Abstract:
Degeneration of the intervertebral disc is an age-related condition. It also accompanies the disappearance of the notochordal cells, which are remnants of the developmental stages of the nucleus pulposus (NP). Molecular changes such as extracellular matrix catabolism, cellular phenotype, and glycosaminoglycan loss in the NP have been extensively studied. However, as one of the most significant co- and posttranslational modifications, glycosylation has been overlooked in cells in degeneration. Here, we aim to characterize the N-glycome of young and mature NP and identify patterns related to aging. Accordingly, we isolated N-glycans from notochordal cell-rich NP from porcine discs, characterized them using a combined approach of exoglycosidase digestions and analysis with hydrophilic interaction ultra-performance liquid chromatography and mass spectrometry. We have assigned over 300 individual N-glycans for each age group. Moreover, we observed a notable abundance of antennary structures, galactosylation, fucosylation, and sialylation in both age groups. In addition, as indicated from our results, increasing outer arm fucosylation and decreasing α(2,3)-linked sialylation with aging suggest that these traits are age-dependent. Lastly, we have focused on an extensive characterization of the N-glycome of the notochordal cell-rich NP in aging without inferred degeneration, describing glycosylation changes specific for aging only. Our findings in combination with those of other studies, suggest that the degeneration of the NP does not involve identical processes as aging.
摘要:
椎间盘退变是与年龄有关的病症。它还伴随着脊索细胞的消失,是髓核(NP)发育阶段的残留物。分子变化,如细胞外基质分解代谢,细胞表型,和糖胺聚糖在NP中的损失已经被广泛研究。然而,作为最重要的共翻译和翻译后修饰之一,糖基化在变性细胞中被忽视。这里,我们旨在表征年轻和成熟NP的N-糖,并确定与衰老相关的模式。因此,我们从猪圆盘中的富含脊索细胞的NP中分离出N-聚糖,使用外切糖苷酶消化和亲水相互作用超高效液相色谱和质谱分析的组合方法对它们进行了表征。我们为每个年龄组分配了300多个单独的N-聚糖。此外,我们观察到大量的触角结构,半乳糖基化,岩藻糖基化,两个年龄组的唾液酸化。此外,正如我们的结果表明,随着年龄的增长,外臂岩藻糖基化增加和α(2,3)相关唾液酸化减少表明这些性状与年龄有关。最后,我们已经集中在一个广泛的表征的N-糖的丰富的细胞NP老化没有推断变性,仅描述特定于衰老的糖基化变化。我们的发现与其他研究相结合,表明NP的变性不涉及与衰老相同的过程。