Skin age testing criteria: characterization of human skin structures by 500 MHz MRI multiple contrast and image processing

NASA Astrophysics Data System (ADS)

Sharma, Rakesh

2010-07-01

Ex vivo magnetic resonance microimaging (MRM) image characteristics are reported in human skin samples in different age groups. Human excised skin samples were imaged using a custom coil placed inside a 500 MHz NMR imager for high-resolution microimaging. Skin MRI images were processed for characterization of different skin structures. Contiguous cross-sectional T1-weighted 3D spin echo MRI, T2-weighted 3D spin echo MRI and proton density images were compared with skin histopathology and NMR peaks. In all skin specimens, epidermis and dermis thickening and hair follicle size were measured using MRM. Optimized parameters TE and TR and multicontrast enhancement generated better MRI visibility of different skin components. Within high MR signal regions near to the custom coil, MRI images with short echo time were comparable with digitized histological sections for skin structures of the epidermis, dermis and hair follicles in 6 (67%) of the nine specimens. Skin % tissue composition, measurement of the epidermis, dermis, sebaceous gland and hair follicle size, and skin NMR peaks were signatures of skin type. The image processing determined the dimensionality of skin tissue components and skin typing. The ex vivo MRI images and histopathology of the skin may be used to measure the skin structure and skin NMR peaks with image processing may be a tool for determining skin typing and skin composition.

Detection of advanced glycation end products (AGEs) on human skin by in vivo confocal Raman spectroscopy

NASA Astrophysics Data System (ADS)

Martin, A. A.; Pereira, L.; Ali, S. M.; Pizzol, C. D.; Tellez, C. A.; Favero, P. P.; Santos, L.; da Silva, V. V.; Praes, C. E. O.

2016-03-01

The aging process involves the reduction in the production of the major components of skin tissue. During intrinsic aging and photoaging processes, in dermis of human skin, fibroblasts become senescent and have decreased activity, which produce low levels of collagen. Moreover, there is accumulation of advanced glycation end products (AGEs). AGEs have incidence in the progression of age-related diseases, principally in diabetes mellitus and in Alzheimer's diseases. AGEs causes intracellular damage and/or apoptosis leading to an increase of the free radicals, generating a crosslink with skin proteins and oxidative stress. The aim of this study is to detect AGEs markers on human skin by in vivo Confocal Raman spectroscopy. Spectra were obtained by using a Rivers Diagnostic System, 785 nm laser excitation and a CCD detector from the skin surface down to 120 μm depth. We analyzed the confocal Raman spectra of the skin dermis of 30 women volunteers divided into 3 groups: 10 volunteers with diabetes mellitus type II, 65-80 years old (DEW); 10 young healthy women, 20-33 years old (HYW); and 10 elderly healthy women, 65-80 years old (HEW). Pentosidine and glucosepane were the principally identified AGEs in the hydroxyproline and proline Raman spectral region (1000-800 cm-1), in the 1.260-1.320 cm-1 region assignable to alpha-helical amide III modes, and in the Amide I region. Pentosidine and glucosepane calculated vibrational spectra were performed through Density Functional Theory using the B3LYP functional with 3-21G basis set. Difference between the Raman spectra of diabetic elderly women and healthy young women, and between healthy elderly women and healthy young women were also obtained with the purpose of identifying AGEs Raman bands markers. AGEs peaks and collagen changes have been identified and used to quantify the glycation process in human skin.

Age-associated decrease in GDNF and its cognate receptor GFRα-1 protein expression in human skin.

PubMed

Adly, Mohamed A; Assaf, Hanan A; Hussein, Mahmoud Rezk Abdelwahed

2016-06-01

Glial cell line-derived neurotrophic factor (GDNF) and its cognate receptor (GFRα-1) are expressed in normal human skin. They are involved in murine hair follicle morphogenesis and cycling control. We hypothesize that 'GDNF and GFRα-1 protein expression in human skin undergoes age-associated alterations. To test our hypothesis, the expression of these proteins was examined in human skin specimens obtained from 30 healthy individuals representing three age groups: children (5-18 years), adults (19-60 years) and the elderly (61-81 years). Immunofluorescent and light microscopic immunohistologic analyses were performed using tyramide signal amplification and avidin-biotin complex staining methods respectively. GDNF mRNA expression was examined by RT-PCR analysis. GDNF mRNA and protein as well as GFRα-1 protein expressions were detected in normal human skin. We found significantly reduced epidermal expression of these proteins with ageing. In the epidermis, the expression was strong in the skin of children and declined gradually with ageing, being moderate in adults and weak in the elderly. In children and adults, the expression of both GDNF and GFRα-1 proteins was strongest in the stratum basale and decreased gradually towards the surface layers where it was completely absent in the stratum corneum. In the elderly, GDNF and GFRα-1 protein expression was confined to the stratum basale. In the dermis, both GDNF and GFRα-1 proteins had strong expressions in the fibroblasts, sweat glands, sebaceous glands, hair follicles and blood vessels regardless of the age. Thus there is a decrease in epidermal GDNF and GFRα-1 protein expression in normal human skin with ageing. Our findings suggest that the consequences of this is that GFRα-1-mediated signalling is altered during the ageing process. The clinical and therapeutic ramifications of these observations mandate further investigations. © 2016 The Authors. International Journal of Experimental Pathology © 2016

Skin anti-aging strategies

PubMed Central

Ganceviciene, Ruta; Liakou, Aikaterini I.; Theodoridis, Athanasios; Makrantonaki, Evgenia; Zouboulis, Christos C.

2012-01-01

Skin aging is a complex biological process influenced by a combination of endogenous or intrinsic and exogenous or extrinsic factors. Because of the fact that skin health and beauty is considered one of the principal factors representing overall “well-being” and the perception of “health” in humans, several anti-aging strategies have been developed during the last years. It is the intention of this article to review the most important anti-aging strategies that dermatologists have nowadays in hand, including including preventive measurements, cosmetological strategies, topical and systemic therapeutic agents and invasive procedures. PMID:23467476

Novel aspects of intrinsic and extrinsic aging of human skin: beneficial effects of soy extract.

PubMed

Südel, Kirstin M; Venzke, Kirsten; Mielke, Heiko; Breitenbach, Ute; Mundt, Claudia; Jaspers, Sören; Koop, Urte; Sauermann, Kirsten; Knussman-Hartig, Elke; Moll, Ingrid; Gercken, Günther; Young, Anthony R; Stäb, Franz; Wenck, Horst; Gallinat, Stefan

2005-01-01

Biochemical and structural changes of the dermal connective tissue substantially contribute to the phenotype of aging skin. To study connective tissue metabolism with respect to ultraviolet (UV) exposure, we performed an in vitro (human dermal fibroblasts) and an in vivo complementary DNA array study in combination with protein analysis in young and old volunteers. Several genes of the collagen metabolism such as Collagen I, III and VI as well as heat shock protein 47 and matrix metalloproteinase-1 are expressed differentially, indicating UV-mediated effects on collagen expression, processing and degradation. In particular, Collagen I is time and age dependently reduced after a single UV exposure in human skin in vivo. Moreover, older subjects display a lower baseline level and a shorter UV-mediated increase in hyaluronan (HA) levels. To counteract these age-dependent changes, cultured fibroblasts were treated with a specific soy extract. This treatment resulted in increased collagen and HA synthesis. In a placebo-controlled in vivo study, topical application of an isoflavone-containing emulsion significantly enhanced the number of dermal papillae per area after 2 weeks. Because the flattening of the dermal-epidermal junction is the most reproducible structural change in aged skin, this soy extract appears to rejuvenate the structure of mature skin.

Attenuated noradrenergic sensitivity during local cooling in aged human skin

PubMed Central

Thompson, Caitlin S; Holowatz, Lacy A; Kenney, W. Larry

2005-01-01

Reflex-mediated cutaneous vasoconstriction (VC) is impaired in older humans; however, it is unclear whether this blunted VC also occurs during local cooling, which mediates VC through different mechanisms. We tested the hypothesis that the sensitization of cutaneous vessels to noradrenaline (NA) during direct skin cooling seen in young skin is blunted in aged skin. In 11 young (18–30 years) and 11 older (62–76 years) men and women, skin blood flow was monitored at two forearm sites with laser Doppler (LD) flowmetry while local skin temperature was cooled and clamped at 24°C. Cutaneous vascular conductance (CVC; LD flux/mean arterial pressure) was expressed as percentage change from baseline (%ΔCVCbase). At one site, five doses of NA (10−10–10−2m) were sequentially infused via intradermal microdialysis during cooling while the other 24°C site served as control (Ringer solution + cooling). At control sites, VC due to cooling alone was similar in young versus older (−54 ± 5 versus −56 ± 3%ΔCVCbase, P= 0.46). In young, NA infusions induced additional dose-dependent VC (10−8, 10−6, 10−4 and 10−2m: −70 ± 2, −72 ± 3, −78 ± 3 and −79 ± 4%ΔCVCbase; P < 0.05 versus control). In older subjects, further VC did not occur until the highest infused dose of NA (10−2m: −70 ± 5%ΔCVCbase; P < 0.05 versus control). When cutaneous arterioles are sensitized to NA by direct cooling, young skin exhibits the capacity to further constrict to NA in a dose-dependent manner. However, older skin does not display enhanced VC capacity until treated with saturating doses of NA, possibly due to age-associated decrements in Ca2+ availability or α2C-adrenoceptor function. PMID:15705648

Oral sapropterin augments reflex vasoconstriction in aged human skin through noradrenergic mechanisms.

PubMed

Stanhewicz, Anna E; Alexander, Lacy M; Kenney, W Larry

2013-10-01

Reflex vasoconstriction is attenuated in aged skin due to a functional loss of adrenergic vasoconstriction. Bioavailability of tetrahydrobiopterin (BH4), an essential cofactor for catecholamine synthesis, is reduced with aging. Locally administered BH4 increases vasoconstriction through adrenergic mechanisms in aged human skin. We hypothesized that oral sapropterin (Kuvan, a pharmaceutical BH4) would augment vasoconstriction elicited by whole-body cooling and tyramine perfusion in aged skin. Ten healthy subjects (age 75 ± 2 yr) ingested sapropterin (10 mg/kg) or placebo in a randomized, double-blind crossover design. Venous blood samples were collected prior to, and 3 h following ingestion. Three intradermal microdialysis fibers were placed in the forearm skin for local delivery of 1) lactated Ringer, 2) 5 mM BH4, and 3) 5 mM yohimbine + 1 mM propranolol (Y+P; to inhibit adrenergic vasoconstriction). Red cell flux was measured at each site by laser-Doppler flowmetry (LDF) as reflex vasoconstriction was induced by lowering and then clamping whole-body skin temperature (Tsk) using a water-perfused suit. Following whole-body cooling, subjects were rewarmed and 1 mM tyramine was perfused at each site to elicit endogenous norepinephrine release from the perivascular nerve terminal. Cutaneous vascular conductance was calculated as CVC = LDF/mean arterial pressure and expressed as change from baseline (ΔCVC). Plasma BH4 was elevated 3 h after ingestion of sapropterin (43.8 ± 3 vs. 19.1 ± 2 pmol/ml; P < 0.001). Sapropterin increased reflex vasoconstriction at the Ringer site at Tsk ≤ 32.5°C (P < 0.05). Local BH4 perfusion augmented reflex vasoconstriction at Tsk ≤ 31.5°C with placebo treatment only (P < 0.05). There was no treatment effect on reflex vasoconstriction at the BH4-perfused or Y+P-perfused sites. Sapropterin increased pharmacologically induced vasoconstriction at the Ringer site (-0.19 ± 0.03 vs. -0.08 ± 0.02 ΔCVC; P = 0.01). There was no

Tubulin Beta-3 Chain as a New Candidate Protein Biomarker of Human Skin Aging: A Preliminary Study

PubMed Central

2017-01-01

Skin aging is a complex process, and a lot of efforts have been made to identify new and specific targets that could help to diagnose, prevent, and treat skin aging. Several studies concerning skin aging have analyzed the changes in gene expression, and very few investigations have been performed at the protein level. Moreover, none of these proteomic studies has used a global quantitative labeled proteomic offgel approach that allows a more accurate description of aging phenotype. We applied such an approach on human primary keratinocytes obtained from sun-nonexposed skin biopsies of young and elderly women. A total of 517 unique proteins were identified, and 58 proteins were significantly differentially expressed with 40 that were downregulated and 18 upregulated with aging. Gene ontology and pathway analysis performed on these 58 putative biomarkers of skin aging evidenced that these dysregulated proteins were mostly involved in metabolism and cellular processes such as cell cycle and signaling pathways. Change of expression of tubulin beta-3 chain was confirmed by western blot on samples originated from several donors. Thus, this study suggested the tubulin beta-3 chain has a promising biomarker in skin aging. PMID:28626498

Tubulin Beta-3 Chain as a New Candidate Protein Biomarker of Human Skin Aging: A Preliminary Study.

PubMed

Lehmann, Sylvia G; Bourgoin-Voillard, Sandrine; Seve, Michel; Rachidi, Walid

2017-01-01

Skin aging is a complex process, and a lot of efforts have been made to identify new and specific targets that could help to diagnose, prevent, and treat skin aging. Several studies concerning skin aging have analyzed the changes in gene expression, and very few investigations have been performed at the protein level. Moreover, none of these proteomic studies has used a global quantitative labeled proteomic offgel approach that allows a more accurate description of aging phenotype. We applied such an approach on human primary keratinocytes obtained from sun-nonexposed skin biopsies of young and elderly women. A total of 517 unique proteins were identified, and 58 proteins were significantly differentially expressed with 40 that were downregulated and 18 upregulated with aging. Gene ontology and pathway analysis performed on these 58 putative biomarkers of skin aging evidenced that these dysregulated proteins were mostly involved in metabolism and cellular processes such as cell cycle and signaling pathways. Change of expression of tubulin beta-3 chain was confirmed by western blot on samples originated from several donors. Thus, this study suggested the tubulin beta-3 chain has a promising biomarker in skin aging.

Characterizing Facial Skin Ageing in Humans: Disentangling Extrinsic from Intrinsic Biological Phenomena

PubMed Central

Trojahn, Carina; Dobos, Gabor; Lichterfeld, Andrea; Blume-Peytavi, Ulrike; Kottner, Jan

2015-01-01

Facial skin ageing is caused by intrinsic and extrinsic mechanisms. Intrinsic ageing is highly related to chronological age. Age related skin changes can be measured using clinical and biophysical methods. The aim of this study was to evaluate whether and how clinical characteristics and biophysical parameters are associated with each other with and without adjustment for chronological age. Twenty-four female subjects of three age groups were enrolled. Clinical assessments (global facial skin ageing, wrinkling, and sagging), and biophysical measurements (roughness, colour, skin elasticity, and barrier function) were conducted at both upper cheeks. Pearson's correlations and linear regression models adjusted for age were calculated. Most of the measured parameters were correlated with chronological age (e.g., association with wrinkle score, r = 0.901) and with each other (e.g., residual skin deformation and wrinkle score, r = 0.606). After statistical adjustment for age, only few associations remained (e.g., mean roughness (R z) and luminance (L *),  β = −0.507, R 2 = 0.377). Chronological age as surrogate marker for intrinsic ageing has the most important influence on most facial skin ageing signs. Changes in skin elasticity, wrinkling, sagging, and yellowness seem to be caused by additional extrinsic ageing. PMID:25767806

Instrumental evaluation of anti-aging effects of cosmetic formulations containing palmitoyl peptides, Silybum marianum seed oil, vitamin E and other functional ingredients on aged human skin.

PubMed

Hahn, Hyung Jin; Jung, Ho Jung; Schrammek-Drusios, Med Christine; Lee, Sung Nae; Kim, Ji-Hyun; Kwon, Seung Bin; An, In-Sook; An, Sungkwan; Ahn, Kyu Joong

2016-08-01

Anti-aging cosmetics are widely used for improving signs of aged skin such as skin wrinkles, decreased elasticity, low dermal density and yellow skin tone. The present study evaluated the effects of cosmetic formulations, eye cream and facial cream, containing palmitoyl peptides, Silybum marianum ( S. marianum ) seed oil, vitamin E and other functional ingredients on the improvement of facial wrinkles, elasticity, dermal density and skin tone after 4 weeks period of application on aged human skin. Healthy volunteers (n=20) with aged skin were recruited to apply the test materials facially twice per day for 4 weeks. Skin wrinkles, elasticity, dermal density and skin tone were measured instrumentally for assessing the improvement of skin aging. All the measurements were conducted prior to the application of test materials and at 2 and 4 weeks of treatment. Crow's feet wrinkles were decreased 5.97% after 2 weeks of test material application and 14.07% after 4 weeks of application in comparison of pre-application. Skin elasticity was increased 6.81% after 2 weeks and 8.79% after 4 weeks. Dermal density was increased 16.74% after 2 weeks and 27.63% after 4 weeks. With the L* value indicating skin brightness and the a* value indicating erythema (redness), the results showed that brightness was increased 1.70% after 2 weeks and 2.14% after 4 weeks, and erythema was decreased 10.45% after 2 weeks and 22.39% after 4 weeks. Hence, the test materials appear to exert some degree of anti-aging effects on aged human skin. There were no abnormal skin responses from the participants during the trial period. We conclude that the facial and eye cream containing palmitoyl peptides and S. marianum seed oil, vitamin E and other ingredients have effects on the improvement of facial wrinkles, elasticity, dermal density and skin tone.

Age-related changes in expression and function of Toll-like receptors in human skin

PubMed Central

Iram, Nousheen; Mildner, Michael; Prior, Marion; Petzelbauer, Peter; Fiala, Christian; Hacker, Stefan; Schöppl, Alice; Tschachler, Erwin; Elbe-Bürger, Adelheid

2012-01-01

Toll-like receptors (TLRs) initiate innate immune responses and direct subsequent adaptive immunity. They play a major role in cutaneous host defense against micro-organisms and in the pathophysiology of several inflammatory skin diseases. To understand the role of TLRs in the acquisition of immunological competence, we conducted a comprehensive study to evaluate TLR expression and function in the developing human skin before and after birth and compared it with adults. We found that prenatal skin already expresses the same spectrum of TLRs as adult skin. Strikingly, many TLRs were significantly higher expressed in prenatal (TLRs 1-5) and infant and child (TLRs 1 and 3) skin than in adult skin. Surprisingly, neither dendritic cell precursors in prenatal skin nor epidermal Langerhans cells and dermal dendritic cells in adult skin expressed TLRs 3 and 6, whereas the staining pattern and intensity of both TLRs in fetal basal keratinocytes was almost comparable to those of adults. Stimulation of primary human keratinocytes from fetal, neonatal and adult donors with selected TLR agonists revealed that the synthetic TLR3 ligand poly (I:C) specifically, mimicking viral double-stranded RNA, induced a significantly enhanced secretion of CXCL8/IL8, CXCL10/IP-10 and TNFα in fetal and neonatal keratinocytes compared with adult keratinocytes. This study demonstrates quantitative age-specific modifications in TLR expression and innate skin immune reactivity in response to TLR activation. Thus, antiviral innate immunity already in prenatal skin may contribute to protect the developing human body from viral infections in utero in a scenario where the adaptive immune system is not yet fully functional. PMID:23034637

AGE-RELATED GENE EXPRESSION CHANGES IN HUMAN SKIN FIBROBLASTS INDUCED BY MMS

EPA Science Inventory

Age-Related Gene Expression Changes In Human Skin Fibroblasts Induced By methyl methanesulfonate. Geremy W. Knapp, Alan H. Tennant, and Russell D. Owen. Environmental Carcinogenesis Division, National Health and Environmental Effects Research Laboratory, U. S. Environmental Prote...

Oral sapropterin augments reflex vasoconstriction in aged human skin through noradrenergic mechanisms

PubMed Central

Stanhewicz, Anna E.; Kenney, W. Larry

2013-01-01

Reflex vasoconstriction is attenuated in aged skin due to a functional loss of adrenergic vasoconstriction. Bioavailability of tetrahydrobiopterin (BH4), an essential cofactor for catecholamine synthesis, is reduced with aging. Locally administered BH4 increases vasoconstriction through adrenergic mechanisms in aged human skin. We hypothesized that oral sapropterin (Kuvan, a pharmaceutical BH4) would augment vasoconstriction elicited by whole-body cooling and tyramine perfusion in aged skin. Ten healthy subjects (age 75 ± 2 yr) ingested sapropterin (10 mg/kg) or placebo in a randomized, double-blind crossover design. Venous blood samples were collected prior to, and 3 h following ingestion. Three intradermal microdialysis fibers were placed in the forearm skin for local delivery of 1) lactated Ringer, 2) 5 mM BH4, and 3) 5 mM yohimbine + 1 mM propranolol (Y+P; to inhibit adrenergic vasoconstriction). Red cell flux was measured at each site by laser-Doppler flowmetry (LDF) as reflex vasoconstriction was induced by lowering and then clamping whole-body skin temperature (T̄sk) using a water-perfused suit. Following whole-body cooling, subjects were rewarmed and 1 mM tyramine was perfused at each site to elicit endogenous norepinephrine release from the perivascular nerve terminal. Cutaneous vascular conductance was calculated as CVC = LDF/mean arterial pressure and expressed as change from baseline (ΔCVC). Plasma BH4 was elevated 3 h after ingestion of sapropterin (43.8 ± 3 vs. 19.1 ± 2 pmol/ml; P < 0.001). Sapropterin increased reflex vasoconstriction at the Ringer site at T̄sk ≤ 32.5°C (P < 0.05). Local BH4 perfusion augmented reflex vasoconstriction at T̄sk ≤ 31.5°C with placebo treatment only (P < 0.05). There was no treatment effect on reflex vasoconstriction at the BH4-perfused or Y+P-perfused sites. Sapropterin increased pharmacologically induced vasoconstriction at the Ringer site (−0.19 ± 0.03 vs. −0.08 ± 0.02 ΔCVC; P = 0.01). There was no

Lower levels of interleukin-1β gene expression are associated with impaired Langerhans' cell migration in aged human skin.

PubMed

Pilkington, Suzanne M; Ogden, Stephanie; Eaton, Laura H; Dearman, Rebecca J; Kimber, Ian; Griffiths, Christopher E M

2018-01-01

Langerhans' cells (LC) play pivotal roles in skin immune responses, linking innate and adaptive immunity. In aged skin there are fewer LC and migration is impaired compared with young skin. These changes may contribute to declining skin immunity in the elderly, including increased skin infections and skin cancer. Interleukin-1β (IL-1β) and tumour necrosis factor-α (TNF-α) are mandatory signals for LC migration and previous studies suggest that IL-1β signalling may be dysregulated in aged skin. Therefore, we sought to explore the mechanisms underlying these phenomena. In skin biopsies of photoprotected young (< 30 years) and aged (> 70 years) human skin ex vivo, we assessed the impact of trauma, and mandatory LC mobilizing signals on LC migration and gene expression. Biopsy-related trauma induced LC migration from young epidermis, whereas in aged skin, migration was greatly reduced. Interleukin-1β treatment restored LC migration in aged epidermis whereas TNF-α was without effect. In uncultured, aged skin IL-1β gene expression was lower compared with young skin; following culture, IL-1βmRNA remained lower in aged skin under control and TNF-α conditions but was elevated after culture with IL-1β. Interleukin-1 receptor type 2 (IL1R2) gene expression was significantly increased in aged, but not young skin, after cytokine treatment. Keratinocyte-derived factors secreted from young and aged primary cells did not restore or inhibit LC migration from aged and young epidermis, respectively. These data suggest that in aged skin, IL-1β signalling is diminished due to altered expression of IL1B and decoy receptor gene IL1R2. © 2017 The Authors. Immunology Published by John Wiley & Sons Ltd., Immunology.

Ultraviolet Radiation-Induced Skin Aging: The Role of DNA Damage and Oxidative Stress in Epidermal Stem Cell Damage Mediated Skin Aging

PubMed Central

Panich, Uraiwan; Sittithumcharee, Gunya; Rathviboon, Natwarath

2016-01-01

Skin is the largest human organ. Skin continually reconstructs itself to ensure its viability, integrity, and ability to provide protection for the body. Some areas of skin are continuously exposed to a variety of environmental stressors that can inflict direct and indirect damage to skin cell DNA. Skin homeostasis is maintained by mesenchymal stem cells in inner layer dermis and epidermal stem cells (ESCs) in the outer layer epidermis. Reduction of skin stem cell number and function has been linked to impaired skin homeostasis (e.g., skin premature aging and skin cancers). Skin stem cells, with self-renewal capability and multipotency, are frequently affected by environment. Ultraviolet radiation (UVR), a major cause of stem cell DNA damage, can contribute to depletion of stem cells (ESCs and mesenchymal stem cells) and damage of stem cell niche, eventually leading to photoinduced skin aging. In this review, we discuss the role of UV-induced DNA damage and oxidative stress in the skin stem cell aging in order to gain insights into the pathogenesis and develop a way to reduce photoaging of skin cells. PMID:27148370

Effect of estrogens on skin aging and the potential role of SERMs

PubMed Central

Stevenson, Susan; Thornton, Julie

2007-01-01

In humans, structural and functional changes attributable to aging are more visibly evident in the skin than in any other organ. Estrogens have significant effects on skin physiology and modulate epidermal keratinocytes, dermal fibroblasts and melanocytes, in addition to skin appendages including the hair follicle and the sebaceous gland. Importantly, skin aging can be significantly delayed by the administration of estrogen. This paper reviews the effects of estrogens on skin and the mechanisms by which estrogens can alleviate the changes due to aging that occur in human skin. The relevance of estrogen replacement therapy (HRT) in post-menopausal women and the potential value of selective estrogen receptor modulators (SERMs) as a therapy for diminishing skin aging are also highlighted. PMID:18044179

Noninvasive measurement of advanced glycation end-products in the facial skin: New data for skin aging studies.

PubMed

Qu, Di; Venzon, Dawna; Murray, Mary; Depauw, Mathew

Using skin autofluorescence (SAF) as a marker of advanced glycation end-products (AGEs) has been extensively studied in the last decade since the introduction of the noninvasive in vivo measurement technique. Data have shown the level of skin AGEs increases with chronological age in healthy human beings, and this increase is substantially higher in age-matched diabetic patients. In skin research, glycation with the accompanying accumulation of skin AGEs has been regarded as one of the primary skin aging mechanisms that contribute to skin wrinkling and the loss of skin elasticity. To date, the totality of SAF data reported in literature has been obtained from measurements on the arm, and noninvasive measurement of facial skin AGE accumulation would add great value to skin aging research. In this study, we report the levels of facial and forearm skin AGEs in 239 men and women of 21-65 year of age. Significantly lower levels of AGEs were detected in the facial skin than in the forearm skin from the young Caucasian groups, and the difference was much larger for men than for women. The rate of change in skin AGE level over age was found to be about 50% higher in men than in women, which further highlights the gender difference. A statistically significant correlation between the levels of skin AGE and facial wrinkling was also observed. The facial skin AGE data may provide new insight into skin aging research.

Soybean-fragmented proteoglycans against skin aging.

PubMed

Barba, Clara; Alonso, Cristina; Sánchez, Isabel; Suñer, Elisa; Sáez-Martín, L C; Coderch, Luisa

2017-08-01

The majority of age-dependent skin changes happen in the dermis layer inducing changes in skin collagen and in the proteoglycans. The main aim of this work is to study the efficacy of a Proteum serum, containing soybean-fragmented proteoglycans, against skin aging. In vitro tests were performed to evaluate the Proteum serum ability on activating the production of collagen and proteoglycans. An in vivo long-term study was performed to determine the efficacy of the Proteum serum when applied on skin. Protection of healthy skin against detergent-induced dermatitis and the antioxidant properties of the applied Proteum serum were also studied. The in vitro tests demonstrated that the Proteum serum was able to elevate the production of molecules which are essential for supporting the dermal extracellular matrix organization. These results were correlated by the in vivo measurements where a clear trend on improving the measured skin parameters due to the Proteum serum application was found. A beneficial effect of the Proteum serum was demonstrated with an improvement in the skin roughness and a reinforcement of the skin barrier function. Moreover, a significant protector effect on human stratum corneum against lipids peroxides (LPO) was demonstrated.

Mechanisms of skin aging induced by EGFR inhibitors.

PubMed

Gerber, Peter Arne; Buhren, Bettina Alexandra; Schrumpf, Holger; Hevezi, Peter; Bölke, Edwin; Sohn, Dennis; Jänicke, Reiner U; Belum, Viswanath Reddy; Robert, Caroline; Lacouture, Mario E; Homey, Bernhard

2016-10-01

The mechanisms of skin aging have not been completely elucidated. Anecdotal data suggests that EGFR inhibition accelerates aging-like skin changes. The objective of the study was to evaluate the clinical characteristics and investigate the cellular and molecular mechanisms underlying skin changes associated with the use of EFGRIs. Patients during prolonged treatment with EGFRIs (>3 months) were analyzed for aging-like skin changes. Baseline EGFR expression was compared in young (<25 years old) vs. old (> 65 years old) skin. In addition, the regulation of extracellular matrix, senescence-associated genes, and cell cycle status was measured in primary human keratinocytes treated with erlotinib in vitro. There were progressive signs of skin aging, including xerosis cutis, atrophy, rhytide formation, and/or actinic purpura in 12 patients. Keratinocytes treated with erlotinib in vitro showed a significant down-modulation of hyaluronan synthases (HAS2 and HAS3), whereas senescence-associated genes (p21, p53, IL-6, maspin) were upregulated, along with a G1 cell cycle arrest and stronger SA β-Gal activity. There was significantly decreased baseline expression in EGFR density in aged skin, when compared to young controls. EGFR inhibition results in molecular alterations in keratinocytes that may contribute to the observed skin aging of patients treated with respective targeted agents.

Mechanisms of skin aging induced by EGFR inhibitors

PubMed Central

Gerber, Peter Arne; Buhren, Bettina Alexandra; Schrumpf, Holger; Hevezi, Peter; Bölke, Edwin; Sohn, Dennis; Jänicke, Reiner; Belum, Viswanath Reddy; Robert, Caroline; Lacouture, Mario E.; Homey, Bernhard

2017-01-01

BACKGROUND The mechanisms of skin aging have not been completely elucidated. Anecdotal data suggests that EGFR inhibition accelerates aging-like skin changes. OBJECTIVE To evaluate the clinical characteristics and investigate the cellular and molecular mechanisms underlying skin changes associated with the use of EFGRIs. PATIENTS AND METHODS Patients during prolonged treatment with EGFRIs (>3 months) were analyzed for aging-like skin changes. Baseline EGFR expression was compared in young (< 25 years old) vs. old (> 65 years old) skin. In addition, the regulation of extracellular matrix, senescence-associated genes, and cell cycle status was measured in primary human keratinocytes treated with erlotinib in vitro. RESULTS Progressive signs of skin aging, including xerosis cutis, atrophy, rhytide formation and/or actinic purpura in 12 patients. Keratinocytes treated with erlotinib in vitro showed a significant down-modulation of hyaluronan synthases (HAS2 and HAS3), whereas senescence-associated genes (p21, p53, IL-6, maspin) were upregulated, along with a G1 cell cycle arrest and stronger SA β-Gal activity. There was significantly decreased baseline expression in EGFR-density in aged skin, when compared to young controls. CONCLUSIONS EGFR inhibition results in molecular alterations in keratinocytes that may contribute to the observed skin aging of patients treated with respective targeted agents. PMID:27165055

Pigmentation in African American skin decreases with skin aging.

PubMed

Chien, Anna L; Suh, Jean; Cesar, Sabrina Sisto Alessi; Fischer, Alexander H; Cheng, Nancy; Poon, Flora; Rainer, Barbara; Leung, Sherry; Martin, Jo; Okoye, Ginette A; Kang, Sewon

2016-10-01

Tristimulus colorimetry, which uses the Commission Internationale de l'Eclairage L*a*b* model to quantify color, has previously been used to analyze pigmentation and erythema in human skin; however, colorimetry of African American skin is not well characterized. We sought to analyze skin color patterns in African Americans and compare them with those of Caucasians. Colorimetry readings of the sun-protected buttock and sun-exposed back of forearm were taken from 40 Caucasian and 43 African American participants from March 2011 through August 2015. African American participants also completed a lifestyle questionnaire. Correlation coefficients, paired t tests, and multivariable linear regression analyses were used for statistical comparisons. Forearm skin was lighter in African Americans ages 65 years and older versus 18 to 30 years (P = .02) but darker in Caucasians ages 65 years or older versus 18 to 30 years (P = .03). In African Americans ages 18 to 30 years, the buttock was darker than the forearm (P < .001), whereas in Caucasians the buttock was lighter than the forearm (P < .001). A lighter forearm than buttock was correlated with supplement use, smoking (ages 18-30 years), and less recreational sun exposure (ages ≥65 years) in African Americans. Our study was limited by the sample size and focal geographic source. Pigmentation patterns regarding sun-protected and sun-exposed areas in African Americans may differ from that of Caucasians, suggesting that other factors may contribute to skin pigmentation in African Americans. Copyright © 2016 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

Automatic measurement of skin textures of the dorsal hand in evaluating skin aging.

PubMed

Gao, Qian; Yu, Jiaming; Wang, Fang; Ge, Tiantian; Hu, Liwen; Liu, Yang

2013-05-01

Changes in skin textures have been used to evaluate skin aging in many studies. In our previous study, we built some skin texture parameters, which can be used to evaluate skin aging of human dorsal hand. However, it will take too much time and need to work arduously to get the information from digital skin image by manual work. So, we want to build a simple and effective method to automatically count some of those skin texture parameters by using digital image-processing technology. A total of 100 subjects aged 30 years and above were involved. Sun exposure history and demographic information were collected by using a questionnaire. The skin image of subjects' dorsal hand was obtained by using a portable skin detector. The number of grids, which is one of skin texture parameters built in our previous study, was measured manually and automatically. Automated image analysis program was developed by using Matlab 7.1 software. The number of grids counted automatically (NGA) was significantly correlated with the number of grids counted manually (NGM) (r = 0.9287, P < 0.0001). And in each age group, there were no significant differences between NGA and NGM. The NGA was negatively correlated with age and lifetime sun exposure, and decreased with increasing Beagley-Gibson score from 3 to 6. In addition, even after adjusting for NGA, the standard deviation of grid areas for each image was positively correlated with age, sun exposure, and Bealey-Gibson score. The method introduced in present study can be used to measure some skin aging parameters automatically and objectively. And it will save much time, reduce labor, and avoid measurement errors of deferent investigators when evaluating a great deal of skin images in a short time. © 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

AGEs trigger autophagy in diabetic skin tissues and fibroblasts.

PubMed

Sun, Kan; Wang, Wei; Wang, Chuan; Lao, Guojuan; Liu, Dan; Mai, Lifang; Yan, Li; Yang, Chuan; Ren, Meng

2016-03-11

Accumulation of advanced glycation end products (AGEs) contributes to the development of diabetic ulcers. Recent evidence indicates that AGEs administration enhanced autophagy in many cell types. As a positive trigger of autophagy, the effect of AGEs on autophagy in skin tissues and fibroblasts remains unknown. Skin tissues were isolated from Spreqne-Dawley rats and immunohistochemical staining was performed to analyze the location of LC3 and FOXO1 in skin tissues. Then primary cultured foreskin fibroblast cells with treated with AGEs and the effect of AGEs on autophagy was investigated. Protein level expressions of LC3, Beclin-1 and FOXO1 in fibroblasts were analyzed by Western blotting. Autophagic flux is detected with autophagy inhibitor chloroquine and mRFP-GFP-LC3 tandem construct. Compared with skin from normal rats, immunohistochemical staining shows a predominant LC3 localization in fibroblasts cytoplasm in diabetic rats. Elevated expression of FOXO1 also existed in diabetic rats dermis fibroblasts when compared with normal rats in immunohistochemical analysis. In human skin fibroblasts cells, AGEs administration stimulated the autophagy related LC3-II/LC3-I and Beclin-1 expressions and increased autophagy flux. In mRFP-GFP-LC3 puncta formation assays, both autolysosome and autophagosome were increased in human fibroblasts after treatment with AGEs. Fibroblasts exposed to AGEs also have increased FOXO1 expression compared with control group. AGEs could induce autophagy at least in part via regulating the FOXO1 activity in diabetic skin tissues and fibroblasts. Copyright © 2016 Elsevier Inc. All rights reserved.

The chromene sargachromanol E inhibits ultraviolet A-induced ageing of skin in human dermal fibroblasts.

PubMed

Kim, J-A; Ahn, B-N; Kong, C-S; Kim, S-K

2013-05-01

Skin ageing is influenced by environmental factors such as ultraviolet (UV) radiation. The effects of UV radiation on skin functions should be investigated using human in vitro models to understand the mechanisms of skin ageing. Additionally, marine algae provide a valuable source for identifying and extracting biologically active substances. In this study, sargachromanol E was isolated from a marine brown alga, Sargassum horneri, and its inhibitory effect on skin ageing was investigated using UVA-irradiated dermal fibroblasts. Formation of intracellular reactive oxygen species (ROS), lipid peroxidation and protein oxidation induced by UVA irradiation were investigated in UVA-irradiated human dermal fibroblasts. The levels of matrix metalloproteinases (MMPs) were determined by reverse-transcriptase polymerase chain reaction and Western blot analysis. Sargachromanol E did not exhibit any significant cytotoxicity or phototoxicity in UVA-exposed dermal fibroblasts. Additionally, sargachromanol E suppressed intracellular formation of ROS, membrane protein oxidation, lipid peroxidation and expression of collagenases such as MMP-1, MMP-2 and MMP-9, all of which are caused by UVA exposure. It was further found that these inhibitions were related to an increase in the expression of the tissue inhibitor of metalloproteinase (TIMP) genes, TIMP1 and TIMP2. Moreover, we have shown that the transcriptional activation of activator protein 1 (AP-1) signalling caused by UVA irradiation was inhibited by treatment with sargachromanol E. This study suggests that UVA irradiation modulates MMP expression via the transcriptional activation of AP-1 signalling, whereas treatment with sargachromanol E protected cell damage caused by UVA irradiation. © 2013 The Authors. BJD © 2013 British Association of Dermatologists.

Mini Review - Phenolics for skin photo-aging.

PubMed

Ali, Atif

2017-07-01

Photo-aging is one of the foremost problems caused by generation of reactive oxygen species when skin is exposed on UV irradiation. In view of that, generation of reactive oxygen species intermingle with proteins, DNA, saccharides and fatty acids triggering oxidative mutilation and effects are in the appearance of distressed cell metabolism, morphological and ultra-structural changes, mistreat on the routes and revisions in the demarcation, propagation and skin apoptosis living cells which leads to photo-aging. Plant phenolics are universally found in both edible and inedible plants and have extended substantial interest as photo-protective for human skin due to their antioxidant activities. The objective of this review is to highlight the use of plant phenolics for their antioxidant activities against photo-aging.

Stressed out mitochondria: the role of mitochondria in ageing and cancer focussing on strategies and opportunities in human skin.

PubMed

Tulah, Asif S; Birch-Machin, Mark A

2013-09-01

Mitochondrial DNA damage has been used as a successful and unique biomarker of tissue stress. A valuable example of this is sun damage in human skin which leads to ageing and skin cancer. The skin is constantly exposed to the harmful effects of sunlight, such as ultraviolet radiation, which causes it to age with observable characteristic features as well as clinical precancerous lesions and skin cancer. Formation of free radicals by the sun's harmful rays which contribute to oxidative stress has been linked to the induction of deletions and mutations in the mitochondrial DNA. These markers of mitochondrial DNA damage have been proposed to contribute to the mechanisms of ageing in many tissues including skin and are associated with many diseases including cancer. In this article we highlight the role of this important organelle in ageing and cancer with particular emphasis on experimental strategies in the skin. Copyright © 2012 © Elsevier B.V. and Mitochondria Research Society. All rights reserved. Published by Elsevier B.V. All rights reserved.

Anti-Aging Potential of Phytoextract Loaded-Pharmaceutical Creams for Human Skin Cell Longetivity.

PubMed

Jadoon, Saima; Karim, Sabiha; Bin Asad, Muhammad Hassham Hassan; Akram, Muhammad Rouf; Khan, Abida Kalsoom; Malik, Arif; Chen, Chunye; Murtaza, Ghulam

2015-01-01

The exposure to ultraviolet radiations (UVR) is the key source of skin sunburn; it may produce harmful entities, reactive oxygen species (ROS), leading to aging. The skin can be treated and protected from the injurious effects of ROS by using various pharmaceutical formulations, such as cream. Cream can be loaded with antioxidants to quench ROS leading to photo-protective effects. Moreover, modern medicines depend on ethnobotanicals for protection or treatment of human diseases. This review article summarizes various in vivo antioxidant studies on herbal creams loaded with phyto-extracts. These formulations may serve as cosmeceuticals to protect skin against injurious effects of UVR. The botanicals studied for dermatologic use in cream form include Acacia nilotica, Benincasa hispida, Calendula officinalis, Camellia sinensis, Camellia sinensis, Nelumbo nucifera, Capparis decidua, Castanea sativa, Coffea arabica, Crocus sativus, Emblica officinalis Gaertn, Foeniculum vulgare, Hippophae rhamnoides, Lithospermum erythrorhizon, Malus domestica, Matricaria chamomilla L., Moringa oleifera, Morus alba, Ocimum basilicum, Oryza sativa, Polygonum minus, Punica granatum, Silybum marianum, Tagetes erecta Linn., Terminalia chebula, Trigonella foenum-graecum, and Vitis vinifera. The observed anti-aging effects of cream formulations could be an outcome of a coordinating action of multiple constituents. Of numerous botanicals, the phenolic acids and flavonoids appear effective against UVR-induced damage; however the evidence-based studies for their anti-aging effects are still needed.

Anti-Aging Potential of Phytoextract Loaded-Pharmaceutical Creams for Human Skin Cell Longetivity

PubMed Central

Karim, Sabiha; Asad, Muhammad Hassham Hassan Bin; Kalsoom Khan, Abida; Malik, Arif; Chen, Chunye

2015-01-01

The exposure to ultraviolet radiations (UVR) is the key source of skin sunburn; it may produce harmful entities, reactive oxygen species (ROS), leading to aging. The skin can be treated and protected from the injurious effects of ROS by using various pharmaceutical formulations, such as cream. Cream can be loaded with antioxidants to quench ROS leading to photo-protective effects. Moreover, modern medicines depend on ethnobotanicals for protection or treatment of human diseases. This review article summarizes various in vivo antioxidant studies on herbal creams loaded with phyto-extracts. These formulations may serve as cosmeceuticals to protect skin against injurious effects of UVR. The botanicals studied for dermatologic use in cream form include Acacia nilotica, Benincasa hispida, Calendula officinalis, Camellia sinensis, Camellia sinensis, Nelumbo nucifera, Capparis decidua, Castanea sativa, Coffea arabica, Crocus sativus, Emblica officinalis Gaertn, Foeniculum vulgare, Hippophae rhamnoides, Lithospermum erythrorhizon, Malus domestica, Matricaria chamomilla L., Moringa oleifera, Morus alba, Ocimum basilicum, Oryza sativa, Polygonum minus, Punica granatum, Silybum marianum, Tagetes erecta Linn., Terminalia chebula, Trigonella foenum-graecum, and Vitis vinifera. The observed anti-aging effects of cream formulations could be an outcome of a coordinating action of multiple constituents. Of numerous botanicals, the phenolic acids and flavonoids appear effective against UVR-induced damage; however the evidence-based studies for their anti-aging effects are still needed. PMID:26448818

Consistency of the Proteome in Primary Human Keratinocytes With Respect to Gender, Age, and Skin Localization*

PubMed Central

Sprenger, Adrian; Weber, Sebastian; Zarai, Mostafa; Engelke, Rudolf; Nascimento, Juliana M.; Gretzmeier, Christine; Hilpert, Martin; Boerries, Melanie; Has, Cristina; Busch, Hauke; Bruckner-Tuderman, Leena; Dengjel, Jörn

2013-01-01

Keratinocytes account for 95% of all cells of the epidermis, the stratified squamous epithelium forming the outer layer of the skin, in which a significant number of skin diseases takes root. Immortalized keratinocyte cell lines are often used as research model systems providing standardized, reproducible, and homogenous biological material. Apart from that, primary human keratinocytes are frequently used for medical studies because the skin provides an important route for drug administration and is readily accessible for biopsies. However, comparability of these cell systems is not known. Cell lines may undergo phenotypic shifts and may differ from the in vivo situation in important aspects. Primary cells, on the other hand, may vary in biological functions depending on gender and age of the donor and localization of the biopsy specimen. Here we employed metabolic labeling in combination with quantitative mass spectrometry-based proteomics to assess A431 and HaCaT cell lines for their suitability as model systems. Compared with cell lines, comprehensive profiling of the primary human keratinocyte proteome with respect to gender, age, and skin localization identified an unexpected high proteomic consistency. The data were analyzed by an improved ontology enrichment analysis workflow designed for the study of global proteomics experiments. It enables a quick, comprehensive and unbiased overview of altered biological phenomena and links experimental data to literature. We guide through our workflow, point out its advantages compared with other methods and apply it to visualize differences of cell lines compared with primary human keratinocytes. PMID:23722187

Nutraceuticals for Skin Care: A Comprehensive Review of Human Clinical Studies

PubMed Central

Pérez-Sánchez, Almudena; Micol, Vicente

2018-01-01

The skin is the body’s largest organ, it participates in sensitivity and offers protection against microorganisms, chemicals and ultraviolet (UV) radiation. Consequently, the skin may suffer alterations such as photo-ageing, immune dysfunction and inflammation which may significantly affect human health. Nutraceuticals represent a promising strategy for preventing, delaying, or minimising premature ageing of the skin and also to alleviate certain skin disorders. Among them, bioactive peptides and oligosaccharides, plant polyphenols, carotenoids, vitamins and polyunsaturated fatty acids are the most widely used ingredients. Supplementation with these products has shown evidence of having an effect on the signs of ageing and protection against UV radiation ageing in several human trials. In this review, the most relevant human studies on skin nutraceuticals are evaluated and the statistical resolution, biological relevance of their results, and, the trial protocols are discussed. In conclusion, quality and rigorousness of the trials must be improved to build credible scientific evidence for skin nutraceuticals and to establish a cause-effect relationship between the ingredients the beneficial effects for the skin. PMID:29587342

Nutraceuticals for Skin Care: A Comprehensive Review of Human Clinical Studies.

PubMed

Pérez-Sánchez, Almudena; Barrajón-Catalán, Enrique; Herranz-López, María; Micol, Vicente

2018-03-24

The skin is the body's largest organ, it participates in sensitivity and offers protection against microorganisms, chemicals and ultraviolet (UV) radiation. Consequently, the skin may suffer alterations such as photo-ageing, immune dysfunction and inflammation which may significantly affect human health. Nutraceuticals represent a promising strategy for preventing, delaying, or minimising premature ageing of the skin and also to alleviate certain skin disorders. Among them, bioactive peptides and oligosaccharides, plant polyphenols, carotenoids, vitamins and polyunsaturated fatty acids are the most widely used ingredients. Supplementation with these products has shown evidence of having an effect on the signs of ageing and protection against UV radiation ageing in several human trials. In this review, the most relevant human studies on skin nutraceuticals are evaluated and the statistical resolution, biological relevance of their results, and, the trial protocols are discussed. In conclusion, quality and rigorousness of the trials must be improved to build credible scientific evidence for skin nutraceuticals and to establish a cause-effect relationship between the ingredients the beneficial effects for the skin.

Evaluation and recognition of skin images with aging by support vector machine

NASA Astrophysics Data System (ADS)

Hu, Liangjun; Wu, Shulian; Li, Hui

2016-10-01

Aging is a very important issue not only in dermatology, but also cosmetic science. Cutaneous aging involves both chronological and photoaging aging process. The evaluation and classification of aging is an important issue with the medical cosmetology workers nowadays. The purpose of this study is to assess chronological-age-related and photo-age-related of human skin. The texture features of skin surface skin, such as coarseness, contrast were analyzed by Fourier transform and Tamura. And the aim of it is to detect the object hidden in the skin texture in difference aging skin. Then, Support vector machine was applied to train the texture feature. The different age's states were distinguished by the support vector machine (SVM) classifier. The results help us to further understand the mechanism of different aging skin from texture feature and help us to distinguish the different aging states.

