A methotrexate-induced in vitro organoid mucositis model

Introduction Chemotherapy-induced intestinal mucositis is frequently a doselimiting and costly side effect for which there is no treatment available. Here, we investigate whether intestinal organoids, a threedimensional in vitro tissue model incorporating many of the physical relevant features of the in vivo tissue, could be used to develop an in vitro mucositis model in which both mucositis development and recovery can be studied. Objectives To develop an in vitro model of methotrexate (MTX)-induced mucositis in small intestinal organoids. Methods Mice derived intestinal organoids were treated with different concentrations of MTX for 24-96 hours after which the metabolic activity was measured. Recovery of the metabolic activity was studied 24-96 hours after removal of the MTX. Citrulline and other amino acids concentrations were determined in themedia. The inflammatory status of theMTXtreated organoids was studied by analyzing the cytokine and chemokine levels. Results Treatment with 100 ng/ml MTX for 96 hours decreased the metabolic activity of the organoids to 50% while ensuring recovery. The citrulline levels in the media were significantly reduced from 78 μM to 52 μM whereas the production of several chemokines significantly increased. Conclusions Intestinal organoids can be used for studying the initial response of the intestine to MTX treatment. Moreover, the described model might be suitable for screening interventions aiming to improve the course of intestinal mucositis, thereby potentially decreasing the number of animal experiments.