The skin aging exposome

Fighting against Skin Aging: The Way from Bench to Bedside

As the most voluminous organ of the body that is exposed to the outer environment, the skin suffers from both intrinsic and extrinsic aging factors. Skin aging is characterized by features such as wrinkling, loss of elasticity, laxity, and rough-textured appearance. This aging process is accompanied with phenotypic changes in cutaneous cells as well as structural and functional changes in extracellular matrix components such as collagens and elastin. In this review, we summarize these changes in skin aging, research advances of the molecular mechanisms leading to these changes, and the treatment strategies aimed at preventing or reversing skin aging.

Personalized skincare: from molecular basis to clinical and commercial applications

Individual responses of human skin to the environmental stress are determined by differences in the anatomy and physiology that are closely linked to the genetic characteristics such as pigmentation. Ethnic skin phenotypes can be distinguished based on defined genotypic traits, structural organization and compartmentalized sensitivity to distinct extrinsic aging factors. These differences are not only responsible for the variation in skin performance after exposure to damaging conditions, but can also affect the mechanisms of drug absorption, sensitization and other longer term effects. The unique characteristics of the individual skin function and, particularly, of the ethnic skin type are currently considered to shape the future of clinical and pharmacologic interventions as a basis for personalized skincare. Individual approaches to skincare render a novel and actively growing area with a range of biomedical and commercial applications within cosmetics industry. In this review, we summarize the aspects of the molecular and clinical manifestations of the environmental stress on human skin and proposed protective mechanisms that are linked to ethnic differences and pathophysiology of extrinsic skin aging. We subsequently discuss the possible applications and translation of this knowledge into personalized skincare.

Protective effects of an extract of the freshwater microalga Scenedesmus rubescens on UV-irradiated skin cells

BACKGROUND

Skin ageing results from intrinsic but also extrinsic factors of which UV irradiation is a main cause. It is hence of interest to have means to protect skin from UV irradiation-induced damage. We selected an extract of the freshwater microalga Scenedesmus rubescens and assessed its potential to protect skin from photoageing caused by UV irradiation.

METHODS

Skin cells in vitro and ex vivo were analysed for markers of UV irradiation-induced photodamage such as decreased viability, decreased collagen content, hyperpigmentation and sunburn cells.

RESULTS

We found that a dry extract of the microalga Scenedesmus rubescens was able to suppress cellular signs of ageing induced by UV irradiation. It enhanced dermal fibroblast viability, rescued dermal collagen content, inhibited the formation of sunburn cells and inhibited tyrosinase activity.

CONCLUSION

An extract of Scenedesmus rubescens showed broad activity against markers of UV irradiation-induced cutaneous ageing. It may therefore be used as a preventive or regenerative agent for anti-ageing strategies.

The influence of exposome on acne

BACKGROUND

Acne vulgaris is one of the main reasons for dermatological consultations. Severity and response to treatment may be impacted by various external factors or exposome.

AIM

To assess the impact of environmental factors on acne and to provide a comprehensive overview of the acne exposome.

METHODS

Two consensus meetings of five European dermatologists and a comprehensive literature search on exposome factors triggering acne served as a basis for this review.

RESULTS

Acne exposome was defined as the sum of all environmental factors influencing the occurrence, duration and severity of acne. Exposome factors impact on the response and the frequency of relapse to treatments by interacting with the skin barrier, sebaceous gland, innate immunity and cutaneous microbiota. They may be classified into the following six main categories: nutrition, psychological and lifestyle factors, occupational factors including cosmetics, as well as pollutants, medication and climatic factors. Moreover, practical considerations for the dermatologist's clinical practice are proposed.

CONCLUSION

Exposome factors including nutrition, medication, occupational factors, pollutants, climatic factors, and psychosocial and lifestyle factors may impact on the course and severity of acne and on treatment efficacy. Identifying and reducing the impact of exposome is important for an adequate acne disease management.

