Inherited human group IVA cytosolic phospholipase A2 deficiency abolishes platelet, endothelial, and leucocyte eicosanoid generation
Inherited human group IVA cytosolic phospholipase A2 deficiency abolishes platelet, endothelial, and leucocyte eicosanoid generation
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DOI：
10.1096/fj.15-275065
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发表时间：
2015-11-01
期刊：
影响因子：
4.8
通讯作者：
Warner, Timothy D.
中科院分区：
文献类型：
--
作者：
Kirkby, Nicholas S.;Reed, Daniel M.;Warner, Timothy D.
二十烷基类化合物是重要的血管调节因子，但支持其在心血管系统内产生的磷脂酶A(2)(PLA(2))亚型尚不完全清楚。为了解决这一问题，我们研究了来自IVA组胞浆磷脂酶A(2)(CPLA(2)α)纯合子功能丧失突变的两个兄弟姐妹的血小板、内皮细胞和白细胞。用气相色谱/质谱法测定分离的血管细胞以及血浆和尿液中产生的各种二十烷类化合物的水平。二十烷类化合物的释放数据与细胞功能的研究相结合。缺乏CPLA(2)α几乎消除了血小板(例如，血栓素A(2)，对照组20.5+/-1.4 ng/ml对患者0.1 ng/ml)和白细胞[例如，前列腺素E-2(2)，对照组21.9+/-7.4 ng/ml对患者1.9 ng/ml]中二十烷类化合物的合成，这与血小板活化受损和炎症反应增强有关。Cpla(2)α缺乏的内皮细胞显示前列腺素I-2的形成减少，但不是没有(前列环素：对照组956+/-422 pg/ml对患者196 pg/ml)，并为炎症做好准备。尿中前列腺素代谢产物受CPLA(2)α缺乏的选择性影响。例如，在缺乏CPLA(2)α的患者中，前列环素代谢产物显著减少(对照组的18.4%)，而PGE(2)代谢产物(对照组的77.8%)与健康志愿者水平相似。这些研究构成了一个明确的解释，证明了CPLA(2)α在人体循环中对二十烷类化合物的形成和细胞反应的基本作用。
Eicosanoids are important vascular regulators, but the phospholipase A(2) (PLA(2)) isoforms supporting their production within the cardiovascular system are not fully understood. To address this, we have studied platelets, endothelial cells, and leukocytes from 2 siblings with a homozygous loss-of-function mutation in group IVA cytosolic phospholipase A(2) (cPLA(2)alpha). Chromatography/mass spectrometry was used to determine levels of a broad range of eicosanoids produced by isolated vascular cells, and in plasma and urine. Eicosanoid release data were paired with studies of cellular function. Absence of cPLA(2)alpha almost abolished eicosanoid synthesis in platelets (e.g., thromboxane A(2), control 20.5 +/- 1.4 ng/ml vs. patient 0.1 ng/ml) and leukocytes [e.g., prostaglandin E-2 (PGE(2)), control 21.9 +/- 7.4 ng/ml vs. patient 1.9 ng/ml], and this was associated with impaired platelet activation and enhanced inflammatory responses. cPLA(2)alpha-deficient endothelial cells showed reduced, but not absent, formation of prostaglandin I-2 (prostacyclin; control 956 +/- 422 pg/ml vs. patient 196 pg/ml) and were primed for inflammation. In the urine, prostaglandin metabolites were selectively influenced by cPLA(2)alpha deficiency. For example, prostacyclin metabolites were strongly reduced (18.4% of control) in patients lacking cPLA(2)alpha, whereas PGE(2) metabolites (77.8% of control) were similar to healthy volunteer levels. These studies constitute a definitive account, demonstrating the fundamental role of cPLA(2)alpha to eicosanoid formation and cellular responses within the human circulation.