BACKGROUND:Kaempferol has anti-osteoporotic effects,but the mechanisms by which kaempferol regulates gut microbiota and metabolites to prevent and treat osteoporosis remain unclear.OBJECTIVE:To exploring the potential mechanisms by which kaempferol inhibit osteoporosis based on gut microbiota and comprehensive targeted metabolomics.METHODS:Eighteen female Sprague-Dawley rats were randomly divided into three groups:sham operation group,model group,and kaempferol group,with 6 rats in each group.Animal models of osteoporosis were made in the latter two groups through removal of bilateral ovaries.Eight weeks after modeling,the sham operation and model groups were gavaged with distilled water,and the kaempferol group was gavaged with 40 mg/kg kaempferol.Continuous administration in each group was carried out for 12 weeks.Rat fecal samples were collected for 16S rDNA amplicon sequencing to observe changes in the gut microbiota structure.Serum samples were subjected to comprehensive targeted metabolomics analysis using ultra-high performance liquid chromatography-tandem mass spectrometry technology,along with a proprietary database and multivariate statistical analysis.RESULTS AND CONCLUSION:After 12 weeks of continuous intervention,the results of 16S rDNA amplicon sequencing showed that compared with the sham operation group,the abundance of gut microbiota increased in the model group.Compared with the model group,kaempferol group exhibited a statistically significant increase in the abundance of the genus Latilactobacillus(P=0.021),while the abundances of Pantoea(P=0.034),Enterorhabdus(P=0.000),Monoglobus(P=0.024),Butyricimonas(P=0.034),Rothia(P=0.043),and Clostridia(P=0.004)were significantly downregulated.After 12 weeks of continuous intervention,the results of the serum samples analyzed by broad-targeted metabolomics revealed that 120 and 79 metabolites were identified between the sham operation and model groups and between the model and kaempferol groups,respectively.Among the three groups,there were 17 overlapping differentially expressed metabolites,including Cis-aconitic acid,barbituric acid,L-homocitrulline,3,4,5-trimethoxycinnamic acid,L-3-phenyllactic acid,cyclo(pro-pro),L-phenylalanine-L-serine,proline-isoleucine,L-donoraminoacetic acid-L-phenylalanineacetic acid,and phenylalanine-aspartic acid.Most of them belong to amino acids and their metabolites,glycerophospholipids and fatty acyls.The Kyoto Encyclopedia of Genes and Genomes pathways involved in the differential metabolites were mainly enriched in D-amino acid metabolism,histidine metabolism,propionate metabolism,lysine degradation,fatty acid metabolism and sphingolipid metabolism.After 12 weeks of continuous intervention,combined analysis revealed that genera such as Enterorhabdus,Latilactobacillus,Rothia,and Ruminococcus were closely associated with differential serum metabolites.To conclude,kaempferol may exert its anti-osteoporotic effects by modulating the abundance,diversity,and structure of gut microbiota,thereby regulating the metabolism of amino acids,their metabolites,and fatty acids.

BACKGROUND:Kaempferol has anti-osteoporotic effects,but the mechanisms by which kaempferol regulates gut microbiota and metabolites to prevent and treat osteoporosis remain unclear.OBJECTIVE:To exploring the potential mechanisms by which kaempferol inhibit osteoporosis based on gut microbiota and comprehensive targeted metabolomics.METHODS:Eighteen female Sprague-Dawley rats were randomly divided into three groups:sham operation group,model group,and kaempferol group,with 6 rats in each group.Animal models of osteoporosis were made in the latter two groups through removal of bilateral ovaries.Eight weeks after modeling,the sham operation and model groups were gavaged with distilled water,and the kaempferol group was gavaged with 40 mg/kg kaempferol.Continuous administration in each group was carried out for 12 weeks.Rat fecal samples were collected for 16S rDNA amplicon sequencing to observe changes in the gut microbiota structure.Serum samples were subjected to comprehensive targeted metabolomics analysis using ultra-high performance liquid chromatography-tandem mass spectrometry technology,along with a proprietary database and multivariate statistical analysis.RESULTS AND CONCLUSION:After 12 weeks of continuous intervention,the results of 16S rDNA amplicon sequencing showed that compared with the sham operation group,the abundance of gut microbiota increased in the model group.Compared with the model group,kaempferol group exhibited a statistically significant increase in the abundance of the genus Latilactobacillus(P=0.021),while the abundances of Pantoea(P=0.034),Enterorhabdus(P=0.000),Monoglobus(P=0.024),Butyricimonas(P=0.034),Rothia(P=0.043),and Clostridia(P=0.004)were significantly downregulated.After 12 weeks of continuous intervention,the results of the serum samples analyzed by broad-targeted metabolomics revealed that 120 and 79 metabolites were identified between the sham operation and model groups and between the model and kaempferol groups,respectively.Among the three groups,there were 17 overlapping differentially expressed metabolites,including Cis-aconitic acid,barbituric acid,L-homocitrulline,3,4,5-trimethoxycinnamic acid,L-3-phenyllactic acid,cyclo(pro-pro),L-phenylalanine-L-serine,proline-isoleucine,L-donoraminoacetic acid-L-phenylalanineacetic acid,and phenylalanine-aspartic acid.Most of them belong to amino acids and their metabolites,glycerophospholipids and fatty acyls.The Kyoto Encyclopedia of Genes and Genomes pathways involved in the differential metabolites were mainly enriched in D-amino acid metabolism,histidine metabolism,propionate metabolism,lysine degradation,fatty acid metabolism and sphingolipid metabolism.After 12 weeks of continuous intervention,combined analysis revealed that genera such as Enterorhabdus,Latilactobacillus,Rothia,and Ruminococcus were closely associated with differential serum metabolites.To conclude,kaempferol may exert its anti-osteoporotic effects by modulating the abundance,diversity,and structure of gut microbiota,thereby regulating the metabolism of amino acids,their metabolites,and fatty acids.

