Cillero-Pastor Berta, Eijkel Gert B, Kiss Andras, Blanco Francisco J, Heeren Ron M A
FOM Institute AMOLF, Amsterdam, The Netherlands.
Arthritis Rheum. 2013 Mar;65(3):710-20. doi: 10.1002/art.37799.
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.
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.
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.
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.
了解蛋白质的分布及其在风湿性疾病不同阶段所经历的调节对于理解这些疾病的发展至关重要。我们开展这项研究以证明基于质谱（MS）的分子成像在研究人关节软骨切片中不同成分空间分布方面的实用性。
我们比较了人对照和骨关节炎（OA）软骨中肽和蛋白质的分布。将人对照和OA软骨切片切割后沉积在导电载玻片上。经胰蛋白酶消化后，我们在基质辅助激光解吸电离成像质谱仪（MALDI-IMS）中进行了基质辅助激光解吸电离成像质谱实验。结合多元统计方法和Mascot蛋白质数据库查询进行蛋白质鉴定。进行苏木精和伊红染色以及免疫组织化学以验证结果。
我们创建了来自对照和OA人软骨的150-μm光栅尺寸的肽分布图。鉴定并定位了诸如双糖链蛋白聚糖、脯氨酸丰富蛋白、核心蛋白聚糖和聚集蛋白聚糖核心蛋白等蛋白质。软骨寡聚基质蛋白和纤连蛋白的特异性蛋白质标志物仅在OA软骨样品中发现。它们在深层区域的分布强度比浅层区域更强。在OA软骨深层区域发现了新的暂定OA标志物。
MALDI-IMS可识别并定位软骨中疾病特异性的肽和蛋白质。所有检测到的与OA相关的肽和蛋白质在深层软骨中的强度更强。基于MS的分子成像被证明是一种研究OA病理学的创新方法。
