Gene expression profiling of resting and activated vascular smooth muscle cells by serial analysis of gene expression and clustering analysis

Migration and proliferation of vascular smooth muscle cells (SMCs) are key events in atherosclerosis. However, little is known about alterations in gene expression upon transition of the quiescent, contractile SMC to the proliferative SMC. We performed serial analysis of gene expression (SAGE) of cultured, human SMCs, either grown under resting circumstances or activated with an atherogenic stimulus. Analysis of tags, representing 47,209 and 47,259 mRNAs from a library of resting and activated SMCs, respectively, identified 105 tags induced and 52 tags repressed greater than fivefold. To evaluate the relevance in SMC biology of unmatched, regulated tags, we performed hierarchical clustering analysis, based on their expression profiles in public SAGE databases, and clustered these novel genes in distinct groups. The regulation in SMCs was confirmed by Northern blotting for representative genes of these groups. Plasminogen activator inhibitor-2 has not been associated with atherosclerosis before and was localized to atherosclerotic lesions.     

Complete genome sequence of Ferroglobus placidus AEDII12DO

Ferroglobus placidus belongs to the order Archaeoglobales within the archaeal phylum Euryarchaeota. Strain AEDII12DO is the type strain of the species and was isolated from a shallow marine hydrothermal system at Vulcano, Italy. It is a hyperthermophilic, anaerobic chemolithoautotroph, but it can also use a variety of aromatic compounds as electron donors. Here we describe the features of this organism together with the complete genome sequence and annotation. The 2,196,266 bp genome with its 2,567 protein-coding and 55 RNA genes was sequenced as part of a DOE Joint Genome Institute Laboratory Sequencing Program (LSP) project.     

Adiponectin and negative mood in healthy premenopausal and postmenopausal women

Negative mood and stress are associated with cardiovascular and metabolic disease. There are likely many physiological mechanisms underlying the poor health outcomes. The relationship of psychological states (negative mood, life stress, and stress-responsive hormones) and adiponectin, an adipokine that promotes insulin sensitivity, was investigated in two separate studies. The two groups of participants included 52 healthy, premenopausal women, and 63 postmenopausal women with a range of stress levels. The relationship between adiponectin and psychological state (perceived stress and negative mood) was examined cross-sectionally in both groups of participants, but also prospectively (1 year later) in the group of postmenopausal women.In premenopausal women, negative mood and nocturnal urinary epinephrine were significantly related to adiponectin, independent of BMI. In postmenopausal women, negative mood was not associated with adiponectin cross-sectionally, but negative mood was a significant predictor for lower levels of adiponectin 1 year later, independent of initial adiponectin concentrations and changes in body mass index. Lastly, having a depressive disorder was related to lower adiponectin. As adiponectin levels are associated with insulin resistance, obesity, and diabetes mellitus, these findings suggest there may be an adiponectin-mediated pathway explaining in part how negative mood affects metabolic health. Mechanistic studies are needed to explore this potential relationship further.     

Primary prevention of gestational diabetes mellitus and large-for-gestational-age newborns by lifestyle counseling: a cluster-randomized controlled trial

Background

Our objective was to examine whether gestational diabetes mellitus (GDM) or newborns'' high birthweight can be prevented by lifestyle counseling in pregnant women at high risk of GDM.

