地塞米松处理小鼠胸腺细胞中的磷脂酶A2抑制活性——脂皮质素的可能作用

Phospholipase A2 inhibitory activity in thymocytes of dexamethasone-treated mice--possible implication of lipocortins.

作者信息

Errasfa M, Rothhut B, Russo-Marie F

机构信息

Unité de Pharmacologie Cellulaire, Institut Pasteur/INSERM U 285, Paris, France.

出版信息

Biochem Biophys Res Commun. 1989 Feb 28;159(1):53-60. doi: 10.1016/0006-291x(89)92403-0.

DOI:10.1016/0006-291x(89)92403-0

PMID:2522304

Abstract

The cellular phospholipase A2 activity of mouse thymocytes was estimated in vitro by the release of [3H]-Arachidonic acid from labeled and calcium ionophore A23187-stimulated cells. This activity was decreased in thymocytes from dexamethasone-treated mice. Thus, the presence of phospholipase A2 inhibitory proteins in mouse thymus was investigated. Three main proteins (36 kDa I, 36 kDa II, 73 kDa) were purified. These proteins were able to inhibit both phospholipase A2 in vitro, and the release of [3H]-Arachidonic acid from labeled and stimulated mouse thymocytes. Biochemical analysis revealed that the three proteins were lipocortin-like proteins. Our results show that in vivo dexamethasone treatment induces a phospholipase A2 inhibitory activity in mouse thymus, such an inhibition can be reproduced on isolated thymocytes by purified thymic lipocortins, known as glucocorticosteroid-inducible proteins.

摘要

通过检测标记的、经钙离子载体A23187刺激的细胞中[3H] - 花生四烯酸的释放情况，在体外评估小鼠胸腺细胞的细胞磷脂酶A2活性。地塞米松处理的小鼠胸腺细胞中该活性降低。因此，对小鼠胸腺中磷脂酶A2抑制蛋白的存在情况进行了研究。纯化出三种主要蛋白（36 kDa I、36 kDa II、73 kDa）。这些蛋白在体外既能抑制磷脂酶A2，又能抑制标记的、受刺激的小鼠胸腺细胞中[3H] - 花生四烯酸的释放。生化分析表明这三种蛋白是脂皮质素样蛋白。我们的结果表明，体内地塞米松处理可诱导小鼠胸腺产生磷脂酶A2抑制活性，纯化的胸腺脂皮质素（即糖皮质激素诱导蛋白）可在分离的胸腺细胞上重现这种抑制作用。