Prion diseases are a class of fatal neurodegenerative diseases caused by misfolded prion proteins.The main reason is that pathogenic prion protein has a strong tendency to aggregate,which easily induces the damage to ...Prion diseases are a class of fatal neurodegenerative diseases caused by misfolded prion proteins.The main reason is that pathogenic prion protein has a strong tendency to aggregate,which easily induces the damage to the central nervous system.Point mutations in the human prion protein gene can cause prion diseases such as Creutzfeldt-Jakob and Gerstmann's syndrome.To understand the mechanism of mutation-induced prion protein aggregation,the mutants in an aqueous solution are studied by molecular dynamics simulations,including the wild type,V180I,H187R and a double point mutation which is associated with CJD and GSS.After running simulations for 500 ns,the results show that these three mutations have different effects on the kinetic properties of PrP.The high fluctuations around the N-terminal residues of helix 2 in the V180I variant lead to a decrease in hydrogen bonding on helix 2,while an increase in the number of hydrogen bonds between the folded regions promotes the generation ofβ-sheet.Meanwhile,partial deletion of salt bridges in the H187R and double mutants allows the sub-structural domains of the prion protein to separate,which would accelerate the conversion from PrPC to PrPSc.A similar trend is observed in both SASA and Rg for all three mutations,indicating that the conformational space is reduced and the structure is compact.展开更多
Prions are infectious conformations of certain naturally occurring proteins.These misfolded proteins can structurally alter healthy protein,creating misfolded copies that repeat the process and form protein aggr...Prions are infectious conformations of certain naturally occurring proteins.These misfolded proteins can structurally alter healthy protein,creating misfolded copies that repeat the process and form protein aggregates that lead to neuronal cell death.Although years can pass from initial prion infection to clinical presentation of symptoms,onset of symptoms is typically followed by rapid neurological decline resulting in death.Prion diseases have been characterized in animals ranging from sheep and cattle to cervids and humans,with notable cross-species infections such as the variant Creutzfeldt-Jakob disease.Thus,prions present a health risk with the potential to disrupt major food sources as well affect human health through animal to human and human to human transmission events.While human to human prion transmission is rare and the immediate risks for a prion-facilitated pandemic are low,prions are a class of pathogens for which we are underprepared.In addition,prions,and prion disease-like approaches,have also been discussed in the context of biological weapons and toxins,adding another layer of complexity surrounding biosecurity and biodefense.These threats underscore the need for increased scrutiny and research on prions.Here,pharmaceutical and nonpharmaceutical prion-specific interventions are discussed.Recent advances in prion therapeutic development are also briefly highlighted,and a set of policy recommendations are given that aims to provide high level suggestions for the prevention and mitigation of prion diseases.展开更多
Prion diseases are infectious protein misfolding disorders of the central nervous system that result from misfolding of the cellular prion protein(PrPC)into the pathologic isoform PrPSc.Pathologic hallmarks of prion d...Prion diseases are infectious protein misfolding disorders of the central nervous system that result from misfolding of the cellular prion protein(PrPC)into the pathologic isoform PrPSc.Pathologic hallmarks of prion disease are depositions of pathological prion protein PrPSc,neuronal loss,spongiform degeneration and astrogliosis in the brain.Prion diseases affect human and animals,there is no effective therapy,and they invariably remain fatal.For a long time,neuronal loss was considered the sole reason for neurodegeneration in prion pathogenesis,and the contribution of non-neuronal cells like microglia and astrocytes was considered less important.Recent evidence suggests that neurodegeneration during prion pathogenesis is a consequence of a complex interplay between neuronal and non-neuronal cells in the brain,but the exact role of these non-neuronal cells during prion pathology is still elusive.Astrocytes are non-neuronal cells that regulate brain homeostasis under physiological conditions.However,astrocytes can deposit PrPSc aggregates and propagate prions in prion-infected brains.Additionally,sub-populations of reactive astrocytes that include neurotrophic and neurotoxic species have been identified,differentially expressed in the brain during prion infection.Revealing the exact role of astrocytes in prion disease is hampered by the lack of in vitro models of prion-infected astrocytes.Recently,we established a murine astrocyte cell line persistently infected with mouse-adapted prions,and showed how such astrocytes differentially process various prion strains.Considering the complexity of the role of astrocytes in prion pathogenesis,we need more in vitro and in vivo models for exploring the contribution of sub-populations of reactive astrocytes,their differential regulation of signaling cascades,and the interaction with neurons and microglia during prion pathogenesis.This will help to establish novel in vivo models and define new therapeutic targets against prion diseases.In this review,we will discuss the complex role of astrocytes in prion disease,the existing experimental resources,the challenges to analyze the contribution of astrocytes in prion disease pathogenesis,and future strategies to improve the understanding of their role in prion disease.展开更多
