Heng M C, Song M K, Heng M K
Division of Dermatology, Veterans Administration Medical Center, Sepulveda, CA 91343.
Br J Dermatol. 1994 Mar;130(3):298-306. doi: 10.1111/j.1365-2133.1994.tb02924.x.
To determine whether abnormal activity of a calmodulin-containing enzyme which catalyses phosphorylation reactions may play a pathogenetic role in psoriasis, the presence and activity of phosphorylase kinase (PK) in human epidermis were determined in patients with untreated/active psoriasis (n = 10), treated/resolving psoriasis (n = 10), and non-psoriatic controls (n = 10). Biopsies were taken from involved and uninvolved skin for PK, organic phosphorus, and inorganic phosphate estimation, and light and electron microscopy. The enzyme was present in involved and uninvolved skin of every patient in the study. PK activity (units/mg protein) was significantly higher in active psoriasis than in resolving psoriasis and controls. PK activity correlated directly with organic phosphorus levels, and inversely with the extent of cellular glycogenolysis measured by the depletion of glycogen granules within the keratinocytes. The study demonstrates that PK is present in both psoriatic and normal epidermis, with significantly higher levels in active psoriasis. Furthermore, higher levels of PK activity, glycogenolysis and phosphorylation are associated with increased clinical psoriatic activity. We conclude that PK, a calmodulin-containing enzyme, is involved in regulating calcium-dependent phosphorylation events in human epidermis, and disturbance of its activity may play a key role in the clinical manifestations of psoriasis.
为了确定一种催化磷酸化反应的含钙调蛋白的酶的异常活性是否在银屑病发病机制中起作用，我们测定了未经治疗的/活动性银屑病患者（n = 10）、治疗后/病情缓解的银屑病患者（n = 10）和非银屑病对照者（n = 10）的人表皮中磷酸化酶激酶（PK）的存在情况和活性。从受累皮肤和未受累皮肤取材进行PK、有机磷和无机磷酸盐的测定，以及光镜和电镜检查。该酶存在于本研究中每位患者的受累皮肤和未受累皮肤中。活动性银屑病患者的PK活性（单位/毫克蛋白）显著高于病情缓解的银屑病患者和对照者。PK活性与有机磷水平直接相关，与通过角质形成细胞内糖原颗粒消耗测定的细胞糖原分解程度呈负相关。该研究表明，PK存在于银屑病和正常表皮中，在活动性银屑病中水平显著更高。此外，较高水平的PK活性、糖原分解和磷酸化与银屑病临床活动度增加相关。我们得出结论，PK作为一种含钙调蛋白 的酶参与调节人表皮中钙依赖性磷酸化事件，其活性紊乱可能在银屑病的临床表现中起关键作用。
