A new model to investigate UVB-induced cellular senescence and pigmentation in melanocytes. (September 2020)

• Record Type: Journal Article
• Authors: Martic, Ines; Wedel, Sophia; Jansen-Dürr, Pidder; Cavinato, Maria
• Is Part Of: Mechanisms of ageing and development. Volume 190(2020)
• Publication Date: 2020-09
• Subjects: Atg7 Autophagy-related protein 7 -- cPDLs cumulative population doublings -- DAPI 4′6-diamidino-2-phenylindole -- D1 Day one -- D3 Day three -- D4 Day four -- D7 Day seven -- D9 Day nine -- D15 Day fifteen -- DMEM Dulbecco´s modified eagle´s medium -- DMSO Dimethylsulfoxide -- EDTA Ethylenediaminetetraacetic acid -- FACS Fluorescence-activated cell sorting -- FCS Fetal calf serum -- FM Fontana-Masson -- GAPDH Glyceraldehyde 3-phosphate dehydrogenase -- GFP-degron degron-destabilized green fluorescent protein -- HEK293-T Human embryonic kidney 293 cells containing the SV40 T-antigen -- HDFs Human dermal fibroblasts -- HSEM Human skin epidermal melanocytes -- LC3 Microtubule-associated protein light chain 3 -- LLnL N-acetyl-L-leucyl-L-leucyl-leucyl-L-norleucinal -- MMPs Matrix metalloproteases -- NaOH Sodium hydroxide -- PBS Phosphate buffered saline -- PFA Paraformaldehyde -- pp53 Phosphorylation of p53 on serine 15 -- RIPA Radioimmunoprecipitation assay buffer -- ROS Reactive oxygen species -- RT Room temperature -- SASP Senescence-associated secretory phenotype -- SA-β-Gal Senescence-associated β-Galactosidase -- SD Standard deviation -- U2OS Human osteosarcoma cell line -- UV Ultraviolet; Senescence -- Skin aging -- Melanogenesis -- Pigmentation -- Proteostasis; Aging -- Periodicals; Developmental biology -- Periodicals; Aging -- Periodicals; Developmental Biology -- Periodicals; Vieillissement -- Périodiques; Biologie du développement -- Périodiques; Aging; Developmental biology; Periodicals; 612.67
• DOI: 10.1016/j.mad.2020.111322
• Languages: English
• ISSNs: 0047-6374

Abstract

Highlights: Mild and repeated doses of UVB induce senescence of human epidermal melanocytes. UVB-irradiated melanocytes show impaired proteasome activity and increased autophagy. UVB irradiation induces melanogenesis in melanocytes. Photoaged fibroblasts secrete factors that boost melanogenesis of melanocytes. Abstract: Ultraviolet (UV) light is known to potentially damage human skin and accelerate the skin aging process. Upon UVB exposure, melanocytes execute skin protection by increasing melanin production. Senescent cells, including senescent melanocytes, are known to accumulate in aged skin and contribute to the age-associated decline of tissue function. However, melanocyte senescence is still insufficiently explored. Here we describe a new model to investigate mechanisms of UVB-induced senescence in melanocytes and its role in photoaging. Exposure to mild and repeated doses of UVB directly influenced melanocyte proliferation, morphology and ploidy. We confirmed UVB-induced senescence with increased senescence-associated β-galactosidase positivity and changed expression of several senescence markers, including p21, p53 and Lamin B1. UVB irradiation impaired proteasome and increased autophagic activity in melanocytes, while expanding intracellular melanin content. In addition, using a co-culture system, we could confirm that senescence-associated secretory phenotype components secreted by senescent fibroblasts modulated melanogenesis. In conclusion, our new model serves as an important tool to explore UVB-induced melanocyte senescence and its involvement in photoaging and skin pigmentation.