The biological actions of estrogens on skin

The Relative Importance of Sexual Dimorphism, Fluctuating Asymmetry, and Color Cues to Health during Evaluation of Potential Partners' Facial Photographs : A Conjoint Analysis Study

Sexual dimorphism, symmetry, and coloration in human faces putatively signal information relevant to mate selection and reproduction. Although the independent contributions of these characteristics to judgments of attractiveness are well established, relatively few studies have examined whether individuals prioritize certain features over others. Here, participants (N = 542, 315 female) ranked six sets of facial photographs (3 male, 3 female) by their preference for starting long- and short-term romantic relationships with each person depicted. Composite-based digital transformations were applied such that each image set contained 11 different versions of the same identity. Each photograph in each image set had a unique combination of three traits: sexual dimorphism, symmetry, and color cues to health. Using conjoint analysis to evaluate participants' ranking decisions, we found that participants prioritized cues to sexual dimorphism over symmetry and color cues to health. Sexual dimorphism was also found to be relatively more important for the evaluation of male faces than for female faces, whereas symmetry and color cues to health were relatively more important for the evaluation of female faces than for male faces. Symmetry and color cues to health were more important for long-term versus short-term evaluations for female faces, but not male faces. Analyses of utility estimates reveal that our data are consistent with research showing that preferences for facial masculinity and femininity in male and female faces vary according to relationship context. These findings are interpreted in the context of previous work examining the influence of these facial attributes on romantic partner perception.

Testosterone Prevents Cutaneous Ischemia and Necrosis in Males Through Complementary Estrogenic and Androgenic Actions

OBJECTIVE

Chronic nonhealing wounds are a substantial medical concern and are associated with morbidity and mortality; thus, new treatment strategies are required. The first step toward personalized/precision medicine in this field is probably in taking sex differences into account. Impaired wound healing is augmented by ischemia, and we previously demonstrated that 17β-estradiol exerts a major preventive effect against ischemia-induced skin flap necrosis in female mice. However, the equivalent effects of testosterone in male mice have not yet been reported. We then investigated the role of steroid hormones in male mice using a skin flap ischemia model.

APPROACH AND RESULTS

Castrated male mice developed skin necrosis after ischemia, whereas intact or castrated males treated with testosterone were equally protected. Testosterone can (1) activate the estrogen receptor after its aromatization into 17β-estradiol or (2) be reduced into dihydrotestosterone, a nonaromatizable androgen that activates the androgen receptor. We found that dihydrotestosterone protected castrated wild-type mice by promoting skin revascularization, probably through a direct action on resistance arteries, as evidenced using a complementary model of flow-mediated outward remodeling. 17β-estradiol treatment of castrated male mice also strongly protected them from ischemic necrosis through the activation of estrogen receptor-α by increasing skin revascularization and skin survival. Remarkably, 17β-estradiol improved skin survival with a greater efficiency than dihydrotestosterone.

CONCLUSIONS

Testosterone provides males with a strong protection against cutaneous necrosis and acts through both its estrogenic and androgenic derivatives, which have complementary effects on skin survival and revascularization.

Cutaneous melanoma in women

BACKGROUND

Gender disparity in melanoma outcome is consistently observed, suggesting that gender is as an important prognostic factor. However, the source of this gender disparity in melanoma remains unclear.

OBJECTIVE

This article reviews advances in our understanding of gender differences in melanoma and how such differences may contribute to outcomes.

METHODS

A broad literature search was conducted using the PubMed database, with search terms such as 'gender differences in melanoma' and 'sex differences in melanoma.' Additional articles were identified from cited references.

RESULTS

Herein, we address the gender-linked physiologic differences in skin and melanoma. We discuss the influence of estrogen on a woman's risk for melanoma and melanoma outcomes with regard to pregnancy, oral contraceptives, hormone replacement therapy, and UV tanning.

CONCLUSIONS

The published findings on gender disparities in melanoma have yielded many advances in our understanding of this disease. Biological, environmental, and behavioral factors may explain the observed gender difference in melanoma incidence and outcome. Further research will enable us to learn more about melanoma pathogenesis, with the goal of offering better treatments and preventative advice to our patients.

Facial redness, expression, and masculinity influence perceptions of anger and health

Past research has found that skin colouration, particularly facial redness, influences the perceived health and emotional state of target individuals. In the current work, we explore several extensions of this past research. In Experiment 1, we manipulated facial redness incrementally on neutral and angry faces and had participants rate each face for anger and health. Different red effects emerged, as perceived anger increased in a linear manner as facial redness increased. Health ratings instead showed a curvilinear trend, as both extreme paleness and redness were rated as less healthy than moderate levels of red. Experiment 2 replicated and extended these findings by manipulating the masculinity of both angry and neutral faces that varied in redness. The results found the effect of red on perceived anger and health was moderated by masculine face structure. Collectively, these results show that facial redness has context dependent effects that vary based on facial expression, appearance, and differentially impact ratings of emotional states and health.

Expression of estrogen and progesterone receptors across human malignancies: new therapeutic opportunities

Estrogen and progesterone receptors (ERs and PRs) are known for their prognostic as well as treatment predictive value in breast cancer. Although these receptors are differentially expressed in some other malignancies, and likely participate in the biology of those cancer types, the relevance to outcome and therapy is not well established. The use of ER as a highly effective therapeutic target in oncology was pioneered in breast cancer, and the lessons learned from its success could potentially benefit patients with several other malignancies in which hormone receptors are highly expressed. Indeed, there are several potent drugs available that target hormone receptors. These agents show incontrovertible evidence of benefit in patients with hormone receptor-positive breast cancer. It is conceivable that these drugs may have salutary effects in a variety of cancers other than those originating in the breast, based on the overexpression of hormone receptors in some patients, and the preclinical and clinical reports showing responses to these drugs in diverse cancers, albeit in small series or anecdotally. We therefore undertook a literature review in order to summarize the current data regarding the biologic and clinical implications of expression of estrogen and progesterone receptors in various malignancies and the possibilities for deployment of hormone manipulation beyond breast cancer.

