Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, People's Republic of China.
Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, People's Republic of China.
Calcif Tissue Int. 2021 Aug;109(2):179-189. doi: 10.1007/s00223-021-00834-3. Epub 2021 Mar 13.
This study aims to investigate how biochemical composition in subchondral bone (SB) relates to the sulfated glycosaminoglycan (sGAG) content of articular cartilage (AC) in the knee joint of guinea pigs from the early to moderate osteoarthritis (OA). Male Dunkin Hartley strain guinea pigs were grouped according to age (1, 3, 6, and 9 months, with 10 guinea pigs in each group). The biochemical properties of the AC and SB in the tibial plateau of the guinea pigs were determined through histology and Raman spectroscopy, respectively. Furthermore, the microstructures of the SB were investigated using micro-computed tomography (micro-CT) and histology. Increased thickness and bone mineral density (BMD) and decreased porosity were observed in the subchondral plate (SP) with the progression of spontaneous OA, accompanied by a decreasing trend in sGAG integrated optical density (IOD) of AC. Compared with the changes in the microstructure of subchondral bone, the content of sGAG was more correlated to the changes in the mineral/matrix ratio of subchondral bone. The mineralization of the matrix was significantly correlated to the content of sGAG compared with crystallinity/maturity and Type B carbonate substitution. PO ν1/Amide III was more correlated to the content of sGAG than PO ν1/Amide I, PO ν1/CH wag during the progression of spontaneous osteoarthritis. This study demonstrated that the mineralization of subchondral bone plays a crucial role in the pathogenesis of OA. Future studies may access to the mineralization of subchondral bone in addition to its microstructure in the study for pathogenesis and early diagnosis of osteoarthritis.
本研究旨在探讨幼年至中年豚鼠膝关节软骨下骨（SB）的生化组成与关节软骨（AC）中硫酸糖胺聚糖（sGAG）含量之间的关系。雄性 Dunkin Hartley 品系豚鼠根据年龄（1、3、6 和 9 个月，每组 10 只）分组。通过组织学和拉曼光谱分别测定豚鼠胫骨平台 AC 和 SB 的生化特性。此外，还使用微计算机断层扫描（micro-CT）和组织学研究了 SB 的微观结构。随着自发性 OA 的进展，观察到软骨下板（SP）的厚度和骨矿物质密度（BMD）增加，孔隙率降低，同时 AC 的 sGAG 积分光密度（IOD）呈下降趋势。与软骨下骨微观结构的变化相比，sGAG 的含量与软骨下骨矿物质/基质比值的变化更相关。与结晶度/成熟度和 B 型碳酸盐取代相比，基质的矿化与 sGAG 的含量显著相关。与 PO ν1/Amide I 相比，PO ν1/Amide III 与 sGAG 的含量更相关，在自发性骨关节炎的进展过程中，PO ν1/CH wag。本研究表明，软骨下骨的矿化在 OA 的发病机制中起着关键作用。未来的研究可能会在研究 OA 的发病机制和早期诊断时，除了研究软骨下骨的微观结构外，还会研究软骨下骨的矿化。
