Amyloid-b,tau pathology,and biomarkers of neurodegeneration make up the core diagnostic biomarkers of Alzheimer disease(AD).However,these proteins represent only a fraction of the complex biological processes underlyi...Amyloid-b,tau pathology,and biomarkers of neurodegeneration make up the core diagnostic biomarkers of Alzheimer disease(AD).However,these proteins represent only a fraction of the complex biological processes underlying AD,and individuals with other brain diseases in which AD pathology is a comorbidity also test positive for these diagnostic biomarkers.More ADspecific early diagnostic and disease staging biomarkers are needed.In this study,we performed tandem mass tag proteomic analysis of paired cerebrospinal fluid(CSF)and serum samples in a discovery cohort comprising 98 participants.Candidate biomarkers were validated by parallel reaction monitoring–based targeted proteomic assays in an independent multicenter cohort comprising 288 participants.We quantified 3,238 CSF and 1,702 serum proteins in the discovery cohort,identifying 171 and 860 CSF proteins and 37 and 323 serum proteins as potential early diagnostic and staging biomarkers,respectively.In the validation cohort,58 and 21 CSF proteins,as well as 12 and 18 serum proteins,were verified as early diagnostic and staging biomarkers,respectively.Separate 19-protein CSF and an 8-protein serum biomarker panels were built by machine learning to accurately classify mild cognitive impairment(MCI)due to AD from normal cognition with areas under the curve of 0.984 and 0.881,respectively.The 19-protein CSF biomarker panel also effectively discriminated patients with MCI due to AD from patients with other neurodegenerative diseases.Moreover,we identified 21 CSF and 18 serum stage-associated proteins re-flecting AD stages.Our findings provide a foundation for developing bloodbased tests for AD screening and staging in clinical practice.展开更多
Background Alzheimer’s disease(AD)is the most common form of neurodegenerative disorder,which is characterized by a decline in cognitive abilities.Genome-wide association and clinicopathological studies have demonstr...Background Alzheimer’s disease(AD)is the most common form of neurodegenerative disorder,which is characterized by a decline in cognitive abilities.Genome-wide association and clinicopathological studies have demonstrated that the CD2-associated protein(CD2AP)gene is one of the most important genetic risk factors for AD.However,the precise mechanisms by which CD2AP is linked to AD pathogenesis remain unclear.Methods The spatiotemporal expression pattern of CD2AP was determined.Then,we generated and characterized an APP/PS1 mouse model with neuron-specific Cd2ap deletion,using immunoblotting,immunofluorescence,enzyme-linked immunosorbent assay,electrophysiology and behavioral tests.Additionally,we established a stable CD2AP-knockdown SH-SY5Y cell line to further elucidate the specific molecular mechanisms by which CD2AP contributes to AD pathogenesis.Finally,the APP/PS1 mice with neuron-specific Cd2ap deletion were treated with an inhibitor targeting the pathway identified above to further validate our findings.Results CD2AP is widely expressed in various regions of the mouse brain,with predominant expression in neurons and vascular endothelial cells.In APP/PS1 mice,neuronal knockout of Cd2ap significantly aggravated tau pathology,synaptic impairments and cognitive deficits.Mechanistically,the knockout of Cd2ap activated p38 mitogen-activated protein kinase(MAPK)signaling,which contributed to increased tau phosphorylation,synaptic injury,neuronal apoptosis and cognitive impairment.Furthermore,the phenotypes of neuronal Cd2ap knockout were ameliorated by a p38 MAPK inhibitor.Conclusion Our study presents the first in vivo evidence that CD2AP deficiency exacerbates the phenotypes and pathology of AD through the p38 MAPK pathway,identifying CD2AP/p38 MAPK as promising therapeutic targets for AD.展开更多
基金This work was supported by grants from the Key Research and Development project of Zhejiang Province(2019C03039)the National Natural Science Foundation of China(81970998)+1 种基金the Science Innovation 2030-Brain Science and Brain-Inspired Intelligence Technology Major Projects(nos.2021ZD0201103 and 2021ZD0201803)the Integrative Traditional Chinese and Western Medicine Innovation Team for Neurodegenerative Diseases of Zhejiang Province.
