Transmembrane Signaling System in Psoriatic Keratinocytes.

最近的证据表明，肌醇磷脂的降解是一个重要的跨膜信号系统，它由两种信号组成：二酰甘油(DAG)-蛋白激酶C信号和肌醇三磷酸钙++信号。该系统在银屑病过度增殖的角质形成细胞中被激活，这可能与其他跨膜信号系统的功能改变有关，如腺苷环化酶。研究表明，表皮腺苷环化酶受多种蛋白激酶C激活剂的调节，其中包括促进肿瘤的佛波酯。这种调节类似于银屑病受累的表皮。尽管发现经典的蛋白激酶C同工酶可被DAG激活，但在较高浓度下也可被Ca^&lt；++&gt；激活，但表皮的腺苷环化反应仅受DAG-蛋白激酶C信号的调节，而不受Ca^&lt；++&gt；信号的调节。我们的结果表明，表皮腺苷环化酶系统受蛋白激酶C的调节，这可能是黑木和C-Worker最近描述的一种新的钙不敏感的蛋白激酶C形式。

Recent evidence suggests that the breakdown of inositol phospholipids is an important transmembrane signalling system that is composed of two kinds of signals : the diacylglycerol (DAG) -protein kinase C signal, and the inositol trisphosphate - Ca^<++> signal. The system is activated in psoriatic hyperproliferative keratinocytes, which might be associated with the altered function of other transmembrane signaling systems such as the adenylate cyclase. The epidermal adenylate cyclase was shown to be modulated by various protein kinase C activators, which include tumor promoting phorbol esters. The modulation was similar to that of psoriatic involved epidermis. Despite the finding that the classical protein kinase C isozymes are activated by DAG and also by Ca^<++> at higher concentrations, the epidermal adenylate cyclase responses were modulated only by DAG-protein kinase C signal, but not by Ca^<++> signal. Our results indicate that the epidermal adenylate cyclase system is modulated by protein kinase C, which might be the novel Ca^<++>insensitive form of protein kinase C recently described by Kuroki and C -workers.