Biogeochemistry and geomicrobiology of cold-water coral carbonate mounds - lessons learned from IODP Expedition 307

Large mound structures associated with cold-water coral ecosystems commonly occur on the slopes of continental margins, for instance, west of Ireland in the Porcupine Seabight, the Gulf of Cadiz or the Straits of Florida. In the Porcupine Seabight over 1500 mounds of up to 5 km in diameter and 250 m height lie at water depths of 600 to 900 m. The cold-water coral reef ecosystems associated with these structures are considered to be “hotspots” of organic carbon mineralization and microbial systems. To establish a depositional and biogeochemical/diagenetic model for cold-water carbonate mounds, Challenger Mound and adjacent continental slope sites were drilled in May 2005 during IODP Expedition 307. One major objective was to test whether deep sub-surface hydrocarbon flow and enhanced microbial activity within the mound structure was important in producing and stabilizing these sedimentary structures.Drilling results showed that the Challenger mound succession (IODP Site U1317) is 130 to 150 meters thick, and mainly consists of floatstone and rudstone facies formed of fine sediments and cold-water branching corals. Pronounced recurring cycles on the scales of several meters are recognized in carbonate content (up to 70% carbonate) and color reflectance, and are probably associated with Pleistocene glacial-interglacial cycles. A role for methane seepage and subsequent anaerobic oxidation was discounted both as a hard-round substrate for mound initiation and as a principal source of carbonate within the mound succession. A broad sulfate-methane transition (approximately 50 m thick) within the Miocene sediments suggested that the zone of anaerobic oxidation of methane principally occurs below the moundbase. In the mound sediments, interstitial water profiles of sulfate, alkalinity, Mg, and Sr suggested a tight coupling between carbonate diagenesis and low rates of microbial sulfate reduction. Overall organic carbon mineralization within cold-water coral mound appeared to be dominated by low rates of iron- and sulfate-reduction that occur in discrete layers within the mound. This was consistent with distributions of total cell-counts, acetate turnover (Webster et al. 2009) and hydrogenase activity (Soffiento et al. 2009). However, biomarker lipid distributions suggested that the Miocene sediments underlying the mound, into which sulfate is diffusing, as well as the sediments from the non-cold water coral reference site (U1318) contain higher abundances of living microbes. The results obtained from Expedition 307 are consistent with a picture emerging from other biogeochemical studies of cold-water coral mound and reef sites. Unless impacted by some external forcing (e.g. fluid flow or erosion event), the microbial activity in the underlying cold-water coral mound sediments is largely decoupled from the highly diverse, active surface ecosystem

Identification of RNA bound to the TDP-43 ribonucleoprotein complex in the adult mouse brain

Cytoplasmic inclusions containing TDP-43 are a pathological hallmark of several neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS) and frontotemporal dementia. TDP-43 is an RNA binding protein involved in gene regulation through control of RNA transcription, splicing and transport. However, the function of TDP-43 in the nervous system is largely unknown and its role in the pathogenesis of ALS is unclear. The aim of this study was to identify genes in the central nervous system that are regulated by TDP-43. RNA-immunoprecipitation with anti-TDP-43 antibody, followed by microarray analysis (RIP-chip), was used to isolate and identify RNA bound to TDP-43 protein from mouse brain. This analysis produced a list of 1839 potential TDP-43 gene targets, many of which overlap with previous studies and whose functions include RNA processing and synaptic function. Immunohistochemistry demonstrated that the TDP-43 protein could be found at the presynaptic membrane of axon terminals in the neuromuscular junction in mice. In conclusion, the finding that TDP-43 binds to RNA that codes for genes related to synaptic function, together with the localization of TDP-43 protein at axon terminals, suggests a role for TDP-43 in the transport of synaptic mRNAs into distal processes

Estrogen inhibits GH signaling by suppressing GH-induced JAK2 phosphorylation, an effect mediated by SOCS-2

Oral estrogen administration attenuates the metabolic action of growth hormone (GH) in humans. To investigate the mechanism involved, we studied the effects of estrogen on GH signaling through Janus kinase (JAK)2 and the signal transducers and activators of transcription (STATs) in HEK293 cells stably expressing the GH receptor (293GHR), HuH7 (hepatoma) and T-47D (breast cancer) cells. 293GHR cells were transiently transfected with an estrogen receptor-α expression plasmid and luciferase reporters with binding elements for STAT3 and STAT5 or the β-casein promoter. GH stimulated the reporter activities by four- to sixfold. Cotreatment with 17β-estradiol (E2) resulted in a dose-dependent reduction in the response of all three reporters to GH to a maximum of 49-66% of control at 100 nM (P < 0.05). No reduction was seen when E2 was added 1-2 h after GH treatment. Similar inhibitory effects were observed in HuH7 and T-47D cells. E2 suppressed GH-induced JAK2 phosphorylation, an effect attenuated by actinomycin D, suggesting a requirement for gene expression. Next, we investigated the role of the suppressors of cytokine signaling (SOCS) in E2 inhibition. E2 increased the mRNA abundance of SOCS-2 but not SOCS-1 and SOCS-3 in HEK293 cells. The inhibitory effect of E2 was absent in cells lacking SOCS-2 but not in those lacking SOCS-1 and SOCS-3. In conclusion, estrogen inhibits GH signaling, an action mediated by SOCS-2. This paper provides evidence for regulatory interaction between a sex steroid and the GH/JAK/STAT pathway, in which SOCS-2 plays a central mechanistic role

