ObjectiveOmega-3 fatty acids, particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), likely prevent cardiovascular disease, however their mechanisms remain unclear. Recently, the role of DNA damage in atherogenesis has been receiving considerable attention. Here, we investigated the effects of EPA and DHA on DNA damage in vascular endothelial cells to clarify their antiatherogenic mechanisms.Methods and resultsWe determined the effect of EPA and DHA on H2O2-induced DNA damage response in human aortic endothelial cells. Immunofluorescence staining showed that γ-H2AX foci formation, a prominent marker of DNA damage, was significantly reduced in the cells treated with EPA and DHA (by 47% and 48%, respectively). H2O2-induced activation of ATM, a major kinase orchestrating DNA damage response, was significantly reduced with EPA and DHA treatment (by 31% and 33%, respectively). These results indicated EPA and DHA attenuated DNA damage independently of the DNA damage response. Thus the effects of EPA and DHA on a source of DNA damage were examined. EPA and DHA significantly reduced intracellular reactive oxygen species under both basal condition and H2O2 stimulation. In addition, the mRNA levels of antioxidant molecules, such as heme oxygenase-1, thioredoxin reductase 1, ferritin light chain, ferritin heavy chain and manganese superoxide dismutase, were significantly increased with EPA and DHA. Silencing nuclear factor erythroid 2-related factor 2 (NRF2) remarkably abrogated the increases in mRNA levels of antioxidant molecules and the decrease in intracellular reactive oxygen species. Furthermore, EPA and DHA significantly reduced H2O2-induced senescence-associated β-galactosidase activity in the cells (by 31% and 22%, respectively), which was revoked by NRF2 silencing.ConclusionsOur results suggested that EPA and DHA attenuate oxidative stress-induced DNA damage in vascular endothelial cells through upregulation of NRF2-mediated antioxidant response. Therefore omega-3 fatty acids likely help prevent cardiovascular disease, at least in part, by their genome protective properties.

Corals evolved by establishing symbiotic relationships with various microorganisms (the zooxanthellae, filamentous algae, cyanobacteria, bacteria, archaea, fungi and viruses), forming the ‘coral holobiont'. Among them, the endolithic community is the least studied. Its main function was considered to be translocation of photo-assimilates to the coral host, particularly during bleaching. Here, we hypothesize that (i) endolithic algae may show similar primary production rates in healthy or bleached corals by changing their pigment ratios, and therefore that similar production and translocation of organic matter may occur at both conditions and (ii) diazotrophs are components of the endolithic community; therefore, N2 fixation and translocation of organic nitrogen may occur. We tested these hypotheses in incubation of Porites lutea with 13C and 15N tracers to measure primary production and N2 fixation in coral tissues and endoliths. Assimilation of the 13C atom (%) was observed in healthy and bleached corals when the tracer was injected in the endolithic band, showing translocation in both conditions. N2 fixation was found in coral tissues and endolithic communities with translocation of organic nitrogen. Thus, the endolithic community plays an important role in supporting the C and N metabolism of the holobiont, which may be crucial under changing environmental conditions.

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The aim of the study was to assess the clinical features of Q fever pneumonia in Japan. Four cases of Q fever pneumonia (a female aged 21 and males aged 53, 74 and 87 years) who were diagnosed using the PanBio ELISA test kit, were assessed and their clinical features are described. The frequency of Q fever pneumonia among our cases of community-acquired pneumonia was 1.4% (4/284). A 21-year-old female had a typical case of the disease with (i) a history of owning a cat, (ii) onset with fever and dry cough, (iii) multiple soft infiltrative shadows on CXR, (iv) a normal white blood cell count, and (v) good response to clarithromycin. The pneumonias in the other three cases were considered mixed infections with bacteria such as Streptococcus pneumoniae and Haemophilus influenzae. Their clinical features included the following: (i) an elderly person with an underlying disease, (ii) onset with fever and purulent sputum, (iii) coarse crackles on auscultation, (iv) infiltrative shadows and pleural effusion on CXR, (v) increased white blood cells with elevated BUN and hyponatraemia, and (vi) modest responses to combined therapy with carbapenem and minocycline. Our observations suggest that two types of pneumonia caused by Coxiella burnetti exist; one with the usual features of atypical pneumonia, and the other presenting with the clinical features of bacterial pneumonia in the elderly due to mixed bacterial infection.