The baker's yeast Saccharomyces(S.)cerevisiae is a single-celled eukaryotic model organism widely used in research on life sciences.Being a unicellular organism,S.cerevisiae has some evident limitations in applica...The baker's yeast Saccharomyces(S.)cerevisiae is a single-celled eukaryotic model organism widely used in research on life sciences.Being a unicellular organism,S.cerevisiae has some evident limitations in application to neuroscience.However,yeast prions are extensively studied and they are known to share some hallmarks with mammalian prion protein or other amyloidogenic proteins found in the pathogenesis of Alzheimer's,Parkinson's,or Huntington's diseases.Therefore,the yeast S.cerevisiae has been widely used for basic research on aggregation properties of proteins in cellulo and on their propagation.Recently,a yeast-based study revealed that some regions of mammalian prion protein and amyloidβ1–42 are capable of induction and propagation of yeast prions.It is one of the examples showing that evolutionarily distant organisms share common mechanisms underlying the structural conversion of prion proteins making yeast cells a useful system for studying mammalian prion protein.S.cerevisiae has also been used to design novel screening systems for anti-prion compounds from chemical libraries.Yeastbased assays are cheap in maintenance and safe for the researcher,making them a very good choice to perform preliminary screening before further characterization in systems engaging mammalian cells infected with prions.In this review,not only classical red/white colony assay but also yeast-based screening assays developed during last year are discussed.Computational analysis and research carried out using yeast prions force us to expect that prions are widely present in nature.Indeed,the last few years brought us several examples indicating that the mammalian prion protein is no more peculiar protein–it seems that a better understanding of prion proteins nature-wide may aid us with the treatment of prion diseases and other amyloid-related medical conditions.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos.52073128,12164002,and 11964012)the Foundation of Educational Committee of Jiangxi Province of China (Grant No.GJJ211112)the Fund for Distinguished Young Scholars of Jiangxi Science&Technology Normal University (Grant No.2015QNBJRC002)。
文摘Prion diseases are a class of fatal neurodegenerative diseases caused by misfolded prion proteins.The main reason is that pathogenic prion protein has a strong tendency to aggregate,which easily induces the damage to the central nervous system.Point mutations in the human prion protein gene can cause prion diseases such as Creutzfeldt-Jakob and Gerstmann's syndrome.To understand the mechanism of mutation-induced prion protein aggregation,the mutants in an aqueous solution are studied by molecular dynamics simulations,including the wild type,V180I,H187R and a double point mutation which is associated with CJD and GSS.After running simulations for 500 ns,the results show that these three mutations have different effects on the kinetic properties of PrP.The high fluctuations around the N-terminal residues of helix 2 in the V180I variant lead to a decrease in hydrogen bonding on helix 2,while an increase in the number of hydrogen bonds between the folded regions promotes the generation ofβ-sheet.Meanwhile,partial deletion of salt bridges in the H187R and double mutants allows the sub-structural domains of the prion protein to separate,which would accelerate the conversion from PrPC to PrPSc.A similar trend is observed in both SASA and Rg for all three mutations,indicating that the conformational space is reduced and the structure is compact.
文摘Prions are infectious conformations of certain naturally occurring proteins.These misfolded proteins can structurally alter healthy protein,creating misfolded copies that repeat the process and form protein aggregates that lead to neuronal cell death.Although years can pass from initial prion infection to clinical presentation of symptoms,onset of symptoms is typically followed by rapid neurological decline resulting in death.Prion diseases have been characterized in animals ranging from sheep and cattle to cervids and humans,with notable cross-species infections such as the variant Creutzfeldt-Jakob disease.Thus,prions present a health risk with the potential to disrupt major food sources as well affect human health through animal to human and human to human transmission events.While human to human prion transmission is rare and the immediate risks for a prion-facilitated pandemic are low,prions are a class of pathogens for which we are underprepared.In addition,prions,and prion disease-like approaches,have also been discussed in the context of biological weapons and toxins,adding another layer of complexity surrounding biosecurity and biodefense.These threats underscore the need for increased scrutiny and research on prions.Here,pharmaceutical and nonpharmaceutical prion-specific interventions are discussed.Recent advances in prion therapeutic development are also briefly highlighted,and a set of policy recommendations are given that aims to provide high level suggestions for the prevention and mitigation of prion diseases.