Human skin surface evaluation by image processing

NASA Astrophysics Data System (ADS)

Zhu, Liangen; Zhan, Xuemin; Xie, Fengying

2003-12-01

Human skin gradually lose its tension and becomes very dry as time flies by. Use of cosmetics is effective to prevent skin aging. Recently, there are many choices of products of cosmetics. To show their effects, It is desirable to develop a way to evaluate quantificationally skin surface condition. In this paper, An automatic skin evaluating method is proposed. The skin surface has the pattern called grid-texture. This pattern is composed of the valleys that spread vertically, horizontally, and obliquely and the hills separated by them. Changes of the grid are closely linked to the skin surface condition. They can serve as a good indicator for the skin condition. By measuring the skin grid using digital image processing technologies, we can evaluate skin surface about its aging, health, and alimentary status. In this method, the skin grid is first detected to form a closed net. Then, some skin parameters such as Roughness, tension, scale and gloss can be calculated from the statistical measurements of the net. Through analyzing these parameters, the condition of the skin can be monitored.

Ketorolac alters blood flow during normothermia but not during hyperthermia in middle-aged human skin

PubMed Central

Jennings, John D.; Lang, James A.; Kenney, W. Larry

2009-01-01

In young healthy humans full expression of reflex cutaneous vasodilation is dependent on cyclooxygenase (COX)- and nitric oxide synthase (NOS)-dependent mechanisms. Chronic low-dose aspirin therapy attenuates reflex cutaneous vasodilation potentially through both platelet and vascular COX-dependent mechanisms. We hypothesized the contribution of COX-dependent vasodilators to reflex cutaneous vasodilation during localized acute COX inhibition would be attenuated in healthy middle-aged humans due to a shift toward COX-dependent vasoconstrictors. Four microdialysis fibers were placed in forearm skin of 13 middle-aged (53 ± 2 yr) normotensive healthy humans, serving as control (Ringer), COX-inhibited (10 mM ketorolac), NOS-inhibited (10 mM NG-nitro-l-arginine methyl ester), and combined NOS- and COX-inhibited sites. Red blood cell flux was measured over each site by laser-Doppler flowmetry as reflex vasodilation was induced by increasing oral temperature (Tor) 1.0°C using a water-perfused suit. Cutaneous vascular conductance was calculated (CVC = flux/mean arterial pressure) and normalized to maximal CVC (CVCmax; 28 mM sodium nitroprusside). CVCmax was not affected by localized microdialysis drug treatment (P > 0.05). Localized COX inhibition increased baseline (18 ± 3%CVCmax; P < 0.001) compared with control (9 ± 1%CVCmax), NOS-inhibited (7 ± 1%CVCmax), and combined sites (10 ± 1%CVCmax). %CVCmax in the COX-inhibited site remained greater than the control site with ΔTor ≤ 0.3°C; however, there was no difference between these sites with ΔTor ≥ 0.4°C. NOS inhibition and combined COX and NOS inhibition attenuated reflex vasodilation compared with control (P < 0.001), but there was no difference between these sites. Localized COX inhibition with ketorolac significantly augments baseline CVC but does not alter the subsequent skin blood flow response to hyperthermia, suggesting a limited role for COX-derived vasodilator prostanoids in reflex cutaneous

[Study on objectively evaluating skin aging according to areas of skin texture].

PubMed

Shan, Gaixin; Gan, Ping; He, Ling; Sun, Lu; Li, Qiannan; Jiang, Zheng; He, Xiangqian

2015-02-01

Skin aging principles play important roles in skin disease diagnosis, the evaluation of skin cosmetic effect, forensic identification and age identification in sports competition, etc. This paper proposes a new method to evaluate the skin aging objectively and quantitatively by skin texture area. Firstly, the enlarged skin image was acquired. Then, the skin texture image was segmented by using the iterative threshold method, and the skin ridge image was extracted according to the watershed algorithm. Finally, the skin ridge areas of the skin texture were extracted. The experiment data showed that the average areas of skin ridges, of both men and women, had a good correlation with age (the correlation coefficient r of male was 0.938, and the correlation coefficient r of female was 0.922), and skin texture area and age regression curve showed that the skin texture area increased with age. Therefore, it is effective to evaluate skin aging objectively by the new method presented in this paper.

Aging Differences in Ethnic Skin

PubMed Central

Buainain De Castro Maymone, Mayra; Kundu, Roopal V.

2016-01-01

Aging is an inevitable and complex process that can be described clinically as features of wrinkles, sunspots, uneven skin color, and sagging skin. These cutaneous effects are influenced by both intrinsic and extrinsic factors and often are varied based on ethnic origin given underlying structural and functional differences. The authors sought to provide updated information on facets of aging and how it relates to ethnic variation given innate differences in skin structure and function. Publications describing structural and functional principles of ethnic and aging skin were primarily found through a PubMed literature search and supplemented with a review of textbook chapters. The most common signs of skin aging despite skin type are dark spots, loss of elasticity, loss of volume, and rhytides. Skin of color has many characteristics that make its aging process unique. Those of Asian, Hispanic, and African American descent have distinct facial structures. Differences in the concentration of epidermal melanin makes darkly pigmented persons more vulnerable to dyspigmentation, while a thicker and more compact dermis makes facial lines less noticeable. Ethnic skin comprises a large portion of the world population. Therefore, it is important to understand the unique structural and functional differences among ethnicities to adequately treat the signs of aging. PMID:26962390

Age-related changes in the proteoglycans of human skin. Specific cleavage of decorin to yield a major catabolic fragment in adult skin.

PubMed

Carrino, David A; Onnerfjord, Patrik; Sandy, John D; Cs-Szabo, Gabriella; Scott, Paul G; Sorrell, J Michael; Heinegård, Dick; Caplan, Arnold I

2003-05-09

Dramatic changes occur in skin as a function of age, including changes in morphology, physiology, and mechanical properties. Changes in extracellular matrix molecules also occur, and these changes likely contribute to the overall age-related changes in the physical properties of skin. The major proteoglycans detected in extracts of human skin are decorin and versican. In addition, adult human skin contains a truncated form of decorin, whereas fetal skin contains virtually undetectable levels of this truncated decorin. Analysis of this molecule, herein referred to as decorunt, indicates that it is a catabolic fragment of decorin rather than a splice variant. With antibody probes to the core protein, decorunt is found to lack the carboxyl-terminal portion of decorin. Further analysis by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry shows that the carboxyl terminus of decorunt is at Phe(170) of decorin. This result indicates that decorunt represents the amino-terminal 43% of the mature decorin molecule. Such a structure is inconsistent with alternative splicing of decorin and suggests that decorunt is a catabolic fragment of decorin. A neoepitope antiserum, anti-VRKVTF, was generated against the carboxyl terminus of decorunt. This antiserum does not recognize intact decorin in any skin proteoglycan sample tested on immunoblots but recognizes every sample of decorunt tested. The results with anti-VRKVTF confirm the identification of the carboxyl terminus of decorunt. Analysis of collagen binding by surface plasmon resonance indicates that the affinity of decorunt for type I collagen is 100-fold less than that of decorin. This observation correlates with the structural analysis of decorunt, in that it lacks regions of decorin previously shown to be important for interaction with type I collagen. The detection of a catabolic fragment of decorin suggests the existence of a specific catabolic pathway for this proteoglycan. Because of the

Ex vivo human skin evaluation of localized fat reduction and anti-aging effect by TriPollar radio frequency treatments.

PubMed

Boisnic, Sylvie; Branchet, Marie Christine

2010-02-01

A wide variety of radio frequency (RF) treatments for localized fat and cellulite reduction as well as anti-aging are available nowadays, but only a few have shown the biological mechanism responsible for the clinical results. To determine the biological mechanism of the TriPollar RF device for localized fat and cellulite reduction as well as the collagen remodeling effect. Human skin samples were collected from abdominoplasty surgery and facial lifts, in order to evaluate the lipolytic and anti-aging effects of the apollo device powered by TriPollar RF technology using an ex vivo human skin model. The anti-cellulite effect was evaluated by the dosage of released glycerol and histological analysis of the hypodermis. Skin tightening was evaluated by morphometric analysis of collagen fibers and the dosage of collagen synthesis. Following TriPollar treatment, a significant increase of glycerol release by skin samples was found. The structure of fat cells was altered in shape and a modification of the fibrous tract was also detected in the fat layer. Additional findings indicated stimulation of the dermal fibroblasts with increased collagen synthesis. The detected alteration in the hypodermal layer is manifested by fat and cellulite reduction accompanied by structural and biochemical improvement of dermal collagen, which result in overall skin tightening.

Archaea on Human Skin

PubMed Central

Probst, Alexander J.; Auerbach, Anna K.; Moissl-Eichinger, Christine

2013-01-01

The recent era of exploring the human microbiome has provided valuable information on microbial inhabitants, beneficials and pathogens. Screening efforts based on DNA sequencing identified thousands of bacterial lineages associated with human skin but provided only incomplete and crude information on Archaea. Here, we report for the first time the quantification and visualization of Archaea from human skin. Based on 16 S rRNA gene copies Archaea comprised up to 4.2% of the prokaryotic skin microbiome. Most of the gene signatures analyzed belonged to the Thaumarchaeota, a group of Archaea we also found in hospitals and clean room facilities. The metabolic potential for ammonia oxidation of the skin-associated Archaea was supported by the successful detection of thaumarchaeal amoA genes in human skin samples. However, the activity and possible interaction with human epithelial cells of these associated Archaea remains an open question. Nevertheless, in this study we provide evidence that Archaea are part of the human skin microbiome and discuss their potential for ammonia turnover on human skin. PMID:23776475

Alterations of Dermal Connective Tissue Collagen in Diabetes: Molecular Basis of Aged-Appearing Skin

PubMed Central

Argyropoulos, Angela J.; Robichaud, Patrick; Balimunkwe, Rebecca Mutesi; Fisher, Gary J.; Hammerberg, Craig; Yan, Yan

2016-01-01

Alterations of the collagen, the major structural protein in skin, contribute significantly to human skin connective tissue aging. As aged-appearing skin is more common in diabetes, here we investigated the molecular basis of aged-appearing skin in diabetes. Among all known human matrix metalloproteinases (MMPs), diabetic skin shows elevated levels of MMP-1 and MMP-2. Laser capture microdissection (LCM) coupled real-time PCR indicated that elevated MMPs in diabetic skin were primarily expressed in the dermis. Furthermore, diabetic skin shows increased lysyl oxidase (LOX) expression and higher cross-linked collagens. Atomic force microscopy (AFM) further indicated that collagen fibrils were fragmented/disorganized, and key mechanical properties of traction force and tensile strength were increased in diabetic skin, compared to intact/well-organized collagen fibrils in non-diabetic skin. In in vitro tissue culture system, multiple MMPs including MMP-1 and MM-2 were induced by high glucose (25 mM) exposure to isolated primary human skin dermal fibroblasts, the major cells responsible for collagen homeostasis in skin. The elevation of MMPs and LOX over the years is thought to result in the accumulation of fragmented and cross-linked collagen, and thus impairs dermal collagen structural integrity and mechanical properties in diabetes. Our data partially explain why old-looking skin is more common in diabetic patients. PMID:27104752

Genetic variants associated with skin aging in the Chinese Han population.

PubMed

Gao, Wenshan; Tan, Jingze; Hüls, Anke; Ding, Anan; Liu, Yu; Matsui, Mary S; Vierkötter, Andrea; Krutmann, Jean; Schikowski, Tamara; Jin, Li; Wang, Sijia

2017-04-01

The progression and manifestation of human skin aging has a strong genetic basis; however, most of the supporting evidence has been gathered in Caucasian populations. The genetic contribution to the variation in skin aging in non-Caucasian populations is poorly understood. To investigate the genetic risk factors of relevance for skin aging in East Asians, we conducted the first candidate gene study for signs of skin aging in Han Chinese. We collected skin aging and genotype data in 502 female Han Chinese from the Taizhou cohort. We evaluated skin aging by the validated skin aging score SCINEXA™. Confounding factors were assessed through a questionnaire. We obtained the genotype data for 21 candidate SNPs and for a further 509 SNPs from 16 related candidate genes. Associations were tested by linear and logistic regression analyses and adjusted for potential confounders. Our candidate study found a significant association between SNP rs2066853 in exon 10 of the aryl hydrocarbon receptor gene AHR and crow's feet. In addition, we found a significant association between SNP rs10733310 in intron 5 of BNC2 and pigment spots on the arms, and between SNP rs11979919, 3kb downstream of COL1A2, and laxity of eyelids. Our results identified genetic risk factors for signs of skin aging (pigmentation, wrinkles or laxity) in Han Chinese. We also found that the manifestation of skin aging is further modified by anatomical site. Together with previous work, our results also suggest that different genetic variants could be responsible for distinct skin aging signs characteristic of Caucasians compared to East Asians. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Reflex vasoconstriction in aged human skin increasingly relies on Rho kinase-dependent mechanisms during whole body cooling

PubMed Central

Jennings, John D.; Holowatz, Lacy A.; Kenney, W. Larry

2009-01-01

Primary human aging may be associated with augmented Rho kinase (ROCK)-mediated contraction of vascular smooth muscle and ROCK-mediated inhibition of nitric oxide synthase (NOS). We hypothesized that the contribution of ROCK to reflex vasoconstriction (VC) is greater in aged skin. Cutaneous VC was elicited by 1) whole body cooling [mean skin temperature (Tsk) = 30.5°C] and 2) local norepinephrine (NE) infusion (1 × 10−6 M). Four microdialysis fibers were placed in the forearm skin of eight young (Y) and eight older (O) subjects for infusion of 1) Ringer solution (control), 2) 3 mM fasudil (ROCK inhibition), 3) 20 mM NG-nitro-l-arginine methyl ester (NOS inhibition), and 4) both ROCK + NOS inhibitors. Red cell flux was measured by laser-Doppler flowmetry over each site. Cutaneous vascular conductance (CVC) was calculated as flux/mean arterial pressure and normalized to baseline CVC (%ΔCVCbaseline). VC was reduced at the control site in O during cooling (Y, −34 ± 3; and O, −18 ± 3%ΔCVCbaseline; P < 0.001) and NE infusion (Y, −53 ± 4, and O, −41 ± 9%ΔCVCbaseline; P = 0.006). Fasudil attenuated VC in both age groups during mild cooling; however, this reduction remained only in O but not in Y skin during moderate cooling (Y, −30 ± 5; and O, −7 ± 1%ΔCVCbaseline; P = 0.016) and was not altered by NOS inhibition. Fasudil blunted NE-mediated VC in both age groups (Y, −23 ± 4; and O, −7 ± 3%ΔCVCbaseline; P < 0.01). Cumulatively, these data indicate that reflex VC is more reliant on ROCK in aged skin such that approximately half of the total VC response to whole body cooling is ROCK dependent. PMID:19717729

Langerhans cell precursors acquire RANK/CD265 in prenatal human skin

PubMed Central

Schöppl, Alice; Botta, Albert; Prior, Marion; Akgün, Johnnie; Schuster, Christopher; Elbe-Bürger, Adelheid

2015-01-01

The skin is the first barrier against foreign pathogens and the prenatal formation of a strong network of various innate and adaptive cells is required to protect the newborn from perinatal infections. While many studies about the immune system in healthy and diseased adult human skin exist, our knowledge about the cutaneous prenatal/developing immune system and especially about the phenotype and function of antigen-presenting cells such as epidermal Langerhans cells (LCs) in human skin is still scarce. It has been shown previously that LCs in healthy adult human skin express receptor activator of NF-κB (RANK), an important molecule prolonging their survival. In this study, we investigated at which developmental stage LCs acquire this important molecule. Immunofluorescence double-labeling of cryostat sections revealed that LC precursors in prenatal human skin either do not yet [10–11 weeks of estimated gestational age (EGA)] or only faintly (13–15 weeks EGA) express RANK. LCs express RANK at levels comparable to adult LCs by the end of the second trimester. Comparable with adult skin, dermal antigen-presenting cells at no gestational age express this marker. These findings indicate that epidermal leukocytes gradually acquire RANK during gestation – a phenomenon previously observed also for other markers on LCs in prenatal human skin. PMID:25722033

Age-related differences in morphological characteristics of residual skin surface components collected from the surface of facial skin of healthy male volunteers.

PubMed

Chalyk, N E; Bandaletova, T Y; Kyle, N H; Petyaev, I M

2017-05-01

Global increase of human longevity results in the emergence of previously ignored ageing-related problems. Skin ageing is a well-known phenomenon, but active search for scientific approaches to its prevention and even skin rejuvenation is a relatively new area. Although the structure and composition of the stratum corneum (SC), the superficial layer of epidermis, is well studied, relatively little is known about the residual skin surface components (RSSC) that overlay the surface of the SC. The aim of this study was to examine morphological features of RSSC samples non-invasively collected from the surface of human facial skin for the presence of age-related changes. Residual skin surface component samples were collected by swabbing from the surface of facial skin of 60 adult male volunteers allocated in two age groups: 34 subjects aged in the range 18-32 years and 26 subjects aged in the range 58-72 years. The collected samples were analysed microscopically: the size of the lipid droplets was measured; desquamated corneocytes and lipid crystals were counted; and microbial presence was assessed semi-quantitatively. Age-related changes were revealed for all studied components of the RSSC. There was a significant (P = 0.0126) decrease in the size of lipid droplets among older men. Likewise, significantly (P = 0.0252) lower numbers of lipid crystals were present in this group. In contrast, microbial presence in the RSSC was significantly (P = 0.0019) increased in the older group. There was also a trend towards more abundant corneocyte desquamation among older men, but the difference has not reached statistical significance (P = 0.0636). Non-invasively collected RSSC samples present an informative material for studying age-related changes on the surface of the SC of human facial skin. The results of this study confirm earlier observations regarding age-associated decline of the efficiency of the epidermal barrier and can be used for testing new approaches to skin

Skin Diseases: Cross-section of human skin

MedlinePlus

Skip Navigation Bar Home Current Issue Past Issues Skin Diseases Cross-section of human skin Past Issues / Fall 2008 Table of Contents For ... Logical Images, Inc. I n the areas of skin health and skin diseases, the NIH's National Institute ...

Novel effects of diosgenin on skin aging.

PubMed

Tada, Yayoi; Kanda, Naoko; Haratake, Akinori; Tobiishi, Megumi; Uchiwa, Hideyo; Watanabe, Shinichi

2009-06-01

Extracts of Dioscorea coomposita or Dioscorea villosa are consumed as supplemental health foods at the time of climacteric. The extracts contain large amounts of the plant steroid, diosgenin. Here, we studied the safety and efficacy of diosgenin against skin aging at the time of climacteric. In vitro, diosgenin enhanced DNA synthesis in a human 3D skin equivalent model, and increased bromodeoxyuridine uptake and intracellular cAMP level in adult human keratinocytes. The increase of bromodeoxyuridine uptake by diosgenin was blocked by an adenylate cyclase inhibitor, but not by antisense oligonucleotides against estrogen receptor alpha, estrogen receptor beta or an orphan G-protein-coupled receptor, GPR30, indicating the involvement of cAMP but not estrogen receptor alpha, estrogen receptor beta or GPR30. In vivo, administration of diosgenin improved the epidermal thickness in the ovariectomized mice, a climacteric model, without altering the degree of fat accumulation. In order to examine the safety of diosgenin, diosgenin and 17beta-estradiol were administered to breast cancer-burdened mice. The results revealed that while 17beta-estradiol accelerated the tumor growth, diosgenin did not show this effect. Our finding, a restoration of keratinocyte proliferation in aged skin, suggests that diosgenin may have potential as a safe health food for climacteric.

Skin aging by glycation: lessons from the reconstructed skin model.

PubMed

Pageon, Hervé; Zucchi, Hélène; Rousset, Françoise; Monnier, Vincent M; Asselineau, Daniel

2014-01-01

Aging is the result of several mechanisms which operate simultaneously. Among them, glycation is of particular interest because it is a reaction which affects slowly renewing tissues and macromolecules with elevated half-life, like the dermis, a skin compartment highly affected by aging. Glycation produces crosslinks between macromolecules thereby providing an explanation for the increased age-related stiffness of the skin. Glycation products, also called AGEs (advanced glycation end products), accumulate primarily in extracellular matrix molecules like collagen or elastin. In order to reproduce this phenomenon in vitro we have created a model of reconstructed skin modified by glycation of the collagen used to fabricate the dermal compartment. This system allowed us to uncover biological modifications of dermal markers, and more surprisingly epidermal markers, as well as an increase of metalloproteinases responsible for degradation of the dermal matrix. Consequently, the imbalance between synthesis and degradation that results from glycation, may contribute to skin aging, as shown in this model. Moreover these modifications were shown to be prevented by the addition of aminoguanidine, a well-known inhibitor of glycation. Using this experimental approach our results taken together stress the importance and possibly central role of glycation in skin aging and the usefulness of the reconstructed skin as a model of physiological aging.

[Ultraviolet radiation, tobacco smoke and estrogens pathways of influence on skin aging; capabilities of prevention].

PubMed

Wojas-Pelc, Anna; Sułowicz, Joanna; Nastałek, Magdalena

2008-01-01

Aging refers to the hole human body including the skin, but here it is usually better seen by milieu, repeatedly burdens life quality. There are many theories explaining the process of human aging, but its reasons, irrespectively of their criteria, are numerous and affect one another. Skin aging just like the entire body depends on the influence of genetics, environmental and hormonal factors. Ultraviolet radiation and tobacco smoking have confirmed influence on skin aging. The role of hormonal disorders, particularly estrogens are also underlined. Mechanisms of skin aging induced by UV radiation, tobacco smoke and estrogens are similar and included unfavourable effects of oxidative stress (free radicals) and also disturbances of the TGF beta pathway. Data of many clinical studies proved that avoiding sun and smoking, nucleic acids diet, antioxidant supplementation, everyday use of UV filter, moisturizers, topical use of antioxidants, retinoid derivatives and flavonoids have proved protective the influence to multidirectional process of skin aging.

Measuring skin aging using optical coherence tomography in vivo: a validation study

NASA Astrophysics Data System (ADS)

Trojahn, Carina; Dobos, Gabor; Richter, Claudia; Blume-Peytavi, Ulrike; Kottner, Jan

2015-04-01

Dermal and epidermal structures in human skin change during intrinsic and extrinsic aging. Epidermal thickness is one of the most often reported parameters for the assessment of skin aging in cross-sectional images captured by optical coherence tomography (OCT). We aimed to identify further parameters for the noninvasive measurement of skin aging of sun-exposed and sun-protected areas utilizing OCT. Based on a literature review, seven parameters were inductively developed. Three independent raters assessed these parameters using four-point scales on images of female subjects of two age groups. All items could be detected and quantified in our sample. Interrater agreement ranged between 25.0% and 83.3%. The item scores "stratum corneum reflectivity," "upper dermal reflectivity," and "dermoepidermal contrast" showed significant differences between age groups on the volar and dorsal forearm indicating that they were best able to measure changes during skin aging. "Surface unevenness" was associated with the skin roughness parameters, Rz and Rmax, on the inner upper arm and volar forearm supporting the criterion validity of this parameter on sun-protected skin areas. Based on the interrater agreement and the ability to differentiate between age groups, these four parameters are being considered as the best candidates for measuring skin aging in OCT images.

Measuring skin aging using optical coherence tomography in vivo: a validation study.

PubMed

Trojahn, Carina; Dobos, Gabor; Richter, Claudia; Blume-Peytavi, Ulrike; Kottner, Jan

2015-04-01

Dermal and epidermal structures in human skin change during intrinsic and extrinsic aging. Epidermal thickness is one of the most often reported parameters for the assessment of skin aging in cross-sectional images captured by optical coherence tomography (OCT). We aimed to identify further parameters for the noninvasive measurement of skin aging of sun-exposed and sun-protected areas utilizing OCT. Based on a literature review, seven parameters were inductively developed. Three independent raters assessed these parameters using four-point scales on images of female subjects of two age groups. All items could be detected and quantified in our sample. Interrater agreement ranged between 25.0% and 83.3%. The item scores “stratum corneum reflectivity,” “upper dermal reflectivity,” and “dermoepidermal contrast” showed significant differences between age groups on the volar and dorsal forearm indicating that they were best able to measure changes during skin aging. “Surface unevenness” was associated with the skin roughness parameters, Rz and Rmax, on the inner upper arm and volar forearm supporting the criterion validity of this parameter on sun-protected skin areas. Based on the interrater agreement and the ability to differentiate between age groups, these four parameters are being considered as the best candidates for measuring skin aging in OCT images.

Langerhans cell precursors acquire RANK/CD265 in prenatal human skin.

PubMed

Schöppl, Alice; Botta, Albert; Prior, Marion; Akgün, Johnnie; Schuster, Christopher; Elbe-Bürger, Adelheid

2015-01-01

The skin is the first barrier against foreign pathogens and the prenatal formation of a strong network of various innate and adaptive cells is required to protect the newborn from perinatal infections. While many studies about the immune system in healthy and diseased adult human skin exist, our knowledge about the cutaneous prenatal/developing immune system and especially about the phenotype and function of antigen-presenting cells such as epidermal Langerhans cells (LCs) in human skin is still scarce. It has been shown previously that LCs in healthy adult human skin express receptor activator of NF-κB (RANK), an important molecule prolonging their survival. In this study, we investigated at which developmental stage LCs acquire this important molecule. Immunofluorescence double-labeling of cryostat sections revealed that LC precursors in prenatal human skin either do not yet [10-11 weeks of estimated gestational age (EGA)] or only faintly (13-15 weeks EGA) express RANK. LCs express RANK at levels comparable to adult LCs by the end of the second trimester. Comparable with adult skin, dermal antigen-presenting cells at no gestational age express this marker. These findings indicate that epidermal leukocytes gradually acquire RANK during gestation - a phenomenon previously observed also for other markers on LCs in prenatal human skin. Copyright © 2015 The Authors. Published by Elsevier GmbH.. All rights reserved.

P16INK4a Positive Cells in Human Skin Are Indicative of Local Elastic Fiber Morphology, Facial Wrinkling, and Perceived Age

PubMed Central

Waaijer, Mariëtte E. C.; Gunn, David A.; Adams, Peter D.; Pawlikowski, Jeff S.; Griffiths, Christopher E. M.; van Heemst, Diana; Slagboom, P. Eline; Westendorp, Rudi G. J.; Maier, Andrea B.

2016-01-01

Senescent cells are more prevalent in aged human skin compared to young, but evidence that senescent cells are linked to other biomarkers of aging is scarce. We counted cells positive for the tumor suppressor and senescence associated protein p16INK4a in sun-protected upper-inner arm skin biopsies from 178 participants (aged 45–81 years) of the Leiden Longevity Study. Local elastic fiber morphology, facial wrinkles, and perceived facial age were compared to tertiles of p16INK4a counts, while adjusting for chronological age and other potential confounders. The numbers of epidermal and dermal p16INK4a positive cells were significantly associated with age-associated elastic fiber morphologic characteristics, such as longer and a greater number of elastic fibers. The p16INK4a positive epidermal cells (identified as primarily melanocytes) were also significantly associated with more facial wrinkles and a higher perceived age. Participants in the lowest tertile of epidermal p16INK4a counts looked 3 years younger than those in the highest tertile, independently of chronological age and elastic fiber morphology. In conclusion, p16INK4a positive cell numbers in sun-protected human arm skin are indicative of both local elastic fiber morphology and the extent of aging visible in the face. PMID:26286607

Aging Alters Functionally Human Dermal Papillary Fibroblasts but Not Reticular Fibroblasts: A New View of Skin Morphogenesis and Aging

PubMed Central

Mine, Solène; Fortunel, Nicolas O.; Pageon, Hervé; Asselineau, Daniel

2008-01-01

Understanding the contribution of the dermis in skin aging is a key question, since this tissue is particularly important for skin integrity, and because its properties can affect the epidermis. Characteristics of matched pairs of dermal papillary and reticular fibroblasts (Fp and Fr) were investigated throughout aging, comparing morphology, secretion of cytokines, MMPs/TIMPs, growth potential, and interaction with epidermal keratinocytes. We observed that Fp populations were characterized by a higher proportion of small cells with low granularity and a higher growth potential than Fr populations. However, these differences became less marked with increasing age of donors. Aging was also associated with changes in the secretion activity of both Fp and Fr. Using a reconstructed skin model, we evidenced that Fp and Fr cells do not possess equivalent capacities to sustain keratinopoiesis. Comparing Fp and Fr from young donors, we noticed that dermal equivalents containing Fp were more potent to promote epidermal morphogenesis than those containing Fr. These data emphasize the complexity of dermal fibroblast biology and document the specific functional properties of Fp and Fr. Our results suggest a new model of skin aging in which marked alterations of Fp may affect the histological characteristics of skin. PMID:19115004

Atmospheric skin aging-Contributors and inhibitors.

PubMed

McDaniel, David; Farris, Patricia; Valacchi, Giuseppe

2018-04-01

Cutaneous aging is a complex biological process consisting of 2 elements: intrinsic aging, which is primarily determined by genetics, and extrinsic aging, which is largely caused by atmospheric factors, such as exposure to sunlight and air pollution, and lifestyle choices, such as diet and smoking. The role of the solar spectrum, comprised of ultraviolet light, specifically UVB (290-320 nm) and UVA (320-400) in causing skin damage, including skin cancers, has been well documented. In recent years, the contribution of visible light (400-700 nm) and infrared radiation (above 800 nm) in causing skin damage, similar to the photodamage caused by UV light, is also being elucidated. In addition, other atmospheric factors such as air pollution (smog, ozone, particulate matter, etc.) have been implicated in premature skin aging. The skin damage caused by environmental exposure is largely attributable to a complex cascade of reactions inside the skin initiated by the generation of reactive oxygen species (ROS), which causes oxidative damage to cellular components such as proteins, lipids, and nucleic acids. These damaged skin cells initiate inflammatory responses leading to the eventual damage manifested in chronically exposed skin. Novel therapeutic strategies to combat ROS species generation are being developed to prevent the skin damage caused by atmospheric factors. In addition to protecting skin from solar radiation using sunscreens, other approaches using topically applied ingredients, particularly antioxidants that penetrate the skin and protect the skin from within, have also been well documented. This review summarizes current knowledge of atmospheric aggressors, including UVA, UVB, visible light, infrared radiation (IR), and ozone on skin damage, and proposes new avenues for future research in the prevention and treatment of premature skin aging caused by such atmospheric factors. New therapeutic modalities currently being developed are also discussed. © 2018

The Microbiota of the Human Skin.

PubMed

Egert, Markus; Simmering, Rainer

2016-01-01

The aim of this chapter is to sum up important progress in the field of human skin microbiota research that was achieved over the last years.The human skin is one of the largest and most versatile organs of the human body. Owing to its function as a protective interface between the largely sterile interior of the human body and the highly microbially contaminated outer environment, it is densely colonized with a diverse and active microbiota. This skin microbiota is of high importance for human health and well-being. It is implicated in several severe skin diseases and plays a major role in wound infections. Many less severe, but negatively perceived cosmetic skin phenomena are linked with skin microbes, too. In addition, skin microorganisms, in particular on the human hands, are crucial for the field of hygiene research. Notably, apart from being only a potential source of disease and contamination, the skin microbiota also contributes to the protective functions of the human skin in many ways. Finally, the analysis of structure and function of the human skin microbiota is interesting from a basic, evolutionary perspective on human microbe interactions.Key questions in the field of skin microbiota research deal with (a) a deeper understanding of the structure (species inventory) and function (physiology) of the healthy human skin microbiota in space and time, (b) the distinction of resident and transient skin microbiota members, (c) the distinction of beneficial skin microorganisms from microorganisms or communities with an adverse or sickening effect on their hosts, (d) factors shaping the skin microbiota and its functional role in health and disease, (e) strategies to manipulate the skin microbiota for therapeutic reasons.

An evaluation of the effect of a topical product containing salicin on the visible signs of human skin aging.

PubMed

Gopaul, Remona; Knaggs, Helen E; Lephart, Janet F; Holley, Kara C; Gibson, Erica M

2010-09-01

There are many different visible signs of skin aging. These include wrinkles, hyperpigmentation, lack of firmness, poor texture, enlarged pores, and dryness. While there are many topical agents that claim to deliver wide-spectrum anti-aging benefits, few target all of the signs of skin aging to the same extent. Salicin, an extract from white willow bark, has been researched as a potent anti-inflammatory agent when taken orally. Based on unpublished in-house comprehensive consumer clinical studies, it is believed salicin may have anti-aging capabilities when applied topically to human skin. This research evaluated the effect of a topical serum formulation containing salicin at 0.5% on the visible signs of skin aging. This single-center study enrolled 30 female subjects, showing mild to moderate signs of aging, between the ages of 35 and 70 having Fitzpatrick skin types ranging between I and IV. Subjects used the study serum product containing 0.5% salicin on their face twice daily for 12 weeks. Ordinal grading on a nine-point scale (0 = none, 1-3 = mild, 4-6 = moderate, 7-9 = severe) of facial fine lines, molted pigmentation, uneven skin tone, tactile roughness, global firmness appearance, jaw-line contour, radiance, and overall appearance was performed by investigator at baseline, week 1, week 4, week 8, and week 12. Digital photography, ultrasound, cutometry, and corneometry measurements were also performed at each time point. Twenty-nine of 30 subjects successfully completed the study. No tolerability issues were reported. The clinical investigator found statistically significant improvements in wrinkles, tactile roughness, pore size, radiance, and overall appearance at week 1 time point (P ≤ 0.05) against baseline and statistically significant improvements in mottled pigmentation, global firmness, and jaw-line contour at week 4 time point (P ≤ 0.05) against baseline. Cutometry, corneometry, and ultrasound measurements showed significant improvements at week

In vivo observation of age-related structural changes of dermal collagen in human facial skin using collagen-sensitive second harmonic generation microscope equipped with 1250-nm mode-locked Cr:Forsterite laser

NASA Astrophysics Data System (ADS)

Yasui, Takeshi; Yonetsu, Makoto; Tanaka, Ryosuke; Tanaka, Yuji; Fukushima, Shu-ichiro; Yamashita, Toyonobu; Ogura, Yuki; Hirao, Tetsuji; Murota, Hiroyuki; Araki, Tsutomu

2013-03-01

In vivo visualization of human skin aging is demonstrated using a Cr:Forsterite (Cr:F) laser-based, collagen-sensitive second harmonic generation (SHG) microscope. The deep penetration into human skin, as well as the specific sensitivity to collagen molecules, achieved by this microscope enables us to clearly visualize age-related structural changes of collagen fiber in the reticular dermis. Here we investigated intrinsic aging and/or photoaging in the male facial skin. Young subjects show dense distributions of thin collagen fibers, whereas elderly subjects show coarse distributions of thick collagen fibers. Furthermore, a comparison of SHG images between young and elderly subjects with and without a recent life history of excessive sun exposure show that a combination of photoaging with intrinsic aging significantly accelerates skin aging. We also perform image analysis based on two-dimensional Fourier transformation of the SHG images and extracted an aging parameter for human skin. The in vivo collagen-sensitive SHG microscope will be a powerful tool in fields such as cosmeceutical sciences and anti-aging dermatology.

Could tight junctions regulate the barrier function of the aged skin?

PubMed

Svoboda, Marek; Bílková, Zuzana; Muthný, Tomáš

2016-03-01

The skin is known to be the largest organ in human organism creating interface with outer environment. The skin provides protective barrier against pathogens, physical and chemical insults, and against uncontrolled loss of water. The barrier function was primarily attributed to the stratum corneum (SC) but recent studies confirmed that epidermal tight junctions (TJs) also play important role in maintaining barrier properties of the skin. Independent observations indicate that barrier function and its recovery is impaired in aged skin. However, trans-epidermal water loss (TEWL) values remains rather unchanged in elderly population. UV radiation as major factor of photoageing impairs TJ proteins, but TJs have great self-regenerative potential. Since it may be possible that TJs can compensate TEWL in elderly due to its regenerative and compensatory capabilities, important question remains to be answered: how are TJs regulated during skin ageing? This review provides an insight into TJs functioning as epidermal barrier and summarizes current knowledge about the impact of ageing on the barrier function of the skin and epidermal TJs. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Beneficial modulation from a high-purity caviar-derived homogenate on chronological skin aging.

PubMed

Marotta, Francesco; Polimeni, Ascanio; Solimene, Umberto; Lorenzetti, Aldo; Minelli, Emilio; Jain, Shalini; Rastmanesh, Reza; Sedriep, Sonia; Soresi, Vincenzo

2012-04-01

This study tested the activity of LD-1227, which contains a caviar-derived homogenate added with coenzyme Q(10) (CoQ(10))-selenium component (CaviarLieri(®), Lab-Dom, Switzerland), in aged human skin and its potential role on skin mitochondria function. Human dermal fibroblasts were obtained from healthy donors over 70 years old and treated with LD-1227 for 72 hr. As compared to baseline, LD-1227 caused a robust (>67%) collagen type I synthesis (p<0.001) and decreased fibronectin synthesis (p<0.05) with significant fibronectin messenger RNA (mRNA) downregulation (p<0.05, r=0.78). A significant collagen mRNA overexpression occurred with LD-1227 treatment (p<0.05). Mitochondria cytosolic adenosine triphosphate (ATP) level decreased in aged skin samples (p<0.05 vs. young control), but this phenomenon was reversed by LD-1227 (p<0.01). These data show that LD-1227 may modify the extracellular matrix milieu in aged skin and also beneficially affect mitochondrial function.

Skin aging as a mechanical phenomenon: The main weak links

PubMed Central

Kruglikov, Ilja L.; Scherer, Philipp E.

2018-01-01

From a mechanical point of view, human skin appears as a layered composite containing the stiff thin cover layer presented by the stratum corneum, below which are the more compliant layers of viable epidermis and dermis and further below the much more compliant adjacent layer of subcutaneous white adipose tissue (sWAT). Upon exposure to a strain, such a multi-layer system demonstrates structural instabilities in its stiffer layers, which in its simplest form is the wrinkling. These instabilities appear hierarchically when the mechanical strain in the skin exceeds some critical values. Their appearance is mainly dependent on the mismatch in mechanical properties between adjacent skin layers or between the skin and sWAT, on the adhesive strength and thickness ratios between the layers, on their bending and tensile stiffness as well as on the value of the stress existing in single layers. Gradual reduction of elastic fibers in aging significantly reduces the skin’s ability to bend, prompting an up to 4-fold reduction of its stability against wrinkling, thereby explaining the role of these fibers in skin aging. While chronological and extrinsic aging differently modify these parameters, they lead to the same end result, reducing the critical strain required for the onset of instabilities. Comparing of mechanical properties of the skin presented as a bi-, tri- or tetra-layer structure demonstrates the particular importance of the papillary dermis in skin aging and provides the arguments to consider the undulations on the dermal-epidermal and dermal-sWAT interfaces as the result of mechanical bifurcation, leading to structural instabilities inside of the skin. According to this model, anti-aging strategies should focus not as much on the reinforcement of the dermis, but rather aim to treat the elastic mismatch between different adjacent layers in the skin and sWAT as well as the adhesion between these layers.

Human skin volatiles: a review.

PubMed

Dormont, Laurent; Bessière, Jean-Marie; Cohuet, Anna

2013-05-01

Odors emitted by human skin are of great interest to biologists in many fields; applications range from forensic studies to diagnostic tools, the design of perfumes and deodorants, and the ecology of blood-sucking insect vectors of human disease. Numerous studies have investigated the chemical composition of skin odors, and various sampling methods have been used for this purpose. The literature shows that the chemical profile of skin volatiles varies greatly among studies, and the use of different sampling procedures is probably responsible for some of these variations. To our knowledge, this is the first review focused on human skin volatile compounds. We detail the different sampling techniques, each with its own set of advantages and disadvantages, which have been used for the collection of skin odors from different parts of the human body. We present the main skin volatile compounds found in these studies, with particular emphasis on the most frequently studied body regions, axillae, hands, and feet. We propose future directions for promising experimental studies on odors from human skin, particularly in relation to the chemical ecology of blood-sucking insects.

Relation between skin micro-topography, roughness, and skin age.

PubMed

Trojahn, C; Dobos, G; Schario, M; Ludriksone, L; Blume-Peytavi, U; Kottner, J

2015-02-01

The topography of the skin surface consists of lines, wrinkles, and scales. Primary and secondary lines form a network like structure that may be identified as polygons. Skin surface roughness measurements are widely applied in dermatological research and practice but the relation between roughness parameters and their anatomical equivalents are unclear. This study aimed to investigate whether the number of closed polygons (NCP) per measurement field can be used as a reliable parameter to measure skin surface topography. For this purpose, we analysed the relation between skin surface roughness parameters and NCP in different age groups. Images of the volar forearm skin of 38 subjects (14 children, 12 younger, and 12 older adults) were obtained with the VisioScan VC98. The NCP was counted by three independent researchers and selected roughness parameters were measured. Interrater reliability of counting the number of closed polygons and correlations between NCP, roughness parameters, and age were calculated. The mean NCP/mm² in children was 3.1 (SD 1.1), in younger adults 1.0 (SD 0.7), and in older adults 1.0 (SD 0.9). The interrater reliability was 0.9. A negative correlation of NCP/mm² with age was observed, whereas measured roughness parameters were positively associated with age. NCP/mm² was weakly related to skin roughness. The NCP/mm² is a reproducible parameter for characterizing the skin surface topography. It is proposed as an additional parameter in dermatological research and practice because it represents distinct aspects of the cutaneous profile not covered by established roughness parameters. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Xenobiotic metabolism in human skin and 3D human skin reconstructs: a review.

PubMed

Gibbs, Sue; van de Sandt, Johannes J M; Merk, Hans F; Lockley, David J; Pendlington, Ruth U; Pease, Camilla K

2007-12-01

In this review, we discuss and compare studies of xenobiotic metabolism in both human skin and 3D human skin reconstructs. In comparison to the liver, the skin is a less studied organ in terms of characterising metabolic capability. While the skin forms the major protective barrier to environmental chemical exposure, it is also a potential target organ for adverse health effects. Occupational, accidental or intended-use exposure to toxic chemicals could result in acute or delayed injury to the skin (e.g. inflammation, allergy, cancer). Skin metabolism may play a role in the manifestation or amelioration of adverse effects via the topical route. Today, we have robust testing strategies to assess the potential for local skin toxicity of chemical exposure. Such methods (e.g. the local lymph node assay for assessing skin sensitisation; skin painting carcinogenicity studies) incorporate skin metabolism implicitly in the in vivo model system used. In light of recent European legislation (i.e. 7(th) Amendment to the Cosmetics Directive and Registration Evaluation and Authorisation of existing Chemicals (REACH)), non-animal approaches will be required to reduce and replace animal experiments for chemical risk assessment. It is expected that new models and approaches will need to account for skin metabolism explicitly, as the mechanisms of adverse effects in the skin are deconvoluted. 3D skin models have been proposed as a tool to use in new in vitro alternative approaches. In order to be able to use 3D skin models in this context, we need to understand their metabolic competency in relation to xenobiotic biotransformation and whether functional activity is representative of that seen in human skin.

Non-invasive, investigative methods in skin aging.

PubMed

Longo, C; Ciardo, S; Pellacani, G

2015-12-01

A precise and noninvasive quantification of aging is of outmost importance for in vivo assessment of the skin aging "stage", and thus acts to minimize it. Several bioengineering methods have been proposed to objectively, precisely, and non-invasively measure skin aging, and to detect early skin damage, that is sub-clinically observable. In this review we have described the most relevant methods that have emerged from recently introduced technologies, aiming at quantitatively assessing the effects of aging on the skin.

Skin texture parameters of the dorsal hand in evaluating skin aging in China.

PubMed

Gao, Qian; Hu, Li-Wen; Wang, Yang; Xu, Wen-Ying; Ouyang, Nan-Ning; Dong, Guo-Qing; Shi, Song-Tian; Liu, Yang

2011-11-01

There are various non-invasive methods in skin morphology for assessing skin aging. The use of digital photography will make it easier and more convenient. In this study, we explored some skin texture parameters for evaluating skin aging using digital image processing. Two hundred and twenty-eight subjects who lived in Sanya, China, were involved. Individual sun exposure history and other factors influencing skin aging were collected by a questionnaire. Meanwhile, we took photos of their dorsal hands. Skin images were graded according to the Beagley-Gibson system. These skin images were also processed using image analysis software. Five skin texture parameters, Angle Num., Angle Max., Angle Diff., Distance and Grids, were produced in reference to the Beagley-Gibson system. All texture parameters were significantly associated with the Beagley-Gibson score. Among the parameters, the distance between primary lines (Distance) and the value of angle formed by intersection textures (Angle Max., Angle Diff.) were positively associated with the Beagley-Gibson score. However, there was a negative correlation between the number of grids (Grids), the number of angle (Angle Num.) and the Beagley-Gibson score. These texture parameters were also correlated with factors influencing skin aging such as sun exposure, age, smoking, drinking and body mass index. In multivariate analysis, Grids and Distance were mainly affected by age. But Angle Max. and Angle Diff. were mainly affected by sun exposure. It seemed that the skin surface morphologic parameters presented in our study reflect skin aging changes to some extent and could be used to describe skin aging using digital image processing. © 2011 John Wiley & Sons A/S.

Resveratrol-Enriched Rice Attenuates UVB-ROS-Induced Skin Aging via Downregulation of Inflammatory Cascades

PubMed Central

Lee, Taek Hwan; Wahedi, Hussain Mustatab; Baek, So-Hyeon

2017-01-01

The skin is the outermost protective barrier between the internal and external environments in humans. Chronic exposure to ultraviolet (UV) radiation is a major cause of skin aging. UVB radiation penetrates the skin and induces ROS production that activates three major skin aging cascades: matrix metalloproteinase- (MMP-) 1-mediated aging; MAPK-AP-1/NF-κB-TNF-α/IL-6, iNOS, and COX-2-mediated inflammation-induced aging; and p53-Bax-cleaved caspase-3-cytochrome C-mediated apoptosis-induced aging. These mechanisms are collectively responsible for the wrinkling and photoaging characteristic of UVB-induced skin aging. There is an urgent requirement for a treatment that not only controls these pathways to prevent skin aging but also avoids the adverse effects often encountered when applying bioactive compounds in concentrated doses. In this study, we investigated the efficacy of genetically modified normal edible rice (NR) that produces the antiaging compound resveratrol (R) as a treatment for skin aging. This resveratrol-enriched rice (RR) overcomes the drawbacks of R and enhances its antiaging potential by controlling the abovementioned three major pathways of skin aging. RR does not exhibit the toxicity of R alone and promisingly downregulates the pathways underlying UVB-ROS-induced skin aging. These findings advocate the use of RR as a nutraceutical for antiaging purposes. PMID:28900534

Resveratrol-Enriched Rice Attenuates UVB-ROS-Induced Skin Aging via Downregulation of Inflammatory Cascades.

