Ethanol Metabolism and Melanoma.

Malignant melanoma is the deadliest form of skin cancer. Despite significant efforts in sun protection education, melanoma incidence is still rising globally, drawing attention to other socioenvironmental risk factors for melanoma. Ethanol and acetaldehyde (AcAH) are ubiquitous in our diets, medicines, alcoholic beverages, and the environment. In the liver, ethanol is primarily oxidized to AcAH, a toxic intermediate capable of inducing tumors by forming adducts with proteins and DNA. Once in the blood, ethanol and AcAH can reach the skin. Although, like the liver, the skin has metabolic mechanisms to detoxify ethanol and AcAH, the risk of ethanol/AcAH-associated skin diseases increases when the metabolic enzymes become dysfunctional in the skin. This review highlights the evidence linking cutaneous ethanol metabolism and melanoma. We summarize various sources of skin ethanol and AcAH and describe how the reduced activity of each alcohol metabolizing enzyme affects the sensitivity threshold to ethanol/AcAH toxicity. Data from the Gene Expression Omnibus database also show that three ethanol metabolizing enzymes (alcohol dehydrogenase 1B, P450 2E1, and catalase) and an AcAH metabolizing enzyme (aldehyde dehydrogenase 2) are significantly reduced in melanoma tissues.

Alcohol as a Non-UV Social-Environmental Risk Factor for Melanoma.

Although cancer mortality has declined among the general population, the incidence of melanoma continues to rise. While identifying high-risk cohorts with genetic risk factors improves public health initiatives and clinical care management, recognizing modifiable risk factors such as social-environmental risk factors would also affect the methods of patient outreach and education. One major modifiable social-environmental risk factor associated with melanoma is ultraviolet (UV) radiation. However, not all forms of melanoma are correlated with sun exposure or occur in sun-exposed areas. Additionally, UV exposure is rarely associated with tumor progression. Another social-environmental factor, pregnancy, does not explain the sharply increased incidence of melanoma. Recent studies have demonstrated that alcohol consumption is positively linked with an increased risk of cancers, including melanoma. This perspective review paper summarizes epidemiological data correlating melanoma incidence with alcohol consumption, describes the biochemical mechanisms of ethanol metabolism, and discusses how ethanol and ethanol metabolites contribute to human cancer, including melanoma.

Functional Analysis of the Transcriptional Regulator IκB-ζ in Intestinal Homeostasis.

BACKGROUND: The Toll-like receptor signaling pathway contributes to the regulation of intestinal homeostasis through interactions with commensal bacteria. Although the transcriptional regulator IκB-ζ can be induced by Toll-like receptor signaling, its role in intestinal homeostasis is still unclear. AIMS: To investigate the role of IκB-ζ in gut homeostasis. METHODS: DSS-administration induced colitis in control and IκB-ζ-deficient mice. The level of immunoglobulins in feces was detected by ELISA. The immunological population in lamina propria (LP) was analyzed by FACS. RESULTS: IκB-ζ-deficient mice showed severe inflammatory diseases with DSS administration in the gut. The level of IgM in the feces after DSS administration was less in IκB-ζ-deficient mice compared to control mice. Upon administration of DSS, IκB-ζ-deficient mice showed exaggerated intestinal inflammation (more IFN-g-producing CD4+ T cells in LP), and antibiotic treatment canceled this inflammatory phenotype. CONCLUSION: IκB-ζ plays a crucial role in maintaining homeostasis in the gut.

EGCG Inhibits Tumor Growth in Melanoma by Targeting JAK-STAT Signaling and Its Downstream PD-L1/PD-L2-PD1 Axis in Tumors and Enhancing Cytotoxic T-Cell Responses.

