High-fat diet reduces levels of type I tropocollagen and hyaluronan in rat skin

A Review of Advancement on Influencing Factors of Acne: An Emphasis on Environment Characteristics

Background: Acne vulgaris is known as a commonly-seen skin disease with a considerable impact on the quality of life. At present, there have been a growing number of epidemiological, medical, demographic and sociological researches focusing on various influencing factors in the occurrence of acne. Nevertheless, the correlation between environmental factors and acne has yet to be fully investigated. Objective: To assess the impacts of individual, natural and social environmental factors on acne and to construct a framework for the potential impact of built environment on acne. Methods: A thorough review was conducted into the published social demographical, epidemiological, and environmental studies on acne through PubMed, Google Scholar and Web of Science, with reference made to the relevant literature. Results: The influencing factors in acne are classed into four major categories. The first one includes individual socio-economic and biological factors, for example, gender, age, economic level, heredity, obesity, skin type, menstrual cycle (for females), diet, smoking, cosmetics products, electronic products, sleep quality and psychological factors. The second one includes such natural environmental factors as temperature, humidity, sun exposure, air pollution and chloracne. The third one relates to social environment, including social network and social media. The last one includes built environmental factors, for example, population density, food stores, green spaces, as well as other built environment characteristics for transport. Acne can be affected negatively by family history, overweight, obesity, oily or mixed skin, irregular menstrual cycles, sugary food, greasy food, dairy products, smoking, the improper use of cosmetics, the long-term use of electronics, the poor quality of sleep, stress, high temperature, sun exposure, air pollution, mineral oils and halogenated hydrocarbons. Apart from that, there are also potential links between built environment and acne. Conclusions: It is necessary to determine the correlation between the built environment and acne based on the understanding of the impact of traditional factors (sociology of population and environment) on acne gained by multidisciplinary research teams. Moreover, more empirical studies are required to reveal the specific relationship between built environment and acne.

Microsatellite polymorphism in the Heme oxygenase-1 gene promoter is associated with dermal collagen density in Japanese obese male subjects

We previously reported elevated oxidative stress-related mechanical vulnerabilities of the skin as sparse distributions of hyperechoic areas. Although this helped establish a personalized skin care system to prevent skin disorders related to mechanical stress, obesity-related skin vulnerability involves individual differences. Here, we hypothesized that individual differences are caused by polymorphisms of GT repetitive sequences in the heme oxygenase1 (HMOX1) promoter region, which encodes an antioxidant enzyme. This cross-sectional study enrolled healthy male volunteers in a walking classroom aimed at weight control. Subjects with a body mass index <25 kg/m² were classified as non-obese and those with body mass index ≥25 kg/m² were classified as obese. Subject skin was categorized into sparse dermis or normal groups according to the distribution of hyperechoic areas by high-resolution skin ultrasonography (20 MHz). Genomic DNA and mRNA extracted from three body hairs with attached follicle cells were used to analyze GT repetitive sequences of the HMOX1 promoter, HMOX1 mRNA expression levels, and oxidative stress levels (8-hydroxy-2’-deoxyguanosine). Classifications of GT repetitive sequence of HMOX1 promoter were Short (<27 times) and Long (≥27 times). Higher numbers of subjects with sparse dermis were in the obese group compared with the non-obese group. In obese subjects, the number of subjects that had the Long allele of the HMOX1 promoter with sparse dermis was significantly higher compared with the normal group, whereas no association was observed between the polymorphism and ultrasonographic features in non-obese subjects. Thus, HMOX1 polymorphisms detected a risk of low collagen density in Japanese obese male subjects.

Aging-like physiological changes in the skin of Japanese obese diabetic patients

Objective:

Obesity-associated diabetes causes aging-like changes to skin physiology in animal models, but there have been no clinical studies focusing on human obese diabetic patients. The purpose of this study was to examine the hypothesis that obesity-associated diabetes accelerates aging-like skin changes in Japanese people.

Methods:

This cross-sectional study enrolled obese-diabetes patients (body mass index ≥ 25 kg m−2) and healthy volunteers (body mass index < 25 kg m⁻²) as controls. Skin physiology parameters relating to aging (stratum corneum hydration, transepidermal water loss, skin pH, advanced glycation end-products, and dermal collagen density) were evaluated in the two groups.

Results:

About 37 subjects participated (16 in a control group and 21 in an obese-diabetes group). Age was not significantly different between the groups. The stratum corneum hydration level was significantly lower in the obese-diabetes group. Transepidermal water loss and levels of advanced glycation end-products were significantly higher in this group. Skin pH was not significantly different between groups. Dermal collagen density decreased in the obese-diabetes group.

Conclusion:

We showed that obese-diabetes patients have decreased stratum corneum hydration, increased transepidermal water loss, higher skin advanced glycation end-products and decreased dermal collagen fiber density compared with normal-weight subjects. These results indicate that the ordinary age-related physiological skin changes seen in the elderly can also occur in obese-diabetes patients aged in their 40s.

The Effects of Dietary Macronutrient Balance on Skin Structure in Aging Male and Female Mice

Nutrition influences skin structure; however, a systematic investigation into how energy and macronutrients (protein, carbohydrate and fat) affects the skin has yet to be conducted. We evaluated the associations between macronutrients, energy intake and skin structure in mice fed 25 experimental diets and a control diet for 15 months using the Geometric Framework, a novel method of nutritional analysis. Skin structure was associated with the ratio of dietary macronutrients eaten, not energy intake, and the nature of the effect differed between the sexes. In males, skin structure was primarily associated with protein intake, whereas in females carbohydrate intake was the primary correlate. In both sexes, the dermis and subcutaneous fat thicknesses were inversely proportional. Subcutaneous fat thickness varied positively with fat intake, due to enlarged adipocytes rather than increased adipocyte number. We therefore demonstrated clear interactions between skin structure and macronutrient intakes, with the associations being sex-specific and dependent on dietary macronutrient balance.