PubMed

Subedi, Lalita; Lee, Taek Hwan; Wahedi, Hussain Mustatab; Baek, So-Hyeon; Kim, Sun Yeou

2017-01-01

The skin is the outermost protective barrier between the internal and external environments in humans. Chronic exposure to ultraviolet (UV) radiation is a major cause of skin aging. UVB radiation penetrates the skin and induces ROS production that activates three major skin aging cascades: matrix metalloproteinase- (MMP-) 1-mediated aging; MAPK-AP-1/NF- κ B-TNF- α /IL-6, iNOS, and COX-2-mediated inflammation-induced aging; and p53-Bax-cleaved caspase-3-cytochrome C-mediated apoptosis-induced aging. These mechanisms are collectively responsible for the wrinkling and photoaging characteristic of UVB-induced skin aging. There is an urgent requirement for a treatment that not only controls these pathways to prevent skin aging but also avoids the adverse effects often encountered when applying bioactive compounds in concentrated doses. In this study, we investigated the efficacy of genetically modified normal edible rice (NR) that produces the antiaging compound resveratrol (R) as a treatment for skin aging. This resveratrol-enriched rice (RR) overcomes the drawbacks of R and enhances its antiaging potential by controlling the abovementioned three major pathways of skin aging. RR does not exhibit the toxicity of R alone and promisingly downregulates the pathways underlying UVB-ROS-induced skin aging. These findings advocate the use of RR as a nutraceutical for antiaging purposes.

Controlling reactive oxygen species in skin at their source to reduce skin aging.

PubMed

Kern, Dale G; Draelos, Zoe D; Meadows, Christiaan; James Morré, D; Morré, Dorothy M

2010-01-01

Activity of an age-related, superoxide-forming, cell-surface oxidase (arNOX) comparing dermis, epidermis, serum, and saliva from female and male subjects ages 28-72 years measured spectrophotometrically using reduction of ferricytochrome c correlated with oxidative skin damage as estimated from autofluoresence of skin using an Advanced Glycation End products Reader (AGE-Reader; DiagnOptics B.V., Netherlands). By reducing arNOX activity in skin with arNOX-inhibitory ingredients (NuSkin's ageLOC technology), skin appearance was improved through decreased protein cross-linking and an accelerated increase in collagen.

Analyses of volatile organic compounds from human skin

PubMed Central

Gallagher, M.; Wysocki, C.J.; Leyden, J.J.; Spielman, A.I.; Sun, X.; Preti, G.

2008-01-01

Summary Background Human skin emits a variety of volatile metabolites, many of them odorous. Much previous work has focused upon chemical structure and biogenesis of metabolites produced in the axillae (underarms), which are a primary source of human body odour. Nonaxillary skin also harbours volatile metabolites, possibly with different biological origins than axillary odorants. Objectives To take inventory of the volatile organic compounds (VOCs) from the upper back and forearm skin, and assess their relative quantitative variation across 25 healthy subjects. Methods Two complementary sampling techniques were used to obtain comprehensive VOC profiles, viz., solid-phase micro extraction and solvent extraction. Analyses were performed using both gas chromatography/mass spectrometry and gas chromatography with flame photometric detection. Results Nearly 100 compounds were identified, some of which varied with age. The VOC profiles of the upper back and forearm within a subject were, for the most part, similar, although there were notable differences. Conclusions The natural variation in nonaxillary skin odorants described in this study provides a baseline of compounds we have identified from both endogenous and exogenous sources. Although complex, the profiles of volatile constituents suggest that the two body locations share a considerable number of compounds, but both quantitative and qualitative differences are present. In addition, quantitative changes due to ageing are also present. These data may provide future investigators of skin VOCs with a baseline against which any abnormalities can be viewed in searching for biomarkers of skin diseases. PMID:18637798

Elastin hydrolysate derived from fish enhances proliferation of human skin fibroblasts and elastin synthesis in human skin fibroblasts and improves the skin conditions.

PubMed

Shiratsuchi, Eri; Nakaba, Misako; Yamada, Michio

2016-03-30

Recent studies have shown that certain peptides significantly improve skin conditions, such as skin elasticity and the moisture content of the skin of healthy woman. This study aimed to investigate the effects of elastin hydrolysate on human skin. Proliferation and elastin synthesis were evaluated in human skin fibroblasts exposed to elastin hydrolysate and proryl-glycine (Pro-Gly), which is present in human blood after elastin hydrolysate ingestion. We also performed an ingestion test with elastin hydrolysate in humans and evaluated skin condition. Elastin hydrolysate and Pro-Gly enhanced the proliferation of fibroblasts and elastin synthesis. Maximal proliferation response was observed at 25 ng mL(-1) Pro-Gly. Ingestion of elastin hydrolysate improved skin condition, such as elasticity, number of wrinkles, and blood flow. Elasticity improved by 4% in the elastin hydrolysate group compared with 2% in the placebo group. Therefore, elastin hydrolysate activates human skin fibroblasts and has beneficial effects on skin conditions. © 2015 Society of Chemical Industry.

Relationship between Aging-Related Skin Dryness and Aquaporins

PubMed Central

Ikarashi, Nobutomo; Kon, Risako; Kaneko, Miho; Mizukami, Nanaho; Kusunoki, Yoshiki; Sugiyama, Kiyoshi

2017-01-01

Skin function deteriorates with aging, and the dermal water content decreases. In this study, we have analyzed the mechanism of aging-related skin dryness focusing on aquaporins (AQPs), which are the water channels. Mice aged 3 and 20 months were designated as young and aged mice, respectively, to be used in the experiments. No differences were observed in transepidermal water loss between the young mice and aged mice. However, the dermal water content in aged mice was significantly lower than that in young mice, thus showing skin dryness. The expression of AQP1, AQP3, AQP4, AQP7, and AQP9 was observed in the skin. All the mRNA expression levels of these AQPs were significantly lower in aged mice. For AQP3, which was expressed dominantly in the skin, the protein level was lower in aged mice than in young mice. The results of the study showed that the expression level of AQPs in the skin decreased with aging, suggesting the possibility that this was one of the causes of skin dryness. New targets for the prevention and treatment of aging-related skin dryness are expected to be proposed when the substance that increases the expression of AQP3 is found. PMID:28718791

Activation of Peroxisome Proliferator-Activated Receptor Alpha Improves Aged and UV-Irradiated Skin by Catalase Induction.

PubMed

Shin, Mi Hee; Lee, Se-Rah; Kim, Min-Kyoung; Shin, Chang-Yup; Lee, Dong Hun; Chung, Jin Ho

2016-01-01

Peroxisome proliferator-activated receptor alpha (PPARα) is a nuclear hormone receptor involved in the transcriptional regulation of lipid metabolism, fatty acid oxidation, and glucose homeostasis. Its activation stimulates antioxidant enzymes such as catalase, whose expression is decreased in aged human skin. Here we investigated the expression of PPARα in aged and ultraviolet (UV)-irradiated skin, and whether PPARα activation can modulate expressions of matrix metalloproteinase (MMP)-1 and procollagen through catalase regulation. We found that PPARα mRNA level was significantly decreased in intrinsically aged and photoaged human skin as well as in UV-irradiated skin. A PPARα activator, Wy14643, inhibited UV-induced increase of MMP-1 and decrease of procollagen expression and caused marked increase in catalase expression. Furthermore, production of reactive oxygen species (ROS) was suppressed by Wy14643 in UV-irradiated and aged dermal fibroblasts, suggesting that the PPARα activation-induced upregulation of catalase leads to scavenging of ROS produced due to UV irradiation or aging. PPARα knockdown decreased catalase expression and abolished the beneficial effects of Wy14643. Topical application of Wy14643 on hairless mice restored catalase activity and prevented MMP-13 and inflammatory responses in skin. Our findings indicate that PPARα activation triggers catalase expression and ROS scavenging, thereby protecting skin from UV-induced damage and intrinsic aging.

Cytokine mRNA expression in normal skin of various age populations before and after engraftment onto nude mice.

PubMed

Gilhar, A; Ullmann, Y; Shalagino, R; Weisinger, G

1998-01-01

Whether the impact of skin biological age on cytokine expression is a result of this tissue's proliferation potential or not is an important issue in dermatology. We investigated these questions by monitoring cytokine marker mRNA expression from human skin samples from healthy groups of individuals. The skin samples studied represented three age groups: fetal (17-21 weeks), young (18-35 years) and aged (76-88 years). Furthermore, upon skin transplantation of tissue from different age groups onto nude mice, we investigated whether cytokine marker RNA levels would change or normalize. Interestingly, both TNF-alpha and P53 mRNA showed a similar pattern of expression. Both were significantly higher in fetal skin (p < 0.0001 and p < 0.05, respectively), and no difference was noted between aged versus young skin. In contrast to this, IL1-alpha mRNA was expressed at its lowest and highest levels in fetal and young skin, respectively. Following skin transplantation, cytokines and P53 mRNA expression were normalized to similar levels in all age groups. This study implies that when cytokine expression was determined directly at the mRNA level, post-natal expression was not significantly different at either age group. Furthermore, it seems that the environmental conditions surrounding the grafted human skin found on nude mice encouraged normalization of donor cytokine expression.

Skin aging and menopause : implications for treatment.

PubMed

Raine-Fenning, Nicholas J; Brincat, Mark P; Muscat-Baron, Yves

2003-01-01

The skin is one of the largest organs of the body, which is significantly affected by the aging process and menopause. The significant changes sustained by the skin during the menopause are due to the effect sustained on the skin's individual components. The estrogen receptor has been detected on the cellular components of the skin. Accordingly, dermal cellular metabolism is influenced by the hypoestrogenoemic state of menopause leading to changes in the collagen content, alterations in the concentration of glycoaminoglycans and most importantly the water content. Consequently changes in these basic components leads to an alteration in function compatible with skin aging. Changes in the skin collagen leads to diminished elasticity and skin strength. Collagen content may be measured by various methods such as direct skin biopsy, skin blister assessment for collagen markers and skin thickness measurement. All these variables indicate a reduction in collagen content following menopause. This may be reversed with the administration of estrogen given both topically and systemically.A reduction in hydrophilic glycoaminglycans leads to a direct reduction in water content, which influences the skin turgor. These effects on glycoaminoglycans, due to the hypoestrogenia, have been clearly shown in animal studies and appeared to be rapidly reversed with the application of estrogens. The sum total of these basic effects on the skin leads to wrinkles, the skin condition typifying skin aging.Structures resident in the skin are likewise influenced by menopause. Changes to the cutaneous vascular reactivity are noted following menopause. Capillary blood flow velocity decreases significantly in postmenopausal women. Postmenopausal flushing is due to profound vasodilatation in the dermal papillae. Hair growth is also influenced by the hormonal milieu and consequently hair loss has been associated with the beginning of menopause. Treatments administered for menopause, in particular

[Skin aging and evidence-based topical strategies].

PubMed

Bayerl, C

2016-02-01

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.

Preparation of Artificial Skin that Mimics Human Skin Surface and Mechanical Properties.

PubMed

Shimizu, Rana; Nonomura, Yoshimune

2018-01-01

We have developed an artificial skin that mimics the morphological and mechanical properties of human skin. The artificial skin comprises a polyurethane block possessing a microscopically rough surface. We evaluated the tactile sensations when skin-care cream was applied to the artificial skin. Many subjects perceived smooth, moist, and soft feels during the application process. Cluster analysis showed that these characteristic tactile feels are similar to those when skin-care cream is applied to real human skin. Contact angle analysis showed that an oil droplet spread smoothly on the artificial skin surface, which occurred because there were many grooves several hundred micrometers in width on the skin surface. In addition, when the skin-care cream was applied, the change in frictional force during the dynamic friction process increased. These wetting and frictional properties are important factors controlling the similarity of artificial skin to real human skin.

The matricellular protein periostin contributes to proper collagen function and is downregulated during skin aging.

PubMed

Egbert, M; Ruetze, M; Sattler, M; Wenck, H; Gallinat, S; Lucius, R; Weise, J M

2014-01-01

Periostin is a secreted 90kDa matricellular protein, which is predominantly expressed in collagen-rich tissues. Collagen is the most abundant protein in mammals and has great tensile strength. Recent investigations have shown that periostin influences collagen fibrillogenesis and biomechanical properties of murine connective tissues. We investigated the function of periostin concerning collagen homeostasis during intrinsic and extrinsic skin aging. For this purpose, human skin samples of young and old donors as well as samples of photoaged and sun-protected skin areas were analyzed for periostin expression. Using in vitro models, we determined the cell types responsible for periostin expression and performed functional analyses with periostin knockdown cells. TaqMan Real-Time PCR, UV irradiation, knockdown experiments, immunostaining, electron microscopy, collagen degradation assay, collagen crosslink analysis. Periostin expression is highest in the papillary dermis and downregulated during skin aging. Fibroblasts and non-follicular skin derived precursors were identified as main source for periostin expression in human skin. Periostin knockdown in fibroblasts has no effect on collagen expression, but results in an increased fibril diameter and aberrant collagen structure. This leads to an increased susceptibility of collagen toward proteases, whereas recombinant periostin protects collagen fibrils from degradation. Our data show that periostin plays an important role for proper collagen assembly and homeostasis. During skin aging periostin expression decreases and contributes to the phenotype of aged skin. Copyright © 2013 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

Poly herbal formulation with anti-elastase and anti-oxidant properties for skin anti-aging.

PubMed

Kalyana Sundaram, Induja; Sarangi, Deepika Deeptirekha; Sundararajan, Vignesh; George, Shinomol; Sheik Mohideen, Sahabudeen

2018-01-29

Skin forms an important part of human innate immune system. Wrinkles, thinning and roughening of skin are some of the symptoms that affect the skin as it ages. Reactive oxygen species induced oxidative stress plays a major role in skin aging by modulating the elastase enzyme level in the skin. Extrinsic factors that affect skin aging such as UV radiation can also cause malignant melanoma. Here we selected four medicinal plant materials, namely, leaves of Nyctanthes arbor-tristis, unripe and ripe Aegle marmelos fruit pulp and the terminal meristem of Musa paradisiaca flower and investigated their anti-aging properties and cytotoxicity in vitro individually as well as in a poly herbal formulation containing the four plant extracts in different ratios. The phytochemical contents of the plant extracts were investigated for radical scavenging activity and total reducing power. Based upon its anti-oxidant properties, a poly herbal formulation containing leaves of Nyctanthes arbor-tristis, unripe and ripe fruit pulp of Aegle marmelos, and the terminal meristem of Musa paradisiaca flower in the ratio 6:2:1:1 (Poly Herbal Formulation 1) and 1:1:1:1 (Poly Herbal Formulation 2), respectively were formulated. It has been observed that the Poly Herbal Formulation 1 was more potent than Poly Herbal Formulation 2 due to better anti-oxidant and anti-elastase activities in NIH3T3 fibroblast cells. In addition Poly Herbal formulation 1 also had better anti-cancer activity in human malignant melanoma cells. Based on these results these beneficial plant extracts were identified for its potential application as an anti-aging agent in skin creams as well as an anti-proliferation compound against cancer cells.

Protective effects of skin permeable epidermal and fibroblast growth factor against ultraviolet-induced skin damage and human skin wrinkles.

PubMed

An, Jae Jin; Eum, Won Sik; Kwon, Hyuck Se; Koh, Jae Sook; Lee, Soo Yun; Baek, Ji Hwoon; Cho, Yong-Jun; Kim, Dae Won; Han, Kyu Huyng; Park, Jinseu; Jang, Sang Ho; Choi, Soo Young

2013-12-01

Epidermal and fibroblast growth factor (EGF and FGF1) proteins play an important role in the regeneration and proliferation of skin cells. EGF and FGF1 have considerable potential as possible therapeutic or cosmetic agents for the treatment of skin damage including wrinkles. Using protein transduction domains (PTD), we investigated whether PTD-EGF and FGF1 transduced into skin cells and tissue. Transduced proteins showed protective effects in a UV-induced skin damage model as well as against skin wrinkles. Transduced PTD-EGF and FGF1 proteins were detected by immunofluorescence and immunohistochemistry. The effects of PTD-EGF and FGF1 were examined by WST assay, Western blotting, immunohistochemistry, and skin wrinkle parameters. The PTD-EGF and FGF1 increased cell proliferation and collagen type 1 alpha 1 protein accumulation in skin tissue. Also, PTD-EGF and FGF1 inhibited UV-induced skin damage. Furthermore, topical application of PTD-EGF and FGF1 contained ampoules which were considered to improve the wrinkle parameters of human skin. These results show that PTD-EGF and FGF1 can be a potential therapeutic or cosmetic agent for skin damaged and injury including wrinkles and aging. © 2013 Wiley Periodicals, Inc.

Skin aging: are adipocytes the next target?

PubMed

Kruglikov, Ilja L; Scherer, Philipp E

2016-07-01

Dermal white adipose tissue (dWAT) is increasingly appreciated as a special fat depot. The adipocytes in this depot exert a variety of unique effects on their surrounding cells and can undergo massive phenotypic changes. Significant modulation of dWAT content can be observed both in intrinsically and extrinsically aged skin. Specifically, skin that has been chronically photo-damaged displays a reduction of the dWAT volume, caused by the replacement of adipocytes by fibrotic structures. This is likely to be caused by the recently uncovered process described as "adipocyte-myofibroblast transition" (AMT). In addition, contributions of dermal adipocytes to the skin aging processes are also indirectly supported by spatial correlations between the prevalence of hypertrophic scarring and the appearance of signs of skin aging in different ethnic groups. These observations could elevate dermal adipocytes to prime targets in strategies aimed at counteracting skin aging.

Skin aging: are adipocytes the next target?

PubMed Central

Kruglikov, Ilja L.; Scherer, Philipp E.

2016-01-01

Dermal white adipose tissue (dWAT) is increasingly appreciated as a special fat depot. The adipocytes in this depot exert a variety of unique effects on their surrounding cells and can undergo massive phenotypic changes. Significant modulation of dWAT content can be observed both in intrinsically and extrinsically aged skin. Specifically, skin that has been chronically photo-damaged displays a reduction of the dWAT volume, caused by the replacement of adipocytes by fibrotic structures. This is likely to be caused by the recently uncovered process described as “adipocyte-myofibroblast transition” (AMT). In addition, contributions of dermal adipocytes to the skin aging processes are also indirectly supported by spatial correlations between the prevalence of hypertrophic scarring and the appearance of signs of skin aging in different ethnic groups. These observations could elevate dermal adipocytes to prime targets in strategies aimed at counteracting skin aging. PMID:27434510

Activation of Peroxisome Proliferator-Activated Receptor Alpha Improves Aged and UV-Irradiated Skin by Catalase Induction

PubMed Central

Shin, Mi Hee; Lee, Se-Rah; Kim, Min-Kyoung; Shin, Chang-Yup

2016-01-01

Peroxisome proliferator-activated receptor alpha (PPARα) is a nuclear hormone receptor involved in the transcriptional regulation of lipid metabolism, fatty acid oxidation, and glucose homeostasis. Its activation stimulates antioxidant enzymes such as catalase, whose expression is decreased in aged human skin. Here we investigated the expression of PPARα in aged and ultraviolet (UV)-irradiated skin, and whether PPARα activation can modulate expressions of matrix metalloproteinase (MMP)-1 and procollagen through catalase regulation. We found that PPARα mRNA level was significantly decreased in intrinsically aged and photoaged human skin as well as in UV-irradiated skin. A PPARα activator, Wy14643, inhibited UV-induced increase of MMP-1 and decrease of procollagen expression and caused marked increase in catalase expression. Furthermore, production of reactive oxygen species (ROS) was suppressed by Wy14643 in UV-irradiated and aged dermal fibroblasts, suggesting that the PPARα activation-induced upregulation of catalase leads to scavenging of ROS produced due to UV irradiation or aging. PPARα knockdown decreased catalase expression and abolished the beneficial effects of Wy14643. Topical application of Wy14643 on hairless mice restored catalase activity and prevented MMP-13 and inflammatory responses in skin. Our findings indicate that PPARα activation triggers catalase expression and ROS scavenging, thereby protecting skin from UV-induced damage and intrinsic aging. PMID:27611371

Assessing the impacts of lifetime sun exposure on skin damage and skin aging using a non-invasive method.

PubMed

Kimlin, Michael G; Guo, Yuming

2012-05-15

Ultraviolet radiation exposure during an individuals' lifetime is a known risk factor for the development of skin cancer. However, less evidence is available on assessing the relationship between lifetime sun exposure and skin damage and skin aging. This study aims to assess the relationship between lifetime sun exposure and skin damage and skin aging using a non-invasive measure of exposure. We recruited 180 participants (73 males, 107 females) aged 18-83 years. Digital imaging of skin hyperpigmentation (skin damage) and skin wrinkling (skin aging) on the facial region was measured. Lifetime sun exposure (presented as hours) was calculated from the participants' age multiplied by the estimated annual time outdoors for each year of life. We analyzed the effects of lifetime sun exposure on skin damage and skin aging. We adjust for the influence of age, sex, occupation, history of skin cancer, eye color, hair color, and skin color. There were non-linear relationships between lifetime sun exposure and skin damage and skin aging. Younger participant's skin is much more sensitive to sun exposure than those who were over 50 years of age. As such, there were negative interactions between lifetime sun exposure and age. Age had linear effects on skin damage and skin aging. The data presented showed that self reported lifetime sun exposure was positively associated with skin damage and skin aging, in particular, the younger people. Future health promotion for sun exposure needs to pay attention to this group for skin cancer prevention messaging. Copyright © 2012 Elsevier B.V. All rights reserved.

Skin Ageing: Natural Weapons and Strategies

PubMed Central

Binic, Ivana; Lazarevic, Viktor; Ljubenovic, Milanka; Mojsa, Jelena; Sokolovic, Dusan

2013-01-01

The fact that the skin is the most visible organ makes us aware of the ageing process every minute. The use of plant extracts and herbs has its origins in ancient times. Chronological and photo-ageing can be easily distinguished clinically, but they share important molecular features. We tried to gather the most interesting evidence based on facts about plants and plant extracts used in antiaging products. Our main idea was to emphasize action mechanisms of these plant/herbal products, that is, their “strategies” in fighting skin ageing. Some of the plant extracts have the ability to scavenge free radicals, to protect the skin matrix through the inhibition of enzymatic degradation, or to promote collagen synthesis in the skin. There are some plants that can affect skin elasticity and tightness. Certainly, there is a place for herbal principles in antiaging cosmetics. On the other hand, there is a constant need for more evaluation and more clinical studies in vivo with emphasis on the ingredient concentration of the plant/herbal products, its formulation, safety, and duration of the antiaging effect. PMID:23431351

Assessing human skin with diffuse reflectance spectroscopy and colorimetry

NASA Astrophysics Data System (ADS)

Seo, InSeok; Liu, Yang; Bargo, Paulo R.; Kollias, Nikiforos

2012-02-01

Colorimetry has been used as an objective measure of perceived skin color by human eye to document and score physiological responses of the skin from external insults. CIE color space values (L*, a* and b*) are the most commonly used parameters to correlate visually perceived color attributes such as L* for pigment, a* for erythema, and b* for sallowness of the skin. In this study, we investigated the relation of Lab color scale to the amount of major skin chromophores (oxy-, deoxyhemoglobin and melanin) calculated from diffuse reflectance spectroscopy. Thirty two healthy human subjects with ages from 20 to 70 years old, skin types I-VI, were recruited for the study. DRS and colorimetry measurements were taken from the left and right cheeks, and on the right upper inner arm. The melanin content calculated from 630-700 nm range of DRS measurements was shown to correlate with the lightness of skin (L*) for most skin types. For subjects with medium-to-light complexion, melanin measured at the blue part spectrum and hemoglobin interfered on the relation of lightness of the skin color to the melanin content. The sallowness of the skin that is quantified by the melanin contribution at the blue part spectrum of DRS was found to be related to b* scale. This study demonstrates the importance of documenting skin color by assessing individual skin chromophores with diffuse reflectance spectroscopy, in comparison to colorimetry assessment.

Wound healing delays in α-Klotho-deficient mice that have skin appearance similar to that in aged humans - Study of delayed wound healing mechanism.

PubMed

Yamauchi, Makoto; Hirohashi, Yoshihiko; Torigoe, Toshihiko; Matsumoto, Yoshitaka; Yamashita, Ken; Kayama, Musashi; Sato, Noriyuki; Yotsuyanagi, Takatoshi

2016-05-13

Skin atrophy and delayed wound healing are observed in aged humans; however, the molecular mechanism are still elusive. The aim of this study was to analyze the molecular mechanisms of delayed wound healing by aging using α-Klotho-deficient (kl/kl) mice, which have phenotypes similar to those of aged humans. The kl/kl mice showed delayed wound healing and impaired granulation formation compared with those in wild-type (WT) mice. The skin graft experiments revealed that delayed wound healing depends on humoral factors, but not on kl/kl skin tissue. The mRNA expression levels of cytokines related to acute inflammation including IL-1β, IL-6 and TNF-α were higher in wound lesions of kl/kl mice compared with the levels in WT mice by RT-PCR analysis. LPS-induced TNF-α production model using spleen cells revealed that TNF-α production was significantly increased in the presence of FGF23. Thus, higher levels of FGF23 in kl/kl mouse may have a role to increase TNF-α production in would lesion independently of α-Klotho protein, and impair granulation formation and delay wound healing. Copyright © 2016 Elsevier Inc. All rights reserved.

Genetic polymorphisms and skin aging: the identification of population genotypic groups holds potential for personalized treatments.

PubMed

Naval, Jordi; Alonso, Vicente; Herranz, Miquel Angel

2014-01-01

Skin changes are among the most visible signs of aging. Skin properties such as hydration, elasticity, and antioxidant capacity play a key role in the skin aging process. Skin aging is a complex process influenced by heritable and environmental factors. Recent studies on twins have revealed that up to 60% of the skin aging variation between individuals can be attributed to genetic factors, while the remaining 40% is due to non-genetic factors. Recent advances in genomics and bioinformatics approaches have led to the association of certain single nucleotide polymorphisms (SNPs) to skin properties. Our aim was to classify individuals based on an ensemble of multiple polymorphisms associated with certain properties of the skin for providing personalized skin care and anti-aging therapies. We identified the key proteins and SNPs associated with certain properties of the skin that contribute to skin aging. We selected a set of 13 SNPs in gene coding for these proteins which are potentially associated with skin aging. Finally, we classified a sample of 120 female volunteers into ten clusters exhibiting different skin properties according to their genotypic signature. This is the first study that describes the actual frequency of genetic polymorphisms and their distribution in clusters involved in skin aging in a Caucasian population. Individuals can be divided into genetic clusters defined by genotypic variables. These genotypic variables are linked with polymorphisms in one or more genes associated with certain properties of the skin that contribute to a person's perceived age. Therefore, by using this classification, it is possible to characterize human skin care and anti-aging needs on the basis of an individual's genetic signature, thus opening the door to personalized treatments addressed at specific populations. This is part of an ongoing effort towards personalized anti-aging therapies combining genetic signatures with environmental and life style evaluations.

The cutaneous ecosystem: the roles of the skin microbiome in health and its association with inflammatory skin conditions in humans and animals.

PubMed

Rodrigues Hoffmann, Aline

2017-02-01

Inhabiting a sterile world is no longer an acceptable or desirable concept. Recent studies developed in the microbiome field have unveiled complex microbial populations inhabiting the skin, digestive, respiratory and reproductive tracts. Microbiome studies have opened new venues to explore the human and animal second genome, its functions and its importance in maintaining health. The composition of the skin microbiome varies across different body sites and across individuals, being influenced by different host habits, including for instance age, sex, diet, hygiene and lifestyle. Exposure to a diverse skin microbiome is now considered to be a key component in immune regulation, and imbalances in these microbial populations are being associated with human and animal skin inflammatory disorders. We have learned that in several skin conditions, there is a significant alteration in the diversity and composition of the microbiota colonizing the skin. For instance, in human and animal patients with atopic dermatitis, dysbiosis of the skin microbiota results in lower diversity of microbial populations. Whether these altered microbial populations are the cause or the effect of inflammatory skin conditions seen in humans and animals are still under investigation, but there is no doubt that the microbiome has an important role in maintaining skin health. This review focuses on the most current studies describing the skin microbiome in humans and animals, its role in modulating the immune system, and its association with human and animal skin diseases. © 2017 ESVD and ACVD.

Human Skin Fungal Diversity

PubMed Central

Findley, Keisha; Oh, Julia; Yang, Joy; Conlan, Sean; Deming, Clayton; Meyer, Jennifer A.; Schoenfeld, Deborah; Nomicos, Effie; Park, Morgan; Kong, Heidi H.; Segre, Julia A.

2013-01-01

Traditional culture-based methods have incompletely defined the etiology of common recalcitrant human fungal skin diseases including athlete’s foot and toenail infections. Skin protects humans from invasion by pathogenic microorganisms, while providing a home for diverse commensal microbiota1. Bacterial genomic sequence data have generated novel hypotheses about species and community structures underlying human disorders2,3,4. However, microbial diversity is not limited to bacteria; microorganisms such as fungi also play major roles in microbial community stability, human health and disease5. Genomic methodologies to identify fungal species and communities have been limited compared with tools available for bacteria6. Fungal evolution can be reconstructed with phylogenetic markers, including ribosomal RNA gene regions and other highly conserved genes7. Here, we sequenced and analyzed fungal communities of 14 skin sites in 10 healthy adults. Eleven core body and arm sites were dominated by Malassezia fungi, with species-level classifications revealing greater topographical resolution between sites. By contrast, three foot sites, plantar heel, toenail, and toeweb, exhibited tremendous fungal diversity. Concurrent analysis of bacterial and fungal communities demonstrated that skin physiologic attributes and topography differentially shape these two microbial communities. These results provide a framework for future investigation of interactions between pathogenic and commensal fungal and bacterial communities in maintaining human health and contributing to disease pathogenesis. PMID:23698366

Enhancement of human skin facial revitalization by moringa leaf extract cream.

PubMed

Ali, Atif; Akhtar, Naveed; Chowdhary, Farzana

2014-05-01

Solar ultraviolet exposure is the main cause of skin damage by initiation of reactive oxygen species (ROS) leading to skin collagen imperfection and eventually skin roughness. This can be reduced by proper revitalization of skin enhancing younger and healthier appearance. To evaluate the skin facial revitalization effect of a cream formulation containing the Moringa oleifera leaf extract on humans. Active cream containing 3% of the concentrated extract of moringa leaves was developed by entrapping in the inner aqueous phase of cream. Base contained no extract. Skin revitalizing parameters, i.e. surface, volume, texture parameters and surface evaluation of the living skin (SELS) were assessed comparatively after application of the base and active cream on human face using Visioscan(®) VC 98 for a period of 3 months. Surface values were increased by the base and decreased by the active cream. Effects produced for the base and active cream were significant and insignificant, respectively, as observed in the case of surface. Unlike the base, the active cream showed significant effects on skin volume, texture parameters (energy, variance and contrast) and SELS, SEr (skin roughness), SEsc (skin scaliness), SEsm (skin smoothness), and SEw (skin wrinkles) parameters. The results suggested that moringa cream enhances skin revitalization effect and supports anti-aging skin effects.

Image analysis of skin color heterogeneity focusing on skin chromophores and the age-related changes in facial skin.

PubMed

Kikuchi, Kumiko; Masuda, Yuji; Yamashita, Toyonobu; Kawai, Eriko; Hirao, Tetsuji

2015-05-01

Heterogeneity with respect to skin color tone is one of the key factors in visual perception of facial attractiveness and age. However, there have been few studies on quantitative analyses of the color heterogeneity of facial skin. The purpose of this study was to develop image evaluation methods for skin color heterogeneity focusing on skin chromophores and then characterize ethnic differences and age-related changes. A facial imaging system equipped with an illumination unit and a high-resolution digital camera was used to develop image evaluation methods for skin color heterogeneity. First, melanin and/or hemoglobin images were obtained using pigment-specific image-processing techniques, which involved conversion from Commission Internationale de l'Eclairage XYZ color values to melanin and/or hemoglobin indexes as measures of their contents. Second, a spatial frequency analysis with threshold settings was applied to the individual images. Cheek skin images of 194 healthy Asian and Caucasian female subjects were acquired using the imaging system. Applying this methodology, the skin color heterogeneity of Asian and Caucasian faces was characterized. The proposed pigment-specific image-processing techniques allowed visual discrimination of skin redness from skin pigmentation. In the heterogeneity analyses of cheek skin color, age-related changes in melanin were clearly detected in Asian and Caucasian skin. Furthermore, it was found that the heterogeneity indexes of hemoglobin were significantly higher in Caucasian skin than in Asian skin. We have developed evaluation methods for skin color heterogeneity by image analyses based on the major chromophores, melanin and hemoglobin, with special reference to their size. This methodology focusing on skin color heterogeneity should be useful for better understanding of aging and ethnic differences. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Impact of Age and Insulin-Like Growth Factor-1 on DNA Damage Responses in UV-Irradiated Human Skin.

PubMed

Kemp, Michael G; Spandau, Dan F; Travers, Jeffrey B

2017-02-26

The growing incidence of non-melanoma skin cancer (NMSC) necessitates a thorough understanding of its primary risk factors, which include exposure to ultraviolet (UV) wavelengths of sunlight and age. Whereas UV radiation (UVR) has long been known to generate photoproducts in genomic DNA that promote genetic mutations that drive skin carcinogenesis, the mechanism by which age contributes to disease pathogenesis is less understood and has not been sufficiently studied. In this review, we highlight studies that have considered age as a variable in examining DNA damage responses in UV-irradiated skin and then discuss emerging evidence that the reduced production of insulin-like growth factor-1 (IGF-1) by senescent fibroblasts in the dermis of geriatric skin creates an environment that negatively impacts how epidermal keratinocytes respond to UVR-induced DNA damage. In particular, recent data suggest that two principle components of the cellular response to DNA damage, including nucleotide excision repair and DNA damage checkpoint signaling, are both partially defective in keratinocytes with inactive IGF-1 receptors. Overcoming these tumor-promoting conditions in aged skin may therefore provide a way to lower aging-associated skin cancer risk, and thus we will consider how dermal wounding and related clinical interventions may work to rejuvenate the skin, re-activate IGF-1 signaling, and prevent the initiation of NMSC.

Impact of Age and Insulin-Like Growth Factor-1 on DNA Damage Responses in UV-Irradiated Human Skin

PubMed Central

Kemp, Michael G.; Spandau, Dan F; Travers, Jeffrey B.

2017-01-01

The growing incidence of non-melanoma skin cancer (NMSC) necessitates a thorough understanding of its primary risk factors, which include exposure to ultraviolet (UV) wavelengths of sunlight and age. Whereas UV radiation (UVR) has long been known to generate photoproducts in genomic DNA that promote genetic mutations that drive skin carcinogenesis, the mechanism by which age contributes to disease pathogenesis is less understood and has not been sufficiently studied. In this review, we highlight studies that have considered age as a variable in examining DNA damage responses in UV-irradiated skin and then discuss emerging evidence that the reduced production of insulin-like growth factor-1 (IGF-1) by senescent fibroblasts in the dermis of geriatric skin creates an environment that negatively impacts how epidermal keratinocytes respond to UVR-induced DNA damage. In particular, recent data suggest that two principle components of the cellular response to DNA damage, including nucleotide excision repair and DNA damage checkpoint signaling, are both partially defective in keratinocytes with inactive IGF-1 receptors. Overcoming these tumor-promoting conditions in aged skin may therefore provide a way to lower aging-associated skin cancer risk, and thus we will consider how dermal wounding and related clinical interventions may work to rejuvenate the skin, re-activate IGF-1 signaling, and prevent the initiation of NMSC. PMID:28245638

Modulation of telomere binding proteins: a future area of research for skin protection and anti-aging target.

PubMed

Imbert, Isabelle; Botto, Jean-Marie; Farra, Claude D; Domloge, Nouha

2012-06-01

Telomere shortening is considered as one of the main characteristics of cellular aging by limiting cellular division. Besides the fundamental advances through the discoveries of telomere and telomerase, which were recognized by a Nobel Prize, telomere protection remains an essential area of research. Recently, it was evidenced that studying the cross-talks between the proteins associated with telomere should provide a better understanding of the mechanistic basis for telomere-associated aging phenotypes. In this review, we discuss the current knowledge on telomere shortening, telomerase activity, and the essential role of telomere binding proteins in telomere stabilization and telomere-end protection. This review highlights the capacity of telomere binding proteins to limit cellular senescence and to maintain skin tissue homeostasis, which is of key importance to reduce accelerated tissue aging. Future studies addressing telomere protection and limitation of DNA damage response in human skin should include investigations on telomere binding proteins. As little is known about the expression of telomere binding proteins in human skin and modulation of their expression with aging, it remains an interesting field of skin research and a key area for future skin protection and anti-aging developments. © 2012 Wiley Periodicals, Inc.

An ex vivo human skin model for studying skin barrier repair.

PubMed

Danso, Mogbekeloluwa O; Berkers, Tineke; Mieremet, Arnout; Hausil, Farzia; Bouwstra, Joke A

2015-01-01

In the studies described in this study, we introduce a novel ex vivo human skin barrier repair model. To develop this, we removed the upper layer of the skin, the stratum corneum (SC) by a reproducible cyanoacrylate stripping technique. After stripping the explants, they were cultured in vitro to allow the regeneration of the SC. We selected two culture temperatures 32 °C and 37 °C and a period of either 4 or 8 days. After 8 days of culture, the explant generated SC at a similar thickness compared to native human SC. At 37 °C, the early and late epidermal differentiation programmes were executed comparably to native human skin with the exception of the barrier protein involucrin. At 32 °C, early differentiation was delayed, but the terminal differentiation proteins were expressed as in stripped explants cultured at 37 °C. Regarding the barrier properties, the SC lateral lipid organization was mainly hexagonal in the regenerated SC, whereas the lipids in native human SC adopt a more dense orthorhombic organization. In addition, the ceramide levels were higher in the cultured explants at 32 °C and 37 °C than in native human SC. In conclusion, we selected the stripped ex vivo skin model cultured at 37 °C as a candidate model to study skin barrier repair because epidermal and SC characteristics mimic more closely the native human skin than the ex vivo skin model cultured at 32 °C. Potentially, this model can be used for testing formulations for skin barrier repair. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

[Study of skin retraction applied to the treatment of skin tumors. Mapping of the human body].

PubMed

Dumas, P; Benatar, M; Cardot-Leccia, N; Lebreton, E; Chignon-Sicard, B

2012-04-01

Skin, the main organ of the human body, is equipped with own biomechanical characteristics, highly variable depending on intra-individual factors (location, weight status, dermatological diseases…) and interindividual (age, sex…). Despite some recent cutometric studies, our review of the literature shows that there is no currently reliable analytical model representing the biomechanical behavior of the skin. Yet, this is a central issue in dermatology surgery, especially in the treatment of skin tumors, for the proper observance of surgical margins. We studied prospectively on 75 resection specimens (about 71 patient(s)), for the treatment of skin lesions tumor suspicious or known malignant or benign. Room dimensions were measured before and 5 minutes after excision, leading us to calculate a ratio of retraction of the skin surface. This retraction was correlated with age, gender, tumor type, and anatomic location of the site of excision. The power of retraction of the skin varies significantly by region of the body. It is maximum in the upper limb (hand excluded) and in the cervical region. At the cephalic region, skin of the ear and periorbital skin have capacities of important early retraction. Unlike the lower limb (foot excluded), the back skin of the nose and face appear to be a minimum of shrinkage. Age also seems to change on that capacity shrinkage, sex would have no influence. Our study confirms the variations in the ability of skin retraction based on a number of factors. In dermato-oncology, that power retraction could cause significant differences between clinical surgical margins and final pathologist margins. We believe it must be taken into account by the couple surgeon-pathologist, especially in the context of invasive and/or recurrent tumors. Copyright © 2012. Published by Elsevier SAS.

The top skin-associated genes: a comparative analysis of human and mouse skin transcriptomes.

PubMed

Gerber, Peter Arne; Buhren, Bettina Alexandra; Schrumpf, Holger; Homey, Bernhard; Zlotnik, Albert; Hevezi, Peter

2014-06-01

The mouse represents a key model system for the study of the physiology and biochemistry of skin. Comparison of skin between mouse and human is critical for interpretation and application of data from mouse experiments to human disease. Here, we review the current knowledge on structure and immunology of mouse and human skin. Moreover, we present a systematic comparison of human and mouse skin transcriptomes. To this end, we have recently used a genome-wide database of human gene expression to identify genes highly expressed in skin, with no, or limited expression elsewhere - human skin-associated genes (hSAGs). Analysis of our set of hSAGs allowed us to generate a comprehensive molecular characterization of healthy human skin. Here, we used a similar database to generate a list of mouse skin-associated genes (mSAGs). A comparative analysis between the top human (n=666) and mouse (n=873) skin-associated genes (SAGs) revealed a total of only 30.2% identity between the two lists. The majority of shared genes encode proteins that participate in structural and barrier functions. Analysis of the top functional annotation terms revealed an overlap for morphogenesis, cell adhesion, structure, and signal transduction. The results of this analysis, discussed in the context of published data, illustrate the diversity between the molecular make up of skin of both species and grants a probable explanation, why results generated in murine in vivo models often fail to translate into the human.

Elastic wave induced by friction as a signature of human skin ageing and gender effect.

PubMed

Djaghloul, M; Morizot, F; Zahouani, H

2016-08-01

In this work, we propose an innovative approach based on a rotary tribometer coupled with laser velocimetry for measuring the elastic wave propagation on the skin. The method is based on a dynamic contact with the control of the normal force (Fn ), the contact length and speed. During the test a quantification of the friction force is produced. The elastic wave generated by friction is measured at the surface of the skin 35 mm from the source of friction exciter. In order to quantify the spectral range and the energy property of the wave generated, we have used laser velocimetry whose spot laser diameter is 120 μm, which samples the elastic wave propagation at a frequency which may reach 100 kHz. In this configuration, the speaker is the friction exciter and the listener the laser velocimetry. In order to perform non-invasive friction tests, the normal stress has been set to 0.3 N and the rotary velocity to 3 revolutions per second, which involves a sliding velocity of 63 mm/s. This newly developed innovative tribometer has been used for the analysis of the elastic wave propagation induced by friction on human skin during chronological ageing and gender effect. Measurements in vivo have been made on 60 healthy men and women volunteers, aged from 25 to 70. The results concerning the energy of the elastic wave signature induced by friction show a clear difference between the younger and older groups in the range of a low band of frequencies (0-200 Hz). The gender effect was marked by a 20% decrease in the energy of elastic wave propagation in the female group. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Deep Tissue Injury in Development of Pressure Ulcers: A Decrease of Inflammasome Activation and Changes in Human Skin Morphology in Response to Aging and Mechanical Load

PubMed Central

Stojadinovic, Olivera; Minkiewicz, Julia; Sawaya, Andrew; Bourne, Jonathan W.; Torzilli, Peter; de Rivero Vaccari, Juan Pablo; Dietrich, W. Dalton; Keane, Robert W.; Tomic-Canic, Marjana

2013-01-01

Molecular mechanisms leading to pressure ulcer development are scarce in spite of high mortality of patients. Development of pressure ulcers that is initially observed as deep tissue injury is multifactorial. We postulate that biomechanical forces and inflammasome activation, together with ischemia and aging, may play a role in pressure ulcer development. To test this we used a newly-developed bio-mechanical model in which ischemic young and aged human skin was subjected to a constant physiological compressive stress (load) of 300 kPa (determined by pressure plate analyses of a person in a reclining position) for 0.5–4 hours. Collagen orientation was assessed using polarized light, whereas inflammasome proteins were quantified by immunoblotting. Loaded skin showed marked changes in morphology and NLRP3 inflammasome protein expression. Sub-epidermal separations and altered orientation of collagen fibers were observed in aged skin at earlier time points. Aged skin showed significant decreases in the levels of NLRP3 inflammasome proteins. Loading did not alter NLRP3 inflammasome proteins expression in aged skin, whereas it significantly increased their levels in young skin. We conclude that aging contributes to rapid morphological changes and decrease in inflammasome proteins in response to tissue damage, suggesting that a decline in the innate inflammatory response in elderly skin could contribute to pressure ulcer pathogenesis. Observed morphological changes suggest that tissue damage upon loading may not be entirely preventable. Furthermore, newly developed model described here may be very useful in understanding the mechanisms of deep tissue injury that may lead towards development of pressure ulcers. PMID:23967056

Topical stabilized retinol treatment induces the expression of HAS genes and HA production in human skin in vitro and in vivo.

PubMed

Li, Wen-Hwa; Wong, Heng-Kuan; Serrano, José; Randhawa, Manpreet; Kaur, Simarna; Southall, Michael D; Parsa, Ramine

2017-05-01

Skin Aging manifests primarily with wrinkles, dyspigmentations, texture changes, and loss of elasticity. During the skin aging process, there is a loss of moisture and elasticity in skin resulting in loss of firmness finally leading to skin sagging. The key molecule involved in skin moisture is hyaluronic acid (HA), which has a significant water-binding capacity. HA levels in skin decline with age resulting in decrease in skin moisture, which may contribute to loss of firmness. Clinical trials have shown that topically applied ROL effectively reduces wrinkles and helps retain youthful appearance. In the current study, ROL was shown to induce HA production and stimulates the gene expression of all three forms of hyaluronic acid synthases (HAS) in normal human epidermal keratinocytes monolayer cultures. Moreover, in human skin equivalent tissues and in human skin explants, topical treatment of tissues with a stabilized-ROL formulation significantly induced the gene expression of HAS mRNA concomitant with an increased HA production. Finally, in a vehicle-controlled human clinical study, histochemical analysis confirmed increased HA accumulation in the epidermis in ROL-treated human skin as compared to vehicle. These results show that ROL increases skin expression of HA, a significant contributing factor responsible for wrinkle formation and skin moisture, which decrease during aging. Taken together with the activity to increase collagen, elastin, and cell proliferation, these studies establish that retinol provides multi-functional activity for photodamaged skin.

Genetic polymorphisms and skin aging: the identification of population genotypic groups holds potential for personalized treatments

PubMed Central

Naval, Jordi; Alonso, Vicente; Herranz, Miquel Angel

2014-01-01

Introduction Skin changes are among the most visible signs of aging. Skin properties such as hydration, elasticity, and antioxidant capacity play a key role in the skin aging process. Skin aging is a complex process influenced by heritable and environmental factors. Recent studies on twins have revealed that up to 60% of the skin aging variation between individuals can be attributed to genetic factors, while the remaining 40% is due to non-genetic factors. Recent advances in genomics and bioinformatics approaches have led to the association of certain single nucleotide polymorphisms (SNPs) to skin properties. Our aim was to classify individuals based on an ensemble of multiple polymorphisms associated with certain properties of the skin for providing personalized skin care and anti-aging therapies. Methods and results We identified the key proteins and SNPs associated with certain properties of the skin that contribute to skin aging. We selected a set of 13 SNPs in gene coding for these proteins which are potentially associated with skin aging. Finally, we classified a sample of 120 female volunteers into ten clusters exhibiting different skin properties according to their genotypic signature. Conclusion This is the first study that describes the actual frequency of genetic polymorphisms and their distribution in clusters involved in skin aging in a Caucasian population. Individuals can be divided into genetic clusters defined by genotypic variables. These genotypic variables are linked with polymorphisms in one or more genes associated with certain properties of the skin that contribute to a person’s perceived age. Therefore, by using this classification, it is possible to characterize human skin care and anti-aging needs on the basis of an individual’s genetic signature, thus opening the door to personalized treatments addressed at specific populations. This is part of an ongoing effort towards personalized anti-aging therapies combining genetic signatures

Automation Diagnosis of Skin Disease in Humans using Dempster-Shafer Method

NASA Astrophysics Data System (ADS)

Khairina, Dyna Marisa; Hatta, Heliza Rahmania; Rustam; Maharani, Septya

2018-02-01

Skin disease is an infectious disease that is common in people of all ages. Disorders of the skin often occur because there are factors, among others, are climate, environment, shelter, unhealthy living habits, allergies and others. Skin diseases in Indonesia are mostly caused by bacterial, fungal, parasitic, and allergies. The objective of the research is to diagnose skin diseases in humans by using the method of making decision tree then performing the search by forward chaining and calculating the probability value of Dempster-Shafer method. The results of research in the form of an automated system that can resemble an expert in diagnosing skin disease accurately and can help in overcoming the problem of skin diseases.