Over the last decade, therapies targeting immune checkpoints, such as programmed death-1 (PD-1), have revolutionized the field of cancer immunotherapy. However, low response rates and immune-related adverse events remain a major concern. Here, we report that epigallocatechin gallate (EGCG), the most abundant catechin in green tea, inhibits melanoma growth by modulating an immune response against tumors. In vitro experiments revealed that EGCG treatment inhibited interferon-gamma (IFN-γ)-induced PD-L1 and PD-L2 expression and JAK-STAT signaling. We confirmed that this effect was driven by inhibiting STAT1 gene expression and STAT1 phosphorylation, thereby downregulating the PD-L1/PD-L2 transcriptional regulator IRF1 in both human and mouse melanoma cells. Animal studies revealed that the in vivo tumor-inhibitory effect of EGCG was through CD8+ T cells and that the inhibitory effect of EGCG was comparable to anti-PD-1 therapy. However, their mechanisms of action were different. Dissimilar to anti-PD-1 treatment that blocks PD-1/PD-L1 interaction, EGCG inhibited JAK/STAT signaling and PD-L1 expression in tumor cells, leading to the re-activation of T cells. In summary, we demonstrate that EGCG enhances anti-tumor immune responses by inhibiting JAK-STAT signaling in melanoma. EGCG could be used as an alternative treatment strategy to target the PD-L1/PD-L2-PD-1 axis in cancers.

Reduced concentrations of the B cell cytokine interleukin 38 are associated with cardiovascular disease risk in overweight subjects.

The IL-1 family member IL-38 (IL1F10) suppresses inflammatory and autoimmune conditions. Here, we report that plasma concentrations of IL-38 in 288 healthy Europeans correlate positively with circulating memory B cells and plasmablasts. IL-38 correlated negatively with age (p = 0.02) and was stable in 48 subjects for 1 year. In comparison with primary keratinocytes, IL1F10 expression in CD19+ B cells from PBMC was lower, whereas cell-associated IL-38 expression was comparable. In vitro, IL-38 is released from CD19+ B cells after stimulation with rituximab. Intravenous LPS in humans failed to induce circulating IL-38, compared to 100-fold induction of IL-6 and IL-1 receptor antagonist. In a cohort of 296 subjects with body mass index > 27 at high risk for cardiovascular disease, IL-38 plasma concentrations were significantly lower than in healthy subjects (p < 0.0001), and lowest in those with metabolic syndrome (p < 0.05). IL-38 also correlated inversely with high sensitivity C-reactive protein (p < 0.01), IL-6, IL-1Ra, and leptin (p < 0.05). We conclude that a relative deficiency of the B cell product IL-38 is associated with increased systemic inflammation in aging, cardiovascular and metabolic disease, and is consistent with IL-38 as an anti-inflammatory cytokine.

TLR3 augments glucocorticoid-synthetic enzymes expression in epidermal keratinocytes; Implications of glucocorticoid metabolism in rosacea epidermis.

BACKGROUND: While most skin diseases benefit from topical steroids, rosacea symptoms are exacerbated by topical steroids. In the rosacea pathogenesis, abnormal innate immune mechanisms including overexpression of the Toll-like receptor (TLR) have been proposed. However, the links between glucocorticoid metabolism and innate immunity in the epidermis have not been elucidated. OBJECTIVE: In order to understand the pathology by which rosacea symptoms are exacerbated by steroids and environment stimuli, we examined the molecular links between the innate immune system and glucocorticoid synthesis in epidermis. METHODS: We examined the expression of glucocorticoid-synthetic enzymes in rosacea skin. We stimulated epidermal keratinocytes by TLR ligands and examined the regulation of glucocorticoid-synthetic enzymes. We also employed siRNA and adenovirus vectors to knockdown and transduce TLR molecules, respectively. RESULTS: Rosacea epidermis showed high HSD11B1 in the granular layer. Among TLR ligands, TLR3 ligand Poly(I:C) enhanced the expression of multiple glucocorticoid-synthetic enzymes including HSD11B1 and CYP11A1, and increased cortisol in the cultured media. Induction of HSD11B1 by Poly(I:C) was abolished by pretreatment with TLR3 siRNA. Transfection with an adenoviral vector incorporating TLR3 enhanced HSD11B1 and CYP11A1 protein expression by Poly(I:C). In addition, cell staining revealed increased expression of HSD11B1 and CYP11A1 proteins in the group transfected with TLR3 under the same conditions. CONCLUSION: TLR3-stimulated epidermal keratinocytes and rosacea epidermis enhance the expression of glucocorticoid-synthetic enzymes, which would promote cortisol activation in the epidermis. The innate immunity modulates glucocorticoid-synthetic enzymes expression via the TLR3 pathway in epidermal keratinocytes.

