AIM:To observe the effect of continuous light on the structure and differential metabolites of gut microbiota in mice.METHODS:The mice were randomly divided into normal light(light/dark,LD)group and 24-hour continuous light(light/light,LL)group.The body weight,fasting blood glucose,serum free fatty acids,serum triacylglycerol and serum total cholesterol levels of each group of mice were measured after 10 weeks.Fresh feces were collected,and 16S rRNA sequencing technology was used to study the effect of continuous light on the diversity,structure,and species composition of gut microbiota in mice.Additionally,liquid chromatography-mass spectrometry(LC-MS)analysis was per-formed to observe the effect of continuous light on the metabolites in mice.RESULTS:Compared with the LD group,the body weight,fasting blood glucose and lipid levels of the LL group were increased(P＜0.05).At the phylum level,the proportion of Firmicutes in the LL group increased,while the proportion of Bacteroidetes decreased.At the class level,the abundance of norank_f_Muribaculaceae and Prevotellaceae_UCG-001 in the LL group decreased significantly,while the abundance of Lactobacillus,Turicibacter and Odoribacter increased significantly.Non-targeted metabolomics analysis iden-tified 65 and 73 differential metabolites under positive and negative modes,involving six major metabolic pathways,in-cluding ABC transporters,purine metabolism,pyrimidine metabolism,secondary bile acid biosynthesis,protein digestion and absorption,and choline metabolism in cancer.CONCLUSION:The structure and metabolites of gut microbiota in mice exposed to continuous light are relatively specific,and inosine may be a key biomarker and potential therapeutic tar-get for biological clock disorders.

AIM:To observe the effect of continuous light on the structure and differential metabolites of gut microbiota in mice.METHODS:The mice were randomly divided into normal light(light/dark,LD)group and 24-hour continuous light(light/light,LL)group.The body weight,fasting blood glucose,serum free fatty acids,serum triacylglycerol and serum total cholesterol levels of each group of mice were measured after 10 weeks.Fresh feces were collected,and 16S rRNA sequencing technology was used to study the effect of continuous light on the diversity,structure,and species composition of gut microbiota in mice.Additionally,liquid chromatography-mass spectrometry(LC-MS)analysis was per-formed to observe the effect of continuous light on the metabolites in mice.RESULTS:Compared with the LD group,the body weight,fasting blood glucose and lipid levels of the LL group were increased(P＜0.05).At the phylum level,the proportion of Firmicutes in the LL group increased,while the proportion of Bacteroidetes decreased.At the class level,the abundance of norank_f_Muribaculaceae and Prevotellaceae_UCG-001 in the LL group decreased significantly,while the abundance of Lactobacillus,Turicibacter and Odoribacter increased significantly.Non-targeted metabolomics analysis iden-tified 65 and 73 differential metabolites under positive and negative modes,involving six major metabolic pathways,in-cluding ABC transporters,purine metabolism,pyrimidine metabolism,secondary bile acid biosynthesis,protein digestion and absorption,and choline metabolism in cancer.CONCLUSION:The structure and metabolites of gut microbiota in mice exposed to continuous light are relatively specific,and inosine may be a key biomarker and potential therapeutic tar-get for biological clock disorders.

Aim To investigate the effect of MTX(included(±)MTX,(+)MTX and(-)MTX)on the proliferation of ECV304 cells and to explore its mechanisms.Methods ECV304 cells were cultured.The cell proliferation was determined by MTT.The morphological changes were inspected by inverted microscope.Cell cycle phases were assayed by propidium iodide staining flow cytometry.Results ECV304 cells were treated with(+)MTX,(-)MTX and(±)MTX at 1～150 μmol·L~(-1) for 24,48,72 h.The results showed that the proliferation of ECV304 cells was significantly inhibited under different conditions.The order of the inhibited efficacy was(+)MTX>(±)MTX>(-)MTX.The morphology of ECV304 cells were changed by(+)MTX,(-)MTX and(±)MTX treatment,which included the cell shrinkage,chromatin condensation.After administration of 10 μmol·L~(-1) of(+)MTX,(-)MTX and(±)MTX for 48 h,the cell cycle phases were assayed by propidium iodide staining flow cytometry.The result showed DNA replication was interfered by(+)MTX,(-)MTX and(±)MTX treatment.Conclusions The proliferation of ECV304 cells has the chiral selective effects by(+)MTX and(-)MTX treatment,and the inhibition on ECV304 cells proliferation of(+)MTX is significantly stronger than that of (-)MTX.