Intestinal homeostasis is maintained by specialized host cells and the gut microbiota.Wnt/β-catenin signaling is essential for gastrointestinal development and homeostasis,and its dysregulation has been implicated in...Intestinal homeostasis is maintained by specialized host cells and the gut microbiota.Wnt/β-catenin signaling is essential for gastrointestinal development and homeostasis,and its dysregulation has been implicated in inflammation and colorectal cancer.Axin1 negatively regulates activated Wnt/β-catenin signaling,but little is known regarding its role in regulating host–microbial interactions in health and disease.Here,we aim to demonstrate that intestinal Axin1 determines gut homeostasis and host response to inflammation.Axin1 expression was analyzed in human inflammatory bowel disease datasets.To explore the effects and mechanism of intestinal Axin1 in regulating intestinal homeostasis and colitis,we generated new mouse models with Axin1 conditional knockout in intestinal epithelial cell(IEC;Axin1^(ΔIEC))and Paneth cell(PC;Axin1^(ΔPC))to compare with control(Axin1^(LoxP);LoxP:locus of X-over,P1)mice.We found increased Axin1 expression in the colonic epithelium of human inflammatory bowel disease(IBD).Axin1^(ΔIEC) mice exhibited altered goblet cell spatial distribution,PC morphology,reduced lysozyme expression,and enriched Akkermansia muciniphila(A.muciniphila).The absence of intestinal epithelial and PC Axin1 decreased susceptibility to dextran sulfate sodium(DSS)-induced colitis in vivo.Axin1^(ΔIEC) and Axin1^(ΔPC)mice became more susceptible to DSS-colitis after cohousing with control mice.Treatment with A.muciniphila reduced DSS-colitis severity.Antibiotic treatment did not change the IEC proliferation in the Axin1Loxp mice.However,the intestinal proliferative cells in Axin1^(ΔIEC)mice with antibiotic treatment were reduced compared with those in Axin1^(ΔIEC) mice without treatment.These data suggest non-colitogenic effects driven by the gut microbiome.In conclusion,we found that the loss of intestinal Axin1 protects against colitis,likely driven by epithelial Axin1 and Axin1-associated A.muciniphila.Our study demonstrates a novel role of Axin1 in mediating intestinal homeostasis and the microbiota.Further mechanistic studies using specific Axin1 mutations elucidating how Axin1 modulates the microbiome and host inflammatory response will provide new therapeutic strategies for human IBD.展开更多
Background:Metformin has pleiotropic effects beyond glucose reduction,including tumor inhibition and immune regulation.It enhanced the anti-tumor effects of programmed cell death protein 1(PD-1)inhibitors in serine/th...Background:Metformin has pleiotropic effects beyond glucose reduction,including tumor inhibition and immune regulation.It enhanced the anti-tumor effects of programmed cell death protein 1(PD-1)inhibitors in serine/threonine kinase 11(STK11)mutant non-small cell lung cancer(NSCLC)through an axis inhibition protein 1(AXIN1)-dependent manner.However,the alterations of tumor metabolism and metabolites upon metformin administration remain unclear.Methods:We performed untargeted metabolomics using liquid chromatography(LC)-mass spectrometry(MS)/MS system and conducted cell experiments to verify the results of bioinformatics analysis.Results:According to the Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway database,most metabolites were annotated into metabolism,including nucleotide metabolism.Next,the differentially expressed metabolites in H460(refers to H460 cells),H460_met(refers to metformin-treated H460 cells),and H460_KO_met(refers to metformin-treated Axin1-/-H460 cells)were distributed into six clusters based on expression patterns.The clusters with a reversed expression pattern upon metformin treatment were selected for further analysis.We screened out metabolic pathways through KEGG pathway enrichment analysis and found that multiple nucleotide metabolites enriched in this pathway were upregulated.Furthermore,these metabolites enhanced the cytotoxicity of activated T cells on H460 cells in vitro and can activate the stimulator of the interferon genes(STING)pathway independently of AXIN1.Conclusion:Relying on AXIN1,metformin upregulated multiple nucleotide metabolites which promoted STING signaling and the killing of activated T cells in STK11 mutant NSCLC,indicating a potential immunotherapeutic strategy for STK11 mutant NSCLC.展开更多