Enhancement of human skin facial revitalization by moringa leaf extract cream

PubMed Central

Akhtar, Naveed; Chowdhary, Farzana

2014-01-01

Introduction Solar ultraviolet exposure is the main cause of skin damage by initiation of reactive oxygen species (ROS) leading to skin collagen imperfection and eventually skin roughness. This can be reduced by proper revitalization of skin enhancing younger and healthier appearance. Aim To evaluate the skin facial revitalization effect of a cream formulation containing the Moringa oleifera leaf extract on humans. Material and methods Active cream containing 3% of the concentrated extract of moringa leaves was developed by entrapping in the inner aqueous phase of cream. Base contained no extract. Skin revitalizing parameters, i.e. surface, volume, texture parameters and surface evaluation of the living skin (SELS) were assessed comparatively after application of the base and active cream on human face using Visioscan® VC 98 for a period of 3 months. Results Surface values were increased by the base and decreased by the active cream. Effects produced for the base and active cream were significant and insignificant, respectively, as observed in the case of surface. Unlike the base, the active cream showed significant effects on skin volume, texture parameters (energy, variance and contrast) and SELS, SEr (skin roughness), SEsc (skin scaliness), SEsm (skin smoothness), and SEw (skin wrinkles) parameters. Conclusions The results suggested that moringa cream enhances skin revitalization effect and supports anti-aging skin effects. PMID:25097471

Ameliorating Effect of Akebia quinata Fruit Extracts on Skin Aging Induced by Advanced Glycation End Products

PubMed Central

Shin, Seoungwoo; Son, Dahee; Kim, Minkyung; Lee, Seungjun; Roh, Kyung-Baeg; Ryu, Dehun; Lee, Jongsung; Jung, Eunsun; Park, Deokhoon

2015-01-01

The accumulation of free radicals and advanced glycation end products (AGEs) in the skin plays a very important role in skin aging. Both are known to interact with each other. Therefore, natural compounds or extracts that possess both antioxidant and antiglycation activities might have great antiageing potential. Akebia quinata fruit extract (AQFE) has been used to treat urinary tract inflammatory disease in traditional Korean and Chinese medicines. In the present study, AQFE was demonstrated to possess antioxidant and antiglycation activity. AQFE protects human dermal fibroblasts (HDFs) from oxidative stress and inhibits cellular senescence induced by oxidative stress. We also found that AQFE inhibits glycation reaction between BSA and glucose. The antiglycation activity of AQFE was dose-dependent. In addition, the antiglycation activity of AQFE was confirmed in a human skin explant model. AQFE reduced CML expression and stimulated fibrillin-1 expression in comparison to the methyglyoxal treatment. In addition, the possibility of the extract as an anti-skin aging agent has also been clinically validated. Our analysis of the crow’s feet wrinkle showed that there was a decrease in the depth of deep furrows in RI treated with AQFE cream over an eight-week period. The overall results suggest that AQFE may work as an anti-skin aging agent by preventing oxidative stress and other complications associated with AGEs formation. PMID:26569300

Cytoprotective Polyphenols Against Chronological Skin Aging and Cutaneous Photodamage.

PubMed

Davinelli, Sergio; Bertoglio, Juan Carlos; Polimeni, Ascanio; Scapagnini, Giovanni

2018-01-01

Skin aging is a complex biological process influenced by a combination of intrinsic and extrinsic factors, leading to cumulative alterations of skin structure, function and appearance. Polyphenols, which are secondary plant metabolites, represent one of the largest classes of compounds used in dermatology and nutricosmetics to combat skin aging. The main objective is to provide an overview of the existing literature linking skin aging and the ability of polyphenols as regulatory elements able to maintain skin homeostasis. In this review, we discuss recent progress in understanding the molecular bases of skin aging, with specific emphasis on some well known and extensively studied polyphenols which have significant anti-aging influences and photoprotective effects. Although no relevant clinical data exist and standard delivery systems have not been established, promising results have been obtained in many in vitro and animal models. A wide variety of polyphenols may minimize mechanisms underlying the functional manifestations of photoaging and chronological skin aging. Polyphenols exert their influence mostly through their antioxidant and anti-inflammatory effects, thereby abrogating collagen degradation and/or increasing procollagen synthesis. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Reconstruction of living bilayer human skin equivalent utilizing human fibrin as a scaffold.

PubMed

Mazlyzam, A L; Aminuddin, B S; Fuzina, N H; Norhayati, M M; Fauziah, O; Isa, M R; Saim, L; Ruszymah, B H I

2007-05-01

Our aim of this study was to develop a new methodology for constructing a bilayer human skin equivalent to create a more clinical compliance skin graft composite for the treatment of various skin defects. We utilized human plasma derived fibrin as the scaffold for the development of a living bilayer human skin equivalent: fibrin-fibroblast and fibrin-keratinocyte (B-FF/FK SE). Skin cells from six consented patients were culture-expanded to passage 1. For B-FF/FK SE formation, human fibroblasts were embedded in human fibrin matrix and subsequently another layer of human keratinocytes in human fibrin matrix was stacked on top. The B-FF/FK SE was then transplanted to athymic mice model for 4 weeks to evaluate its regeneration and clinical performance. The in vivo B-FF/FK SE has similar properties as native human skin by histological analysis and expression of basal Keratin 14 gene in the epidermal layer and Collagen type I gene in the dermal layer. Electron microscopy analysis of in vivo B-FF/FK SE showed well-formed and continuous epidermal-dermal junction. We have successfully developed a technique to engineer living bilayer human skin equivalent using human fibrin matrix. The utilization of culture-expanded human skin cells and fibrin matrix from human blood will allow a fully autologous human skin equivalent construction.

Skin Aging: MedlinePlus Health Topic

MedlinePlus

... Specifics Bags Under Eyes (Mayo Foundation for Medical Education and Research) Also in Spanish Sagging Skin (American Society for Dermatologic Surgery) Clinical Trials ClinicalTrials.gov: Skin Aging (National Institutes of Health) Journal Articles References and abstracts from MEDLINE/PubMed (National ...

Proposed shade guide for human facial skin and lip: a pilot study.

PubMed

Wee, Alvin G; Beatty, Mark W; Gozalo-Diaz, David J; Kim-Pusateri, Seungyee; Marx, David B

2013-08-01

Currently, no commercially available facial shade guide exists in the United States for the fabrication of facial prostheses. The purpose of this study was to measure facial skin and lip color in a human population sample stratified by age, gender, and race. Clustering analysis was used to determine optimal color coordinates for a proposed facial shade guide. Participants (n=119) were recruited from 4 racial/ethnic groups, 5 age groups, and both genders. Reflectance measurements of participants' noses and lower lips were made by using a spectroradiometer and xenon arc lamp with a 45/0 optical configuration. Repeated measures ANOVA (α=.05), to identify skin and lip color differences, resulting from race, age, gender, and location, and a hierarchical clustering analysis, to identify clusters of skin colors) were used. Significant contributors to L*a*b* facial color were race and facial location (P<.01). b* affected all factors (P<.05). Age affected only b* (P<.001), while gender affected only L* (P<.05) and b* (P<.05). Analyses identified 5 clusters of skin color. The study showed that skin color caused by age and gender primarily occurred within the yellow-blue axis. A significant lightness difference between gender groups was also found. Clustering analysis identified 5 distinct skin shade tabs. Copyright © 2013 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Gastrodia elata Blume Extract Modulates Antioxidant Activity and Ultraviolet A-Irradiated Skin Aging in Human Dermal Fibroblast Cells.

PubMed

Song, Eunju; Chung, Haeyon; Shim, Eugene; Jeong, Jung-Ky; Han, Bok-Kyung; Choi, Hyuk-Joon; Hwang, Jinah

2016-11-01

Gastrodia elata Blume (GEB), a traditional herbal medicine, has been used to treat a wide range of neurological disorders (e.g., paralysis and stroke) and skin problems (e.g., atopic dermatitis and eczema) in oriental medicine. This study was designed to investigate the antioxidant ability of GEB and its antiaging effect on human dermal fibroblast cells (HDF). The total phenolic and flavonoid contents of GEB were 21.8 and 0.43 mg/g dry weight (DW), respectively. The ergothioneine content of GEB was 0.41 mg/mL DW. The DPPH and ABTS radical scavenging activities of GEB at 5 and 10 mg/mL approximately ranged between 31% and 44%. The superoxide dismutase activity of GEB at 10 and 25 mg/mL was 57% and 76%, respectively. GEB increased procollagen type 1 (PC1) production and inhibited matrix metalloproteinase-1 (MMP-1) production and elastase-1 activity in UVA-irradiated HDF. PC1 messenger RNA (mRNA) levels decreased upon UVA irradiation, but recovered in response to high doses of GEB in HDF. On the contrary, GEB significantly decreased MMP-1 and elastase-1 mRNA levels, which were markedly induced in UVA-irradiated HDF. Collectively, these results suggest that GEB has sufficient antioxidant ability to prevent the signs of skin aging in UVA-irradiated human skin cells, suggesting its potential as a natural antiaging product.

Skin intervention of fullerene-integrated nanoemulsion in structural and collagen regeneration against skin aging.

PubMed

Ngan, Cheng Loong; Basri, Mahiran; Tripathy, Minaketan; Abedi Karjiban, Roghayeh; Abdul-Malek, Emilia

2015-04-05

Despite the fact that intrinsic oxidative stress is inevitable, the extrinsic factor such as ultraviolet radiation enhances reactive oxygen species (ROS) generation resulting in premature skin aging. Nanoemulsion was loaded with fullerene, a strong free radical scavenger, and its efficacy to provide protection and regenerative effect against ROS-induced collagen breakdown in human skin was studied. Stable fullerene nanoemulsions were formulated using high shear homogenization and ultrasonic dispersion technique. An open trial was conducted using fullerene nanoemulsion on skin twice a day for 28 days. The mean collagen score significantly increased (P<0.05) from 36.53±4.39 to 48.69±5.46 with 33.29% increment at the end of the treatment. Biophysical characteristics of skin revealed that skin hydration was increased significantly (P<0.05) from 40.91±7.01 to 58.55±6.08 corneometric units (43.12% increment) and the water was able to contain within the stratum corneum without any increased in transepidermal water loss. In the in vitro safety evaluation, fullerene nanoemulsion showed no acute toxicity on 3T3 fibroblast cell line for 48h and no indication of potential dermal irritation. Hence, the fullerene nanoemulsion may assist in protecting collagen from breakdown with cosmeceutical benefit. Copyright © 2015 Elsevier B.V. All rights reserved.

Using FLIM in the study of permeability barrier function of aged and young skin

NASA Astrophysics Data System (ADS)

Xu, P.; Choi, E. H.; Man, M. Q.; Crumrine, D.; Mauro, T.; Elias, P.

2006-02-01

Aged skin commonly is afflicted by inflammatory skin diseases or xerosis/eczema that can be triggered or exacerbated by impaired epidermal permeability barrier homeostasis. It has been previously described a permeability barrier defect in humans of advanced age (> 75 years), which in a murine analog >18 mos, could be attributed to reduced lipid synthesis synthesis. However, the functional abnormality in moderately aged mice is due not to decreased lipid synthesis, but rather to a specific defect in stratum corneum (SC) acidification causing impaired lipid processing processing. Endogenous Na +/H + antiporter (NHE1) level was found declined in moderately aged mouse epidermis. This acidification defect leads to perturbed permeability barrier homeostasis through more than one pathways, we addressed suboptimal activation of the essential, lipid-processing enzyme, β-glucocerebrosidase (BGC) is linked to elevated SC pH. Finally, the importance of the epidermis acidity is shown by the normalization of barrier function after exogenous acidification of moderately aged skin.

Modeling of Light Reflection from Human Skin

NASA Astrophysics Data System (ADS)

Delgado, J. A.; Cornejo, A.; Rivas-Silva, J. F.; Rodríguez, E. E.

2006-09-01

In this work a two-layer model is used to simulate the spectral reflectance of adult human skin. We report and discuss diffuse reflectance spectra of this model for three values of the volume fraction of melanosomes fme, namely a) lightly pigmented skin fme = 4%, b) moderately pigmented skin fme = 14% and c) heavily pigmented skin fme = 30% at a volume fraction of blood fbl = 0.2%. We also considered the modeling of reflectance spectra for two values of fbl (0.2% and 1%) with fme = 4%. Both simulations were done in the 400-700 nm spectral range using the Monte Carlo simulation code MCML in standard C. Results showed that the principal signatures of human skin reflectance spectrum are obtained with this model and that it could be of valuable use to made predictions of diffuse reflectance of human skin for different values of the parameters related to skin characterization. These parameters can be associated to distinct medical conditions, such as erythema, jaundice, etc.

The skin aging index: a new approach for documenting anti-aging products or procedures.

PubMed

Nkengne, Alex; Roure, Romain; Rossi, Ana Beatriz; Bertin, Christiane

2013-08-01

The overall appearance of an aged skin is characterized by a combination of several attributes such as wrinkles, brown spots and sagging. Our objective was to develop and validate a statistical framework to assess the overall anti-ageing benefits of products/procedures. Different skin attributes were evaluated by a clinical grader and combined using a Principal Component Analysis (PCA). The Skin Ageing Index was defined as the normalized projection of the clinical grading values on the first PCA axis. Several Skin Indexes were built by grouping specific parameters related to a skin condition such as overall ageing, wrinkles and sagging. The method was validated following two steps. Firstly, a clinical study was performed on 173 Caucasian women and the correlation between the Skin Indexes and the volunteers' real and perceived age was estimated. Secondly, a double-blinded placebo-controlled randomized study was performed on 87 Caucasian women to assess the efficacy of an anti-wrinkle cream containing retinol, hyaluronic acid and dihydroxymethylchromone. Facial wrinkles were clinically evaluated and a Wrinkle Index was built. All indexes were highly correlated with the real and the perceived age (0.57 ≤ Pearson R ≤ 0.92, P-value ≤ 0.05). Finally, the Wrinkle Index provides documented evidence that the tested product significantly reduced the appearance of wrinkles versus the placebo and the baseline assessment (-23.53% after 4 weeks, -27.83% after 8 weeks). Skin ageing Indexes capture information relevant to the visual transformation of facial skin with age, while providing documented product benefits. These tools may enable a simpler and more consistent comparison of anti-ageing products/procedures. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Influence of skin ageing features on Chinese women's perception of facial age and attractiveness.

PubMed

Porcheron, A; Latreille, J; Jdid, R; Tschachler, E; Morizot, F

2014-08-01

Ageing leads to characteristic changes in the appearance of facial skin. Among these changes, we can distinguish the skin topographic cues (skin sagging and wrinkles), the dark spots and the dark circles around the eyes. Although skin changes are similar in Caucasian and Chinese faces, the age of occurrence and the severity of age-related features differ between the two populations. Little is known about how the ageing of skin influences the perception of female faces in Chinese women. The aim of this study is to evaluate the contribution of the different age-related skin features to the perception of age and attractiveness in Chinese women. Facial images of Caucasian women and Chinese women in their 60s were manipulated separately to reduce the following skin features: (i) skin sagging and wrinkles, (ii) dark spots and (iii) dark circles. Finally, all signs were reduced simultaneously (iv). Female Chinese participants were asked to estimate the age difference between the modified and original images and evaluate the attractiveness of modified and original faces. Chinese women perceived the Chinese faces as younger after the manipulation of dark spots than after the reduction in wrinkles/sagging, whereas they perceived the Caucasian faces as the youngest after the manipulation of wrinkles/sagging. Interestingly, Chinese women evaluated faces with reduced dark spots as being the most attractive whatever the origin of the face. The manipulation of dark circles contributed to making Caucasian and Chinese faces being perceived younger and more attractive than the original faces, although the effect was less pronounced than for the two other types of manipulation. This is the first study to have examined the influence of various age-related skin features on the facial age and attractiveness perception of Chinese women. The results highlight different contributions of dark spots, sagging/wrinkles and dark circles to their perception of Chinese and Caucasian faces. �

The evolution of human skin coloration.

PubMed

Jablonski, N G; Chaplin, G

2000-07-01

Skin color is one of the most conspicuous ways in which humans vary and has been widely used to define human races. Here we present new evidence indicating that variations in skin color are adaptive, and are related to the regulation of ultraviolet (UV) radiation penetration in the integument and its direct and indirect effects on fitness. Using remotely sensed data on UV radiation levels, hypotheses concerning the distribution of the skin colors of indigenous peoples relative to UV levels were tested quantitatively in this study for the first time. The major results of this study are: (1) skin reflectance is strongly correlated with absolute latitude and UV radiation levels. The highest correlation between skin reflectance and UV levels was observed at 545 nm, near the absorption maximum for oxyhemoglobin, suggesting that the main role of melanin pigmentation in humans is regulation of the effects of UV radiation on the contents of cutaneous blood vessels located in the dermis. (2) Predicted skin reflectances deviated little from observed values. (3) In all populations for which skin reflectance data were available for males and females, females were found to be lighter skinned than males. (4) The clinal gradation of skin coloration observed among indigenous peoples is correlated with UV radiation levels and represents a compromise solution to the conflicting physiological requirements of photoprotection and vitamin D synthesis. The earliest members of the hominid lineage probably had a mostly unpigmented or lightly pigmented integument covered with dark black hair, similar to that of the modern chimpanzee. The evolution of a naked, darkly pigmented integument occurred early in the evolution of the genus Homo. A dark epidermis protected sweat glands from UV-induced injury, thus insuring the integrity of somatic thermoregulation. Of greater significance to individual reproductive success was that highly melanized skin protected against UV-induced photolysis of

Relationship between skin color and solar elastosis in aged Asian skin: A colorimetric-pathologic correlation.

PubMed

Kim, Dai Hyun; Oh, Ga Na; Kwon, In Hyuk; Seo, Soo Hong; Kye, Young Chul; Ahn, Hyo Hyun

2017-10-01

Aged skin is reported to be associated with unattractive skin color changes and solar elastosis. However, comparative studies have not documented the possible correlation between the two factors. This study investigated the plausible relationship between the facial skin color of elderly Asians and solar elastosis. A total of 22 skin specimens were collected from 22 Korean patients who underwent cheek skin biopsies. Skin color was quantitatively measured using colorimetric photography techniques to produce CIE L*a*b* values; the degree of solar elastosis was quantifiably assessed using a histologic grading scale. These values were used to investigate a correlation between the CIE L*a*b* coordinates and solar elastosis grade. The solar elastosis grade increased according to patient age (r = 0.67, p = .0006). However, the extent of solar elastosis was not statistically correlated with the CIE L*a*b* values, including L*, a*, and b* (r = 0.02, p = .95; r = 0.15, p = 0.50; r = -0.07, p = 0.76, respectively). The results showed that the solar elastosis grade increased, according to patient age, because of cumulative actinic damage. However, colorimetric skin color data did not correlate with the degree of solar elastosis. Therefore, cutaneous color changes and solar elastosis are separate, age-related phenomena. Physicians should be aware of the possible histologic changes in actinically damaged facial skin, regardless of the skin color. © 2017 Wiley Periodicals, Inc.

Xenobiotic-metabolizing enzymes in the skin of rat, mouse, pig, guinea pig, man, and in human skin models.

PubMed

Oesch, F; Fabian, E; Guth, K; Landsiedel, R

2014-12-01

The exposure of the skin to medical drugs, skin care products, cosmetics, and other chemicals renders information on xenobiotic-metabolizing enzymes (XME) in the skin highly interesting. Since the use of freshly excised human skin for experimental investigations meets with ethical and practical limitations, information on XME in models comes in the focus including non-human mammalian species and in vitro skin models. This review attempts to summarize the information available in the open scientific literature on XME in the skin of human, rat, mouse, guinea pig, and pig as well as human primary skin cells, human cell lines, and reconstructed human skin models. The most salient outcome is that much more research on cutaneous XME is needed for solid metabolism-dependent efficacy and safety predictions, and the cutaneous metabolism comparisons have to be viewed with caution. Keeping this fully in mind at least with respect to some cutaneous XME, some models may tentatively be considered to approximate reasonable closeness to human skin. For dermal absorption and for skin irritation among many contributing XME, esterase activity is of special importance, which in pig skin, some human cell lines, and reconstructed skin models appears reasonably close to human skin. With respect to genotoxicity and sensitization, activating XME are not yet judgeable, but reactive metabolite-reducing XME in primary human keratinocytes and several reconstructed human skin models appear reasonably close to human skin. For a more detailed delineation and discussion of the severe limitations see the "Overview and Conclusions" section in the end of this review.

How much related to skin wrinkles between facial and body site? Age-related changes in skin wrinkle on the knee assessed by skin bioengineering techniques.

PubMed

Yoo, M A; Seo, Y K; Shin, M K; Koh, J S

2016-02-01

Skin aging has been focused the wrinkle on the face than on the body, so most studies have been studied the change in Crow's feet for ages. Only little is known about the age-dependent changes of wrinkles on body sites. The aim of this study was to establish new grading criteria for severity of wrinkles on knees and to investigate the relationship of wrinkle severity with age- and site-dependent. The skin on the knee of 38 healthy Korean female volunteers, divided into two groups young and old, were photographed. Standard photograph for body wrinkle was established (grade 0~7), and then visual assessment, skin wrinkle, and skin elasticity were evaluated on Crow's feet and the knee. We examined for any significant differences and the correlation of skin aging parameters with age and two different sites. Skin wrinkle severity with standard photograph and wrinkle parameters (Ra, Rmax, Rz, and Rv) had a significantly positive correlation with age-dependent on the knee (P < 0.001). Also, skin elastic parameters (R2, R5, R6, R7, and Q1) showed a significant negative correlation with age on the knee (P < 0.001). Skin wrinkle severity with standard photograph was highly correlated with all skin wrinkle parameters and skin elastic parameters (R2, R5, R7, and Q1) on the knee (P < 0.001). In addition, all the skin aging parameters on the knee were significantly correlated with Crow's feet (P < 0.01). Skin aging on the knee had the same tendency as the Crow's feet. This study has shown the new grading criteria of wrinkles on the knee. Skin wrinkle and elasticity on the knee are age-dependent related and aging on the knee is highly related to Crow's feet. Those parameters are using a quantitative method to evaluate body aging. Also, the knee is considered that it could be a suitable site to evaluate body aging. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Cold-induced vasoconstriction at forearm and hand skin sites: the effect of age.

PubMed

Kingma, B R M; Frijns, A J H; Saris, W H M; van Steenhoven, A A; van Marken Lichtenbelt, W D

2010-07-01

During mild cold exposure, elderly are at risk of hypothermia. In humans, glabrous skin at the hands is well adapted as a heat exchanger. Evidence exists that elderly show equal vasoconstriction due to local cooling at the ventral forearm, yet no age effects on vasoconstriction at hand skin have been studied. Here, we tested the hypotheses that at hand sites (a) elderly show equal vasoconstriction due to local cooling and (b) elderly show reduced response to noradrenergic stimuli. Skin perfusion and mean arterial pressure were measured in 16 young adults (Y: 18-28 years) and 16 elderly (E: 68-78 years). To study the effect of local vasoconstriction mechanisms local sympathetic nerve terminals were blocked by bretylium (BR). Baseline local skin temperature was clamped at 33 degrees C. Next, local temperature was reduced to 24 degrees C. After 15 min of local cooling, noradrenaline (NA) was administered to study the effect of neural vasoconstriction mechanisms. No significant age effect was observed in vasoconstriction due to local cooling at BR sites. After NA, vasoconstriction at the forearm showed a significant age effect; however, no significant age effect was found at the hand sites. [Change in CVC (% from baseline): Forearm Y: -76 +/- 3 vs. E: -60 +/- 5 (P < 0.01), dorsal hand Y: -74 +/- 4 vs. E: -72 +/- 4 (n.s.), ventral hand Y: -80 +/- 7 vs. E: -70 +/- 11 (n.s.)]. In conclusion, in contrast to results from the ventral forearm, elderly did not show a blunted response to local cooling and noradrenaline at hand skin sites. This indicates that at hand skin the noradrenergic mechanism of vasoconstriction is maintained with age.

Ex vivo study of the home-use TriPollar RF device using an experimental human skin model.

PubMed

Boisnic, Sylvie; Branchet, Marie Christine

2010-09-01

A wide variety of professional radio frequency (RF) aesthetic treatments for anti-aging are available aiming at skin tightening. A new home-use RF device for facial treatments has recently been developed based on TriPollar technology. To evaluate the mechanism of the new home-use device, in the process of collagen remodeling, using an ex vivo skin model. Human skin samples were collected in order to evaluate the anti-aging effect of a home-use device for facial treatments on an ex vivo human skin model. Skin tightening was evaluated by dermal histology, quantitative analysis of collagen fibers and dosage of collagen synthesis. Significant collagen remodeling following RF treatment with the device was found in the superficial and mid-deep dermis. Biochemical measurement of newly synthesized collagen showed an increase of 41% in the treated samples as compared to UV-aged control samples. The new home-use device has been demonstrated to affect significant collagen remodeling, in terms of the structural and biochemical improvement of dermal collagen on treated skin samples.

Volumetric Visualization of Human Skin

NASA Astrophysics Data System (ADS)

Kawai, Toshiyuki; Kurioka, Yoshihiro

We propose a modeling and rendering technique of human skin, which can provide realistic color, gloss and translucency for various applications in computer graphics. Our method is based on volumetric representation of the structure inside of the skin. Our model consists of the stratum corneum and three layers of pigments. The stratum corneum has also layered structure in which the incident light is reflected, refracted and diffused. Each layer of pigment has carotene, melanin or hemoglobin. The density distributions of pigments which define the color of each layer can be supplied as one of the voxel values. Surface normals of upper-side voxels are fluctuated to produce bumps and lines on the skin. We apply ray tracing approach to this model to obtain the rendered image. Multiple scattering in the stratum corneum, reflective and absorptive spectrum of pigments are considered. We also consider Fresnel term to calculate the specular component for glossy surface of skin. Some examples of rendered images are shown, which can successfully visualize a human skin.

Effects of tretinoin on wound healing in aged skin.

PubMed

de Campos Peseto, Danielle; Carmona, Erica Vilaça; Silva, Kellyn Cristina da; Guedes, Flavia Roberta Valente; Hummel Filho, Fernando; Martinez, Natalia Peres; Pereira, José Aires; Rocha, Thalita; Priolli, Denise Gonçalves

2016-03-01

Aged and adult populations have differences in the structural, biological, and healing properties of skin. Comparative studies of healing under the influence of retinoids in both these populations are very important and, to the best of our knowledge, have not been performed to date. The purpose of this study was to compare the activities of topical tretinoin in aged and adult animal models of wound healing by secondary intention. Male aged rats (24 months old, n = 7) and adult rats (6 months old, n = 8) were used. The rats were assigned to the following groups according to the dates on which wound samples were excised (day 14 or 21 after model creation): treated group, control group, and naive group. Topical application of tretinoin cream was used only on the proximal wound and was applied daily for 7 days. Wound healing areas were measured using metal calipers, and morphological analysis was performed. Slides were stained with Hematoxylin and Eosin, Masson's trichrome, and periodic acid-Schiff stains. Statistical analysis adopted a 5% coefficient for rejection of the null hypothesis. Although aged animals showed skin repair, complete reepithelialization was found on day 21 in some animals of both groups (treated and control). In aged rats, the wound area was significantly smaller in treated wounds than in untreated wounds, resulting in a larger scar area compared with the adult group. When treated wounds were compared, no differences were found between the wound areas in adult and aged rats. As expected, the collagen concentration was higher in normal skin from adult rats than in normal skin from aged animals, but there was no difference when aged skin was treated with tretinoin. These results indicate that tretinoin increases collagen synthesis in aged skin and returns the healing process to a normal state of skin healing. © 2016 by the Wound Healing Society.

Modulation of gene expression as a new skin anti-aging strategy.

PubMed

Talbourdet, Sylvie; Sadick, Neil S; Lazou, Kristell; Bonnet-Duquennoy, Mathilde; Kurfurst, Robin; Neveu, Michele; Heusèle, Catherine; André, Patrice; Schnebert, Sylvianne; Draelos, Zoe D; Perrier, Eric

2007-06-01

[corrected] The signs of aging may originate from natural processes or from exposure to the sun, wind, or other environmental factors. To evaluate the anti-aging effects of potential agents researchers must first identify and be able to quantify epidermal markers that change with aging. This paper summarizes the results of studies conducted to evaluate the transcriptional effects of an Aframomum angustifolium seed extract and Malva Sylvestris extract, and the antiaging efficacy of a skin care product containing the Aframomum angustifolium seed extract. The transcriptional effect of an Aframomum angustifolium seed extract on normal human keratinocytes (NHKs) and normal human fibroblasts (NHF) was evaluated in vitro with the use of a low-density DNA array technology. The Malva Sylvestris extract was studied with a commercial DNA macroarray and by a real-time quantitative reverse transcriptase-polymerase chain reaction. The in vitro anti-aging activities of the Malva sylvestris extract were compared with those of all-trans retinoic acid (RA), a well-established topical therapy for photodamage and wrinkles. The genes studied were known to be modified by RA. The anti-aging efficacy of a facial skin care product containing Aframomum angustifolium seed extract was evaluated in a single-center study using image processing analysis and in a 2-center study by evaluation of the photographs by the investigator, independent evaluators, and subjects. In general, the Aframomum angustifolium seed extract strongly modified the gene expression profiles of NHKs and weakly modified the gene expression profiles of NHFs. After incubation with Aframomum angustifolium seed extract, the expressions of 3 antioxidant genes (metallothionein 1, metallothionein 2, and thioredoxin) were increased in NHKs, while expressions of 1 antioxidant gene (glutathione peroxidase) was increased in NHFs. Concerning the Malva sylvestris extract, a cDNA macro-array technology experiment with the reconstructed

Mitochondrial damage and ageing using skin as a model organ.

PubMed

Hudson, Laura; Bowman, Amy; Rashdan, Eyman; Birch-Machin, Mark A

2016-11-01

Ageing describes the progressive functional decline of an organism over time, leading to an increase in susceptibility to age-related diseases and eventually to death, and it is a phenomenon observed across a wide range of organisms. Despite a vast repertoire of ageing studies performed over the past century, the exact causes of ageing remain unknown. For over 50 years it has been speculated that mitochondria play a key role in the ageing process, due mainly to correlative data showing an increase in mitochondrial dysfunction, mitochondrial DNA (mtDNA) damage, and reactive oxygen species (ROS) with age. However, the exact role of the mitochondria in the ageing process remains unknown. The skin is often used to study human ageing, due to its easy accessibility, and the observation that the ageing process is able to be accelerated in this organ via environmental insults, such as ultra violet radiation (UVR). This provides a useful tool to investigate the mechanisms regulating ageing and, in particular, the role of the mitochondria. Observations from dermatological and photoageing studies can provide useful insights into chronological ageing of the skin and other organs such as the brain and liver. Moreover, a wide range of diseases are associated with ageing; therefore, understanding the cause of the ageing process as well as regulatory mechanisms involved could provide potentially advantageous therapeutic targets for the prevention or treatment of such diseases. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Effect of Age on Tooth Shade, Skin Color and Skin-Tooth Color Interrelationship in Saudi Arabian Subpopulation.

PubMed

Haralur, Satheesh B

2015-08-01

Dental restoration or prosthesis in harmony with adjacent natural teeth color is indispensable part for the successful esthetic outcome. The studies indicate is existence of correlation between teeth and skin color. Teeth and skin color are changed over the aging process. The aim of the study was to explore the role of age on the tooth and skin color parameters, and to investigate the effect of ageing on teeth-skin color correlation. Total of 225 Saudi Arabian ethnic subjects was divided into three groups of 75 each. The groups were divided according to participant's age. The participant's age for Group I, Group II, and Group III was 18-29 years, 30-50 years, and above 50 years, respectively. The tooth color was identified by spectrophotometer in CIE Lab parameters. The skin color was registered with skin surface photography. The data were statistically analyzed with one-way ANOVA and correlation tests with SPSS 18 software. The Group I had the highest 'L' value of 80.26, Group III recorded the least value of 76.66. The Group III had highest yellow value 'b' at 22.72, while Group I had 19.19. The skin 'L' value was highest in the young population; the elder population had the increased red value 'a' in comparison to younger subjects. The 'L' tooth color parameter had a strong positive linear correlation with skin color in young and adult subjects. While Group III teeth showed the strong positive correlation with 'b' parameter at malar region. The elder subjects had darker and yellow teeth in comparison with younger subjects. The reddening of the skin was observed as age-related skin color change. The age had a strong influence on the teeth-skin color correlation.

Photoprotection of human skin beyond ultraviolet radiation.

PubMed

Grether-Beck, Susanne; Marini, Alessandra; Jaenicke, Thomas; Krutmann, Jean

2014-01-01

Photoprotection of human skin by means of sunscreens or daily skin-care products is traditionally centered around the prevention of acute (e.g. sunburn) and chronic (e.g. skin cancer and photoaging) skin damage that may result from exposure to ultraviolet rays (UVB and UVA). Within the last decade, however, it has been appreciated that wavelengths beyond the ultraviolet spectrum, in particular visible light and infrared radiation, contribute to skin damage in general and photoaging of human skin in particular. As a consequence, attempts have been made to develop skin care/sunscreen products that not only protect against UVB or UVA radiation but provide photoprotection against visible light and infrared radiation as well. In this article, we will briefly review the current knowledge about the mechanisms responsible for visible light/infrared radiation-induced skin damage and then, based on this information, discuss strategies that have been successfully used or may be employed in the future to achieve photoprotection of human skin beyond ultraviolet radiation. In this regard we will particularly focus on the use of topical antioxidants and the challenges that result from the task of showing their efficacy. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Solar ultraviolet irradiation induces decorin degradation in human skin likely via neutrophil elastase.

PubMed

Li, Yong; Xia, Wei; Liu, Ying; Remmer, Henriette A; Voorhees, John; Fisher, Gary J

2013-01-01

Exposure of human skin to solar ultraviolet (UV) irradiation induces matrix metalloproteinase-1 (MMP-1) activity, which degrades type I collagen fibrils. Type I collagen is the most abundant protein in skin and constitutes the majority of skin connective tissue (dermis). Degradation of collagen fibrils impairs the structure and function of skin that characterize skin aging. Decorin is the predominant proteoglycan in human dermis. In model systems, decorin binds to and protects type I collagen fibrils from proteolytic degradation by enzymes such as MMP-1. Little is known regarding alterations of decorin in response to UV irradiation. We found that solar-simulated UV irradiation of human skin in vivo stimulated substantial decorin degradation, with kinetics similar to infiltration of polymorphonuclear (PMN) cells. Proteases that were released from isolated PMN cells degraded decorin in vitro. A highly selective inhibitor of neutrophil elastase blocked decorin breakdown by proteases released from PMN cells. Furthermore, purified neutrophil elastase cleaved decorin in vitro and generated fragments with similar molecular weights as those resulting from protease activity released from PMN cells, and as observed in UV-irradiated human skin. Cleavage of decorin by neutrophil elastase significantly augmented fragmentation of type I collagen fibrils by MMP-1. Taken together, these data indicate that PMN cell proteases, especially neutrophil elastase, degrade decorin, and this degradation renders collagen fibrils more susceptible to MMP-1 cleavage. These data identify decorin degradation and neutrophil elastase as potential therapeutic targets for mitigating sun exposure-induced collagen fibril degradation in human skin.

Photoprotection by pistachio bioactives in a 3-dimensional human skin equivalent tissue model.

PubMed

Chen, C-Y Oliver; Smith, Avi; Liu, Yuntao; Du, Peng; Blumberg, Jeffrey B; Garlick, Jonathan

2017-09-01

Reactive oxygen species (ROS) generated during ultraviolet (UV) light exposure can induce skin damage and aging. Antioxidants can provide protection against oxidative injury to skin via "quenching" ROS. Using a validated 3-dimensional (3D) human skin equivalent (HSE) tissue model that closely mimics human skin, we examined whether pistachio antioxidants could protect HSE against UVA-induced damage. Lutein and γ-tocopherol are the predominant lipophilic antioxidants in pistachios; treatment with these compounds prior to UVA exposure protected against morphological changes to the epithelial and connective tissue compartments of HSE. Pistachio antioxidants preserved overall skin thickness and organization, as well as fibroblast morphology, in HSE exposed to UVA irradiation. However, this protection was not substantiated by the analysis of the proliferation of keratinocytes and apoptosis of fibroblasts. Additional studies are warranted to elucidate the basis of these discordant results and extend research into the potential role of pistachio bioactives promoting skin health.

Skin permeation and distribution of two sunscreens: a comparison between reconstituted human skin and hairless rat skin.

PubMed

Monti, D; Brini, I; Tampucci, S; Chetoni, P; Burgalassi, S; Paganuzzi, D; Ghirardini, A

2008-01-01

The aims of this work were (a) to develop a simple and reproducible procedure for percutaneous absorption and distribution tests of sunscreens using one human skin culture model (Epiderm 606; reconstructed epidermis, RE), (b) to compare the said model with rat skin (RS) in vitro and (c) to evaluate the effect of different formulations. The cutaneous permeation and distribution of two UV filters, ethylhexylmethoxycinnamate (MC80) and ethylhexyltriazone (T150), using 3 different vehicles were investigated. The permeation studies demonstrated that neither MC80 nor T150 permeated through both RS and RE in spite of different thicknesses of the 2 substrates. Distribution studies demonstrated that sectioning by cryomicrotome to obtain horizontal skin layers was suitable for both RS and RE (apart from its small thickness) with a good reproducibility of data. The amounts of sunscreens retained in the 2 substrates were in the same order of magnitude for all formulations with a greater depot in RS. Different distribution profiles of the tested formulations could be ascribed to the different lipid compositions of RE and RS. Since the physicochemical characteristics of RE are closer to those of human skin, the results obtained with reconstructed human skin models could be suitable to replace human skin in 'in vitro testing'. Copyright 2008 S. Karger AG, Basel.

Autophagy in human skin fibroblasts: Comparison between young and aged cells and evaluation of its cellular rhythm and response to Ultraviolet A radiation.

PubMed

Pernodet, Nadine; Dong, Kelly; Pelle, Edward

2016-01-01

Autophagic mechanisms play critical roles in cell maintenance. Damaged organelles that are not removed by autophagosomes, which act by engulfing and degrading these cellular components, have been linked to various pathologies. Recently, the progression of aging has also been correlated to a compromised autophagic response. Here, we report for the first time a significant reduction in autophagic levels in synchronized aged normal human skin fibroblasts as compared to young fibroblasts. We measured a 77.9% reduction in autophagy as determined by reverse transcription-polymerase chain reaction for LC3B expression, a microtubule-associated protein correlated to late stage autophagosome formation. In addition, we visualized these same changes by immunocytofluorescence with antibodies directed against LC3B. By harvesting synchronized, as well as unsynchronized cells over time, we were also able to measure for the first time a nighttime peak in autophagy that was present in young but absent in aged fibroblasts. Finally, since human skin is constantly subjected to environmentally induced oxidative stress from sunlight, we exposed fibroblasts to 10 J/cm2 ultraviolet A and found, in good agreement with current literature, not only that irradiation could partially reactivate autophagy in the aged cells, but also that this increase was phase shifted earlier from its endogenous temporal pattern because of its loss of synchronization with circadian rhythm.

Two-wavelength Raman detector for noninvasive measurements of carotenes and lycopene in human skin

NASA Astrophysics Data System (ADS)

Ermakov, Igor V.; Ermakova, Maia R.; Gellermann, Werner

2005-04-01

Carotenoids are an important part of the antioxidant system in human skin. Carotenoid molecules, provided by fruits and vegetables, are potent free radical quenchers that accumulate in the body. If not balanced by carotenoids and other antioxidants, free radicals may cause premature skin aging, oxidative cell damage, and even skin cancers. As carotenoids depletion may predispose a person to cancer or other disease, rapid and noninvasive measurement of carotenoid level in skin may be of preventive or diagnostic help. At the very least, such measurement can be used to obtain a biomarker for healthy levels of fruit and vegetable consumption. Recently we have developed noninvasive optical technique based on Raman spectroscopy. In this paper we describe compact optical detector for clinical applications that utilizes two-wavelength excitation. It selectively measures the two most prominent skin carotenoids found in the human skin, lycopene and carotenes. According to the medical literature, these two compounds may play different roles in the human body and be part of different tissue defense mechanisms. Dual-wavelength Raman measurements reveal significant differences in the carotenoid composition of different subjects.

Trends in aging and skin care: Ayurvedic concepts

PubMed Central

Datta, Hema Sharma; Paramesh, Rangesh

2010-01-01

The association between Ayurveda, anti-aging and cosmeceuticals is gaining importance in the beauty, health and wellness sector. Ayurvedic cosmeceuticals date back to the Indus Valley Civilization. Modern research trends mainly revolve around principles of anti-aging activity described in Ayurveda: Vayasthapana (age defying), Varnya (brighten skin-glow), Sandhaniya (cell regeneration), Vranaropana (healing), Tvachya (nurturing), Shothahara (anti-inflammatory), Tvachagnivardhani (strengthening skin metabolism) and Tvagrasayana (retarding aging). Many rasayana plants such as Emblica officinalis (Amla) and Centella asiatica (Gotukola) are extensively used. PMID:21836797

Isolation of Human Skin Dendritic Cell Subsets.

PubMed

Gunawan, Merry; Jardine, Laura; Haniffa, Muzlifah

2016-01-01

Dendritic cells (DCs) are specialized leukocytes with antigen-processing and antigen-presenting functions. DCs can be divided into distinct subsets by anatomical location, phenotype and function. In human, the two most accessible tissues to study leukocytes are peripheral blood and skin. DCs are rare in human peripheral blood (<1 % of mononuclear cells) and have a less mature phenotype than their tissue counterparts (MacDonald et al., Blood. 100:4512-4520, 2002; Haniffa et al., Immunity 37:60-73, 2012). In contrast, the skin covering an average total surface area of 1.8 m(2) has approximately tenfold more DCs than the average 5 L of total blood volume (Wang et al., J Invest Dermatol 134:965-974, 2014). DCs migrate spontaneously from skin explants cultured ex vivo, which provide an easy method of cell isolation (Larsen et al., J Exp Med 172:1483-1493, 1990; Lenz et al., J Clin Invest 92:2587-2596, 1993; Nestle et al., J Immunol 151:6535-6545, 1993). These factors led to the extensive use of skin DCs as the "prototype" migratory DCs in human studies. In this chapter, we detail the protocols to isolate DCs and resident macrophages from human skin. We also provide a multiparameter flow cytometry gating strategy to identify human skin DCs and to distinguish them from macrophages.

Adaptation of human skin color in various populations.

PubMed

Deng, Lian; Xu, Shuhua

2018-01-01

Skin color is a well-recognized adaptive trait and has been studied extensively in humans. Understanding the genetic basis of adaptation of skin color in various populations has many implications in human evolution and medicine. Impressive progress has been made recently to identify genes associated with skin color variation in a wide range of geographical and temporal populations. In this review, we discuss what is currently known about the genetics of skin color variation. We enumerated several cases of skin color adaptation in global modern humans and archaic hominins, and illustrated why, when, and how skin color adaptation occurred in different populations. Finally, we provided a summary of the candidate loci associated with pigmentation, which could be a valuable reference for further evolutionary and medical studies. Previous studies generally indicated a complex genetic mechanism underlying the skin color variation, expanding our understanding of the role of population demographic history and natural selection in shaping genetic and phenotypic diversity in humans. Future work is needed to dissect the genetic architecture of skin color adaptation in numerous ethnic minority groups around the world, which remains relatively obscure compared with that of major continental groups, and to unravel the exact genetic basis of skin color adaptation.

Non-ablative fractionated laser skin resurfacing for the treatment of aged neck skin.

PubMed

Bencini, Pier Luca; Tourlaki, Athanasia; Galimberti, Michela; Pellacani, Giovanni

2015-06-01

Aging of the neck skin includes poikiloderma of Civatte, skin laxity and wrinkles. While the vascular alterations of poikiloderma of Civatte can be effectively treated with lasers or intense pulsed light, a successful treatment of dyschromia, skin laxity and wrinkles is still difficult to achieve. To evaluate the safety and efficacy of non-ablative fractional 1540 erbium glass laser for the treatment of aged neck skin, also by means of in vivo reflectance confocal microscopy (RCM). A prospective study for neck resurfacing in 18 women with aged neck skin. Six laser treatments were performed in 4-week intervals with a 1540-nm erbium-glass fiber laser. By using a 6-point grading scale, the mean score (±SD; range) at baseline was 3.6 (±1.5; 1-6) for skin dyschromia, 2.9 (±1.4; 1-6) for laxity and 3.3 (±1.3; 1-5) for wrinkles. Three months after the last laser session, we found a significant clinical improvement of dyschromia (p = 0.0002; Wilcoxon test), and wrinkles (p = 0.0004; Wilcoxon test), with a mean (±SD) reduction of 2.5 (±1.0) and 1.9 (±1.1) points in the 6-point grading scale, respectively. No change was observed in laxity. These results were also supported by structural changes documented by RCM. Non-ablative fractional 1540 erbium glass laser was both safe and effective for the treatment of dyschromia and wrinkles, but not effective for the laxity of the neck skin.

Age-dependent increase in ortho-tyrosine and methionine sulfoxide in human skin collagen is not accelerated in diabetes. Evidence against a generalized increase in oxidative stress in diabetes.

PubMed Central

Wells-Knecht, M C; Lyons, T J; McCance, D R; Thorpe, S R; Baynes, J W

1997-01-01

The glycoxidation products Nepsilon-(carboxymethyl)lysine and pentosidine increase in skin collagen with age and at an accelerated rate in diabetes. Their age-adjusted concentrations in skin collagen are correlated with the severity of diabetic complications. To determine the relative roles of increased glycation and/or oxidation in the accelerated formation of glycoxidation products in diabetes, we measured levels of amino acid oxidation products, distinct from glycoxidative modifications of amino acids, as independent indicators of oxidative stress and damage to collagen in aging and diabetes. We show that ortho-tyrosine and methionine sulfoxide are formed in concert with Nepsilon-(carboxymethyl)lysine and pentosidine during glycoxidation of collagen in vitro, and that they also increase with age in human skin collagen. The age-adjusted levels of these oxidized amino acids in collagen was the same in diabetic and nondiabetic subjects, arguing that diabetes per se does not cause an increase in oxidative stress or damage to extracellular matrix proteins. These results provide evidence for an age-dependent increase in oxidative damage to collagen and support previous conclusions that the increase in glycoxidation products in skin collagen in diabetes can be explained by the increase in glycemia alone, without invoking a generalized, diabetes-dependent increase in oxidative stress. PMID:9259583

Three-Dimensional In Vitro Skin and Skin Cancer Models Based on Human Fibroblast-Derived Matrix.

PubMed

Berning, Manuel; Prätzel-Wunder, Silke; Bickenbach, Jackie R; Boukamp, Petra

2015-09-01

Three-dimensional in vitro skin and skin cancer models help to dissect epidermal-dermal and tumor-stroma interactions. In the model presented here, normal human dermal fibroblasts isolated from adult skin self-assembled into dermal equivalents with their specific fibroblast-derived matrix (fdmDE) over 4 weeks. The fdmDE represented a complex human extracellular matrix that was stabilized by its own heterogeneous collagen fiber meshwork, largely resembling a human dermal in vivo architecture. Complemented with normal human epidermal keratinocytes, the skin equivalent (fdmSE) thereof favored the establishment of a well-stratified and differentiated epidermis and importantly allowed epidermal regeneration in vitro for at least 24 weeks. Moreover, the fdmDE could be used to study the features of cutaneous skin cancer. Complementing fdmDE with HaCaT cells in different stages of malignancy or tumor-derived cutaneous squamous cell carcinoma cell lines, the resulting skin cancer equivalents (fdmSCEs) recapitulated the respective degree of tumorigenicity. In addition, the fdmSCE invasion phenotypes correlated with their individual degree of tissue organization, disturbance in basement membrane organization, and presence of matrix metalloproteinases. Together, fdmDE-based models are well suited for long-term regeneration of normal human epidermis and, as they recapitulate tumor-specific growth, differentiation, and invasion profiles of cutaneous skin cancer cells, also provide an excellent human in vitro skin cancer model.

