Aspects of cutaneous ageing

Maintaining skin health in older people

Skin changes associated with age are inevitable. Ageing is associated with structural and functional changes of the skin that result in increased vulnerability. The most common functional skin changes are dryness (xerosis), which causes itching and discomfort, and skin fragility, increasing patients' vulnerability to skin damage. Dry skin and itching have a significant effect on older people, which can be further exacerbated by products used for washing and bathing. The management of dry skin and itching is fundamental to older people's care and nurses should act in their best interests to ensure that the potential for skin damage is addressed. However, many older people are often reluctant to discuss the problem, are embarrassed and will self-treat or try to hide an underlying problem such as incontinence or worries about being infectious or dirty. This can be challenging when managing their skin care because of under-reporting, self-medicating or the assumption that it is 'just old age'.

Skin Burn Associated With Photochemotherapy

OBJECTIVE

psoralen and ultraviolet A (PUVA) phototherapy (PT) has become a standard treatment for several severe skin diseases. Photosensitization is done by oral psoralen intake. In minor cases, PUVA can lead to skin changes like erythema and hyperpigmentation. However, it can also lead to severe burn injuries when exposed to extensive UV light. This makes the treatment in a burn center inevitable.

METHODS

We report the clinical observation of a 38-year-old man presenting with an extensive burn injury caused by sun tanning after PUVA PT.

CONCLUSIONS

There are just few cases of extensive burns induced by PUVA PT. Prevention becomes manifest in patient information, correct calculation of dosage, evaluation of photosensitivity, and close observation. In cases of severe burn injuries, patients should be referred to a burn center for optimal conservative treatment. Surgical intervention is usually not necessary.

Green tea flavanols protect human γB-crystallin from oxidative photodamage

Age related cataract is a major cause of visual loss worldwide that is a result of opacification of the eye lens proteins. One of the major reasons behind this deterioration is UV induced oxidative damage. The study reported here is focused on an investigation of the oxidative stress induced damage to γB-crystallin under UV exposure. Human γB-crystallin has been expressed and purified from E. coli. We have found that epicatechin gallate (ECG) has a higher affinity towards the protein compared to epigallocatechin (EGC). The in vitro study of UV irradiation under oxidative damage to the protein in the presence of increasing concentrations of GTPs is indicative of their effective role as potent inhibitors of oxidative damage. Docking analyses show that the GTPs bind to the cleft between the domains of human γB-crystallin that may be associated with the protection of the protein from oxidative damage.

Increase of gingival matured dendritic cells number in elderly patients with chronic periodontitis

OBJECTIVE

The purpose of this study was to evaluate the inflammatory cell subset proportions in the upper gingival connective tissue, including mature dendritic cells (DC) in elderly and younger patients with generalized chronic periodontitis in order to further understand the effect of aging on gingival inflammatory phenomenon.

METHODS

Gingival tissue specimens presenting chronic periodontitis from 8 elderly patients aged >75 (test group, group T) and from 8 younger patients aged 50-60 (considered as controls, group C) were analysed by immunohistochemistry using monoclonal antibodies against CD45RB, CD4, CD8, CD19, CD68, DC-SIGN, DC-LAMP molecules. The number of each immunolabelled cells subset was counted using image analysis.

RESULTS

The difference in the number of CD45RB+leucocytes in the upper gingival connective tissue between groups was not significant permitting to use it as reference. As compared to group C, the lymphocyte subsets/CD45RB+leucocytes ratios tended to decrease in group T but the decrease was significant only for CD4+T lymphocytes/CD45RB+cells ratio (p<0.03). On the opposite, the ratios of antigen-presenting cells DC-SIGN+cells/CD45RB+cells and DC-LAMP+cells/CD45RB+cells were significantly increased (p<0.03 and <0.0001, respectively) in group T. Moreover, in group T the DC-LAMP+cells/DC-SIGN+cells ratio was significantly increased (p<0.05) showing an increased number of matured dendritic cells.

CONCLUSION

During chronic periodontitis in elderly patients, our results show a decrease in the ratio of gingival CD4+lymphocyte subset associated with an increase in the ratios of antigen-presenting cells subsets and more particularly maturated DC-LAMP+dendritic cells.