Inflammasome Sensor NLRP1 Confers Acquired Drug Resistance to Temozolomide in Human Melanoma.

Cancer cells gain drug resistance through a complex mechanism, in which nuclear factor-κB (NF-κB) and interleukin-1ß (IL-1ß) are critical contributors. Because NACHT, LRR and PYD domains-containing protein (NLRP) inflammasomes mediate IL-1ß maturation and NF-κB activation, we investigated the role of inflammasome sensor NLRP1 in acquired drug resistance to temozolomide (TMZ) in melanoma. The sensitivity of melanoma cells to TMZ was negatively correlated with the expression levels of O6-methylguanine-DNA methyltransferase (MGMT), the enzyme to repair TMZ-induced DNA lesions. When MGMT-low human melanoma cells (1205Lu and HS294T) were treated with TMZ for over two months, MGMT was upregulated, and cells became resistant. However, the resistance mechanism was independent of MGMT, and the cells that acquired TMZ resistance showed increased NLRP1 expression, NLRP inflammasome activation, IL-1ß secretion, and NF-κB activity, which contributed to the acquired resistance to TMZ. Finally, blocking IL-1 receptor (IL-1R) signaling with IL-1R antagonist decreased TMZ-resistant 1205Lu tumor growth in vivo. Although inflammation has been associated with drug resistance in various cancers, our paper is the first to demonstrate the involvement of NLRP in the development of acquired drug resistance. Because drug-tolerant cancer cells become cross-tolerant to other classes of cancer drugs, NLRP1 might be a suitable therapeutic target in drug-resistant melanoma, as well as in other cancers.

Bucillamine Inhibits UVB-Induced MAPK Activation and Apoptosis in Human HaCaT Keratinocytes and SKH-1 Hairless Mouse Skin.

Ultraviolet B (UVB) radiation is known as a culprit in skin carcinogenesis. We have previously reported that bucillamine (N-[2-mercapto-2-methylpropionyl]-L-cysteine), a cysteine derivative with antioxidant and anti-inflammatory capacity, protects against UVB-induced p53 activation and inflammatory responses in mouse skin. Since MAPK signaling pathways regulate p53 expression and activation, here we determined bucillamine effect on UVB-mediated MAPK activation in vitro using human skin keratinocyte cell line HaCaT and in vivo using SKH-1 hairless mouse skin. A single low dose of UVB (30 mJ cm-2 ) resulted in increased JNK/MAPK phosphorylation and caspase-3 cleavage in HaCaT cells. However, JNK activation and casaspe-3 cleavage were inhibited by pretreatment of HaCaT cells with physiological doses of bucillamine (25 and 100 µm). Consistent with these results, bucillamine pretreatment in mice (20 mg kg-1 ) inhibited JNK/MAPK and ERK/MAPK activation in skin epidermal cells at 6-12 and 24 h, respectively, after UVB exposure. Moreover, bucillamine attenuated UVB-induced Ki-67-positive cells and cleaved caspase-3-positive cells in mouse skin. These findings demonstrate that bucillamine inhibits UVB-induced MAPK signaling, cell proliferation and apoptosis. Together with our previous report, we provide evidence that bucillamine has a photoprotective effect against UV exposure.

TLR3 stimulation induces melanosome endo/phagocytosis through RHOA and CDC42 in human epidermal keratinocyte.

