Relationship between skin fungal and bacterial microbiomes and skin pH.

OBJECTIVE: The present study investigated the relationship between the skin bacterial and fungal microbiomes and skin pH at sebaceous sites, namely, the forehead, cheek and upper chest. We also examined the relationship between the skin microbiome and transepidermal water loss (TEWL), which is an indicator of rough skin. METHODS: Thirty healthy Japanese subjects (15 females and 15 males) were enrolled as subjects. The forehead, cheek and upper chest were examined in August (summer) and February (winter). Skin surface samples were collected using the swab method, and the 16s rRNA and ITS regions were analysed using next-generation sequencing. Skin pH and TEWL were also assessed. RESULTS: The changes observed in the skin microbiome were associated with season-dependent changes in skin pH. An increase in skin pH at the forehead and cheek was associated with a higher relative abundance of Cutibacterium spp., a reduction in bacterial diversity, and a lower relative abundance of Staphylococcus spp. A decrease in skin pH at the upper chest was associated with a higher relative abundance of Malassezia restricta, a lower relative abundance of M. sympodialis and decrease in fungal diversity. Moreover, these changes were also associated with an increase in TEWL. CONCLUSION: The present results indicate that changes in skin pH are associated with changes in the skin bacterial and fungal microbiomes at sebaceous sites. The changes observed in the skin microbiome were also associated with rough skin.

OBJECTIF: La présente étude a examiné la relation entre les microbiomes bactériens et fongiques de la peau et le pH de la peau des sites sébacés, à savoir le front, la joue et la partie supérieure du thorax. Nous avons également examiné la relation entre le microbiome cutané et la perte d'eau transépidermique (transepidermal water loss, TEWL), qui est un indice de rugosité cutanée. MÉTHODES: Trente sujets japonais en bonne santé (15 femmes et 15 hommes) ont été inclus en tant que sujets de l'étude. Le front, la joue et la partie supérieure du thorax ont été examinés en août (été) et en février (hiver). Des échantillons de surface cutanée ont été prélevés par écouvillonnage et les régions de l'ARNr 16s et ITS ont été analysées par séquençage à haut débit. Le pH de la peau et la TEWL ont également été évalués. RÉSULTATS: Les changements observés dans le microbiome cutané étaient associés à des modifications du pH de la peau dépendant de la saison. Une augmentation du pH de la peau au niveau du front et de la joue était associée à une plus grande abondance relative de Cutibacterium spp. et à une réduction de la diversité bactérienne, ainsi qu'à une plus faible abondance relative de Staphylococcus spp. Une diminution du pH de la peau au niveau de la partie supérieure du thorax était associée à une abondance relative plus élevée de Malassezia restricta et à une abondance relative plus faible de M. sympodialis, ainsi qu'à une diversité fongique. De plus, ces changements ont également été associés à une augmentation de la TEWL. CONCLUSION: Ces résultats indiquent que les modifications du pH de la peau sont associées à des modifications des microbiomes bactérien et fongique de la peau au niveau des sites sébacés. Les changements observés dans le microbiome de la peau étaient également associés à une rugosité de la peau.

Immunostimulatory effects of a subcritical water extract of Ganoderma.

Ganoderma, a medicinal mushroom with various physiological activities, has been extensively investigated regarding its effectiveness. The aim of the present study was to examine the effects of a subcritical water extract of Ganoderma (SWEG) on the immune system. The use of subcritical water with a higher temperature and pressure than hot water allows efficient elution of components from natural products. As an evaluation of the effectiveness of SWEG, a cell proliferation and a cell differentiation test were carried out using A-6 cells, a model of hematopoietic stem cells. Furthermore, an oral administration test in mice was conducted to examine the effects of SWEG on the number and function of immune cells. As a result, SWEG was revealed to promote both self-renewal and differentiation into immune cells such as T cells and natural killer (NK) cells in experiments with A-6 cells. These results were not obtained in experiments using hot water extract of Ganoderma lucidum and Ganoderma sinense. The oral administration test in mice demonstrated that SWEG increased hematopoietic precursor cells, immature B cells, and NK cells in the bone marrow, and T cells in the thymus. In addition, SWEG enhanced the immune functions in the spleen by promoting granzyme B expression and NK cell activity. SWEG was demonstrated to be a food material that acts on HSCs and regulates immunity in vivo.

