Keratinocyte Motility Is Affected by UVA Radiation—A Comparison between Normal and Dysplastic Cells

Abstract

UVA radiation induces multiple and complex changes in the skin, affecting epidermal cell behavior. This study reports the effects of UVA exposure on normal (HaCaT) and dysplastic (DOK) keratinocytes. The adherence, spreading and proliferation were investigated by time-lapse measurement of cell layer impedance on different matrix proteins. Prior to UVA exposure, the time required for adherence and spreading did not differ significantly for HaCaT and DOK cells, while spreading areas were larger for HaCaT cells. Under UVA exposure, HaCaT and DOK cells behavior differed in terms of movement and proliferation. The cells’ ability to cover the denuded surface and individual cell trajectories were recorded by time-lapse videomicroscopy, during wound healing experiments. Dysplastic keratinocytes showed more sensitivity to UVA, exhibiting transient deficiencies in directionality of movement and a delay in re-coating the denuded area. The actin cytoskeleton displayed a cortical organization immediately after irradiation, in both cell lines, similar to mock-irradiated cells. Post-irradiation, DOK cells displayed a better organization of stress fibers, persistent filopodia, and new, stronger focal contacts. In conclusion, after UVA exposure HaCaT and DOK cells showed a different behavior in terms of adherence, spreading, motility, proliferation, and actin cytoskeleton dynamics, with the dyplastic keratinocytes being more sensitive.

Sea-Buckthorn Seed Oil Induces Proliferation of both Normal and Dysplastic Keratinocytes in Basal Conditions and under UVA Irradiation

“…UVA exposure was reported to affect these cell populations differently in terms of migration and proliferation. It was previously demonstrated that dysplastic cells are less able to spread across a denuded area than normal keratinocytes, and were more affected than the latter by UVA treatment [ 17 ]. In terms of cell proliferation, UVA exposure induced cell-cycle arrest for normal keratinocytes [ 20 , 21 ]; this outcome, reviewed in [ 22 ], may lead to an increased doubling time of a cell population, a finding which also was observed in our real-time, impedance-reading experiments.…”

“…Further dilutions were made with complete cell culture medium and appropriate controls containing a comparable dilution of DMSO. Cells were exposed to UVA with a UV-365 nm lamp (VL-340 BLB model—Vilber Lourmat, France) at a light intensity of 381 µW/cm 2 , for 30 min, in a laminar flow hood, as previously described [ 17 ].…”

“…Real-time impedance readings: Cell adhesion and cell proliferation were assessed using RTCA DP platform (Agilent Technologies, Santa Clara, CA, USA). Cells were pre-irradiated with UVA for 30 min as previously described [ 17 ], and then they were trypsinized and seeded in E-16 plates at a density of 20,000 cells/well, with or without the cell medium, and supplemented or not with sea-buckthorn oil 1/8000. Readings were collected every 5 min for 24 h. Cell index at 2 h (at plateau) was used for statistical analysis (One-Way Anova, Dunnett multiple comparison, where data were compared to control.…”

Noninvasive measurement of cell/colony motion using image analysis methods to evaluate the proliferative capacity of oral keratinocytes as a tool for quality control in regenerative medicine

“…In addition, the molecular mechanisms of cell motion and cellular proliferative capacity need to be investigated. 41–43…”

State of the Art on Biomaterials for Soft Tissue Augmentation in the Oral Cavity. Part I: Natural Polymers-Based Biomaterials

“… Typical round-shaped images of the keratinocytes cytoskeleton (arrows) obtained by immunofluorescence, from Niculiţe et al [ 26 ]. Copyright MDPI, 2018 ( a ).…”