Chromophores in human skin

NASA Astrophysics Data System (ADS)

Young, Antony R.

1997-05-01

Human skin, especially the epidermis, contains several major solar ultraviolet-radiation- (UVR-) absorbing endogenous chromophores including DNA, urocanic acid, amino acids, melanins and their precursors and metabolites. The lack of solubility of melanins prevents their absorption spectra being defined by routine techniques. Indirect spectroscopic methods show that their spectral properties depend on the stimulus for melanogenesis. The photochemical consequences of UVR absorption by some epidermal chromophores are relatively well understood whereas we lack a detailed understanding of the consequent photobiological and clinical responses. Skin action spectroscopy is not a reliable way of relating a photobiological outcome to a specific chromophore but is important for UVR hazard assessment. Exogenous chromophores may be administered to the skin in combination with UVR exposure for therapeutic benefit, or as sunscreens for the prevention of sunburn and possibly skin cancer.

The isolated perfused human skin flap model: A missing link in skin penetration studies?

PubMed

Ternullo, Selenia; de Weerd, Louis; Flaten, Gøril Eide; Holsæter, Ann Mari; Škalko-Basnet, Nataša

2017-01-01

Development of effective (trans)dermal drug delivery systems requires reliable skin models to evaluate skin drug penetration. The isolated perfused human skin flap remains metabolically active tissue for up to 6h during in vitro perfusion. We introduce the isolated perfused human skin flap as a close-to-in vivo skin penetration model. To validate the model's ability to evaluate skin drug penetration the solutions of a hydrophilic (calcein) and a lipophilic (rhodamine) fluorescence marker were applied. The skin flaps were perfused with modified Krebs-Henseleit buffer (pH7.4). Infrared technology was used to monitor perfusion and to select a well-perfused skin area for administration of the markers. Flap perfusion and physiological parameters were maintained constant during the 6h experiments and the amount of markers in the perfusate was determined. Calcein was detected in the perfusate, whereas rhodamine was not detectable. Confocal images of skin cross-sections shoved that calcein was uniformly distributed through the skin, whereas rhodamine accumulated in the stratum corneum. For comparison, the penetration of both markers was evaluated on ex vivo human skin, pig skin and cellophane membrane. The proposed perfused flap model enabled us to distinguish between the penetrations of the two markers and could be a promising close-to-in vivo tool in skin penetration studies and optimization of formulations destined for skin administration. Copyright © 2016 Elsevier B.V. All rights reserved.

Bifidobacterium-fermented soy milk extract stimulates hyaluronic acid production in human skin cells and hairless mouse skin.

PubMed

Miyazaki, K; Hanamizu, T; Iizuka, R; Chiba, K

2003-01-01

We examined the effects of Bifidobasterium-fermented (BE) and nonfermented (SME) soy milk extracts on the production of hyaluronic acid (HA) in vitro and in vivo. BE, but not SME, significantly enhanced the production of HA in monolayer and organotypic cultures of human keratinocytes, in cultures of human skin fibroblasts, and in hairless mouse skin following topical application for 2 weeks. In the organotypic cultures formed by a similar structure to human epidermis, BE also extended the distribution of HA. Genistein and daidzein, known to stimulate HA production, were detected in BE at a concentration of 0.18 and 0.07 mM, respectively, but not in SME. Therefore, BE has the potential to enhance HA production in the epidermis and dermis, mainly due to genistein released from its glycoside during fermentation. BE is expected to prevent the age-dependent loss of cutaneous HA. Copyright 2003 S. Karger AG, Basel

Cold-induced vasoconstriction at forearm and hand skin sites: the effect of age

PubMed Central

Frijns, A. J. H.; Saris, W. H. M.; van Steenhoven, A. A.; van Marken Lichtenbelt, W. D.

2010-01-01

During mild cold exposure, elderly are at risk of hypothermia. In humans, glabrous skin at the hands is well adapted as a heat exchanger. Evidence exists that elderly show equal vasoconstriction due to local cooling at the ventral forearm, yet no age effects on vasoconstriction at hand skin have been studied. Here, we tested the hypotheses that at hand sites (a) elderly show equal vasoconstriction due to local cooling and (b) elderly show reduced response to noradrenergic stimuli. Skin perfusion and mean arterial pressure were measured in 16 young adults (Y: 18–28 years) and 16 elderly (E: 68–78 years). To study the effect of local vasoconstriction mechanisms local sympathetic nerve terminals were blocked by bretylium (BR). Baseline local skin temperature was clamped at 33°C. Next, local temperature was reduced to 24°C. After 15 min of local cooling, noradrenalin (NA) was administered to study the effect of neural vasoconstriction mechanisms. No significant age effect was observed in vasoconstriction due to local cooling at BR sites. After NA, vasoconstriction at the forearm showed a significant age effect; however, no significant age effect was found at the hand sites. [Change in CVC (% from baseline): Forearm Y: −76 ± 3 vs. E: −60 ± 5 (P < 0.01), dorsal hand Y: −74 ± 4 vs. E: −72 ± 4 (n.s.), ventral hand Y: −80 ± 7 vs. E: −70 ± 11 (n.s.)]. In conclusion, in contrast to results from the ventral forearm, elderly did not show a blunted response to local cooling and noradrenalin at hand skin sites. This indicates that at hand skin the noradrenergic mechanism of vasoconstriction is maintained with age. PMID:20300768

Development of skin aging scale by using dermoscopy.

PubMed

Isik, Burcu; Gurel, Mehmet S; Erdemir, Asli T; Kesmezacar, Ozgu

2013-05-01

Some features of skin aging that cannot be detected by the naked eye can be determined more easily by dermoscopy. Therefore, we aimed to measure skin aging with dermoscopy. The study was performed in Istanbul Training and Research Hospital, a tertiary care referral center. A total of 441 participants between the ages of 20-88 (mean 48.4 ± 17.7) were separated into six groups according to their age. All participant's facial sun-exposed areas were examined by dermoscopy in terms of telangiectasia, vascular changes, pigmentation changes, seborrheic keratosis, actinic keratosis, periorbital comedones and cysts, superficial- deep- criss-cross wrinkles as the signs of photoaging and scored with the help of dermoscopic photoaging scale (DPAS). The validity of the scale was assessed with DPAS by the evaluation of both the axillar and the gluteal regions, that were not sun exposed and photoaged, with DPAS. The scale was found to be highly reliable as Cronbach's α coefficient was 0.756. Skin aging of patients from every decade was compared clinically with Glogou photoaging scale and Monheit-Fulton photoaging index and significant correlation was calculated as 0.773 and 0.774, respectively. An increase in photoaging scores from young people toward elders according to their ages was observed and the same linear difference between their mean values was detected. DPAS is a reliable and valid diagnostic tool that can evaluate photoaged skin quantitatively by the help of objective criteria so can be used to evaluate the effect of preventive and therapeutic applications for skin aging. © 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

The relationship between skin aging and steady state ultraweak photon emission as an indicator of skin oxidative stress in vivo.

PubMed

Gabe, Y; Osanai, O; Takema, Y

2014-08-01

Ultraweak photon emission (UPE) is one potential method to evaluate the oxidative status of the skin in vivo. However, little is known about how the daily oxidative stress of the skin is related to skin aging-related alterations in vivo. We characterized the steady state UPE and performed a skin survey. We evaluated the skin oxidative status by UPE, skin elasticity, epidermal thickness and skin color on the inner upper arm, the outer forearm, and the buttock of 70 Japanese volunteers. The steady state UPE at the three skin sites increased with age. Correlation analysis revealed that the steady state UPE only from the buttock was related to skin elasticity, which showed age-dependent changes. Moreover, analysis by age group indicated that b* values of the inner upper arm of subjects in their 20s were inversely correlated with UPE as occurred in buttock skin. In contrast, photoaged skin did not show a clear relationship with steady state UPE because the accumulation of sun-exposure might influence the sensitivity to oxidative stress. These results suggest that steady state UPE reflects not only intrinsic skin aging and cutaneous color but also the current oxidative status independent of skin aging. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Meta-Profiles of Gene Expression during Aging: Limited Similarities between Mouse and Human and an Unexpectedly Decreased Inflammatory Signature

PubMed Central

Swindell, William R.; Johnston, Andrew; Sun, Liou; Xing, Xianying; Fisher, Gary J.; Bulyk, Martha L.; Elder, James T.; Gudjonsson, Johann E.

2012-01-01

Background Skin aging is associated with intrinsic processes that compromise the structure of the extracellular matrix while promoting loss of functional and regenerative capacity. These processes are accompanied by a large-scale shift in gene expression, but underlying mechanisms are not understood and conservation of these mechanisms between humans and mice is uncertain. Results We used genome-wide expression profiling to investigate the aging skin transcriptome. In humans, age-related shifts in gene expression were sex-specific. In females, aging increased expression of transcripts associated with T-cells, B-cells and dendritic cells, and decreased expression of genes in regions with elevated Zeb1, AP-2 and YY1 motif density. In males, however, these effects were contrasting or absent. When age-associated gene expression patterns in human skin were compared to those in tail skin from CB6F1 mice, overall human-mouse correspondence was weak. Moreover, inflammatory gene expression patterns were not induced with aging of mouse tail skin, and well-known aging biomarkers were in fact decreased (e.g., Clec7a, Lyz1 and Lyz2). These unexpected patterns and weak human-mouse correspondence may be due to decreased abundance of antigen presenting cells in mouse tail skin with age. Conclusions Aging is generally associated with a pro-inflammatory state, but we have identified an exception to this pattern with aging of CB6F1 mouse tail skin. Aging therefore does not uniformly heighten inflammatory status across all mouse tissues. Furthermore, we identified both intercellular and intracellular mechanisms of transcriptome aging, including those that are sex- and species-specific. PMID:22413003

Survey on skin aging status and related influential factors in Southeast China.

PubMed

Wang, Yi-na; Fang, Hong; Zhu, Wei-fang

2009-01-01

To investigate cutaneous aging patterns of residents in Hangzhou, Zhejiang, China, and their contributing factors. Eight hundred and forty-eight Hangzhou residents received the survey between March 2004 and September 2004. Facial wrinkling first occurred at 21 years of age and skin elasticity began to lose at 22 years of age. In middle-aged and old people, facial wrinkling and looseness escalated with the increase of ultraviolet (UV)-exposure time, indicating the accelerating effect of a higher accumulative dose of UV radiation on skin aging. Only Fitzpatrick types II, III and IV were found in the skin phototypes of residents in Hangzhou area, and Fitzpatrick type II seemed to be much more subject to severe wrinkling, elasticity destruction and skin tumors than types III and IV. The oily skin was more protected against wrinkling and facial looseness than dry skin. However, as to concomitant cutaneous diseases, no difference was found among different skin types. Age, solar-exposure time, Fitzpatrick type and skin type are the associated forces in promoting skin aging, and emotional factor seems to be another independent risk factor. The age of 49 years and 2 h/d of solar-exposure time seem to be the turning points responsible for dramatic changes of cutaneous appearance in the process of skin aging in Southeast China.

Advanced haptic sensor for measuring human skin conditions

NASA Astrophysics Data System (ADS)

Tsuchimi, Daisuke; Okuyama, Takeshi; Tanaka, Mami

2009-12-01

This paper is concerned with the development of a tactile sensor using PVDF (Polyvinylidene Fluoride) film as a sensory receptor of the sensor to evaluate softness, smoothness, and stickiness of human skin. Tactile sense is the most important sense in the sensation receptor of the human body along with eyesight, and we can examine skin condition quickly using these sense. But, its subjectivity and ambiguity make it difficult to quantify skin conditions. Therefore, development of measurement device which can evaluate skin conditions easily and objectively is demanded by dermatologists, cosmetic industries, and so on. In this paper, an advanced haptic sensor system that can measure multiple information of skin condition in various parts of human body is developed. The applications of the sensor system to evaluate softness, smoothness, and stickiness of skin are investigated through two experiments.

Advanced haptic sensor for measuring human skin conditions

NASA Astrophysics Data System (ADS)

Tsuchimi, Daisuke; Okuyama, Takeshi; Tanaka, Mami

2010-01-01

This paper is concerned with the development of a tactile sensor using PVDF (Polyvinylidene Fluoride) film as a sensory receptor of the sensor to evaluate softness, smoothness, and stickiness of human skin. Tactile sense is the most important sense in the sensation receptor of the human body along with eyesight, and we can examine skin condition quickly using these sense. But, its subjectivity and ambiguity make it difficult to quantify skin conditions. Therefore, development of measurement device which can evaluate skin conditions easily and objectively is demanded by dermatologists, cosmetic industries, and so on. In this paper, an advanced haptic sensor system that can measure multiple information of skin condition in various parts of human body is developed. The applications of the sensor system to evaluate softness, smoothness, and stickiness of skin are investigated through two experiments.

Improvement in skin wrinkles using a preparation containing human growth factors and hyaluronic acid serum.

PubMed

Lee, Do Hyun; Oh, In Young; Koo, Kyo Tan; Suk, Jang Mi; Jung, Sang Wook; Park, Jin Oh; Kim, Beom Joon; Choi, Yoo Mi

2015-02-01

Skin aging is accompanied by wrinkle formation. At some sites, such as the periorbital skin, this is a relatively early phenomenon. We evaluated the anti-wrinkle effect of a preparation containing human growth factor and hyaluronic acid serum on periorbital wrinkles (crow's feet). In total, 23 Korean women (age range: 39-59 years), who were not pregnant, nursing, or undergoing any concurrent therapy, were enrolled in this study. All the patients completed an 8-week trial of twice-daily application of human growth factor and hyaluronic acid serum on the entire face. Efficacy was based on a global photodamage score, photographs, and image analysis using replicas and visiometer analysis every 4 weeks. The standard wrinkle and roughness parameters used in assessing skin by visiometer were calculated and statistically analyzed. Periorbital wrinkles were significantly improved after treatment, with improvements noted both by physician's assessment and visiometer analysis. Topical application of human growth factor and hyaluronic acid was beneficial in reducing periorbital wrinkles.

Materials used to simulate physical properties of human skin.

PubMed

Dąbrowska, A K; Rotaru, G-M; Derler, S; Spano, F; Camenzind, M; Annaheim, S; Stämpfli, R; Schmid, M; Rossi, R M

2016-02-01

For many applications in research, material development and testing, physical skin models are preferable to the use of human skin, because more reliable and reproducible results can be obtained. This article gives an overview of materials applied to model physical properties of human skin to encourage multidisciplinary approaches for more realistic testing and improved understanding of skin-material interactions. The literature databases Web of Science, PubMed and Google Scholar were searched using the terms 'skin model', 'skin phantom', 'skin equivalent', 'synthetic skin', 'skin substitute', 'artificial skin', 'skin replica', and 'skin model substrate.' Articles addressing material developments or measurements that include the replication of skin properties or behaviour were analysed. It was found that the most common materials used to simulate skin are liquid suspensions, gelatinous substances, elastomers, epoxy resins, metals and textiles. Nano- and micro-fillers can be incorporated in the skin models to tune their physical properties. While numerous physical skin models have been reported, most developments are research field-specific and based on trial-and-error methods. As the complexity of advanced measurement techniques increases, new interdisciplinary approaches are needed in future to achieve refined models which realistically simulate multiple properties of human skin. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Jasmine rice panicle: A safe and efficient natural ingredient for skin aging treatments.

PubMed

Kanlayavattanakul, Mayuree; Lourith, Nattaya; Chaikul, Puxvadee

2016-12-04

While rice is one of the most important global staple food sources its extracts have found many uses as the bases of herbal remedies. Rice extracts contain high levels of phenolic compounds which are known to be bioactive, some of which show cutaneous benefits and activity towards skin disorders. This study highlights an assessment of the cellular activity and clinical efficacy of rice panicle extract, providing necessary information relevant to the development of new cosmetic products. Jasmine rice panicle extract was standardized, and the level of phenolics present was determined. In vitro anti-aging, and extract activity towards melanogenesis was conducted in B16F10 melanoma cells, and antioxidant activity was assessed in human skin fibroblast cell cultures. Topical product creams containing the extract were developed, and skin irritation testing using a single application closed patch test method was done using 20 Thai volunteers. Randomized double-blind, placebo-controlled efficacy evaluation was undertaken in 24 volunteers over an 84d period, with the results monitored by Corneometer ® CM 825, Cutometer ® MPA 580, Mexameter ® MX 18 and Visioscan ® VC 98. Jasmine rice panicle extract was shown to have a high content of p-coumaric, ferulic and caffeic acids, and was not cytotoxic to the cell lines used in this study. Cells treated with extract suppressed melanogenesis via tyrosinase and TRP-2 inhibitory effects, which protect the cell from oxidative stress at doses of 0.1mg/ml or lower. The jasmine rice panicle preparations (0.1-0.2%) were safe (MII=0), and significantly (p<0.05) increased skin hydration levels relative to baseline. Skin lightening, and anti-wrinkle effects related to skin firmness and smoothness were observed, in addition to a reduction in skin wrinkling. Improvements in skin biophysics of both 0.1% and 0.2% extracts were showed to be comparable (p>0.05). Jasmine rice panicle extract having high levels of phenolics shows cutaneous benefits

Evaluation of dermal-epidermal skin equivalents ('composite-skin') of human keratinocytes in a collagen-glycosaminoglycan matrix(Integra artificial skin).

PubMed

Kremer, M; Lang, E; Berger, A C

2000-09-01

Integra artificial skin (Integra LifeSciences Corp., Plainsboro, NJ, USA) is a dermal template consisting of bovine collagen, chondroitin-6-sulphate and a silastic membrane manufactured as Integra. This product has gained widespread use in the clinical treatment of third degree burn wounds and full thickness skin defects of different aetiologies. The product was designed to significantly reduce the time needed to achieve final wound closure in the treatment of major burn wounds, to optimise the sparse autologous donor skin resources and to improve the durable mechanical quality of the skin substitute. The clinical procedure requires two stages. The first step creates a self neodermis, the second creates a self epidermis on the neodermis. However, it is desirable to cover major burn wounds early in a single step by a skin substitute consisting of a dermal equivalent seeded in vitro with autologous keratinocytes ('composite-skin') out of which a full thickness skin develops in vivo.The goal of this experimental study was to develop a method to integrate human keratinocytes in homogeneous distribution and depth into Integra Artificial Skin. The seeded cell-matrix composites were grafted onto athymic mice in order to evaluate their potential to reconstitute a human epidermis in vivo. We were able to demonstrate that the inoculated human keratinocytes reproducibly displayed a homogeneous pattern of distribution, adherence, proliferation and confluence. The cell-matrix composites grafted in this model exhibited good wound adherence, complete healing, minor wound contraction and had the potential to reconstitute an elastic, functional and durable human skin. Histologically we were able to show that the inoculated human keratinocytes in vivo colonised the matrix in a histomorphologically characteristic epidermal pattern (keratomorula, keratinocyte bubbling) and developed a persisting, stratified, keratinising epidermis which immunohistologically proved to be of human

Cloud-based Monte Carlo modelling of BSSRDF for the rendering of human skin appearance (Conference Presentation)

NASA Astrophysics Data System (ADS)

Doronin, Alexander; Rushmeier, Holly E.; Meglinski, Igor; Bykov, Alexander V.

2016-03-01

We present a new Monte Carlo based approach for the modelling of Bidirectional Scattering-Surface Reflectance Distribution Function (BSSRDF) for accurate rendering of human skin appearance. The variations of both skin tissues structure and the major chromophores are taken into account correspondingly to the different ethnic and age groups. The computational solution utilizes HTML5, accelerated by the graphics processing units (GPUs), and therefore is convenient for the practical use at the most of modern computer-based devices and operating systems. The results of imitation of human skin reflectance spectra, corresponding skin colours and examples of 3D faces rendering are presented and compared with the results of phantom studies.

Chemical ecology of interactions between human skin microbiota and mosquitoes.

PubMed

Verhulst, Niels O; Takken, Willem; Dicke, Marcel; Schraa, Gosse; Smallegange, Renate C

2010-10-01

Microbiota on the human skin plays a major role in body odour production. The human microbial and chemical signature displays a qualitative and quantitative correlation. Genes may influence the chemical signature by shaping the composition of the microbiota. Recent studies on human skin microbiota, using 16S rRNA gene sequencing, found a high inter- and intrapersonal variation in bacterial species on the human skin, which is relatively stable over time. Human body odours mediate the attraction of mosquitoes to their blood hosts. Odours produced by skin microbiota are attractive to mosquitoes as shown by in vitro studies, and variation in bacterial species on the human skin may explain the variation in mosquito attraction between humans. Detailed knowledge of the ecology and genetics of human skin microbiota is needed in order to unravel the evolutionary mechanisms that underlie the interactions between mosquitoes and their hosts. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Human skin wetness perception: psychophysical and neurophysiological bases.

PubMed

Filingeri, Davide; Havenith, George

2015-01-01

The ability to perceive thermal changes in the surrounding environment is critical for survival. However, sensing temperature is not the only factor among the cutaneous sensations to contribute to thermoregulatory responses in humans. Sensing skin wetness (i.e. hygrosensation) is also critical both for behavioral and autonomic adaptations. Although much has been done to define the biophysical role of skin wetness in contributing to thermal homeostasis, little is known on the neurophysiological mechanisms underpinning the ability to sense skin wetness. Humans are not provided with skin humidity receptors (i.e., hygroreceptors) and psychophysical studies have identified potential sensory cues (i.e. thermal and mechanosensory) which could contribute to sensing wetness. Recently, a neurophysiological model of human wetness sensitivity has been developed. In helping clarifying the peripheral and central neural mechanisms involved in sensing skin wetness, this model has provided evidence for the existence of a specific human hygrosensation strategy, which is underpinned by perceptual learning via sensory experience. Remarkably, this strategy seems to be shared by other hygroreceptor-lacking animals. However, questions remain on whether these sensory mechanisms are underpinned by specific neuromolecular pathways in humans. Although the first study on human wetness perception dates back to more than 100 years, it is surprising that the neurophysiological bases of such an important sensory feature have only recently started to be unveiled. Hence, to provide an overview of the current knowledge on human hygrosensation, along with potential directions for future research, this review will examine the psychophysical and neurophysiological bases of human skin wetness perception.

Human skin wetness perception: psychophysical and neurophysiological bases

PubMed Central

Filingeri, Davide; Havenith, George

2015-01-01

The ability to perceive thermal changes in the surrounding environment is critical for survival. However, sensing temperature is not the only factor among the cutaneous sensations to contribute to thermoregulatory responses in humans. Sensing skin wetness (i.e. hygrosensation) is also critical both for behavioral and autonomic adaptations. Although much has been done to define the biophysical role of skin wetness in contributing to thermal homeostasis, little is known on the neurophysiological mechanisms underpinning the ability to sense skin wetness. Humans are not provided with skin humidity receptors (i.e., hygroreceptors) and psychophysical studies have identified potential sensory cues (i.e. thermal and mechanosensory) which could contribute to sensing wetness. Recently, a neurophysiological model of human wetness sensitivity has been developed. In helping clarifying the peripheral and central neural mechanisms involved in sensing skin wetness, this model has provided evidence for the existence of a specific human hygrosensation strategy, which is underpinned by perceptual learning via sensory experience. Remarkably, this strategy seems to be shared by other hygroreceptor-lacking animals. However, questions remain on whether these sensory mechanisms are underpinned by specific neuromolecular pathways in humans. Although the first study on human wetness perception dates back to more than 100 years, it is surprising that the neurophysiological bases of such an important sensory feature have only recently started to be unveiled. Hence, to provide an overview of the current knowledge on human hygrosensation, along with potential directions for future research, this review will examine the psychophysical and neurophysiological bases of human skin wetness perception. PMID:27227008

Xenobiotica-metabolizing enzymes in the skin of rat, mouse, pig, guinea pig, man, and in human skin models.

PubMed

Oesch, F; Fabian, E; Landsiedel, Robert

2018-06-18

Studies on the metabolic fate of medical drugs, skin care products, cosmetics and other chemicals intentionally or accidently applied to the human skin have become increasingly important in order to ascertain pharmacological effectiveness and to avoid toxicities. The use of freshly excised human skin for experimental investigations meets with ethical and practical limitations. Hence information on xenobiotic-metabolizing enzymes (XME) in the experimental systems available for pertinent studies compared with native human skin has become crucial. This review collects available information of which-taken with great caution because of the still very limited data-the most salient points are: in the skin of all animal species and skin-derived in vitro systems considered in this review cytochrome P450 (CYP)-dependent monooxygenase activities (largely responsible for initiating xenobiotica metabolism in the organ which provides most of the xenobiotica metabolism of the mammalian organism, the liver) are very low to undetectable. Quite likely other oxidative enzymes [e.g. flavin monooxygenase, COX (cooxidation by prostaglandin synthase)] will turn out to be much more important for the oxidative xenobiotic metabolism in the skin. Moreover, conjugating enzyme activities such as glutathione transferases and glucuronosyltransferases are much higher than the oxidative CYP activities. Since these conjugating enzymes are predominantly detoxifying, the skin appears to be predominantly protected against CYP-generated reactive metabolites. The following recommendations for the use of experimental animal species or human skin in vitro models may tentatively be derived from the information available to date: for dermal absorption and for skin irritation esterase activity is of special importance which in pig skin, some human cell lines and reconstructed skin models appears reasonably close to native human skin. With respect to genotoxicity and sensitization reactive

Rejuvenation of aged pig facial skin by transplanting allogeneic granulocyte colony-stimulating factor-induced peripheral blood stem cells from a young pig.

PubMed

Harn, Horng-Jyh; Huang, Mao-Hsuan; Huang, Chi-Ting; Lin, Po-Cheng; Yen, Ssu-Yin; Chou, Yi-Wen; Ho, Tsung-Jung; Chu, Hen-Yi; Chiou, Tzyy-Wen; Lin, Shinn-Zong

2013-01-01

Following a stroke, the administration of stem cells that have been treated with granulocyte colony-stimulating factor (GCSF) can ameliorate functional deficits in both rats and humans. It is not known, however, whether the application of GCSF-mobilized peripheral blood stem cells (PBSCs) to human skin can function as an antiaging treatment. We used a Lanyu pig (Sus scrofa) model, since compared with rodents, the structure of a pig's skin is very similar to human skin, to provide preliminary data on whether these cells can exert antiaging effects over a short time frame. GCSF-mobilized PBSCs from a young male Lanyu pig (5 months) were injected intradermally into the cheek skin of aged female Lanyu pigs, and tissues before and after the cell injections were compared to determine whether this treatment caused skin rejuvenation. Increased levels of collagen, elastin, hyaluronic acid, and the hyaluronic acid receptor CD44 were observed in both dermal and subcutaneous layers following the injection of PBSCs. In addition, the treated skin tissue was tighter and more elastic than adjacent control regions of aged skin tissue. In the epidermal layer, PBSC injection altered the levels of both involucrin and integrin, indicating an increased rate of epidermal cell renewal as evidenced by reductions in both cornified cells and cells of the spinous layers and increases in the number of dividing cells within the basal layer. We found that the exogenous PBSCs, visualized using fluorescence in situ hybridization, were located primarily in hair follicles and adjacent tissues. In summary, PBSC injection restored young skin properties in the skin of aged (90 months) pigs. On the basis of our preliminary data, we conclude that intradermal injection of GCSF-mobilized PBSCs from a young pig can rejuvenate the skin in aged pigs.

Optical coherence tomography applied to tests of skin care products in humans--a case study.

PubMed

Vasquez-Pinto, L M C; Maldonado, E P; Raele, M P; Amaral, M M; de Freitas, A Z

2015-02-01

When evaluating skin care products for human skin, quantitative test methods need to be simple, precise and reliable. Optical coherence tomography (OCT), provides high-resolution sectional images of translucent materials to a depth of a few millimeters, a technique usually applied to medical measurements in ophthalmology and dermatology. This study aimed to demonstrate the application of OCT as the main technique for monitoring changes in skin topography during tests of a wrinkle-reduction product in humans. We used a commercial OCT apparatus to perform clinical examinations of skin roughness in treated and non-treated sites in the periorbital region of thirty human voluntaries who were using an anti-aging product commercially available: Natura Chronos® Flavonóides de Passiflora 45+ FPS15, from Natura Cosméticos, Brazil. Measurements were performed days 0, 7, 14 and 28 of treatment. Equipment and software allowed real-time recording of skin roughness parameters and wrinkle depths. The OCT measurements have allowed the monitoring of changes in skin roughness, which have shown reduction in treated sites around 10%. The obtained depth distributions also indicate reduction in the occurrence of wrinkles deeper than 170 μm. The verified results are consistent with those typically obtained after successful treatment with modern anti-aging products. By using the OCT technique, it was possible to quantify changes in skin roughness and in the distribution of depths of skin wrinkles, with adequate sensitivity. OCT imaging allows the direct visualization of the skin topography with resolution of micrometers, a reliable and interactive tool for clinical use. Therefore, for the first time, we demonstrated the use of OCT technique to verify the efficacy of cosmetic products in real time. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Comparison of two methods for noninvasive determination of carotenoids in human and animal skin: Raman spectroscopy versus reflection spectroscopy.

PubMed

Darvin, Maxim E; Sandhagen, Carl; Koecher, Wolfgang; Sterry, Wolfram; Lademann, Juergen; Meinke, Martina C

2012-07-01

Based on compelling in vivo and in vitro studies on human skin, carotenoids are thought to be of great interest as powerful antioxidants acting to prevent free-radical-induced damages, including premature skin ageing and the development of skin diseases such as cancer. Among the available techniques that are suitable for noninvasive determination of carotenoids in human skin, are resonance Raman spectroscopy (RRS) and reflection spectroscopy (RS). For RS, a LED-based miniaturized spectroscopic system (MSS) was developed for noninvasive measurement of carotenoids in human skin. The optimization and subsequent calibration of the MSS was performed with the use of RRS. A strong correlation between the carotenoid concentration determined by the RS and for the RRS system was achieved for human skin in vivo (R = 0.88) and for bovine udder skin in vitro (R = 0.81). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Wave propagation as a marker of structural and topographic properties of human skin

NASA Astrophysics Data System (ADS)

Djaghloul, M.; Abdouni, A.; Thieulin, C.; Zahouani, H.

2018-06-01

Chronological skin ageing is a phenomenon which imposes structural and functional changes on the cutaneous tissue. Mechanically, these changes can be related to structural rearrangements of the cutaneous tissue on surface and in volume (layers thickness). At the micro-structural level, the constitutional elements of the skin, collagen and elastin fibres, undergo also this rearrangement. The evolution of skin’s mechanical properties at this level is the origin of a primordial in-vivo mechanical characteristic known as the natural pretension. In the context of understanding the in-vivo skin mechanical behaviour, related to the natural pretension, a lot of instrumentations have been demonstrated in the literature. They are mainly based on the interaction between dynamic adapted solicitation and the observed reaction on the skin. In this study, we evaluate the mechanical behaviour of human skin, following an impact which induces wave propagation. The use of impact solicitation allows the direct correlation between the dynamic induced reaction (vibration, and wave propagation) of the cutaneous tissue and its mechanical property. In our development, impact solicitation is contactless, with an air blast as generator of local deformation. The estimation of the speed of wave propagation enables the characterization of the mechanical behaviour of the skin. In order to validate the developed approaches, to understand the chronological ageing, gender and anisotropy effects on the skin properties, measurements have been realized on 77 healthy volunteers separated in five age groups. The obtained results are consistent with earlier works and confirm the efficiency of the developed instrumentation to estimate the changes of mechanical behaviour of the skin under age and gender effects.

Anti-Aging Effects of the Hanwoo Leg Bone, Foot and Tail Infusions (HLI, HFI and HTI) on Skin Fibroblast.

PubMed

Seol, Ja Young; Yoon, Ji Young; Jeong, Hee Sun; Joo, Nami; Choi, Soon Young

2016-01-01

Many researchers revealed that collagen contribute to maintaining the skin's elasticity and inhibit wrinkling of skin. Korean native cattle (Hanwoo) bone (leg bone, foot and tail) infusion contains the various inorganic materials, collagen and chondroitin sulfate. All of this, a large quantity of collagen is included in Hanwoo infusion. Therefore, this study emphasized on the effects of collagen in the Hanwoo bone infusion. For the first time, Hanwoo bone infusions were directly added to the media of Human Dermal Fibroblast (NHDF-c) to test anti-aging effects. First, it was identified that growth rate of skin fibroblast was increased. Furthermore, the Hanwoo bone infusion increased a 50% of fibroblast collagen synthesis. Also, suppression of skin fibroblast aging was confirmed by treatment Hanwoo bone infusion. In conclusion, this study demonstrates the effects of infusion made from Hanwoo leg bone, foot and tail on anti-aging, wrinkle inhibiting and skin fibroblast elasticity maintaining. Therefore, this study identified that traditional infusion has effects that are good for skin elasticity.

Age-related changes in cyclic phosphatidic acid-induced hyaluronic acid synthesis in human fibroblasts.

PubMed

Sano, Katsura; Gotoh, Mari; Dodo, Kyoko; Tajima, Noriaki; Shimizu, Yoshibumi; Murakami-Murofushi, Kimiko

2018-01-01

Hyaluronic acid is a major component of the extracellular matrix, which is important for skin hydration. As aging brings skin dehydration, we aimed to clarify the mRNA expression of hyaluronic acid-related proteins in human skin fibroblasts from donors of various ages (range 0.7-69 years). Previously, we reported that cyclic phosphatidic acid (cPA), a unique phospholipid mediator, stimulated the expression of HAS2 and increased hyaluronic acid synthesis in human skin fibroblasts (donor age: 3 days). In this study, we measured the mRNA expression of hyaluronic acid-related proteins: hyaluronan synthase (HAS) 1-3, hyaluronidase-1, -2, and hyaluronic acid-binding protein (versican). In addition, we tested whether cPA could increase hyaluronic acid synthesis in skin fibroblasts derived from donors of various ages. The expression of HAS1, 3, hyaluronidase-1, and -2 did not change with aging. However, the mRNA expression of versican decreased with aging. Although it is thought that the amount of hyaluronic acid in the dermis decreases with aging, the mRNA expression of HAS2 was increased. But the amount of hyaluronic acid secreted by fibroblasts did not increase with aging. This suggests that the activity and/or protein expression of HAS2 decrease with aging. Furthermore, we observed that cPA caused the increase of hyaluronic acid synthesis at any age, and this effect was increased with aging. These results suggest that aging made the fibroblasts more sensitive to cPA treatment. Therefore, cPA represents a suitable candidate for the health maintenance and improvement of the skin by increasing the level of hyaluronic acid in the dermis.

Quantitative characterization of mechanically indented in vivo human skin in adults and infants using optical coherence tomography

NASA Astrophysics Data System (ADS)

Huang, Pin-Chieh; Pande, Paritosh; Shelton, Ryan L.; Joa, Frank; Moore, Dave; Gillman, Elisa; Kidd, Kimberly; Nolan, Ryan M.; Odio, Mauricio; Carr, Andrew; Boppart, Stephen A.

2017-03-01

Influenced by both the intrinsic viscoelasticity of the tissue constituents and the time-evolved redistribution of fluid within the tissue, the biomechanical response of skin can reflect not only localized pathology but also systemic physiology of an individual. While clinical diagnosis of skin pathologies typically relies on visual inspection and manual palpation, a more objective and quantitative approach for tissue characterization is highly desirable. Optical coherence tomography (OCT) is an interferometry-based imaging modality that enables in vivo assessment of cross-sectional tissue morphology with micron-scale resolution, which surpasses those of most standard clinical imaging tools, such as ultrasound imaging and magnetic resonance imaging. This pilot study investigates the feasibility of characterizing the biomechanical response of in vivo human skin using OCT. OCT-based quantitative metrics were developed and demonstrated on the human subject data, where a significant difference between deformed and nondeformed skin was revealed. Additionally, the quantified postindentation recovery results revealed differences between aged (adult) and young (infant) skin. These suggest that OCT has the potential to quantitatively assess the mechanically perturbed skin as well as distinguish different physiological conditions of the skin, such as changes with age or disease.

Relationship between arsenic skin lesions and the age of natural menopause.

PubMed

Yunus, Fakir Md; Rahman, Musarrat Jabeen; Alam, Md Zahidul; Hore, Samar Kumar; Rahman, Mahfuzar

2014-05-02

Chronic exposure to arsenic is associated with neoplastic, cardiovascular, endocrine, neuro-developmental disorders and can have an adverse effect on women's reproductive health outcomes. This study examined the relationship between arsenic skin lesions (a hallmark sign of chronic arsenic poisoning) and age of natural menopause (final menopausal period) in populations with high levels of arsenic exposure in Bangladesh. We compared menopausal age in two groups of women--with and without arsenic skin lesions; and presence of arsenic skin lesions was used as an indicator for chronic arsenic exposure. In a cross-sectional study, a total of 210 participants were randomly identified from two ongoing studies--participants with arsenic skin lesions were identified from an ongoing clinical trial and participants with no arsenic skin lesions were identified from an ongoing cohort study. Mean age of menopause between these two groups were calculated and compared. Multivariable linear regression was used to estimate the relationship between the status of the arsenic skin lesions and age of natural menopause in women. Women with arsenic skin lesions were 1.5 years younger (p <0.001) at the time of menopause compared to those without arsenic skin lesions. After adjusting with contraceptive use, body mass index, urinary arsenic level and family history of premature menopause, the difference between the groups' age at menopause was 2.1 years earlier (p <0.001) for respondents with arsenic skin lesions. The study showed a statistically significant association between chronic exposure to arsenic and age at menopause. Heavily exposed women experienced menopause two years earlier than those with lower or no exposure.

Biohydrogels for the In Vitro Re-construction and In Situ Regeneration of Human Skin

NASA Astrophysics Data System (ADS)

Korkina, Liudmila; Kostyuk, Vladimir; Guerra, Liliana

Natural and synthetic biohydrogels are of great interest for the development of innovative medicinal and cosmetic products feasible for the treatment of numerous skin diseases and age-related changes in skin structure and function. Here, the characteristics of bio-resorbable hydrogels as scaffolds for the in vitro re-construction of temporary skin substitutes or full skin equivalents for further transplantation are reviewed. Another fast developing area of regenerative medicine is the in situ regeneration of human skin. The approach is mainly applicable to activate and facilitate the skin regeneration process and angiogenesis in chronic wounds with impaired healing. In this case, extracellular matrix resembling polymers are used to stimulate cell growth, adhesion, and movement. Better results could be achieved by activation of biocompatible hydrogels either with proteins (growth factors, adhesion molecules or/and cytokines) or with allogenic skin cells producing and releasing these molecules. Hydrogels are widely applied as carriers of low molecular weight substances with antioxidant, anti-inflammatory, anti-ageing, and wound healing action. Incorporation of these substances into hydrogels enhances their penetration through the skin barrier and prevents their destruction by oxidation. Potential roles of hydrogel-based products for modern dermatology and cosmetology are also discussed.

Polycomponent mesotherapy formulations for the treatment of skin aging and improvement of skin quality

PubMed Central

Prikhnenko, Sergey

2015-01-01

Skin aging can largely be attributed to dermal fibroblast dysfunction and a decrease in their biosynthetic activity. Regardless of the underlying causes, aging fibroblasts begin to produce elements of the extracellular matrix in amounts that are insufficient to maintain the youthful appearance of skin. The goal of mesopreparations is primarily to slow down and correct changes in skin due to aging. The rationale for developing complex polycomponent mesopreparations is based on the principle that aging skin needs to be supplied with the various substrates that are key to the adequate functioning of the fibroblast. The quintessential example of a polycomponent formulation – NCTF® (New Cellular Treatment Factor) – includes vitamins, minerals, amino acids, nucleotides, coenzymes and antioxidants, as well as hyaluronic acid, designed to help fibroblasts function more efficiently by providing a more optimal environment for biochemical processes and energy generation, as well as resisting the effects of oxidative stress. In vitro experiments suggest that there is a significant increase in the synthetic and prophylactic activity of fibroblasts with treated NCTF, and a significant increase in the ability of cells to resist oxidative stress. The current article looks at the rationale behind the development of polycomponent mesopreparations, using NCTF as an example. PMID:25897252

PAL-12, a new anti-aging hexa-peptoid, inhibits UVB-induced photoaging in human dermal fibroblasts and 3D reconstructed human full skin model, Keraskin-FT™.

PubMed

Song, Daeun; Park, Hyeonji; Lee, Su-Hyon; Kim, Mi Jung; Kim, Eun-Joo; Lim, Kyung-Min

2017-11-01

Peptoids are a class of peptidomimetics whose pharmacological activities are widely investigated owing to their remarkable biological stability. However, the utilities of peptoids as cosmetic functional ingredients have not been fully explored. Here, we investigated anti-aging effects of PAL-12, a new hexa-peptoid, on UVB-induced photoaging in human dermal fibroblasts (HDFs) and a 3D reconstituted human full skin model, Keraskin-FT™. PAL-12 suppressed matrix metalloproteinase-1 (MMP-1) expression induced by UVB irradiation along with the attenuation of MMP-1 secretion as determined by ELISA assay. Interestingly PAL-12 slightly enhanced the expression levels of collagen-1 and fibronectin-1 in HDFs or Keraskin-FT™. In addition, PAL-12 prevented the decrease of cell viability following UVB irradiation. However, PAL-12 failed to affect ROS generation, cell necrosis and apoptosis significantly. Instead, PAL-12 suppressed UVB-induced activation of epidermal growth factor receptors (EGFR), extracellular signal-regulated kinase (ERK) and c-Jun, which may resulted in the attenuation of AP-1-promoted MMP-1 expression. Collectively, these results suggest that PAL-12 might be a novel cosmetic ingredient effective against UVB-induced skin photoaging.

Multivariate Models for Prediction of Human Skin Sensitization ...

EPA Pesticide Factsheets

One of the lnteragency Coordinating Committee on the Validation of Alternative Method's (ICCVAM) top priorities is the development and evaluation of non-animal approaches to identify potential skin sensitizers. The complexity of biological events necessary to produce skin sensitization suggests that no single alternative method will replace the currently accepted animal tests. ICCVAM is evaluating an integrated approach to testing and assessment based on the adverse outcome pathway for skin sensitization that uses machine learning approaches to predict human skin sensitization hazard. We combined data from three in chemico or in vitro assays - the direct peptide reactivity assay (DPRA), human cell line activation test (h-CLAT) and KeratinoSens TM assay - six physicochemical properties and an in silico read-across prediction of skin sensitization hazard into 12 variable groups. The variable groups were evaluated using two machine learning approaches , logistic regression and support vector machine, to predict human skin sensitization hazard. Models were trained on 72 substances and tested on an external set of 24 substances. The six models (three logistic regression and three support vector machine) with the highest accuracy (92%) used: (1) DPRA, h-CLAT and read-across; (2) DPRA, h-CLAT, read-across and KeratinoSens; or (3) DPRA, h-CLAT, read-across, KeratinoSens and log P. The models performed better at predicting human skin sensitization hazard than the murine

Effects of intrinsic aging and photodamage on skin dyspigmentation: an explorative study

NASA Astrophysics Data System (ADS)

Dobos, Gabor; Trojahn, Carina; D'Alessandro, Brian; Patwardhan, Sachin; Canfield, Douglas; Blume-Peytavi, Ulrike; Kottner, Jan

2016-06-01

Photoaging is associated with increasing pigmentary heterogeneity and darkening of skin color. However, little is known about age-related changes in skin pigmentation on sun-protected areas. The aim of this explorative study was to measure skin color and dyspigmentation using image processing and to evaluate the reliability of these parameters. Twenty-four volunteers of three age-groups were included in this explorative study. Measurements were conducted at sun-exposed and sun-protected areas. Overall skin-color estimates were similar among age groups. The hyper- and hypopigmentation indices differed significantly by age groups and their correlations with age ranged between 0.61 and 0.74. Dorsal forearm skin differed from the other investigational areas (p<0.001). We observed an increase in dyspigmentation at all skin areas, including sun-protected skin areas, already in young adulthood. Associations between age and dyspigmentation estimates were higher compared to color parameters. All color and dyspigmentation estimates showed high reliability. Dyspigmentation parameters seem to be better biomarkers for UV damage than the overall color measurements.

A custom tailored model to investigate skin penetration in porcine skin and its comparison with human skin.

PubMed

Herbig, Michael E; Houdek, Pia; Gorissen, Sascha; Zorn-Kruppa, Michaela; Wladykowski, Ewa; Volksdorf, Thomas; Grzybowski, Stephan; Kolios, Georgios; Willers, Christoph; Mallwitz, Henning; Moll, Ingrid; Brandner, Johanna M

2015-09-01

Reliable models for the determination of skin penetration and permeation are important for the development of new drugs and formulations. The intention of our study was to develop a skin penetration model which (1) is viable and well supplied with nutrients during the period of the experiment (2) is mimicking human skin as far as possible, but still is independent from the problems of supply and heterogeneity, (3) can give information about the penetration into different compartments of the skin and (4) considers specific inter-individual differences in skin thickness. In addition, it should be quick and inexpensive (5) and without ethical implications (6). Using a chemically divers set of four topically approved active pharmaceutical ingredients (APIs), namely diclofenac, metronidazole, tazarotene, and terbinafine, we demonstrated that the model allows reliable determination of drug concentrations in different layers of the viable epidermis and dermis. For APIs susceptible for skin metabolism, the extent of metabolic transformation in epidermis and dermis can be monitored. Furthermore, a high degree of accordance in the ability for discrimination of skin concentrations of the substances in different layers was found in models derived from porcine and human skin. Viability, proliferation, differentiation and markers for skin barrier function were surveyed in the model. This model, which we call 'Hamburg model of skin penetration' is particularly suited to support a rational ranking and selection of dermatological formulations within drug development projects. Copyright © 2015 Elsevier B.V. All rights reserved.

The role of peroxisome proliferator-activated receptor-coactivator-1 gene in skin aging

PubMed Central

Aghaei, Shahrzad; Nilforoushzadeh, Mohammad Ali; Aghaei, Maryam

2016-01-01

Skin aging is a continuous process that exhibits fine and deep wrinkles, thin and transparent skin, loss of underlying fat, dry skin and itch, following decreased collagen and elastin synthesis. Both extrinsic and intrinsic agents are considered in the pathogenesis on skin aging. Extrinsic factors such as sun exposure, windy and dry weather, nutrition, and lifestyle may induce premature aging, toxic-free radicals, and reactive oxygen species due to decreasing normal function of mitochondria which play the major intrinsic factors in premature skin aging. One of the major genetic factors in mitochondrial function is peroxisome proliferator-activated receptor-coactivator-1 (PGC-1) gene. This factor could delay skin aging by increasing the mitochondrial biogenesis and replication and oxidative phosphorylation and so may induce free radical scavenging. This review is focused on intrinsic skin aging and the role of PGC-1 protein in decreasing effect of aging causes. PMID:27904582

Immune Cell-Supplemented Human Skin Model for Studying Fungal Infections.

PubMed

Kühbacher, Andreas; Sohn, Kai; Burger-Kentischer, Anke; Rupp, Steffen

2017-01-01

Human skin is a niche for various fungal species which either colonize the surface of this tissue as commensals or, primarily under conditions of immunosuppression, invade the skin and cause infection. Here we present a method for generation of a human in vitro skin model supplemented with immune cells of choice. This model represents a complex yet amenable tool to study molecular mechanisms of host-fungi interactions at human skin.

[The clinical use of cryopreserved human skin allografts for transplantation].