Intrinsic versus Extrinsic Aging: A Histopathological, Morphometric and Immunohistochemical Study of Estrogen Receptor β and Androgen Receptor

Skin is a target organ of sex steroids which play important roles in skin health and disease. The aim of this study is to investigate the expression of estrogen receptor β (ERβ) and androgen receptor (AR) in human skin from different age groups for a better understanding of the hormonal regulation of skin aging. Using standard immunohistochemical techniques, biopsies of sun-unprotected and sun-protected skin were taken from 60 normal subjects. Sun-protected skin showed significantly higher immunoreactivity for ERβ and AR compared to sun-unprotected skin of all age groups. Significantly higher ERβ H score and percent of expression were associated with the 20-35 years age group compared to the groups that were 35-50 years and >50 years old (p < 0.02, p = 0.03, respectively) in sun-unprotected and sun-protected skin (p < 0.001, p = 0.01, respectively). AR H score showed a negative correlation with age (p = 0.04) with no significant difference in immunoreactivity in different age groups, either in sun-unprotected or sun-protected skin. There was also a significant correlation between ERβ H score and epidermal thickness in sun-unprotected (p = 0.04) and sun-protected skin (p = 0.04) in studied subjects regardless of age. The same relationships did not reach significance with AR expression. However, a significant positive correlation was detected between H scores and percent of expression of ERβ and AR in sun-unprotected (p = 0.01, p = 0.02, respectively) and sun-protected skin (p = 0.005, p = 0.02, respectively) regardless of age. In conclusion, both ERβ and AR decline gradually with intrinsic and extrinsic aging. This decline is more obvious with extrinsic aging. Further large-scaled studies are recommended to expand, validate and translate current findings to clinically significant, diagnostic and therapeutic applications. Molecular studies to investigate the probable ligand-independent action of both receptors are warranted. In addition, their gene expression patterns and associated signaling and metabolic pathways can also be tackled to provide a basis for further interventions in pathological processes that involve their dysregulation.

Estrogen receptor β in Merkel cell carcinoma: its possible roles in pathogenesis

Sex steroids have been postulated to influence skin development and functions as well as its pathogenesis. MCC occurs in both sexes; however, the specific differences in pathogenesis among sexes have yet to be conclusively defined. The detailed status of sex steroid receptors (AR, PRA and PRB, and ERα, ERβ) are also unknown in MCC patients. We first immunolocalized sex steroid receptors and compared the results with immunolocalization of relevant transcription factors including SOX2, FOXA1, and Bcl-2 and Ki-67 in 18 cases of MCCs. AR, PRA, PRB, ERα, ERβ, Bcl-2, SOX2, and FOXA1 immunoreactivity was evaluated by using the modified H score method, and Ki-67 was quantified using labeling index. ERβ immunoreactivity was markedly present in all the cases of MCC examined, with relatively weak immunoreactivity of ERα, AR, PRA, and PRB. The status of ERβ immunoreactivity was also significantly correlated with Ki-67 labeling index and Bcl-2 score. These results demonstrated that ERβ could be associated with regulation of both cell proliferation and apoptosis in MCCs.

Sex-specific genetic effects associated with pigmentation, sensitivity to sunlight, and melanoma in a population of Spanish origin

BACKGROUND

Human pigmentation is a polygenic quantitative trait with high heritability. In addition to genetic factors, it has been shown that pigmentation can be modulated by oestrogens and androgens via up- or down-regulation of melanin synthesis. Our aim was to identify possible sex differences in pigmentation phenotype as well as in melanoma association in a melanoma case-control population of Spanish origin.

METHODS

Five hundred and ninety-nine females (316 melanoma cases and 283 controls) and 458 males (234 melanoma cases and 224 controls) were analysed. We genotyped 363 polymorphisms (single nucleotide polymorphisms (SNPs)) from 65 pigmentation gene regions.

RESULTS

When samples were stratified by sex, we observed more SNPs associated with dark pigmentation and good sun tolerance in females than in males (107 versus 75; P = 2.32 × 10(-6)), who were instead associated with light pigmentation and poor sun tolerance. Furthermore, six SNPs in TYR, SILV/CDK2, GPR143, and F2RL1 showed strong differences in melanoma risk by sex (P < 0.01).

CONCLUSIONS

We demonstrate that these genetic variants are important for pigmentation as well as for melanoma risk, and also provide suggestive evidence for potential differences in genetic effects by sex.

Review of recent research on biomedical applications of electrospun polymer nanofibers for improved wound healing

Wound dressings play an important role in a patient's recovery from health problems, as unattended wounds could lead to serious complications such as infections or, ultimately, even death. Therefore, wound dressings since ancient times have been continuously developed, starting from simple dressings from natural materials for covering wounds to modern dressings with functionalized materials to aid in the wound healing process and enhance tissue repair. However, understanding the nature of a wound and the subsequent healing process is vital information upon which dressings can be tailored to ensure a patient's recovery. To date, much progress has been made through the use of nanomedicine in wound healing due to the ability of such materials to mimic the natural dimensions of tissue. This review provides an overview of recent studies on the physiology of wound healing and various wound dressing materials made of nanofibers fabricated using the electrospinning technique.

[Skin aging and evidence-based topical strategies]

Anti-aging in dermatology primarily focuses on the prevention of skin aging with UV protection (clothing and sunsceens), free radical scavengers (synthetic or botanic), and cell-protecting agents such as vitamin B3. For the correction of signs of early skin aging, retinoic acid derivatives in dermatological prescriptions are the best studied substances. Topical hormonal prescriptions are also an option if UV damage has not been the leading culprit for aging. Chemical peeling leads to a marked increase in collagen formation, the deaper the better. Ingredients in cream preparations can reduce superficial skin folds (polyphenols, amino acid peptides). Modulators of regular pigmentation are important for anti-aging preparations. Growth factors (plant extracts, recombinant growth factors) are not thoroughly studied regarding the cost-benefit and risk ratio. Complex precedures such as photodynamic therapy have an impact on the appearance of aged skin.