AIM: To explore the contribution of AXIN1, AXIN2 and beta-catenin, components of Wnt signaling pathway, to the carcinogenesis of gastric cancer (GC), we examined AXIN1, AXIN2 exon7 and CTNNB1 (encoding beta- catenin) ...AIM: To explore the contribution of AXIN1, AXIN2 and beta-catenin, components of Wnt signaling pathway, to the carcinogenesis of gastric cancer (GC), we examined AXIN1, AXIN2 exon7 and CTNNB1 (encoding beta- catenin) exon3 mutations in 70 GCs. METHODS: The presence of mutations was identified by polymerase chain reaction (PCR)-based denaturing high-performance liquid chromatography and direct DNA sequencing. Beta-catenin expression was detected by immunohistochemical analysis. RESULTS: Among the 70 GCs, 5 (7.1%) had mutations in one or two of these three components. A frameshift mutation (1 bp deletion) in exon7 of AXIN2 was found in one case. Four cases, including the case with a mutation in AXIN2, had frameshift mutations and missense mutations in AXIN1. Five single nucleotide polymorphisms (SNPs), 334 C>T, 874 C>T, 1396 G>A, 1690 C>T and 1942 T>G, were identified in AXIN1. A frameshift mutation (27 bp deletion) spanning exon3 of CTNNB1 was observed in one case. All four cases with mutations in AXIN1 and AXIN2 showed nuclear beta- catenin expression. CONCLUSION: These data indicate that the mutationsin AXIN1 and AXIN2 may contribute to gastric carcino- genesis.展开更多
基金the VA Merit Award(1 I01BX004824-01)the National Institute of Diabetes and Digestive and Kidney Diseases/National Institutes of Health Grants(R01 DK105118 and R01DK114126)the Crohn’s&Colitis Foundation Senior Research Award(902766)to Jun Sun.
文摘Intestinal homeostasis is maintained by specialized host cells and the gut microbiota.Wnt/β-catenin signaling is essential for gastrointestinal development and homeostasis,and its dysregulation has been implicated in inflammation and colorectal cancer.Axin1 negatively regulates activated Wnt/β-catenin signaling,but little is known regarding its role in regulating host–microbial interactions in health and disease.Here,we aim to demonstrate that intestinal Axin1 determines gut homeostasis and host response to inflammation.Axin1 expression was analyzed in human inflammatory bowel disease datasets.To explore the effects and mechanism of intestinal Axin1 in regulating intestinal homeostasis and colitis,we generated new mouse models with Axin1 conditional knockout in intestinal epithelial cell(IEC;Axin1^(ΔIEC))and Paneth cell(PC;Axin1^(ΔPC))to compare with control(Axin1^(LoxP);LoxP:locus of X-over,P1)mice.We found increased Axin1 expression in the colonic epithelium of human inflammatory bowel disease(IBD).Axin1^(ΔIEC) mice exhibited altered goblet cell spatial distribution,PC morphology,reduced lysozyme expression,and enriched Akkermansia muciniphila(A.muciniphila).The absence of intestinal epithelial and PC Axin1 decreased susceptibility to dextran sulfate sodium(DSS)-induced colitis in vivo.Axin1^(ΔIEC) and Axin1^(ΔPC)mice became more susceptible to DSS-colitis after cohousing with control mice.Treatment with A.muciniphila reduced DSS-colitis severity.Antibiotic treatment did not change the IEC proliferation in the Axin1Loxp mice.However,the intestinal proliferative cells in Axin1^(ΔIEC)mice with antibiotic treatment were reduced compared with those in Axin1^(ΔIEC) mice without treatment.These data suggest non-colitogenic effects driven by the gut microbiome.In conclusion,we found that the loss of intestinal Axin1 protects against colitis,likely driven by epithelial Axin1 and Axin1-associated A.muciniphila.Our study demonstrates a novel role of Axin1 in mediating intestinal homeostasis and the microbiota.Further mechanistic studies using specific Axin1 mutations elucidating how Axin1 modulates the microbiome and host inflammatory response will provide new therapeutic strategies for human IBD.
