Scharf Brian, Clement Cristina C, Yodmuang Supansa, Urbanska Aleksandra M, Suadicani Sylvia O, Aphkhazava David, Thi Mia M, Perino Giorgio, Hardin John A, Cobelli Neil, Vunjak-Novakovic Gordana, Santambrogio Laura
Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
Chem Biol. 2013 Jul 25;20(7):922-34. doi: 10.1016/j.chembiol.2013.06.006.
Aging-related oxidative stress has been linked to degenerative modifications in different organs and tissues. Using redox proteomic analysis and illustrative tandem mass spectrometry mapping, we demonstrate oxidative posttranslational modifications in structural proteins of intervertebral discs (IVDs) isolated from aging mice. Increased protein carbonylation was associated with protein fragmentation and aggregation. Complementing these findings, a significant loss of elasticity and increased stiffness was measured in fibrocartilage from aging mice. Studies using circular dichroism and intrinsic tryptophan fluorescence revealed a significant loss of secondary and tertiary structures of purified collagens following oxidation. Collagen unfolding and oxidation promoted both nonenzymatic and enzymatic degradation. Importantly, induction of oxidative modification in healthy fibrocartilage recapitulated the biochemical and biophysical modifications observed in the aging IVD. Together, these results suggest that protein carbonylation, glycation, and lipoxidation could be early events in promoting IVD degenerative changes.
与衰老相关的氧化应激与不同器官和组织的退行性改变有关。通过氧化还原蛋白质组学分析和示例性串联质谱图谱，我们证明了从衰老小鼠分离的椎间盘（IVD）结构蛋白中的氧化翻译后修饰。蛋白质羰基化增加与蛋白质片段化和聚集有关。作为这些发现的补充，在衰老小鼠的纤维软骨中测量到弹性显著丧失和硬度增加。使用圆二色性和内在色氨酸荧光的研究表明，氧化后纯化胶原蛋白的二级和三级结构显著丧失。胶原蛋白的展开和氧化促进了非酶促和酶促降解。重要的是，在健康纤维软骨中诱导氧化修饰重现了在衰老IVD中观察到的生化和生物物理修饰。总之，这些结果表明蛋白质羰基化、糖基化和脂氧化可能是促进IVD退行性变化的早期事件。