Female Estrogen-Related Factors and Incidence of Basal Cell Carcinoma in a Nationwide US Cohort

Purpose

UV radiation exposure is the primary risk factor for basal cell carcinoma (BCC), the most common human malignancy. Although the photosensitizing properties of estrogens have been recognized for decades, few studies have examined the relationship between reproductive factors or exogenous estrogen use and BCC.

Methods

Using data from the US Radiologic Technologists Study, a large, nationwide, prospective cohort, we assessed the relationship between reproductive factors, exogenous estrogen use, and first primary BCC while accounting for sun exposure, personal sun sensitivity, and lifestyle factors for geographically dispersed women exposed to a wide range of ambient UV radiation.

Results

Elevated risk of BCC was associated with late age at natural menopause (hazard ratio [HR] for ≥ 55 years v 50 to 54 years, 1.50; 95% CI, 1.04 to 2.17) and any use of menopausal hormone therapy (MHT; HR, 1.16; 95% CI, 1.03 to 1.30; P for trend for duration = .001). BCC risk was most increased among women reporting natural menopause who used MHT for 10 or more years versus women who never used MHT (HR, 1.97; 95% CI, 1.35 to 2.87). Risk of BCC was not associated with age at menarche, parity, age at first birth, infertility, use of diethylstilbestrol by participant's mother, age at hysterectomy, or use of oral contraceptives.

Conclusion

These analyses confirm a previous finding of increased risk of BCC associated with MHT. Novel findings of increased BCC risk associated with MHT in women experiencing natural menopause and for late age at natural menopause warrant further investigation. Users of MHT may constitute an additional high-risk group in need of more frequent skin cancer screening.

Recent progress in melasma pathogenesis

Melasma is a common skin pigmentation condition. Given therapeutic difficulty as one of the biggest concerns, understanding of the etiology and pathogenesis of melasma becomes essential. UV irradiation, female sex hormones, and inflammatory processes are addressed as triggering factors with genetic predisposition. The mechanism of UV-induced melanogenesis has been extensively investigated as a model system to study melasma pathogenesis. Hitherto, treatment modalities for melasma are similar to other hyperpigmentation disorders. However, individual triggering factors induce a separate pigmentation disease, whose pathogenic mechanisms and clinical phenotypes are different from the ones encountered in melasma. Fortunately, there have been ongoing updates on melasma pathogenesis with regard to major triggering factors. Presence of certain factors working independently of UV exposure and role of dermal factors and microRNAs are being identified as novel discoveries about melasma pathogenesis. In this review, the melasma pathogenesis is reviewed in association with updated and new findings.

Fibroblast heterogeneity and its implications for engineering organotypic skin models in vitro

Advances in cell culture methods, multidisciplinary research, clinical need to replace lost skin tissues and regulatory need to replace animal models with alternative test methods has led to development of three dimensional models of human skin. In general, these in vitro models of skin consist of keratinocytes cultured over fibroblast-populated dermal matrices. Accumulating evidences indicate that mesenchyme-derived signals are essential for epidermal morphogenesis, homeostasis and differentiation. Various studies show that fibroblasts isolated from different tissues in the body are dynamic in nature and are morphologically and functionally heterogeneous subpopulations. Further, these differences seem to be dictated by the local biological and physical microenvironment the fibroblasts reside resulting in "positional identity or memory". Furthermore, the heterogeneity among the fibroblasts play a critical role in scarless wound healing and complete restoration of native tissue architecture in fetus and oral mucosa; and excessive scar formation in diseased states like keloids and hypertrophic scars. In this review, we summarize current concepts about the heterogeneity among fibroblasts and their role in various wound healing environments. Further, we contemplate how the insights on fibroblast heterogeneity could be applied for the development of next generation organotypic skin models.

Eph receptor and ephrin function in breast, gut, and skin epithelia

Epithelial cells are tightly coupled together through specialized intercellular junctions, including adherens junctions, desmosomes, tight junctions, and gap junctions. A growing body of evidence suggests epithelial cells also directly exchange information at cell-cell contacts via the Eph family of receptor tyrosine kinases and their membrane-associated ephrin ligands. Ligand-dependent and -independent signaling via Eph receptors as well as reverse signaling through ephrins impact epithelial tissue homeostasis by organizing stem cell compartments and regulating cell proliferation, migration, adhesion, differentiation, and survival. This review focuses on breast, gut, and skin epithelia as representative examples for how Eph receptors and ephrins modulate diverse epithelial cell responses in a context-dependent manner. Abnormal Eph receptor and ephrin signaling is implicated in a variety of epithelial diseases raising the intriguing possibility that this cell-cell communication pathway can be therapeutically harnessed to normalize epithelial function in pathological settings like cancer or chronic inflammation.

Characterization of a Hormone-Responsive Organotypic Human Vaginal Tissue Model: Morphologic and Immunologic Effects

Estrogen and progesterone regulate proliferation and differentiation of epithelial cells in the female genital tract. We investigated the effects of these hormones on reconstructed human organotypic vaginal epithelial tissue models (EpiVaginal). We ascertained that epithelial cells in the tissue models express estrogen and progesterone receptors. Treatment with estradiol-17β (E(2)) significantly increased epithelium thickness and transepithelial electrical resistance (TEER), whereas progesterone (P) treatment resulted in thinning of the epithelium and decreased TEER when compared with untreated controls. Exposure to E(2) increased (1) the expression of the progesterone receptor B (PR-B), (2) accumulation of glycogen in suprabasal cells, (3) epithelial differentiation, and (4) the expression of a number of gene pathways associated with innate immunity, epithelial differentiation, wound healing, and antiviral responses. These findings indicate that EpiVaginal tissues are hormone responsive and can be used to study the role of female reproductive hormones in innate immune responses, microbial infection, and drug delivery in the vaginal mucosa.

