Autophagy plays a pivotal role in diverse biological processes,including the maintenance and differentiation of neural stem cells(NSCs).Interestingly,while complete deletion of Fip200 severely impairs NSC maintenance ...Autophagy plays a pivotal role in diverse biological processes,including the maintenance and differentiation of neural stem cells(NSCs).Interestingly,while complete deletion of Fip200 severely impairs NSC maintenance and differentiation,inhibiting canonical autophagy via deletion of core genes,such as Atg5,Atg16l1,and Atg7,or blockade of canonical interactions between FIP200 and ATG13(designated as FIP200-4A mutant or FIP200 KI)does not produce comparable detrimental effects.This highlights the likely critical involvement of the non-canonical functions of FIP200,the mechanisms of which have remained elusive.Here,utilizing genetic mouse models,we demonstrated that FIP200 mediates non-canonical autophagic degradation of p62/sequestome1,primarily via TAX1BP1 in NSCs.Conditional deletion of Tax1bp1 in fip200hGFAP conditional knock-in(cKI)mice led to NSC deficiency,resembling the fip200hGFAP conditional knockout(cKO)mouse phenotype.Notably,reintroducing wild-type TAX1BP1 not only restored the maintenance of NSCs derived from tax1bp1-knockout fip200hGFAP cKI mice but also led to a marked reduction in p62 aggregate accumulation.Conversely,a TAX1BP1 mutant incapable of binding to FIP200 or NBR1/p62 failed to achieve this restoration.Furthermore,conditional deletion of Tax1bp1 in fip200hGFAP cKO mice exacerbated NSC deficiency and p62 aggregate accumulation compared to fip200hGFAP cKO mice.Collectively,these findings illustrate the essential role of the FIP200-TAX1BP1 axis in mediating the non-canonical autophagic degradation of p62 aggregates towards NSC maintenance and function,presenting novel therapeutic targets for neurodegenerative diseases.展开更多
BACKGROUND Necroptosis has emerged as a novel molecular pathway that can be targeted by chemotherapy agents in the treatment of cancer.OSW-1,which is derived from the bulbs of Ornithogalum saundersiae Baker,exerts a w...BACKGROUND Necroptosis has emerged as a novel molecular pathway that can be targeted by chemotherapy agents in the treatment of cancer.OSW-1,which is derived from the bulbs of Ornithogalum saundersiae Baker,exerts a wide range of pharmaco-logical effects.AIM To explore whether OSW-1 can induce necroptosis in colorectal cancer(CRC)cells,thereby expanding its range of clinical applications.METHODS We performed a sequence of functional experiments,including Cell Counting Kit-8 assays and flow cytometry analysis,to assess the inhibitory effect of OSW-1 on CRC cells.We utilized quantitative proteomics,employing tandem mass tag label-ing combined with liquid chromatography-tandem mass spectrometry,to analyze changes in protein expression.Subsequent bioinformatic analysis was conducted to elucidate the biological processes associated with the identified proteins.Transmission electron microscopy(TEM)and immunofluorescence studies were also performed to examine the effects of OSW-1 on necroptosis.Finally,western blotting,siRNA experiments,and immunoprecipitation were employed to evaluate protein interactions within CRC cells.RESULTS The results revealed that OSW-1 exerted a strong inhibitory effect on CRC cells,and this effect was accompanied by a necroptosis-like morphology that was observable via TEM.OSW-1 was shown to trigger necroptosis via activation of the RIPK1/RIPK3/MLKL pathway.Furthermore,the accumulation of p62/SQSTM1 was shown to mediate OSW-1-induced necroptosis through its interaction with RIPK1.CONCLUSION We propose that OSW-1 can induce necroptosis through the RIPK1/RIPK3/MLKL signaling pathway,and that this effect is mediated by the RIPK1-p62/SQSTM1 complex,in CRC cells.These results provide a theoretical foundation for the use of OSW-1 in the clinical treatment of CRC.展开更多
