BACKGROUND Deoxycholic acid(DCA),a secondary bile acid,is associated with colorectal carcinogenesis,but its mechanisms remain unclear.AIM To investigate how DCA regulates apoptosis in colorectal cancer(CRC)cells.METHO...BACKGROUND Deoxycholic acid(DCA),a secondary bile acid,is associated with colorectal carcinogenesis,but its mechanisms remain unclear.AIM To investigate how DCA regulates apoptosis in colorectal cancer(CRC)cells.METHODS SW480 and DLD-1 CRC cell lines were used to investigate the mechanism of apoptosis by western blotting,flow cytometry,confocal microscopy,and other methods.RESULTS DCA significantly induced apoptosis,with rates increasing to 7.2%±1.5%in SW480 cells and 14.3%±0.6%in DLD-1 cells after treatment,compared to 4.7%±1.0%and 11.6%±0.8%in controls(P<0.05).Western blot analysis showed upregulation of pro-apoptotic proteins Bax and Cleaved-PARP,with a significant increase in the Cleaved-PARP/PARP ratio(P<0.001).DCA treatment also increased the intracellular reactive oxygen species(ROS)levels of SW480 and DLD-1 cells to 1.2-fold and 1.3-fold,respectively(P<0.01),while the increase of mitochondrial ROS levels in these cells was statistically significant under confocal microscopy.Additionally,cytosolic and mitochondrial Ca^(2+)levels increased 1.3-fold and 1.2-fold,respectively,in SW480 cells(P<0.01),and 1.1-fold and 1.1-fold,respectively,in DLD-1 cells compared with controls(P<0.05).p-CaMKII protein levels were also elevated(P<0.01),indicating activation of the Ca^(2+)-CaMKII signaling pathway.Pharmacological inhibition with BAPTAAM(1μM)reduced mitochondrial Ca^(2+)accumulation and ROS levels in SW480 cells(P<0.05),and suppressed apoptosis.CONCLUSION DCA activates the Ca^(2+)-CaMKII pathway,leading to ROS-mediated apoptosis in CRC cells,providing insights for potential therapeutic targets.展开更多
The proper differentiation and reorganization of the intestinal epithelial cell population is critical to mucosal regeneration post injury.Label retaining cells(LRCs)expressing SRY-box transcription factor 9(SOX9)prom...The proper differentiation and reorganization of the intestinal epithelial cell population is critical to mucosal regeneration post injury.Label retaining cells(LRCs)expressing SRY-box transcription factor 9(SOX9)promote epithelial repair by replenishing LGR5 t intestinal stem cells(ISCs).While,LRCs are also considered precursor cells for enteroendocrine cells(EECs)which exacerbate mucosal damage in inflammatory bowel disease(IBD).The factors that determine LRC-EEC differentiation and the effect of intervening in LRC-EEC differentiation on IBD remain unclear.In this study,we investigated the effects of a natural anthraquinone called aloe emodin(derived from the Chinese herb rhubarb)on mucosal healing in IBD models.Our findings demonstrated that aloe emodin effectively interfered with the differentiation to EECs and preserved a higher number of SOX9t LRCs,thereby promoting mucosal healing.Furthermore,we discovered that aloe emodin acted as an antagonist of free fatty acid receptors(FFAR1),suppressing the FFAR1-mediated Gbg/serine/threonine-protein kinase(AKT)pathway and promoting the translocation of forkhead box protein O1(FOXO1)into the nucleus,ultimately resulting in the intervention of differentiation fate.These findings reveal the effect of free fatty acid accessibility on EEC differentiation and introduce a strategy for promoting mucosal healing in IBD by regulating the FFAR1/AKT/FOXO1 signaling pathway.展开更多
Background:Lgr5-positive cells located in the basal layer of crypts have self-regenerative and proliferative differentiation potentials of intestinal stem cells(ISCs),maintaining a balance of regeneration-repair in mu...Background:Lgr5-positive cells located in the basal layer of crypts have self-regenerative and proliferative differentiation potentials of intestinal stem cells(ISCs),maintaining a balance of regeneration-repair in mucosal epithelium.However,the mechanisms of mucosal repair that are regulated by ISCs in ulcerative colitis(UC)remain unclear.Method:Colon tissues from patients with UC were collected to testβ-catenin and Notch1 expression by using Western blot and quantitative real-time polymerase chain reaction(PCR).β-catenin^(fl/fl) mice,β-cateninTg mice,and Dll1tm1 Gos mice were used to cross with Lgr5-EGFP-IRES-creERT2 mice to generate mice of different genotypes,altering the activation of Wnt/β-catenin and Dll1-mediated Notch signaling in ISCs in vivo.Dextran sulfate sodium(DSS)was used to induce a colitis mice model.Intestinal organoids were isolated and cultured to observe the proliferation and differentiation levels of ISCs.Result:β-catenin and Notch1 expression were significantly increased in the inflamed colon tissues from patients with UC.Wnt/β-catenin activation and Dll1-mediated Notch pathway inhibition in Lgr5-positive stem cells promoted the expressions of E-cadherin,CK20,and CHGA in colonic organoids and epithelium,implying the promotion of colonic epithelial integrity.Activation of Wnt/β-catenin and suppression of Dll1-mediated Notch pathway in Lgr5-positive ISCs alleviated the DSS-induced intestinal mucosal inflammation in mice.Conclusions:Lgr5-positive ISCs are characterized by self-renewal and high dividend potential,which play an important role in the injury and repair of intestinal mucosa.More importantly,the Wnt/β-catenin signaling pathway cooperates with the Notch signaling pathway to maintain the function of the Lgr5-positive ISCs.展开更多
基金Supported by the Key Discipline of Zhejiang Province in Medical Technology(First Class,Category A)Wenzhou Science&Technological Project,No.Y20240103.