Changes in Women's Facial Skin Color over the Ovulatory Cycle are Not Detectable by the Human Visual System

Human ovulation is not advertised, as it is in several primate species, by conspicuous sexual swellings. However, there is increasing evidence that the attractiveness of women's body odor, voice, and facial appearance peak during the fertile phase of their ovulatory cycle. Cycle effects on facial attractiveness may be underpinned by changes in facial skin color, but it is not clear if skin color varies cyclically in humans or if any changes are detectable. To test these questions we photographed women daily for at least one cycle. Changes in facial skin redness and luminance were then quantified by mapping the digital images to human long, medium, and shortwave visual receptors. We find cyclic variation in skin redness, but not luminance. Redness decreases rapidly after menstrual onset, increases in the days before ovulation, and remains high through the luteal phase. However, we also show that this variation is unlikely to be detectable by the human visual system. We conclude that changes in skin color are not responsible for the effects of the ovulatory cycle on women's attractiveness.

Increased facial attractiveness following moderate, but not high, alcohol consumption

AIMS

Alcohol consumption is known to be associated with risky sexual behaviours, but this relationship may be complex and bidirectional. We explored whether alcohol consumption leads to the consumer being rated as more attractive than sober individuals.

METHODS

Heterosexual social alcohol consumers completed an attractiveness-rating task, in which they were presented with pairs of photographs depicting the same individual, photographed while sober and after having consumed alcohol (either 0.4 or 0.8 g/kg), and required to decide which image was more attractive.

RESULTS

Photographs of individuals who had consumed a low dose of alcohol (equivalent to 250 ml of wine at 14% alcohol by volume for a 70 kg individual) were rated as more attractive than photographs of sober individuals. This was not observed for photographs of individuals who had consumed a high dose of alcohol.

CONCLUSION

In addition to perceiving others as more attractive, a mildly intoxicated alcohol consumer may also be perceived as more attractive by others. This in turn may play a role in the relationship between alcohol consumption and risky sexual behaviour.

Melanoma risk after ovarian stimulation for in vitro fertilization

STUDY QUESTION

Do women treated with ovarian stimulation for IVF have an increased risk of melanoma?

SUMMARY ANSWER

Ovarian stimulation for IVF does not increase risk of melanoma, even after a prolonged follow-up.

WHAT IS KNOWN ALREADY

Although exposure to ultraviolet radiation is the major risk factor for melanoma, associations between female sex steroids and melanoma risk have also been suggested. The results of available studies on fertility drugs and melanoma risk are inconclusive since most studies had several methodological limitations such as short follow-up, a small number of cases and no subfertile comparison group.

STUDY DESIGN, SIZE, DURATION

In 1996, a nationwide historic cohort study (the OMEGA-cohort) was established to examine the risk of cancer after ovarian stimulation for IVF. After a median follow-up of 17 years, cancer incidence was ascertained through linkage with the Netherlands Cancer Registry. Melanoma risk in the cohort was compared with that in the general population and between the IVF group and non-IVF group using multivariable Cox regression analyses.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The cohort comprises 19 158 women who received IVF between 1983 and 1995 and a comparison group of 5950 women who underwent subfertility treatments other than IVF. Detailed IVF-treatment data were obtained from the medical records and complete information on parity and age at first birth was obtained through linkage with the Dutch Municipal Personal Records Database.

MAIN RESULTS AND THE ROLE OF CHANCE

In total, 93 melanoma cases were observed. The risk of melanoma was not elevated among IVF-treated women, neither when compared with the general population (standardized incidence ratio = 0.89; 95% confidence interval (CI): 0.69-1.12), nor when compared with the non-IVF group (adjusted hazard ratio (HR) = 1.27; 95% CI: 0.75-2.15). A higher number of IVF cycles was associated with apparent but statistically non-significant risk increases (5-6 cycles HR = 1.92; ≥7 cycles HR = 1.79). However, no significant trend emerged. In women with more follicle stimulating hormone/human menopausal gonadotrophin ampoules comparable non-significant risk increases were found. A longer follow-up did not increase melanoma risk. Nulliparous women did not have a significantly higher melanoma risk than parous women (HR = 1.22; 95% CI: 0.81-1.84). However, women who were 30 years of age or older at first birth had a significantly higher melanoma risk than women who were younger than 30 years at first birth (age: 30-34 years HR = 4.57; 95% CI: 2.07-10.08, >34 years HR = 2.98; 95% CI: 1.23-7.21).

LIMITATIONS, REASONS FOR CAUTION

Despite our large cohort, the number of melanoma cases was rather small, especially in our comparison group, which hampered subgroup analyses.

WIDER IMPLICATIONS OF THE FINDINGS

Our results are reassuring for women who underwent IVF or are contemplating to start IVF. Since our cohort study is one of the largest published so far, with long-term follow-up, a subfertile comparison group, and detailed IVF-treatment data, our results add important information to the available evidence.

STUDY FUNDING/COMPETING INTEREST

This study was supported by grants from the Dutch Cancer Society (NKI 2006-3631), the Health Research and Development Counsel (28-2540) and the Dutch Ministry of Health.

