Extracellular vesicles are transferred from melanocytes to keratinocytes after UVA irradiation.
Ultraviolet (UV) irradiation induces skin pigmentation, which relies on the intercellular crosstalk of melanin between melanocytes to keratinocytes. However, studying the separate effects of UVA and UVB irradiation reveals differences in cellular response. Herein, we show an immediate shedding of extracellular vesicles (EVs) from the plasma membrane when exposing human melanocytes to UVA, but not UVB. The EV-shedding is preceded by UVA-induced plasma membrane damage, which is rapidly repaired by Ca(2+)-dependent lysosomal exocytosis. Using co-cultures of melanocytes and keratinocytes, we show that EVs are preferably endocytosed by keratinocytes. Importantly, EV-formation is prevented by the inhibition of exocytosis and increased lysosomal pH but is not affected by actin and microtubule inhibitors. Melanosome transfer from melanocytes to keratinocytes is equally stimulated by UVA and UVB and depends on a functional cytoskeleton. In conclusion, we show a novel cell response after UVA irradiation, resulting in transfer of lysosome-derived EVs from melanocytes to keratinocytes.
Experimental Pathology, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
Petra
P
Wäster
Experimental Pathology, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
Ida
I
Eriksson
Experimental Pathology, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
Linda
L
Vainikka
Dermatology and Venereology, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
Inger
I
Rosdahl
Experimental Pathology, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
Karin
K
Öllinger
D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism / Q000528:radiation effects; D002478:Cells, Cultured; D002675:Child, Preschool; D018920:Coculture Techniques; D005089:Exocytosis / Q000528:radiation effects; D000067128:Extracellular Vesicles / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007223:Infant; D007231:Infant, Newborn; D015603:Keratinocytes / Q000166:cytology / Q000378:metabolism; D052118:Lysosomal-Associated Membrane Protein 1 / Q000378:metabolism; D008247:Lysosomes / Q000378:metabolism; D008544:Melanocytes / Q000166:cytology / Q000378:metabolism; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D014466:Ultraviolet Rays
D052118:Lysosomal-Associated Membrane Protein 1; D002118:Calcium