糖皮质激素诱导的兔中性粒细胞中的一种磷脂酶A2抑制蛋白。
A phospholipase A2 inhibitory protein in rabbit neutrophils induced by glucocorticoids.
作者信息
Hirata F, Schiffmann E, Venkatasubramanian K, Salomon D, Axelrod J
出版信息
Proc Natl Acad Sci U S A. 1980 May;77(5):2533-6. doi: 10.1073/pnas.77.5.2533.
When rabbit peritoneal neutrophils were treated with glucocorticoids, their chemotactic response to stimulation by the chemoattractant fMet-Leu-Phe was markedly reduced. Preincubation of cells with glucocorticoids also decreased phospholipase A2 (phosphatide 2-acylhydrolase, EC 3.1.1.4) activity in situ as measured by the release of [1-14C]arachidonic acid previously incorporated into phospholipids. The inhibitory potencies of glucocorticoids on phospholipase A2 activity correlated well with their anti-inflammatory activities and their abilities to bind to glucocorticoid receptors. Inhibitors of RNA and protein synthesis suppressed the inhibitory effect of glucocorticoids on phospholipase A2 activity. Digestion of the glucocorticoid-treated cells by Pronase overcame the inhibitory activity. Phospholipase A2 activity induced by Ca2+ ionophore A23187 was not affected by Pronase treatment. Gel filtration of proteins from neutrophil membranes labeled with [3H]lysine showed an induction of protein(s) (about 40,000 daltons) after glucocorticoid treatment. This protein inhibited a partially purified pancreatic phospholipase A2 and reduced the peptide-initiated chemotactic response of neutrophils.
当兔腹膜中性粒细胞用糖皮质激素处理后，它们对趋化因子fMet-Leu-Phe刺激的趋化反应明显降低。用糖皮质激素对细胞进行预孵育，也会降低原位磷脂酶A2（磷脂2-酰基水解酶，EC 3.1.1.4）的活性，这是通过先前掺入磷脂中的[1-14C]花生四烯酸的释放来测量的。糖皮质激素对磷脂酶A2活性的抑制效力与其抗炎活性以及它们与糖皮质激素受体结合的能力密切相关。RNA和蛋白质合成抑制剂抑制了糖皮质激素对磷脂酶A2活性的抑制作用。用链霉蛋白酶消化经糖皮质激素处理的细胞可克服其抑制活性。Ca2+离子载体A23187诱导的磷脂酶A2活性不受链霉蛋白酶处理的影响。对用[3H]赖氨酸标记的中性粒细胞膜蛋白进行凝胶过滤显示，糖皮质激素处理后诱导了一种蛋白质（约40,000道尔顿）。这种蛋白质抑制部分纯化的胰磷脂酶A2，并降低中性粒细胞的肽引发的趋化反应。
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