Differential responses to steroid hormones in fibroblasts from the vocal fold, trachea, and esophagus

There is accumulating evidence that fibroblasts are target cells for steroids such as sex hormones and corticoids. The characteristics of fibroblasts vary among tissues and organs. Our aim in this study is to examine differences in responses to steroid hormones among fibroblasts from different cervicothoracic regions. We compared the actions of steroid hormones on cultured fibroblasts from the vocal folds, which are considered to be the primary target of steroid hormones, and the trachea and esophagus in adult male rats. Expression of steroid hormone receptors (androgen receptor, estrogen receptor α, and glucocorticoid receptor) was identified by immunofluorescence histochemistry. Androgen receptor was much more frequently expressed in fibroblasts from the vocal fold than in those from the trachea and esophagus. Cell proliferation analysis showed that administration of testosterone, estradiol, or corticosterone suppressed growth of all 3 types of fibroblasts. However, mRNA expression for extracellular matrix-associated genes, including procollagen I and III and elastin, and hyaluronic acid synthase I was elevated only by addition of testosterone to fibroblasts from the vocal fold. These results indicate that each steroid hormone exerts region-specific effects on cervicothoracic fibroblasts with different properties through binding to specific receptors.

Cutaneous Melanoma in Women

Background

Gender disparity in melanoma outcome is consistently observed, suggesting that gender is as an important prognostic factor. However, the source of this gender disparity in melanoma remains unclear.

Objective

This article reviews advances in our understanding of gender differences in melanoma and how such differences may contribute to outcomes.

Methods

A broad literature search was conducted using the PubMed database, with search terms such as ‘gender differences in melanoma’ and ‘sex differences in melanoma.’ Additional articles were identified from cited references.

Results

Herein, we address the gender-linked physiologic differences in skin and melanoma. We discuss the influence of estrogen on a woman’s risk for melanoma and melanoma outcomes with regard to pregnancy, oral contraceptives, hormone replacement therapy, and UV tanning.

Conclusions

The published findings on gender disparities in melanoma have yielded many advances in our understanding of this disease. Biological, environmental, and behavioral factors may explain the observed gender difference in melanoma incidence and outcome. Further research will enable us to learn more about melanoma pathogenesis, with the goal of offering better treatments and preventative advice to our patients.

Pre-clinical evaluation of soybean-based wound dressings and dermal substitute formulations in pig healing and non-healing in vivo models

In the last decade, a new class of natural biomaterials derived from de-fatted soybean flour processed by either thermoset or extraction procedures has been developed. These biomaterials uniquely combine adaptability to various clinical applications to proven tissue regeneration properties. In the present work, the biomaterials were formulated either as hydrogel or as paste formulation and their potential as wound dressing material or as dermal substitute was assessed by two in vivo models in pig skin: The healing full-thickness punch biopsy model and the non-healing full-thickness polytetrafluoroethylene (PTFE) chamber model. The results clearly show that collagen deposition is induced by the presence of these biomaterials. A unique pattern of early inflammatory response, eliciting neutrophils and controlling macrophage infiltration, is followed by tissue cell colonization of the wound bed with a significant deposition of collagen fibers. The study also highlighted the importance in the use of optimal formulations and appropriate handling upon implantation. In large size, non-healing wounds, wound dermis was best obtained with the paste formulation as hydrogels appeared to be too loose to ensure lasting scaffolding properties. On the contrary, packing of the granules during the application of paste reduced biomaterial degradation rate and prevent the penetration of newly vascularized tissue, thus impeding grafting of split-thickness autologous skin grafts on the dermal substitute base.

Estrogens and aging skin

Estrogen deficiency following menopause results in atrophic skin changes and acceleration of skin aging. Estrogens significantly modulate skin physiology, targeting keratinocytes, fibroblasts, melanocytes, hair follicles and sebaceous glands, and improve angiogenesis, wound healing and immune responses. Estrogen insufficiency decreases defense against oxidative stress; skin becomes thinner with less collagen, decreased elasticity, increased wrinkling, increased dryness and reduced vascularity. Its protective function becomes compromised and aging is associated with impaired wound healing, hair loss, pigmentary changes and skin cancer.

 

Skin aging can be significantly delayed by the administration of estrogen. This paper reviews estrogen effects on human skin and the mechanisms by which estrogens can alleviate the changes due to aging. The relevance of estrogen replacement, selective estrogen receptor modulators (SERMs) and phytoestrogens as therapies for diminishing skin aging is highlighted. Understanding estrogen signaling in skin will provide a basis for interventions in aging pathologies.

RNASEL and MIR146A SNP-SNP interaction as a susceptibility factor for non-melanoma skin cancer

Immunity and inflammatory pathways are important in the genesis of non-melanoma skin cancers (NMSC). Functional genetic variation in immune modulators has the potential to affect disease etiology. We investigated associations between common variants in two key regulators, MIR146A and RNASEL, and their relation to NMSCs. Using a large population-based case-control study of basal cell (BCC) and squamous cell carcinoma (SCC), we investigated the impact of MIR146A SNP rs2910164 on cancer risk, and interaction with a SNP in one of its putative targets (RNASEL, rs486907). To examine associations between genotype and BCC and SCC, occurrence odds ratios (OR) and 95% confidence intervals (95%CI) were calculated using unconditional logistic regression, accounting for multiple confounding factors. We did not observe an overall change in the odds ratios for SCC or BCC among individuals carrying either of the RNASEL or MIR146A variants compared with those who were wild type at these loci. However, there was a sex-specific association between BCC and MIR146A in women (ORGC = 0.73, [95%CI = 0.52-1.03]; ORCC = 0.29, [95% CI = 0.14-0.61], p-trend<0.001), and a reduction in risk, albeit not statistically significant, associated with RNASEL and SCC in men (ORAG = 0.88, [95%CI = 0.65-1.19]; ORAA = 0.68, [95%CI = 0.43-1.08], p-trend = 0.10). Most striking was the strong interaction between the two genes. Among individuals carrying variant alleles of both rs2910164 and rs486907, we observed inverse relationships with SCC (ORSCC = 0.56, [95%CI = 0.38-0.81], p-interaction = 0.012) and BCC (ORBCC = 0.57, [95%CI = 0.40-0.80], p-interaction = 0.005). Our results suggest that genetic variation in immune and inflammatory regulators may influence susceptibility to NMSC, and novel SNP-SNP interaction for a microRNA and its target. These data suggest that RNASEL, an enzyme involved in RNA turnover, is controlled by miR-146a and may be important in NMSC etiology.

