Age-Dependent Protective Effect of Selenium against UVA Irradiation in Primary Human Keratinocytes and the Associated DNA Repair Signature.

Few studies have focused on the protective role of selenium (Se) against skin aging and photoaging even though selenoproteins are essential for keratinocyte function and skin development. To the best of our knowledge, the impact of Se supplementation on skin cells from elderly and young donors has not been reported. Therefore, the main objective of our study was to evaluate the effects of Se supplementation on skin keratinocytes at baseline and after exposure to ultraviolet A (UVA) irradiation. Low doses of Se (30 nM) were very potently protective against UVA-induced cytotoxicity in young keratinocytes, whereas the protection efficiency of Se in old keratinocytes required higher concentrations (240 nM). Additionally, the DNA repair ability of the old keratinocytes drastically decreased compared with that of the young keratinocytes at baseline and after the UVA exposure. The Se supplementation significantly enhanced the DNA repair of 8-oxoguanine (8oxoG) only in the keratinocytes isolated from young donors. Therefore, aged keratinocytes have an increased vulnerability to oxidative DNA damage, and the Se needs in the elderly should be considered. Strengthening DNA repair activities with Se supplementation may represent a new strategy to combat aging and skin photoaging.

Effect of supplementation with Se-enriched yeast and factors influencing Se concentration in plasma of transplant recipients.

The aim of this study was to assess the bioavailability of selenium (Se) in Se-enriched yeast and the possible impact of age, sex and area of residence on the Se concentration in plasma in 179 transplant recipients, as Se clinical effects in the prevention of cutaneous epithelial lesions in organ transplant recipients has been reported elsewhere. Subjects were randomized to receive either 200 microg Se/day (group 1:91 patients) or placebo (group 2: 88 patients) for 3 years. Plasma Se levels were measured at the beginning of the study and after 4, 12, 24 and 36 months of Se or placebo supplementation. Initial plasma Se levels were 90.9+/-26.1 microg/L for placebo and 94.0+/-25.3 microg/L for Se-supplemented groups. At baseline, the Se level was not linked to sex and age but to area of residence, although the number of subjects in each area was insufficient to draw any conclusions. Plasma Se levels were statistically lower in cases of liver transplant compared to kidney and heart transplant (p=0.03). Over the 3-year period of supplementation, plasma Se in the supplemented subjects was significantly higher than in the placebo group (p<0.01) and there was an interaction (p<0.01) between supplementation and time for plasma Se. Supplementation with Se-enriched yeast significantly increased the Se concentration in plasma of the patients to a plateau: the mean plasma Se of the Se-supplemented patients increased to 164.7+/-35.8 microg/L at 4 months and then remained similar at 12 (176.1+/-48.3 microg/L), 24 (176.1+/-54.2 microg/L) and 36 (182.2+/-46.4 microg/L) months.

[Acne, pregnant women and zinc salts: a literature review]. / Acné de la femme enceinte et sels de zinc: revue de la littérature.

BACKGROUND: Acne in adult women is a common reason for dermatological consultation. Dermatologists are occasionally confronted with the problem of treating acne in women who are either pregnant or seeking to become pregnant, or in breast-feeding women, in whom zinc salts are the only form of systemic treatment that may be envisaged. PATIENTS AND METHODS: The purpose of our study was to provide an overview of existing data concerning the use of the zinc salts in pregnant and breast-feeding women based on a literature review, a survey of prescription of zinc gluconate by French dermatologists, and finally, analysis of French pharmacovigilance data. RESULTS: There are many studies involving the use of zinc supplements during pregnancy. In these studies, more than 2500 pregnant women were given zinc at different doses. None of these studies described any abnormalities, congenital malformation, harmful effects or risk for the foetus associated with the use of zinc during pregnancy at doses below 75 mg/day. Although there are fewer studies of the use of zinc supplements in breast-feeding women, no abnormalities associated with use of zinc during breast-feeding have been reported. According to the results of the prescription survey, around 10,000 pregnant women and 2000 breast-feeding women are treated each year for acne using zinc gluconate, with only four serious adverse events involving zinc being reported since the initial introduction of the product, and with zinc having a doubtful causal relationship. DISCUSSION: Zinc plays a key role in our body's physiology, since it is involved in the activities of many enzymes. In addition, zinc requirements increase during pregnancy, mainly because of its utilisation during embryogenesis and fetal development. This literature review shows that use of zinc salts in pregnant women is beneficial in those with zinc deficiency but that it has no harmful effects in those without zinc deficiency.

Neutralizing immunogenicity of transgenic carrot (Daucus carota L.)-derived measles virus hemagglutinin.

Although edible vaccines seem to be feasible, antigens of human pathogens have mostly been expressed in plants that are not attractive for human consumption (such as potatoes) unless they are cooked. Boiling may reduce the immunogenicity of many antigens. More recently, the technology to transform fruit and vegetable plants have become perfected. We transformed carrot plants with Agrobacterium tumefaciens to generate plants (which can be eaten raw) transgenic for an immunodominant antigen of the measles virus, a major pathogen in man. The hemagglutinin (H) glycoprotein is the principle target of neutralizing and protective antibodies against measles. Copy numbers of the H transgene were verified by Southern blot and specific transcription was confirmed by RT-PCR. The H protein was detected by western blot in the membrane fraction of transformed carrot plants. The recombinant protein seemed to have a 8% lower molecular weight than the viral protein. Although this suggests a different glycosylation pattern, proper folding of the transgenic protein was confirmed by conformational-dependent monoclonal antibodies. Immunization of mice with leaf or root extracts induced high titres of IgG1 and IgG2a antibodies that cross-reacted strongly with the measles virus and neutralized the virus in vitro. These results demonstrate that transgenic carrot plants can be used as an efficient expression system to produce highly immunogenic viral antigens. Our study may pave the way towards an edible vaccine against measles which could be complementary to the current live-attenuated vaccine.