Open AccessMatrix‐assisted laser desorption ionization–imaging mass spectrometry: A new methodology to study human osteoarthritic cartilage
Author(s) -
CilleroPastor Berta,
Eijkel Gert B.,
Kiss Andras,
Blanco Francisco J.,
Heeren Ron M. A.
Publication year - 2013
Publication title -
arthritis & rheumatism
Language(s) - English
Resource type - Journals
eISSN - 1529-0131
pISSN - 0004-3591
DOI - 10.1002/art.37799
Subject(s) - cartilage , aggrecan , mass spectrometry imaging , chemistry , osteoarthritis , mass spectrometry , matrix assisted laser desorption/ionization , fibronectin , cartilage oligomeric matrix protein , matrix (chemical analysis) , pathology , extracellular matrix , microbiology and biotechnology , anatomy , biochemistry , biology , medicine , articular cartilage , chromatography , desorption , alternative medicine , organic chemistry , adsorption
Objective Information about the distribution of proteins and the modulation that they undergo in the different phases of rheumatic pathologies is essential to understanding the development of these diseases. We undertook this study to demonstrate the utility of mass spectrometry (MS)–based molecular imaging for studying the spatial distribution of different components in human articular cartilage sections. Methods We compared the distribution of peptides and proteins in human control and osteoarthritic (OA) cartilage. Human control and OA cartilage slices were cut and deposited on conductive slides. After tryptic digestion, we performed matrix‐assisted laser desorption ionization–imaging MS (MALDI‐IMS) experiments in a MALDI–quadrupole time‐of‐flight mass spectrometer. Protein identification was undertaken with a combination of multivariate statistical methods and Mascot protein database queries. Hematoxylin and eosin staining and immunohistochemistry were performed to validate the results. Results We created maps of peptide distributions at 150‐μm raster size from control and OA human cartilage. Proteins such as biglycan, prolargin, decorin, and aggrecan core protein were identified and localized. Specific protein markers for cartilage oligomeric matrix protein and fibronectin were found exclusively in OA cartilage samples. Their distribution displayed a stronger intensity in the deep area than in the superficial area. New tentative OA markers were found in the deep area of the OA cartilage. Conclusion MALDI‐IMS identifies and localizes disease‐specific peptides and proteins in cartilage. All the OA‐related peptides and proteins detected display a stronger intensity in the deep cartilage. MS‐based molecular imaging is demonstrated to be an innovative method for studying OA pathology.