基金People’s Hospital of Xuyong County-Southwest Medical University Science and Technology Strategic Cooperation Project(2023XYXNYD05)Guangdong Association of Clinical Trials(GACT)/Chinese Thoracic Oncology Group(CTONG)and Guangdong Provincial Key Lab of Translational Medicine in Lung Cancer(2017B030314120)Natural Science Foundation of Chongqing Municipality(CSTB2023NSCQ-MSX0554).
文摘Background:Metformin has pleiotropic effects beyond glucose reduction,including tumor inhibition and immune regulation.It enhanced the anti-tumor effects of programmed cell death protein 1(PD-1)inhibitors in serine/threonine kinase 11(STK11)mutant non-small cell lung cancer(NSCLC)through an axis inhibition protein 1(AXIN1)-dependent manner.However,the alterations of tumor metabolism and metabolites upon metformin administration remain unclear.Methods:We performed untargeted metabolomics using liquid chromatography(LC)-mass spectrometry(MS)/MS system and conducted cell experiments to verify the results of bioinformatics analysis.Results:According to the Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway database,most metabolites were annotated into metabolism,including nucleotide metabolism.Next,the differentially expressed metabolites in H460(refers to H460 cells),H460_met(refers to metformin-treated H460 cells),and H460_KO_met(refers to metformin-treated Axin1-/-H460 cells)were distributed into six clusters based on expression patterns.The clusters with a reversed expression pattern upon metformin treatment were selected for further analysis.We screened out metabolic pathways through KEGG pathway enrichment analysis and found that multiple nucleotide metabolites enriched in this pathway were upregulated.Furthermore,these metabolites enhanced the cytotoxicity of activated T cells on H460 cells in vitro and can activate the stimulator of the interferon genes(STING)pathway independently of AXIN1.Conclusion:Relying on AXIN1,metformin upregulated multiple nucleotide metabolites which promoted STING signaling and the killing of activated T cells in STK11 mutant NSCLC,indicating a potential immunotherapeutic strategy for STK11 mutant NSCLC.
文摘AIM: To explore the contribution of AXIN1, AXIN2 and beta-catenin, components of Wnt signaling pathway, to the carcinogenesis of gastric cancer (GC), we examined AXIN1, AXIN2 exon7 and CTNNB1 (encoding beta- catenin) exon3 mutations in 70 GCs. METHODS: The presence of mutations was identified by polymerase chain reaction (PCR)-based denaturing high-performance liquid chromatography and direct DNA sequencing. Beta-catenin expression was detected by immunohistochemical analysis. RESULTS: Among the 70 GCs, 5 (7.1%) had mutations in one or two of these three components. A frameshift mutation (1 bp deletion) in exon7 of AXIN2 was found in one case. Four cases, including the case with a mutation in AXIN2, had frameshift mutations and missense mutations in AXIN1. Five single nucleotide polymorphisms (SNPs), 334 C>T, 874 C>T, 1396 G>A, 1690 C>T and 1942 T>G, were identified in AXIN1. A frameshift mutation (27 bp deletion) spanning exon3 of CTNNB1 was observed in one case. All four cases with mutations in AXIN1 and AXIN2 showed nuclear beta- catenin expression. CONCLUSION: These data indicate that the mutationsin AXIN1 and AXIN2 may contribute to gastric carcino- genesis.