A hair growth-promoting effect of Chinese black tea extract in mice

Chinese black tea extract (CBTE) fermented with Aspergillus sp. significantly promoted hair growth after 2 weeks of topical application in shaved 6 week-old male C3H/He mice. The hair growth-promoting effect of CBTE was potentiated synergistically by capsaicin, which has no effect on hair growth by itself. CBTE displayed an affinity for estrogen receptor (ER)α, with an IC50 value of 74.8 µg/mL. This effect of CBTE might be mediated by the ERs, since a similar effect induced by orally administered soy isoflavone, a mixture of ERs ligands, has been reported to be synergistically potentiated by capsaicin.

The use of a whole animal biophotonic model as a screen for the angiogenic potential of estrogenic compounds

BACKGROUND

Vascular endothelial growth factor (VEGF) is essential for normal vascular growth and development during wound repair. VEGF is estrogen responsive and capable of regulating its own receptor, vascular endothelial growth factor receptor-2 (VEGFR-2). Several agricultural pesticides (e.g., methoxychlor) have estrogenic potential that can initiate inappropriate physiological responses in estrogenic-sensitive tissues following exposure in vivo. Thus, the current study was designed to determine whether the VEGFR-2-Luciferase (Luc) reporter transgenic mouse is a useful model for evaluating estrogenic tendencies of methoxychlor by monitoring wound healing via VEGFR-2-mediated gene expression using bioluminescence and real-time imaging technology.

RESULTS

VEGFR-2-Luc gene activity peaked by d 7 (P<0.001) in all groups but was not different (P>0.05) between control and estrogen/methoxychlor exposed mice.

CONCLUSIONS

Changes in VEGFR-2-Luc gene activity associated with the dermal wound healing process were able to be measured via photonic emission. The increase in vasculature recruitment and formation is paralleled by the increase of VEGFR-2-Luc activity with a peak on day 7. However, estrogen/methoxychlor did not significantly alter wound healing mediated VEGFR-2-Luc gene expression patterns compared to controls. This suggests that the VEGFR-2-Luc transgenic mouse wound model tested in this study may not be optimal for use as a screen for the angiogenic potential of estrogenic compounds.

Symbiotic bacteria appear to mediate hyena social odors

All animals harbor beneficial microbes. One way these microbes can benefit their animal hosts is by increasing the diversity and efficacy of communication signals available to the hosts. The fermentation hypothesis for mammalian chemical communication posits that bacteria in the scent glands of mammals generate odorous metabolites used by their hosts for communication and that variation in host chemical signals is a product of underlying variation in the bacterial communities inhabiting the scent glands. An effective test of this hypothesis would require accurate surveys of the bacterial communities in mammals' scent glands and complementary data on the odorant profiles of scent secretions--both of which have been historically lacking. Here we use next-generation sequencing to survey deeply the bacterial communities in the scent glands of wild spotted and striped hyenas. We show that these communities are dominated by fermentative bacteria and that the structures of these communities covary with the volatile fatty acid profiles of scent secretions in both hyena species. The bacterial and volatile fatty acid profiles of secretions differ between spotted and striped hyenas, and both profiles vary with sex and reproductive state among spotted hyenas within a single social group. Our results strongly support the fermentation hypothesis for chemical communication, suggesting that symbiotic bacteria underlie species-specific odors in both spotted and striped hyenas and further underlie sex and reproductive state-specific odors among spotted hyenas. We anticipate that the fermentation hypothesis for chemical communication will prove broadly applicable among scent-marking mammals as others use the technical and analytical approaches used here.

Female pattern hair loss

CONTEXT

Female pattern hair loss (FPHL) also known as female androgenetic alopecia is a common condition afflicting millions of women that can be cosmetically disrupting. Prompt diagnosis and treatment are essential for obtaining optimal outcome. This review addresses the clinical presentation of female pattern hair loss, its differential diagnosis and treatment modalities.

EVIDENCE ACQUISITION

A) Diffuse thinning of the crown region with preservation of the frontal hairline (Ludwig's type) B) The "Christmas tree pattern" where the thinning is wider in the frontal scalp giving the alopecic area a triangular shaped figure resembling a christmas tree. C) Thinning associated with bitemporal recession (Hamilton type). Generally, FPHL is not associated with elevated androgens. Less commonly females with FPHL may have other skin or general signs of hyperandrogenism such as hirsutism, acne, irregular menses, infertility, galactorrhea and insulin resistance. The most common endocrinological abnormality associated with FPHL is polycystic ovarian syndrome (PCOS).

RESULTS

The most important diseases to consider in the differential diagnosis of FPHL include Chronic Telogen Effluvium (CTE), Permanent Alopecia after Chemotherapy (PAC), Alopecia Areata Incognito (AAI) and Frontal Fibrosing Alopecia (FFA). This review describes criteria for distinguishing these conditions from FPHL.

CONCLUSIONS

The only approved treatment for FPHL, which is 2% topical Minoxidil, should be applied at the dosage of 1ml twice day for a minimum period of 12 months. This review will discuss off-label alternative modalities of treatment including 5-alfa reductase inhibitors, antiandrogens, estrogens, prostaglandin analogs, lasers, light treatments and hair transplantation.

