Halfter Willi, Moes Suzette, Asgeirsson Daphne O, Halfter Kathrin, Oertle Philipp, Melo Herraiz Esther, Plodinec Marija, Jenoe Paul, Henrich Paul Bernhard
Department of Ophthalmology, University of Basel, Basel, Switzerland.
Proteomics Core Facility, Biocenter of the University of Basel, Basel, Switzerland.
PLoS One. 2017 Dec 28;12(12):e0189857. doi: 10.1371/journal.pone.0189857. eCollection 2017.
Basement membranes (BMs) are specialized sheets of extracellular matrix that outline epithelial cell layers, muscle fibers, blood vessels, and peripheral nerves. A well-documented histological hallmark of progressing diabetes is a major increase in vascular BM thickness. In order to investigate whether this structural change is accompanied by a change in the protein composition, we compared the proteomes of retinal vascular BMs from diabetic and non-diabetic donors by using LC-MS/MS. Data analysis showed that seventeen extracellular matrix (ECM)-associated proteins were more abundant in diabetic than non-diabetic vascular BMs. Four ECM proteins were more abundant in non-diabetic than in diabetic BMs. Most of the over-expressed proteins implicate a complement-mediated chronic inflammatory process in the diabetic retinal vasculature. We also found an up-regulation of norrin, a protein that is known to promote vascular proliferation, possibly contributing to the vascular remodeling during diabetes. Many of the over-expressed proteins were localized to microvascular aneurisms. Further, the overall stoichiometry of proteins was changed, such that the relative abundance of collagens in BMs from diabetic patients was higher than normal. Biomechanical measurements of vascular BM flat mounts using AFM showed that their outer surface was softer than normal.
基底膜（BMs）是细胞外基质的特殊薄片，勾勒出上皮细胞层、肌纤维、血管和周围神经。糖尿病进展的一个有充分文献记载的组织学特征是血管基底膜厚度大幅增加。为了研究这种结构变化是否伴随着蛋白质组成的改变，我们使用液相色谱-串联质谱法（LC-MS/MS）比较了糖尿病和非糖尿病供体视网膜血管基底膜的蛋白质组。数据分析表明，17种细胞外基质（ECM）相关蛋白在糖尿病血管基底膜中比在非糖尿病血管基底膜中更为丰富。4种ECM蛋白在非糖尿病基底膜中比在糖尿病基底膜中更为丰富。大多数过表达的蛋白表明糖尿病视网膜血管中存在补体介导的慢性炎症过程。我们还发现诺林（Norrin）上调，诺林是一种已知可促进血管增殖的蛋白，可能在糖尿病期间促成血管重塑。许多过表达的蛋白定位于微血管动脉瘤。此外，蛋白质的整体化学计量发生了变化，使得糖尿病患者基底膜中胶原蛋白的相对丰度高于正常水平。使用原子力显微镜（AFM）对血管基底膜平片进行的生物力学测量表明，其外表面比正常情况更柔软。