GSK126 (EZH2 inhibitor) interferes with ultraviolet A radiation-induced photoaging of human skin fibroblast cells

Polycomb group genes (PcG) encode chromatin modification proteins that are involved in the epigenetic regulation of cell differentiation, proliferation and the aging processes. The key subunit of the PcG complex, enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2), has a central role in a variety of mechanisms, such as the formation of chromatin structure, gene expression regulation and DNA damage. In the present study, ultraviolet A (UVA) was used to radiate human dermal fibroblasts in order to construct a photo-aged cell model. Subsequently, the cell viability assay, Hoechst staining, apoptosis detection using flow cytometry, senescence-associated β-galactosidase (SA-β-gal) staining and erythrocyte exclusion experiments were performed. GSK126, a histone methylation enzyme inhibitor of EZH2, was used as an experimental factor. Results suggested that GSK126 downregulated the mRNA expression levels of EZH2 and upregulated the mRNA expression levels of BMI-1. Notably, GSK126 affected the transcription of various photoaging-related genes and thus protected against photoaging induced by UVA radiation.

Dietary intake of glucono-δ-lactone attenuates skin inflammation and contributes to maintaining skin condition

Skin properties are influenced by both external (e.g., ultraviolet [UV], chemicals, and bacteria) and internal factors (e.g., nutrition and hormones). Therefore, some dietary supplements are expected to improve skin conditions. Glucono-δ-lactone (GDL) is widely used as a food additive and is naturally present in wine, honey, and other foods. The aim of this study was to assess whether GDL improves skin condition and inflammation. In a double-blind, placebo-controlled study, 40 healthy Japanese male volunteers were randomly assigned to either the GDL (2000 mg day^-1) or placebo group. A significant difference was found in the rates of change in transepidermal water loss (TEWL) from the baseline to 6 months between the placebo and GDL groups (P < 0.05). Facial lightness (L*) significantly increased by 1.6% only in the GDL group at 6 months compared with the baseline. The value of the elasticity parameter, Ua/Uf, of dietary GDL significantly increased (6.2% at 2 months and 5.4% at 6 months). Besides these, dietary GDL suppressed UVB-induced erythema (a*) and pigmentation (L*). Dietary GDL has anti-inflammatory effects on the skin and prevents/improves skin disorders caused by seasonal change.

“Less Blue, More Clean”: Cu2O nano-cubic functionalized hydrogel for the energy transformation of light-emitting screens

Cubic Cu₂O nanoparticle modified hydrogel (CMHG) was synthesized to address two major problems (harmful irradiation and high density pathogens) of the current light-emitting screens simultaneously. The as-prepared hydrogel could conveniently form an adjustable semitransparent film over various shaped screens to provide enhanced antibacterial activity and longer Cu₂O service life. More importantly, with the aid of cubic Cu₂O nanoparticles, the energy of the harmful blue light irradiation could be effectively transformed into a photocatalysed power source to sterilize the surface of the screen. This low toxic CMHG showed no significant influence on the touch control experience, and had obvious eye protective effects, which thus offered a convenient manner to protect vision and sterilize touch screens at the same time.

Through coverage, blue light irradiation could be absorbed and transformed into photocatalysed power to sterilize the surface.

High Sensitivity of Human Adipose Stem Cells to Differentiate into Myofibroblasts in the Presence of C. aspersa Egg Extract

Introduction

Regeneration therapy using adipose-derived stem cells (ADSC) has been proposed in the treatment of skin aging. Myofibroblast plays a relevant role in the organization of the extracellular matrix of the damaged skin. A natural extract was derived from the eggs of the mollusk Cryptomphalus aspersa (e-CAF) that seems to play a role on skin repair. We have investigated the potential effects of e-CAF in the differentiation of ADSC.

Materials and methods

ADSC were cultured in the absence or presence of e-CAF (50 and 200 μg/mL) for 24 hours and 7 days. Real-time cell assay, morphological, immunofluorescence, and RT-PCR techniques were used to evaluate the cell culture and expression of αSMA, collagen I, and tropoelastin.

Results

e-CAF induced significant reduction in the rate of growth of ADSC from 24 hours to 7 days of culture. e-CAF also induced bigger sizes, higher levels of cytoplasmic refringence and complexity, and a more polyhedral morphological changes in the cultured ADSC. The protein and mRNA expression of αSMA was significantly increased in e-CAF-cultured ADSC.

