摘要
ObjectiveThis study aims to investigate the mechanism in which Celastrus orbiculatus extract （COE） affects the proliferation and differentiation of gastric organoids and the expression of Lgr5 and thus reverses the precancerous lesions of gastric cancer （PLGC） by regulating the leucine-rich repeat containing G protein-coupled receptor 5 （Lgr5）/Wingless （Wnt）/β-catenin signaling pathway based on a gastric organoid injury model. MethodGastric organoids were established based on stem cells of the mouse gastric gland. Gastric organoid injury models were constructed by treating gastric organoids with N-methyl-N'-nitro-N-nitrosoguanidine （MNNG， 0.02 mg·L-1）. Gastric organoid injury models were randomly divided into normal group， model group （0.02 mg·L-1 MNNG）， low， medium， and high dose （5， 10， 20 mg·L-1） groups of COE， and Wnt inhibitor Dickkopf-related protein 1 （DKK1） （0.5 mg·L-1） group， and they were treated with respective agents for 24 h. The number and volume of gastric organoids under different drug concentrations were observed under a microscope. The viability of the gastric organoid injury models was detected by Methyl thiazolyl tetrazolium （MTT） assay. The morphology and pathology of gastric organoids were observed using Hematoxylin and Eosin （HE） staining. The expression levels of Lgr5， Mucin2 （MUC2）， Mucin5AC （MUC5AC）， Mucin6 （MUC6）， Wnt， and β-catenin in gastric organoids under different drug concentrations were detected by Western blot （WB）. ResultCompared with the normal group， the number， volume， and activity of gastric organoids in the model group were decreased （P<0.01）， while the expressions of Lgr5， MUC2， Wnt， and β-catenin were significantly increased （P<0.01）. The expressions of MUC5AC and MUC6 were significantly decreased （P<0.01）. Compared with the model group， the number and volume of gastric organoids in the low， medium， and high dose groups of COE were all improved （P<0.01）， and the vitality of gastric organoids was significantly enhanced （P<0.01）. The effect was the most significant at a COE concentration of 20 mg·L-1 （P<0.01）. The expressions of Lgr5 and MUC2 in the medium and high dose groups of COE were significantly reduced （P<0.01）， while the expression of MUC5AC and MUC6 were significantly increased in the low， medium， and high dose groups of COE （P<0.05， P<0.01）. Compared with the model group， Wnt inhibitors could promote the expression of MUC5AC and MUC6 in gastric organoids （P<0.05， P<0.01） and reduce the expression of MUC2， Wnt， and β-catenin. In addition， the combined use of COE at high concentrations and Wnt inhibitors could further promote this trend （P<0.01）. ConclusionCOE inhibits the Wnt/β-catenin pathway by inhibiting the expression of Lgr5， MUC2， Wnt， and β-catenin and promoting the expression of MUC5AC and MUC6， thus promoting the proliferation and differentiation of gastric organoids and reversing the PLGC process.