BioSpectroscopie Translationnelle (BioSpecT), EA 7506, SFR CAP-Sante FED4231, Université de Reims Champagne-Ardenne, UFR de Pharmacie, 51 rue Cognacq-Jay, 51096, Reims, cedex, France.
Sci Rep. 2019 May 13;9(1):7280. doi: 10.1038/s41598-019-43636-2.
Type I Collagen is one of the most abundant proteins of the extracellular matrix of the most organs. During chronological aging or in diseases, type I collagen undergoes biochemical and structural changes which can impact biomechanical and physiological properties of organs. In this study, we have investigated the age-related changes in the molecular organization of type I collagen in rat tails tendon using polarized Raman spectroscopy. Our results show that Amide I, amide III as well as the bands related to proline and hydroxyproline are highly sensitive to polarization and age-related. On the other hand, 1453 and 1270 cm do not show any preferential orientation. Depolarization and anisotropic ratios were used to provide information about the changes in orientation of collagen fibers with aging. The anisotropy degree of Raman bands increase from adult to old collagen, indicating a higher collagen fibers alignment to the fascicle backbone axis in old tendons, and consequently a higher straightness of collagen fibers. These data were correlated to those obtained using polarized second harmonic generation technique. Polarized Raman mapping showed a more homogeneous spatial distribution of collagen fibers alignment to the fascicle axis in old tendon. This confirms a higher straightness of collagen fiber with aging.
I 型胶原蛋白是大多数器官细胞外基质中最丰富的蛋白质之一。在正常衰老或疾病过程中，I 型胶原蛋白会发生生化和结构变化，从而影响器官的生物力学和生理特性。在这项研究中，我们使用偏振拉曼光谱研究了大鼠尾腱中 I 型胶原蛋白的分子组织随年龄的变化。结果表明，酰胺 I、酰胺 III 以及与脯氨酸和羟脯氨酸相关的谱带对偏振和年龄具有高度敏感性。另一方面，1453 和 1270cm 处没有表现出任何优先取向。退偏和各向异性比用于提供有关胶原蛋白纤维随年龄变化的取向信息。随着年龄的增长，拉曼带的各向异性度增加，这表明老年肌腱中胶原蛋白纤维与束状纤维主干轴的排列更加一致，因此胶原蛋白纤维更加直。这些数据与使用偏振二次谐波产生技术获得的数据相关。偏振拉曼映射显示，老年肌腱中胶原蛋白纤维与束状纤维轴的空间分布更加均匀。这证实了随着年龄的增长，胶原蛋白纤维的直度增加。
