El-Rifaie A A, Rashed L A, Doss R W
Dermatology Department, Faculty of Medicine, Beni Suef University, Beni Suef, Egypt.
Biochemistry Department, Faculty of Medicine, Cairo University, Cairo, Egypt.
Clin Exp Dermatol. 2015 Dec;40(8):903-7. doi: 10.1111/ced.12663. Epub 2015 May 17.
Lichen planus (LP) is an inflammatory disease of the skin and mucous membranes. Autoimmunity has been suggested as a possible cause of this disease. The cyclooxygenase enzymes (COX-1, COX-2) are the key enzymes in the conversion of arachidonic acid into prostaglandins. Prostaglandin E2 (PGE2), a key product of COX-2, has an immunomodulatory role.
To map levels of COX-2 and PGE2 in cutaneous LP lesions and evaluate their role in the pathogenesis of the disease.
In total, 31 patients with classic cutaneous LP and 30 age- and sex-matched healthy controls were enrolled. Skin biopsies were taken from the lesional and nonlesional skin of patients, and from the normal skin of controls. COX-2 mRNA expression was detected by real-time reverse transcription quantitative PCR, and PGE2 was detected by ELISA in skin biopsies from patients and controls.
Our analysis revealed a significantly higher expression of COX-2 mRNA and PGE2 in the LP skin biopsies compared with the control biopsies (P < 0.001 and P < 0.001, respectively). Lesional biopsies showed significantly higher expression of COX-2 mRNA and PGE2 compared with nonlesional biopsies. The levels of COX-2 and PGE2 were not found to be correlated with age, sex or disease duration.
COX-2 and its product PGE2 are strongly expressed in LP skin lesions, indicating that they have a role in the pathogenesis of LP through their immunomodulatory effects.
扁平苔藓（LP）是一种皮肤和黏膜的炎症性疾病。自身免疫被认为是该疾病可能的病因之一。环氧化酶（COX-1、COX-2）是花生四烯酸转化为前列腺素的关键酶。前列腺素E2（PGE2）是COX-2的关键产物，具有免疫调节作用。
测定皮肤扁平苔藓病变中COX-2和PGE2的水平，并评估它们在该疾病发病机制中的作用。
共纳入31例经典皮肤扁平苔藓患者和30例年龄及性别匹配的健康对照。从患者的皮损和非皮损皮肤以及对照的正常皮肤取皮肤活检组织。通过实时逆转录定量PCR检测COX-2 mRNA表达，通过ELISA检测患者和对照皮肤活检组织中的PGE2。
我们的分析显示，与对照活检组织相比，扁平苔藓皮肤活检组织中COX-2 mRNA和PGE2的表达显著更高（分别为P < 0.001和P < 0.001）。与非皮损活检组织相比，皮损活检组织中COX-2 mRNA和PGE2的表达显著更高。未发现COX-2和PGE2的水平与年龄、性别或病程相关。
COX-2及其产物PGE2在扁平苔藓皮肤病变中强烈表达，表明它们通过免疫调节作用在扁平苔藓的发病机制中发挥作用。