Conclusion

e-CAF promotes ADSC differentiation to myofibroblasts and should be considered as a potential agent for the prevention and treatment of skin aging.

What is the role of mitochondrial dysfunction in skin photoaging?

Skin ageing is a complex process involving both internal and external factors, which leads to a progressive loss of cutaneous function and structure. Solar radiation is the primary environmental factor implicated in the development of skin ageing, and the term photoaging describes the distinct clinical, histological and structural features of chronically sun-exposed skin. The changes that accompany photoaging are undesirable for aesthetic reasons and can compromise the skin and make it more susceptible to a number of dermatological disorders. As a result, skin ageing is a topic that is of growing interest and concern to the general population, illustrated by the increased demand for effective interventions that can prevent or ameliorate the clinical changes associated with aged skin. In this viewpoint essay, we explore the role that mitochondria play in the process of skin photoaging. There is continuing evidence supporting the proposal that mitochondrial dysfunction and oxidative stress are important contributing factors in the development of skin photoaging. Further skin-directed mitochondrial research is warranted to fully understand the impact of mitochondrial status and function in skin health. A greater understanding of the ageing process and the regulatory mechanisms involved could lead to the development of novel preventative interventions for skin ageing.

A smoking prevention photoageing intervention for secondary schools in Brazil delivered by medical students: protocol for a randomised trial

INTRODUCTION

Most smokers start smoking during their early adolescence, often with the idea that smoking is glamorous; the dramatic health consequences are too far in the future to fathom. We recently designed and tested an intervention that takes advantage of the broad availability of mobile phones as well as adolescents' interest in their appearance. A free photoageing mobile app (Smokerface) was implemented by medical students in secondary schools via a novel method called mirroring. The pupils' altered three-dimensional selfies on tablets were 'mirrored' via a projector in front of their whole grade. This is the first randomised trial to measure the effectiveness of the mirroring approach on smoking behaviour in secondary schools.

METHODS AND ANALYSIS

The mirroring intervention, which lasts 45 min, is implemented by Brazilian medical students in at least 35 secondary school classes with 21 participants each (at least 35 classes with 21 participants for control) in February 2018 in the city of Itauna, Brazil. External block randomisation via computer is performed on the class level with a 1:1 allocation. In addition to sociodemographic data, smoking behaviour is measured via a paper-pencil questionnaire before, 3 and 6 months postintervention plus a random carbon monoxide breathing test at baseline and end line. The primary outcome is cigarette smoking in the past week at 6 months follow-up. Smoking behaviour (smoking onset, quitting) and effects on the different genders are studied as secondary outcomes. Analysis is by intention to treat.

ETHICS AND DISSEMINATION

Ethical approval is obtained from the ethics committee of the University of Itauna in Brazil. Results will be disseminated at conferences, in peer-reviewed journals, throughout the Education Against Tobacco network social media channels and on our websites.

TRIAL REGISTRATION NUMBER

NCT03178227.

Skin aging parameters: A window to heart block

BACKGROUND

Skin acts as a mirror to the internal state of the body.

HYPOTHESIS

We tried to find the relation between skin aging parameters and the incidence of degenerative AV block.

METHODS

This study included 97 patients divided into 2 groups; group D comprised 49 patients with advanced-degree AV block, and group C comprised the 48 matched control group. All were subjected to full history taking, thorough clinical examination, calculation of intrinsic skin aging score, and resting 12-lead surface electrocardiography (ECG). ECG for all patients assessed left ventricular end-systolic diameter, left ventricular end-diastolic diameter, ejection fraction, left atrium (LA) diameter, aortic root diameter, mitral annular calcification, aortic sclerosis. Coronary angiography was also performed when indicated for patients in group D.

RESULTS

Patients in group D had a higher percentages of uneven pigmentation, fine skin wrinkles, lax appearance, seborrheic keratosis, total score > 7 (38 [77.55%] vs 10 [20.83%]), mitral annular calcification score of 33 (67.34%) vs 5 (10.41%), aortic sclerosis score of 21 (42.85%) vs 4 (8.33%), and mean LA diameter of 39.98 ± 5.52 vs 36.21 ± 3 mm (P < 0.001). Total score > 6 is the best cutoff value to predict advanced-degree heart block with 89.79% sensitivity and 64.58% specificity. Seborrheic keratosis was the strongest independent predictor.

