Inkinen R I, Lammi M J, Lehmonen S, Puustjärvi K, Kääpä E, Tammi M I
Department of Anatomy, University of Kuopio, Finland.
J Rheumatol. 1998 Mar;25(3):506-14.
Proteoglycans are major components of the extracellular matrix of the intervertebral disc. They are vital for the biomechanical properties of the tissue, and are subject to changes in disc degeneration. We aimed to further define these changes and their relationship to normal aging.
Normal discs (age 13-53 years, n = 6) were analyzed from 5 different sites across the sagittal anterior-posterior direction. Degenerated anterior annulus fibrosus was collected from 7 patients aged 39-46 years. Extracted proteoglycans were separated using agarose and polyacrylamide gel electrophoresis and detected with toluidine blue staining and Western blotting.
The center of the disc showed the highest level of total proteoglycans, but lowest levels of decorin and biglycan. Western blots displayed reduced signal for both glycanated and nonglycanated biglycan and decorin after adolescence, while an increased signal of biglycan was observed in degenerated annuli. The 7D4(-) and 3B3(-) epitopes on native chondroitin sulfate chains were present in the large proteoglycans of intervertebral discs, but their signal intensity had no correlation to degeneration. Chondroitinase ABC digestion of the blots brought up 7D4(+) signal in the small proteoglycans of degenerated, but not in healthy tissue. Decrease or total loss of 2B6(+) epitope (indicating 4-sulfated stubs of chondroitin sulfate chains) were found in the large proteoglycans of all degenerated annuli.
Human intervertebral disc degeneration involves the accumulation of decorin and biglycan relative to other uronic acid containing proteoglycans, the disappearance of 4-sulfated core region in aggrecan-like large proteoglycans, and the emergence of a core structure in the chains of small proteoglycans reacting with the 7D4 antibody; these findings indicate a fundamental alteration in matrix properties that may contribute to the pathogenesis of the disease.
蛋白聚糖是椎间盘细胞外基质的主要成分。它们对于组织的生物力学特性至关重要，并且在椎间盘退变过程中会发生变化。我们旨在进一步明确这些变化及其与正常衰老的关系。
从矢状前后方向的5个不同部位分析了6个正常椎间盘（年龄13 - 53岁）。收集了7例年龄在39 - 46岁患者的退变纤维环前部组织。提取的蛋白聚糖通过琼脂糖和聚丙烯酰胺凝胶电泳进行分离，并用甲苯胺蓝染色和蛋白质印迹法进行检测。
椎间盘中心显示总蛋白聚糖水平最高，但核心蛋白聚糖和双糖链蛋白聚糖水平最低。蛋白质印迹显示青春期后糖化和非糖化双糖链蛋白聚糖及核心蛋白聚糖的信号均降低，而在退变纤维环中观察到双糖链蛋白聚糖信号增加。天然硫酸软骨素链上的7D4(-)和3B3(-)表位存在于椎间盘的大蛋白聚糖中，但其信号强度与退变无关。对印迹进行软骨素酶ABC消化后，在退变组织的小蛋白聚糖中出现了7D4(+)信号，而在健康组织中未出现。在所有退变纤维环的大蛋白聚糖中均发现2B6(+)表位（表明硫酸软骨素链的4 - 硫酸化残端）减少或完全缺失。
人类椎间盘退变涉及核心蛋白聚糖和双糖链蛋白聚糖相对于其他含糖醛酸蛋白聚糖的积累、聚集蛋白聚糖样大蛋白聚糖中4 - 硫酸化核心区域的消失以及与7D4抗体反应的小蛋白聚糖链中核心结构的出现；这些发现表明基质特性发生了根本性改变，可能有助于该疾病的发病机制。