Method and Findings

We conducted a cluster-randomized trial, the NELLI study, in 14 municipalities in Finland, where 2,271 women were screened by oral glucose tolerance test (OGTT) at 8–12 wk gestation. Euglycemic (n = 399) women with at least one GDM risk factor (body mass index [BMI] ≥25 kg/m², glucose intolerance or newborn''s macrosomia (≥4,500 g) in any earlier pregnancy, family history of diabetes, age ≥40 y) were included. The intervention included individual intensified counseling on physical activity and diet and weight gain at five antenatal visits. Primary outcomes were incidence of GDM as assessed by OGTT (maternal outcome) and newborns'' birthweight adjusted for gestational age (neonatal outcome). Secondary outcomes were maternal weight gain and the need for insulin treatment during pregnancy. Adherence to the intervention was evaluated on the basis of changes in physical activity (weekly metabolic equivalent task (MET) minutes) and diet (intake of total fat, saturated and polyunsaturated fatty acids, saccharose, and fiber). Multilevel analyses took into account cluster, maternity clinic, and nurse level influences in addition to age, education, parity, and prepregnancy BMI. 15.8% (34/216) of women in the intervention group and 12.4% (22/179) in the usual care group developed GDM (absolute effect size 1.36, 95% confidence interval [CI] 0.71–2.62, p = 0.36). Neonatal birthweight was lower in the intervention than in the usual care group (absolute effect size −133 g, 95% CI −231 to −35, p = 0.008) as was proportion of large-for-gestational-age (LGA) newborns (26/216, 12.1% versus 34/179, 19.7%, p = 0.042). Women in the intervention group increased their intake of dietary fiber (adjusted coefficient 1.83, 95% CI 0.30–3.25, p = 0.023) and polyunsaturated fatty acids (adjusted coefficient 0.37, 95% CI 0.16–0.57, p<0.001), decreased their intake of saturated fatty acids (adjusted coefficient −0.63, 95% CI −1.12 to −0.15, p = 0.01) and intake of saccharose (adjusted coefficient −0.83, 95% CI −1.55 to −0.11, p  =  0.023), and had a tendency to a smaller decrease in MET minutes/week for at least moderate intensity activity (adjusted coefficient 91, 95% CI −37 to 219, p = 0.17) than women in the usual care group. In subgroup analysis, adherent women in the intervention group (n = 55/229) had decreased risk of GDM (27.3% versus 33.0%, p = 0.43) and LGA newborns (7.3% versus 19.5%, p = 0.03) compared to women in the usual care group.

Conclusions

The intervention was effective in controlling birthweight of the newborns, but failed to have an effect on maternal GDM.

Trial registration

Current Controlled Trials ISRCTN33885819 Please see later in the article for the Editors'' Summary     

Detection and quantification of probiotic strain Lactobacillus gasseri K7 in faecal samples by targeting bacteriocin genes

Lactobacillus gasseri K7 is a probiotic strain that produces bacteriocins gassericin K7 A and K7 B. In order to develop a real-time quantitative PCR assay for the detection of L. gasseri K7, 18 reference strains of the Lactobacillus acidophilus group and 45 faecal samples of adults who have never consumed strain K7 were tested with PCR using 14 pairs of primers specific for gassericin K7 A and K7 B gene determinants. Incomplete gassericin K7 A or K7 B gene clusters were found to be dispersed in different lactobacilli strains as well as in faecal microbiota. One pair of primers was found to be specific for the total gene cluster of gassericin K7A and one for gassericin K7B. The real-time PCR analysis of faecal samples spiked with K7 strain revealed that primers specific for the gene cluster of the gassericin K7 A were more suitable for quantitative determination than those for gassericin K7 B, due to the lower detection level. Targeting of the gassericin K7 A or K7 B gene cluster with specific primers could be used for detection and quantification of L. gasseri K7 in human faecal samples without prior cultivation. The results of this study also present new insights into the prevalence of bacteriocin-encoding genes in gastrointestinal tract.     

Structure and mechanism of the ThDP-dependent benzaldehyde lyase from Pseudomonas fluorescens

Pseudomonas fluorescens is able to grow on R-benzoin as the sole carbon and energy source because it harbours the enzyme benzaldehyde lyase that cleaves the acyloin linkage using thiamine diphosphate (ThDP) as a cofactor. In the reverse reaction, this lyase catalyses the carboligation of two aldehydes with high substrate and stereospecificity. The enzyme structure was determined by X-ray diffraction at 2.6 A resolution. A structure-based comparison with other proteins showed that benzaldehyde lyase belongs to a group of closely related ThDP-dependent enzymes. The ThDP cofactors of these enzymes are fixed at their two ends in separate domains, suspending a comparatively mobile thiazolium ring between them. While the residues binding the two ends of ThDP are well conserved, the lining of the active centre pocket around the thiazolium moiety varies greatly within the group. Accounting for the known reaction chemistry, the natural substrate R-benzoin was modelled unambiguously into the active centre of the reported benzaldehyde lyase. Due to its substrate spectrum and stereospecificity, the enzyme extends the synthetic potential for carboligations appreciably.     

