Division of Cell Matrix Biology & Regenerative Medicine, Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester M13 9PT, UK.
Department of Human Genetics, Wellcome Sanger Institute, Genome Campus, Hinxton CB10 1SA, UK.
Int J Mol Sci. 2021 Sep 27;22(19):10408. doi: 10.3390/ijms221910408.
In ageing tissues, long-lived extracellular matrix (ECM) proteins are susceptible to the accumulation of structural damage due to diverse mechanisms including glycation, oxidation and protease cleavage. Peptide location fingerprinting (PLF) is a new mass spectrometry (MS) analysis technique capable of identifying proteins exhibiting structural differences in complex proteomes. PLF applied to published young and aged intervertebral disc (IVD) MS datasets (posterior, lateral and anterior regions of the annulus fibrosus) identified 268 proteins with age-associated structural differences. For several ECM assemblies (collagens I, II and V and aggrecan), these differences were markedly conserved between degeneration-prone (posterior and lateral) and -resistant (anterior) regions. Significant differences in peptide yields, observed within collagen I α2, collagen II α1 and collagen V α1, were located within their triple-helical regions and/or cleaved C-terminal propeptides, indicating potential accumulation of damage and impaired maintenance. Several proteins (collagen V α1, collagen II α1 and aggrecan) also exhibited tissue region (lateral)-specific differences in structure between aged and young samples, suggesting that some ageing mechanisms may act locally within tissues. This study not only reveals possible age-associated differences in ECM protein structures which are tissue-region specific, but also highlights the ability of PLF as a proteomic tool to aid in biomarker discovery.
在衰老组织中，由于多种机制（包括糖化、氧化和蛋白酶切割）的作用，长寿的细胞外基质（ECM）蛋白容易积累结构损伤。肽位置指纹图谱（PLF）是一种新的质谱（MS）分析技术，能够识别复杂蛋白质组中表现出结构差异的蛋白质。PLF 应用于已发表的年轻和衰老椎间盘（IVD）MS 数据集（纤维环的后、侧和前区），鉴定出 268 种与年龄相关的具有结构差异的蛋白质。对于几种 ECM 组件（I 型、II 型和 V 型胶原和聚集蛋白聚糖），这些差异在易退变（后、侧）和不易退变（前）区域之间明显保守。在 I 型胶原 α2、II 型胶原 α1 和 V 型胶原 α1 中观察到的肽产量显著差异位于其三螺旋区和/或切割的 C 端前肽内，表明潜在的损伤积累和受损的维持。几种蛋白质（V 型胶原 α1、II 型胶原 α1 和聚集蛋白聚糖）在年轻和老年样本之间在结构上也表现出组织区域（侧）特异性差异，表明一些衰老机制可能在组织内局部起作用。这项研究不仅揭示了 ECM 蛋白结构可能与年龄相关的组织区域特异性差异，还强调了 PLF 作为一种蛋白质组学工具在生物标志物发现中的辅助能力。