PubMed

Martínez-Flores, Francisco; Chacón-Gómez, María; Madinaveitia-Villanueva, Juan Antonio; Barrera-Lopez, Araceli; Aguirre-Cruz, Lucinda; Querevalu-Murillo, Walter

2015-01-01

The biological recovery of human skin allografts is the gold standard for preservation in Skin Banks. However, there is no worldwide consensus about specific allocation criteria for preserved human skin allografts with living cells. A report is presented on the results of 5 years of experience of using human skin allografts in burned patient in the Skin and Tissue Bank at the "Instituto Nacional de Rehabilitacion" The human skin allografts were obtained from multi-organ donors. processed and preserved at -80 °C for 12 months. Allocation criteria were performed according to blood type match, clinical history, and burned body surface. Up to now, the Skin and Tissue Bank at 'Instituto Nacional de Rehabilitacion" has processed and recovered 125,000 cm(2) of human skin allografts. It has performed 34 surgical implants on 21 burned patients. The average of burn body surface was 59.2%. More than two-thirds (67.7%) of recipients of skin allografts were matched of the same to type blood of the donor, and 66.6% survived after 126 days hospital stay. It is proposed to consider recipient's blood group as allocation criteria to assign tissue; and use human skin allografts on patiens affected with burns over 30% of body surface (according the "rule of the 9"). Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.

Evaluation of a Silicone Membrane as an Alternative to Human Skin for Determining Skin Permeation Parameters of Chemical Compounds.

PubMed

Uchida, Takashi; Yakumaru, Masafumi; Nishioka, Keisuke; Higashi, Yoshihiro; Sano, Tomohiko; Todo, Hiroaki; Sugibayashi, Kenji

2016-01-01

We evaluated the effectiveness of a silicone membrane as an alternative to human skin using the skin permeation parameters of chemical compounds. An in vitro permeation study using 15 model compounds was conducted, and permeation parameters comprising permeability coefficient (P), diffusion parameter (DL(-2)), and partition parameter (KL) were calculated from each permeation profile. Significant correlations were obtained in log P, log DL(-2), and log KL values between the silicone membrane and human skin. DL(-2) values of model compounds, except flurbiprofen, in the silicone membrane were independent of the lipophilicity of the model compounds and were 100-fold higher than those in human skin. For antipyrine and caffeine, which are hydrophilic, KL values in the silicone membrane were 100-fold lower than those in human skin, and P values, calculated as the product of a DL(-2) and KL, were similar. For lipophilic compounds, such as n-butyl paraben and flurbiprofen, KL values for silicone were similar to or 10-fold higher than those in human skin, and P values for silicone were 100-fold higher than those in human skin. Furthermore, for amphiphilic compounds with log Ko/w values from 0.5 to 3.5, KL values in the silicone membrane were 10-fold lower than those in human skin, and P values for silicone were 10-fold higher than those in human skin. The silicone membrane was useful as a human skin alternative in an in vitro skin permeation study. However, depending on the lipophilicity of the model compounds, some parameters may be over- or underestimated.

Relationship between arsenic skin lesions and the age of natural menopause

PubMed Central

2014-01-01

Background Chronic exposure to arsenic is associated with neoplastic, cardiovascular, endocrine, neuro-developmental disorders and can have an adverse effect on women’s reproductive health outcomes. This study examined the relationship between arsenic skin lesions (a hallmark sign of chronic arsenic poisoning) and age of natural menopause (final menopausal period) in populations with high levels of arsenic exposure in Bangladesh. Methods We compared menopausal age in two groups of women – with and without arsenic skin lesions; and presence of arsenic skin lesions was used as an indicator for chronic arsenic exposure. In a cross-sectional study, a total of 210 participants were randomly identified from two ongoing studies— participants with arsenic skin lesions were identified from an ongoing clinical trial and participants with no arsenic skin lesions were identified from an ongoing cohort study. Mean age of menopause between these two groups were calculated and compared. Multivariable linear regression was used to estimate the relationship between the status of the arsenic skin lesions and age of natural menopause in women. Results Women with arsenic skin lesions were 1.5 years younger (p <0.001) at the time of menopause compared to those without arsenic skin lesions. After adjusting with contraceptive use, body mass index, urinary arsenic level and family history of premature menopause, the difference between the groups’ age at menopause was 2.1 years earlier (p <0.001) for respondents with arsenic skin lesions. Conclusions The study showed a statistically significant association between chronic exposure to arsenic and age at menopause. Heavily exposed women experienced menopause two years earlier than those with lower or no exposure. PMID:24886424

Chicken skin virome analyzed by high-throughput sequencing shows a composition highly different from human skin.

PubMed

Denesvre, Caroline; Dumarest, Marine; Rémy, Sylvie; Gourichon, David; Eloit, Marc

2015-10-01

Recent studies show that human skin at homeostasis is a complex ecosystem whose virome include circular DNA viruses, especially papillomaviruses and polyomaviruses. To determine the chicken skin virome in comparison with human skin virome, a chicken swabs pool sample from fifteen indoor healthy chickens of five genetic backgrounds was examined for the presence of DNA viruses by high-throughput sequencing (HTS). The results indicate a predominance of herpesviruses from the Mardivirus genus, coming from either vaccinal origin or presumably asymptomatic infection. Despite the high sensitivity of the HTS method used herein to detect small circular DNA viruses, we did not detect any papillomaviruses, polyomaviruses, or circoviruses, indicating that these viruses may not be resident of the chicken skin. The results suggest that the turkey herpesvirus is a resident of chicken skin in vaccinated chickens. This study indicates major differences between the skin viromes of chickens and humans. The origin of this difference remains to be further studied in relation with skin physiology, environment, or virus population dynamics.

Penetration of Chlorhexidine into Human Skin ▿

PubMed Central

Karpanen, T. J.; Worthington, T.; Conway, B. R.; Hilton, A. C.; Elliott, T. S. J.; Lambert, P. A.

2008-01-01

This study evaluated a model of skin permeation to determine the depth of delivery of chlorhexidine into full-thickness excised human skin following topical application of 2% (wt/vol) aqueous chlorhexidine digluconate. Skin permeation studies were performed on full-thickness human skin using Franz diffusion cells with exposure to chlorhexidine for 2 min, 30 min, and 24 h. The concentration of chlorhexidine extracted from skin sections was determined to a depth of 1,500 μm following serial sectioning of the skin using a microtome and analysis by high-performance liquid chromatography. Poor penetration of chlorhexidine into skin following 2-min and 30-min exposures to chlorhexidine was observed (0.157 ± 0.047 and 0.077 ± 0.015 μg/mg tissue within the top 100 μm), and levels of chlorhexidine were minimal at deeper skin depths (less than 0.002 μg/mg tissue below 300 μm). After 24 h of exposure, there was more chlorhexidine within the upper 100-μm sections (7.88 ± 1.37 μg/mg tissue); however, the levels remained low (less than 1 μg/mg tissue) at depths below 300 μm. There was no detectable penetration through the full-thickness skin. The model presented in this study can be used to assess the permeation of antiseptic agents through various layers of skin in vitro. Aqueous chlorhexidine demonstrated poor permeation into the deeper layers of the skin, which may restrict the efficacy of skin antisepsis with this agent. This study lays the foundation for further research in adopting alternative strategies for enhanced skin antisepsis in clinical practice. PMID:18676882

Facial skin photo-aging and development of hyperpigmented spots from children to middle-aged Japanese woman.

PubMed

Takahashi, Y; Fukushima, Y; Kondo, K; Ichihashi, M

2017-11-01

Facial skin hyperpigmention caused by chronic sun exposure is a major skin complaint, however, its characteristics and influential factors are still limitedly known. A cross-sectional survey in healthy Japanese women aged from 6 to 62 years (n=169) was conducted using a facial image analyzer VISIA ™ for knowing onset age of hyperpigmented spot formation, its chronological changes, and influence of environmental factors. UV Pigmented Spot (PS) Score was positively correlated with age (R=.487, P=.000). Hyperpigmented spots appeared first around 18 years old in most subjects, and PS score remarkably increased at 20s then gradually increased by ages. The subjects with Skin Type I, one of the three grades of Japanese Skin Type (JST), whose melanin formation is genetically lower, showed higher PS score. A woman aged 31 years was subjected a weekly VISIA measurement for 2 years, and found no changes in the number, place, size and intensity of the pigment spots in this duration. Hyperpigmented spots developed in women over 20 years of age due to chronic sun exposure without sun protection during childhood and adolescent and it was stable afterwards, whose intensity was influenced by age and skin type. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Shift in skin microbiota of Western European women across aging.

PubMed

Jugé, Romain; Rouaud-Tinguely, Pauline; Breugnot, Josselin; Servaes, Katia; Grimaldi, Christine; Roth, Marie-Paule; Coppin, Hélène; Closs, Brigitte

2018-05-23

The objective of our study was to compare the microbiota diversity between two different age groups of Western European women. Skin-swab samples were collected directly on the forehead of 34 healthy Western European women: 17 younger (21-31 years old) and 17 older individuals (54-69 years old). Bacterial communities were evaluated using the 16S rRNA gene sequencing. Data revealed a higher alpha-diversity on the skin of older individuals compared to younger ones. Overall microbiota structure was different between the two age groups, as demonstrated by beta-diversity analysis, which also highlighted a high interpersonal variation within older individuals. Furthermore, taxonomic composition analysis showed both an increase of Proteobacteria and a decrease of Actinobacteria on the older skin. At the genus level, older skin exhibited a significant increase in Corynebacterium and a decrease in Propionibacterium relative abundance. Our study revealed a shift in the distribution of skin microbiota during chronological aging in Western European women. Altogether these results could become the basis to develop new approaches aiming to rebalance the skin microbiota, which is modified during the aging process. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

The Importance of Some Plant Extracts as Skin Anti-aging Resources: A Review.

PubMed

Yasin, Zaliyatun A M; Ibrahim, Fatimah; Rashid, Nurshamimi N; Razif, Muhammad F M; Yusof, Rohana

2017-01-01

Skin is the largest and most visible organ of the body. Many of its functions include temperature regulation, immunity from microorganisms, maintaining electrolyte balance, and protection from physical injuries, chemical agents and ultraviolet (UV) radiation. Aging occurs in every layer of the skin, primarily due to the degradation of its components. Induction of degradative enzymes and the abundant production of reactive oxygen species lead to skin aging. Understanding the complexity of skin structure and factors contributing to the skin aging will help us impede the aging process. Applications of anti-aging products are a common method to prevent or repair damages that lead to aging. This review will provide information on the causes and indicators of skin aging as well as examine studies that have used plants to produce anti-aging products. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Cyclooxygenase-2 inhibitors modulate skin aging in a catalytic activity-independent manner

PubMed Central

Lee, Mi Eun; Kim, So Ra; Lee, Seungkoo; Jung, Yu-Jin; Choi, Sun Shim; Kim, Woo Jin

2012-01-01

It has been proposed that the pro-inflammatory catalytic activity of cyclooxygenase-2 (COX-2) plays a key role in the aging process. However, it remains unclear whether the COX-2 activity is a causal factor for aging and whether COX-2 inhibitors could prevent aging. We here examined the effect of COX-2 inhibitors on aging in the intrinsic skin aging model of hairless mice. We observed that among two selective COX-2 inhibitors and one non-selective COX inhibitor studied, only NS-398 inhibited skin aging, while celecoxib and aspirin accelerated skin aging. In addition, NS-398 reduced the expression of p53 and p16, whereas celecoxib and aspirin enhanced their expression. We also found that the aging-modulating effect of the inhibitors is closely associated with the expression of type I procollagen and caveolin-1. These results suggest that pro-inflammatory catalytic activity of COX-2 is not a causal factor for aging at least in skin and that COX-2 inhibitors might modulate skin aging by regulating the expression of type I procollagen and caveolin-1. PMID:22771771

3D profilometric characterization of the aged skin surface using a skin replica and alicona Mex software.

PubMed

Pirisinu, Marco; Mazzarello, Vittorio

2016-05-01

The skin's surface is characterized by a network of furrows and wrinkles showing different height and depth. Different studies showed that processes such as aging, photo aging and cancer may alter dermal ultrastructure surface. The quantitative analysis of skin topography is a key point for understanding health condition of the skin. Here, for the first time, the skin fine structure was studied via a new approach where replica method was combined with Mex Alicona software and scanning electron microscopy (SEM). The skin texture of cheek and forearm were studied in 120 healthy sardinian volunteers. Patients were divided into three different aged groups. The skin areas of interest were reproduced by the silicone replica method, each replica was explored by SEM and digital images were taken. By using Mex Alicona software were created 3D imagine and a list of 24 surface texture parameters were obtained, of these the most representative were chosen in order to assess eventual changes between groups. The skin's texture of forearm and cheek showed a gradually loss of its typical polyhedric mesh with increasing age group. In particular, the photoexposition increased loss of dermal texture. At today, Alicona mex technology was exclusively used on palaeontology studies, our results showed that a deep analyze of skin texture was performed and support Mex alicona software as a new promising tool on dermatological research. This new analytical approach provided an easy and fast process to appreciate skin texture and its changes, by using high quality 3D dimension images. SCANNING 38:213-220, 2016. © 2015 Wiley Periodicals, Inc. © Wiley Periodicals, Inc.

Evaluation of drug and sunscreen permeation via skin irradiated with UVA and UVB: comparisons of normal skin and chronologically aged skin.

PubMed

Hung, Chi-Feng; Fang, Chia-Lang; Al-Suwayeh, Saleh A; Yang, Shih-Yung; Fang, Jia-You

2012-12-01

Ultraviolet (UV) exposure is the predominant cause of skin aging. A systematic evaluation of drug skin permeation via photoaged skin is lacking. The aim of this work was to investigate whether UVA and UVB affect absorption by the skin of drugs and sunscreens, including tetracycline, quercetin, and oxybenzone. The dorsal skin of nude mice was subjected to UVA (24 and 39 J/cm(2)) or UVB (150, 200, and 250 mJ/cm(2)) irradiation. Levels of skin water loss, erythema, and sebum were evaluated, and histological examinations of COX-2 and claudin-1 expressions were carried out. Permeation of the permeants into and through the skin was determined in vitro using a Franz cell. In vivo skin uptake was also evaluated. Senescent skin (24 weeks old) was used for comparison. Wrinkling and scaling were significant signs of skin treated with UVA and UVB, respectively. The level of claudin-1, an indicator of tight junctions (TJs), was reduced by UVA and UVB irradiation. UVA enhanced tetracycline and quercetin skin deposition by 11- and 2-fold, respectively. A similar enhancement was shown for flux profiles. Surprisingly, a lower UVA dose revealed greater enhancement compared to the higher dose. The skin deposition and flux of tetracycline both decreased with UVB exposure. UVB also significantly reduced quercetin flux. The skin absorption behavior of chronologically aged skin approximated that of the UVA group, with photoaged skin showing higher enhancement. UV generally exhibited a negligible effect on modulating oxybenzone permeation. Skin disruption produced by UV does not necessarily result in enhanced skin absorption. It depends on the UV wavelength, irradiated energy, and physicochemical properties of the permeant. To the best of our knowledge, this is the first report establishing drug permeation profiles for UV-irradiated skin. Copyright © 2012 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

HSP27 as a biomarker for predicting skin irritation in human skin and reconstructed organotypic skin model.

PubMed

Chen, Hongxia; Li, Shuhua; Meng, Tian; Zhang, Lei; Dai, Taoli; Xiang, Qi; Su, Zhijian; Zhang, Qihao; Huang, Yadong

2014-04-21

In vitro alternative tests aiming at replacing the traditional animal test for predicting the irritant potential of chemicals have been developed, but the assessing parameters or endpoints are still not sufficient. To discover novel endpoints for skin irritation responses, 2DE-based proteomics was used to analyze the protein expression in human skin exposed to sodium lauryl sulfate (SLS) following the test protocol of the European Centre for the Validation of Alternative Methods (ECVAM) in the present study. HSP27 was up-regulated most significantly among the eight identified proteins, consistent with our previous reports. Acid and basic chemicals were applied on human skin for further validation and results showed that the up-regulated expression of HSP27 was induced in 24h after the exposure. Skin-equivalent constructed with fibroblasts, basement membrane and keratinocytes was used to investigate the potential of HSP27 as a biomarker or additional endpoint for the hazard assessment of skin irritation. Our skin-equivalent (Reconstructed Organotypic Skin Model, ROSM) had excellent epidermal differentiation and was suitable for the skin irritation test. HSP27 also displayed an up-regulated expression in the ROSM in 24h after the irritants exposure for 15min. All these results suggest that HSP27 may represent a potential marker or additional endpoint for the hazard assessment of skin irritation caused by chemical products. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Reversal of skin aging with topical retinoids.

PubMed

Hubbard, Bradley A; Unger, Jacob G; Rohrich, Rod J

2014-04-01

Topical skin care and its place in plastic surgery today are often overlooked by clinicians formulating a plan for facial rejuvenation. Not only is it important to consider topical skin care as part of comprehensive care, but clinicians should also be educated with the data available in today's literature. This review aims to familiarize the reader with the biological processes of skin aging and evidence-based clinical outcomes afforded by various topical therapies. Furthermore, this review will focus on solar damage, the value of retinoids, and how they can be used in conjunction with forms of treatment such as chemical peel, dermabrasion, and lasers. Finally, guidelines will be provided to help the physician administer appropriate skin care based on the data presented.

Transcriptome and ultrastructural changes in dystrophic Epidermolysis bullosa resemble skin aging.

PubMed

Breitenbach, Jenny S; Rinnerthaler, Mark; Trost, Andrea; Weber, Manuela; Klausegger, Alfred; Gruber, Christina; Bruckner, Daniela; Reitsamer, Herbert A; Bauer, Johann W; Breitenbach, Michael

2015-06-01

The aging process of skin has been investigated recently with respect to mitochondrial function and oxidative stress. We have here observed striking phenotypic and clinical similarity between skin aging and recessive dystrophic Epidermolysis bullosa (RDEB), which is caused by recessive mutations in the gene coding for collagen VII,COL7A1. Ultrastructural changes, defects in wound healing, and inflammation markers are in part shared with aged skin. We have here compared the skin transcriptomes of young adults suffering from RDEB with that of sex- and age-matched healthy probands. In parallel we have compared the skin transcriptome of healthy young adults with that of elderly healthy donors. Quite surprisingly, there was a large overlap of the two gene lists that concerned a limited number of functional protein families. Most prominent among the proteins found are a number of proteins of the cornified envelope or proteins mechanistically involved in cornification and other skin proteins. Further, the overlap list contains a large number of genes with a known role in inflammation. We are documenting some of the most prominent ultrastructural and protein changes by immunofluorescence analysis of skin sections from patients, old individuals, and healthy controls.

Fourier transform Raman spectroscopic studies of human and animal skins

NASA Astrophysics Data System (ADS)

Barry, Brian W.; Edwards, Howell G.; Williams, Adrian C.

1994-01-01

The stratum corneum is the outermost layer of the skin and provides the principal barrier for the ingress of chemicals and environmental toxins into human and animal tissues. However, human skin has several advantages for the administration of therapeutic agents (transdermal drug delivery), but problems occur with the supply, storage, and biohazardous nature of human tissue. Hence, alternative animal tissues have been prepared to model drug diffusion across human skin but the molecular basis for comparison is lacking. Here, FT-Raman spectra of mammalian (human and pig) and reptilian (snake) skins have been obtained and the structural dissimilarities are correlated with drug diffusion studies across the tissues.

Analyses of changes on skin by aging.

PubMed

Kazanci, A; Kurus, M; Atasever, A

2017-02-01

This study aimed to evaluate the histological changes occurring in rat skin with increasing age, starting from the intrauterine period. Thirty-two healthy female Sprague-Dawley rats were evaluated in four groups: group 1 - intrauterine day 19, group 2 - postpartum day 21, group 3 - postpartum day 60, and group 4 - postpartum month 19. Skin samples from the back, abdomen, head, and upper and lower limbs were obtained from each subject under anesthesia. Tissue specimens were evaluated statistically and morphologically for the thicknesses of the epidermis, dermis, and basement membrane; the number, height, and width of dermal papillae; and the mast cell and pilosebaceous counts per group. The changes in collagen/elastic fibers and glycosaminoglycans were also assessed. Epidermal thickness was the highest in the intrauterine group; it decreased in the postpartum period and increased again in the aged group. Basal membrane thickness increased steadily with age. The number, height, and width of dermal papillae and dermal thickness increased up to day 60 after birth although these decreased in the aged group. Mast cell count also reached the maximum in the intrauterine group and gradually decreased with age. Pilosebaceous units of the dermis were fewer in intrauterine specimens; they showed an increase during the postpartum period and a decrease in the aged group. Skin specimens obtained from rats showed striking differences between the intrauterine and postpartum groups. Moreover, the postpartum group showed considerable intra-group differences. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Visible skin colouration predicts perception of male facial age, health and attractiveness.

PubMed

Fink, B; Bunse, L; Matts, P J; D'Emiliano, D

2012-08-01

Although there is evidence that perception of facial age, health and attractiveness is informed by shape characteristics as well as by visible skin condition, studies on the latter have focused almost exclusively on female skin. Recent research, however, suggests that a decrease in skin colour homogeneity leads to older, less healthy and less attractive ratings of facial skin in both women and men. Here, we elaborate on the significance of the homogeneity of visible skin colouration in men by testing the hypothesis that perception of age, health and attractiveness of (non-contextual) digitally isolated fields of cheek skin only can predict that of whole facial images. Facial digital images of 160 British men (all Caucasian) aged between 10 and 70 were blind-rated for age, health and attractiveness by a total of 147 men and 154 women (mean age = 22.95, SD = 4.26), and these ratings were related to those of corresponding images of cheek skin reported by Fink et al. (J. Eur. Acad. Dermatol. Venereol. in press). Linear regression analysis showed that age, health and attractiveness perception of men's faces could be predicted by the ratings of cheek skin only, such that older men were viewed as older, less healthy and less attractive. This result underlines once again the potent signalling role of skin in its own right, independent of shape or other factors and suggests strongly that visible skin condition, and skin colour homogeneity in particular, plays a significant role in the perception of men's faces. © 2012 The Authors. ICS © 2012 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Molecular-level insights into aging processes of skin elastin.

PubMed

Mora Huertas, Angela C; Schmelzer, Christian E H; Hoehenwarter, Wolfgang; Heyroth, Frank; Heinz, Andrea

2016-01-01

Skin aging is characterized by different features including wrinkling, atrophy of the dermis and loss of elasticity associated with damage to the extracellular matrix protein elastin. The aim of this study was to investigate the aging process of skin elastin at the molecular level by evaluating the influence of intrinsic (chronological aging) and extrinsic factors (sun exposure) on the morphology and susceptibility of elastin towards enzymatic degradation. Elastin was isolated from biopsies derived from sun-protected or sun-exposed skin of differently aged individuals. The morphology of the elastin fibers was characterized by scanning electron microscopy. Mass spectrometric analysis and label-free quantification allowed identifying differences in the cleavage patterns of the elastin samples after enzymatic digestion. Principal component analysis and hierarchical cluster analysis were used to visualize differences between the samples and to determine the contribution of extrinsic and intrinsic aging to the proteolytic susceptibility of elastin. Moreover, the release of potentially bioactive peptides was studied. Skin aging is associated with the decomposition of elastin fibers, which is more pronounced in sun-exposed tissue. Marker peptides were identified, which showed an age-related increase or decrease in their abundances and provide insights into the progression of the aging process of elastin fibers. Strong age-related cleavage occurs in hydrophobic tropoelastin domains 18, 20, 24 and 26. Photoaging makes the N-terminal and central parts of the tropoelastin molecules more susceptible towards enzymatic cleavage and, hence, accelerates the age-related degradation of elastin. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

[Short peptides stimulate skin cell regeneration during ageing].

PubMed

Chalisova, N I; Lin'kova, N S; Zhekalov, A N; Orlova, A O; Ryzhak, G A; Khavinson, V Kh

2014-01-01

The actual goal of gerontocosmetology is deal with the research of new effective and harmless low- molecular substances. The influence of LK and AEDG peptides in concentrations 0.05-2.00 ng/ml on organotypic skin cell cultures proliferation in young and old animals were investigated. Peptides stimulated skin fibroblasts proliferation on 29-45% in skin cell cultures of young and old rats. This effect was observed in smaller concentration diapason and level during skin ageing in old cell cultures as compared to young cell cultures. These data open new approach for creation cosmetology substances in the base of LKand AEDG peptides.

In-vivo Reflectance Measurements from Human Skin

NASA Astrophysics Data System (ADS)

Delgado, J. A.; Cornejo, A.; Cunill, M.; Báez, J. J.; Matos, R.; Anasagasti, L.; Santiago, C.

2006-09-01

We evaluate the potential of using a standard commercial spectrophotometer, specifically designed to meet the growing requirement for color control in the digital-imaging application field, to perform in-vivo diffuse reflectance measurements from adult human skin. We report and discuss diffuse reflectance spectra for three practical situations: a) reflectance versus skin type, b) reflectance from normal skin with different grade of solar exposition, c) reflectance from normal skin versus reflectance from seborrheic keratosis. Results show, that using the above spectrophotometer we can easily differentiate two sites of different solar exposition. Besides, significant differences are found in the normal skin diffuse reflectance for patients with different skin types.

Multivariate Models for Prediction of Human Skin Sensitization Hazard

PubMed Central

Strickland, Judy; Zang, Qingda; Paris, Michael; Lehmann, David M.; Allen, David; Choksi, Neepa; Matheson, Joanna; Jacobs, Abigail; Casey, Warren; Kleinstreuer, Nicole

2016-01-01

One of ICCVAM’s top priorities is the development and evaluation of non-animal approaches to identify potential skin sensitizers. The complexity of biological events necessary to produce skin sensitization suggests that no single alternative method will replace the currently accepted animal tests. ICCVAM is evaluating an integrated approach to testing and assessment based on the adverse outcome pathway for skin sensitization that uses machine learning approaches to predict human skin sensitization hazard. We combined data from three in chemico or in vitro assays—the direct peptide reactivity assay (DPRA), human cell line activation test (h-CLAT), and KeratinoSens™ assay—six physicochemical properties, and an in silico read-across prediction of skin sensitization hazard into 12 variable groups. The variable groups were evaluated using two machine learning approaches, logistic regression (LR) and support vector machine (SVM), to predict human skin sensitization hazard. Models were trained on 72 substances and tested on an external set of 24 substances. The six models (three LR and three SVM) with the highest accuracy (92%) used: (1) DPRA, h-CLAT, and read-across; (2) DPRA, h-CLAT, read-across, and KeratinoSens; or (3) DPRA, h-CLAT, read-across, KeratinoSens, and log P. The models performed better at predicting human skin sensitization hazard than the murine local lymph node assay (accuracy = 88%), any of the alternative methods alone (accuracy = 63–79%), or test batteries combining data from the individual methods (accuracy = 75%). These results suggest that computational methods are promising tools to effectively identify potential human skin sensitizers without animal testing. PMID:27480324

The underlying mechanism of proinflammatory NF-κB activation by the mTORC2/Akt/IKKα pathway during skin aging

PubMed Central

Choi, Yeon Ja; Moon, Kyoung Mi; Chung, Ki Wung; Jeong, Ji Won; Park, Daeui; Kim, Dae Hyun; Yu, Byung Pal; Chung, Hae Young

2016-01-01

Mammalian target of rapamycin complex 2 (mTORC2), one of two different enzymatic complexes of mTOR, regulates a diverse set of substrates including Akt. mTOR pathway is one of well-known mediators of aging process, however, its role in skin aging has not been determined. Skin aging can be induced by physical age and ultraviolet (UV) irradiation which are intrinsic and extrinsic factors, respectively. Here, we report increased mTORC2 pathway in intrinsic and photo-induced skin aging, which is implicated in the activation of nuclear factor-κB (NF-κB). UVB-irradiated or aged mice skin revealed that mTORC2 activity and its component, rictor were significantly upregulated which in turn increased Akt activation and Akt-dependent IκB kinase α (IKKα) phosphorylation at Thr23 in vivo. We also confirmed that UVB induced the mTORC2/Akt/IKKα signaling pathway with HaCaT human normal keratinocytes. The increased mTORC2 signaling pathway during skin aging were associated to NF-κB activation. Suppression of mTORC2 activity by the treatment of a mTOR small inhibitor or knockdown of RICTOR partially rescued UVB-induced NF-κB activation through the downregulation of Akt/IKKα activity. Our data demonstrated the upregulation of mTORC2 pathway in intrinsic and photo-induced skin aging and its role in IKKα/NF-κB activation. These data not only expanded the functions of mTOR to skin aging but also revealed the therapeutic potential of inhibiting mTORC2 in ameliorating both intrinsic skin aging and photoaging. PMID:27486771

First genomic survey of human skin fungal diversity

Cancer.gov

Fungal infections of the skin affect 29 million people in the United States. In the first study of human fungal skin diversity, National Institutes of Health researchers sequenced the DNA of fungi that thrive at different skin sites of healthy adults to d

In vitro dermal absorption of pyrethroid pesticides in human and rat skin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hughes, Michael F., E-mail: hughes.michaelf@epa.go; Edwards, Brenda C.

2010-07-15

Dermal exposure to pyrethroid pesticides can occur during manufacture and application. This study examined the in vitro dermal absorption of pyrethroids using rat and human skin. Dermatomed skin from adult male Long Evans rats or human cadavers was mounted in flow-through diffusion cells, and radiolabeled bifenthrin, deltamethrin or cis-permethrin was applied in acetone to the skin. Fractions of receptor fluid were collected every 4 h. At 24 h, the skins were washed with soap and water to remove unabsorbed chemical. The skin was then solubilized. Two additional experiments were performed after washing the skin; the first was tape-stripping the skinmore » and the second was the collection of receptor fluid for an additional 24 h. Receptor fluid, skin washes, tape strips and skin were analyzed for radioactivity. For rat skin, the wash removed 53-71% of the dose and 26-43% remained in the skin. The cumulative percentage of the dose at 24 h in the receptor fluid ranged from 1 to 5%. For human skin, the wash removed 71-83% of the dose and 14-25% remained in the skin. The cumulative percentage of the dose at 24 h in the receptor fluid was 1-2%. Tape-stripping removed 50-56% and 79-95% of the dose in rat and human skin, respectively, after the wash. From 24-48 h, 1-3% and about 1% of the dose diffused into the receptor fluid of rat and human skin, respectively. The pyrethroids bifenthrin, deltamethrin and cis-permethrin penetrated rat and human skin following dermal application in vitro. However, a skin wash removed 50% or more of the dose from rat and human skin. Rat skin was more permeable to the pyrethroids than human skin. Of the dose in skin, 50% or more was removed by tape-stripping, suggesting that permeation of pyrethroids into viable tissue could be impeded. The percentage of the dose absorbed into the receptor fluid was considerably less than the dose in rat and human skin. Therefore, consideration of the skin type used and fractions analyzed are important

Cohabitation--relationships of corynebacteria and staphylococci on human skin.

PubMed

Kwaszewska, Anna; Sobiś-Glinkowska, Maria; Szewczyk, Eligia M

2014-11-01

Skin microbiome main cultivable aerobes in human are coagulase-negative staphylococci and lipophilic corynebacteria. Staphylococcus strains (155) belonging to 10 species and 105 strains of Corynebacterium belonging to nine species from the skin swabs of healthy male volunteers were investigated to determine their enzymatic activity to main metabolic substrates: carbohydrates, proteins, lipids, and response to factors present on the skin such as osmotic pressure, pH, and organic acids. The results showed that lipophilic corynebacteria have different capacity for adaptation on the skin than staphylococci. Most of Corynebacterium spp. expressed lack of proteinase, phospholipase, and saccharolytic enzymes activity. Corynebacteria were also more sensitive than Staphylococcus spp. to antimicrobial agents existing on human skin, especially to low pH. These characters can explain domination of Staphylococcus genera on healthy human skin. It can be suggested that within these two bacterial genus, there exists conceivable cooperation and reciprocal protection which results in their quantitative ratio. Such behavior must be considered as crucial for the stability of the population on healthy skin.

The influence of age and gender on skin-associated microbial communities in urban and rural human populations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ying, Shi; Zeng, Dan -Ning; Chi, Liang

Differences in the bacterial community structure associated with 7 skin sites in 71 healthy people over five days showed significant correlations with age, gender, physical skin parameters, and whether participants lived in urban or rural locations in the same city. While body site explained the majority of the variance in bacterial community structure, the composition of the skin-associated bacterial communities were predominantly influenced by whether the participants were living in an urban or rural environment, with a significantly greater relative abundance of Trabulsiella in urban populations. Adults maintained greater overall microbial diversity than adolescents or the elderly, while the intragroupmore » variation among the elderly and rural populations was significantly greater. Lastly, skin-associated bacterial community structure and composition could predict whether a sample came from an urban or a rural resident ~ 5x greater than random.« less

The influence of age and gender on skin-associated microbial communities in urban and rural human populations

DOE PAGES

Ying, Shi; Zeng, Dan -Ning; Chi, Liang; ...

2015-10-28

Differences in the bacterial community structure associated with 7 skin sites in 71 healthy people over five days showed significant correlations with age, gender, physical skin parameters, and whether participants lived in urban or rural locations in the same city. While body site explained the majority of the variance in bacterial community structure, the composition of the skin-associated bacterial communities were predominantly influenced by whether the participants were living in an urban or rural environment, with a significantly greater relative abundance of Trabulsiella in urban populations. Adults maintained greater overall microbial diversity than adolescents or the elderly, while the intragroupmore » variation among the elderly and rural populations was significantly greater. Lastly, skin-associated bacterial community structure and composition could predict whether a sample came from an urban or a rural resident ~ 5x greater than random.« less

[The role of free radicals in the UV-induced skin damage. Photo-aging].

PubMed

Emri, Gabriella; Horkay, Irén; Remenyik, Eva

2006-04-23

The natural (intrinsic) ageing of the skin is enhanced by environmental factors (extrinsic ageing). One of the most important exogenous factors is the solar UV exposure, which results in photo-aging. Besides this, epidemiological and experimental data show a rapid increase in the incidence of human skin cancers, which is also in relation to the increased sunlight exposure of the skin. In the background of these processes there are cell biological effects, photochemical reactions, membrane receptor changes, lipid- and protein modifications, DNA-damage induced by UV. The qualities and quantities of them are wavelength dependent. The UVB photons are absorbed mostly by the DNA of the epidermal keratinocytes, therefore this spectrum is more relevant for photocarcinogenesis. The effect of UVA-irradiation is mainly manifested in the induction of free radicals, which have not only DNA-damaging, but also immunomodulating effect, which also can influence on tumour development. Furthermore, the free radicals cause dermal connective tissue damage as well via activating transcription factors, inducing matrix metalloproteinases, diminishing the procollagen I and fibrillin-1 synthesis. These processes are augmented by mitochondrial DNA mutations, protein oxidation, apoptosis induction. Therefore the enzymes neutralising free radicals and antioxidant molecules, respectively, have an important role in the defence mechanisms. In the therapy of photo-aging the local retinoids lived up to expectations, but the clinical effectiveness of antioxidant vitamins is lower than expected. The most important factor in the prevention of the photo-aging and photocarcinogenesis is the sun protection at present.

Atomic hydrogen surrounded by water molecules, H(H2O)m, modulates basal and UV-induced gene expressions in human skin in vivo.

PubMed

Shin, Mi Hee; Park, Raeeun; Nojima, Hideo; Kim, Hyung-Chel; Kim, Yeon Kyung; Chung, Jin Ho

2013-01-01

Recently, there has been much effort to find effective ingredients which can prevent or retard cutaneous skin aging after topical or systemic use. Here, we investigated the effects of the atomic hydrogen surrounded by water molecules, H(H2O)m, on acute UV-induced responses and as well as skin aging. Interestingly, we observed that H(H2O)m application to human skin prevented UV-induced erythema and DNA damage. And H(H2O)m significantly prevented UV-induced MMP-1, COX-2, IL-6 and IL-1β mRNA expressions in human skin in vivo. We found that H(H2O)m prevented UV-induced ROS generation and inhibited UV-induced MMP-1, COX-2 and IL-6 expressions, and UV-induced JNK and c-Jun phosphorylation in HaCaT cells. Next, we investigated the effects of H(H2O)m on intrinsically aged or photoaged skin of elderly subjects. In intrinsically aged skin, H(H2O)m application significantly reduced constitutive expressions of MMP-1, IL-6, and IL-1β mRNA. Additionally, H(H2O)m significantly increased procollagen mRNA and also decreased MMP-1 and IL-6 mRNA expressions in photoaged facial skin. These results demonstrated that local application of H(H2O)m may prevent UV-induced skin inflammation and can modulate intrinsic skin aging and photoaging processes. Therefore, we suggest that modifying the atmospheric gas environment within a room may be a new way to regulate skin functions or skin aging.

Atomic Hydrogen Surrounded by Water Molecules, H(H2O)m, Modulates Basal and UV-Induced Gene Expressions in Human Skin In Vivo

PubMed Central

Shin, Mi Hee; Park, Raeeun; Nojima, Hideo; Kim, Hyung-Chel; Kim, Yeon Kyung; Chung, Jin Ho

2013-01-01

Recently, there has been much effort to find effective ingredients which can prevent or retard cutaneous skin aging after topical or systemic use. Here, we investigated the effects of the atomic hydrogen surrounded by water molecules, H(H2O)m, on acute UV-induced responses and as well as skin aging. Interestingly, we observed that H(H2O)m application to human skin prevented UV-induced erythema and DNA damage. And H(H2O)m significantly prevented UV-induced MMP-1, COX-2, IL-6 and IL-1β mRNA expressions in human skin in vivo. We found that H(H2O)m prevented UV-induced ROS generation and inhibited UV-induced MMP-1, COX-2 and IL-6 expressions, and UV-induced JNK and c-Jun phosphorylation in HaCaT cells. Next, we investigated the effects of H(H2O)m on intrinsically aged or photoaged skin of elderly subjects. In intrinsically aged skin, H(H2O)m application significantly reduced constitutive expressions of MMP-1, IL-6, and IL-1β mRNA. Additionally, H(H2O)m significantly increased procollagen mRNA and also decreased MMP-1 and IL-6 mRNA expressions in photoaged facial skin. These results demonstrated that local application of H(H2O)m may prevent UV-induced skin inflammation and can modulate intrinsic skin aging and photoaging processes. Therefore, we suggest that modifying the atmospheric gas environment within a room may be a new way to regulate skin functions or skin aging. PMID:23637886

Influence of facial skin ageing characteristics on the perceived age in a Russian female population.

PubMed

Merinville, E; Grennan, G Z; Gillbro, J M; Mathieu, J; Mavon, A

2015-10-01

The desire for a youthful look remains a powerful motivator in the purchase of cosmetics by women globally. To develop an anti-ageing solution that targets the need of end consumers, it is critical to understand which signs of ageing really matter to them and which influence their age perception. To date, such research has not been performed in a Russian population. The aim of this work was to identify the signs of ageing that contribute the most to an 'older' or 'younger' look for Russian women aged 40 years old and above. The age of 203 Russian female volunteers was estimated from their standard photographs by a total of 629 female naïve assessors aged 20-65 years old. Perceived age data were related to 23 facial skin features previously measured using linear correlation coefficients. Differences in average severity of the correlating skin ageing features were evaluated between women perceived older and women perceived younger than their chronological age. Volunteers' responses to a ranking question on their key ageing skin concerns previously collected were analysed to provide an additional view on facial ageing from the consumer perspective. Nine facial skin ageing features were found to correlate the most with perceived age out of the 23 measured. Such results showed the importance of wrinkles in the upper part of the face (crow's feet, glabellar, under eye and forehead wrinkles), but also wrinkles in the lower half of the face associated with facial sagging (upper lip, nasolabial fold). Sagging was confirmed of key importance to female volunteers aged 41-65 years old who were mostly concerned by the sagging of their jawline, ahead of under eye and crow's feet wrinkle. The severity of hyperpigmented spots, red and brown, was also found to contribute to perceived age although to a weaker extent. By providing a clear view on the signs of ageing really matter to Russian women who are aged 40 years old and above, this research offers key information for the

UV radiation induces CXCL5 expression in human skin.

PubMed

Reichert, Olga; Kolbe, Ludger; Terstegen, Lara; Staeb, Franz; Wenck, Horst; Schmelz, Martin; Genth, Harald; Kaever, Volkhard; Roggenkamp, Dennis; Neufang, Gitta

2015-04-01

CXCL5 has recently been identified as a mediator of UVB-induced pain in rodents. To compare and to extend previous knowledge of cutaneous CXCL5 regulation, we performed a comprehensive study on the effects of UV radiation on CXCL5 regulation in human skin. Our results show a dose-dependent increase in CXCL5 protein in human skin after UV radiation. CXCL5 can be released by different cell types in the skin. We presumed that, in addition to immune cells, non-immune skin cells also contribute to UV-induced increase in CXCL5 protein. Analysis of monocultured dermal fibroblasts and keratinocytes revealed that only fibroblasts but not keratinocytes displayed up regulated CXCL5 levels after UV stimulation. Whereas UV treatment of human skin equivalents, induced epidermal CXCL5 mRNA and protein expression. Up regulation of epidermal CXCL5 was independent of keratinocyte differentiation and keratinocyte-keratinocyte interactions in epidermal layers. Our findings provide first evidence on the release of CXCL5 in UV-radiated human skin and the essential role of fibroblast-keratinocyte interaction in the regulation of epidermal CXCL5. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A novel image-based BRDF measurement system and its application to human skin

NASA Astrophysics Data System (ADS)

Bintz, Jeffrey R.; Mendenhall, Michael J.; Marciniak, Michael A.; Butler, Samuel D.; Lloyd, James Tommy

2016-09-01

Human skin detection is an important first step in search and rescue (SAR) scenarios. Previous research performed human skin detection through an application specific camera system that ex- ploits the spectral properties of human skin at two visible and two near-infrared (NIR) wavelengths. The current theory assumes human skin is diffuse; however, it is observed that human skin exhibits specular and diffuse reflectance properties. This paper presents a novel image-based bidirectional reflectance distribution function (BRDF) measurement system, and applies it to the collection of human skin BRDF. The system uses a grid projecting laser and a novel signal processing chain to extract the surface normal from each grid location. Human skin BRDF measurements are shown for a variety of melanin content and hair coverage at the four spectral channels needed for human skin detection. The NIR results represent a novel contribution to the existing body of human skin BRDF measurements.

Systematic Review and Meta-Analysis of Human Skin Diseases Due to Particulate Matter.

PubMed

Ngoc, Le Thi Nhu; Park, Duckshin; Lee, Yongil; Lee, Young-Chul

2017-11-25

This study investigated the effects of particulate matter (PM) on human skin diseases by conducting a systematic review of existing literature and performing a meta-analysis. It considered articles reporting an original effect of PM on human skin. From among 918 articles identified, 13 articles were included for further consideration after manual screening of the articles resulted in the exclusion of articles that did not contain data, review articles, editorials, and also articles in languages other than English. Random-effects models and forest plots were used to estimate the effect of PM on the skin by Meta-Disc analysis. According to people's reports of exposure and negative skin effects (atopic dermatitis (AD), eczema, and skin aging, etc.) due to air pollution, the summary relative risk (odds ratio) of PM 10 was determined to be 0.99 (95% confidence interval (CI) 0.89-1.11) whereas PM 2.5 was determined to be 1.04 (95% CI 0.96-1.12). Simultaneously, there was a different extent of impact between PM 10 and PM 2.5 on atopic dermatitis (AD) for those of young age: the odds ratio of PM 10 and PM 2.5 were 0.96 (95% CI 0.83-1.11; I² = 62.7%) and 1.05 (95% CI 0.95-1.16; I² = 46%), respectively. Furthermore, the results suggest an estimated increase of disease incidence per 10 μg/m³ PM of 1.01% (0.08-2.05) due to PM 10 and 1.60% (0.45-2.82) due to PM 2.5 . Following the results, PM 10 and PM 2.5 are associated with increased risks of human skin diseases, especially AD, whose risk is higher in infants and school children. With its smaller size and a high concentration of metals, PM 2.5 is more closely related to AD in younger people, compared to PM 10 .

Multiple-reflection model of human skin and estimation of pigment concentrations

NASA Astrophysics Data System (ADS)

Ohtsuki, Rie; Tominaga, Shoji; Tanno, Osamu

2012-07-01

We describe a new method for estimating the concentrations of pigments in the human skin using surface spectral reflectance. We derive an equation that expresses the surface spectral reflectance of the human skin. First, we propose an optical model of the human skin that accounts for the stratum corneum. We also consider the difference between the scattering coefficient of the epidermis and that of the dermis. We then derive an equation by applying the Kubelka-Munk theory to an optical model of the human skin. Unlike a model developed in a recent study, the present equation considers pigments as well as multiple reflections and the thicknesses of the skin layers as factors that affect the color of the human skin. In two experiments, we estimate the pigment concentrations using the measured surface spectral reflectances. Finally, we confirm the feasibility of the concentrations estimated by the proposed method by evaluating the estimated pigment concentrations in the skin.

Skin aging: molecular pathology, dermal remodelling and the imaging revolution.

PubMed

Newton, V L; Mcconnell, J C; Hibbert, S A; Graham, H K; Watson, R E

2015-12-01

Skin is a multifunctional organ but, alongside every other organ system, is subject to both intrinsic (chronological) and extrinsic (environmental) aging, resulting in a loss of functional capacity. Cutaneous aging manifests as an observable change in the external appearance of the skin, the major accelerator of the aging process being our interactions with our environment, such as chronic exposure to solar irradiation (UV, IR or visible wavelengths of light). The aim of this contribution, therefore, was to provide a review of the pathological mechanisms which may play roles in the development of extrinsic, mainly photo-, aging and to review how these molecular changes impact on the structure of the organ as a whole, resulting in loss of function. Finally, we will describe the advances which are occurring in imaging techniques which may allow further characterisation of aged skin.

Large-scale human skin lipidomics by quantitative, high-throughput shotgun mass spectrometry.

PubMed

Sadowski, Tomasz; Klose, Christian; Gerl, Mathias J; Wójcik-Maciejewicz, Anna; Herzog, Ronny; Simons, Kai; Reich, Adam; Surma, Michal A

2017-03-07

The lipid composition of human skin is essential for its function; however the simultaneous quantification of a wide range of stratum corneum (SC) and sebaceous lipids is not trivial. We developed and validated a quantitative high-throughput shotgun mass spectrometry-based platform for lipid analysis of tape-stripped SC skin samples. It features coverage of 16 lipid classes; total quantification to the level of individual lipid molecules; high reproducibility and high-throughput capabilities. With this method we conducted a large lipidomic survey of 268 human SC samples, where we investigated the relationship between sampling depth and lipid composition, lipidome variability in samples from 14 different sampling sites on the human body and finally, we assessed the impact of age and sex on lipidome variability in 104 healthy subjects. We found sebaceous lipids to constitute an abundant component of the SC lipidome as they diffuse into the topmost SC layers forming a gradient. Lipidomic variability with respect to sampling depth, site and subject is considerable, and mainly accredited to sebaceous lipids, while stratum corneum lipids vary less. This stresses the importance of sampling design and the role of sebaceous lipids in skin studies.

Histologic Changes Caused by Application of Lewisite Analogs to Mouse Skin and Human Skin Xenografts

DTIC Science & Technology

1985-01-01

CLASSIICATION OF THIS PAGE (Nh..1 DO&a Eatat1d UNCLAS8inED S6CURmTV CLASSISCATION OP THIS PA•r(em Daf EMo* skin grafts : 1) epidermal cellular nuclear...microscopy. Under light microscopy, we observed the following changes In PDA-treated human skin grafts : I) epidermal cellular nuclear degeneration (apparent...needed. (Oe such model is ti-e human skin grafted athymic nude mouse (4,5). This animal model was recently established at LAIR. PhenyLdichLoroarsine (PDA

'Nosing Around' the human skin: what information is concealed in skin odour?

PubMed

Kippenberger, Stefan; Havlíček, Jan; Bernd, August; Thaçi, Diamant; Kaufmann, Roland; Meissner, Markus

2012-09-01

In today's world, natural body odour is mostly considered as being unpleasant and combated by intensive cleansing, deodorants and perfumes. However, there is evidence that volatile body compounds provide the recipient with important information. Here, we present the chemical identity of odorous compounds derived from odourless precursors within sweat and sebum. Moreover, distinct volatile markers may be relevant for the clinical diagnosis of disease. Interestingly, ageing seems to correlate with the appearance of specific compounds that convey the so-called old man smell. Finally, it is discussed if human skin odour has the quality to act as pheromone transmitting information between individuals in terms of major histocompatibility complex type or reproductive status. © 2012 John Wiley & Sons A/S.