基金National Natural Science Foundation of China(U2004138,81773132,81820108021)University Excellent Teaching Team of“Qinglan Project”in Jiangsu Province(2022-25)+1 种基金Henan Province Key Research and Development Project(232102521028)Excellent Youth Foundation of Henan Scientific Committee(21230040016)。
文摘Autophagy plays a pivotal role in diverse biological processes,including the maintenance and differentiation of neural stem cells(NSCs).Interestingly,while complete deletion of Fip200 severely impairs NSC maintenance and differentiation,inhibiting canonical autophagy via deletion of core genes,such as Atg5,Atg16l1,and Atg7,or blockade of canonical interactions between FIP200 and ATG13(designated as FIP200-4A mutant or FIP200 KI)does not produce comparable detrimental effects.This highlights the likely critical involvement of the non-canonical functions of FIP200,the mechanisms of which have remained elusive.Here,utilizing genetic mouse models,we demonstrated that FIP200 mediates non-canonical autophagic degradation of p62/sequestome1,primarily via TAX1BP1 in NSCs.Conditional deletion of Tax1bp1 in fip200hGFAP conditional knock-in(cKI)mice led to NSC deficiency,resembling the fip200hGFAP conditional knockout(cKO)mouse phenotype.Notably,reintroducing wild-type TAX1BP1 not only restored the maintenance of NSCs derived from tax1bp1-knockout fip200hGFAP cKI mice but also led to a marked reduction in p62 aggregate accumulation.Conversely,a TAX1BP1 mutant incapable of binding to FIP200 or NBR1/p62 failed to achieve this restoration.Furthermore,conditional deletion of Tax1bp1 in fip200hGFAP cKO mice exacerbated NSC deficiency and p62 aggregate accumulation compared to fip200hGFAP cKO mice.Collectively,these findings illustrate the essential role of the FIP200-TAX1BP1 axis in mediating the non-canonical autophagic degradation of p62 aggregates towards NSC maintenance and function,presenting novel therapeutic targets for neurodegenerative diseases.
基金Supported by the Natural Science Foundation of Liaoning Province,No.2022-MS-330and Key Projects in Liaoning Province,No.2020JH2/10300046.
文摘BACKGROUND Necroptosis has emerged as a novel molecular pathway that can be targeted by chemotherapy agents in the treatment of cancer.OSW-1,which is derived from the bulbs of Ornithogalum saundersiae Baker,exerts a wide range of pharmaco-logical effects.AIM To explore whether OSW-1 can induce necroptosis in colorectal cancer(CRC)cells,thereby expanding its range of clinical applications.METHODS We performed a sequence of functional experiments,including Cell Counting Kit-8 assays and flow cytometry analysis,to assess the inhibitory effect of OSW-1 on CRC cells.We utilized quantitative proteomics,employing tandem mass tag label-ing combined with liquid chromatography-tandem mass spectrometry,to analyze changes in protein expression.Subsequent bioinformatic analysis was conducted to elucidate the biological processes associated with the identified proteins.Transmission electron microscopy(TEM)and immunofluorescence studies were also performed to examine the effects of OSW-1 on necroptosis.Finally,western blotting,siRNA experiments,and immunoprecipitation were employed to evaluate protein interactions within CRC cells.RESULTS The results revealed that OSW-1 exerted a strong inhibitory effect on CRC cells,and this effect was accompanied by a necroptosis-like morphology that was observable via TEM.OSW-1 was shown to trigger necroptosis via activation of the RIPK1/RIPK3/MLKL pathway.Furthermore,the accumulation of p62/SQSTM1 was shown to mediate OSW-1-induced necroptosis through its interaction with RIPK1.CONCLUSION We propose that OSW-1 can induce necroptosis through the RIPK1/RIPK3/MLKL signaling pathway,and that this effect is mediated by the RIPK1-p62/SQSTM1 complex,in CRC cells.These results provide a theoretical foundation for the use of OSW-1 in the clinical treatment of CRC.
