Abstract：Abstract: In order to study the effects of dexmedetomidine on inflammation, proliferation and apoptosis of human colonic epithelial NCM-460 cells induced by lipopolysaccharide (LPS) and the regulation of phosphatidylinositol-3-kinase/serine-threonine kinase (PI3K/AKT) signaling pathway, we cultured human colonic epithelial NCM-460 cells in vitro, they were divided into control group, LPS group (1 μg/mL LPS) and dexmedetomidine groups with different mass concentrations (1 μg/mL LPS+1.25, 2.50, 5.00 and 10.00 μg/mL dexmedetomidine). After 24 hours’ intervention, the appropriate mass concentration of dexmedetomidine was screened out for subsequent experiments. Then, The human colonic epithelial NCM-460 cells were divided into control group, LPS group, dexmedetomidine group (1 μg/mL LPS+5.00 μg/mL dexmedetomidine), LY294002 group (1 μg/mL LPS+10 μmol/L PI3K/AKT pathway inhibitor LY294002) and inhibitor group (1 μg/mL LPS+ 5.00 μg/mL dexmedetomidine +10 μmol/L LY294002), and activator group (1 μg/mL LPS+5.00 μg/mL dexmedetomidine +10 μmol/L PI3K/AKT pathway agonist SC79) were intervened for 24 hours. Cell viability was detected by live cell counting kit-8 (CCK-8). The expression levels of tumor necrosis factor-α (TNF-α) and interleukin -8(IL-8) were detected by enzyme-linked immunosorbent assay (ELISA). The cell proliferation rate was determined by 5- ethynyl -2' deoxyuridine (EdU). The apoptosis rate was determined by Hoechst 33258 staining. The expression levels of cyclin D1, cleaved cysteine protease 3 (cleaved Caspase 3) and key proteins of PI3K/AKT signaling pathway in cells were determined by Western blot (WB). According to the cell viability and the expression level of inflammatory factor TNF-α, 5.00 μg/mL dexmedetomidine was selected for the follow-up experiment. The results showed that compared with the control group, the cell proliferation rate and the expression level of Cyclin D1 in LPS group significantly decreased (P<0.05), while the cell apoptosis rate, the expression levels of TNF-α, IL-8, and cleaved Caspase 3, the ratio of p-PI3K/PI3K and p-AKT/AKT significantly increased (P<0.05). Dexmedetomidine and LY294002 in dexmedetomidine group and LY294002 group reversed the above-mentioned effects of LPS on human colonic epithelial NCM-460 cells (P<0.05). Compared with dexmedetomidine group, LY294002 in inhibitor group enhanced the effect of dexmedetomidine on human colonic epithelial NCM-460 cells induced by LPS (P<0.05), while SC79 in activator group weakened the effect of dexmedetomidine on human colonic epithelial NCM-460 cells induced by LPS (P<0.05). Studies have shown that dexmedetomidine can promote the proliferation of human colonic epithelial NCM-460 cells induced by LPS and inhibit its inflammation and apoptosis, and its mechanism may be related to blocking the signal transduction of PI3K/PI3K signaling pathway. This study can provide a new direction for the treatment of colitis.
Key words: ulcerative colitis; human colonic epithelial cells; dexmedetomidine; phosphatidylinositol-3-kinase/serine-threonine kinase
（Acta Laser Biology Sinica, 2024, 33(4): 377-384）
