Modulation of proliferation, apoptosis and inflammation of Caco-2 epithelial cells and THP-1 macrophage-like monocytes in LPS stimulated co-culture model

BACKGROUND AND OBJECTIVES: Epithelial cells and macrophages play major roles in modulating the state of inlammatory response regulated by intracellular signaling pathways.The aim of this study was to characterize changes in cell proliferation, apoptosis and infl ammation related intracellular signalling pathways MAPKs and NF-κB in Caco-2 epithelial cells and THP-1 macrophage-like monocytes contacted and fi lterseperated co-cultures in the presence of LPS stimulation.METHODS: We assessed the apoptosis and infl ammation by measuring caspase-3 activity, TNF-α and IL-10 cytokines, total and phosphorylated forms of intracellular signalling pathway molecules p53, JNK, Jun, ERK, p38, NF-κB p65 and IkB.RESULTS: The contacted co-culture of Caco-2 and THP-1 cells represented higher levels of JNK, jun and p38 MAPK pathway proteins associated with cell proliferation, whereas apoptosis related molecule caspase-3 and p53 increased in the fi lter-separated co-culture condition.Also, the contacted co-culture condition led to proinfl ammatory changes in NF-κB signalling pathways and cytokine responses with high phosphorylated NF-κB p65 and TNF-α, and low I-κB and IL-10 levels.CONCLUSION: Epithelia -monocytes co-culture stimulated with LPS regulated cell proliferation and infl ammation in a contact dependent manner, whereas apoptosis was associated with non-contacted cell culture condition.Thus, co-culture models are important models for explaining the immunopathologies in the mucosal areas (Fig. 5, Ref. 30).