Mammals have two twinfilin isoforms whose subcellular localizations and tissue distributions are differentially regulated

Twinfilin is a highly conserved actin monomer-binding protein that regulates cytoskeletal dynamics in organisms from yeast to mammals. In addition to the previously characterized mammalian twinfilin-1, a second protein with approximately 65% sequence identity to twinfilin-1 exists in mouse and humans. However, previous studies failed to identify any actin binding activity in this protein (Rohwer, A., Kittstein, W., Marks, F., and Gschwendt, M. (1999) Eur. J. Biochem. 263, 518-525). Here we show that this protein, which we named twinfilin-2, is indeed an actin monomer-binding protein. Similar to twinfilin-1, mouse twinfilin-2 binds ADP-G-actin with a higher affinity (KD = 0.12 microM) than ATP-G-actin (KD = 1.96 microM) and efficiently inhibits actin filament assembly in vitro. Both mouse twinfilins inhibit the nucleotide exchange on actin monomers and directly interact with capping protein. Furthermore, the actin interactions of mouse twinfilin-1 and twinfilin-2 are inhibited by phosphatidylinositol (4,5)-bisphosphate. Although biochemically very similar, our Northern blots and in situ hybridizations show that these two proteins display distinct expression patterns. Twinfilin-1 is the major isoform in embryos and in most adult mouse non-muscle cell-types, whereas twinfilin-2 is the predominant isoform of adult heart and skeletal muscles. Studies with isoform-specific antibodies demonstrated that although the two proteins show similar localizations in unstimulated cells, they are regulated by different mechanisms. The small GTPases Rac1 and Cdc42 induce the redistribution of twinfilin-1 to membrane ruffles and cell-cell contacts, respectively, but do not affect the localization of twinfilin-2. Taken together, these data show that mammals have two twinfilin isoforms, which are differentially expressed and regulated through distinct cellular signaling pathways.     

Functional composition of plant communities determines the spatial and temporal stability of soil microbial properties in a long‐term plant diversity experiment

Stable provisioning of ecosystem functions and services is crucial for human well‐being in a changing world. Two essential ecological components driving vital ecosystem functions in terrestrial ecosystems are plant diversity and soil microorganisms. In this study, we tracked soil microbial basal respiration and biomass over a time period of 12 years in a grassland biodiversity experiment (the Jena Experiment) and examined the role of plant diversity and plant functional group composition for the spatial and temporal stability of soil microbial properties (basal respiration and biomass) in bulk‐soil. Spatial and temporal stability were calculated as the inverse coefficient of variation (CV^?1) of soil microbial respiration and biomass measured from soil samples taken over space and time, respectively. We found that 1) plant species richness consistently increased soil microbial properties after a time lag of four years since the establishment of the experimental plots, 2) plant species richness had minor effects on the spatial stability of soil microbial properties, whereas 3) the functional composition of plant communities significantly affected spatial stability of soil microbial properties, with legumes and tall herbs reducing both the spatial stability of microbial respiration and biomass, while grasses increased the latter, and 4) the effect of plant diversity on temporal stability of soil microbial properties turned from being negative to neutral, suggesting that the recovery of soil microbial communities from former arable land‐use takes more than a decade. Our results highlight the importance of plant functional group composition for the spatial and temporal stability of soil microbial properties, and hence for microbially‐driven ecosystem processes, such as decomposition and element cycling, in temperate semi‐natural grassland.