candidate against a panel of kinases in-vitro including GSK3β and a cell-based β-cateinin accumulation assay that directly measures GSK3β kinase on-target activity.