The Microbiome in Comedonal Contents of Inflammatory Acne Vulgaris is Composed of an Overgrowth of Cutibacterium Spp. and Other Cutaneous Microorganisms.

Background: Acne vulgaris (acne) and cutaneous resident microorganisms are considered to be closely related. However, the bacterial and fungal microbiota in the comedonal contents of inflammatory acne lesions have not yet been investigated in detail. Purpose: To clarify the relationship between cutaneous microorganisms and acne, we examined the microbiome in the comedonal contents of inflammatory acne and on the facial skin of patients with acne using 16s rRNA and ITS gene sequencing with a next-generation sequencer (NGS). Patients and Methods: Twenty-two untreated Japanese acne outpatients were examined. The comedonal contents of inflammatory acne lesions on the face were collected using a comedo extractor. Skin surface samples from facial skin were collected using the swab method. Results: The results obtained revealed that the predominant bacteria in the comedonal contents of inflammatory acne were Cutibacterium spp. (more prominent in areas with large amounts of sebum), while those on the skin surface were Staphylococcus spp. Malassezia spp., particularly Malassezia restricta, were the predominant fungi in both the comedonal contents of inflammatory acne and on the skin surface. The bacterial microbiome in comedonal contents exhibited stronger metabolic activity, including the production of enzymes related to acne, than that on the skin surface. Conclusion: These results indicate that acne is an inflammatory disease involving the overgrowth of Cutibacterium acnes and other cutaneous resident microorganisms, including Malassezia spp.

Morphological change of skin fibroblasts induced by UV Irradiation is involved in photoaging.

Human dermal fibroblasts (HDFs) are typically flattened or extensible shaped and play a critical role in the metabolism of extracellular matrix components. As the properties of fibroblasts in the dermis are considered to be influenced by their morphology, we investigated the morphological changes induced in fibroblasts by ultraviolet (UV) irradiation as well as the relationship between these changes and collagen metabolism. In this study, we showed that UVA exposure induced morphological changes and reduced collagen contents in HDFs. These morphological changes were accompanied a reduction in actin filaments and upregulation of the actin filament polymerization inhibitor, capping protein muscle Z-line ɑ1 (CAPZA1). External actin filament growth inhibitors also affected the shape of HDFs and reduced collagen levels. These results suggest that UVA exposure may inhibit the polymerization of actin filaments and induce morphological changes in skin fibroblasts. These morphological changes in fibroblasts may accelerate reductions in collagen synthesis. This mechanism may be one of the processes responsible for collagen reductions observed in photoaged skin. When natural materials that suppress these morphological changes in HDFs were evaluated, we found that an extract of Lilium 'Casa Blanca' (LCB) suppressed UVA-induced alterations in the shape of HDFs, which are typically followed by inhibition of collagen reduction. An analysis of the active compounds in LCB extract led to the identification of regaloside I, which had a structure of phenylpropanoid glycerol glucoside, as the active compound inhibiting the upregulation of CAPZA1. Therefore, inhibition of UVA-induced morphological changes in HDFs is considered to be promising way for the suppression of collagen reduction in photoaging.

Inhibitory effect of Phalaenopsis orchid extract on WNT1-induced immature melanocyte precursor differentiation in a novel in vitro solar lentigo model.

Recently, it has been reported that increased expression of WNT1 accelerates the differentiation of melanocyte stem cells (McSCs) in solar lentigines (SLs), hyperpigmented maculae commonly seen on sun-exposed areas of the skin. In this study, to establish an in vitro SL model, human epidermal squamous carcinoma cell line HSC-1, which expresses higher levels of WNT1 than normal human epidermal keratinocytes, was co-cultured with early passage normal human epidermal melanocytes (NHEMs) as an in vitro McSC model. As a result, mRNA expression levels of melanocyte differentiation-related genes MITF and TYR in NHEMs were significantly increased by co-culturing with HSC-1 cells. Furthermore, Phalaenopsis orchid extract (Phex) inhibited McSCs differentiation by suppressing WNT1 expression via down-regulation of DLX2, a transcriptional activator of WNT1, in HSC-1 cells. Therefore, our finding suggested that extracts such as Phex, which suppresses WNT1 expression, may be useful as a novel treatment of SLs.