Factors associated with premature skin aging (photoaging) before the age of 55: a population-based study.

PubMed

Green, A C; Hughes, M C B; McBride, P; Fourtanier, A

2011-02-01

Precise factors associated with premature skin aging, or photoaging, in the general population are unknown. To examine the risk factors for photoaging in a Queensland community. A cross-sectional study of 1,400 randomly selected residents aged 20-54 years, using casts of the back of the hand (surface microtopography) and dermatological assessment of photoaging. 83% of the participants had premature skin aging, worsening after the age of 30. Severe neck wrinkling was 3 times more likely in men and some 4 times more likely in fair-skinned people (odds ratio, OR=3.86, 95% confidence interval, CI=2.40-6.23). Red hair and mainly outdoor work or leisure raised the odds of microtopographic photoaging. Current smoking was strongly associated with facial comedones and telangiectasia, and among current smokers, the microtopography grade was significantly associated with moderate and heavy smoking measured by pack-years of exposure, with OR=3.18 (95% CI=1.38-7.35) in the heaviest (>20 pack-years) smoking category compared with 1-7 pack-years. Premature skin aging is common in the subtropics, more severe in men and the fair-skinned. It is associated with high sun exposure during leisure or work, and moderate to heavy smoking, and therefore is preventable. Copyright © 2010 S. Karger AG, Basel.

Lifestyle Factors and Visible Skin Aging in a Population of Japanese Elders

PubMed Central

Asakura, Keiko; Nishiwaki, Yuji; Milojevic, Ai; Michikawa, Takehiro; Kikuchi, Yuriko; Nakano, Makiko; Iwasawa, Satoko; Hillebrand, Greg; Miyamoto, Kukizo; Ono, Masaji; Kinjo, Yoshihide; Akiba, Suminori; Takebayashi, Toru

2009-01-01

Background The number of studies that use objective and quantitative methods to evaluate facial skin aging in elderly people is extremely limited, especially in Japan. Therefore, in this cross-sectional study we attempted to characterize the condition of facial skin (hyperpigmentation, pores, texture, and wrinkling) in Japanese adults aged 65 years or older by using objective and quantitative imaging methods. In addition, we aimed to identify lifestyle factors significantly associated with these visible signs of aging. Methods The study subjects were 802 community-dwelling Japanese men and women aged at least 65 years and living in the town of Kurabuchi (Takasaki City, Gunma Prefecture, Japan), a mountain community with a population of approximately 4800. The facial skin condition of subjects was assessed quantitatively using a standardized facial imaging system and subsequent computer image analysis. Lifestyle information was collected using a structured questionnaire. The association between skin condition and lifestyle factors was examined using multivariable regression analysis. Results Among women, the mean values for facial texture, hyperpigmentation, and pores were generally lower than those among age-matched men. There was no significant difference between sexes in the severity of facial wrinkling. Older age was associated with worse skin condition among women only. After adjusting for age, smoking status and topical sun protection were significantly associated with skin condition among both men and women. Conclusions Our study revealed significant differences between sexes in the severity of hyperpigmentation, texture, and pores, but not wrinkling. Smoking status and topical sun protection were significantly associated with signs of visible skin aging in this study population. PMID:19700917

Stimulating effects of Bacillus subtilis natto-fermented Radix astragali on hyaluronic acid production in human skin cells.

PubMed

Hsu, Mei-Fang; Chiang, Been-Huang

2009-09-25

Radix astragali, a well-known Chinese herb, which has been traditionally used for skincare, and microbial fermentation is one of the conventional methods for processing Chinese herbs. This research studied the effects of non-fermented (HQNB) and fermented preparations (HQB) of Radix astragali on hyaluronic acid (HA) production in primary human skin cells. HQB and HQNB were prepared and added to the cultures of primary human skin cells. Hyaluronic acid content was determined using ELISA. Real-time RT-PCR was used to evaluate hyaluronan synthase gene expression. The bioactive compounds were analyzed by HPLC. The growth-stimulating effect of HQNB on both of keratinocytes and fibroblasts were significantly higher than that of HQB. Conversely, HQB, but not HQNB significantly stimulated HA production in both cultured primary human epidermal keratinocytes and human dermal fibroblasts in dose-dependent manners. In addition, HQB markedly and dose-dependently increased the expression of hyaluronan synthase 3 and hyaluronan synthase 2 mRNA in HaCaT cells and human fibroblasts, respectively. Therefore, HQB might be a promising candidate for preventing the age-dependent loss of HA content in aged human skin, and its effect on the enhancement of HA synthesis in skin cells is highly related to its effect on the expression of hyaluronan synthase genes. The three major active isoflavonoids in Radix astragali were identified as ononin, calycosin, and formononetin. After fermentation, all of these three compounds in HQB were significantly reduced. However, HQB still had significantly higher enhancement effect on the production of HA than HQNB. It appeared that isoflavonoid aglycones or other metabolites, converted from their primary isoflavones during fermentation, might be responsible for the skincare functions found in this study. This study demonstrated the low toxicity and the stimulating effects of HQB on HA synthesis, and suggests that HQB may play a promising role in anti-aging

The immunology of the porcine skin and its value as a model for human skin.

PubMed

Summerfield, Artur; Meurens, François; Ricklin, Meret E

2015-07-01

The porcine skin has striking similarities to the human skin in terms of general structure, thickness, hair follicle content, pigmentation, collagen and lipid composition. This has been the basis for numerous studies using the pig as a model for wound healing, transdermal delivery, dermal toxicology, radiation and UVB effects. Considering that the skin also represents an immune organ of utmost importance for health, immune cells present in the skin of the pig will be reviewed. The focus of this review is on dendritic cells, which play a central role in the skin immune system as they serve as sentinels in the skin, which offers a large surface area exposed to the environment. Based on a literature review and original data we propose a classification of porcine dendritic cell subsets in the skin corresponding to the subsets described in the human skin. The equivalent of the human CD141(+) DC subset is CD1a(-)CD4(-)CD172a(-)CADM1(high), that of the CD1c(+) subset is CD1a(+)CD4(-)CD172a(+)CADM1(+/low), and porcine plasmacytoid dendritic cells are CD1a(-)CD4(+)CD172a(+)CADM1(-). CD209 and CD14 could represent markers of inflammatory monocyte-derived cells, either dendritic cells or macrophages. Future studies for example using transriptomic analysis of sorted populations are required to confirm the identity of these cells. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Frequency dispersions of human skin dielectrics.

PubMed Central

Poon, C S; Choy, T T

1981-01-01

The electrical properties of many biological materials are known to exhibit frequency dispersions. In the human skin, the impedance measured at various frequencies closely describes a circular locus of the Cole-Cole type in the complex impedance plane. In this report, the formative mechanisms responsible for the anomalous circular-arc behavior of skin impedance were investigated, using data from impedance measurements taken after successive strippings of the skin. The data were analyzed with respect to changes in the parameters of the equivalent Cole-Cole model after each stripping. For an exponential resistivity profile (Tregear, 1966, Physical Functions of Skin; Yamamoto and Yamamoto, 1976, Med. Biol. Eng., 14:151--158), the profile of the dielectric constant was shown to be uniform across the epidermis. Based on these results, a structural model has been formulated in terms of the relaxation theory of Maxwell and Wagner for inhomogeneous dielectric materials. The impedance locus obtained from the model approximates a circular are with phase constant alpha = 0.82, which compares favorably with experimental data. At higher frequencies a constant-phase, frequency-dependent component having the same phase constant alpha is also demonstrated. It is suggested that an approximately rectangular distribution of the relaxation time over the epidermal dielectric sheath is adequate to account for the anomalous frequency characteristics of human skin impedance. PMID:7213928

Bringing skin assessments to life using human patient simulation: an emphasis on cancer prevention and early detection.

PubMed

Kuhrik, Marilee; Seckman, Christy; Kuhrik, Nancy; Ahearn, Tina; Ercole, Patrick

2011-12-01

Skin cancer is the most common cancer in the United States, with about 1,000,000 people developing the disease each year. The incidence of melanoma has rapidly increased in young white women between the ages of 15-34 over the last three decades. While melanoma accounts for approximately 3% of skin cancers, it causes more than 75% of skin cancer deaths. Thorough skin assessments and awareness of new or changing appearance of skin lesions are critical to early detection and treatment of skin cancer, as well as teaching sun-protective behaviors. Educators created a novel approach to "bring to life" skin cancer assessment skills to promote awareness of prevention and early detection of skin cancer using moulage in a human patient simulation lab. Through the use of moulage-like lesions, simulated patients were evaluated and taught skin cancer prevention and early detection principles by baccalaureate nursing students. The average age of study participants (n = 104) was 26.50 years. The majority of responders were female. At the end of the lab, students' average responses to an evaluation based on program goals were very positive. Anecdotal comments affirmed positive student perceptions of their simulation experience. Data analyses indicated item means were consistently higher for upper-division students. The age and gender of students who participated in this study align with the NCI statistics on age and gender of the population with increased incidence of melanoma.

An in vitro human skin test for assessing sensitization potential.

PubMed

Ahmed, S S; Wang, X N; Fielding, M; Kerry, A; Dickinson, I; Munuswamy, R; Kimber, I; Dickinson, A M

2016-05-01

Sensitization to chemicals resulting in an allergy is an important health issue. The current gold-standard method for identification and characterization of skin-sensitizing chemicals was the mouse local lymph node assay (LLNA). However, for a number of reasons there has been an increasing imperative to develop alternative approaches to hazard identification that do not require the use of animals. Here we describe a human in-vitro skin explant test for identification of sensitization hazards and the assessment of relative skin sensitizing potency. This method measures histological damage in human skin as a readout of the immune response induced by the test material. Using this approach we have measured responses to 44 chemicals including skin sensitizers, pre/pro-haptens, respiratory sensitizers, non-sensitizing chemicals (including skin-irritants) and previously misclassified compounds. Based on comparisons with the LLNA, the skin explant test gave 95% specificity, 95% sensitivity, 95% concordance with a correlation coefficient of 0.9. The same specificity and sensitivity were achieved for comparison of results with published human sensitization data with a correlation coefficient of 0.91. The test also successfully identified nickel sulphate as a human skin sensitizer, which was misclassified as negative in the LLNA. In addition, sensitizers and non-sensitizers identified as positive or negative by the skin explant test have induced high/low T cell proliferation and IFNγ production, respectively. Collectively, the data suggests the human in-vitro skin explant test could provide the basis for a novel approach for characterization of the sensitizing activity as a first step in the risk assessment process. Copyright © 2015 John Wiley & Sons, Ltd.

Measuring hemoglobin amount and oxygen saturation of skin with advancing age

NASA Astrophysics Data System (ADS)

Watanabe, Shumpei; Yamamoto, Satoshi; Yamauchi, Midori; Tsumura, Norimichi; Ogawa-Ochiai, Keiko; Akiba, Tetsuo

2012-03-01

We measured the oxygen saturation of skin at various ages using our previously proposed method that can rapidly simulate skin spectral reflectance with high accuracy. Oxygen saturation is commonly measured by a pulse oximeter to evaluate oxygen delivery for monitoring the functions of heart and lungs at a specific time. On the other hand, oxygen saturation of skin is expected to assess peripheral conditions. Our previously proposed method, the optical path-length matrix method (OPLM), is based on a Monte Carlo for multi-layered media (MCML), but can simulate skin spectral reflectance 27,000 times faster than MCML. In this study, we implemented an iterative simulation of OPLM with a nonlinear optimization technique such that this method can also be used for estimating hemoglobin concentration and oxygen saturation from the measured skin spectral reflectance. In the experiments, the skin reflectance spectra of 72 outpatients aged between 20 and 86 years were measured by a spectrophotometer. Three points were measured for each subject: the forearm, the thenar eminence, and the intermediate phalanx. The result showed that the oxygen saturation of skin remained constant at each point as the age varied.

Transcriptome and ultrastructural changes in dystrophic Epidermolysis bullosa resemble skin aging

PubMed Central

Trost, Andrea; Weber, Manuela; Klausegger, Alfred; Gruber, Christina; Bruckner, Daniela; Reitsamer, Herbert A.; Bauer, Johann W.; Breitenbach, Michael

2015-01-01

The aging process of skin has been investigated recently with respect to mitochondrial function and oxidative stress. We have here observed striking phenotypic and clinical similarity between skin aging and recessive dystrophic Epidermolysis bullosa (RDEB), which is caused by recessive mutations in the gene coding for collagen VII, COL7A1. Ultrastructural changes, defects in wound healing, and inflammation markers are in part shared with aged skin. We have here compared the skin transcriptomes of young adults suffering from RDEB with that of sex‐ and age‐matched healthy probands. In parallel we have compared the skin transcriptome of healthy young adults with that of elderly healthy donors. Quite surprisingly, there was a large overlap of the two gene lists that concerned a limited number of functional protein families. Most prominent among the proteins found are a number of proteins of the cornified envelope or proteins mechanistically involved in cornification and other skin proteins. Further, the overlap list contains a large number of genes with a known role in inflammation. We are documenting some of the most prominent ultrastructural and protein changes by immunofluorescence analysis of skin sections from patients, old individuals, and healthy controls. PMID:26143532

Biorevitalizing effect of a novel facial serum containing apple stem cell extract, pro-collagen lipopeptide, creatine, and urea on skin aging signs.

PubMed

Sanz, Maria Teresa; Campos, Celia; Milani, Massimo; Foyaca, Monica; Lamy, Amandine; Kurdian, Karine; Trullas, Carles

2016-03-01

Epithelial regeneration in skin is achieved by the constant turnover and differentiation of keratinocytes. Epidermal and dermal stem cells compartments are fundamental for the continuous renewal of the skin. Adult stem cells are the unique source for skin tissue renewal. Plants have stem cells and plant derived stem cell extracts are now used in topical products for their potential anti-ageing and anti-wrinkle effects. A new dermocosmetic product containing apple stem cell extract, urea, creatine and palmitoyl tripeptide-38 (Ureadin Fusion Serum Lift Antiarrugas, ISDIN S.A), has been recently developed to target different aspects involved in skin aging. To assess in vitro the effects of this new serum on the metabolic functions of human senescent fibroblasts and in vivo the anti-aging effects by clinical and instrumental evaluation. We evaluated the effects of the serum on the mitochondrial ROS (reactive oxygen species) production in human senescent cultured fibroblasts measured at 0.1% and 1% using the Mitoread AntiOx mtROS method. In addition we evaluated the anti-ageing in vivo effect of this new serum applied on the face twice daily for 28 consecutive days and assessed by clinical and instrumental evaluation in 32 women with sensitive skin bearing wrinkles on crow's feet. The tested serum both at 0.1% and 1% induces a significant increase in 02 consumption, cellular ATP level and a reduction in extra-cellular lactate concentration. The product reduces also significantly the mitochondrial ROS production. The clinical study shows a relevant anti-wrinkle effect in 71% of the treated women with visible effects in 68% of the subjects as soon as 7 days of treatment. A significant increase in dermal density and skin elasticity was also observed. The use of this novel anti-aging serum demonstrated a significant improvement of aging skin signs with first visible results achieved after one week of use. The product seemed to optimize the metabolic functions in human

Effects of dimethylaminoethanol and compound amino acid on D-galactose induced skin aging model of rat.

PubMed

Liu, Su; Chen, Zhenyu; Cai, Xia; Sun, Ying; Zhao, Cailing; Liu, Fangjun; Liu, Dalie

2014-01-01

A lasting dream of human beings is to reverse or postpone aging. In this study, dimethylaminoethanol (DMAE) and compound amino acid (AA) in Mesotherapy were investigated for their potential antiaging effects on D-galactose induced aging skin. At 18 days after D-gal induction, each rat was treated with intradermal microinjection of saline, AA, 0.1% DMAE, 0.2% DMAE, 0.1% DMAE + AA, or 0.2% DMAE + AA, respectively. At 42 days after treatment, the skin wound was harvested and assayed. Measurement of epidermal and dermal thickness in 0.1% DMAE + AA and 0.2% DMAE + AA groups appeared significantly thicker than aging control rats. No differences were found in tissue water content among groups. Hydroxyproline in 0.1% DMAE + AA, 0.2% DMAE + AA, and sham control groups was much higher than all other groups. Collagen type I, type III, and MMP-1 expression was highly upregulated in both 0.1% DMAE + AA and 0.2% DMAE + AA groups compared with aging control. In contrast, TIMP-1 expression levels of various aging groups were significantly reduced when compared to sham control. Coinjection of DMAE and AA into target tissue has marked antiaging effects on D-galactose induced skin aging model of rat.

Effects of Dimethylaminoethanol and Compound Amino Acid on D-Galactose Induced Skin Aging Model of Rat

PubMed Central

Liu, Su; Chen, Zhenyu; Cai, Xia; Sun, Ying; Zhao, Cailing

2014-01-01

A lasting dream of human beings is to reverse or postpone aging. In this study, dimethylaminoethanol (DMAE) and compound amino acid (AA) in Mesotherapy were investigated for their potential antiaging effects on D-galactose induced aging skin. At 18 days after D-gal induction, each rat was treated with intradermal microinjection of saline, AA, 0.1% DMAE, 0.2% DMAE, 0.1% DMAE + AA, or 0.2% DMAE + AA, respectively. At 42 days after treatment, the skin wound was harvested and assayed. Measurement of epidermal and dermal thickness in 0.1% DMAE + AA and 0.2% DMAE + AA groups appeared significantly thicker than aging control rats. No differences were found in tissue water content among groups. Hydroxyproline in 0.1% DMAE + AA, 0.2% DMAE + AA, and sham control groups was much higher than all other groups. Collagen type I, type III, and MMP-1 expression was highly upregulated in both 0.1% DMAE + AA and 0.2% DMAE + AA groups compared with aging control. In contrast, TIMP-1 expression levels of various aging groups were significantly reduced when compared to sham control. Coinjection of DMAE and AA into target tissue has marked antiaging effects on D-galactose induced skin aging model of rat. PMID:25133239

Exosomes derived from human umbilical cord blood mesenchymal stem cells stimulates rejuvenation of human skin.

PubMed

Kim, Yoon-Jin; Yoo, Sae Mi; Park, Hwan Hee; Lim, Hye Jin; Kim, Yu-Lee; Lee, Seunghee; Seo, Kwang-Won; Kang, Kyung-Sun

2017-11-18

Human umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs) play an important role in cutaneous wound healing, and recent studies suggested that MSC-derived exosomes activate several signaling pathways, which are conducive in wound healing and cell growth. In this study, we investigated the roles of exosomes that are derived from USC-CM (USC-CM Exos) in cutaneous collagen synthesis and permeation. We found that USC-CM has various growth factors associated with skin rejuvenation. Our in vitro results showed that USC-CM Exos integrate in Human Dermal Fibroblasts (HDFs) and consequently promote cell migration and collagen synthesis of HDFs. Moreover, we evaluated skin permeation of USC-CM Exos by using human skin tissues. Results showed that Exo-Green labeled USC-CM Exos approached the outermost layer of the epidermis after 3 h and gradually approached the epidermis after 18 h. Moreover, increased expressions of Collagen I and Elastin were found after 3 days of treatment on human skin. The results showed that USC-CM Exos is absorbed into human skin, it promotes Collagen I and Elastin synthesis in the skin, which are essential to skin rejuvenation and shows the potential of USC-CM integration with the cosmetics or therapeutics. Copyright © 2017 Elsevier Inc. All rights reserved.

Rat epidermal keratinocyte organotypic culture (ROC) compared to human cadaver skin: the effect of skin permeation enhancers.

PubMed

Pappinen, Sari; Tikkinen, Sanna; Pasonen-Seppänen, Sanna; Murtomäki, Lasse; Suhonen, Marjukka; Urtti, Arto

2007-03-01

The objective of this study was to evaluate the response of the rat epidermal keratinocyte organotypic culture (ROC) to permeation enhancers, and to compare these responses to those in human cadaver skin. Different concentrations of two mixtures for enhancing permeation were investigated, sodium dodecyl sulfate:phenyl piperazine and methyl pyrrolidone:dodecyl pyridinium chloride, using skin impedance spectroscopy and two experimental compounds, the lipophilic corticosterone and the hydrophilic sucrose. The chemical irritation effects of the formulations were evaluated based on leakage of lactate dehydrogenase enzyme (LDH) and cellular morphological perturbation. This study provides evidence for direct correlations of permeation/permeation, impedance/impedance and permation/impedance between the culture model and human skin. The only exception was the enhancer induced permeation of sucrose which was 1-40-fold higher in ROC compared to human skin, reflecting the more disordered lipid organization in stratum corneum and consequently the greater number of polar pathways. LDH leakage and cellular morphology indicated that it was possible to differentiate between safe permeation enhancers from irritating agents. This is not only the first study to have compared the enhancer effects on a cultured skin model with human skin, but also it has demonstrated enhancer induced irritation using an artificial skin model.

Instrumentation for the measurement of autofluorescence in human skin

NASA Astrophysics Data System (ADS)

Graaff, Reindert; Meerwaldt, Robbert; Lutgers, Helen L.; Baptist, Rene; de Jong, Ed D.; Zijp, Jaap R.; Links, Thera P.; Smit, Andries J.; Rakhorst, Gerhard

2005-04-01

A setup to measure skin autofluorescence was developed to assess accumulation of advanced glycation endproducts (AGE) in patients noninvasively. The method applies direct blacklight tube illumination of the skin of the lower arm, and spectrometry. The setup displays skin autofluorescence (AF) as a ratio of mean intensities detected from the skin between 420-600 nm and 300-420 nm, respectively. In an early clinical application in 46 and control subjects matched for age and gender, AF was significantly increased in the patients (p = 0.015), and highly correlated with skin AGE's that were determined from skin biopsies in both groups. A large follow-up study on type 2 diabetes mellitus, ongoing since 2001 with more than 1000 subjects, aims to assess the value of the instrument in predicting chronic complications of diabetes. At baseline, a relation with age, glycemic status and with complications present was found. In a study in patients with end stage renal disease on dialysis AF was a strong and independent predictor of total and cardiovascular mortality. A commercial version of this AGE-reader is now under development and becomes available early 2005 (DiagnOptics B.V., Groningen, The Netherlands). One of the remaining questions, that will be answered by measuring so-called Exciation-Emission Matrices (EEM's) of the skin tissue in vivo, is whether a more selective choice of wavelengths is more strongly related to clinical characteristics. An experimental instrument to measure these EEM's was, therefore, developed as well. Clinical measurements are underway of EEM's in patient groups with diabetes mellitus and in healthy volunteers.

Skin aging parameters: A window to heart block.

PubMed

Roshdy, Hisham Samir; Soliman, Mohammad Hassan; El-Dosouky, Ibtesam Ibrahim; Ghonemy, Soheir

2018-01-01

Skin acts as a mirror to the internal state of the body. We tried to find the relation between skin aging parameters and the incidence of degenerative AV block. 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. 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. 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. © 2017 Wiley Periodicals, Inc.

Cutaneous human papillomaviruses persist on healthy skin.

PubMed

Hazard, Kristina; Karlsson, Anna; Andersson, Kristin; Ekberg, Henrik; Dillner, Joakim; Forslund, Ola

2007-01-01

Cutaneous human papillomaviruses (HPVs) are frequently found in healthy skin and have also been implicated in non-melanoma skin cancer. For genital HPV types, a persistent infection with one of the high-risk types is a prerequisite for the development of cervical cancer. However, there is only limited data on whether infections with cutaneous HPV types persist over time. Serial forehead swab samples collected from 63 volunteers (42 healthy individuals and 31 renal transplant recipients (RTRs)), sampled 6.3 years (range: 5.0-7.0 years) apart, were analyzed for HPV using general primer PCR, cloning, and sequencing. Among the healthy individuals, the prevalences of HPV were 69% (29/42) at enrolment and 71% (30/42) at follow-up. Among the individuals positive at baseline, 48% (14/29) had a persistent infection. Among the RTRs, 71% (15/21) were positive for HPV at enrolment and 90% (19/21) at follow-up. A persistent infection was detected in 33% (5/15). In total, HPV was detected in 44 of the samples collected at baseline and the same virus was found at follow-up in 43% (19/44). Persistence was not significantly associated with age, sex, immunosuppressive treatment, history of warts, or genus of HPV. We conclude that cutaneous HPV infections commonly persist over several years on healthy skin.

An anisotropic, hyperelastic model for skin: experimental measurements, finite element modelling and identification of parameters for human and murine skin.

PubMed

Groves, Rachel B; Coulman, Sion A; Birchall, James C; Evans, Sam L

2013-02-01

The mechanical characteristics of skin are extremely complex and have not been satisfactorily simulated by conventional engineering models. The ability to predict human skin behaviour and to evaluate changes in the mechanical properties of the tissue would inform engineering design and would prove valuable in a diversity of disciplines, for example the pharmaceutical and cosmetic industries, which currently rely upon experiments performed in animal models. The aim of this study was to develop a predictive anisotropic, hyperelastic constitutive model of human skin and to validate this model using laboratory data. As a corollary, the mechanical characteristics of human and murine skin have been compared. A novel experimental design, using tensile tests on circular skin specimens, and an optimisation procedure were adopted for laboratory experiments to identify the material parameters of the tissue. Uniaxial tensile tests were performed along three load axes on excised murine and human skin samples, using a single set of material parameters for each skin sample. A finite element model was developed using the transversely isotropic, hyperelastic constitutive model of Weiss et al. (1996) and was embedded within a Veronda-Westmann isotropic material matrix, using three fibre families to create anisotropic behaviour. The model was able to represent the nonlinear, anisotropic behaviour of the skin well. Additionally, examination of the optimal material coefficients and the experimental data permitted quantification of the mechanical differences between human and murine skin. Differences between the skin types, most notably the extension of the skin at low load, have highlighted some of the limitations of murine skin as a biomechanical model of the human tissue. The development of accurate, predictive computational models of human tissue, such as skin, to reduce, refine or replace animal models and to inform developments in the medical, engineering and cosmetic fields, is a

Next generation human skin constructs as advanced tools for drug development.

PubMed

Abaci, H E; Guo, Zongyou; Doucet, Yanne; Jacków, Joanna; Christiano, Angela

2017-11-01

Many diseases, as well as side effects of drugs, manifest themselves through skin symptoms. Skin is a complex tissue that hosts various specialized cell types and performs many roles including physical barrier, immune and sensory functions. Therefore, modeling skin in vitro presents technical challenges for tissue engineering. Since the first attempts at engineering human epidermis in 1970s, there has been a growing interest in generating full-thickness skin constructs mimicking physiological functions by incorporating various skin components, such as vasculature and melanocytes for pigmentation. Development of biomimetic in vitro human skin models with these physiological functions provides a new tool for drug discovery, disease modeling, regenerative medicine and basic research for skin biology. This goal, however, has long been delayed by the limited availability of different cell types, the challenges in establishing co-culture conditions, and the ability to recapitulate the 3D anatomy of the skin. Recent breakthroughs in induced pluripotent stem cell (iPSC) technology and microfabrication techniques such as 3D-printing have allowed for building more reliable and complex in vitro skin models for pharmaceutical screening. In this review, we focus on the current developments and prevailing challenges in generating skin constructs with vasculature, skin appendages such as hair follicles, pigmentation, immune response, innervation, and hypodermis. Furthermore, we discuss the promising advances that iPSC technology offers in order to generate in vitro models of genetic skin diseases, such as epidermolysis bullosa and psoriasis. We also discuss how future integration of the next generation human skin constructs onto microfluidic platforms along with other tissues could revolutionize the early stages of drug development by creating reliable evaluation of patient-specific effects of pharmaceutical agents. Impact statement Skin is a complex tissue that hosts various

Signatures of human skin in the millimetre wave band (80-100) GHz

NASA Astrophysics Data System (ADS)

Owda, Amani Y.; Rezgui, Nacer-Ddine; Salmon, Neil A.

2017-10-01

With the performance of millimeter wave security screening imagers improving (reduced speckle, greater sensitivity, and better spatial resolution) attention is turning to identification of anomalies which appear on the human body. Key to this identification is the understanding of how the emissive and reflective properties vary over the human body and between different categories of people, defined by age and gender for example. As the interaction of millimetre waves with the human body is only a fraction of a millimetre into the skin, precise measurement of the emission and reflection of this radiation will allow comparisons with the norm for that region of the body and person category. On an automated basis at security screening portals, this will increase detection probabilities and reduce false alarm rates, ensuring high throughputs at entrances to future airport departure lounges and transport networks. A technique to measure the human skin emissivity in vivo over the frequency band 80 GHz to 100 GHz is described. The emissivities of the skin of a sample of 60 healthy participants (36 males and 24 females) measured using a 90 GHz calibrated radiometer was found to range from 0.17+/-0.002 to 0.68+/-0.002. The radiometric measurements were made at four locations on the arm, namely: palm of hand, back of hand, dorsal surface of the forearm, and volar side of the forearm, where the water content and the skin thickness are known to be different. These measurements show significant variation in emissivity from person to person and, more importantly, significant variation at different locations on the arms of individuals. Males were found to have an emissivity 0.03 higher than those of females. The emissivity of the back of the hand, where the skin is thinner and the blood vessels are closer to the skin surface, was found to be lower by 0.0681 than the emissivity of the palm of the hand, where the skin is thicker. The measurements also show that the emissivity of the

Colour homogeneity and visual perception of age, health and attractiveness of male facial skin.

PubMed

Fink, B; Matts, P J; D'Emiliano, D; Bunse, L; Weege, B; Röder, S

2012-12-01

Visible facial skin condition in females is known to affect perception of age, health and attractiveness. Skin colour distribution in shape- and topography-standardized female faces, driven by localized melanin and haemoglobin, can account for up to twenty years of apparent age perception. Although this is corroborated by an ability to discern female age even in isolated, non-contextual skin images, a similar effect in the perception of male skin is yet to be demonstrated. To investigate the effect of skin colour homogeneity and chromophore distribution on the visual perception of age, health and attractiveness of male facial skin. Cropped images from the cheeks of facial images of 160 Caucasian British men aged 10-70 years were blind-rated for age, health and attractiveness by a total of 308 participants. In addition, the homogeneity of skin images and corresponding eumelanin/oxyhaemoglobin concentration maps were analysed objectively using Haralick's image segmentation algorithm. Isolated skin images taken from the cheeks of younger males were judged as healthier and more attractive. Perception of age, health and attractiveness was strongly related to melanin and haemoglobin distribution, whereby more even distributions led to perception of younger age and greater health and attractiveness. The evenness of melanized features was a stronger cue for age perception, whereas haemoglobin distribution was associated more strongly with health and attractiveness perception. Male skin colour homogeneity, driven by melanin and haemoglobin distribution, influences perception of age, health and attractiveness. © 2011 The Authors. Journal of the European Academy of Dermatology and Venereology © 2011 European Academy of Dermatology and Venereology.

The impact of cellular senescence in skin ageing: A notion of mosaic and therapeutic strategies.

PubMed

Toutfaire, Marie; Bauwens, Emilie; Debacq-Chainiaux, Florence

2017-10-15

Cellular senescence is now recognized as one of the nine hallmarks of ageing. Recent data show the involvement of senescent cells in tissue ageing and some age-related diseases. Skin represents an ideal model for the study of ageing. Indeed, skin ageing varies between individuals depending on their chronological age but also on their exposure to various exogenous factors (mainly ultraviolet rays). If senescence traits can be detected with ageing in the skin, the senescent phenotype varies among the various skin cell types. Moreover, the origin of cellular senescence in the skin is still unknown, and multiple origins are possible. This reflects the mosaic of skin ageing. Senescent cells can interfere with their microenvironment, either via the direct secretion of factors (the senescence-associated secretory phenotype) or via other methods of communication, such as extracellular vesicles. Knowledge regarding the impact of cellular senescence on skin ageing could be integrated into dermatology research, especially to limit the appearance of senescent cells after photo(chemo)therapy or in age-related skin diseases. Therapeutic approaches include the clearance of senescent cells via the use of senolytics or via the cooperation with the immune system. Copyright © 2017 Elsevier Inc. All rights reserved.

Setup for investigating gold nanoparticle penetration through reconstructed skin and comparison to published human skin data

NASA Astrophysics Data System (ADS)

Labouta, Hagar I.; Thude, Sibylle; Schneider, Marc

2013-06-01

Owing to the limited source of human skin (HS) and the ethical restrictions of using animals in experiments, in vitro skin equivalents are a possible alternative for conducting particle penetration experiments. The conditions for conducting penetration experiments with model particles, 15-nm gold nanoparticles (AuNP), through nonsealed skin equivalents are described for the first time. These conditions include experimental setup, sterility conditions, effective applied dose determination, skin sectioning, and skin integrity check. Penetration at different exposure times (two and 24 h) and after tissue fixation (fixed versus unfixed skin) are examined to establish a benchmark in comparison to HS in an attempt to get similar results to HS experiments presented earlier. Multiphoton microscopy is used to detect gold luminescence in skin sections. λex=800 nm is used for excitation of AuNP and skin samples, allowing us to determine a relative index for particle penetration. Despite the observed overpredictability of penetration into skin equivalents, they could serve as a first fast screen for testing the behavior of nanoparticles and extrapolate their penetration behavior into HS. Further investigations are required to test a wide range of particles of different physicochemical properties to validate the skin equivalent-human skin particle penetration relationship.

Nanoethosomal formulation of gammaoryzanol for skin-aging protection and wrinkle improvement: a histopathological study.

PubMed

Heydari, Saman; Ghanbarzadeh, Saeed; Anoush, Behzad; Ranjkesh, Mohammadreza; Javadzadeh, Yousef; Kouhsoltani, Maryam; Hamishehkar, Hamed

2017-07-01

Free radical scavengers and antioxidants, with the main focus on enhanced targeting to the skin layers, can provide protection against skin ageing. The aim of the present study was to prepare nanoethosomal formulation of gammaoryzanol (GO), a water insoluble antioxidant, for its dermal delivery to prevent skin aging. Nanoethosomal formulation was prepared by a modified ethanol injection method and characterized by using laser light scattering, scanning electronic microscope (SEM) and X-ray diffraction (XRD) techniques. The effects of formulation parameters on nanoparticle size, encapsulation efficiency percent (EE%) and loading capacity percent (LC%) were investigated. Antioxidant activity of GO-loaded formulation was investigated in vitro using normal African green monkey kidney fibroblast cells (Vero). The effect of control and GO-loaded nanoethosomal formulation on superoxide dismutase (SOD) and malondialdehyde (MDA) content of rat skin was also probed. Furthermore, the effect of GO-loaded nanoethosomes on skin wrinkle improvement was studied by dermoscopic and histological examination on healthy humans and UV-irradiated rats, respectively. The optimized nanoethosomal formulation showed promising characteristics including narrow size distribution 0.17 ± 0.02, mean diameter of 98.9 ± 0.05 nm, EE% of 97.12 ± 3.62%, LC% of 13.87 ± 1.36% and zeta potential value of -15.1 ± 0.9 mV. The XRD results confirmed uniform drug dispersion in the nanoethosomes structure. In vitro and in vivo antioxidant studies confirmed the superior antioxidant effect of GO-loaded nanoethosomal formulation compared with control groups (blank nanoethosomes and GO suspension). Nanoethosomes was a promising carrier for dermal delivery of GO and consequently had superior anti-aging effect.

Diverse human skin fungal communities in children converge in adulthood

PubMed Central

Jo, Jay-Hyun; Deming, Clayton; Kennedy, Elizabeth A.; Conlan, Sean; Polley, Eric C.; Ng, Weng-lan; Segre, Julia A.; Kong, Heidi H.

2017-01-01

Understanding the skin mycobiome (fungal communities) is important because both commensal and pathogenic fungi can drive cutaneous disease depending on host status and body sites, including the scalp, feet, and groin. Interestingly, age may also affect skin fungal infections as certain dermatophytoses (i.e. tinea capitis) are more frequent in children than adults. We previously described the skin mycobiomes in healthy adults, showing lipophilic fungi Malassezia predominate in most skin sites. Since children have less sebaceous skin before puberty, we compared the fungal communities of primary clinical samples from healthy children and adults, based on sequencing of a fungal phylogenetic marker. While Malassezia predominated on trunk, head and arm skin of adults (age 20s–30s), children (age <14) had more diverse fungal communities, for example, Eurotiomycetes which includes common dermatophytes. Species-level classification showed M. globosa predominated in children. Collectively, our findings indicate that prepubertal skin is colonized by diverse fungi, whereas adult skin is predominantly obligatory lipophilic Malassezia, suggesting that fungal communities on skin profoundly shift during puberty. Mycobiome shifts during puberty are likely due to alterations in sebaceous gland activation and sebum composition. This study provides a foundational framework for studies investigating interactions between fungi, skin, and pediatric dermatophytosis. PMID:27476723

Diverse Human Skin Fungal Communities in Children Converge in Adulthood.

PubMed

Jo, Jay-Hyun; Deming, Clay; Kennedy, Elizabeth A; Conlan, Sean; Polley, Eric C; Ng, Weng-Ian; Segre, Julia A; Kong, Heidi H

2016-12-01

Understanding the skin mycobiome (fungal communities) is important because both commensal and pathogenic fungi can drive cutaneous disease depending on host status and body sites, including the scalp, feet, and groin. Interestingly, age may also affect skin fungal infections as certain dermatophytoses (i.e., tinea capitis) are more frequent in children than adults. We previously described the skin mycobiomes in healthy adults, showing lipophilic fungi Malassezia predominate in most skin sites. Because children have less sebaceous skin before puberty, we compared the fungal communities of primary clinical samples from healthy children and adults, based on sequencing of a fungal phylogenetic marker. Although Malassezia predominated on the trunk, head, and arm skin of adults (age 18-39), children (age < 14) had more diverse fungal communities, for example, Eurotiomycetes, which includes common dermatophytes. Species-level classification showed that Malassezia globosa predominated in children. Collectively, our findings indicate that prepubertal skin is colonized by diverse fungi, whereas adult skin is predominantly obligatory lipophilic Malassezia, suggesting that fungal communities on skin profoundly shift during puberty. Mycobiome shifts during puberty are likely due to alterations in sebaceous gland activation and sebum composition. This study provides a foundational framework for studies investigating interactions between fungi, skin, and pediatric dermatophytosis. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Comparison of human skin irritation patch test data with in vitro skin irritation assays and animal data.

PubMed

Jírová, Dagmar; Basketter, David; Liebsch, Manfred; Bendová, Hana; Kejlová, Kristina; Marriott, Marie; Kandárová, Helena

2010-02-01

Efforts to replace the rabbit skin irritation test have been underway for many years, encouraged by the EU Cosmetics Directive and REACH. Recently various in vitro tests have been developed, evaluated and validated. A key difficulty in confirming the validity of in vitro methods is that animal data are scarce and of limited utility for prediction of human effects, which adversely impacts their acceptance. This study examines whether in vivo or in vitro data most accurately predicted human effects. Using the 4-hr human patch test (HPT) we examined a number of chemicals whose EU classification of skin irritancy is known to be borderline, or where in vitro methods provided conflicting results. Of the 16 chemicals classified as irritants in the rabbit, only five substances were found to be significantly irritating to human skin. Concordance of the rabbit test with the 4-hr HPT was only 56%, whereas concordance of human epidermis models with human data was 76% (EpiDerm) and 70% (EPISKIN). The results confirm observations that rabbits overpredict skin effects in humans. Therefore, when validating in vitro methods, all available information, including human data, should be taken into account before making conclusions about their predictive capacity.

Impact of chemical peeling combined with negative pressure on human skin.

PubMed

Kim, S J; Kang, I J; Shin, M K; Jeong, K H; Baek, J H; Koh, J S; Lee, S J

2016-10-01

In vivo changes in skin barrier function after chemical peeling with alpha hydroxyacids (AHAs) have been previously reported. However, the additional effects of physical treatment with chemical agents on skin barrier function have not been adequately studied. This study measured the degree of acute skin damage and the time required for skin barrier repair using non-invasive bioengineering methods in vivo with human skin to investigate the additional effect of a 4% AHA chemical jet accelerated at supersonic velocities. Thirteen female subjects (average age: 29.54 ± 4.86 years) participated in this study. The faces of the subjects were divided into half according to the block randomization design and were then assigned to receive AHA peeling alone or AHA peeling combined with pneumatic pressure on each side of the face. Transepidermal water loss (TEWL), skin colour and skin blood flow were evaluated at baseline and at 30 min, 2, 5 and 7 days after treatment. The TEWL and skin blood flow were significantly increased after 30 min in chemodermabrasion compared with chemical peeling alone (P < 0.05). The TEWL and skin blood flow recovered to baseline after 2 days, and TEWL was significantly decreased at 7 days compared with chemical peeling alone (P < 0.05). Chemodermabrasion can temporarily impair skin barriers, but it is estimated that it can enhance the skin barrier function after 7 days compared to the use of a chemical agent alone. In addition, chemodermabrasion has a more effective impact in the dermis and relatively preserves the skin barrier. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

The Nrf2-inducers tanshinone I and dihydrotanshinone protect human skin cells and reconstructed human skin against solar simulated UV☆

PubMed Central

Tao, Shasha; Justiniano, Rebecca; Zhang, Donna D.; Wondrak, Georg T.

2013-01-01

Exposure to solar ultraviolet (UV) radiation is a causative factor in skin photocarcinogenesis and photoaging, and an urgent need exists for improved strategies for skin photoprotection. The redox-sensitive transcription factor Nrf2 (nuclear factor-E2-related factor 2), a master regulator of the cellular antioxidant defense against environmental electrophilic insult, has recently emerged as an important determinant of cutaneous damage from solar UV, and the concept of pharmacological activation of Nrf2 has attracted considerable attention as a novel approach to skin photoprotection. In this study, we examined feasibility of using tanshinones, a novel class of phenanthrenequinone-based cytoprotective Nrf2 inducers derived from the medicinal plant Salvia miltiorrhiza, for protection of cultured human skin cells and reconstructed human skin against solar simulated UV. Using a dual luciferase reporter assay in human Hs27 dermal fibroblasts pronounced transcriptional activation of Nrf2 by four major tanshinones [tanshinone I (T-I), dihydrotanshinone (DHT), tanshinone IIA (T-II-A) and cryptotanshinone (CT)] was detected. In fibroblasts, the more potent tanshinones T-I and DHT caused a significant increase in Nrf2 protein half-life via blockage of ubiquitination, ultimately resulting in upregulated expression of cytoprotective Nrf2 target genes (GCLC, NQO1) with the elevation of cellular glutathione levels. Similar tanshinone-induced changes were also observed in HaCaT keratinocytes. T-I and DHT pretreatment caused significant suppression of skin cell death induced by solar simulated UV and riboflavin-sensitized UVA. Moreover, feasibility of tanshinone-based cutaneous photoprotection was tested employing a human skin reconstruct exposed to solar simulated UV (80 mJ/cm2 UVB; 1.53 J/cm2 UVA). The occurrence of markers of epidermal solar insult (cleaved procaspase 3, pycnotic nuclei, eosinophilic cytoplasm, acellular cavities) was significantly attenuated in DHT

QSAR models of human data can enrich or replace LLNA testing for human skin sensitization

PubMed Central

Alves, Vinicius M.; Capuzzi, Stephen J.; Muratov, Eugene; Braga, Rodolpho C.; Thornton, Thomas; Fourches, Denis; Strickland, Judy; Kleinstreuer, Nicole; Andrade, Carolina H.; Tropsha, Alexander

2016-01-01

Skin sensitization is a major environmental and occupational health hazard. Although many chemicals have been evaluated in humans, there have been no efforts to model these data to date. We have compiled, curated, analyzed, and compared the available human and LLNA data. Using these data, we have developed reliable computational models and applied them for virtual screening of chemical libraries to identify putative skin sensitizers. The overall concordance between murine LLNA and human skin sensitization responses for a set of 135 unique chemicals was low (R = 28-43%), although several chemical classes had high concordance. We have succeeded to develop predictive QSAR models of all available human data with the external correct classification rate of 71%. A consensus model integrating concordant QSAR predictions and LLNA results afforded a higher CCR of 82% but at the expense of the reduced external dataset coverage (52%). We used the developed QSAR models for virtual screening of CosIng database and identified 1061 putative skin sensitizers; for seventeen of these compounds, we found published evidence of their skin sensitization effects. Models reported herein provide more accurate alternative to LLNA testing for human skin sensitization assessment across diverse chemical data. In addition, they can also be used to guide the structural optimization of toxic compounds to reduce their skin sensitization potential. PMID:28630595

Confocal Raman study of aging process in diabetes mellitus human voluntaries

NASA Astrophysics Data System (ADS)

Pereira, Liliane; Téllez Soto, Claudio Alberto; dos Santos, Laurita; Ali, Syed Mohammed; Fávero, Priscila Pereira; Martin, Airton A.

2015-06-01

Accumulation of AGEs [Advanced Glycation End - products] occurs slowly during the human aging process. However, its formation is accelerated in the presence of diabetes mellitus. In this paper, we perform a noninvasive analysis of glycation effect on human skin by in vivo confocal Raman spectroscopy. This technique uses a laser of 785 nm as excitation source and, by the inelastic scattering of light, it is possible to obtain information about the biochemical composition of the skin. Our aim in this work was to characterize the aging process resulting from the glycation process in a group of 10 Health Elderly Women (HEW) and 10 Diabetic Elderly Women (DEW). The Raman data were collected from the dermis at a depth of 70-130 microns. Through the theory of functional density (DFT) the bands positions of hydroxyproline, proline and AGEs (pentosidine and glucosepane) were calculated by using Gaussian 0.9 software. A molecular interpretation of changes in type I collagen was performed by the changes in the vibrational modes of the proline (P) and hydroxyproline (HP). The data analysis shows that the aging effects caused by glycation of proteins degrades type I collagen differently and leads to accelerated aging process.

Comparative study of carotenoids, catalase and radical formation in human and animal skin.

PubMed

Haag, S F; Bechtel, A; Darvin, M E; Klein, F; Groth, N; Schäfer-Korting, M; Bittl, R; Lademann, J; Sterry, W; Meinke, M C

2010-01-01

Animal skin is widely used in dermatological free radical research. Porcine ear skin is a well-studied substitute for human skin. The use of bovine udder skin is rare but its high carotenoid content makes it particularly appropriate for studying the redox state of the skin. Yet, information on the suitability of animal skin for the study of external hazard effects on the redox state of human skin has been lacking. In this study, we investigated the activity of the antioxidant enzyme catalase and the carotenoid content defining the redox status as well as UV-induced radical formation of human, porcine ear and bovine udder skin ex vivo. In human skin only low levels of radical formation were detected following UV irradiation, whereas bovine skin contains the highest amount of carotenoids but the lowest amount of catalase. Porcine ear skin does not exhibit a carotenoid signal but its catalase activity is close to human skin. Therefore, radical formation can neither be correlated to the amount of catalase nor to the amount of carotenoids in the skin. All skin types can be used for electron paramagnetic resonance-based detection of radicals, but porcine skin was found to be the most suitable type. Copyright 2010 S. Karger AG, Basel.

Diffuse colonies of human skin fibroblasts in relation to cellular senescence and proliferation.