Immunohistochemical determination of the P15 protein expression in cutaneous squamous cell carcinoma

The tumor suppressor gene p15(INK4b) is a cyclin-dependent kinase inhibitor, in which its inactivation has been determined in primary tumors and in several tumor-derived cell lines. The precise role of p15(INK4b) protein expression in cutaneous squamous cell carcinoma (SCC) is currently not known. In a previous study, we have shown the frequent occurrence of allelic imbalance/loss of heterozygosity in cutaneous SCC using two microsatellite markers flanking the p15(INK4b) gene. This study is a continuation of our previous study and aims to determine the possible role of p15(INK4b) protein expression in the genesis of cutaneous SCC. P15(INK4b) protein expression was determined using immunohistochemical approach in 107 cases of cutaneous SCC tissue arrays and 19 cases of normal human skin tissues. The expression of p15(INK4b) was significantly reduced in the cutaneous SCC cases as compared with normal human skin (p = 0.017 and p < 0.05). However, there were no significant relationship between clinicopathologic variables of the patients (age, sex and tumor grade) and p15(INK4b) protein expression. The absence of p15(INK4b) expression in the majority of tissue microarray cores of cutaneous SCC indicated that p15(INK4b) could possibly be involved in the pathogenesis of cutaneous SCC.

Do Langerhans cells behave similarly in elderly and younger patients with chronic periodontitis?

OBJECTIVE

The purpose of this study was to compare the number, the distribution and the expression of markers of maturation of Langerhans cells (LC) in elderly and younger patients with chronic periodontitis in order to evidence the effect of aging on LC in inflammatory gingival tissue.

METHODS

Gingival tissue specimens presenting chronic periodontitis from 8 elderly patients aged >75 (group E) and from 8 younger patients aged 50-60 (considered as controls, group C) were used for immunohistochemistry with monoclonal antibodies against CD45RB (leucocytes), CD1a (LC), markers of LC maturation (DC-LAMP, CD83) and number of immunolabelled cell subsets was evaluated using image analysis.

RESULTS

The difference in the number of CD45RB+ leucocytes in the upper connective tissue between groups was not significant. In group E, the number of CD1a+ LC was significantly decreased (P<0.002) in the epithelium and significantly increased (P<0.0004) in the upper connective tissue. Furthermore, in group E, intraepithelial CD1a+ LC are more often observed in the upper epithelium and their dendritic processes were shorter and less numerous. Concerning the expression of markers of maturation, the numbers of intraepithelial DC-LAMP+ cells and CD83+ cells were significantly increased (P<0.0007 and P<0.02, respectively) in group E.

CONCLUSION

During chronic periodontitis in elderly patients, the decrease in the number of intraepithelial LC and the alteration of dendritic processes could be balanced by a cellular distribution often observed in the upper epithelium associated with changes in cell maturation in response to bacterial elements.

Phototherapy with narrowband vs broadband UVB

Phototherapy with ultraviolet (UV) radiation of wavelengths between 280 and 320 nm (UVB) is a safe and effective treatment for a variety of diseases. In addition to standard broadband UVB (bUVB), narrowband phototherapy with fluorescent bulbs emitting near monochromatic UV around 311 nm (nUVB) has become an important treatment for diseases such as psoriasis, atopic dermatitis and vitiligo. In addition to these indications, the number of diseases for which nUVB phototherapy is reported to be effective is continuously growing. The differential effects of nUVB phototherapy in comparison to other UV wavelengths as well as established and new indications for this treatment modality are reviewed.

Age-dependent response of energy metabolism of human skin to UVA exposure: an in vivo study by 31P nuclear magnetic resonance spectroscopy

PURPOSE

The aim of our study was to evaluate the in vivo energy metabolism of human skin as a function of age, in conditions of rest and after a mild stress caused by a suberythemal UVA irradiation.

METHODS

The kinetics of UVA-induced modifications in high-energy phosphorylated metabolites of young and old skins were non-invasively monitored over a period of 24 h using 31P nuclear magnetic resonance spectroscopy. In vivo 31P spectra were obtained on the ventral aspect of the wrist, using a NMR Imaging Spectrometer equipped with a double-tuned surface coil. Concentrations of phosphocreatine, inorganic phospate, adenosine tri-phosphate, phosphomono and phosphodiesters were calculated from the spectra and results were expressed as relative concentrations. A total of 20 subjects were enrolled in this study (n = 10 for the age group below 25 years and n = 10 for the age group above 55 years). A second experiment was then performed on 10 old subjects (mean age 60) who were treated on one wrist, twice a day for one month prior to UVA irradiation, with a product that contained active ingredients to restore barrier function and modulate the inflammatory response, the other wrist being an untreated control.

