Enomoto Hiroyuki, Inoki Isao, Komiya Koichiro, Shiomi Takayuki, Ikeda Eiji, Obata Ken-ichi, Matsumoto Hideo, Toyama Yoshiaki, Okada Yasunori
Department of Pathology, School of Medicine, Keio University, Tokyo, Japan.
Am J Pathol. 2003 Jan;162(1):171-81. doi: 10.1016/s0002-9440(10)63808-4.
To assess the possible involvement of vascular endothelial growth factor (VEGF) in the pathology of osteoarthritic (OA) cartilage, we examined the expression of VEGF isoforms and their receptors in the articular cartilage, and the effects of VEGF on the production of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in OA chondrocytes. Reverse transcriptase-polymerase chain reaction analyses demonstrated that mRNAs for three VEGF isoforms (VEGF(121), VEGF(165), and VEGF(189)) are detectable in all of the OA and normal (NOR) cartilage samples. However, the mRNA expression of their receptors (VEGFR-1 = Flt-1, VEGFR-2 = KDR and neuropilin-1) was recognized only in the OA samples. The protein expression of VEGFR-1 and VEGFR-2 in OA chondrocytes was also demonstrated by immunohistochemistry of the OA cartilage tissue and cultured OA chondrocytes. In situ hybridization and immunohistochemistry indicated that VEGF is expressed in the chondrocytes in the superficial and transitional zones of OA cartilage. A linear correlation was obtained between VEGF immunoreactivity and Mankin scores in the cartilage (r = 0.906, P < 0.001). The production levels of VEGF determined by enzyme-linked immunosorbent assay were significantly 3.3-fold higher in OA than in NOR samples (P < 0.001). Among MMP-1, -2, -3, -7, -8, -9, and -13, TIMP-1 and -2 measured by their sandwich enzyme immunoassay systems, the production of MMP-1 and MMP-3 but not TIMP-1 or TIMP-2 was significantly enhanced by the treatment of cultured OA chondrocytes with VEGF (P < 0.05), whereas no such effect was obtained with cultured NOR chondrocytes. These results demonstrate that VEGF and its receptors are expressed in OA cartilage, and suggest the possibility that VEGF is implicated for the destruction of OA articular cartilage through the increased production of MMPs.
为评估血管内皮生长因子（VEGF）在骨关节炎（OA）软骨病理过程中可能的作用，我们检测了VEGF亚型及其受体在关节软骨中的表达，以及VEGF对OA软骨细胞中基质金属蛋白酶（MMPs）和金属蛋白酶组织抑制剂（TIMPs）产生的影响。逆转录聚合酶链反应分析表明，在所有OA和正常（NOR）软骨样本中均可检测到三种VEGF亚型（VEGF(121)、VEGF(165)和VEGF(189)）的mRNA。然而，仅在OA样本中识别出其受体（VEGFR-1 = Flt-1、VEGFR-2 = KDR和神经纤毛蛋白-1）的mRNA表达。OA软骨组织和培养的OA软骨细胞的免疫组织化学也证实了OA软骨细胞中VEGFR-1和VEGFR-2的蛋白表达。原位杂交和免疫组织化学表明，VEGF在OA软骨表层和过渡区的软骨细胞中表达。软骨中VEGF免疫反应性与Mankin评分之间存在线性相关性（r = 0.906，P < 0.001）。酶联免疫吸附测定法测定的OA中VEGF产生水平显著高于NOR样本，为其3.3倍（P < 0.001）。在用夹心酶免疫测定系统检测的MMP-1、-2、-3、-7、-8、-9和-13、TIMP-1和-2中，用VEGF处理培养的OA软骨细胞可显著增强MMP-1和MMP-3的产生，但不影响TIMP-1或TIMP-2的产生（P < 0.05），而培养的NOR软骨细胞未出现这种效应。这些结果表明VEGF及其受体在OA软骨中表达，并提示VEGF可能通过增加MMPs的产生参与OA关节软骨的破坏。
