Expression of cannabinoid receptor type 2 in skin lesions of psoriasis vulgaris

Abstract

Objective To investigate the expression of cannabinoid receptor type 2 (CNR2) in skin lesions of psoriasis vulgaris, and to explore its significance. Methods Tissue samples were obtained from lesions and perilesional skin of 20 patients with psoriasis vulgaris, and normal skin of 10 human controls without psoriasis or other autoimmune dermatoses. Real-time fluorescence-based quantitative PCR and immunohistochemistry were performed to determine the mRNA and protein expression levels of CNR2 in these samples. Statistical analysis was carried out by using two-sample t test and chi-square test. Results CNR2 mRNA and protein were expressed in the normal control skin, lesional skin and perilesional skin tissues. As immunohistochemistry showed, CNR2 was distributed diffusedly in the prickle cell layer in lesional skin, but expressed in the basal cell layer of the epidermis in normal control skin and perilesional skin. The mRNA expression level (2-△△Ct) of CNR2 was significantly higher in lesional skin than in normal control skin and perilesional skin tissues (3.97 vs. 1.00 and 1.49, both P 0.05). The expression rate of CNR2 protein was significantly higher in lesional skin (90%(18/20) than in perilesional skin (15% (3/20), χ2=22.56, P< 0.01) and normal control skin tissues (10% (2/20), χ2=18.37, P < 0.01), while there was no significant difference between normal control skin and perilesional skin tissues (χ2=0.14, P=0.70). Conclusions The mRNA and protein expressions of CNR2 are both increased in skin lesions of psoriasis vulgaris, suggesting that CNR2 may be related to the occurrence and development of psoriasis vulgaris. Key words: Psoriasis; Genes; Receptors, cannabinoid, 2