The amyloid aggregation of peptides and proteins is a hallmark of neurological disorders and type 2 diabetes.Human islet amyloid polypeptide(IAPP),co-secreted with insulin by pancreaticβ-cells,plays dual roles in bot...The amyloid aggregation of peptides and proteins is a hallmark of neurological disorders and type 2 diabetes.Human islet amyloid polypeptide(IAPP),co-secreted with insulin by pancreaticβ-cells,plays dual roles in both glycemic control and the pathology of type 2 diabetes.While IAPP can activate the NLRP3 inflammasome and modulate cellular autophagy,apoptosis and extracellular matrix metabolism,no data is available concerning intracellular protein expression upon exposure to the polypeptide.More surprisingly,how intracellular protein expression is modulated by nanoparticle inhibitors of protein aggregation remains entirely unknown.In this study,we first examined the changing proteomes ofβTC6,a pancreaticβ-cell line,upon exposure to monomeric,oligomeric and fibrillar IAPP,and detailed cellular protein expression rescued by graphene quantum dots(GQDs),an IAPP inhibitor.We found that 29 proteins were significantly dysregulated by the IAPP species,while majority of these proteins were nucleotide-binding proteins.Collectively,our liquid chromatography tandem-mass spectrometry,fluorescence quenching,helium ion microscopy,cytotoxicity and discreet molecular dynamics simulations data revealed a remarkable capacity of GQDs in regulating aberrant protein expression through H-bonding and hydrophobic interactions,pointing to nanomedicine as a new frontier against human amyloid diseases.展开更多
Although much has been learned about the fibrillization kinetics, structure and toxicity of amyloid proteins, the properties of amyloid fibrils beyond the saturation phase are often perceived as chemically and biologi...Although much has been learned about the fibrillization kinetics, structure and toxicity of amyloid proteins, the properties of amyloid fibrils beyond the saturation phase are often perceived as chemically and biologically inert, despite evidence suggesting otherwise. To fill this knowledge gap, we examined the physical and biological characteristics of human islet amyloid polypeptide(IAPP) fibrils that were aged up to two months. Not only did aging decrease the toxicity of IAPP fibrils, but the fibrils also sequestered fresh IAPP and suppressed their toxicity in an embryonic zebrafish model. The mechanical properties of IAPP fibrils in different aging stages were probed by atomic force microscopy and sonication, which displayed comparable stiffness but age-dependent fragmentation, followed by self-assembly of such fragments into the largest lamellar amyloid structures reported to date. The dynamic structural and toxicity profiles of amyloid fibrils and plaques suggest that they play active, long-term roles in cell degeneration and may be a therapeutic target for amyloid diseases.展开更多
基金This work was conceived by PCK,and was by supported by ARC Project No.CE140100036(Davis),NSF CAREER CBET-1553945(Ding),NIH MIRA R35GM119691(Ding),AFTAM Research Collaboration Award(Davis and Ke),the National Natural Science Foundation of China(No.11904189)(Sun)the Juvenile Diabetes Research Foundation(Purcell and Faridi).A.W.P.is supported by a Principal Research Fellowship from the Australian NHMRC.TEM imaging was performed at Bio21 Advanced Microscopy Facility,University of Melbourne.HIM imaging was performed at the MCFP platform,University of Melbourne by Dr.Anders Barlow.
文摘The amyloid aggregation of peptides and proteins is a hallmark of neurological disorders and type 2 diabetes.Human islet amyloid polypeptide(IAPP),co-secreted with insulin by pancreaticβ-cells,plays dual roles in both glycemic control and the pathology of type 2 diabetes.While IAPP can activate the NLRP3 inflammasome and modulate cellular autophagy,apoptosis and extracellular matrix metabolism,no data is available concerning intracellular protein expression upon exposure to the polypeptide.More surprisingly,how intracellular protein expression is modulated by nanoparticle inhibitors of protein aggregation remains entirely unknown.In this study,we first examined the changing proteomes ofβTC6,a pancreaticβ-cell line,upon exposure to monomeric,oligomeric and fibrillar IAPP,and detailed cellular protein expression rescued by graphene quantum dots(GQDs),an IAPP inhibitor.We found that 29 proteins were significantly dysregulated by the IAPP species,while majority of these proteins were nucleotide-binding proteins.Collectively,our liquid chromatography tandem-mass spectrometry,fluorescence quenching,helium ion microscopy,cytotoxicity and discreet molecular dynamics simulations data revealed a remarkable capacity of GQDs in regulating aberrant protein expression through H-bonding and hydrophobic interactions,pointing to nanomedicine as a new frontier against human amyloid diseases.
基金supported by ARC Project CE140100036 (Davis), NSF CAREER CBET-1553945 (Ding), NIH MIRA R35GM119691 (Ding) and Monash Institute of Pharmaceutical Sciences (Ke) Purcell is supported by a Principal Research Fellowship from the Australian NHMRC+1 种基金Pilkington acknowledges an Australian Government Research Training Program (RTP) ScholarshipJaved acknowledges Monash International Postgraduate Research Scholarship
文摘Although much has been learned about the fibrillization kinetics, structure and toxicity of amyloid proteins, the properties of amyloid fibrils beyond the saturation phase are often perceived as chemically and biologically inert, despite evidence suggesting otherwise. To fill this knowledge gap, we examined the physical and biological characteristics of human islet amyloid polypeptide(IAPP) fibrils that were aged up to two months. Not only did aging decrease the toxicity of IAPP fibrils, but the fibrils also sequestered fresh IAPP and suppressed their toxicity in an embryonic zebrafish model. The mechanical properties of IAPP fibrils in different aging stages were probed by atomic force microscopy and sonication, which displayed comparable stiffness but age-dependent fragmentation, followed by self-assembly of such fragments into the largest lamellar amyloid structures reported to date. The dynamic structural and toxicity profiles of amyloid fibrils and plaques suggest that they play active, long-term roles in cell degeneration and may be a therapeutic target for amyloid diseases.
