Human osteoarthritic cartilage matrix vesicles generate both calcium pyrophosphate dihydrate and apatite in vitro
Human osteoarthritic cartilage matrix vesicles generate both calcium pyrophosphate dihydrate and apatite in vitro
复制标题
DOI：
10.1007/s002239900523
复制
发表时间：
1998-09-01
影响因子：
4.2
通讯作者：
Ryan, L
中科院分区：
文献类型：
--
作者：
Derfus, B;Kranendonk, S;Ryan, L
骨关节炎 (OA) 关节中的钙晶体促进关节组织的酶促降解。基质囊泡为小鸡骨骺和成熟猪关节软骨中钙晶体的形成提供了巢穴。为了研究来自 OA 软骨的基质囊泡在生成病理晶体中的潜在作用，我们试图确定来自人 OA 软骨 (OAMV) 的囊泡是否可以矿化；我们对由此产生的矿物种类进行了表征。分离 OAMV 并检查碱性磷酸酶 (AP) 和核苷三磷酸焦磷酸水解酶 (NTPPPPH) 活性。在辐射生物矿化测定中测量了 OAMV ATP 依赖和独立矿化，并使用傅里叶变换红外光谱 (FTIR) 和补偿偏振光显微镜检查新形成的 OAMV 晶体。与先前表征的成熟猪关节软骨囊泡相比，OAMV AP 的平均比活性大约高 6 倍，NTPPPPH 活性低 11 倍。在 ATP 存在和不存在的情况下，OAMV 随着时间的推移逐渐沉淀 Ca-45。 ATP 依赖性测定中形成的矿物质的 FTIR 光谱与二水焦磷酸钙 (CPPD) 的标准光谱最相似。在没有 ATP 的情况下形成的 OAMV 矿物的 FTIR 光谱与磷灰石非常相似。这些数据支持以下假设：OAMV 可能形成退化软骨中发现的两种关键晶体的矿物相，并为基质囊泡在病理性关节软骨生物矿化中的作用提供进一步的证据。
Calcium crystals in osteoarthritic (OA) joints promote enzymatic degradation of articular tissues. Matrix vesicles provide a nidus for calcium crystal formation in chick epiphyseal and mature porcine articular cartilage. In order to examine a potential role for matrix vesicles from OA cartilage in generating pathologic crystals, we sought to determine whether vesicles derived from human OA cartilage (OAMV) could mineralize; and we characterized the resultant mineral species. OAMV were isolated and examined for alkaline phosphatase (AP) and nucleoside triphosphate pyrophosphohydrolase (NTPPPH) activity. OAMV ATP-dependent and independent mineralization were measured in a radiometric biomineralization assay, and newly formed OAMV crystals were examined using Fourier transform infrared spectroscopy (FTIR) and compensated polarized light microscopy. The mean specific activity of OAMV AP was approximately 6 times higher and NTPPPH activity 11 times lower than that of previously characterized, mature, porcine, articular cartilage vesicles. OAMV progressively precipitated Ca-45 over time both in the presence and absence of ATP. The FTIR spectra of mineral formed in ATP-dependent assays most closely resembled the standard spectrum for calcium pyrophosphate dihydrate (CPPD). The FTIR spectra of OAMV mineral formed in the absence of ATP closely resembled apatite. These data support the hypothesis that OAMV may form mineral phases of two key crystals found in degenerating cartilage and provide further evidence for the role of matrix vesicles in pathologic articular cartilage biomineralization.