BACKGROUND: Keratinocytes and melanocytes in human epidermis express Toll-like receptors (TLR) and induce immune responses. We previously reported that TLR3 stimulation increases melanosome transport from perinuclear to cell membrane in melanocytes and enhanced release of melanosome from melanocytes, which were followed by increase in melanosome uptake into keratinocytes. OBJECTIVE: In this study, we investigated whether TLR3 stimuli directly affect keratinocytes to enhance melanosome uptake. METHODS: To observe keratinocyte's melanosome uptake ability precisely without melanocytes influences, we isolated melanosomes from human melanocytes and applied isolated melanosomes to keratinocytes stimulated by Poly(I:C). RESULTS: Poly(I:C)-stimulated keratinocytes enhanced uptake of isolated melanosome-rich globules five-times as much as control. Poly(I:C) increases the RNA and protein expressions of RHOA and CDC42, which are small GTP-binding proteins inducing the endocytosis. Pull-down assay showed that Poly(I:C) increased the GTP-binding RHOA and CDC42, suggesting TLR3 stimulation activated RHOA and CDC42. The knockdown of TLR3 suppressed RHOA and CDC42 induction by Poly(I:C). Consistently, the knockdown of RHOA and CDC42 significantly suppressed the melanosome-rich globules uptake by Poly(I:C)-stimulated keratinocytes. CONCLUSION: Because RHOA and CDC42 activation induces endocytosis by modification of actin stress fiber and filopodia formation, respectively, these results suggested that TLR3 stimulation enhances melanosome uptake into keratinocytes through endocytosis mechanisms. Combining with the data of our previous publications, TLR3, which signal is activated by sensing viral molecules, enhance pigmentation by controlling both melanin transport system by RAB GTPases induction in melanocytes and uptake system by RHOA and CDC42 in keratinocytes.

Red light-promoted skin barrier recovery: Spatiotemporal evaluation by transepidermal potential.

The light-promoted recovery of epidermal barrier of skin was evaluated by the associated recovery of transepidermal potential (TEP), the potential difference between the surface and dermis of skin, by using porcine skin samples. An accelerated recovery of TEP was observed by irradiation of red light with the irradiance of 40 mW/cm2 and a duration of > 10 min. The influence of the light stimulation to the surroundings (~ 20 mm) was also observed. The irradiations of blue and purple lights were ineffective in accelerating the barrier recovery. These characteristics of the light stimulation would be useful for the design of effective and safe phototherapy devices for skin. The present study proves that the TEP can serve as a spatiotemporal indicator of the epidermal barrier function.

Androgens modulate keratinocyte differentiation indirectly through enhancing growth factor production from dermal fibroblasts.

BACKGROUND: The main pathogenesis of acne vulgaris is increase in sebum production and abnormal keratinization of the hair infundibulum. The androgens are involved in acne pathogenesis by modulating sebaceous glands to enhance sebum production. However, the molecular mechanisms of abnormal keratinization of the hair infundibulum are not fully elucidated. OBJECTIVE: We hypothesized that the androgens affect the dermal fibroblasts, another androgen receptor-positive cells in the skin, resulting in abnormal keratinization through keratinocyte-fibroblast interaction. METHODS: We investigated effects of androgens and estrogens on growth factors expressions by RT-PCR and western blot analysis in human fibroblast (hFB), human keratinocyte (hKC), and fibroblast-keratinocyte co-culture. In vivo, we examined the growth factor expression in acne lesions compared to normal hair follicles by laser-assisted confocal microscope. RESULTS: In vitro, androgens but not estrogens significantly increased amphiregulin (AREG), epiregulin (EREG), fibroblast growth factor (FGF) 10, and insulin-like growth factor binding protein (IGFBP) 5 mRNA and protein expressions in human fibroblasts but not in keratinocytes. In vivo, AREG, EREG, FGF10, and IGFBP5 were more abundant in acne lesion compared to normal facial skin. FGF10 suppressed cytokeratin 1 and cytokeratin 10 expression in hKC, which was along with the decreased ratio of cytokeratin 10 against cytokeratin 14 in acne lesions compared to normal facial skin. Also, DHT suppressed cytokeratin 1 and cytokeratin 10, in fibroblast-keratinocyte co-culture similarly to the effect of FGF10 to hKC. CONCLUSION: These observations suggested that androgens enhance growth factors production from dermal fibroblasts, and growth factors from fibroblasts alter keratinocyte differentiation in acne lesion.

