Galectin-3 surface expression on human adult chondrocytes:: a potential substrate for collagenase-3
Galectin-3 surface expression on human adult chondrocytes:: a potential substrate for collagenase-3
复制标题
DOI：
10.1136/ard.2003.007229
复制
发表时间：
2004-06-01
影响因子：
27.4
通讯作者：
Reboul, P
中科院分区：
文献类型：
--
作者：
Guévremont, M;Martel-Pelletier, J;Reboul, P
工作背景：Galectin-3是一种存在于成熟和早期肥大软骨细胞中的凝集素，骨关节炎（osteoarthritic，OA）软骨细胞可重新表达肥大标志物。目的：研究Galectin-3在成人软骨细胞中的合成、亚细胞定位以及Galectin-3被胶原酶-1和-3切割的可能性。采用免疫组化和真实的实时聚合酶链反应（PCR）检测正常和OA软骨中Galectin-3的表达。通过亚细胞分级分离、免疫细胞学和流式细胞术对其定位进行了研究。结果：与正常软骨相比，半乳糖凝集素-3在OA软骨中的表达增加了2.4倍（p< 0.05，n = 5）和3倍（p < 0.003，n = 6）。在成人软骨细胞中，半乳糖凝集素-3被发现在细胞质和膜富集级分。免疫细胞学和流式细胞术均证实软骨细胞表面存在半乳糖凝集素-3。整合素β 1和半乳糖凝集素3在软骨细胞表面的表达之间存在很强的相关性。此外，胶原酶-3以比胶原酶-1更高的活性切割半乳糖凝集素-3。所产生的蛋白水解位点是相同的明胶酶A和B。结论：半乳糖凝集素3可能发挥的一部分，在OA，有两个角色，一个细胞内，尚未确定，另一个在细胞表面，可能与软骨细胞和软骨基质的相互作用。
Background: Galectin-3 is a lectin detected in mature and early hypertrophic chondrocytes; osteoarthritic (OA) chondrocytes can re-express hypertrophic markers.Objective: To investigate the synthesis and subcellular localisation of galectin-3 in adult chondrocytes as well as the possibility of cleavage of galectin-3 by collagenase-1 and -3.Methods: Galectin-3 was assessed by immunohistochemistry and real time polymerase chain reaction (PCR) in normal and OA cartilage. Its localisation was investigated by subcellular fractionation, immunocytology, and flow cytometry. Proteolysis of galectin-3 by collagenase-1 and -3 was determined by in vitro assay.Results: Galectin-3 expression was increased 2.4-fold as measured by reverse transcriptase (RT)-PCR (p< 0.05, n = 5) and threefold by immunohistochemistry (p< 0.003 n = 6) in OA cartilage compared with normal cartilage. In adult chondrocytes, galectin-3 was found in the cytosol and membrane enriched fractions. Both immunocytology and flow cytometry confirmed the presence of galectin-3 at the surface of chondrocytes. A strong correlation was found between integrin-beta1 and galectin-3 expression at the surface of chondrocytes. Moreover, collagenase-3 cleaved galectin-3 with a higher activity than collagenase-1. The proteolysed sites generated were identical to those produced by gelatinases A and B.Conclusion: Galectin-3 may play a part in OA, having two roles, one intracellular and not yet identified, and another at the cell surface, possibly related to the interaction of chondrocytes and the cartilage matrix.