Hou Yu-Chen, Hsu Chun-Sen, Yeh Chiu-Li, Chiu Wan-Chun, Pai Man-Hui, Yeh Sung-Ling
Institute of Nutrition and Health Sciences, Taipei Medical University, Taiwan, ROC.
J Nutr Biochem. 2005 Nov;16(11):700-4. doi: 10.1016/j.jnutbio.2005.04.007.
This study evaluated whether glutamine (GLN) concentration was related to endothelial surface molecule expression and the migration of polymorphonuclear neutrophils (PMNs) through endothelial cells (ECs) stimulated by arsenic. Human umbilical vein endothelial cells (HUVECs) and PMNs were treated with different GLN concentrations (0, 300, 600 and 1000 microM) for 24 h. After that, we stimulated HUVECs for 3 h with 0.5 microM arsenic, and PMNs were allowed to transmigrate to ECs for 2 h. HUVEC surface expressions of cell adhesion molecules and integrin (CD11b) and interleukin (IL)-8 receptor expressions on PMNs were measured. The transendothelial migration of PMNs was also analyzed. The results showed that cell adhesion molecule (CAM) and integrin expressions in arsenic groups were higher than in those without arsenic. Among the arsenic groups, the expression of CAMs on ECs and CD11b, and IL-8 receptor on PMNs was lowest with 0 microM compared with the other GLN concentrations. Vascular CAM-1 on ECs and CD11b on PMN expression were higher with 300 microM than with 600 and 1000 microM GLN. IL-8 secretions from ECs and PMNs were higher with 300 muM than with 600 and 1000 microM GLN, and this was consistent with the expression of the IL-8 receptor on PMNs. Polymorphonuclear neutrophil transmigration was significantly higher with 300 muM GLN than with other GLN concentrations. These results suggest that ECs and PMNs were activated after arsenic stimulation. Cell adhesion molecule expressions on ECs and PMNs were suppressed in the absence of GLN. A low GLN concentration comparable to catabolic conditions resulted in higher adhesion molecule expression and greater transendothelial migration of neutrophils. Glutamine administration at levels similar to or higher than physiological concentrations reduced IL-8 and adhesion molecule expression; PMN transmigration was also decreased after stimulation with arsenic.
本研究评估了谷氨酰胺（GLN）浓度是否与内皮表面分子表达以及多形核中性粒细胞（PMN）通过砷刺激的内皮细胞（EC）的迁移有关。将人脐静脉内皮细胞（HUVEC）和PMN用不同浓度的GLN（0、300、600和1000微摩尔）处理24小时。之后，用0.5微摩尔砷刺激HUVEC 3小时，并让PMN迁移至EC 2小时。检测HUVEC表面细胞粘附分子和整合素（CD11b）的表达以及PMN上白细胞介素（IL）-8受体的表达。还分析了PMN的跨内皮迁移。结果显示，砷处理组中细胞粘附分子（CAM）和整合素的表达高于未用砷处理的组。在砷处理组中，与其他GLN浓度相比，0微摩尔GLN时EC上CAMs、PMN上CD11b以及IL-8受体的表达最低。EC上血管细胞粘附分子-1（vascular CAM-1）和PMN上CD11b的表达在300微摩尔GLN时高于600和1000微摩尔GLN。EC和PMN分泌的IL-8在300微摩尔时高于600和1000微摩尔GLN，这与PMN上IL-8受体的表达一致。300微摩尔GLN时PMN的跨迁移明显高于其他GLN浓度。这些结果表明，砷刺激后EC和PMN被激活。在没有GLN的情况下，EC和PMN上细胞粘附分子的表达受到抑制。与分解代谢状态相当的低GLN浓度导致更高的粘附分子表达和中性粒细胞更大的跨内皮迁移。给予与生理浓度相似或更高水平的谷氨酰胺可降低IL-8和粘附分子的表达；用砷刺激后PMN的迁移也减少。
