Cartwright P H, Ilchyshyn A, Ilderton E, Yardley H J
Department of Dermatology, North Staffordshire Hospital Centre, Stoke-on-Trent, U.K.
Br J Dermatol. 1988 Mar;118(3):333-8. doi: 10.1111/j.1365-2133.1988.tb02425.x.
Phospholipase A2 activity is raised in non-lesional psoriatic epidermis compared with normal epidermis. It has been shown that the activity of this enzyme is controlled by an inhibitory protein the inhibitory effect of which is increased by dephosphorylation. Treatment of epidermal extracts with alkaline phosphatase reduced the phospholipase A2 activity, both in normal and in lesion-free psoriatic epidermis. Inclusion of pyrophosphate, a protein phosphatase inhibitor, in the homogenizing medium caused the activity of phospholipase A2 in epidermal extracts from normal and lesion-free epidermis to be raised to the same high level. These results are consistent with the hypothesis that the raised phospholipase A2 activity in psoriatic epidermis is due to hyperphosphorylation of an endogenous inhibitor as a result of defective control of a phosphorylation/dephosphorylation mechanism. The relevance of these findings to other work is discussed.
与正常表皮相比，非皮损性银屑病表皮中的磷脂酶A2活性升高。研究表明，该酶的活性受一种抑制蛋白的控制，该抑制蛋白的抑制作用通过去磷酸化增强。用碱性磷酸酶处理表皮提取物可降低正常和无皮损银屑病表皮中的磷脂酶A2活性。在匀浆介质中加入焦磷酸（一种蛋白磷酸酶抑制剂），可使正常和无皮损表皮的表皮提取物中磷脂酶A2的活性升高至相同的高水平。这些结果与以下假设一致：银屑病表皮中磷脂酶A2活性升高是由于磷酸化/去磷酸化机制控制缺陷导致内源性抑制剂过度磷酸化。讨论了这些发现与其他研究工作的相关性。
