leukotriene-c4 and Vitiligo

The aim of this study is to investigate the effect of the non-steroidal anti-inflammatory agent, acetylsalicylic acid (ASA), otherwise known as aspirin, at different concentrations on the release rates of the pro-inflammatory mediators, leukotriene B4 (LTB4) and leukotriene C4 (LTC4) from in vitro cultured melanocytes obtained from normal pigmented skin of patients with active vitiligo.. This study was carried out between April, 2000 and September, 2001, at The Vitiligo Unit, King Abdul-Aziz University Medical Center, Jeddah, Kingdom of Saudi Arabia. Skin biopsies were obtained from patients with active vitiligo (n=7) of different extent and duration, and normal healthy age-matched individuals (n=7) serving as control were recruited to the study. The release rates of LTB4 and LTC4 were determined before and after the addition of the ASA at 3 different concentrations (15, 75, 150 microg/ml) in the primary skin melanocytes culture medium using a commercially available kit based on radioimmunoassay method.. Following the ASA treatment at 3 different concentrations (15, 75 and 150 microg/ml), the release rates of LTB4 and LTC4 were increased from melanocytes of the normal individuals (13%, 7.5% and 30%; 7.2%, 51.4% and 60.7%, p<0.001). However, in patients with active vitiligo, the release rate of LTB4 from melanocytes was decreased (2.9%, 14.4% and 7.4%, p<0.05), whereas that of LTC4 was increased (3.9%, 93.8% and 101.4%, p<0.001).. Acetylsalicylic acid at therapeutic concentrations can regulate the release rates of LTB4 and LTC4 from cultured skin melanocytes of normal and active vitiligo subjects.

Topics: Adolescent; Adult; Analysis of Variance; Anti-Inflammatory Agents, Non-Steroidal; Aspirin; Case-Control Studies; Cells, Cultured; Dose-Response Relationship, Drug; Female; Humans; Inflammation Mediators; Leukotriene B4; Leukotriene C4; Male; Melanocytes; Middle Aged; Probability; Reference Values; Sensitivity and Specificity; Vitiligo

An ex vivo model system was developed to investigate melanocyte migration. Within this model system, melanocytes migrate among other epidermal cells in the epibolic outgrowth of skin explants. This process is initiated by loss of contact inhibition of epidermal cells at the rim of the explants and by locally produced chemotactic factors. Punch biopsies provided explants of reproducible diameter. Optimal culture conditions include medium consisting of Dulbecco's Minimal Essential Medium containing 10% inactivated normal human serum and placement of explants epidermal side up at the air-liquid interphase. Within 7 days, epidermal cells completely surround the explant. Approximately 3 days after the onset of keratinocyte migration, melanocytes distribute themselves within the newly formed epidermis. Throughout the 7-day culture period, melanocytes and keratinocytes show maintenance of subcellular morphology, and the dermo-epidermal junction remains intact. Melanocyte migration was quantified using immunoperoxidase staining in combination with light microscopy and computer-aided image analysis. Preliminary results using the model system to compare migration in control and nonlesional vitiligo skin indicate that no inherent migration defect is responsible for impaired repigmentation of vitiligo lesions. The organotypic culture model system allows for investigations on melanocytes within their environment of autologous epidermal and dermal components, closely resembling in vivo circumstances in human skin.

Topics: Adult; Biopsy; Cell Division; Cell Movement; Contact Inhibition; Epidermal Cells; Humans; Infant, Newborn; Keratinocytes; Leukotriene C4; Melanocytes; Microscopy, Electron; Organ Culture Techniques; Skin; Vitiligo