Multiplex LA-ICP-MS bio-imaging of brain tissue of a parkinsonian mouse model stained with metal-coded affinity-tagged antibodies and coated with indium-spiked commercial inks as internal standards.

DOTA-labelling immunohistochemistry Imaging Inkjet-Printing Internal standardization LA-ICP-MS Parkinson’s disease

Journal

Journal of neuroscience methods
ISSN: 1872-678X
Titre abrégé: J Neurosci Methods
Pays: Netherlands
ID NLM: 7905558

Informations de publication

Date de publication:
08 Jan 2020
Historique:
received: 03 09 2019
revised: 18 12 2019
accepted: 07 01 2020
pubmed: 12 1 2020
medline: 12 1 2020
entrez: 12 1 2020
Statut: aheadofprint

Résumé

Immunohistochemistry techniques represent a powerful tool to detect and quantify disease related proteins. Improvements were accomplished by tagged antibodies using laser ablation and inductively coupled plasma mass spectrometry (LA-ICP-MS). However, these approaches are effected by day-to-variations due to instrumental drift. Brain tissue from line 62, a Parkinson's disease model, and control mice were incubated with four antibodies relevant to the disease and standardized to three house-keeping proteins. In addition, a new standardization approach was developed and the results compared. This new approach consisted of coating specimens with gelatin and printing an indium-doped ink with a commercial ink jet printer. Furthermore, the method was evaluated for different ablation spot sizes with respect to resolution and signal-to-noise ratio. Normalization using house-keeping proteins led to high background signals even at high resolution. Normalization using indium-doped ink improved the signal-to-noise ratio even when small laser spot sizes were used and further improved by overlaying tissue specimen with gelatin. Line 62 mice had more α-Synuclein and gliosis but decreased numbers of neurons, as found by conventional immunohistochemistry. These data are in line with the results obtained by LA-ICP-MS with indium standardization. However, differences between L62 and controls for tyrosine hydroxylase were only detected by LA-ICP-MS. Internal standardisation using indium-doped inks is an effective method to overcome day-to-day variations and instrumental drifts. The new approach results in an increased signal-to-noise ratio and only under these conditions small but significant changes were detected, as seen for tyrosine hydroxylase.

Sections du résumé

BACKGROUND BACKGROUND
Immunohistochemistry techniques represent a powerful tool to detect and quantify disease related proteins. Improvements were accomplished by tagged antibodies using laser ablation and inductively coupled plasma mass spectrometry (LA-ICP-MS). However, these approaches are effected by day-to-variations due to instrumental drift.
NEW METHOD METHODS
Brain tissue from line 62, a Parkinson's disease model, and control mice were incubated with four antibodies relevant to the disease and standardized to three house-keeping proteins. In addition, a new standardization approach was developed and the results compared. This new approach consisted of coating specimens with gelatin and printing an indium-doped ink with a commercial ink jet printer. Furthermore, the method was evaluated for different ablation spot sizes with respect to resolution and signal-to-noise ratio.
RESULTS RESULTS
Normalization using house-keeping proteins led to high background signals even at high resolution. Normalization using indium-doped ink improved the signal-to-noise ratio even when small laser spot sizes were used and further improved by overlaying tissue specimen with gelatin.
COMPARISON WITH EXISTING METHODS METHODS
Line 62 mice had more α-Synuclein and gliosis but decreased numbers of neurons, as found by conventional immunohistochemistry. These data are in line with the results obtained by LA-ICP-MS with indium standardization. However, differences between L62 and controls for tyrosine hydroxylase were only detected by LA-ICP-MS.
CONCLUSIONS CONCLUSIONS
Internal standardisation using indium-doped inks is an effective method to overcome day-to-day variations and instrumental drifts. The new approach results in an increased signal-to-noise ratio and only under these conditions small but significant changes were detected, as seen for tyrosine hydroxylase.

Identifiants

DOI: 10.1016/j.jneumeth.2020.108591 PMID: 31926203
pubmed: 31926203
pii: S0165-0270(20)30013-3
doi: 10.1016/j.jneumeth.2020.108591
pii:
doi:

Types de publication

Journal Article

Langues

eng

Sous-ensembles de citation

IM

Pagination

108591

Informations de copyright

Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.

Déclaration de conflit d'intérêts

Declaration of Competing Interest BN and SH were employed by Proteome Factory AG. NJ was employed by Spetec GmbH. The other authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Auteurs

Boris Neumann (B)

Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität Zu Berlin, and Berlin Institute of Health, Center for Cardiovascular Research, Institute of Pharmacology, Hessische Strasse 3-4, 10115 Berlin, Germany; Proteome Factory AG, Magnusstrasse 11, 12489 Berlin, Germany.

Simone Hösl (S)

Proteome Factory AG, Magnusstrasse 11, 12489 Berlin, Germany.

Karima Schwab (K)

Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität Zu Berlin, and Berlin Institute of Health, Center for Cardiovascular Research, Institute of Pharmacology, Hessische Strasse 3-4, 10115 Berlin, Germany. Electronic address: karima.schwab@charite.de.

Franz Theuring (F)

Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität Zu Berlin, and Berlin Institute of Health, Center for Cardiovascular Research, Institute of Pharmacology, Hessische Strasse 3-4, 10115 Berlin, Germany.

Norbert Jakubowski (N)

Spetec GmbH, Berghamer Str. 2, 85435 Erding, Germany.

Classifications MeSH