PubMed

Zorin, Vadim; Zorina, Alla; Smetanina, Nadezhda; Kopnin, Pavel; Ozerov, Ivan V; Leonov, Sergey; Isaev, Artur; Klokov, Dmitry; Osipov, Andreyan N

2017-05-16

Development of personalized skin treatment in medicine and skin care may benefit from simple and accurate evaluation of the fraction of senescent skin fibroblasts that lost their proliferative capacity. We examined whether enriched analysis of colonies formed by primary human skin fibroblasts, a simple and widely available cellular assay, could reveal correlations with the fraction of senescent cells in heterogenic cell population. We measured fractions of senescence associated β-galactosidase (SA-βgal) positive cells in either mass cultures or colonies of various morphological types (dense, mixed and diffuse) formed by skin fibroblasts from 10 human donors. Although the donors were chosen to be within the same age group (33-54 years), the colony forming efficiency of their fibroblasts (ECO-f) and the percentage of dense, mixed and diffuse colonies varied greatly among the donors. We showed, for the first time, that the SA-βgal positive fraction was the largest in diffuse colonies, confirming that they originated from cells with the least proliferative capacity. The percentage of diffuse colonies was also found to correlate with the SA-βgal positive cells in mass culture. Using Ki67 as a cell proliferation marker, we further demonstrated a strong inverse correlation (r=-0.85, p=0.02) between the percentage of diffuse colonies and the fraction of Ki67+ cells. Moreover, a significant inverse correlation (r=-0.94, p=0.0001) between the percentage of diffuse colonies and ECO-f was found. Our data indicate that quantification of a fraction of diffuse colonies may provide a simple and useful method to evaluate the extent of cellular senescence in human skin fibroblasts.

Generation of Genetically Modified Organotypic Skin Cultures Using Devitalized Human Dermis.

PubMed

Li, Jingting; Sen, George L

2015-12-14

Organotypic cultures allow the reconstitution of a 3D environment critical for cell-cell contact and cell-matrix interactions which mimics the function and physiology of their in vivo tissue counterparts. This is exemplified by organotypic skin cultures which faithfully recapitulates the epidermal differentiation and stratification program. Primary human epidermal keratinocytes are genetically manipulable through retroviruses where genes can be easily overexpressed or knocked down. These genetically modified keratinocytes can then be used to regenerate human epidermis in organotypic skin cultures providing a powerful model to study genetic pathways impacting epidermal growth, differentiation, and disease progression. The protocols presented here describe methods to prepare devitalized human dermis as well as to genetically manipulate primary human keratinocytes in order to generate organotypic skin cultures. Regenerated human skin can be used in downstream applications such as gene expression profiling, immunostaining, and chromatin immunoprecipitations followed by high throughput sequencing. Thus, generation of these genetically modified organotypic skin cultures will allow the determination of genes that are critical for maintaining skin homeostasis.

Prediction of Human Pharmacokinetic Profile After Transdermal Drug Application Using Excised Human Skin.

PubMed

Yamamoto, Syunsuke; Karashima, Masatoshi; Arai, Yuta; Tohyama, Kimio; Amano, Nobuyuki

2017-09-01

Although several mathematical models have been reported for the estimation of human plasma concentration profiles of drug substances after dermal application, the successful cases that can predict human pharmacokinetic profiles are limited. Therefore, the aim of this study is to investigate the prediction of human plasma concentrations after dermal application using in vitro permeation parameters obtained from excised human skin. The in vitro skin permeability of 7 marketed drug products was evaluated. The plasma concentration-time profiles of the drug substances in humans after their dermal application were simulated using compartment models and the clinical pharmacokinetic parameters. The transdermal process was simulated using the in vitro skin permeation rate and lag time assuming a zero-order absorption. These simulated plasma concentration profiles were compared with the clinical data. The result revealed that the steady-state plasma concentration of diclofenac and the maximum concentrations of nicotine, bisoprolol, rivastigmine, and lidocaine after topical application were within 2-fold of the clinical data. Furthermore, the simulated concentration profiles of bisoprolol, nicotine, and rivastigmine reproduced the decrease in absorption due to drug depletion from the formulation. In conclusion, this simple compartment model using in vitro human skin permeation parameters as zero-order absorption predicted the human plasma concentrations accurately. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Effect of botanicals on inflammation and skin aging: analyzing the evidence.

PubMed

Suggs, Amanda; Oyetakin-White, Patricia; Baron, Elma D

2014-01-01

The skin and its immune system manifest a decline in physiologic function as it undergoes aging. External insults such as ultraviolet light exposure cause inflammation, which may enhance skin aging even further leading to cancer and signs of photoaging. There is a potential role for botanicals as an adjunct modality in the prevention of skin aging. Numerous over-the-counter anti-aging products are commercially available, many of which boast unverified claims to reduce stress, inflammation and correct signs of aging. In this article we reviewed the scientific literature for data on frequently published "anti-inflammaging" additives such as vitamins A, C and E and green tea. We also analyzed the evidence available on five promising ingredients commonly found in anti-aging products, namely, argan oil, rosemary, pomegranate, Coenzyme Q10, and Coffeeberry. Though there may be an increasing amount of scientific data on a few of these novel botanicals, in general, there remains a lack of clinical data to support the anti-aging claims made.

Ultrasonic Stimulation of Mouse Skin Reverses the Healing Delays in Diabetes and Aging by Activation of Rac1.

PubMed

Roper, James A; Williamson, Rosalind C; Bally, Blandine; Cowell, Christopher A M; Brooks, Rebecca; Stephens, Phil; Harrison, Andrew J; Bass, Mark D

2015-11-01

Chronic skin-healing defects are one of the leading challenges to lifelong well-being, affecting 2-5% of populations. Chronic wound formation is linked to age and diabetes and frequently leads to major limb amputation. Here we identify a strategy to reverse fibroblast senescence and improve healing rates. In healthy skin, fibronectin activates Rac1 in fibroblasts, causing migration into the wound bed, and driving wound contraction. We discover that mechanical stimulation of the skin with ultrasound can overturn healing defects by activating a calcium/CamKinaseII/Tiam1/Rac1 pathway that substitutes for fibronectin-dependent signaling and promotes fibroblast migration. Treatment of diabetic and aged mice recruits fibroblasts to the wound bed and reduces healing times by 30%, restoring healing rates to those observed in young, healthy animals. Ultrasound treatment is equally effective in rescuing the healing defects of animals lacking fibronectin receptors, and can be blocked by pharmacological inhibition of the CamKinaseII pathway. Finally, we discover that the migration defects of fibroblasts from human venous leg ulcer patients can be reversed by ultrasound, demonstrating that the approach is applicable to human chronic samples. By demonstrating that this alternative Rac1 pathway can substitute for that normally operating in the skin, we identify future opportunities for management of chronic wounds.

A multivariable model for predicting the frictional behaviour and hydration of the human skin.

PubMed

Veijgen, N K; van der Heide, E; Masen, M A

2013-08-01

The frictional characteristics of skin-object interactions are important when handling objects, in the assessment of perception and comfort of products and materials and in the origins and prevention of skin injuries. In this study, based on statistical methods, a quantitative model is developed that describes the friction behaviour of human skin as a function of the subject characteristics, contact conditions, the properties of the counter material as well as environmental conditions. Although the frictional behaviour of human skin is a multivariable problem, in literature the variables that are associated with skin friction have been studied using univariable methods. In this work, multivariable models for the static and dynamic coefficients of friction as well as for the hydration of the skin are presented. A total of 634 skin-friction measurements were performed using a recently developed tribometer. Using a statistical analysis, previously defined potential influential variables were linked to the static and dynamic coefficient of friction and to the hydration of the skin, resulting in three predictive quantitative models that descibe the friction behaviour and the hydration of human skin respectively. Increased dynamic coefficients of friction were obtained from older subjects, on the index finger, with materials with a higher surface energy at higher room temperatures, whereas lower dynamic coefficients of friction were obtained at lower skin temperatures, on the temple with rougher contact materials. The static coefficient of friction increased with higher skin hydration, increasing age, on the index finger, with materials with a higher surface energy and at higher ambient temperatures. The hydration of the skin was associated with the skin temperature, anatomical location, presence of hair on the skin and the relative air humidity. Predictive models have been derived for the static and dynamic coefficient of friction using a multivariable approach. These

Menopause increases the iron storage protein ferritin in skin.

PubMed

Pelle, Edward; Jian, Jinlong; Zhang, Qi; Muizzuddin, Neelam; Yang, Qing; Dai, Jisen; Maes, Daniel; Pernodet, Nadine; Yarosh, Daniel B; Frenkel, Krystyna; Huang, Xi

2013-01-01

Menstruation and desquamation are important routes for humans to excrete iron. Because menstruation is no longer available in postmenopausal women, in the present study, we examined whether iron accumulates more in postmenopausal skin than in premenopausal skin. Skin biopsy samples were obtained from six pre- and six postmenopausal Caucasian women. Iron levels in the form of ferritin were 42% higher, but vascular endothelial growth factor and total antioxidant capacity were 45% and 34% lower in postmenopausal skin (58.8 ± 1.3 years old) than in premenopausal skin (41.6 ± 1.7 years old), respectively. Moreover, in vitro cultured normal human epidermal keratinocytes had surprisingly high levels of ferritin when compared to immortalized human breast epithelial MCF-10A cells or human liver HepG2 cancer cells. Our results indicate that skin is a cellular repository of iron and that menopause increases iron in skin and, thus, may contribute to the manifestation of accelerated skin aging and photo aging after menopause.

Transplanting Human Skin Grafts onto Nude Mice to Model Skin Scars.

PubMed

Ding, Jie; Tredget, Edward E

2017-01-01

Hypertrophic scar (HTS) is a common outcome of deep dermal wound healing mainly followed mechanical, chemical, and thermal injuries in the skin. Because of the lack of the most effective prevention and treatment, it is particularly important to establish an ideal dermal animal model for improving the understanding of the pathogenesis and exploring therapeutic approaches of HTS. Compared to other dermal fibrotic animal models in rabbits, red Duroc pigs, guinea pigs, rats, and mice, the approach that uses normal human split-thickness skin grafted onto nude or other immunodeficient mice which develop scars that resemble human HTS offers the advantages of lower cost, easier manipulation, and shorter research period. In this chapter, we will introduce the detailed procedures to create the ideal dermal fibrotic mouse model.

Raman spectroscopic analysis of the increase of the carotenoid antioxidant concentration in human skin after a 1-week diet with ecological eggs

NASA Astrophysics Data System (ADS)

Hesterberg, Karoline; Lademann, Jürgen; Patzelt, Alexa; Sterry, Wolfram; Darvin, Maxim E.

2009-03-01

Skin aging is mainly caused by the destructive action of free radicals, produced by the UV light of the sun. The human skin has developed a protection system against these highly reactive molecules in the form of the antioxidative potential. Carotenoids are one of the main components of the antioxidants of the human skin. From former studies, it is known that skin aging is reduced in individuals with high levels of carotenoids. Because most of the antioxidants cannot be produced by the human organism, they must be up taken by nutrition. Using noninvasive Raman spectroscopic measurements it is demonstrated that not only fruits and vegetables but also eggs contain high concentrations of antioxidants including carotenoids, which are even doubled in the case of ecological eggs. After a 1-week diet with ecological eggs performed by six volunteers, it is found that the concentration of the carotenoids in the skin of the volunteers increased by approx. 20%. Our study does not intend to recommend exorbitant egg consumption, as eggs also contain harmful cholesterol. But in the case of egg consumption, ecological eggs from hens kept on pasture should be preferred to also receive a benefit for the skin.

Multivariate models for prediction of human skin sensitization hazard.

PubMed

Strickland, Judy; Zang, Qingda; Paris, Michael; Lehmann, David M; Allen, David; Choksi, Neepa; Matheson, Joanna; Jacobs, Abigail; Casey, Warren; Kleinstreuer, Nicole

2017-03-01

One of the Interagency Coordinating Committee on the Validation of Alternative Method's (ICCVAM) top priorities is the development and evaluation of non-animal approaches to identify potential skin sensitizers. The complexity of biological events necessary to produce skin sensitization suggests that no single alternative method will replace the currently accepted animal tests. ICCVAM is evaluating an integrated approach to testing and assessment based on the adverse outcome pathway for skin sensitization that uses machine learning approaches to predict human skin sensitization hazard. We combined data from three in chemico or in vitro assays - the direct peptide reactivity assay (DPRA), human cell line activation test (h-CLAT) and KeratinoSens™ assay - six physicochemical properties and an in silico read-across prediction of skin sensitization hazard into 12 variable groups. The variable groups were evaluated using two machine learning approaches, logistic regression and support vector machine, to predict human skin sensitization hazard. Models were trained on 72 substances and tested on an external set of 24 substances. The six models (three logistic regression and three support vector machine) with the highest accuracy (92%) used: (1) DPRA, h-CLAT and read-across; (2) DPRA, h-CLAT, read-across and KeratinoSens; or (3) DPRA, h-CLAT, read-across, KeratinoSens and log P. The models performed better at predicting human skin sensitization hazard than the murine local lymph node assay (accuracy 88%), any of the alternative methods alone (accuracy 63-79%) or test batteries combining data from the individual methods (accuracy 75%). These results suggest that computational methods are promising tools to identify effectively the potential human skin sensitizers without animal testing. Published 2016. This article has been contributed to by US Government employees and their work is in the public domain in the USA. Published 2016. This article has been contributed to by US

Contribution of human skin topography to the characterization of dynamic skin tension during senescence: morpho-mechanical approach

NASA Astrophysics Data System (ADS)

Zahouani, H.; Djaghloul, M.; Vargiolu, R.; Mezghani, S.; Mansori, M. E. L.

2014-03-01

The structuring of the dermis with a network of collagen and elastic fibres gives a three-dimensional structure to the skin network with directions perpendicular and parallel to the skin surface. This three-dimensional morphology prints on the surface of the stratum corneum a three dimensional network of lines which express the mechanical tension of the skin at rest. To evaluate the changes of skin morphology, we used a three-dimensional confocal microscopy and characterization of skin imaging of volar forearm microrelief. We have accurately characterize the role of skin line network during chronological aging with the identification of depth scales on the network of lines (z <= 60μm) and the network of lines covering Langer's lines (z > 60 microns). During aging has been highlighted lower rows for elastic fibres, the decrease weakened the tension and results in enlargement of the plates of the microrelief, which gives us a geometric pertinent indicator to quantify the loss of skin tension and assess the stage of aging. The study of 120 Caucasian women shows that ageing in the volar forearm zone results in changes in the morphology of the line network organisation. The decrease in secondary lines (z <= 60 μm) is counterbalanced by an increase in the depth of the primary lines (z > 60 μm) and an accentuation of the anisotropy index.

The effect of skin surface topography and skin colouration cues on perception of male facial age, health and attractiveness.

PubMed

Fink, B; Matts, P J; Brauckmann, C; Gundlach, S

2018-04-01

Previous studies investigating the effects of skin surface topography and colouration cues on the perception of female faces reported a differential weighting for the perception of skin topography and colour evenness, where topography was a stronger visual cue for the perception of age, whereas skin colour evenness was a stronger visual cue for the perception of health. We extend these findings in a study of the effect of skin surface topography and colour evenness cues on the perceptions of facial age, health and attractiveness in males. Facial images of six men (aged 40 to 70 years), selected for co-expression of lines/wrinkles and discolouration, were manipulated digitally to create eight stimuli, namely, separate removal of these two features (a) on the forehead, (b) in the periorbital area, (c) on the cheeks and (d) across the entire face. Omnibus (within-face) pairwise combinations, including the original (unmodified) face, were presented to a total of 240 male and female judges, who selected the face they considered younger, healthier and more attractive. Significant effects were detected for facial image choice, in response to skin feature manipulation. The combined removal of skin surface topography resulted in younger age perception compared with that seen with the removal of skin colouration cues, whereas the opposite pattern was found for health preference. No difference was detected for the perception of attractiveness. These perceptual effects were seen particularly on the forehead and cheeks. Removing skin topography cues (but not discolouration) in the periorbital area resulted in higher preferences for all three attributes. Skin surface topography and colouration cues affect the perception of age, health and attractiveness in men's faces. The combined removal of these features on the forehead, cheeks and in the periorbital area results in the most positive assessments. © 2018 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Proof-of-concept: 3D bioprinting of pigmented human skin constructs.

PubMed

Ng, Wei Long; Qi, Jovina Tan Zhi; Yeong, Wai Yee; Naing, May Win

2018-01-23

Three-dimensional (3D) pigmented human skin constructs have been fabricated using a 3D bioprinting approach. The 3D pigmented human skin constructs are obtained from using three different types of skin cells (keratinocytes, melanocytes and fibroblasts from three different skin donors) and they exhibit similar constitutive pigmentation (pale pigmentation) as the skin donors. A two-step drop-on-demand bioprinting strategy facilitates the deposition of cell droplets to emulate the epidermal melanin units (pre-defined patterning of keratinocytes and melanocytes at the desired positions) and manipulation of the microenvironment to fabricate 3D biomimetic hierarchical porous structures found in native skin tissue. The 3D bioprinted pigmented skin constructs are compared to the pigmented skin constructs fabricated by conventional a manual-casting approach; in-depth characterization of both the 3D pigmented skin constructs has indicated that the 3D bioprinted skin constructs have a higher degree of resemblance to native skin tissue in term of the presence of well-developed stratified epidermal layers and the presence of a continuous layer of basement membrane proteins as compared to the manually-cast samples. The 3D bioprinting approach facilitates the development of 3D in vitro pigmented human skin constructs for potential toxicology testing and fundamental cell biology research.

3D bioprinting of functional human skin: production and in vivo analysis.

PubMed

Cubo, Nieves; Garcia, Marta; Del Cañizo, Juan F; Velasco, Diego; Jorcano, Jose L

2016-12-05

Significant progress has been made over the past 25 years in the development of in vitro-engineered substitutes that mimic human skin, either to be used as grafts for the replacement of lost skin, or for the establishment of in vitro human skin models. In this sense, laboratory-grown skin substitutes containing dermal and epidermal components offer a promising approach to skin engineering. In particular, a human plasma-based bilayered skin generated by our group, has been applied successfully to treat burns as well as traumatic and surgical wounds in a large number of patients in Spain. There are some aspects requiring improvements in the production process of this skin; for example, the relatively long time (three weeks) needed to produce the surface required to cover an extensive burn or a large wound, and the necessity to automatize and standardize a process currently performed manually. 3D bioprinting has emerged as a flexible tool in regenerative medicine and it provides a platform to address these challenges. In the present study, we have used this technique to print a human bilayered skin using bioinks containing human plasma as well as primary human fibroblasts and keratinocytes that were obtained from skin biopsies. We were able to generate 100 cm 2 , a standard P100 tissue culture plate, of printed skin in less than 35 min (including the 30 min required for fibrin gelation). We have analysed the structure and function of the printed skin using histological and immunohistochemical methods, both in 3D in vitro cultures and after long-term transplantation to immunodeficient mice. In both cases, the generated skin was very similar to human skin and, furthermore, it was indistinguishable from bilayered dermo-epidermal equivalents, handmade in our laboratories. These results demonstrate that 3D bioprinting is a suitable technology to generate bioengineered skin for therapeutical and industrial applications in an automatized manner.

A novel model of human skin pressure ulcers in mice.

PubMed

Maldonado, Andrés A; Cristóbal, Lara; Martín-López, Javier; Mallén, Mar; García-Honduvilla, Natalio; Buján, Julia

2014-01-01

Pressure ulcers are a prevalent health problem in today's society. The shortage of suitable animal models limits our understanding and our ability to develop new therapies. This study aims to report on the development of a novel and reproducible human skin pressure ulcer model in mice. Male non-obese, diabetic, severe combined immunodeficiency mice (n = 22) were engrafted with human skin. A full-thickness skin graft was placed onto 4×3 cm wounds created on the dorsal skin of the mice. Two groups with permanent grafts were studied after 60 days. The control group (n = 6) was focused on the process of engraftment. Evaluations were conducted with photographic assessment, histological analysis and fluorescence in situ hybridization (FISH) techniques. The pressure ulcer group (n = 12) was created using a compression device. A pressure of 150 mmHg for 8 h, with a total of three cycles of compression-release was exerted. Evaluations were conducted with photographic assessment and histological analysis. Skin grafts in the control group took successfully, as shown by visual assessment, FISH techniques and histological analysis. Pressure ulcers in the second group showed full-thickness skin loss with damage and necrosis of all the epidermal and dermal layers (ulcer stage III) in all cases. Complete repair occurred after 40 days. An inexpensive, reproducible human skin pressure ulcer model has been developed. This novel model will facilitate the development of new clinically relevant therapeutic strategies that can be tested directly on human skin.

Clusterin associates with altered elastic fibers in human photoaged skin and prevents elastin from ultraviolet-induced aggregation in vitro.

PubMed

Janig, Elke; Haslbeck, Martin; Aigelsreiter, Ariane; Braun, Nathalie; Unterthor, Daniela; Wolf, Peter; Khaskhely, Noor M; Buchner, Johannes; Denk, Helmut; Zatloukal, Kurt

2007-11-01

Clusterin is a secreted glycoprotein with stress-induced expression in various diseased and aged tissues. It shares basic features with small heat shock proteins because it may stabilize proteins in a folding-competent state. Besides its presence in all human body fluids, clusterin associates with altered extracellular matrix proteins, such as beta-amyloid in Alzheimer senile plaques in the brain. Because dermal connective tissue alterations occur because of aging and UV radiation, we explored the occurrence of clusterin in young, aged, and sun-exposed human skin. Immunohistochemical analysis showed that clusterin is constantly associated with altered elastic fibers in aged human skin. Elastotic material of sun-damaged skin (solar elastosis), in particular, revealed a strong staining for clusterin. Because of the striking co-localization of clusterin with abnormal elastic material, we investigated the interaction of clusterin with elastin in vitro. A chaperone assay was established in which elastin was denatured by UV irradiation in the absence or presence of clusterin. This assay demonstrated that clusterin exerted a chaperone-like activity and effectively inhibited UV-induced aggregation of elastin. The interaction of both proteins was further analyzed by electron microscopy, size exclusion chromatography, and mass spectrometry, in which clusterin was found in a stable complex with elastin after UV exposure.

Clusterin Associates with Altered Elastic Fibers in Human Photoaged Skin and Prevents Elastin from Ultraviolet-Induced Aggregation in Vitro

PubMed Central

Janig, Elke; Haslbeck, Martin; Aigelsreiter, Ariane; Braun, Nathalie; Unterthor, Daniela; Wolf, Peter; Khaskhely, Noor M.; Buchner, Johannes; Denk, Helmut; Zatloukal, Kurt

2007-01-01

Clusterin is a secreted glycoprotein with stress-induced expression in various diseased and aged tissues. It shares basic features with small heat shock proteins because it may stabilize proteins in a folding-competent state. Besides its presence in all human body fluids, clusterin associates with altered extracellular matrix proteins, such as β-amyloid in Alzheimer senile plaques in the brain. Because dermal connective tissue alterations occur because of aging and UV radiation, we explored the occurrence of clusterin in young, aged, and sun-exposed human skin. Immunohistochemical analysis showed that clusterin is constantly associated with altered elastic fibers in aged human skin. Elastotic material of sun-damaged skin (solar elastosis), in particular, revealed a strong staining for clusterin. Because of the striking co-localization of clusterin with abnormal elastic material, we investigated the interaction of clusterin with elastin in vitro. A chaperone assay was established in which elastin was denatured by UV irradiation in the absence or presence of clusterin. This assay demonstrated that clusterin exerted a chaperone-like activity and effectively inhibited UV-induced aggregation of elastin. The interaction of both proteins was further analyzed by electron microscopy, size exclusion chromatography, and mass spectrometry, in which clusterin was found in a stable complex with elastin after UV exposure. PMID:17872975

Remittance spectroscopy of human skin in vivo.

PubMed

Geyer, A; Vilser, W; Karte, K; Wollina, U

1996-08-01

The skin is an easily accessible organ on which non-invasive examination methods can be applied. Recently spectroscopic methods have been introduced in characterization of skin under physiological and pathological conditions. To examine remittance spectroscopic qualities of human skin in vivo and to clarify the influence of selected test conditions, a single-beam spectrometer MCS 410 (Carl Zeiss, Jena, Germany) has been used. Remittance spectra readings were performed in 35 volunteers. Wavelength ranged from 362 nm to 780 nm. Individual remittance values and their standard deviations were obtained from 20 readings under standardized test conditions. The effect of pressure, rubbing, cooling, washing, greasing and degreasing on average remittance values was investigated. Statistical analysis was done with paired Student's f-test and Fisher's test. Pressure increased remittance values over a wide range of wavelength, peaking at 518 nm. Greasing and degreasing modified spectral remittance of shorter wavelength peaking around 362 nm. Rubbing and cooling did not induce significant variations of spectral remittance of skin. Spectral remittance provides an individual profile in human skin, which may be influenced by pressure and greasing/ degreasing. To establish standardized test conditions with a narrow range of intra-individual variation these items have to be kept constant.

Peptide Regulation of Skin Fibroblast Functions during Their Aging In Vitro.

PubMed

Lin'kova, N S; Drobintseva, A O; Orlova, O A; Kuznetsova, E P; Polyakova, V O; Kvetnoy, I M; Khavinson, V Kh

2016-05-01

The effect peptides KE, KED, AED and AEDG on proliferation (Ki-67), regeneration and aging (CD98hc), apoptosis (caspase-3), and extracellular matrix remodeling (MMP-9) in skin fibroblasts during their aging in culture were studied by immunofluorescent confocal microscopy. All studied peptides inhibited MMP-9 synthesis that increases during aging of skin fibroblasts and enhanced the expression of Ki-67 and CD98hc that are less intensively synthesized during cell aging. Peptides AED and AEDG suppressed caspase-dependent apoptosis that increases during aging of cell cultures.

Age, Health and Attractiveness Perception of Virtual (Rendered) Human Hair

PubMed Central

Fink, Bernhard; Hufschmidt, Carla; Hirn, Thomas; Will, Susanne; McKelvey, Graham; Lankhof, John

2016-01-01

The social significance of physical appearance and beauty has been documented in many studies. It is known that even subtle manipulations of facial morphology and skin condition can alter people’s perception of a person’s age, health and attractiveness. While the variation in facial morphology and skin condition cues has been studied quite extensively, comparably little is known on the effect of hair on social perception. This has been partly caused by the technical difficulty of creating appropriate stimuli for investigations of people’s response to systematic variation of certain hair characteristics, such as color and style, while keeping other features constant. Here, we present a modeling approach to the investigation of human hair perception using computer-generated, virtual (rendered) human hair. In three experiments, we manipulated hair diameter (Experiment 1), hair density (Experiment 2), and hair style (Experiment 3) of human (female) head hair and studied perceptions of age, health and attractiveness. Our results show that even subtle changes in these features have an impact on hair perception. We discuss our findings with reference to previous studies on condition-dependent quality cues in women that influence human social perception, thereby suggesting that hair is a salient feature of human physical appearance, which contributes to the perception of beauty. PMID:28066276

Using infrared and Raman microspectroscopies to compare ex vivo involved psoriatic skin with normal human skin

NASA Astrophysics Data System (ADS)

Leroy, Marie; Lefèvre, Thierry; Pouliot, Roxane; Auger, Michèle; Laroche, Gaétan

2015-06-01

Psoriasis is a chronic dermatosis that affects around 3% of the world's population. The etiology of this autoimmune pathology is not completely understood. The barrier function of psoriatic skin is known to be strongly altered, but the structural modifications at the origin of this dysfunction are not clear. To develop strategies to reduce symptoms of psoriasis or adequate substitutes for modeling, a deep understanding of the organization of psoriatic skin at a molecular level is required. Infrared and Raman microspectroscopies have been used to obtain direct molecular-level information on psoriatic and healthy human skin biopsies. From the intensities and positions of specific vibrational bands, the lipid and protein distribution and the lipid order have been mapped in the different layers of the skin. Results showed a similar distribution of lipids and collagen for normal and psoriatic human skin. However, psoriatic skin is characterized by heterogeneity in lipid/protein composition at the micrometer scale, a reduction in the definition of skin layer boundaries and a decrease in lipid chain order in the stratum corneum as compared to normal skin. A global decrease of the structural organization is exhibited in psoriatic skin that is compatible with an alteration of its barrier properties.

The effects of mucopolysaccharide polysulphate on hydration and elasticity of human skin.

PubMed

Wanitphakdeedecha, Rungsima; Eimpunth, Sasima; Manuskiatti, Woraphong

2011-01-01

Background. Mucopolysaccharide polysulphate (MPS) has been used in medicine as an anti-inflammatory and antithrombotic agent for over 50 years. Its chemical structure permits considerable hydrogen bonding with adjacent water molecules, which effectively leads to hydration of the surrounding tissue. In addition, it stimulates endogenous hyaluronate synthesis, resulting in an increase in water-binding capacity and viscoelasticity of the skin. Objective. To study the efficacy of 0.1% MPS on hydration and elasticity of human skin. Methods. The first part of this study was a randomized double blind placebo-controlled study which included 60 female volunteers aged 30-45 years with dry skin, defined by Corneometer CM 825. The volunteers were treated with either 0.1% MPS or vehicle control. All subjects were asked to apply 1 g of cream to their face twice daily for a total period of 4 weeks. Skin hydration and elasticity were measured at baseline and week 4 with Corneometer CM 825 and cutometer MPA 580, respectively, at forehead and both cheeks. The second part of this study focused on the efficacy of 0.1% MPS on skin hydration after single application. 20 female volunteers aged 30-45 years with dry skin, defined by Corneometer CM 825, were recruited to the study. All subjects were asked to apply 2 g of 0.1% MPS cream on entirely randomly selected forearm. Skin hydration at the middle of both forearms was measured at baseline, immediately after application, and every 1 hour after application for a period of 10 hours. Results. 57 subjects (28 in vehicle control group, 29 in MPS) completed treatment protocol. The baseline skin hydration of both groups was not significantly different (P = 0.47). Hower, there was a statistically significant difference in skin hydration at 4 weeks between MPS and placebo group (P = 0.01). Skin elasticity was significantly improved at week 4 in both groups (vehicle-control, P < 0.01, and MPS, P < 0.01). However, no significant

High-definition optical coherence tomography intrinsic skin ageing assessment in women: a pilot study.

PubMed

Boone, M A L M; Suppa, M; Marneffe, A; Miyamoto, M; Jemec, G B E; Del Marmol, V

2015-10-01

Several non-invasive two-dimensional techniques with different lateral resolution and measurable depth range have proved to be useful in assessing and quantifying morphological changes in skin ageing. Among these, only in vivo microscopy techniques permit histometric measurements in vivo. Qualitative and quantitative assessment of chronological (intrinsic) age-related (IAR) morphological changes of epidermis, dermo-epidermal junction (DEJ), papillary dermis (PD), papillary-reticular dermis junction and reticular dermis (RD) have been performed by high-definition optical coherence tomography in real time 3-D. HD-OCT images were taken at the internal site of the right upper arm. Qualitative HD-OCT IAR descriptors were reported at skin surface, at epidermal layer, DEJ, PD and upper RD. Quantitative evaluation of age-related compaction and backscattered intensity or brightness of different skin layers was performed by using the plugin plot z-axis profile of ImageJ(®) software permitting intensity assessment of HD-OCT (DICOM) images (3-D images). Analysis was in blind from all clinical information. Sixty, fair-skinned (Fitzpatrick types I-III) healthy females were analysed retrospectively in this study. The subjects belonged to three age groups: twenty in group I aged 20-39, twenty in group II aged 40-59 and twenty in group III aged 60-79. Only intrinsic ageing in women has been studied. Significant age-related qualitative and quantitative differences could be noticed. IAR changes in dermal matrix fibers morphology/organisation and in microvasculature were observed. The brightness and compaction of the different skin layers increased significantly with intrinsic skin ageing. The depth of visibility of fibers in RD increased significantly in the older age group. In conclusion, HD-OCT allows 3-D in vivo and real time qualitative and quantitative assessment of chronological (intrinsic) age-related morphological skin changes at high resolution from skin surface to a depth

Skin aging in patients with acquired immunodeficiency syndrome.

PubMed

de Aquino Favarato, Grace Kelly Naves; da Silva, Aline Cristina Souza; Oliveira, Lívia Ferreira; da Fonseca Ferraz, Mara Lúcia; de Paula Antunes Teixeira, Vicente; Cavellani, Camila Lourencini

2016-10-01

To evaluate the histomorphometric skin changes over aging patients with autopsied acquired immunodeficiency syndrome (AIDS). In 29 skin fragments of autopsied elderly (older than 50 years) and nonelderly patients with AIDS, epidermal thickness, the number of layers, the diameter of cells, the percentage of collagen and elastic fibers in the dermis, and the number and morphology of Langerhans cells were assessed. Statistical analysis was performed by SigmaStat 2.03 program. The thickness of the epidermis (92.55 × 158.94 μm), the number of layers (7 × 9 layers), and the diameter of the cells (13.27 × 17.6 μm) were statistically lower among the elderly. The quantity of collagen fibers (9.68 × 14.11%) and elastic fibers (11.89 × 15.31%) was also significantly lower in the elderly. There was a decrease in total (10.61 × 12.38 cel/mm(2)) and an increase in immature Langerhans cells (6.31 × 4.98 cel/mm(2)) in elderly patients with AIDS. The aging of the skin of patients with AIDS is amended in different histomorphometric aspects, the epidermis constituents suffer less pronounced changes in normal aging, and the dermis has more intense changes in elastic fibers and collagen. Copyright © 2016 Elsevier Inc. All rights reserved.

The relationship between in vitro cellular aging and in vivo human age.

PubMed Central

Schneider, E L; Mitsui, Y

1976-01-01

Differences between early and late passage cell cultures on the organelle and macromolecular levels have been attributed to cellular "aging". However, concern has been expressed over whether changes in diploid cell populations after serial passage in vitro accurately reflect human cellular aging in vivo. Studies were therefore undertaken to determine if significant differences would be observed in the in vitro lifespans of skin fibroblast cultures from old and young normal, non-hospitalized volunteers and to examine if parameters that change with in vitro "aging" are altered as a function of age in vivo. Statistically signigificant (P less than 0.05) decreases were found in the rate of fibroblast migration, onset of cell culture senescence, in vitro lifespan, cell population replication rate, and cell number at confluency of fibroblast cultures derived from the old donor group when compared to parallel cultures from young donors. No significant differences were observed in modal cell volumes and cellular macromolecular contents. The differences observed in cell cultures from old and young donors were quantitatively and qualitatively distinct from those cellular alterations observed in early and late passage WI-38 cells (in vitro "aging"). Therefore, although early and late passage cultures of human diploid cells may provide an important cell system for examining loss of replicative potential, fibroblast cultures derived from old and young human donors may be a more appropriate model system for studying human cellular aging. PMID:1068470

Is lack of sleep capable of inducing DNA damage in aged skin?

PubMed

Kahan, V; Ribeiro, D A; Egydio, F; Barros, L A; Tomimori, J; Tufik, S; Andersen, M L

2014-01-01

Skin naturally changes with age, becoming more fragile. Various stimuli can alter skin integrity. The aim of this study was to evaluate whether sleep deprivation affects the integrity of DNA in skin and exacerbates the effects of aging. Fifteen-month old female Hairless mice underwent 72 h of paradoxical sleep deprivation or 15 days of chronic sleep restriction. Punch biopsies of the skin were taken to evaluate DNA damage by single cell gel (comet) assay. Neither paradoxical sleep deprivation nor sleep restriction increased genetic damage, measured by tail movement and tail intensity values. Taken together, the findings are consistent with the notion that aging overrides the effect of sleep loss on the genetic damage in elderly mice. © 2014 S. Karger AG, Basel.

Induction of Skin-Derived Precursor Cells from Human Induced Pluripotent Stem Cells.

PubMed

Sugiyama-Nakagiri, Yoriko; Fujimura, Tsutomu; Moriwaki, Shigeru

2016-01-01

The generation of full thickness human skin from dissociated cells is an attractive approach not only for treating skin diseases, but also for treating many systemic disorders. However, it is currently not possible to obtain an unlimited number of skin dermal cells. The goal of this study was to develop a procedure to produce skin dermal stem cells from induced pluripotent stem cells (iPSCs). Skin-derived precursor cells (SKPs) were isolated as adult dermal precursors that could differentiate into both neural and mesodermal progenies and could reconstitute the dermis. Thus, we attempted to generate SKPs from iPSCs that could reconstitute the skin dermis. Human iPSCs were initially cultured with recombinant noggin and SB431542, an inhibitor of activin/nodal and TGFβ signaling, to induce neural crest progenitor cells. Those cells were then treated with SKP medium that included CHIR99021, a WNT signal activator. The induction efficacy from neural crest progenitor cells to SKPs was more than 97%. No other modifiers tested were able to induce those cells. Those human iPSC-derived SKPs (hiPSC-SKPs) showed a similar gene expression signature to SKPs isolated from human skin dermis. Human iPSC-SKPs differentiated into neural and mesodermal progenies, including adipocytes, skeletogenic cell types and Schwann cells. Moreover, they could be induced to follicular type keratinization when co-cultured with human epidermal keratinocytes. We here provide a new efficient protocol to create human skin dermal stem cells from hiPSCs that could contribute to the treatment of various skin disorders.

In vivo evaluation of some biophysical parameters of the facial skin of Indian women. Part I: variability with age and geographical locations.

PubMed

Colomb, L; Flament, F; Wagle, A; Agrawal, D

2018-02-01

India is a large country (a subcontinent) of about 3.3 million km 2 that covers large ranges in latitude and longitude. The last Indian census counted about 1.21 billion of inhabitants of many origins, creating a vast human diversity and skin types, the variability of which having been previously established. The present study aimed at deepening this knowledge through a set of biophysical measurements to describe, along the skin ageing process, the specificities of various Indian subjects living in different geographical locations. A total of 1204 women, aged 18-84 years, of all socio-economic status, were recruited in four Indian cities (Mumbai, Kolkata, Chennai and Delhi). Measurements of face skin colour properties, elastic properties, sebum production, skin pores and microrelief roughness were performed. With regard skin colour, this study indicates, with age, a darkening of very low amplitude that leads to an increased skin colour heterogeneity. In all subjects, at all ages, the ocular region (dark circles) presents a much darker pigmentation than the cheeks, creating a contrast that appears constant at all ages. In addition to an increased skin colour heterogeneity, a progressive alteration of the skin surface relief, increased sizes of skin pores, a loss of skin elasticity and a drop in sebum production, post-menopause, are observed. This study confirms, in Indian women, some skin ageing measurements found on women from other ethnic groups (i.e. sebum, firmness, wrinkles and pores size) and also identifies some Indian specificities: a high and constant contrast between the ocular region and the cheek colour, associated to a very slow darkening effect along the lifespan. © 2017 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Evaluation of a human bio-engineered skin equivalent for drug permeation studies.

PubMed

Asbill, C; Kim, N; El-Kattan, A; Creek, K; Wertz, P; Michniak, B

2000-09-01

To test the barrier function of a bio-engineered human skin (BHS) using three model drugs (caffeine, hydrocortisone, and tamoxifen) in vitro. To investigate the lipid composition and microscopic structure of the BHS. The human skin substitute was composed of both epidermal and dermal layers, the latter having a bovine collagen matrix. The permeability of the BHS to three model drugs was compared to that obtained in other percutaneous testing models (human cadaver skin, hairless mouse skin, and EpiDerm). Lipid analysis of the BHS was performed by high performance thin layered chromatography. Histological evaluation of the BHS was performed using routine H&E staining. The BHS mimicked human skin in terms of lipid composition, gross ultrastructure, and the formation of a stratum corneum. However, the permeability of the BHS to caffeine, hydrocortisone, and tamoxifen was 3-4 fold higher than that of human cadaver skin. In summary, the results indicate that the BHS may be an acceptable in vitro model for drug permeability testing.

Design and Fabrication of Human Skin by Three-Dimensional Bioprinting

PubMed Central

Lee, Vivian; Singh, Gurtej; Trasatti, John P.; Bjornsson, Chris; Xu, Xiawei; Tran, Thanh Nga; Yoo, Seung-Schik

2014-01-01

Three-dimensional (3D) bioprinting, a flexible automated on-demand platform for the free-form fabrication of complex living architectures, is a novel approach for the design and engineering of human organs and tissues. Here, we demonstrate the potential of 3D bioprinting for tissue engineering using human skin as a prototypical example. Keratinocytes and fibroblasts were used as constituent cells to represent the epidermis and dermis, and collagen was used to represent the dermal matrix of the skin. Preliminary studies were conducted to optimize printing parameters for maximum cell viability as well as for the optimization of cell densities in the epidermis and dermis to mimic physiologically relevant attributes of human skin. Printed 3D constructs were cultured in submerged media conditions followed by exposure of the epidermal layer to the air–liquid interface to promote maturation and stratification. Histology and immunofluorescence characterization demonstrated that 3D printed skin tissue was morphologically and biologically representative of in vivo human skin tissue. In comparison with traditional methods for skin engineering, 3D bioprinting offers several advantages in terms of shape- and form retention, flexibility, reproducibility, and high culture throughput. It has a broad range of applications in transdermal and topical formulation discovery, dermal toxicity studies, and in designing autologous grafts for wound healing. The proof-of-concept studies presented here can be further extended for enhancing the complexity of the skin model via the incorporation of secondary and adnexal structures or the inclusion of diseased cells to serve as a model for studying the pathophysiology of skin diseases. PMID:24188635

Design and fabrication of human skin by three-dimensional bioprinting.

PubMed

Lee, Vivian; Singh, Gurtej; Trasatti, John P; Bjornsson, Chris; Xu, Xiawei; Tran, Thanh Nga; Yoo, Seung-Schik; Dai, Guohao; Karande, Pankaj

2014-06-01

Three-dimensional (3D) bioprinting, a flexible automated on-demand platform for the free-form fabrication of complex living architectures, is a novel approach for the design and engineering of human organs and tissues. Here, we demonstrate the potential of 3D bioprinting for tissue engineering using human skin as a prototypical example. Keratinocytes and fibroblasts were used as constituent cells to represent the epidermis and dermis, and collagen was used to represent the dermal matrix of the skin. Preliminary studies were conducted to optimize printing parameters for maximum cell viability as well as for the optimization of cell densities in the epidermis and dermis to mimic physiologically relevant attributes of human skin. Printed 3D constructs were cultured in submerged media conditions followed by exposure of the epidermal layer to the air-liquid interface to promote maturation and stratification. Histology and immunofluorescence characterization demonstrated that 3D printed skin tissue was morphologically and biologically representative of in vivo human skin tissue. In comparison with traditional methods for skin engineering, 3D bioprinting offers several advantages in terms of shape- and form retention, flexibility, reproducibility, and high culture throughput. It has a broad range of applications in transdermal and topical formulation discovery, dermal toxicity studies, and in designing autologous grafts for wound healing. The proof-of-concept studies presented here can be further extended for enhancing the complexity of the skin model via the incorporation of secondary and adnexal structures or the inclusion of diseased cells to serve as a model for studying the pathophysiology of skin diseases.

The active natural anti-oxidant properties of chamomile, milk thistle, and halophilic bacterial components in human skin in vitro.

PubMed

Mamalis, Andrew; Nguyen, Duc-Huy; Brody, Neil; Jagdeo, Jared

2013-07-01

The number of skin cancers continues to rise, accounting for approximately 40% of all cancers reported in the United States and approximately 9,500 deaths per year. Studies have shown reactive oxygen species (ROS) type free radicals are linked to skin cancer and aging. Therefore, it is important for us to identify agents that have anti-oxidant properties to protect skin against free radical damage. The purpose of this research is to investigate the anti-oxidant properties of bisabolol, silymarin, and ectoin that are components from chamomile, milk thistle, and halophilic bacteria, respectively. We measured the ability of bisabolol, silymarin, and ectoin to modulate the hydrogen peroxide (H2O2)-induced upregulation of ROS free radicals in normal human skin fibroblasts in vitro. Using a flow cytometry-based assay, we demonstrated that varying concentrations of these natural components were able to inhibit upregulation of H2O2-generated free radicals in human skin fibroblasts in vitro. Our results indicate components of chamomile, milk thistle, and halophilic bacteria exhibit anti-oxidant capabilities and warrant further study in clinical trials to characterize their anti-cancer and anti-aging capabilities.

The Protective Role of Melanin Against UV Damage in Human Skin

PubMed Central

Brenner, Michaela; Hearing, Vincent J.

2009-01-01

Human skin is repeatedly exposed to ultraviolet radiation (UVR) that influences the function and survival of many cell types and is regarded as the main causative factor in the induction of skin cancer. It has been traditionally believed that skin pigmentation is the most important photoprotective factor, since melanin, besides functioning as a broadband UV absorbent, has antioxidant and radical scavenging properties. Besides, many epidemiological studies have shown a lower incidence for skin cancer in individuals with darker skin compared to those with fair skin. Skin pigmentation is of great cultural and cosmetic importance, yet the role of melanin in photoprotection is still controversial. This article outlines the major acute and chronic effects of UV radiation on human skin, the properties of melanin, the regulation of pigmentation and its effect on skin cancer prevention. PMID:18435612

Age and Hydration dependence of jowl and forearm skin firmness in young and mature women.

PubMed

Mayrovitz, Harvey N; Wong, Jennifer; Fasen, Madeline

2017-12-27

Quantitative assessment of possible linkages between skin's firmness and water content is useful for cosmetic and clinical purposes and to better understand features of advancing age. Our goals were to characterize age-related differential features in skin firmness in women and determine the relationship between skin firmness and indices of skin water. Skin firmness was quantified using handheld devices that measure the force to indent skin 0.3 and 1.3 mm (F0.3 and F1.3). Skin hydration was quantified using handheld devices that measured tissue dielectric constant (TDC) at 300 MHz to skin depths of 0.5 and 2.0-2.5 mm. All parameters were measured bilaterally in the jowl area and volar forearm of 60 women grouped by age <45 years (YOUNG) and ≥45 years old (MATURE). All measured parameters were bilaterally symmetrical at jowl and forearm. Forearm and jowl indentation forces were greater in YOUNG with statistically significant declines with advancing age with regression relations most evident at shallower indentation depths (P < .001). Quantitative relations for arm and jowl were F 0.3 = 0.256 × AGE + 32.7 mN and F 0.3 = -0.07 × AGE + 17.7 mN. Firmness was related to TDC values only when indentation force and TDC were assessed on the arm at the shallowest skin depths, as weakly related to firmness and was observed to change with age only when measured to a depth of 0.5 mm represented by TDC5 = 0.096 × AGE + 32.7. Experimental finding show clear differences in skin firmness between age-groups with skin hydration playing a minor role. Possible explanations and suggestions for further studies are provided. © 2017 Wiley Periodicals, Inc.

Systemic and topical drugs for aging skin.

PubMed

Kockaert, Michael; Neumann, Martino

2003-08-01

The rejuvenation of aging skin is a common desire for our patients, and several options are available. Although there are some systemic methods, the most commonly used treatments for rejuvenation of the skin are applied topically. The most frequently used topical drugs include retinoids, alpha hydroxy acids (AHAs), vitamin C, beta hydroxy acids, anti-oxidants, and tocopherol. Combination therapy is frequently used; particularly common is the combination of retinoids and AHAs. Systemic therapies available include oral retinoids and vitamin C. Other available therapies such as chemical peels, face-lifts, collagen, and botulinum toxin injections are not discussed in this article.

Measurements and Characterizations of Mechanical Properties of Human Skins

NASA Astrophysics Data System (ADS)

Song, Han Wook; Park, Yon Kyu

A skin is an indispensible organ for humans because it contributes to metabolism using its own biochemical functions and protects the human body from external stimuli. Recently, mechanical properties such as a thickness, a friction and an elastic coefficient have been used as a decision index in the skin physiology and in the skin care market due to the increased awareness of wellbeing issues. In addition, the use of mechanical properties is known to have good discrimination ability in the classification of human constitutions, which are used in the field of an alternative medicine. In this study, a system that measures mechanical properties such as a friction and an elastic coefficient is designed. The equipment consists of a load cell type (manufactured by the authors) for the measurements of a friction coefficient, a decompression tube for the measurement of an elastic coefficient. Using the proposed system, the mechanical properties of human skins from different constitutions were compared, and the relative repeatability error for measurements of mechanical properties was determined to be less than 2%. Combining the inspection results of medical doctors in the field of an alternative medicine, we could conclude that the proposed system might be applicable to a quantitative constitutional diagnosis between human constitutions within an acceptable level of uncertainty.