Anti melanogenic effect of Croton roxburghii and Croton sublyratus leaves in α-MSH stimulated B16F10 cells.

Croton roxburghii and Croton sublyratus have been used as skin treatments in traditional medicine. The objective of the present study was to investigate the antimelanogenic effect of ethanol extracts of Croton roxburghii (CRE) and Croton sublyratus (CSE) leaves on cellular melanin content and cellular tyrosinase activity as mediated by the action of microthalmia transcription factor (MITF) and melanogenic enzymes. Croton roxburghii and Croton sublyratus leaves were extracted by petroleum ether, dichloromethane and absolute ethanol, sequentially. The ethanolic crude extracts were examined for antimelanogenic activity by their ability to decrease melanin content and cellular tyrosinase activity in alpha-melanocyte-stimulating hormone-stimulated B16F10 melanoma cells. In addition, the extracts were evaluated to determine a plausible mechanism of melanogenesis suppression through determining the activation of MITF transcription factor and melanogenic proteins (tyrosinase, tyrosinase-related protein 1 or TRP-1 and tyrosinase-related protein 2 or TRP-2) at the transcriptional and translation levels in α-MSH-induced B16F10 cells. Upon treatment with CRE and CSE, the cells showed significant decreases in melanin content and cellular tyrosinase activity. CRE and CSE also suppressed MITF, tyrosinase, TRP-1 and TRP-2 at the transcription and translation levels in α-MSH-stimulated melanin biosynthesis in B16F10 cells. Our finding shows that CRE and CSE inhibit melanin content and cellular tyrosinase activity through suppressing MITF and melanogenic enzymes. CRE and CSE may be useful to combine with skin whitening agents for cosmetic uses.

Artificial Pigmented Human Skin Created by Muse Cells.

The skin composes physiological and chemical barrier and renews skin component cells throughout the human life. Melanocytes locate in the basal layer of the epidermis and produce melanin to protect the skin from ultraviolet. Melanin plays key roles in determining human skin and hair color. Melanocyte dysfunction observed in albinism and vitiligo not only causes cosmetic problems but also increases risk of skin cancer. As rejuvenate therapy, embryonic stem (ES) cells and induced pluripotent stem (iPS) cells have been reported to generate melanocytes. Other than ES and iPS cells, human skin tissues maintain pluripotent stem cells, named multilineage-differentiating stress-enduring (Muse) cells. We employ Muse cells isolated from human fibroblasts and adipose tissue to differentiate into melanocytes (Muse-MC). Muse-MC express melanocyte-related molecules, such as tyrosinase and DCT, and show tyrosinase activity. We also succeeded to differentiate Muse cells into fibroblasts and keratinocytes and created three-dimensional (3D) reconstituted skin with Muse cell-derived melanocytes, fibroblasts, and keratinocytes. The 3D reconstituted skin of Muse cell-derived cells coordinately showed epidermis layers and Muse-MC localized in the basal layer of the epidermis. Thus Muse cells in the human skin can be a source of rejuvenation medicine for the skin reconstruction.

Effects of promoting daily physical activity on physical and mental health in older individuals.

[Purpose] A trial was conducted to examine the effects of promoting daily physical activity, tailored to specific living situations, on physical and mental health indicators in older adults. [Participants and Methods] Participants in the 'Intervention' group (N=21) wore accelerometers during the 12-week trial period, and for one week during preliminary and follow-up surveys. Based on their physical activity levels as measured by accelerometers, participants were given instructions to increase their daily physical activity. Participants in the 'Control' group (N=18) wore the accelerometer only during the preliminary and follow-up survey. [Results] Number of steps increased significantly in the intervention group and a significant decrease in light physical activity time was observed in the control group. No such decrease was observed in the intervention group. With regard to health-related quality of life, significant interactions were observed between groups based on the 36-Item Short-Form Health Survey Mental Component Summary score, and some sub-items. A combined analysis of both groups found a significant positive correlation between the change in light physical activity time and the Mental Component Summary score. [Conclusion] An increase in daily physical activity was considered to have a sustained bolstering effect on mental health.