CONCLUSIONS

Any population with a total intrinsic skin aging score of >6 is at high risk for developing advanced-degree AV block and should undergo periodic ECG follow-up for early detection of any conduction disturbance in the early asymptomatic stages to minimize sudden cardiac death.

Towards topical microRNA-directed therapy for epidermal disorders

There remains an unmet dermatological need for innovative topical agents that achieve better longterm outcomes with fewer side effects. Modulation of the expression and activity of microRNA (miRNAs) represents an emerging translational framework for the development of such innovative therapies because changes in the expression of one miRNA can have wide-ranging effects on diverse cellular processes associated with disease. In this short review, the roles of miRNA in epidermal development, psoriasis, cutaneous squamous cell carcinoma and re-epithelisation are highlighted. Consideration is given to the delivery of oligonucleotides that mimic or inhibit miRNA function using vehicles such as cell penetrating peptides, spherical nucleic acids, deformable liposomes and liquid crystalline nanodispersions. Formulation of miRNA-directed oligonucleotides with such skin-penetrating epidermal agents will drive the development of RNA-based cutaneous therapeutics for deployment as primary or adjuvant therapies for epidermal disorders.

Facial microcirculatory and biomechanical skin properties after single high energy (Er):YAG laser application

OBJECTIVE

Owing to skin aging and the growing demand for skin rejuvenation, minimal invasive aesthetic treatments such as laser procedures are increasingly coming into focus. However, until now, little has been known about the objective effects of these procedures with respect to skin microcirculation or changes in skin elasticity.

STUDY DESIGN

Facial skin rejuvenation was performed on 32 volunteers using ablative Erbium: YAG laser. Skin microcirculation and skin elasticity have then been evaluated objectively.

METHODS

Microcirculation (flow, SO₂ , velocity, and rHB) has been analyzed before and directly after the laser session by using the O2C device. Skin elasticity has been evaluated by using the Cutometer device (Uf, Ua, Ur, and Ue) before and directly after the laser treatment, as well as 1 week and then 1, 3, and 6 months post treatment. Further, the outcome for the volunteers regarding their satisfactory level after laser treatment was evaluated.

RESULTS

Twenty volunteers were available for a complete follow-up. Microcirculation displayed statistically significant increase in all values to 2 mm depth. The biomechanical skin parameter of firmness of skin displayed statistically significant improvement in superficial skin layer after 6 months.

CONCLUSION

Concerning microcirculation and skin elasticity the ablative Erbium: YAG laser treatment revealed similar effects on the skin like a superficial burn injury. In contrast to the determined skin elasticity parameters, firmness of skin objectively revealed a skin tightening effect after 6 months. Along with the important epidermal effect, the suitability of ablative laser treatment for skin rejuvenation has been proved in a long-term follow-up. Lasers Surg. Med. 49:891-898, 2017. © 2017 Wiley Periodicals, Inc.

A novel method for non-destructive determination of hair photo-induced damage based on multispectral imaging technology

Extended exposure to sunlight may give rise to chemical and physical damages of human hairs. In this work, we report a novel method for non-destructive quantification of hair photodamage via multispectral imaging (MSI) technology. We show that the multispectral reflectance value in near-infrared region has a strong correlation with hair photodamage. More specifically, the hair segments with longer growing time and the same hair root segment after continuous ultraviolet (UV) irradiation displaying more severe photodamage observed via scanning electron microscopy (SEM) micrographs showed significantly higher multispectral reflectance value. Besides, the multispectral reflectance value of hair segments with different growing time was precisely reproduced by exposing the same hair root segment to specific durations of UV irradiation, suggesting that MSI can be adequately applied to determine the sunlight exposure time of the hair. The loss of cystine content of photodamaged hairs was identified to be the main factor that physiologically contributed to the morphological changes of hair surface fibers and hence the variation of their multispectral reflectance spectra. Considering the environmental information recording nature of hairs, we believe that MSI for non-destructive evaluation of hair photodamage would prove valuable for assessing sunlight exposure time of a subject in the biomedical fields.