Abstract
Tissue spatially-resolved proteomics was performed on 3 brain regions, leading to the characterization of 123 reference proteins. Moreover, 8 alternative proteins from alternative open reading frames (AltORF) were identified. Some proteins display specific post-translational modification profiles or truncation linked to the brain regions and their functions. Systems biology analysis performed on the proteome identified in each region allowed to associate sub-networks with the functional physiology of each brain region. Back correlation of the proteins identified by spatially-resolved proteomics at a given tissue localization with the MALDI MS imaging data, was then performed. As an example, mapping of the distribution of the matrix metallopeptidase 3-cleaved C-terminal fragment of α-synuclein (aa 95–140) identified its specific distribution along the hippocampal dentate gyrus. Taken together, we established the molecular physiome of 3 rat brain regions through reference and hidden proteome characterization.
Highlights
From the ‡Laboratoire Proteomique, Reponse Inflammatoire et Spectrometrie de Masse (PRISM) - INSERM U1192, Universite Lille 1, Bat SN3, 1er etage, Cite Scientifique, F-59655 Villeneuve d’Ascq Cedex, France; §Departement de Biochimie Lab
Its importance is evident in physiopathological diseases such as cancer, where proteomic analysis of the complete tissue does not take into account tumor heterogeneity and the cellular cross-talks occurring in different regions of the tumor [2,3,4,5,6,7,8]
Combined with MALDI mass spectrometry imaging (MSI)1, which can map the distribution of molecules [9, 10], on-tissue spatially-resolved proteomics can provide details of the molecular events occurring at cellular level in such discrete regions
Summary
Experimental Design and Statistical Rationale—We first acquired MS images of lipids These images were subjected to spatial segmentation to identify regions of interest (ROIs) that can be subjected to LMJ or PAM spatially-resolved proteomics. For this purpose, several tissue sections were obtained from rat brain. LMJ Experiments—To ensure optimal protein extraction, lipids were depleted from the tissue section by immersing the glass slides in consecutive solvent baths consisting of 70 and 95% EtOH (1 min each time) and chloroform (30 s) with complete solvent evaporation under reduced pressure at room temperature between each washing step. Processing of the images was performed using Zen version and applied on the entire images as well as on controls
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
