LIPOXYGENASE PRODUCT FORMATION AND CELL-ADHESION DURING NEUTROPHIL GLOMERULAR ENDOTHELIAL-CELL INTERACTION
LIPOXYGENASE PRODUCT FORMATION AND CELL-ADHESION DURING NEUTROPHIL GLOMERULAR ENDOTHELIAL-CELL INTERACTION
复制标题
DOI：
10.1152/ajprenal.1995.268.1.f1
复制
发表时间：
1995-01-01
期刊：
影响因子：
--
通讯作者：
MARSDEN, PA
中科院分区：
文献类型：
--
作者：
BRADY, HR;LAMAS, S;MARSDEN, PA
在多形核白细胞（PMN）和微血管肾小球内皮细胞（GEN）的离子载体刺激的共孵育中监测白三烯（LT）和脂氧素（LX）水平，以确定细胞-细胞相互作用期间产生的脂氧合酶（LO）产物的概况，以及在这种情况下跨细胞途径对LO产物生物合成的相对贡献。通过反相高效液相色谱和放射免疫测定，LTB（4）和LTC（4）是形成的主要产物。与PMN单独孵育相比，PMN和GEN共同孵育的LTB（4）和LTC（4）水平分别增加了23%和185%。与此相反，LXA（4）和LXB（4）水平在GEN存在下没有变化。这些数据表明GEN利用PMN衍生的LTA（4）产生LT。与这一假设一致，如果PMN被人粒细胞-巨噬细胞集落刺激因子（GM-CSF）激活，LT的生物合成增强，GM-CSF是一种细胞因子，可通过激活PMN增加LTA（4）的生物合成。LT对中性粒细胞粘附GEN的影响也进行了评估，因为粘附似乎是急性肾小球肾炎中中性粒细胞募集的关键事件。在基础条件下，LTB（4）通过PMN导向的CD 11/CD 18依赖性机制引起低水平的粘附。预先用GM-CSF致敏PMN或用肿瘤坏死因子-α（TNF）激活GEN可显著增强粘附水平。在这方面，LTB（4）与补体成分C5 a、血小板活化因子（PAF）和白细胞介素-8（IL-8）一样有效，其他介质有助于PMN在炎症肾小球中的截留。LTC（4）也通过CD 11/CD 18依赖性机制引起PMN-GEN粘附，但与LTB（4）相反，LTC（4）通过与GEN的作用。LTC（4）的这种作用似乎至少部分是通过GEN诱导PAF合成介导的。有趣的是，在用15（S）-羟基二十碳四烯酸重塑PMN磷脂后，LT诱导的PMN-GEN粘附明显减弱，一种15-LO的产物，其在某些实验性和人类炎症性疾病中被认为是抗炎类二十烷酸。综上所述，这些结果提供了进一步的证据，1）跨细胞生物合成途径可以放大炎症介质的概况，从而有助于急性肾小球肾炎中的白细胞募集和2）5-LO和15-LO途径的产物可以在体内肾小球炎症期间对PMN运输发挥相反的作用。
Leukotriene (LT) and lipoxin (LX) levels were monitored in ionophore-stimulated coincubations of polymorphonuclear neutrophils (PMN) and microvascular kidney glomerular endothelial cells (GEN) to determine the profile of Lipoxygenase (LO) products generated during cell-cell interactions and the relative contributions of transcellular pathways to LO product biosynthesis in this setting. LTB(4) and LTC(4) were the major products formed, as determined by reverse-phase high-performance liquid chromatography and radioimmunoassay. LTB(4) and LTC(4) levels were increased by 23 and 185%, respectively, in coincubations of PMN and GEN, compared with incubations of PMN alone. In contrast, LXA(4) and LXB(4) levels were not changed in the presence of GEN. These data suggested that GEN utilize PMN-derived LTA(4) to generate LT. In keeping with this hypothesis, LT biosynthesis was enhanced if PMN were primed with human granulocyte-macrophage colony-stimulating factor (GM-CSF), a cytokine that augments LTA(4) biosynthesis by activated PMN. The influence of LT on PMN adhesion to GEN was also assessed, since adhesion appears to be a pivotal event in recruitment of PMN in acute glomerulonephritis. Under basal conditions, LTB(4) provoked low levels of adhesion via a PMN-directed CD11/CD18-dependent mechanism. The level of adhesion was markedly enhanced by prior priming of PMN with GM-CSF or activation of GEN with tumor necrosis factor-alpha (TNF). LTB(4) was as potent in this regard as the complement component C5a, platelet-activating factor (PAF), and interleukin-8 (IL-8), other mediators that contribute to the entrapment of PMN in inflamed glomeruli. LTC(4) also provoked PMN-GEN adhesion via a CD11/CD18-dependent mechanism, but, in contrast to LTB(4), via actions with GEN. This action of LTC(4) appeared to be mediated, at least in part, by induction of PAF synthesis by GEN. Interestingly, LT-induced PMN-GEN adhesion was markedly attenuated following remodeling of PMN phospholipids with 15(S)-hydroxyeicosatetraenoic acid, a product of 15-LO, which has been implicated as an anti-inflammatory eicosanoid in some experimental and human inflammatory diseases. Taken together, these results provide further evidence that 1) transcellular biosynthetic pathways may amplify the profiles of inflammatory mediators and thereby contribute to leukocyte recruitment in acute glomerulonephritis and 2) that products of the 5-LO and 15-LO pathways may exert opposing actions on PMN trafficking during glomerular inflammation in vivo.