During secondary immune responses, Ab-opsonized bacteria are efficiently taken up via FcRs by dendritic cells. We now demonstrate that this process induces cross-talk between FcRs and TLRs, which results in synergistic release of several inflammatory cytokines, as well as altered lipid metabolite profiles. This altered inflammatory profile redirects Th1 polarization toward Th17 cell responses. Interestingly, GM-CSF–producing Th cells were synergistically evoked as well, which suggests the onset of polyfunctional Th17 cells. Synergistic cytokine release was dependent on activation via MyD88 and ITAM signaling pathways through TLRs and FcRs, respectively. Cytokine regulation occurred via transcription-dependent mechanisms for TNF-α and IL-23 and posttranscriptional mechanisms for caspase-1–dependent release of IL-1β. Furthermore, cross-talk between TLRs and FcRs was not restricted to dendritic cells. In conclusion, our results support that bacteria alone initiate fundamentally different immune responses compared with Ab-opsonized bacteria through the combined action of two classes of receptors and, ultimately, may refine new therapies for inflammatory diseases.

The trace element selenium is an essential micronutrient for human health and its low levels in serum are implicated in the pathogenesis of several chronic diseases. Therefore, the determination of total selenium in serum may contribute to the assessment of the health and nutritional status of certain populations. The objective of the present work was to determine total selenium in the serum of 506 healthy volunteers that participated in the ATTICA study. Selenium was determined in serum by using the technique of inductively coupled plasma mass spectrometry. The mean serum selenium concentration was determined to be 91.8 +/- 33.7 microg/L (N = 506); 87.6% of women and 88.5% of men had serum selenium concentration below 125 microg/L, the cutoff considered to be required for optimal glutathione peroxidase activity. No association was found between serum selenium levels and the gender of the participants while a significant decline of selenium with age (p < 0.0001) was observed. According to our results, no anthropometric, lifestyle, nutritional, or biochemical indices were able to affect the association between serum selenium and age. This result may indicate that other factors such as selenium distribution as well as retention may be affecting the relationship between serum selenium and age.

Nowadays, there is huge interest in natural products obtained from marine organisms that can promote a state of health and well-being for humans. Microalgae represent a primary source of bioactive compounds that could be used as functional ingredients in cosmetic formulations. The aim of the present study is to evaluate, for the first time, the effects of Nannochloropsis gaditana extract against oxidative stress in human primary fibroblasts so as to investigate the potential applications of it in cosmetics. To gain an insight into the molecular mechanisms of N. gaditana bioactivity, we developed a new RT-qPCR platform for studying transcript accumulation for an array of selected genes (up to 100) involved in many skin-related processes including anti-aging, hydration, oxidative stress response, and DNA damage. For the oxidative stress evaluation, H 2 O 2 was used as a stressor. The study of the transcript accumulation of genes revealed that N. gaditana extract exhibits skin protection properties by mediating oxidative responses and apoptosis (including SOD1, GPX1, BID), positively regulates genes involves in skin texture and hydration (including AQP3, Col6A1, FBN1) and modulates the expression of genes involved in skin irritation, DNA damage and aging (including IL1R, PCNA, FOXO3). These findings indicate that the specific N. gaditana extract possesses significant in vitro skin protection activity against induced oxidative stress, and provide new insights into the beneficial role of microalgae bioactive compounds in cosmetic formulations protecting skin from oxidative stress.

