Background Vitiligo is an acquired pigmentary disorder characterized by depigmented patches on the skin that majorly impact patients' quality of life. Although its etiology involves genetic and environmental factors, the role of microorganisms as environmental factors in vitiligo pathology remains under-researched. Objectives Our study explored the presence of characteristic bacterial and fungal flora in vitiligo-affected skin and investigated their potential roles in vitiligo pathogenesis. Methods We sequenced bacterial 16 S rRNA and the fungal ITS1 region from skin swabs collected at frequently affected sites, namely the forehead and back, of patients with vitiligo. We analyzed bacterial and fungal flora in lesional and non-lesional areas of patients with vitiligo compared with corresponding sites in age- and sex-matched healthy subjects. Results Our findings revealed elevated α-diversity in both bacterial and fungal flora within vitiligo lesions compared with healthy controls. Notably, bacterial flora exhibited a distinctive composition in patients with vitiligo, and the proportional representation of Enterococcus was inversely correlated with the degree of vitiligo progression. Gammaproteobacteria, Staphylococcus spp., and Corynebacterium spp. were more abundant in vitiligo patients, with notable Staphylococcus spp. prevalence during the stable phase on the forehead. Conversely, the proportion of Malassezia sympodialis was lower and that of Malassezia globosa was higher in the progressive phase on the back of vitiligo patients. Conclusion Our study identified some characteristic bacterial and fungal groups associated with vitiligo activity and prognosis, highlighting the potential roles of microorganisms in pathogenesis and offering insights into personalized disease-management approaches.
Abstract Objectives Hyaluronan ( HA ), an important constituent of extracellular matrix in the skin, has many biological activities such as hydration that contributes to firmness and bounciness of the skin. We have reported that reduction in HA in the papillary dermis and over‐expression of HYBID ( HY aluronan Binding protein Involved in hyaluronan Depolymerization, alias KIAA 1199 or CEMIP ), a key molecule for HA degradation in skin fibroblasts, are implicated in facial skin wrinkling in Japanese and Caucasian women. However, little or no information is available for substances which inhibit the HYBID ‐mediated HA degradation. Methods Inhibition of Sanguisorba officinalis root extract and ziyuglycoside I, one of the components of Sanguisorba officinalis root extract, to the HYBID ‐mediated HA degradation was assessed by size‐exclusion chromatography of HA depolymerized by stable transfectants of HYBID in HEK 293 cells ( HYBID / HEK 293 cells) or normal human skin fibroblasts (Detroit 551 cells and NHDF ‐Ad cells). The HYBID mRNA and protein expression was examined by quantitative real‐time PCR and immunoblotting in the skin fibroblasts treated with Sanguisorba officinalis root extract, and size distribution of newly produced HA was evaluated by preparing metabolically radiolabelled HA . A double‐blind, randomized and placebo‐controlled study was carried out in the 21 healthy Japanese women, who were topically treated with the formulation containing Sanguisorba officinalis root extract or the placebo on each side of the face including crow's foot area. Results Sanguisorba officinalis root extract, but not ziyuglycoside I, abolished HYBID ‐mediated HA degradation by HYBID / HEK 293 cells. Sanguisorba officinalis root extract also inhibited HYBID ‐mediated HA degradation in skin fibroblasts by down‐regulating HYBID mRNA and protein expression. Although control untreated skin fibroblasts produced polydispersed HA , the cells treated with Sanguisorba officinalis root extract produced only high‐molecular‐weight HA . Treatment with Sanguisorba officinalis root extract‐formulated lotion significantly improved skin elasticity, and reduced skin wrinkling scores at the outer eye corner compared with the placebo formulation. Conclusion Sanguisorba officinalis root extract showed an anti‐ HYBID ‐mediated HA degradation activity and anti‐wrinkle activity on human facial skin, which is accompanied by the improvement in elasticity. Our study provides the possibility of a new strategy to inhibit HYBID ‐mediated HA degradation for anti‐wrinkle care.
