<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Ultraviolet B (UVB) induces morphological and functional changes of the skin. This study investigated the effect of UVB on keratinocyte senescence and the development of reconstructed human epidermis (RHE). Primary normal human keratinocytes (NHK) from juvenile foreskin were irradiated with UVB (30 mJ cm<sup>−2</sup>) and these effects were compared to NHK that underwent senescence in the late passage. UVB enhanced the accumulation of reactive oxygen species (ROS) and halted cell replication as detected by BrdU cell proliferation assay. The senescence phenotype was evaluated by beta-galactosidase (β-gal) staining and qPCR of genes related to senescent regulation, <italic>i.e.</italic> p16INK4a, cyclin D2, and IFI27. Senescence induced by high dose UVB resulted in morphological changes, enhanced β-gal activity, elevated cellular ROS levels and reduced DNA synthesis. qPCR revealed differential expression of the genes regulated senescence. p16INK4a expression was significantly increased in NHK exposed to UVB whereas enhanced IFI27 expression was observed only in cultural senescence. The levels of cyclin D2 expression were not significantly altered either by UVB or long culturing conditions. UVB significantly induced the aging phenotype in keratinocytes and impaired epidermal development. RHE generated from UVB-irradiated keratinocytes showed a thinner cross-sectional structure and the majority of keratinocytes in the lower epidermis were degenerated. The 3D epidermis model is useful in studying the skin aging process.</p></abstract>

Ultraviolet B (UVB) induces morphological and functional changes of the skin. This study investigated the effect of UVB on keratinocyte senescence and the development of reconstructed human epidermis (RHE). Primary normal human keratinocytes (NHK) from juvenile foreskin were irradiated with UVB (30 mJ cm−2) and these effects were compared to NHK that underwent senescence in the late passage. UVB enhanced the accumulation of reactive oxygen species (ROS) and halted cell replication as detected by BrdU cell proliferation assay. The senescence phenotype was evaluated by beta-galactosidase (β-gal) staining and qPCR of genes related to senescent regulation, i.e. p16INK4a, cyclin D2, and IFI27. Senescence induced by high dose UVB resulted in morphological changes, enhanced β-gal activity, elevated cellular ROS levels and reduced DNA synthesis. qPCR revealed differential expression of the genes regulated senescence. p16INK4a expression was significantly increased in NHK exposed to UVB whereas enhanced IFI27 expression was observed only in cultural senescence. The levels of cyclin D2 expression were not significantly altered either by UVB or long culturing conditions. UVB significantly induced the aging phenotype in keratinocytes and impaired epidermal development. RHE generated from UVB-irradiated keratinocytes showed a thinner cross-sectional structure and the majority of keratinocytes in the lower epidermis were degenerated. The 3D epidermis model is useful in studying the skin aging process.

Ultraviolet B irradiation-induced keratinocyte senescence and impaired development of 3D epidermal reconstruct

Department of Pharmacology Faculty of Medicine

Department of Preclinical Sciences Faculty of Medicine

Acta Pharmaceutica

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Ultraviolet B (UVB) induces morphological and functional changes of the skin. This study investigated the effect of UVB on keratinocyte senescence and the...

Ultraviolet B irradiation-induced keratinocyte senescence and impaired development of 3D epidermal reconstruct

Published Online: Nov 04, 2020

Page range: 293 - 303

Accepted: Apr 13, 2020

DOI: https://doi.org/10.2478/acph-2021-0011

Keywords
epidermis, keratinocytes, ultraviolet radiation, skin aging, senescence, reactive oxygen species

© 2021 Suvara K. Wattanapitayakul et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Ultraviolet B irradiation-induced keratinocyte senescence and impaired development of 3D epidermal reconstruct

Published Online: Nov 04, 2020

Page range: 293 - 303

Accepted: Apr 13, 2020

DOI: https://doi.org/10.2478/acph-2021-0011

Keywordsepidermis, keratinocytes, ultraviolet radiation, skin aging, senescence, reactive oxygen species

© 2021 Suvara K. Wattanapitayakul et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Keywords
epidermis, keratinocytes, ultraviolet radiation, skin aging, senescence, reactive oxygen species