文摘BACKGROUND Deoxycholic acid(DCA),a secondary bile acid,is associated with colorectal carcinogenesis,but its mechanisms remain unclear.AIM To investigate how DCA regulates apoptosis in colorectal cancer(CRC)cells.METHODS SW480 and DLD-1 CRC cell lines were used to investigate the mechanism of apoptosis by western blotting,flow cytometry,confocal microscopy,and other methods.RESULTS DCA significantly induced apoptosis,with rates increasing to 7.2%±1.5%in SW480 cells and 14.3%±0.6%in DLD-1 cells after treatment,compared to 4.7%±1.0%and 11.6%±0.8%in controls(P<0.05).Western blot analysis showed upregulation of pro-apoptotic proteins Bax and Cleaved-PARP,with a significant increase in the Cleaved-PARP/PARP ratio(P<0.001).DCA treatment also increased the intracellular reactive oxygen species(ROS)levels of SW480 and DLD-1 cells to 1.2-fold and 1.3-fold,respectively(P<0.01),while the increase of mitochondrial ROS levels in these cells was statistically significant under confocal microscopy.Additionally,cytosolic and mitochondrial Ca^(2+)levels increased 1.3-fold and 1.2-fold,respectively,in SW480 cells(P<0.01),and 1.1-fold and 1.1-fold,respectively,in DLD-1 cells compared with controls(P<0.05).p-CaMKII protein levels were also elevated(P<0.01),indicating activation of the Ca^(2+)-CaMKII signaling pathway.Pharmacological inhibition with BAPTAAM(1μM)reduced mitochondrial Ca^(2+)accumulation and ROS levels in SW480 cells(P<0.05),and suppressed apoptosis.CONCLUSION DCA activates the Ca^(2+)-CaMKII pathway,leading to ROS-mediated apoptosis in CRC cells,providing insights for potential therapeutic targets.
基金National Natural Science Foundation of China(Nos.82030113,82130108,and 82204717)China Postdoctoral Science Foundation(Nos.BX20220069 and 2021M700864).
文摘The proper differentiation and reorganization of the intestinal epithelial cell population is critical to mucosal regeneration post injury.Label retaining cells(LRCs)expressing SRY-box transcription factor 9(SOX9)promote epithelial repair by replenishing LGR5 t intestinal stem cells(ISCs).While,LRCs are also considered precursor cells for enteroendocrine cells(EECs)which exacerbate mucosal damage in inflammatory bowel disease(IBD).The factors that determine LRC-EEC differentiation and the effect of intervening in LRC-EEC differentiation on IBD remain unclear.In this study,we investigated the effects of a natural anthraquinone called aloe emodin(derived from the Chinese herb rhubarb)on mucosal healing in IBD models.Our findings demonstrated that aloe emodin effectively interfered with the differentiation to EECs and preserved a higher number of SOX9t LRCs,thereby promoting mucosal healing.Furthermore,we discovered that aloe emodin acted as an antagonist of free fatty acid receptors(FFAR1),suppressing the FFAR1-mediated Gbg/serine/threonine-protein kinase(AKT)pathway and promoting the translocation of forkhead box protein O1(FOXO1)into the nucleus,ultimately resulting in the intervention of differentiation fate.These findings reveal the effect of free fatty acid accessibility on EEC differentiation and introduce a strategy for promoting mucosal healing in IBD by regulating the FFAR1/AKT/FOXO1 signaling pathway.
基金supported by the National Natural Science Foundation of China[No.82000481,81570474,and 82270549].
文摘Background:Lgr5-positive cells located in the basal layer of crypts have self-regenerative and proliferative differentiation potentials of intestinal stem cells(ISCs),maintaining a balance of regeneration-repair in mucosal epithelium.However,the mechanisms of mucosal repair that are regulated by ISCs in ulcerative colitis(UC)remain unclear.Method:Colon tissues from patients with UC were collected to testβ-catenin and Notch1 expression by using Western blot and quantitative real-time polymerase chain reaction(PCR).β-catenin^(fl/fl) mice,β-cateninTg mice,and Dll1tm1 Gos mice were used to cross with Lgr5-EGFP-IRES-creERT2 mice to generate mice of different genotypes,altering the activation of Wnt/β-catenin and Dll1-mediated Notch signaling in ISCs in vivo.Dextran sulfate sodium(DSS)was used to induce a colitis mice model.Intestinal organoids were isolated and cultured to observe the proliferation and differentiation levels of ISCs.Result:β-catenin and Notch1 expression were significantly increased in the inflamed colon tissues from patients with UC.Wnt/β-catenin activation and Dll1-mediated Notch pathway inhibition in Lgr5-positive stem cells promoted the expressions of E-cadherin,CK20,and CHGA in colonic organoids and epithelium,implying the promotion of colonic epithelial integrity.Activation of Wnt/β-catenin and suppression of Dll1-mediated Notch pathway in Lgr5-positive ISCs alleviated the DSS-induced intestinal mucosal inflammation in mice.Conclusions:Lgr5-positive ISCs are characterized by self-renewal and high dividend potential,which play an important role in the injury and repair of intestinal mucosa.More importantly,the Wnt/β-catenin signaling pathway cooperates with the Notch signaling pathway to maintain the function of the Lgr5-positive ISCs.