We examined the effects of <i>N</i>-methyl-L-serine (NMS), an amino acid derivative, on hyaluronan (HA) synthesis in human skin fibroblasts. NMS (1–10 m<i>M</i>), but not L-serine, stimulated the incorporation of [<sup>3</sup>H]glucosamine into HA dose-dependently, with a maximum stimulation of 1.5-fold compared to the control. The effect of NMS was specific for HA production, because there was no change in sulfated glycosaminoglycan formation. Neither the <i>N</i>-methyl derivatives of L-glycine or L-alanine, nor <i>N</i>-methyl-D-serine, could stimulate HA synthesis, indicating that the β-hydroxyl group and the L-configuration were essential for the activity. Gel filtration of the products showed that NMS stimulated the production of high-molecular-mass HA (>10<sup>6</sup> D) without affecting the production of low-molecular-mass HA. NMS required 24 h to stimulate HA production, and when fibroblasts were pretreated for 10–24 h with NMS (1–10 m<i>M</i>), membrane-associated HA synthase activity was increased dose-dependently. Thus, a second messenger is likely to be involved in the stimulation of HA production by NMS.
Hyaluronan (HA) metabolism in skin fibroblasts is mediated by HYBID (hyaluronan binding protein involved in hyaluronan depolymerization, alias CEMIP and KIAA1199) and the HA synthases HAS1 and HAS2. However, photoageing‐dependent changes in HA and their molecular mechanisms, and the relationship between HA metabolism and clinical symptoms in photoaged skin remain elusive. We examined the amount, size and tissue distribution of HA and expression levels of HYBID, HAS1 and HAS2 in photoaged skin, and analysed their relationship with the degree of photoageing. Photoageing‐dependent changes of HA were investigated by studying skin biopsies isolated from photoprotected and photoexposed areas of the same donors, and the relationships between HA and photoageing symptoms such as skin wrinkling and sagging were examined. Skin biopsy specimens showed that the amount and size of HA are decreased in photoexposed skin compared with photoprotected skin, and this was accompanied by increased expression of HYBID and decreased expression of HAS1 and HAS2. Histologically, HA staining in the papillary dermis was decreased in photoexposed skin, showing reverse correlation with HYBID expression. HYBID expression in the photoexposed skin directly correlated with skin roughness and sagging parameters, and the reduced HA staining in the papillary dermis in the photoexposed skin positively correlated with these symptoms. These data demonstrate that imbalance between HYBID‐mediated HA degradation and HAS‐mediated HA synthesis may contribute to enhanced HA catabolism in photoaged skin, and suggest that HYBID‐mediated HA reduction in the papillary dermis is related to skin wrinkling and sagging of photoaged skin.
We examined the relationship between depth-resolved local optical properties of eye-corner skin measured by multifunctional Jones matrix optical coherence tomography (JM-OCT) and corresponding wrinkle morphology of aged women (n=21; age range, 71.7±1.7). Wrinkle morphology parameters were analyzed by measuring surface topography of three-dimensional silicone replicas. The same regions were measured three-dimensionally by JM-OCT and the means of several optical properties were computed at each depth. Optical properties include birefringence (BR), attenuation coefficient (AC), and degree-of-polarization uniformity (DOPU). BR and AC were correlated with mean wrinkle depth (WD), although DOPU was not. Significant correlations were found between WD and BR at 88.2 to 138.6 μm depth region from the skin surface (highest correlation at 113.4 μm), and between WD and AC at 12.6 to 18.9 μm and 189 to 459.9 μm depth regions from the skin surface (highest correlations at 18.9 μm and 415.8 μm). This suggests that the collagen structure of the papillary dermis and the microstructure and/or tissue density of the upper epidermis and reticular dermis may be associated with wrinkle morphology. Multiple regression analysis was used to examine the highest significant correlations of BR (113.4 μm) and AC (18.9 μm, 415.8 μm). A significant regression coefficient (R2=0.547, p = 0.001) was obtained, indicating that only BR and AC could sufficiently explain WD. Beta coefficients of BR (113.4 μm), AC (18.9 μm), and AC (415.8 μm) were −0.384, −0.369, and −0.354, respectively. This suggests that the upper epidermis, papillary dermis, and reticular dermis may contribute similarly to wrinkle formation.