Toll-like receptors 2 and 3 enhance melanogenesis and melanosome transport in human melanocytes.

Because little is known about how the innate immune response influences skin pigmentation, we examined whether Toll-like receptor (TLR) agonists participate in melanogenesis and melanosome transportation. We observed that TLR2/2 agonist HKLM and TLR3 agonist Poly(I:C) increased the amount of extracellular melanin from primary human epidermal melanocytes. HKLM, but not Poly(I:C), increased the melanogenic genes such as tyrosinase and dopachrome tautomerase. Poly(I:C) increased the expression of Rab27A, a molecule that facilitates melanosome transport to perimembranous actin filament. UVB irradiation induced Rab27A and melanosome transportation in a similar manner of Poly(I:C). SiRNA for TLR3 or Rab27A suppressed the perimembranous accumulation of Gp100-positive vesicles in melanocytes and decreased melanin transfer to neighboring keratinocytes induced by both Poly(I:C) and UVB. These results suggest that the microenvironment in the epidermis and innate immune stimuli, such as microbiome and ultraviolet represented here by TLR2 and TLR3 agonists, could affect the melanogenesis in human melanocytes.

Comparable prognostic impact of BNP levels among HFpEF, Borderline HFpEF and HFrEF: a report from the CHART-2 Study.

We aimed to compare the usefulness of plasma levels of B-type natriuretic peptide (BNP) for long-term risk stratification among patients with heart failure (HF) with preserved left ventricular ejection fraction (LVEF) (HFpEF), borderline HFpEF, and HF with reduced LVEF (HFrEF) in the same HF cohort. In the CHART-2 Study (N = 10,219), we categorized 4301 consecutive Stage C/D HF patients (mean age 68.7 years, female 32.4%) into 3 groups: HFpEF (LVEF ≥ 50%, N = 2893), borderline HFpEF (LVEF 40-50%, N = 666), and HFrEF (LVEF ≤ 40%, N = 742). During the median 6.3-year follow-up, all-cause deaths occurred in 887 HFpEF, 330 borderline HFpEF, and 330 HFrEF patients. Although median BNP levels increased from HFpEF, borderline HFpEF to HFrEF (85.3, 126 and 208 pg/ml, respectively, P < 0.001), the relationship between log2 BNP levels and the mortality risk was comparable among the 3 groups. As compared with patients with BNP < 30 pg/ml, those with 30-99, 100-299 and ≥ 300 pg/ml had comparably increasing mortality risk among the 3 groups (hazard ratio 2.5, 4.7 and 7.8 in HFpEF, 2.1, 4.2 and 7.0 in borderline HFpEF, and 3.0, 4.7 and 9.5 in HFrEF, respectively, all P < 0.001). BNP levels have comparable prognostic impact among HFpEF, borderline HFpEF, and HFrEF patients.

Accelerated Wound Healing on Skin by Electrical Stimulation with a Bioelectric Plaster.

Wound healing on skin involves cell migration and proliferation in response to endogenous electric current. External electrical stimulation by electrical equipment is used to promote these biological processes for the treatment of chronic wounds and ulcers. Miniaturization of the electrical stimulation device for wound healing on skin will make this technology more widely available. Using flexible enzymatic electrodes and stretchable hydrogel, a stretchable bioelectric plaster is fabricated with a built-in enzymatic biofuel cell (EBFC) that fits to skin and generates ionic current along the surface of the skin by enzymatic electrochemical reactions for more than 12 h. To investigate the efficacy of the fabricated bioelectric plaster, an artificial wound is made on the back skin of a live mouse and the wound healing is observed for 7 d in the presence and absence of the ionic current of the bioelectric plaster. The time course of the wound size as well as the hematoxylin and eosin staining of the skin section reveals that the ionic current of the plaster leads to faster and smoother wound healing. The present work demonstrates a proof of concept for the electrical manipulation of biological functions by EBFCs.