基金supported by grants from Alberta Innovates/Alberta Prion Research Institute(APRI grants 201600010 and 201900008)(to HMS)ST had received a University of Calgary Eyes High,Killam and Alberta Innovates Health Solution(AIHS)doctoral fellowship.
文摘Prion diseases are infectious protein misfolding disorders of the central nervous system that result from misfolding of the cellular prion protein(PrPC)into the pathologic isoform PrPSc.Pathologic hallmarks of prion disease are depositions of pathological prion protein PrPSc,neuronal loss,spongiform degeneration and astrogliosis in the brain.Prion diseases affect human and animals,there is no effective therapy,and they invariably remain fatal.For a long time,neuronal loss was considered the sole reason for neurodegeneration in prion pathogenesis,and the contribution of non-neuronal cells like microglia and astrocytes was considered less important.Recent evidence suggests that neurodegeneration during prion pathogenesis is a consequence of a complex interplay between neuronal and non-neuronal cells in the brain,but the exact role of these non-neuronal cells during prion pathology is still elusive.Astrocytes are non-neuronal cells that regulate brain homeostasis under physiological conditions.However,astrocytes can deposit PrPSc aggregates and propagate prions in prion-infected brains.Additionally,sub-populations of reactive astrocytes that include neurotrophic and neurotoxic species have been identified,differentially expressed in the brain during prion infection.Revealing the exact role of astrocytes in prion disease is hampered by the lack of in vitro models of prion-infected astrocytes.Recently,we established a murine astrocyte cell line persistently infected with mouse-adapted prions,and showed how such astrocytes differentially process various prion strains.Considering the complexity of the role of astrocytes in prion pathogenesis,we need more in vitro and in vivo models for exploring the contribution of sub-populations of reactive astrocytes,their differential regulation of signaling cascades,and the interaction with neurons and microglia during prion pathogenesis.This will help to establish novel in vivo models and define new therapeutic targets against prion diseases.In this review,we will discuss the complex role of astrocytes in prion disease,the existing experimental resources,the challenges to analyze the contribution of astrocytes in prion disease pathogenesis,and future strategies to improve the understanding of their role in prion disease.
基金funded by the Polish National Science Centre MINIATURA3,grant No.501/66 GR-6220(to TI)。
文摘The baker's yeast Saccharomyces(S.)cerevisiae is a single-celled eukaryotic model organism widely used in research on life sciences.Being a unicellular organism,S.cerevisiae has some evident limitations in application to neuroscience.However,yeast prions are extensively studied and they are known to share some hallmarks with mammalian prion protein or other amyloidogenic proteins found in the pathogenesis of Alzheimer's,Parkinson's,or Huntington's diseases.Therefore,the yeast S.cerevisiae has been widely used for basic research on aggregation properties of proteins in cellulo and on their propagation.Recently,a yeast-based study revealed that some regions of mammalian prion protein and amyloidβ1–42 are capable of induction and propagation of yeast prions.It is one of the examples showing that evolutionarily distant organisms share common mechanisms underlying the structural conversion of prion proteins making yeast cells a useful system for studying mammalian prion protein.S.cerevisiae has also been used to design novel screening systems for anti-prion compounds from chemical libraries.Yeastbased assays are cheap in maintenance and safe for the researcher,making them a very good choice to perform preliminary screening before further characterization in systems engaging mammalian cells infected with prions.In this review,not only classical red/white colony assay but also yeast-based screening assays developed during last year are discussed.Computational analysis and research carried out using yeast prions force us to expect that prions are widely present in nature.Indeed,the last few years brought us several examples indicating that the mammalian prion protein is no more peculiar protein–it seems that a better understanding of prion proteins nature-wide may aid us with the treatment of prion diseases and other amyloid-related medical conditions.