Intractable diffuse alopecia caused by multifactorial side-effects in treatment of acute lymphocytic leukemia: connection to iatrogenic failure of estrogen secretion

Treatment of infantile acute lymphocytic leukemia (ALL) may cause failure to thrive and hypogonadism due to hypopituitarism induced by chemotherapy and whole-brain radiotherapy. We report the case of a 22-year-old girl with a genetic predisposition to pattern hair loss who developed inveterate diffuse alopecia. The patient had onset of ALL at 8 years old and underwent bone marrow transplantation (BMT). Diffuse alopecia gradually advanced over her whole body. Her vellus scalp hair gradually came out, and hair loss progressed again at 8 years, after BMT. She later developed iatrogenic failure of secretion of estrogen and was treated with estrogen substitution therapy for 14 months from the age of 20. There was a small increase in the volume of hair during therapy, but alopecia returned to the former level after the therapy was suspended. Histopathologic examinations of the scalp performed during estrogen substitution therapy and 2 years after suspension of the therapy showed a 60% decrease in the number of hair follicles and prominent development of vellus hair. We conclude that estrogen influenced hair growth in the context of a genetic predisposition for pattern hair loss in this case.

Colour Detection Thresholds in Faces and Colour Patches

Human facial skin colour reflects individuals' underlying health (Stephen et al 2011 Evolution & Human Behavior32 216–227); and enhanced facial skin CIELab b* (yellowness), a* (redness), and L* (lightness) are perceived as healthy (also Stephen et al 2009a International Journal of Primatology30 845–857). Here, we examine Malaysian Chinese participants' detection thresholds for CIELab L* (lightness), a* (redness), and b* (yellowness) colour changes in Asian, African, and Caucasian faces and skin coloured patches. Twelve face photos and three skin coloured patches were transformed to produce four pairs of images of each individual face and colour patch with different amounts of red, yellow, or lightness, from very subtle (Δ E = 1.2) to quite large differences (Δ E = 9.6). Participants were asked to decide which of sequentially displayed, paired same-face images or colour patches were lighter, redder, or yellower. Changes in facial redness, followed by changes in yellowness, were more easily discriminated than changes in luminance. However, visual sensitivity was not greater for redness and yellowness in nonface stimuli, suggesting red facial skin colour special salience. Participants were also significantly better at recognizing colour differences in own-race (Asian) and Caucasian faces than in African faces, suggesting the existence of cross-race effect in discriminating facial colours. Humans' colour vision may have been selected for skin colour signalling (Changizi et al 2006 Biology Letters2 217–221), enabling individuals to perceive subtle changes in skin colour, reflecting health and emotional status.

Natural expansion of artificial dermal template by successful full-term pregnancy

Extensive postburn scars of the trunk may cause breathing difficulty and, in female patients of reproductive age, render future pregnancy a serious reconstructive goal. Scar excision and skin grafting with or without artificial dermal templates is the current preferred management. A patient who underwent staged extensive grafting of the abdominal wall by dermal regeneration template and completed a full-term successful pregnancy is presented here. Although tissue expanders have been used to expand artificial dermal templates, natural expansion by pregnancy has not been previously documented. A 30-year-old woman with extensive chest and abdominal wall, bilateral gluteal and breast scars after burns sustained at childhood presented with difficulty in deep breathing. Abdominal scar tissue was excised and the abdominal wall was reconstructed by dermal regeneration template and autologous thin split-thickness skin graft in two stages. Six months postoperatively, spirometric values were improved by 15%, while 1 year later the patient completed successfully a full-term pregnancy. Reconstruction of extensive abdominal postburn scars by dermal regeneration template improves breathing by increasing elasticity and compliance of the reconstructed area. In female patients, the template can be extensively and naturally expanded by the gradually growing uterus, allowing for full-term pregnancy.

A role for estrogen receptor-α and estrogen receptor-β in collagen biosynthesis in mouse skin

Hormonal regulation of the dermal collagenous extracellular matrix plays a key role in maintaining proper tissue homeostasis, however the factors and pathways involved in this process are not fully defined. This study investigated the role of estrogen receptors (ERs) in the regulation of collagen biosynthesis in mice lacking ERα or ERβ. Collagen content was significantly increased in the skin of ΕRα^-/- mice as measured by acetic acid extraction and the hydroxyproline assay and correlated with the decreased levels of MMP-15 and elevated collagen production by ΕRα^-/- fibroblasts. In contrast, collagen content was decreased in the skin of ERβ^-/- mice despite markedly increased collagen production by ERβ^-/- fibroblasts. However, expression of several matrix metalloproteinases (MMPs), including MMP-8 and -15 was significantly elevated suggesting increased degradation of dermal collagen. Furthermore, ERβ^-/- mice were characterized by significantly reduced levels of small leucine proteoglycans (SLRPs), lumican and decorin, leading to the defects in collagen fibrillogenesis and possibly less stable collagen fibrils. ERα^-/- mice also exhibited fibrils with irregular structure and size, which correlated with increased levels of lumican and decorin. Together, these results demonstrate distinct functions of estrogen receptors in the regulation of collagen biosynthesis in mouse skin in vivo.

Expression of estrogen receptor alpha and beta is decreased in hypospadias

PURPOSE

Estrogenic endocrine disruptors acting via estrogen receptors α and β have been implicated in the etiology of hypospadias. However, the expression and distribution of estrogen receptors α and β in normal and hypospadiac human foreskins is unknown. We characterized the location and expression of estrogen receptors α and β in normal and hypospadiac foreskins.

MATERIALS AND METHODS

We prospectively collected excess foreskin from 35 patients undergoing hypospadias repair and 15 patients undergoing elective circumcision. Hypospadias was classified as severe in 18 patients and mild in 17 based on the ectopic position of the meatus. mRNA expression levels in estrogen receptors α and β were quantified using reverse transcriptase polymerase chain reaction. Receptor location was characterized by immunohistochemical analysis. Additionally immunohistochemical analysis was performed in 4 archived human fetal penises.

