Journal Article

DZNE-2025-00896

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Most L1CAM Is not Associated with Extracellular Vesicles in Human Biofluids and iPSC-Derived Neurons.

Kadam, V.DZNE* ; Wacker, M.DZNE* ; Oeckl, P.DZNE* ; Korneck, M.DZNE* ; Dannenmann, B. ; Skokowa, J. ; Hauser, S.DZNE* ; Otto, M. ; Synofzik, M. (Last author)DZNE* ; Mengel, D. (Last author)DZNE*

2025
Humana Press Totowa, NJ

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Please use a persistent id in citations: doi:10.1007/s12035-025-04909-2

Abstract: Transmembrane L1 cell adhesion molecule (L1CAM) is widely used as a marker to enrich for neuron-derived extracellular vesicles (EVs), especially in plasma. However, this approach lacks sufficient robust validation. This study aimed to assess whether human biofluids are indeed enriched for EVs, particularly neuron-derived EVs, by L1CAM immunoaffinity, utilizing multiple sources (plasma, CSF, conditioned media from iPSC-derived neurons [iNCM]) and different methods (mass spectrometry [MS], nanoparticle tracking analysis [NTA]). Following a systematic multi-step validation approach, we confirmed isolation of generic EV populations using size-exclusion chromatography (SEC) and polymer-aided precipitation (PPT)-two most commonly applied EV isolation methods-from all sources. Neurofilament light (NfL) was detected in both CSF and blood-derived EVs, indicating their neuronal origin. However, L1CAM immunoprecipitation did not yield enrichment of L1CAM in EV fractions. Instead, it was predominantly found in its free-floating form. Additionally, MS-based proteomic analysis of CSF-derived EVs also did not show L1CAM enrichment. Our study validates EV isolation from diverse biofluid sources by several isolation approaches and confirms that some EV subpopulations in human biofluids are of neuronal origin. Thorough testing across multiple sources by different orthogonal methods, however, does not support L1CAM as a marker to reliably enrich for a specific subpopulation of EVs, particularly of neuronal origin.

Keyword(s): Humans (MeSH) ; Extracellular Vesicles: metabolism (MeSH) ; Neural Cell Adhesion Molecule L1: metabolism (MeSH) ; Neurons: metabolism (MeSH) ; Induced Pluripotent Stem Cells: metabolism (MeSH) ; Induced Pluripotent Stem Cells: cytology (MeSH) ; Proteomics (MeSH) ; Body Fluids: metabolism (MeSH) ; Biomarkers ; Blood ; Cerebrospinal fluid ; Extracellular vesicles ; Immunoprecipitation ; Isolation methods ; L1CAM ; Neuron ; Neural Cell Adhesion Molecule L1 ; L1CAM protein, human

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Contributing Institute(s):

1. Parkinson Genetics (AG Gasser)
2. Translational Mass Spectrometry and Biomarker Research (AG Öckl)
3. Advanced cellular models of neurodegeneration (AG Hauser)

Research Program(s):

1. 353 - Clinical and Health Care Research (POF4-353) (POF4-353)
2. 352 - Disease Mechanisms (POF4-352) (POF4-352)

Appears in the scientific report 2025

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Database coverage:
; ; ; BIOSIS Previews ; Biological Abstracts ; Clarivate Analytics Master Journal List ; DEAL Springer ; Essential Science Indicators ; IF >= 5 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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