No abstract

The narrow gap between essentiality and toxicity of selenium requires detailed investigations on selenium metabolism in order to find suitable indicators for the selenium status in the human body. Current methods for quantitative selenium speciation in human urine are based on separation by high-performance liquid chromatography (HPLC) coupled online with elemental mass spectrometry (MS), and the potential of molecular MS detection techniques for the reliable identification and quantification of selenosugars in crude human urine has not been utilized. Now we report the development of an HPLC tandem mass spectrometric (MS/MS) method for the reliable determination in crude human urine of three significant selenium urinary metabolites, collectively termed selenosugars, namely methyl 2-acetamido-2-deoxy-1-seleno-beta-D-galactopyranoside (SeGalNAc), methyl 2-acetamido-2-deoxy-1-seleno-beta-D-glucopyranoside (SeGluNAc) and methyl 2-amino-2-deoxy-1-seleno-beta-D-galactopyranoside (SeGalNH2). Reversed-phase HPLC, with and without cation-exchange guard columns, was applied for the separation of the selenosugars, and atmospheric pressure chemical ionization (APCI) and selected reaction monitoring (SRM) were used for selective and sensitive detection. The collision-induced dissociation behaviour of the selenosugars was studied in detail using APCI triple quadrupole MS/MS and electrospray ion trap MS. The developed method was applied to urine samples collected prior to and after selenium supplementation for the quantification of SeGalNAc using both external calibration and the method of standard additions. Additionally, SeGalNH2 was detected in urine samples after Se supplementation. Finally, neutral loss scanning was explored as a possible method for the detection of unknown methyl-selenosugars.

In this study, a method, based on dual column affinity chromatography hyphenated to isotope dilution inductively coupled plasma-quadrupole MS, was developed for selenium determination in selenoprotein P, glutathione peroxidase, and selenoalbumin in human serum samples from a group of healthy volunteers (n=399). Method improvement was achieved using methanol-enhanced isotope dilution which resulted in improved sensitivity and removal of isobaric interferences. Although no human serum reference materials are currently certified for their selenium species levels, method development was conducted using human serum reference material BCR 637 and 639 as their Se species content has been reported in the previous studies, and thus comparisons were possible. The mean selenium concentrations determined for the 399 healthy volunteer serum samples were 23 ± 10 ng Se mL(-1) for glutathione peroxidase, 49 ± 15 ng Se mL(-1) for selenoprotein P and 11 ± 4 ng Se mL(-1) for selenoalbumin. These values are found to be in close agreement with published values for a limited number of healthy volunteer samples, and to establish baseline Se levels in serum proteins for an apparently healthy group of individuals, thus allowing for subsequent comparisons with respective values determined for groups of individuals with selenium related health issues, as well as assist in the discovery of potential selenium biomarkers. Also, the relationship between Se serum protein levels and some anthropometric characteristics of the volunteer population were investigated. Additionally, further development of the analytical method used in this study was achieved by adding a size exclusion chromatography column after the two affinity columns via a switching valve. This allowed for the separation of small selenium-containing molecules from glutathione peroxidase and thus enhanced the overall confidence in its identification.

A diagnostic model based on acylcarnitines has the potential to predict the presence and stage of endometriosis.

The epidemiology of selenium (Se) is mainly based on the determination of total serum selenium levels (TSe) which by many aspects is an inadequate marker of Se status. In this study we applied a recently developed LC-ICP-MS method, for the determination of the selenium content of the three main serum selenium-containing proteins, in a subcohort of the ATTICA study. This enables us to investigate whether the selenium distribution to selenoproteins may correlate with demographic (age, gender) and lifestyle variables (smoking, physical activity) that are crucial for the development of chronic diseases. A sub-sample from the ATTICA Study, consisted of 236 males (40 ± 11 years) and 163 females (38 ± 12 years), was selected. The selenium content of glutathione peroxidase (GPx-3), selenoprotein P (SelP) and selenoalbumin (SeAlb) was determined in serum by LC-ICP/MS method. We found that 26% of TSe is found in GPx-3, 61% in SelP and 13% in SeAlb. We have assessed the different ratios of selenoproteins' selenium content (Se-GPX-3/Se-SelP, Se-GPX-3/Se-SeAlb, Se-SelP/Se-SeAlb), showing that people with similar TSe may have different distribution of this selenium to selenoproteins. Total selenium levels and gender are the variables that mostly affect selenium distribution to selenoproteins while age, smoking, physical activity and BMI do not significantly influence selenium distribution. In conclusion, the simultaneous determination of the selenium content of serum selenium-containing selenoproteins is necessary for a thorough estimation of selenium status. The ratio of the Se content between selenoproteins may be proven a novel, valid marker of selenium status.