Objective:To investigate the prognosis and outcome of patients with chronic hepatitis C (CHC) related cirrhosis after achieved sustained virologic response (SVR) treated with direct-acting antiviral agent (DAA).Methods:Ninety-five patients diagnosed with CHC related cirrhosis who had complete data in Tianjin Second People′s Hospital from January 2014 to June 2017 were retrospectively followed up. Among them, 72 patients were treated with DAA and all of them achieved SVR, and the other 23 patients did not receive any antiviral therapy. The differences of mortality and incidence of hepatocellular carcinoma (HCC) between DAA treatment group and non-antiviral treatment group were compared. Statistical analysis was performed by independent sample t test, Mann-Whitney U test and chi-square test. Results:At the end of follow-up for three to 71 months, patients in DAA treatment group had a significant improvements in alanine aminotransferase, aspartate aminotransferase, albumin and liver stiffness measurement compared with those before treatment (42(23, 61) U/L vs 18(13, 28) U/L, 54(37, 75) U/L vs 23(18, 28) U/L, 39(33, 42) g/L vs 45(41, 48) g/L, 26(18, 37) kPa vs 15(11, 26) kPa, respectively, Z=-6.005, -7.008, -6.057 and -3.162, respectively, all P<0.01). However, there were no significant differences in incidence of HCC (12%(9/72) vs 17%(4/23)) and mortality (3%(2/72) vs 13%(3/23)) between the DAA treatment group and non-antiviral treatment group (both P>0.05). There was no significant difference of cumulative incidence of HCC in DAA treatment group compared with non-antiviral treatment group ( P=0.609). The age of patients progressed to HCC was older than those without HCC ((60.3±3.6) years vs (54.4±9.9) years, t=-3.948, P<0.01). In subgroup analysis, among the six patients with HCC, four had diabetes, the prevalence of diabetes in the patients without HCC was 17%(7/42); the level of fasting blood glucose (FBG) ((7.3±1.9) mmol/L vs (5.9±1.1) mmol/L) were higher in patients progressed to HCC than those without HCC in DAA treatment group with compensated cirrhosis ( χ2=7.430 and t=-2.442, respectively, both P=0.019). Conclusions:DAA treatment could notably improve liver function and alleviate liver fibrosis, but could not reduce the mortality and incidence of HCC in patients with CHC related cirrhosis significantly. Diabetes and high level FBG may be the risk factors for occurrence of HCC in patients with CHC related compensated cirrhosis.

Cloning of flanking sequences of double-copy gene is a challenge in molecular biology. We developed a method to solve this problem by combining an optimized inverse PCR (iPCR) with TAIL-PCR. First, Southern blotting analysis was used to determine a proper restriction enzyme that could obtain proper-length restriction fragments that contained the target gene. Then optimized iPCR was performed to amplify the restriction fragments that contained the separated copies of the gene. Based on the obtained sequences, TAIL-PCR was performed to amplify further flanking regions of the gene. With this method, we obtained all of the EcoR I restriction fragments (2.2-5.1 kb) and Hind III restriction fragments (8.5-11.7 kb) of mitochondrial atpA gene in cytoplasmic male sterile (CMS) line and maintainer line of Upland cotton. The results showed that this method was an efficient approach to clone flanking sequences of double-copy gene.
Chromosome Walking ; Cloning, Molecular ; Gene Expression Regulation, Plant ; Genes, Mitochondrial ; Genes, Plant ; genetics ; Gossypium ; genetics ; Plant Proteins ; genetics ; metabolism ; Polymerase Chain Reaction ; methods ; Terminal Repeat Sequences