More than just a filler - the role of hyaluronan for skin homeostasis

In recent years, hyaluronan (HA) has become an increasingly attractive substance as a non-immunogenic filler and scaffolding material in cosmetic dermatology. Despite its wide use for skin augmentation and rejuvenation, relatively little is known about the molecular structures and interacting proteins of HA in normal and diseased skin. However, a comprehensive understanding of cutaneous HA homeostasis is required for future the development of HA-based applications for skin regeneration. This review provides an update on HA-based structures, expression, metabolism and its regulation, function and pharmacological targeting of HA in skin.

Ultraviolet B irradiation reduces the expression of adiponectin in ovarial adipose tissues through endocrine actions of calcitonin gene-related peptide-induced serum amyloid A

Ultraviolet (UV) B irradiation decreases blood adiponectin levels, but the mechanism is not well understood. This study investigated how UVB irradiation reduces adiponectin expression in ovarial adipose tissues. Female Hos:HR-1 hairless mice were exposed to UVB (1.6 J/cm²) irradiation and were killed 24 h later. UVB irradiation decreased the adiponectin protein level in the serum and the adiponectin mRNA level in ovarial adipose tissues. UVB irradiation also decreased the mRNA levels of peroxisome proliferator-activated receptor (PPAR) γ, CCAAT/enhancer binding protein (C/EBP) α, C/EBPβ, and fatty acid binding protein 4 (aP2) in ovarial adipose tissues. In contrast, UVB irradiation increased the mRNA levels of interleukin (IL)-6 and monocyte chemoattractant protein (MCP)-1 in ovarial adipose tissues. In the serum and liver, the levels of serum amyloid A (SAA), involved in PPARγ, C/EBPα, C/EBPβ, aP2, IL-6, and MCP-1 regulation, increased after UVB irradiation. The SAA gene is regulated by IL-1β, IL-6, and tumor necrosis factor-α, but only IL-6 expression increased in the liver after UVB irradiation. Additionally, in the liver, hypothalamus, and epidermis, UVB irradiation increased the expression of calcitonin gene-related peptide (CGRP), which upregulates SAA in the liver. Collectively, our results suggest that the CGRP signal induced by skin exposure to UVB transfers to the liver, possibly through the brain, and increases SAA production via IL-6 in the liver. In turn, serum SAA acts in an endocrine manner to decreases the serum adiponectin level by downregulating factors that regulate adiponectin expression in adipose tissues.

Adiponectin promotes hyaluronan synthesis along with increases in hyaluronan synthase 2 transcripts through an AMP-activated protein kinase/peroxisome proliferator-activated receptor-α-dependent pathway in human dermal fibroblasts

Although adipocytokines affect the functions of skin, little information is available on the effect of adiponectin on the skin. In this study, we investigated the effect of adiponectin on hyaluronan synthesis and its regulatory mechanisms in human dermal fibroblasts. Adiponectin promoted hyaluronan synthesis along with an increase in the mRNA levels of hyaluronan synthase 2 (HAS2), which plays a primary role in hyaluronan synthesis. Adiponectin also increased the phosphorylation of AMP-activated protein kinase (AMPK). A pharmacological activator of AMPK, 5-aminoimidazole-4-carboxamide-1β-ribofuranoside (AICAR), increased mRNA levels of peroxisome proliferator-activated receptor-α (PPARα), which enhances the expression of HAS2 mRNA. In addition, AICAR increased the mRNA levels of HAS2. Adiponectin-induced HAS2 mRNA expression was blocked by GW6471, a PPARα antagonist, in a concentration-dependent manner. These results show that adiponectin promotes hyaluronan synthesis along with increases in HAS2 transcripts through an AMPK/PPARα-dependent pathway in human dermal fibroblasts. Thus, our study suggests that adiponectin may be beneficial for retaining moisture in the skin, anti-inflammatory activity, and the treatment of a variety of cutaneous diseases.

A high-fat diet reduces ceramide synthesis by decreasing adiponectin levels and decreases lipid content by modulating HMG-CoA reductase and CPT-1 mRNA expression in the skin

SCOPE

Molecules involved in skin function are greatly affected by nutritional conditions. However, the mechanism linking high-fat (HF) diets with these alterations is not well understood. This study aimed to investigate the molecular changes in skin function that result from HF diets.

METHODS AND RESULTS

Sprague-Dawley rats were fed HF diets for 28 days. The skin levels of ceramide, lipids and mRNAs involved in lipid metabolism were evaluated using TLC, oil red O staining and quantitative PCR, respectively. The serum adiponectin concentration was determined by ELISA. HF diets led to reduced ceramide levels and lowered skin lipid content. They also decreased mRNA levels of serine palmitoyltransferase (SPT) and 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase in the skin and those of peroxisome proliferator-activated receptor-α -PPAR-α), which upregulates SPT and HMG-CoA reductase expression. The HF diets reduced the serum concentration of adiponectin, which acts upstream of PPAR-α. Finally, these diets led to increased mRNA levels of carnitine palmitoyltransferase-1, the rate-limiting enzyme that acts in β-oxidation.

CONCLUSION

Our study suggests that HF diets reduce ceramide and lipid synthesis in the skin by reducing levels of SPT and HMG-CoA reductase through lowered adiponectin and PPAR-α activity. Additionally, they decrease lipid content by enhancing β-oxidation.