The effects of oscillatory temperature on HaCaT keratinocyte behaviors

Abstract

BACKGROUND: Keratinocytes are exposed to a thermal gradient throughout epidermal layers in human skin depending on environmental temperatures. OBJECTIVE: Here, the effect of cyclic temperature changes (ΔT) on HaCaT cell behaviors was explored. METHODS: HaCaT cells were cultured at constant temperature (37°C or 25°C) or under ΔT conditions. The morphology, mechanics, cell cycle progression, proliferation, and lipid synthesis of HaCaT cells were determined. RESULTS: ΔT conditions led to the inhomogeneous arrangement of the cytoskeleton in HaCaT cells, which resulted in enlarged size, rounder shape, and increased stiffness. Accumulation in the G2/M phase in the cell cycle, a decreased proliferation rate, and a delayed lipogenesis were detected in HaCaT cells cultured under ΔT conditions. CONCLUSIONS: ΔT conditions resulted in the re-arrangement of the cytoskeleton in HaCaT cells, which showed similarity to the temperature-induced disassemble and re-assemble of cytoskeletons in keratinocyte in vivo. The altered cytoskeleton arrangement resulted in the cell enlargement and stiffening, which reflected the changes in cellular functions. The application of oscillatory temperature in the in vitro culture of keratinocytes provides a way to gain more insights into the role of skin in response to environmental stimuli and maintaining its homeostasis in vivo.