Characterization of a Human Skin Equivalent Model to Study the Effects of Ultraviolet B Radiation on Keratinocytes

Abstract

The incidences of skin cancers resulting from chronic ultraviolet radiation (UVR) exposure are on the incline in both Australia and globally. Hence, the cellular and molecular pathways that are associated with UVR-induced photocarcinogenesis need to be urgently elucidated, in order to develop more robust preventative and treatment strategies against skin cancers. In vitro investigations into the effects of UVR (in particular, the highly mutagenic UVB wavelength) have, to date, mainly involved the use of cell culture and animal models. However, these models possess biological disparities to native skin, which, to some extent, have limited their relevance to the in vivo situation. To address this, we characterized a three-dimensional, tissue-engineered human skin equivalent (HSE) model (consisting of primary human keratinocytes cultured on a dermal-derived scaffold) as a representation of a more physiologically relevant platform to study keratinocyte responses to UVB. Significantly, we demonstrate that this model retains several important epidermal properties of native skin. Moreover, UVB irradiation of the HSE constructs was shown to induce key markers of photodamage in the HSE keratinocytes, including the formation of cyclobutane pyrimidine dimers, the activation of apoptotic pathways, the accumulation of p53, and the secretion of inflammatory cytokines. Importantly, we also demonstrate that the UVB-exposed HSE constructs retain the capacity for epidermal repair and regeneration after photodamage. Together, our results demonstrate the potential of this skin equivalent model as a tool to study various aspects of the acute responses of human keratinocytes to UVB radiation damage.

In Vitro Investigations on the Effect of Dermal Fibroblasts on Keratinocyte Responses to Ultraviolet B Radiation

“…Construction of HSE-KC and HSE-KCF skin composites. HSE-KC composites (human keratinocytes cultured on DED scaffolds) were prepared using previously described techniques (22,25). The HSE-KCF (human keratinocytes and fibroblasts on DED scaffolds) were prepared using a protocol modified from HSE-KC construction.…”

In Vitro UVB induced Cellular Damage Assessment Using Primary Human Skin Derived Fibroblasts

“…[1][2][3] The acute effects of UVB are thought to be mediated by cytokine production leading to cell death (early apoptosis). [4][5][6][7] The human skin is composed of a variety of cells including skin fibroblasts. These cells by virtue of their location and numbers in the dermis could be used as possible indicators of cellular damage caused by UVB irradiation.…”

Protective effect of sucupira oil nanoemulsion against oxidative stress in UVA-irradiated HaCaT cells

“…On the other hand, IL‐8 acts as a chemotactic factor that modules positively the inflammatory response mediated by UV radiation in skin . Activation of inflammatory cytokines, including IL‐1, IL‐6, IL‐8, IL‐10, IL‐12 and TNF‐α, triggered by UV radiation, stimulates erythematous and immunomodulatory responses after irradiation . The inhibition of these cytokines can, therefore, prevent the development of skin damage.…”

“…[27] Activation of inflammatory cytokines, including IL-1, IL-6, IL-8, IL-10, IL-12 and TNF-a, triggered by UV radiation, stimulates erythematous and immunomodulatory responses after irradiation. [62] The inhibition of these cytokines can, therefore, prevent the development of skin damage. Downregulation of IL-6 and IL-8 suggests that the NE has also an immunomodulatory activity, which can decrease inflammatory skin response to UVA radiation exposure.…”