Effect of estrogen/progesterone ratio on the differentiation and the barrier function of epidermal keratinocyte and three-dimensional cultured human epidermis.

AIMS: Estrogen (E) and progesterone (P) are the major female hormones and are secreted with changing concentration ratios throughout the menstrual cycle. These hormones have been studied individually regarding their physiological function in the skin, but their concentration ratio (E/P) and its effect on the skin has not yet been investigated. The purpose of this study was to clarify the effect of the E/P ratio on skin barrier function. The menstrual cycle was divided into the menstrual, follicular, ovulation, and luteal phases. MATERIALS AND METHODS: The E/P concentration ratios corresponding with each phase were added to a three-dimensional epidermal model or normal human epidermal keratinocytes for 5 days. Gene and protein expression levels of several markers of cell differentiation, including loricrin (LOR) and transglutaminase (TGase), were quantified by real-time PCR and western blotting, respectively. Transepidermal water loss (TEWL) of the three-dimensional epidermal model was measured, and ceramide content was quantified by thin-layer chromatography. KEY FINDINGS: Gene expression of the epidermal differentiation markers, LOR and TGase, increased when applying the concentration ratio of E/P associated with the menstrual and luteal phases. The LOR protein level decreased from menstrual to luteal phases, and the TGase protein level increased from menstrual to luteal phases. During the same phases, ceramide NS increased and TEWL decreased. SIGNIFICANCE: Skin barrier function was improved by culturing cells at specific E/P concentration ratios, which would, therefore, be considered beneficial for female skin. This suggests that dysregulated E/P concentration ratios may be the cause of certain skin problems.

Analysis of human face skin surface molecules in situ by Fourier-transform infrared spectroscopy.

BACKGROUND/PURPOSE: For medical and dermatological researchers, it is important to realize the molecular dynamics and its control in the stratum corneum (SC) of human skin, which may be related to some skin abnormalities such as atopic dermatitis and skin pruritus. We have tried to analyze the periodic molecular dynamics of the outermost layers of SC in vivo. METHODS: We measured the skin surface molecules of human face in situ non-invasively using a Fourier-transform infrared (FTIR) spectroscopy system attached with a newly designed attenuated total reflection (ATR) probe. The water-extracted components from the SC were also analyzed using mass spectrometry, an enzymatic assay and high-performance liquid chromatography characterization. RESULTS: The infrared spectral changes of some components on the face skin at around 1000-1200 cm(-1) with circa-monthly rhythms were observed when monitored for 10 months, and the components also showed a seasonal change. The analysis of different FTIR spectrum of the changeable components with circa-monthly rhythm suggested the presence of a lactate compound. The presence of magnesium lactate in a conjugated form was detected in the water extract of SC. CONCLUSION: We demonstrate that the periodically changed components of the human face skin contained magnesium lactate conjugate as a major component.

Metabolism of fatty acids and lipid hydroperoxides in human body monitoring with Fourier transform Infrared Spectroscopy.

BACKGROUND: The metabolism of dietary fatty acids in human has been measured so far using human blood cells and stable-isotope labeled fatty acids, however, no direct data was available for human peripheral tissues and other major organs. To realize the role of dietary fatty acids in human health and diseases, it would be eager to develop convenient and suitable method to monitor fatty acid metabolism in human. RESULTS: We have developed the measurement system in situ for human lip surface lipids using the Fourier transform infrared spectroscopy (FTIR) - attenuated total reflection (ATR) detection system with special adaptor to monitor metabolic changes of lipids in human body. As human lip surface lipids may not be much affected by skin sebum constituents and may be affected directly by the lipid constituents of diet, we could detect changes of FTIR-ATR spectra, especially at 3005 to approximately 3015 cm(-1), of lip surface polyunsaturated fatty acids in a duration time-dependent manner after intake of the docosahexaenoic acid (DHA)-containing triglyceride diet. The ingested DHA appeared on the lip surface and was detected by FTIR-ATR directly and non-invasively. It was found that the metabolic rates of DHA for male volunteer subjects with age 60s were much lower than those with age 20s. Lipid hydroperoxides were found in lip lipids which were extracted from the lip surface using a mixture of ethanol/ethylpropionate/iso-octane solvents, and were the highest in the content just before noon. The changes of lipid hydroperoxides were detected also in situ with FTIR-ATR at 968 cm(-1). CONCLUSION: The measurements of lip surface lipids with FTIR-ATR technique may advance the investigation of human lipid metabolism in situ non-invasively.