MenaQ7 (R) and maintenance of the elastic properties of the arteries: evaluation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006

Peer reviewedPublisher PD

The bacteriohopanepolyol inventory of novel aerobic methane oxidising bacteria reveals new biomarker signatures of aerobic methanotrophy in marine systems

Aerobic methane oxidation (AMO) is one of the primary biologic pathways regulating the amount of methane (CH4) released into the environment. AMO acts as a sink of CH4, converting it into carbon dioxide before it reaches the atmosphere. It is of interest for (paleo)climate and carbon cycling studies to identify lipid biomarkers that can be used to trace AMO events, especially at times when the role of methane in the carbon cycle was more pronounced than today. AMO bacteria are known to synthesise bacteriohopanepolyol (BHP) lipids. Preliminary evidence pointed towards 35-aminobacteriohopane-30,31,32,33,34-pentol (aminopentol) being a characteristic biomarker for Type I methanotrophs. Here, the BHP compositions were examined for species of the recently described novel Type I methanotroph bacterial genera Methylomarinum and Methylomarinovum, as well as for a novel species of a Type I Methylomicrobium. Aminopentol was the most abundant BHP only in Methylomarinovum caldicuralii, while Methylomicrobium did not produce aminopentol at all. In addition to the expected regular aminotriol and aminotetrol BHPs, novel structures tentatively identified as methylcarbamate lipids related to C-35 amino-BHPs (MCBHPs) were found to be synthesised in significant amounts by some AMO cultures. Subsequently, sediments and authigenic carbonates from methane-influenced marine environments were analysed. Most samples also did not contain significant amounts of aminopentol, indicating that aminopentol is not a useful biomarker for marine aerobic methanotophic bacteria. However, the BHP composition of the marine samples do point toward the novel MC-BHPs components being potential new biomarkers for AMO

Joselito® and lowering of LDL-cholesterol concentration, blood pressure, and reduction of coronary heart disease risk: Evaluation of a health claim pursuant to Article 14 of Regulation (EC) No 1924/2006

Following an application from C &amp; aacute;rnicas Joselito S.A. pursuant to Article 14 of Regulation (EC) No 1924/2006 via the Competent Authority of Spain, the Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on the scientific substantiation of a health claim related to 'Joselito ham increases antioxidant substances in the body, reduces blood pressure and plasma triglycerides, decreases oxidative stress and prevents effect in diseases related to the cardiovascular and intestinal systems'. The scope of the application was proposed to fall under a health claim referring to disease risk reduction. The food constituent that is the subject of the health claim is Joselito, an Iberian ham characterised by a high content of oleic acid. The Panel considers that the food is sufficiently characterised. The Panel considers that lowering of LDL-cholesterol concentration and blood pressure is a beneficial effect by decreasing the risk of coronary heart disease. Upon a request from EFSA, the applicant identified one human intervention study as being pertinent to the claim. However, due to methodological limitations, the Panel considers that no conclusions can be drawn from this study for the scientific substantiation of the claim. The Panel notes that no human intervention studies from which conclusions could be drawn for the scientific substantiation of the claim were provided by the applicant. The Panel concludes that a cause and effect relationship has not been established between the intake of Joselito (R) ham and the reduction of LDL-cholesterol concentration or blood pressure

Appethyl® and reduction of body weight: evaluation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006

Following an application from Greenleaf Medical AB, submitted for authorisation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006 via the Competent Authority of Sweden, the EFSA Panel on Nutrition, Novel Foods and Food allergens (NDA) was asked to deliver an opinion on the scientific substantiation of a health claim related to Appethyl® and reduction of body weight. Appethyl® is an aqueous extract from spinach leaves standardised by the manufacturing process and its lipase/colipase inhibition capacity in vitro. The Panel considers that the food is sufficiently characterised. A reduction in body weight is a beneficial physiological effect for overweight/obese individuals. The applicant identified a total of three human intervention studies that investigated the effects of Appethyl® on body weight as being pertinent to the claim. In weighing the evidence, the Panel took into account that Appethyl® (5 g/day for 12 weeks) had no effect on body weight as compared to placebo under minimal dietary counselling and moderate physical activity, and that no beneficial physiological effects are to be expected for the target population of overweight/obese individuals from the weight loss that could be attributed to the intervention with Appethyl® under predefined energy restriction and moderate physical activity. The Panel also considered that the effect of Appethyl® (5 g/day for 24 weeks) on body weight maintenance after initial weight loss shown in one study has not been replicated in different settings, which questions the external validity of the results, and that no evidence was provided for a plausible mechanism by which daily consumption of Appethyl® could exert a sustained effect on body weight in humans. The Panel concludes that a cause-and-effect relationship has not been established between the consumption of Appethyl® and a reduction of body weight under the conditions of use proposed by the applicant

