血小板内皮细胞黏附分子1、细胞间黏附分子3和CD44在体外淋巴管新生中的作用

EFFECTS OF ENDOTHELIAL ADHESION MOLECULE PECAM-1,ICAM-3 AND CD44 ON LYMPHANGIOGENESIS IN VITRO

目的 探讨内皮黏附分子血小板内皮细胞黏附分子 1(PECAM 1)、细胞间黏附分子 3(ICAM 3)和CD4 4对淋巴管新生的作用。 方法 用狗的胸导管分离和培养淋巴管内皮细胞。标记内皮细胞的PECAM 1、ICAM 3和CD4 4 ,在荧光显微镜和共聚焦激光扫描显微镜下观察。内皮细胞用肿瘤坏死因子 (TNF α)或脂多糖 (LPS)刺激后 ,再阻断PECAM 1、ICAM 3和CD4 4 ,作细胞计数和计算迁移率。制备三维凝胶淋巴管形成模型 ,观察管状结构的形成 ,测量其长度和面积 ,并在透射电镜下观察其特征。 结果 淋巴管内皮细胞表达PECAM 1、ICAM 3和CD4 4。在对照组以及TNF α和LPS刺激组 ,分别阻断PECAM 1、ICAM 3和CD4 4后 ,内皮细胞的迁移率降低 ,管样结构的长度和面积减少。阻断PECAM 1或CD4 4后 ,细胞的增殖数目降低 ,但阻断ICAM 3后细胞的增殖数目无明显变化。在半薄和超薄切片上 ,淋巴管内皮细胞形成的管状结构具有毛细淋巴管的形态特征。 结论 体外培养的淋巴管内皮细胞表达PECAM 1、ICAM 3和CD4 4 ,这些黏附分子参与了淋巴管内皮细胞的增殖、迁移和管腔形成等淋巴管新生过程。

Objective To investigate effects of endothelial adhesion molecule platelet endothelial cell odhesion molecule-1(PECAM-1),intercellular adhesion molecule-3(ICAM-3) and CD44 on lymphangiogenesis. Methods The lymphatic endothelial cells of the canine thoracic ducts were isolated and incubated.PECAM-1,ICAM-3 and CD44 on the lymphatic endothelial cells were labeled and visualized under fluorescence microscope and confocal laser scanning microscope.The endothelial cells stimulated by TNF-α or LPS were treated with the blocking antibodies against PECAM-1, ICAM-3 and CD44 respectively.The proliferation and migration of cells were determined with cell counting. The three-dimensional collagen gel model of lymphangiogenesis was prepared, and then the tube formation was viewed. The total length and area of the tubes formed from lymphatic endothelial cells were measured and their characteristics were examined with a transmission electron microscope. Results PECAM-1, ICAM-3 and CD44 were expressed on the lymphatic endothelial cells. In the control, TNF-α and LPS groups, the percentage of the migrated cells decreased and the total length and area of the tubes reduced after PECAM-1, ICAM-3 and CD44 of the cells were blocked respectively. The proliferated cells reduced after PECAM-1 or CD44 of the cells were blocked. However, there were no significant changes in the numbers of proliferated cells when ICAM-3 of the cells was blocked. In the semi-ultrathin and ultrathin sections, the tube structures formed by lymphatic endothelial cells were similar to lymphatic capillary.Conclusion PECAM-1, ICAM-3 and CD44 are expressed on the cultured lymphatic endothelial cells. These adhesion molecules are involved in lymphangiogenesis that includes proliferation, migration and tube formation of endothelial cells.