Department of Orthopaedic Surgery, Georgia Reagents University, Augusta, GA 30912, USA.
BMC Musculoskelet Disord. 2014 Jan 8;15:9. doi: 10.1186/1471-2474-15-9.
Nutrient levels are known to influence the development of osteoarthritis (OA), presumably by modulating levels of matrix biosynthesis and degradation. These processes may be affected by ascorbic acid (AA), an antioxidant which acts as a cofactor for numerous biochemical reactions and is essential for post-translational modifications of collagen. In this study we examined the expression of SVCT2, the only known Sodium coupled vitamin C transporter isoform present in articular cartilage, in human articular cartilage explants derived from both normal and osteoarthritis articular cartilage.
OA1 and OA3 human articular cartilage was carefully dissected and macroscopically graded for degeneration via the Collins scale. The tissue samples were histologically examined by Hematoxylin and Eosin and Safranin O and Fast Green staining. SVCT2 expression analysis was performed at mRNA level by quantitative real time PCR and at a protein level by immunohistochemistry.
Our quantitative real time PCR showed marked variation in the expression of SVCT2 in human osteoarthritic articular cartilage. SVCT2 expression was significantly down-regulated (p = 0.0001) in the Collins grade 3 (OA3) compared to Collins grade 1 (OA1) tissue. Furthermore, slides stained with fluorescent antibodies to SVCT2 demonstrated greatly reduced fluorescence for the SVCT2 transporter on the chondrocyte plasma membrane in the osteoarthritic tissue samples.
These findings demonstrate that the expression of SVCT2 transporter is significantly altered in human osteoarthritic tissues (OA3). The modulation of this transporter could therefore potentially influence the prevention, management and treatment of osteoarthritis.
已知营养水平会通过调节基质生物合成和降解水平来影响骨关节炎 (OA) 的发展。这些过程可能会受到抗坏血酸 (AA) 的影响，AA 是一种抗氧化剂，作为许多生化反应的辅助因子，并且是胶原蛋白翻译后修饰所必需的。在这项研究中，我们检查了 SVCT2 的表达，SVCT2 是关节软骨中唯一已知的与钠离子偶联的维生素 C 转运体同工型。
仔细解剖 OA1 和 OA3 人类关节软骨，并通过 Collins 评分对退变进行宏观分级。组织样本通过苏木精和伊红以及番红 O 和固绿染色进行组织学检查。通过定量实时 PCR 进行 SVCT2 表达的 mRNA 水平分析，并通过免疫组织化学进行蛋白质水平分析。
我们的定量实时 PCR 显示，SVCT2 在人类骨关节炎关节软骨中的表达存在明显差异。与 Collins 分级 1 (OA1) 组织相比，SVCT2 在 Collins 分级 3 (OA3) 中表达显著下调 (p = 0.0001)。此外，用荧光抗体对 SVCT2 染色的幻灯片显示，在骨关节炎组织样本中，SVCT2 转运体在软骨细胞质膜上的荧光大大降低。
这些发现表明，SVCT2 转运体在人类骨关节炎组织 (OA3) 中的表达明显改变。因此，这种转运体的调节可能会潜在地影响骨关节炎的预防、管理和治疗。
