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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: Blotting, Western, Cytokines, Gas Chromatography-Mass Spectrometry, Gene Expression Regulation, Humans, Immunohistochemistry, Intestinal Neoplasms, Mucins, Neoplasm Proteins, RNA, Messenger, RNA, Neoplasm, Reverse Transcriptase Polymerase Chain Reaction, Tumor Cells, Cultured.
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Do proinflammatory cytokines trigger MUC gene expression and mucin release in the intestinal cancer cell line LS180? Context: Proinflammatory cytokines and a defective mucus layer are involved in the pathogenesis of colitis. Therefore, we determined cytokine effects on MUC gene expression and mucin secretion. LS180 cells were characterized by light and electron microscopy and subsequently exposed to interleukin 1 (IL-1, 1 ng/ml), interleukin 6 (IL-6, 10 ng/ml), or tumor necrosis factor-alpha (TNFalpha, 10 ng/ml). MUC gene (MUC2, MUC5AC, MUC5B, MUC6) mRNA expression was assessed by RT-PCR, the encoded proteins were identified by immunocytochemistry and Western blotting, and the released mucins were isolated and chromatographically characterized. Thirty to 40% of the cells contained intracellular mucin granules. Incubation with IL-1 transiently stimulated the mRNA expression of MUC2 and MUC5AC, whereas IL-6 induced an early response of MUC2, MUC5B and MUC6. TNFalpha upregulated the expression of MUC2 and MUC5B for 3 hours, and had no effect on the expression of MUC 5AC and MUC6. Immunocytochemistry and Western blotting confirmed TNFalpha effects on MUC2 and MUC5AC on the protein levels. All cytokines stimulated the release of less glycosylated mucins and considerably modulated their carbohydrate composition.
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Our data demonstrate differential cytokine effects on mucin synthesis, secretion and composition. These alterations may contribute to the defective mucus layer in colitis. Final Decision: yes