Functional validation of co‐culture model of human keratinocytes and neuronal cell line for sensitive skin by using transient receptor potential channel vanilloid subfamily member 1 antagonist

Abstract

Background Sensitive skin is a subjective cutaneous hyper‐reactivity that occurs in response to various innocuous stimuli. Keratinocytes have recently been shown to participate in sensory transduction by releasing many neuroactive molecules that bind to intra‐epidermal free nerve endings and modulate nociception. In the literature, the characterization of these interactions has been based on the co‐culture of keratinocyte and mammalian‐origin neuronal cell lines. In this study, we established an in vitro model based on a co‐culture of primary human keratinocytes and differentiated SH‐SY5Y cells, a human neuronal cell line. Methods Human epidermal keratinocytes and SH‐SY5Y cells were monocultured and co‐cultured. Changes in calcium influx, substance P, inflammatory cytokines, and neuropeptides between the monoculture and co‐culture groups treated with capsaicin only and capsaicin with transient receptor potential channel vanilloid subfamily member 1 (TRPV1) antagonist, trans‐4‐tert‐butylcyclohexanol (TTBC), together. In addition, the difference in stinging sensation was evaluated by applying it to the volunteers. Results When SH‐SY5Y cells were co‐cultured with keratinocytes, they had no significant effect on axonal development. Substance P was also released after capsaicin treatment and reduced by TTBC under co‐culture conditions. Moreover, the expression of inflammatory cytokines and neuropeptides was significantly increased in co‐cultured keratinocytes compared to that under monoculture conditions. In addition, the stinging sensation was significantly induced after the application of capsaicin in vivo and was relieved after the application of the TRPV1 antagonist. Conclusion We demonstrated that the novel co‐culture model is functionally valid through capsaicin and TRPV1 antagonist. We also confirmed that TTBC could be used for the treatment of sensitive skin through a co‐culture model and in vivo tests. This co‐culture model of keratinocytes and SH‐SY5Y cells may be useful in vitro alternatives for studying the close communication between keratinocytes and neuronal cells and for screening therapeutic drugs for sensitive skin.

Polydeoxyribonucleotide exerts opposing effects on ERK activity in human skin keratinocytes and fibroblasts

“…HALLYM 2019-07-029; Republic of Korea). Human epidermal keratinocytes (HEKs) were isolated from foreskins of patients through circumcisions ( 20 ). Epidermal layers were separated from dermis via enzymatic digestion.…”

Metabolic Priming as a Tool in Redox and Mitochondrial Theragnostics

“…In order to improve translational research (Figure 2), several actions should be taken into account during theragnostic studies: (a) selecting an appropriate cellular model that reflects the disease or condition being studied is crucial [164]; (b) preconditioning cells by adjusting cell culture conditions, and manipulating cellular metabolism through changes in pH, O2 levels, and nutrient availability is essential to simulate the original cellular environment as closely as possible [165][166][167][168]; (c) introducing cell genetic modifications to enhance their suitability for theragnostic applications [169,170]; (d) validating the cellular model is crucial to ensure its appropriateness for a specific purpose or context of use [171]. This validation process may include analyses based on morphology (shape, size, and organization of the cells, using machine learning techniques could be helpful [172]), function (e.g., response of cells to specific stimuli [165,167,168,171,173]), and genotype (expression of specific genes or the existence of genetic mutations [165,174]). Metabolic priming strategies applied to a wide range of pathologies can be achieved through hypoxia, nutrient deprivation, or metabolite supplementation, which will be discussed further in the following subsections.…”