EB1089 promotes the expression of vitamin D receptor in the intestinal epithelial cell line HT-29 and reduces lipopolysaccharide-induced inflammatory response

BACKGROUND: EB1089 is a vitamin D receptor (VDR) agonist that reduces the inflammatory response. The specific pathway through which the inflammatory response is reduced is unclear, and this study is intended to investigate its effect on the inflammatory response through an LPS (lipopolysaccharide)-induced inflammation model of the intestinal epithelial cell line HT-29. METHODS: We divided HT-29 cells into a control group, LPS group, and LPS + EB1089 group. Cell proliferation was detected with a Cell Counting Kit-8 (CCK-8) kit, and the apoptosis rate was determined through flow cytometry, the lactate dehydrogenase (LDH), interleukin-18 (IL-18), and interleukin-1β (IL-1β) contents were measured with enzyme-linked immunosorbent assay (ELISA), and the expression levels of ASC, Caspase-1, NLRP3, VDR, TLR4, MYD88, NF-κB and other proteins in the cells were detected by western blot. RESULTS: Pretreatment with EB1089 pretreatment reduced the LPS-induced apoptosis of HT-29 cells. LDH content was evidently lower in the LPS + EB1089 group than in the LPS group. The LDH content in the LPS + EB1089 group was evidently lower than that in the LPS group. The protein expression levels of ASC, Caspase-1, NLRP3, TLR4, MyD88, and NF-κB in the LPS group were evidently increased compared with those in the control group; however, the protein expression of VDR evidently decreased. The protein expression levels of Caspase-1, NLRP3, TLR4, MyD88, and NF-κB in the LPS + EB1089 group were evidently lower than those in the LPS group; however, the VDR protein expression evidently increased in the LPS + EB1089 group. CONCLUSIONS: EB1089 promoted the VDR expression and reduced the LPS induced inflammation in HT-29 cells.