Background And Aims: Psoralen ultraviolet A (PUVA) is an important modality in treating vitiligo. Its effect on melanocytes and keratinocytes is not sufficiently studied. In this work, we investigated 30 cases of non-segmental vitiligo regarding the changes of melanocytes and keratinocytes in both vitiliginous and nearby areas before and after PUVA therapy.
Methods: Three skin biopsies were obtained from each patient from the vitiliginous, marginal and perilesional areas before and after 12 months of PUVA. Biopsies were examined histologically using haematoxylin and eosin, Masson-Fontana stains and 3,4-dihydroxyphenylalanine (DOPA) reaction and histochemically using human melanoma black-45 (HMB-45) antibody while ultrastructural examination was performed on six patients. Control biopsies were taken from five healthy volunteers.
Results: In 10% of pretreated biopsies from the centre of vitiligo lesions, scanty melanocytes were detected histologically and ultrastructurally, while they did not stain with DOPA or HMB-45 antibody suggesting that these melanocytes were inactive. Moreover, degenerative changes were detected by electron microscopy in both melanocytes and keratinocytes in all areas. After PUVA therapy, obvious improvement of the histopathological changes occurred with significant increase in active melanocytes. The degeneration of melanocytes and keratinocytes was also reduced at the ultrastructural level.
Conclusion: Vitiligo affects both melanocytes and keratinocytes causing degenerative changes. These changes were present in both the leucodermic and the apparently normal perilesional skin. PUVA increases the number of active epidermal melanocytes in the three tested areas and recovers the melanocyte and keratinocyte degeneration.
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http://dx.doi.org/10.1111/j.1600-0781.2011.00631.x | DOI Listing |
Inflammation
January 2025
Department of Dermatology, Shunde Hospital, Southern Medical University (The First People's Hospital of Shunde), NO. 1 Jiazi Road, Lunjiao, Shunde District, Foshan City, 528308, Guangdong, China.
The aim of this study was to investigate how ultraviolet B (UVB) light regulates AP-1 expression via the β2-adrenergic receptor (β2-AR) in epidermal keratinocytes, which in turn regulates melanin synthesis in melanocytes, thereby modulating downstream melanin production in skin hair follicles and altering mouse skin color. We established a UV-irradiated mouse model to investigate the effects of UV radiation on changes in skin color. By measuring changes in the expression of genes related to cutaneous sympathetic nerves, norepinephrine synthesis and melanin synthesis, we investigated the relationship between β2-AR expression and cutaneous melanogenesis and determined the localization of β2-AR in cells.
View Article and Find Full Text PDFJ Cosmet Dermatol
January 2025
Department of Dermatology, Hangzhou Third People's Hospital, Zhejiang, Hangzhou, China.
Background: Skin pigmentation disorders may increase patients' psychological burdens. Consequently, they are increasingly attracting attention. Dermal fibroblasts have been shown to regulate pigmentation by secreting soluble factors.
View Article and Find Full Text PDFAntioxidants (Basel)
December 2024
Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
Little is known about the anti-graying effects of antioxidants on hair. The anti-graying effects of three antioxidants (luteolin, hesperetin, and diosmetin) on hair were investigated according to the sequential processes of hair graying that were previously clarified in model mice [Ednrb(+/-);RET-mice]. External treatment with luteolin, but not that with hesperetin or diosmetin, alleviated hair graying in Ednrb(+/-);RET-mice.
View Article and Find Full Text PDFVet Dermatol
January 2025
Department of Veterinary Medicine, University of Perugia, Perugia, Italy.
Background: In humans, the presence of an even distribution of melanocytes within the epidermal basal layer allows for uniform pigmentation in healthy and young individuals. Moreover, despite high variability in skin colours and tones, interindividual melanocyte density variability is low. However, dogs display a high intraindividual pigmentary variability in different anatomical areas.
View Article and Find Full Text PDFGeroscience
December 2024
Institute on the Biology of Aging and Metabolism, University of Minnesota, Twin Cities, Minneapolis, MN, 55455, USA.
Although cellular senescence has been recognized as a hallmark of aging, it is challenging to detect senescence cells (SnCs) due to their high level of heterogeneity at the molecular level. Machine learning (ML) is likely an ideal approach to address this challenge because of its ability to recognize complex patterns that cannot be characterized by one or a few features, from high-dimensional data. To test this, we evaluated the performance of four ML algorithms including support vector machines (SVM), random forest (RF), decision tree (DT), and Soft Independent Modelling of Class Analogy (SIMCA), in distinguishing SnCs from controls based on bulk RNA sequencing data.
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