Red Algae-Derived Mineral Intervention to Counter Pro-inflammatory Activity in Human Colon Organoids

Abstract

Human colon organoids were maintained in culture medium alone or exposed to lipopolysaccharide with a combination of three pro-inflammatory cytokines (tumor necrosis factor-α, interleukin-1β and interferon-γ [LPS-cytokines]) to mimic the environment in the inflamed colon. Untreated organoids and those exposed to LPS-cytokines were concomitantly treated with a multi-mineral product that has previously been shown to improve barrier structure/function. The organoids were subjected to proteomic analysis to obtain a broad view of the protein changes induced by these interventions. In parallel, confocal fluorescence microscopy and trans-epithelial electrical resistance measurements were used to assess barrier structure/function. The LPS-cytokines altered expression of multiple proteins that influence innate immunity and promote inflammation. Most of these were unaffected by the multi-mineral intervention, though a subset of inflammation-related proteins including fibrinogen-β and -γ chains, phospholipase A2 and SPARC was down-regulated in the presence of the multi-mineral intervention; another subset of proteins with anti-inflammatory, antioxidant or anti-microbial activity was up-regulated by multi-mineral treatment. When used alone, the multi-mineral intervention strongly up-regulated proteins that contribute to barrier formation and tissue strength. Concomitant treatment with LPS-cytokines did not inhibit barrier formation in response to the multi-mineral intervention. Altogether, the findings suggest that mineral intervention may provide a novel approach to combating inflammation in the colon by improving barrier structure/function as well as by directly altering expression of pro-inflammatory proteins.