‘Citicoline’ and support of the memory function: Evaluation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006

Following an application from Egde Pharma Sp. z o.o, submitted for authorisation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006 via the Competent Authority of Poland, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on the scientific substantiation of a health claim related to citicoline and memory. The Panel considers that the food, citicoline (cytidine 5-diphosphocholine, CDP-Choline) inner salt, is sufficiently characterised. Improvement, maintenance or reduced loss of memory is a beneficial physiological effect for middle-aged or elderly adults encountering age-associated subjective memory impairment. The applicant identified three pertinent human intervention studies in healthy individuals that investigated the effect of citicoline on memory. In weighing the evidence, the Panel took into account that only one randomised controlled trial in healthy participants showed a beneficial effect of citicoline on episodic memory when consumed at doses of 500 mg/day for 12 weeks, whereas this effect has not been observed in another study using citicoline at doses of 1 g/day for 3 months or supported by data obtained in patients with dementia using doses of 1 g/day for 12 weeks and 12 months. No convincing evidence of a plausible mechanism by which citicoline or any of its components (in addition to their endogenous synthesis) could exert an effect on memory in humans has been provided. The Panel concludes that a cause-and-effect relationship has not been established between the consumption of citicoline (CDP-Choline) inner salt and improvement, maintenance or reduced loss of memory in middle-aged or elderly adults encountering age-associated subjective memory impairment

Choline and contribution to normal liver function of the foetus and exclusively breastfed infants: evaluation of a health claim pursuant to Article 14 of Regulation (EC) No 1924/2006

Following an application from Procter &amp; Gamble BV pursuant to Article 14 of Regulation (EC) No 1924/2006 via the Competent Authority of Belgium, the Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on the scientific substantiation of a health claim related to choline and contribution to normal liver function of the foetus and exclusively breastfed infant. The scope of the application was proposed to fall under a health claim referring to children's development and health. The Panel considers that choline is sufficiently characterised. The claimed effect proposed by the applicant is contribution ‘to normal foetal and infant development, especially liver’. The proposed target population is ‘unborn fetuses and breastfed infants’. Choline is involved in the structure of cell membranes, cell signalling, metabolism and transport of lipids and cholesterol and neurotransmitter synthesis. Although choline can be synthesised de novo by the human body, depletion-repletion studies in humans show that low choline intake leads to liver dysfunction and muscle damage, which are reverted by the administration of dietary choline. For these functions, de novo synthesis of choline by the human body is insufficient and choline must be obtained from dietary sources. No human studies have addressed the effect of low maternal dietary choline intake on liver function in the fetus or exclusively breastfed infants. However, the Panel considers that the biological role of choline in normal liver function and dietary choline being essential for the function applies to all ages, including fetus and infants. The Panel concludes that a cause and effect relationship has been established between the intake of choline by pregnant and lactating women and contribution to normal liver function of the fetus and exclusively breastfed infants

Scientific Opinion on additional scientific data related to the safety of preparations of Rheum palmatum L., Rheum officinale Baill. and their hybrids, Rhamnus purshiana DC., Rhamnus frangula L. and Cassia senna L., submitted pursuant to Article 8(4) of Regulation (EC) No 1925/2006

The Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver a scientific opinion on the safety of plant preparations from the root or rhizome of Rheum palmatum L., Rheum officinale Baill. and their hybrids, from the bark of Rhamnus frangula L. and Rhamnus purshiana DC. and from the leaf or fruit of Cassia senna L., which have been placed under Union scrutiny in Part C of Annex III in accordance with Article 8(4) of Regulation (EC) No 1925/2006. The NDA Panel reviewed the additional scientific data submitted during the period of scrutiny and the public consultation by interested parties. The pertinent scientific data were in&nbsp;vitro and in&nbsp;vivo genotoxicity studies on the plant preparations under consideration. All the results of the genotoxicity studies on plant preparations were negative. However, the plant preparations that were tested in the submitted studies were not sufficiently characterised with respect to the content of total and individual hydroxyanthracene derivatives (HADs) and components other than HADs. The studies confirmed the presence of ■■■■■, known to be genotoxic in&nbsp;vivo, and ■■■■■, shown to be genotoxic in&nbsp;vitro. In line with the EFSA Scientific Committee statement on genotoxicity assessment of chemical mixtures, considering the presence of an in&nbsp;vivo genotoxic compound, the plant preparations used in these studies have to be considered of concern for genotoxicity. Thus, the safety of preparations containing HADs from the root or rhizome of Rheum palmatum L., Rheum officinale Baill. and their hybrids, from the leaf or fruit of Cassia senna L. and from the bark of Rhamnus frangula L. and Rhamnus purshiana DC. cannot be established based on the submitted studies