Vigl Benjamin, Zgraggen Claudia, Rehman Nadia, Banziger-Tobler Nadia E, Detmar Michael, Halin Cornelia
Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology, ETH Zurich, Wolfgang-Pauli Str. 10, CH-8093 Zurich, Switzerland.
Exp Cell Res. 2009 Jan 15;315(2):336-47. doi: 10.1016/j.yexcr.2008.10.020. Epub 2008 Oct 30.
Lymphatic vessels play an important role in tissue fluid homeostasis, intestinal fat absorption and immunosurveillance. Furthermore, they are involved in pathologic conditions, such as tumor cell metastasis and chronic inflammation. In comparison to blood vessels, the molecular phenotype of lymphatic vessels is less well characterized. Performing comparative gene expression analysis we have recently found that coxsackie- and adenovirus receptor (CAR) is significantly more highly expressed in cultured human, skin-derived lymphatic endothelial cells (LECs), as compared to blood vascular endothelial cells. Here, we have confirmed these results at the protein level, using Western blot and FACS analysis. Immunofluorescence performed on human skin confirmed that CAR is expressed at detectable levels in lymphatic vessels, but not in blood vessels. To address the functional significance of CAR expression, we modulated CAR expression levels in cultured LECs in vitro by siRNA- and vector-based transfection approaches. Functional assays performed with the transfected cells revealed that CAR is involved in distinct cellular processes in LECs, such as cell adhesion, migration, tube formation and the control of vascular permeability. In contrast, no effect of CAR on LEC proliferation was observed. Overall, our data suggest that CAR stabilizes LEC-LEC interactions in the skin and may contribute to lymphatic vessel integrity.
淋巴管在组织液稳态、肠道脂肪吸收和免疫监视中发挥着重要作用。此外，它们还参与病理状况，如肿瘤细胞转移和慢性炎症。与血管相比，淋巴管的分子表型特征尚不明确。通过进行比较基因表达分析，我们最近发现，与血管内皮细胞相比，柯萨奇病毒和腺病毒受体（CAR）在培养的人皮肤来源的淋巴管内皮细胞（LEC）中表达明显更高。在这里，我们使用蛋白质印迹和流式细胞术分析在蛋白质水平上证实了这些结果。对人皮肤进行的免疫荧光检测证实，CAR在淋巴管中以可检测的水平表达，但在血管中不表达。为了探讨CAR表达的功能意义，我们通过基于小干扰RNA（siRNA）和载体的转染方法在体外调节培养的LEC中CAR的表达水平。对转染细胞进行的功能测定表明，CAR参与LEC中的不同细胞过程，如细胞黏附、迁移、管形成和血管通透性的控制。相比之下，未观察到CAR对LEC增殖有影响。总体而言，我们的数据表明，CAR可稳定皮肤中LEC-LEC相互作用，并可能有助于淋巴管的完整性。