Carotenoids have been reported to have potent antioxidant activities and to protect tissues and cells from certain diseases and environmental insults. The molecular mechanism of the action of provitamin A carotenoids such as β-carotene and β-cryptoxanthin is mediated in part by retinoic acid, an active form of provitamin A, but the molecular basis of the biological activities of non-provitamin A carotenoids such as lutein, zeaxanthin, and astaxanthin is not fully understood. In this study, we investigated to determine whether the actions of non-provitamin A carotenoids are mediated via retinoid signaling by monitoring retinoic acid receptor (RAR)-dependent hyaluronan production in cultured human keratinocytes. Not only β-carotene and β-cryptoxanthin, but also lutein, zeaxanthin, and astaxanthin, upregulated HAS3 gene expression and were followed by hyaluronan synthesis. We found that LE540, an antagonist of retinoic acid receptors, abolished lutein dependent hyaluronan synthesis and that lutein significantly increased retinoic acid responsive element (RARE)-driven transcript acitivity. In addition, we found that citral, an inhibitor of retinal dehydrogenases, decreased lutein-stimulated hyaluronan synthesis, indicating that lutein metabolites rather than lutein itself act as an RAR ligand in RAR-mediated transcription activity in keratinocytes. A series of non-provitamin A can be substituted for retinoids and should be considered as a potential means of improving skin health.
The immune-regulatory compound histamine is involved in the metabolism of the essential skin component hyaluronan (HA). We previously reported that histamine up-regulates the expression of HYBID (hyaluronan-binding protein involved in hyaluronan depolymerization, also called CEMIP or KIAA1199), which plays a key role in HA degradation. However, no information is available about histamine's effects on HA synthase (HAS) expression, the molecular sizes of HA species produced, and histamine receptors and their signaling pathways in skin fibroblasts. Moreover, histamine's effects on photoaged skin remain elusive. Here, we show that histamine increases HA degradation by up-regulating HYBID and down-regulating HAS2 in human skin fibroblasts in a dose- and time-dependent manner and thereby decreases the total amounts and sizes of newly produced HA. Histamine H1 blocker abrogated the histamine effects on HYBID up-regulation, HAS2 suppression, and HA degradation. Histamine H1 agonist exhibited effects on HA levels, composition, and breakdown similar to those of histamine. Of note, blockade of protein kinase Cδ or PI3K–Akt signaling abolished histamine-mediated HYBID stimulation and HAS2 suppression, respectively. Immunohistochemical experiments revealed a significant ∼2-fold increase in tryptase-positive mast cells in photoaged skin, where HYBID and HAS2 expression levels were increased and decreased, respectively, compared with photoprotected skin. These results indicate that histamine controls HA metabolism by up-regulating HYBID and down-regulating HAS2 via distinct signaling pathways downstream of histamine receptor H1. They further suggest that histamine may contribute to photoaged skin damage by skewing HA metabolism toward degradation. The immune-regulatory compound histamine is involved in the metabolism of the essential skin component hyaluronan (HA). We previously reported that histamine up-regulates the expression of HYBID (hyaluronan-binding protein involved in hyaluronan depolymerization, also called CEMIP or KIAA1199), which plays a key role in HA degradation. However, no information is available about histamine's effects on HA synthase (HAS) expression, the molecular sizes of HA species produced, and histamine receptors and their signaling pathways in skin fibroblasts. Moreover, histamine's effects on photoaged skin remain elusive. Here, we show that histamine increases HA degradation by up-regulating HYBID and down-regulating HAS2 in human skin fibroblasts in a dose- and time-dependent manner and thereby decreases the total amounts and sizes of newly produced HA. Histamine H1 blocker abrogated the histamine effects on HYBID up-regulation, HAS2 suppression, and HA degradation. Histamine H1 agonist exhibited effects on HA levels, composition, and breakdown similar to those of histamine. Of note, blockade of protein kinase Cδ or PI3K–Akt signaling abolished histamine-mediated HYBID stimulation and HAS2 suppression, respectively. Immunohistochemical experiments revealed a significant ∼2-fold increase in tryptase-positive mast cells in photoaged skin, where HYBID and HAS2 expression levels were increased and decreased, respectively, compared with photoprotected skin. These results indicate that histamine controls HA metabolism by up-regulating HYBID and down-regulating HAS2 via distinct signaling pathways downstream of histamine receptor H1. They further suggest that histamine may contribute to photoaged skin damage by skewing HA metabolism toward degradation.