RESULTS

Mean ± SD ages were similar for the circumcision (9.5±3 months) and hypospadias repair groups (9±3 months, p=0.75). mRNA expression levels in estrogen receptors α and β were significantly decreased in hypospadiac foreskin cases compared to controls (p<0.001), while no statistically significant differences were seen between foreskins with severe and mild hypospadias. Estrogen receptor β immunostaining was strong in normal foreskin but weak in hypospadiac foreskin. Estrogen receptor β immunoreactivity was most intense in the stratum basale and stratum spinosum. Estrogen receptor α immunostaining was weak in normal and mild hypospadias foreskin, and undetectable in severe hypospadias. Fetal penises expressed strong estrogen receptor β immunopositivity in the urethral plate epithelium, corpus spongiosum, corpora cavernosa and penile skin, while estrogen receptor α immunostaining was not detected.

CONCLUSIONS

These data demonstrate a difference in estrogen receptor α and β expression and location in the foreskin of patients with hypospadias compared to controls. These findings are consistent with aberrant estrogenic effects having a role in the etiology of hypospadias.

Tissue-Specific Effects of Loss of Estrogen during Menopause and Aging

The roles of estrogens have been best studied in the breast, breast cancers, and in the female reproductive tract. However, estrogens have important functions in almost every tissue in the body. Recent clinical trials such as the Women's Health Initiative have highlighted both the importance of estrogens and how little we know about the molecular mechanism of estrogens in these other tissues. In this review, we illustrate the diverse functions of estrogens in the bone, adipose tissue, skin, hair, brain, skeletal muscle and cardiovascular system, and how the loss of estrogens during aging affects these tissues. Early transcriptional targets of estrogen are reviewed in each tissue. We also describe the tissue-specific effects of selective estrogen receptor modulators (SERMs) used for the treatment of breast cancers and postmenopausal symptoms.

Does hormone replacement therapy and use of oral contraceptives increase the risk of non-melanoma skin cancer?

OBJECTIVE

We aimed to examine whether use of hormone replacement therapy (HRT) and oral contraceptives (OC) affect the risk of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) in women.

METHODS

Using data from 29,875 women enrolled in the prospective "Diet, Cancer, and Health" study between 1993 and 1997, women with available information on HRT and OC use at baseline were identified. Statistical analyses were based on the Cox's proportional hazards model.

RESULTS

The mean age at enrollment in the study was 56.7 years, whereas the mean age at the end of follow-up was 67.5 years. 1,175 cases of BCC and 76 cases of SCC were identified in the cohort during follow-up through 2007. The BCC incidence rate ratio was 1.15 (95% CI: 1.07-1.37) for ever users of HRT at baseline compared to never users, whereas risk of BCC was unaffected by duration of HRT use. Ever use of HRT was not associated with SCC risk but a significantly increased risk of 1.35 (95% CI: 1.05-1.72) associated with every 5 years of HRT use was observed. No convincing associations between OC use and BCC or SCC risk were observed.

CONCLUSION

The findings indicated that HRT but not OC may increase the risk of NMSC. However, further studies are warranted as risk estimates for SCC had relatively low precision due to a limited number of SCC cases.

Does a Woman’s Skin Color Indicate Her Fertility Level?

Roberts et al. (2004 ) showed that perceived facial attractiveness of women is higher in the fertile phase of the menstrual cycle than in the luteal phase, suggesting the existence of visible cues of ovulation. However, the nature of such cues remains speculative. Here, in an initial pilot study, we test the hypothesis that changes in female facial skin coloration across the menstrual cycle could be one of the signals that men have adapted to in order to assess female fertility. Spectrophotometric measurements of the facial skin color of normally ovulating Caucasian women (aged 24–29 years) were collected in the late follicular and midluteal phase of their menstrual cycle. Facial images were also taken in both sessions and judged for attractiveness and health by a panel of German men (aged 16–37 years). In line with Roberts et al. (2004 ), our results show that men perceive women in the late follicular phase to be significantly more attractive and healthier than those in the midluteal phase. However, we did not detect any significant differences in objective measurements of skin color between the two phases. We conclude that the increase in male perception of female facial attractiveness and health in the fertile phase of the menstrual cycle is not caused by a change in overall skin color and/or lightness.

Diethylstilbestrol enhances melanogenesis via cAMP-PKA-mediating up-regulation of tyrosinase and MITF in mouse B16 melanoma cells

BACKGROUND

It is well known that melanin synthesis in melanoma cells is controlled by melanogenic enzymes, which regulate the cAMP-PKA signaling pathway. Estrogen was previously reported to upregulate melanogenesis that is associated with human skin pigmentation.

OBJECTIVE

To investigate the influence and mechanism of diethylstilbestrol (DES) on melanogenesis in mouse B16 melanoma cells.

METHODS

The effects of diethylstilbestrol on cell viability, melanin content, tyrosinase activity, cAMP level, expression of the tyrosinase family and microphthalmia related transcription factor (MITF) were measured in B16 melanoma. Estrogen receptor (ER) expression were detected in B16 melanoma and A375 melanoma. Diethylstilbestrol-induced melanin synthesis were evaluated in the presence and absence of H89 (a PKA-specific inhibitor) and ICI182, 780 (a pure ER antagonist). Tyrosinase activity, the mRNA levels of tyrosinase and MITF were evaluated in the presence and absence of H89.

RESULTS

In B16 cells, diethylstilbestrol increased cell proliferation, melanin synthesis, tyrosinase activity and expression of the tyrosinase family and MITF. ER expression have not difference in human and mouse melanoma. When ER were inhibited by ICI182, 780, DES-induced melanogenesis was significantly reduced. Diethylstilbestrol enhanced the level of cAMP. The upregulation of melanin content and tyrosinase activity stimulated by diethylstilbestrol was significantly attenuated in the presence of H89. Further, diethylstilbestrol-induced upregulation of tyrosinase and MITF were significantly attenuated when the PKA pathway was blocked.

CONCLUSIONS

Diethylstilbestrol can enhance melanin synthesis in melanoma cells. This effect is associated with activation of the cAMP-PKA pathway and upregulation of expression and activity of the melanogenesis-related enzyme tyrosinase and MITF.