STUDIES ON THE REGULATION AND LOCALIZATION OF 5-LIPOXYGENASE IN HUMAN B-LYMPHOCYTES
STUDIES ON THE REGULATION AND LOCALIZATION OF 5-LIPOXYGENASE IN HUMAN B-LYMPHOCYTES
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DOI：
10.1111/j.1432-1033.1995.tb20778.x
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发表时间：
1995-08-15
期刊：
影响因子：
--
通讯作者：
CLAESSON, HE
中科院分区：
文献类型：
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作者：
JAKOBSSON, PJ;SHASKIN, P;CLAESSON, HE
从B细胞型慢性淋巴细胞白血病患者（B-CLL细胞）或人扁桃体中分离的刺激B淋巴细胞产生与多形核粒细胞相似量的白三烯（LT）B-4和5-羟基二十碳四烯酸（5-HETE）。与完整的粒细胞或单核细胞不同，人B淋巴细胞需要钙离子载体、外源花生四烯酸和氧化环境以产生5-脂氧合酶产物。几种硫醇反应性化合物如N-乙基马来酰亚胺、甲硫基磺酸甲酯、偶氮二羧酸双[二甲基酰胺]（二酰胺）以及过氧化氢都被发现刺激细胞白三烯生物合成。逆转录-聚合酶链反应（RT-PCR）分析显示5-脂氧合酶、5-脂氧合酶激活蛋白（FLAP）和LTA（4）水解酶mRNA在B-CLL细胞中表达。Western blot分析显示B-CLL细胞膜上有一条与FLAP分子大小相对应的条带。此外，FLAP结合细胞白三烯生物合成抑制剂MK 886减少LTB（4）和5-HETE的形成。免疫细胞化学显示5-脂氧合酶主要定位于非活化的B-CLL细胞、扁桃体B淋巴细胞和单克隆B细胞的核内。相反，人外周T淋巴细胞和Jurkat细胞均未染色。这些结果表明，5-脂氧合酶及其产物在B淋巴细胞核中起作用。
Stimulated B-lymphocytes, isolated from patients with chronic lymphocytic leukemia of B-cell type (B-CLL cells) or from human tonsils, produced similar amounts of leukotriene (LT) B-4 and 5-hydroxyeicosatetraenoic acid (5-HETE) as polymorphonuclear granulocytes. Unlike intact granulocytes or monocytes, human B-lymphocytes require calcium ionophore, exogenous arachidonic acid and an oxidative environment in order to produce 5-lipoxygenase products. Several thiol-reactive compounds such as N-ethylmaleimide, methyl methanethiosulfonate, azodicarboxylic acid bis[dimethylamide] (diamide) as well as hydrogen peroxide were all found to stimulate cellular leukotriene biosynthesis. Reverse transcriptase (RT)-PCR analysis demonstrated the expression of 5-lipoxygenase, 5-lipoxygenase-activating protein (FLAP) and LTA(4) hydrolase mRNA in B-CLL cells. Western blot analysis demonstrated a band corresponding to the molecular size of FLAP in the B-CLL cell membrane. Furthermore, MK886, the FLAP-binding cellular leukotriene biosynthesis inhibitor, reduced both LTB(4) and 5-HETE formation. Immunocytochemistry showed that 5-lipoxygenase was mainly localized in the nuclei of non-activated B-CLL cells, tonsillar B-lymphocytes and monoclonal B-cells. In contrast, neither human peripheral T-lymphocytes nor Jurkat cells were stained. These results suggest that 5-lipoxygenase and its products function in the nucleus of B-lymphocytes.