RESULTS

Baseline levels of phosphorylated metabolites were similar in young and old skins. A suberythemal dose of UVA (6 J.cm-2) led to a significant decrease in the PCr/Pi ratio (index of energy status) and a significant increase in the PME/PDE ratio (index of cellular turnover rate of lipid-related metabolites) within 1 h. The observed variations were transient and the recovery was complete at T + 24 h post-UVA, although recovery was significantly slower in the older group. The disturbances were significantly reduced after treatment of the older skin with a formula that restored barrier function of the stratum corneum and modulated the inflammatory response.

CONCLUSION

(i) baseline levels of energy metabolites in skin do not seem to vary with age; (ii) low dose UVA irradiation induces a rapid response in the energy metabolism of the skin; (iii) the kinetics of the response and recovery after an aggression by UVA suggest that older skin has significantly less energy rebound after a stress situation than younger skin; (iv) the energy reserve in older skin can be protected efficiently against UVA-induced stress by restoring barrier function and modulating the inflammatory response.

Spatial variation of acoustic parameters in human skin: an in vitro study between 22 and 45 MHz

This study of spatial variance of acoustic parameters was performed on eight nonfrozen samples of female abdominal skin (women 46.5 +/- 12.2 years old), obtained during plastic surgery. Intra- and interindividual variations are discussed on the basis of estimations of three acoustic parameters (slope of attenuation- beta; integrated attenuation coefficient- IAC; integrated backscattering coefficient- IBC) and one texture parameter (based on two estimators of effective density of scatterers: alpha(2) and alpha(1/2)) as a function of surface area and depth of acquisition in the frequency range 22 to 45 MHz. Values of intraindividual variations varied from 7.1% for IAC to 23.2% for IBC, and significantly decreased at a ratio between 1.2 to 2.3 when the acquisition surface area was increased from 4 mm(2) to 1 cm(2). Interindividual variations were higher than intraindividual variations, and varied from 14.2% for alpha(1/2) to 51% for IBC. The mean values (+/- SD) for all specimens combined, estimated with a large number of independent radiofrequency (RF) lines (400) and for a surface area of exploration of 4 cm(2), were 1.06 +/- 0.17 dB cm(-1) MHz(-1) for beta, 135 +/- 37 dB cm(-1) for IAC, (3.7 +/- 1.9) x 10(-2) cm(-1) sr(-1) for IBC, 1.40 +/- 0.17 scatterers/resolution cell for alpha(2) and 1.32 +/- 0.27 scatterers/resolution cell for alpha(1/2). Finally, attenuation micro(f) and backscattering coefficient sigma(b)(f) were compared to published results for the same parameters measured in human skin.

Cigarette smoking associated with premature facial wrinkling: image analysis of facial skin replicas

BACKGROUND

Despite the obvious relation between smoking and facial wrinkling, grossly undetectable wrinkling and the consequences of smoking on the face have been poorly studied.

OBJECTIVE

To assess the risk factor of cigarette smoking on the development of premature facial wrinkling.

METHODS

One hundred and twenty-three nonsmokers, 160 current smokers, and 67 past smokers, aged 20-69 years, were studied. Cigarette smoking status, weight changes, average sun exposure time (recreational and occupational) in 1 month, and past medical and facial cosmetic surgery were quantified by self-questionnaire. Computerized image analysis of silicone skin replicas was used in addition to clinical visual measurement, and a severity score based on predetermined criteria was assigned to each patient.

RESULTS

Current smokers have a higher degree of facial wrinkling than nonsmokers and past smokers. Past smokers who smoked heavily at a younger age show less facial wrinkling than current smokers. In the analysis, which was adjusted for age group, the relative risk of moderate to severe wrinkling for current smokers compared with nonsmokers was 2.72 (confidence interval, CI: 1.32-3.21, P < 0.05). In current smokers, the relative risks associated with more than 19 pack-years and 11-19 pack-years of smoking compared with nonsmokers were 2.93 (CI: 1.14-4.1, P < 0.05) and 1.75 (CI: 1.54-3.67, P < 0.05), respectively. On image analysis of facial skin replicas, the mean values of Ra (arithmetic average roughness), Rz (average roughness), and Rt (distance between the highest and lowest values) of current smokers were higher than those of nonsmokers and past smokers in all age groups. This indicates a strong correlation between cigarette smoking and skin wrinkling. In addition, microscopic superficial wrinkling (Ra and Rt) was noted in current smokers in the younger age group (20-39 years).

