Itaconate and dimethyl itaconate upregulate IL-6 production in the LPS-induced inflammation in mice.

Itaconate is one of the most studied immunometabolites produced by myeloid cells during inflammatory response. It mediates a wide range of anti-inflammatory and immunoregulatory effects and plays a role in a number of pathological states, including autoimmunity and cancer. Itaconate and its derivatives are considered as potential therapeutic agents for treatment of inflammatory diseases. While immunoregulatory effects of itaconate have been extensively studied in vitro and using knock-out mouse models, less is known about how therapeutic administration of this metabolite regulates inflammatory response in vivo. Here, we investigate the immunoregulatory properties of exogenous administration of itaconate (ITA) and its derivative dimethyl itaconate (DI) in a mouse model of LPS-induced inflammation. The data show that administration of ITA or DI controls systemic production of multiple cytokines, including increased IL-10 production. However, only DI was able to suppress systemic production of IFNγ and IL-1β. In contrast to in vitro data, administration of ITA or DI in vivo resulted in systemic upregulation of IL-6 in the blood. Electrophilic stress due to ITA or DI was not responsible for IL-6 upregulation. However, inhibition of SDH with dimethyl malonate (DM) also resulted in elevated systemic levels of IL-6 and IL-10. Taken together, our study reports a novel effect of exogenous itaconate and its derivative DI on the production of IL-6 in vivo, with important implications for the development of itaconate-based anti-inflammatory therapies.