Matsuo M, Nishida K, Yoshida A, Murakami T, Inoue H
Department of Orthopaedic Surgery, Okayama University Medical School, Japan.
Acta Med Okayama. 2001 Dec;55(6):333-40. doi: 10.18926/AMO/32000.
To clarify the involvement of the caspase family in the pathway of NO-induced chondrocyte apoptosis, osteoarthritis (OA) cartilage obtained from 8 patients undergoing total hip arthroplasty were used for histopathological study. Cartilage samples taken from non-fibrillated areas of femoral head resected during surgery for femoral neck fracture were used for comparison. DNA fragmentation of chondrocytes was detected by the nick end-labeling (TUNEL) method. Apoptosis was further confirmed by transmission electron microscopy. The distributions of nitrotyrosine (NT), caspase-3, and -9 were examined immunohistochemically. The populations of apoptotic as well as NT-, caspase-3-, and -9-positive cells were quantified by counting the number of cells in the superficial, middle, and deep layers, respectively. The TUNEL-positive cells were observed primarily in superficial proliferating chondrocytes, clustering chondrocytes, and deep-layer chondrocytes of OA cartilage. Few positive cells were seen in the proliferating chondrocytes in the middle layer. Positive reactions for caspase-3 and -9 were observed in chondrocytes in similar areas. Histological OA grade showed significant correlations with the mean populations of apoptotic chondrocytes (% apoptosis) over the 3 areas. The populations of NT-positive cells (% NT) over the same areas also showed significant correlation with OA grade. Positivity for caspase-3 closely correlated with the OA grade, % apoptosis and %NT. It was concluded that caspase-3 and -9 could play a role in NO-induced chondrocyte apoptosis in OA cartilage.
为阐明半胱天冬酶家族在一氧化氮（NO）诱导的软骨细胞凋亡途径中的作用，我们采用组织病理学研究方法，对8例行全髋关节置换术患者的骨关节炎（OA）软骨进行了研究。同时，选取股骨颈骨折手术中切除的股骨头非纤维区域的软骨样本作为对照。采用缺口末端标记法（TUNEL）检测软骨细胞的DNA片段化情况。通过透射电子显微镜进一步证实细胞凋亡。采用免疫组织化学方法检测硝基酪氨酸（NT）、半胱天冬酶-3和-9的分布情况。分别通过计数表层、中层和深层细胞数量，对凋亡细胞以及NT、半胱天冬酶-3和-9阳性细胞的数量进行定量分析。TUNEL阳性细胞主要见于OA软骨的表层增殖软骨细胞、聚集软骨细胞和深层软骨细胞。中层增殖软骨细胞中未见阳性细胞。在相似区域的软骨细胞中观察到半胱天冬酶-3和-9的阳性反应。组织学OA分级与三个区域凋亡软骨细胞的平均数量（凋亡率）显著相关。相同区域NT阳性细胞数量（NT率）也与OA分级显著相关。半胱天冬酶-3阳性与OA分级、凋亡率和NT率密切相关。研究得出结论，半胱天冬酶-3和-9可能在OA软骨中NO诱导的软骨细胞凋亡中发挥作用。
