Gap junction and atopic dermatitis: a study of connexin 43 mRNA expression in atopic skin lesions

Background Atopic dermatitis is a highly pruritic, chronic inflammatory skin disease. There is no doubt that there is an epidermal barrier defect in atopic dermatitis. Some recent studies have found a correlation between epidermal barrier function and tight junction. Recently a correlation between tight and gap junction was also reported. Objective To study the expression of connexin 43(Cx43) mRNA, an important constituent of gap junction in the skin in atopic dermatitis lesions and to compare it with healthy controls. Patients and methods The study was carried out in 20 patients with atopic dermatitis. Fifteen healthy volunteers served as controls. A 4-mm punch skin biopsy specimen was obtained from each patient and control for quantitative reverse transcription-PCR measurement of Cx43 mRNA expression. Biopsy specimens were stored at –708C. Reverse transcription-PCR was conducted using the extracted RNA for the detection of the Cx43 gene. Results The mean Cx43 mRNA expression in the patients was 1.23± 0.1 mg/gm tissue and 0.27±0.05 mg/gm in the control group. This denoted a significant statistical difference between the groups (P value =0.000) revealing higher expression in patients with atopic dermatitis. Conclusion This study suggests a new hypothesis for atopic dermatitis pathogenesis showing a possible contribution of gap junction abnormality in the disease. These findings raise new future directions for management of patients with atopic dermatitis.