PXD022186

PXD022186 is an original dataset announced via ProteomeXchange.

Title	Detection and Quantification of Novel C-terminal TDP-43 Fragments in ALS-TDP
Description	The pathological hallmark of amyotrophic lateral sclerosis (ALS) is the presence of cytoplasmic inclusions, containing C-terminal fragments of the protein TDP-43. Here, we tested the hypothesis that highly sensitive mass spectrometry with parallel reaction monitoring (MS-PRM) can generate a high-resolution map of pathological TDP-43 peptide ratios to form the basis for quantitation of abnormal C-terminal TDP-43 fragment enrichment. Human cortex and spinal cord, microscopically staged for the presence of phosphoTDP-43, p-tau, alpha-synuclein and beta-amyloid pathology, were biochemically fractionated and analysed by immunoblot and MS for detection of full-length and truncated (disease-specific) TDP-43 peptides. This informed synthesis of heavy isotope-labelled peptides for the absolute quantification of TDP-43 by MS-PRM across 16 ALS, 8 Parkinson’s and 8 Alzheimer’s disease and 8 aged control cases. We confirmed by immunoblot the previously described enrichment of pathological C-terminal fragments in ALS-TDP urea fractions. Subsequent MS analysis resolved specific TDP-43 N- and C-terminal peptides, including a novel N-terminal truncation site-specific peptide. Absolute quantification of peptides by MS-PRM showed an increased C:N-terminal TDP-43 peptide ratio in ALS-TDP brain compared to normal and disease controls. A C:N-terminal ratio >1.5 discriminated ALS from controls with a sensitivity of 100% (CI 79.6-100) and specificity of 100% (CI 68-100), and from Parkinson’s and Alzheimer’s disease with a sensitivity of 93% (CI 70-100) and specificity of 100% (CI 68-100). N-terminal Truncation site-specific peptides were increased in ALS in line with C-terminal fragment enrichment, but also found in a proportion of Alzheimer cases with normal C:N-terminal ratio but coexistent TDP-43 pathology. In conclusion this is a novel, sensitive and specific method to quantify the enrichment of pathological TDP-43 fragments in human brain, which could form the basis for an antibody-free assay. Our methodology has the potential to help clarify if specific pathological TDP-43 peptide signatures are associated with primary or secondary TDP-43 proteinopathies.
HostingRepository	PRIDE
AnnounceDate	2020-12-17
AnnouncementXML	Submission_2020-12-17_05:58:44.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Roman Fischer
SpeciesList	scientific name: Homo sapiens (Human); NCBI TaxID: 9606;
ModificationList	No PTMs are included in the dataset
Instrument	Orbitrap Fusion Lumos

Revision	Datetime	Status	ChangeLog Entry
0	2020-10-26 05:13:07	ID requested
⏵ 1	2020-12-17 05:58:45	announced

Dataset with its publication pending

submitter keyword: TDP-43, PRM, ALS

Roman Fischer
contact affiliation	University of Oxford Target Discovery Institute
contact email	roman.fischer@ndm.ox.ac.uk
lab head
Roman Fischer
contact affiliation	University of Oxford
contact email	roman.fischer@ndm.ox.ac.uk
dataset submitter

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PRIDE project URI

• PRIDE
  1. PXD022186
     1. Label: PRIDE project
     2. Name: Detection and Quantification of Novel C-terminal TDP-43 Fragments in ALS-TDP