CONCLUSIONS

This study suggests that attention should be paid to smoking-associated facial wrinkling (not evident from a visual assessment) in young people and added to the list of disorders seemingly caused by smoking.

Chronological ageing and photoageing of dendritic cells

Ageing involves the whole organism, including the immune system. Age-dependent alterations of immune functions are located in both the adaptive and innate parts of the immune system. The most important cell type of the innate immune system are the dendritic cells, because their capacity to induce primary immune responses via professional antigen presentation is crucial for the initiation of the adaptive immune response. Evidence exists that dendritic cells of the systemic immune system, represented by lymph-node and blood-derived dendritic cells, as well as of local immunity, represented by Langerhans cells of the skin, participate in ageing processes. In animal models of older mice, dendritic cells of lymph nodes show degenerative characteristics with decreased adhesion molecule expression, less dendrite formation, and reduced antigen trapping capacity, which together imply disruption of functional activity. In contrast, dendritic cells generated from peripheral blood of elderly people were not impaired in their capacity to induce T-cell responses. Together, these findings indicate that in old individuals in vivo dendritic cells of the systemic immune system are reduced in their functional capacity to stimulate immune responses, whereas in vitro generated dendritic cells are fully functional, and therefore might be used in therapeutic approaches to treat age-associated malfunctions of the immune system. Thus far, only morphological descriptions about age-associated changes of dendritic cells (in particular the Langerhans cells) of the skin exist. In the skin, effects of naturally occurring ageing have to be differentiated from UV-radiation-induced ageing processes. The hallmark of Langerhans cell changes in natural as well as UV-induced skin ageing is their reduction in cell number within the epidermis. In addition, they show an atrophic morphology with less dendrites, and less Birbeck granules. It is assumed that these morphological changes are associated with loss of dendritic cell functions, and that this contributes to age-associated development of skin cancer. Therapeutic strategies against natural and UV-induced skin ageing should include a reduction of these changes of Langerhans cells in order to strengthen the immunological functions of the body's outer surface.

Nutritional skin care: health effects of micronutrients and fatty acids

Human skin is continuously exposed to internal and external influences that may alter its condition and functioning. As a consequence, the skin may undergo alterations leading to photoaging, inflammation, immune dysfunction, imbalanced epidermal homeostasis, or other skin disorders. Modern nutritional science is developing new insights into the relation between food intake and health, and effects of food ingredients may prove to be biologically relevant for optimal skin condition. The objective of this review was to evaluate the present knowledge about the interrelation of nutrients and skin, particularly the photoprotective effects of nutrients, the influences of nutrients on cutaneous immune responses, and therapeutic actions of nutrients in skin disorders. The nutrients of focus were vitamins, carotenoids, and polyunsaturated fatty acids. Supplementation with these nutrients was shown to provide protection against ultraviolet light, although the sun-protection factor was relatively small compared with that of topical sunscreens. An increase in delayed-type hypersensitivity skin responses after supplementation with nutrients has proven beneficial, especially in elderly people, and may boost cell-mediated immunity. Dietary consumption of certain plants or fish oil is known to modulate the balance of lipid inflammatory mediators and, therefore, is valuable in the treatment of inflammatory skin disorders. It was concluded that nutritional factors exert promising actions on the skin, but information on the effects of low-to-moderate doses of nutrients consumed long term by healthy individuals is obviously lacking, as are data on direct effects on basal skin properties, including hydration, sebum production, and elasticity.

