Up-regulation of tight junction-related proteins and increase of human epidermal keratinocytes barrier function by Saccharomycosis ferment filtrate

Jong-Hwei Pang,Tzu-Ya Chen,Wen-Rou Wong,Takashi Yoshii,Tomohiro Hakozaki

doi:10.4236/jcdsa.2011.11003

Jong-Hwei Pang, Tzu-Ya Chen + Show 3 more

Open Access

https://doi.org/10.4236/jcdsa.2011.11003

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Abstract

Saccharomycopsis ferment filtrate (SFF), mainly used in skin care products, has been reported to inhibit inflammatory nitric oxide production and prevent epidermal damage. However, the effects of SFF on epidermal keratinocytes have not yet been explored. We investigated the effects of SFF on skin barrier function using human primary epidermal keratinocytes. Cell viability was determined by MTT assay. The mRNA and protein expression levels of tight junction proteins (claudin-1, -3, -4, occludin, ZO-1) were analyzed by RT-PCR and Western blotting, respectively. The effect of SFF on the barrier formation of epidermal keratinocytes was measured by transepithelial electrical resistance (TER). Rescue of cell death from H2O2 treatment was evaluated by annexin V staining. SFF, at concentrations that did not cause significant change of cell viability, induced dose-dependent cell-cell adhesion and formation of an organized monolayer structure. Pretreatment of keratinocytes with EGTA, a Ca2+ chelator, did not inhibit the cell-cell adhesion of keratinocytes by SFF, indicating a Ca2+-independent mechanism. The mRNA and protein levels of claudin-1 in keratinocytes were up-regulated by SFF treatment in a dose-dependent manner. The expressions of other tight junctions (TJs) including claudin-3 & 4, occludin and ZO-1 were also similarly increased in SFF-treated epidermal keratinocytes. The promoting effect of SFF on the barrier function of epidermal keratinocytes was further confirmed by the increased TER value in SFF-treated epidermal keratinocytes. Annexin V staining confirmed that SFF markedly decreased the number of dead cells resulted from H2O2 injury. Taken together, our results provided the first evidence that SFF enhanced keratinocytes barrier function by increasing the expression of TJs and TER.

Highlights

The epidermis of the skin is the outermost layer of the human body and is in direct contact with the outside world
After the addition of Saccharomycopsis ferment filtrate (SFF), epidermal keratinocytes began to adhere to nearby cells and form an organized sheet-like structure
This cell-cell adhesion of epidermal keratinocytes induced by SFF was observed at the concentration of 0.5 × SFF and better organization of the sheet-like structure was observed at the concentration of 1 × SFF (Figure 1B)

Summary

Introduction

The epidermis of the skin is the outermost layer of the human body and is in direct contact with the outside world. Epidermal cells bound tightly together provide a physical barrier against injurious chemicals or pathogens from the outside, while simultaneously, preventing water or nutritional loss from the inside of our body The basis of these effects lies in the well-defined differentiation program of keratinocytes which results in the expression of structure proteins and in turn, function as a protective barrier. Since the study of TJs in skin epidermis is relatively delayed, the presence of TJs, another potential barrier component in human epidermis had been mostly disregarded until the analysis of claudin-1 deficient mice [3] These claudin-1 deficient mice usually died within 1 day of birth due to defected epidermal barrier function thereby causing excessive transepidermal water loss (TEWL) and severe dehydration [3]

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