MicroRNAs in cutaneous lichen planus.

Lichen planus (LP) is a chronic, inflammatory, papulosquamous, autoimmune disease. The pathogenesis of LP appears to be complex, with interactions between genetic, environmental and lifestyle factors. MicroRNAs (miRNAs) are short RNAs encoded in both protein coding and noncoding areas of the genome, and have been found to be involved in the pathogenesis of some inflammatory skin diseases. The aim of this study was to map the levels of miRNA (miR-)-203 and miR-125b in cutaneous LP to evaluate their possible role in the pathogenesis of the disease. In total, 40 patients with classic cutaneous LP and 40 age- and sex- matched healthy controls (HCs) were enrolled in this study. Punch biopsies (4 mm) were taken from cutaneous LP lesions of patients and from normal skin of HCs. miRNA-203 and miRNA-125b mRNA expression was estimated by reverse transcription PCR. Our analysis revealed a significantly (P < 0.001 for both) lower expression of both miR-203 and miR-125b mRNA in the LP than in the HC biopsies. No relationship was found between expression of miR-203 or miR-125b and either age, sex, presence of mucosal lesions or positivity for HCV antibodies. miR-125b and miR-203 could be involved in the pathogenesis of cutaneous LP.

The trichotillometry: a technique for hair assessment.

BACKGROUND: There are many different non-invasive or invasive techniques for studying the hair state either in the normal or diseased conditions. OBJECTIVE: A technique is used to evaluate the current hair status through setting a normal standard value or range of the epilating force of different hair follicle types in normal individuals. METHODS: The trichotillometer is used to record in grams the force exerted to epilate a single hair in different locations of scalp. RESULTS: Of all the plucked hairs from all the volunteers, the epilating force, the diameter, and the follicular length were calculated. The shear strain needed for epilating different hair types is calculated. CONCLUSION: Using the trichotillometry technique to identify the normal range of the shear strain for different hair types is important as it may aid in diagnostic, prognostic, or even therapeutic decision making for many hair diseases.

The role of cyclooxygenase-2 and prostaglandin E2 in the pathogenesis of cutaneous lichen planus.

BACKGROUND: 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. AIM: To map levels of COX-2 and PGE2 in cutaneous LP lesions and evaluate their role in the pathogenesis of the disease. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.