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Aim To observe the proteetive effect of meseneephalie astrocyte-de rived neurotrophic faetor (MANF) on intestinal epithelial eells under endoplas- mic reticulum stress (EH stress).Methods Normal human intestinal epithelial cell line FHs74Int was stimulated with EH stress inducers, tunicmycin (TM) and TNF-cx, then the expression of endogenous MANF was observed.The recombinant plasmids MANF-GFP and GFP were transfected into FHs74Int cells individually, the transfection efficiency was observed by fluorescence j j microscopy, and the effect of MANF on EH stress was observed by Western blot.The effect of MANF on the proliferation of intestinal epithelial cells stimulated by TM was detected via CCK-8 assay.The effect of MANF on apoptosis after EH stress was detected by Western blot and flow cytometry.Results EH stress could induce the expression of endogenous MANE in intestinal epithelial cells.Overexpression of MANE significantly inhibited the expression of the EH stress-related proteins, Bip and CHOP, and promoted the proliferation of intestinal epithelial cells.At the same time, it could reduce the production of the proapoptotic proteins cleaved-c a spa se-3 and Bax, increase the expression of the antiapoptotic protein Bcl-2, and inhibit the proportion of early and late apoptosis of intestinal epithelial cells.Conclusions MANF plays a protective role in inhibiting EH stress in intestinal epithelial cells by promoting cell proliferation and reducing apoptosis.
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PURPOSE: We investigated compounds from food sources given to children that may induce the differentiation of small intestinal epithelial cells in order to signal pathways that induce the prolif eration and differentiation of small intestinal epithelial cells. METHODS: We analyzed small intestinal epithelial cell differentiation using in vitro IEC-6 cells model. The growth curve of IEC-6 cells was obtained by standard MTT assay. Alkaline phospha tase(ALP) activities were determined using the paranitrophenol colorimetric assay for the differ entiation of IEC-6 cells. We did ALP and Brdu double-staining of cultured IEC-6 cells to distin guish between differentiation and proliferation, and investigated compounds' potential for inducing differentiation of small intestinal epithelial cells and protein kinase signal pathway. RESULTS: The calcium ion was essential for the differentiation of IEC-6 cells. Retinol and retinoic acid induced the differentiation of IEC-6 cells. beta-LG stabilized and increased cell permeation of retinoic acid. IEC-6 cells showed 3 or 4 times more ALP activity with co-treatment of retinoic acid and beta-LG. BSA and OVA accelerated differentiation of IEC-6 cells in a similiar fashion to beta -LG. But, pepton and casein didn't. Heat destruction of beta-LG, BSA and OVA lead to loss in the ability of these compounds to induce cellular differentiation. The PKA signal pathway involved differentiation of IEC-6 cells. IEC-6 cells proliferation increased by the activation of PKC signal pathway and decreased differentiation by PKC signal pathway. CONCLUSION: Our results confirm that signal pathways are related to the proliferation and differ entiation of small intestinal epithelial cells and various compounds from food sources of childhood, such as beta-LG, BSA, OVA, and retinoic acid. These compounds appear to induce differentiation of small intestinal epithelial cells and may play a role in stimulating regeneration of epithelial cells after small intestinal mucosal injury.