文摘Amyloid-b,tau pathology,and biomarkers of neurodegeneration make up the core diagnostic biomarkers of Alzheimer disease(AD).However,these proteins represent only a fraction of the complex biological processes underlying AD,and individuals with other brain diseases in which AD pathology is a comorbidity also test positive for these diagnostic biomarkers.More ADspecific early diagnostic and disease staging biomarkers are needed.In this study,we performed tandem mass tag proteomic analysis of paired cerebrospinal fluid(CSF)and serum samples in a discovery cohort comprising 98 participants.Candidate biomarkers were validated by parallel reaction monitoring–based targeted proteomic assays in an independent multicenter cohort comprising 288 participants.We quantified 3,238 CSF and 1,702 serum proteins in the discovery cohort,identifying 171 and 860 CSF proteins and 37 and 323 serum proteins as potential early diagnostic and staging biomarkers,respectively.In the validation cohort,58 and 21 CSF proteins,as well as 12 and 18 serum proteins,were verified as early diagnostic and staging biomarkers,respectively.Separate 19-protein CSF and an 8-protein serum biomarker panels were built by machine learning to accurately classify mild cognitive impairment(MCI)due to AD from normal cognition with areas under the curve of 0.984 and 0.881,respectively.The 19-protein CSF biomarker panel also effectively discriminated patients with MCI due to AD from patients with other neurodegenerative diseases.Moreover,we identified 21 CSF and 18 serum stage-associated proteins re-flecting AD stages.Our findings provide a foundation for developing bloodbased tests for AD screening and staging in clinical practice.
基金supported by grants from the National Natural Science Foundation of China(81970998)the Science Innovation 2030-Brain Science and Brain-Inspired Intelligence Technology Major Projects(Nos.2021ZD0201103 and 2021ZD0201803)the Key R&D Program of Zhejiang(2024SSYS0018).
文摘Background Alzheimer’s disease(AD)is the most common form of neurodegenerative disorder,which is characterized by a decline in cognitive abilities.Genome-wide association and clinicopathological studies have demonstrated that the CD2-associated protein(CD2AP)gene is one of the most important genetic risk factors for AD.However,the precise mechanisms by which CD2AP is linked to AD pathogenesis remain unclear.Methods The spatiotemporal expression pattern of CD2AP was determined.Then,we generated and characterized an APP/PS1 mouse model with neuron-specific Cd2ap deletion,using immunoblotting,immunofluorescence,enzyme-linked immunosorbent assay,electrophysiology and behavioral tests.Additionally,we established a stable CD2AP-knockdown SH-SY5Y cell line to further elucidate the specific molecular mechanisms by which CD2AP contributes to AD pathogenesis.Finally,the APP/PS1 mice with neuron-specific Cd2ap deletion were treated with an inhibitor targeting the pathway identified above to further validate our findings.Results CD2AP is widely expressed in various regions of the mouse brain,with predominant expression in neurons and vascular endothelial cells.In APP/PS1 mice,neuronal knockout of Cd2ap significantly aggravated tau pathology,synaptic impairments and cognitive deficits.Mechanistically,the knockout of Cd2ap activated p38 mitogen-activated protein kinase(MAPK)signaling,which contributed to increased tau phosphorylation,synaptic injury,neuronal apoptosis and cognitive impairment.Furthermore,the phenotypes of neuronal Cd2ap knockout were ameliorated by a p38 MAPK inhibitor.Conclusion Our study presents the first in vivo evidence that CD2AP deficiency exacerbates the phenotypes and pathology of AD through the p38 MAPK pathway,identifying CD2AP/p38 MAPK as promising therapeutic targets for AD.