Attenuation of DNA damage in the dermis and epidermis of the albino hairless mouse by chronic exposure to ultraviolet-A and -B radiation

Mammalian skin is vulnerable to the photocarcinogenic and photoaging effects of solar UV radiation and defends itself using a variety of photoprotective responses including epidermal thickening, tanning and the induction of repair and antiradical systems. We treated Skh-1 albino hairless mice for 60 days with ultraviolet-A (UVA) or ultraviolet-B (UVB) radiation and measured the frequency of cyclobutane pyrimidine dimers and pyrimidine(6-4)pyrimidone photoproducts induced by a single acute sunburn dose of UVB at different stages of the chronic treatment. We found that both UVA and UVB exposure produced a photoprotective response in the dermis and epidermis and that the degree of photoproduct attenuation was dependent on dose, wavelength and the type of damage induced. Although epidermal thickening was important, our data suggest that UV protective compounds other than melanin may be involved in mitigating the damaging effects of sunlight in the skin.

Cell cycle control, checkpoint mechanisms, and genotoxic stress

The ability of cells to maintain genomic integrity is vital for cell survival and proliferation. Lack of fidelity in DNA replication and maintenance can result in deleterious mutations leading to cell death or, in multicellular organisms, cancer. The purpose of this review is to discuss the known signal transduction pathways that regulate cell cycle progression and the mechanisms cells employ to insure DNA stability in the face of genotoxic stress. In particular, we focus on mammalian cell cycle checkpoint functions, their role in maintaining DNA stability during the cell cycle following exposure to genotoxic agents, and the gene products that act in checkpoint function signal transduction cascades. Key transitions in the cell cycle are regulated by the activities of various protein kinase complexes composed of cyclin and cyclin-dependent kinase (Cdk) molecules. Surveillance control mechanisms that check to ensure proper completion of early events and cellular integrity before initiation of subsequent events in cell cycle progression are referred to as cell cycle checkpoints and can generate a transient delay that provides the cell more time to repair damage before progressing to the next phase of the cycle. A variety of cellular responses are elicited that function in checkpoint signaling to inhibit cyclin/Cdk activities. These responses include the p53-dependent and p53-independent induction of Cdk inhibitors and the p53-independent inhibitory phosphorylation of Cdk molecules themselves. Eliciting proper G1, S, and G2 checkpoint responses to double-strand DNA breaks requires the function of the Ataxia telangiectasia mutated gene product. Several human heritable cancer-prone syndromes known to alter DNA stability have been found to have defects in checkpoint surveillance pathways. Exposures to several common sources of genotoxic stress, including oxidative stress, ionizing radiation, UV radiation, and the genotoxic compound benzo[a]pyrene, elicit cell cycle checkpoint responses that show both similarities and differences in their molecular signaling.

Dose- and wavelength-dependent oxidation of crystallins by UV light--selective recognition and degradation by the 20S proteasome

The lens of the human eye is a suitable model for age-related alterations at the molecular level. Age-related cataract formation is closely related to the accumulation of oxidatively altered proteins. In this study the influence of UV-A, UV-B, and UV-C irradiation on the proteolytic susceptibility of alpha-, betaL-, and betaH-crystallins by the isolated 20S proteasome was investigated. The proteins were irradiated with 280, 300, and 350 nm monochromatic light. Changes of the physical properties of the crystallins were characterized by absorbance measurements at 280 nm, fluorescence spectra, and SDS-PAGE-electrophoresis. The proteolytic susceptibility of crystallins was maximal after irradiation at 280 nm and three- to fivefold lower at 300 nm. Irradiation at 350 nm was not able to initiate proteolysis, probably due to protein-aggregate formation of higher molecular weight, as shown by SDS-PAGE. The damage of crystallins by UV-C light might be a signal for its proteolytic degradation by the 20S proteasome, whereas UV-B and UV-A do not increase the proteolytic susceptibility to the same extent but promote the formation of crosslinked proteins. Therefore, irradiation with UV, which is not followed by an increase in the proteolytic susceptibility, is accompanied by the formation of crosslinked proteins. It was concluded, that also long UV-B and UV-A may be involved in age-related alterations of the human lens and cataract formation.

An oral approach to the treatment of photodamaged skin: a pilot study

In recent publications much attention has focused on skin changes as a consequence of ageing. During life many internal and external factors have an influence on the condition of the skin but ultraviolet radiation seems to be a major factor in both benign and malignant alterations. To retard the deterioration process, more than cosmetic concern is necessary. In a pilot study, a fish protein product is shown to have the capacity to ameliorate, both objectively and subjectively, the symptoms of photo-aged skin. Recommendations are made for further evaluation.