Sultana C, Shen Y, Rattan V, Kalra V K
Department of Biochemistry and Molecular Biology, School of Medicine, University of Southern California, Los Angeles 90033, USA.
J Cell Physiol. 1996 Jun;167(3):477-87. doi: 10.1002/(SICI)1097-4652(199606)167:3<477::AID-JCP12>3.0.CO;2-1.
Studies have shown that, among lipoxygenase metabolites examined, 15(S)-hydroperoxy-5,8,11,13-eicosa-tetraenoic acid (15[S]-HPETE), at micromolar concentrations, selectively causes injury to cultured endothelial cells. We investigated whether physiologically relevant concentrations of lipoxygenase metabolites affected the expression of cell adhesion molecules (CAMs) involved in the adhesion of leukocytes and/or the accumulation of leukocytes in the vascular endothelium, these being the initial events in endothelial cell injury. Among lipoxygenase metabolites, 15(S)-HPETE and 12(S)-HETE, at nanomolar concentrations, induced surface expression of a subset of cell adhesion molecules (CAM), ICAM-1, ELAM-1, and VCAM-1, in human umbilical vein endothelial cells (HUVEC), which is associated with an increased binding activity of the transcription factor, NF-kappa B, to the consensus motif common to the CAM genes in the HUVEC nuclear extracts. Furthermore, 15(S)-HPETE (1 nM) caused a threefold increase in the rate of transendothelial migration of vitamin D3-differentiated HL-60 monocyte-like cells and showed a thirtyfold increase in the phosphorylation of PECAM-1, an adhesion molecule involved in endothelial cell-cell adhesion. Both an antibody to PECAM-1 and the protein kinase C inhibitor, GF 109203X, reduced 15(S)-HPETE-induced transmigration of monocyte-like HL-60 cells by approximately 75% and 85%, respectively. Treatment of HUVEC with a phosphatase inhibitor, calyculin A, augmented both the phosphorylation of PECAM-1 and transmigration of monocyte-like HL-60 cells induced by 15(S)-HPETE. Our results show that 15(S)-HPETE, at physiological concentrations, induced activation of protein kinase C in HUVEC and leads to the phosphorylation of PECAM-1, thus facilitating the migration of monocyte-like HL-60 cells across the endothelial cell monolayer. It is suggested that phosphorylation/dephosphorylation events in PECAM-1 are important in regulating the trafficking of monocytes across the endothelial cell monolayer.
研究表明，在所检测的脂氧合酶代谢产物中，微摩尔浓度的15(S)-氢过氧-5,8,11,13-二十碳四烯酸（15[S]-HPETE）可选择性地损伤培养的内皮细胞。我们研究了生理相关浓度的脂氧合酶代谢产物是否会影响参与白细胞黏附的细胞黏附分子（CAMs）的表达和/或白细胞在血管内皮中的聚集，这些是内皮细胞损伤的起始事件。在脂氧合酶代谢产物中，纳摩尔浓度的15(S)-HPETE和12(S)-HETE可诱导人脐静脉内皮细胞（HUVEC）中细胞黏附分子（CAM）子集ICAM-1、ELAM-1和VCAM-1的表面表达，这与转录因子NF-κB与HUVEC核提取物中CAM基因共同的共有基序的结合活性增加有关。此外，15(S)-HPETE（1 nM）使经维生素D3分化的HL-60单核细胞样细胞的跨内皮迁移速率增加了三倍，并使参与内皮细胞间黏附的黏附分子PECAM-1的磷酸化增加了三十倍。PECAM-1抗体和蛋白激酶C抑制剂GF 109203X分别使15(S)-HPETE诱导的单核细胞样HL-60细胞迁移减少了约75%和85%。用磷酸酶抑制剂花萼海绵诱癌素A处理HUVEC，可增强15(S)-HPETE诱导的PECAM-1磷酸化和单核细胞样HL-60细胞的迁移。我们的结果表明，生理浓度的15(S)-HPETE可诱导HUVEC中蛋白激酶C的激活，并导致PECAM-1的磷酸化，从而促进单核细胞样HL-60细胞穿过内皮细胞单层的迁移。提示PECAM-1中的磷酸化/去磷酸化事件在调节单核细胞穿过内皮细胞单层的运输中起重要作用。
