OCT4 activates a Suv39h1-repressive antisense lncRNA to couple histone H3 Lysine 9 methylation to pluripotency.

Histone H3 Lysine 9 (H3K9) methylation, a characteristic mark of heterochromatin, is progressively implemented during development to contribute to cell fate restriction as differentiation proceeds. Accordingly, in undifferentiated and pluripotent mouse Embryonic Stem (ES) cells the global levels of H3K9 methylation are rather low and increase only upon differentiation. How global H3K9 methylation levels are coupled with the loss of pluripotency remains largely unknown. Here, we identify SUV39H1, a major H3K9 di- and tri-methylase, as an indirect target of the pluripotency network of Transcription Factors (TFs). We find that pluripotency TFs, principally OCT4, activate the expression of Suv39h1as, an antisense long non-coding RNA to Suv39h1. In turn, Suv39h1as downregulates Suv39h1 transcription in cis via a mechanism involving the modulation of the chromatin status of the locus. The targeted deletion of the Suv39h1as promoter region triggers increased SUV39H1 expression and H3K9me2 and H3K9me3 levels, affecting all heterochromatic regions, particularly peri-centromeric major satellites and retrotransposons. This increase in heterochromatinization efficiency leads to accelerated and more efficient commitment into differentiation. We report, therefore, a simple genetic circuitry coupling the genetic control of pluripotency with the global efficiency of H3K9 methylation associated with a major cell fate restriction, the irreversible loss of pluripotency.

OCT4 induces embryonic pluripotency via STAT3 signaling and metabolic mechanisms.

OCT4 is a fundamental component of the molecular circuitry governing pluripotency in vivo and in vitro. To determine how OCT4 establishes and protects the pluripotent lineage in the embryo, we used comparative single-cell transcriptomics and quantitative immunofluorescence on control and OCT4 null blastocyst inner cell masses at two developmental stages. Surprisingly, activation of most pluripotency-associated transcription factors in the early mouse embryo occurs independently of OCT4, with the exception of the JAK/STAT signaling machinery. Concurrently, OCT4 null inner cell masses ectopically activate a subset of trophectoderm-associated genes. Inspection of metabolic pathways implicates the regulation of rate-limiting glycolytic enzymes by OCT4, consistent with a role in sustaining glycolysis. Furthermore, up-regulation of the lysosomal pathway was specifically detected in OCT4 null embryos. This finding implicates a requirement for OCT4 in the production of normal trophectoderm. Collectively, our findings uncover regulation of cellular metabolism and biophysical properties as mechanisms by which OCT4 instructs pluripotency.

The significance of WRKY45 transcription factor in metabolic adjustments during dark-induced leaf senescence.

Plants are constantly exposed to environmental changes that affect their performance. Metabolic adjustments are crucial to controlling energy homoeostasis and plant survival, particularly during stress. Under carbon starvation, coordinated reprogramming is initiated to adjust metabolic processes, which culminate in premature senescence. Notwithstanding, the regulatory networks that modulate transcriptional control during low energy remain poorly understood. Here, we show that the WRKY45 transcription factor is highly induced during both developmental and dark-induced senescence. The overexpression of Arabidopsis WRKY45 resulted in an early senescence phenotype characterized by a reduction of maximum photochemical efficiency of photosystem II and chlorophyll levels in the later stages of darkness. The detailed metabolic characterization showed significant changes in amino acids coupled with the accumulation of organic acids in WRKY45 overexpression lines during dark-induced senescence. Furthermore, the markedly upregulation of alternative oxidase (AOX1a, AOX1d) and electron transfer flavoprotein/ubiquinone oxidoreductase (ETFQO) genes suggested that WRKY45 is associated with a dysregulation of mitochondrial signalling and the activation of alternative respiration rather than amino acids catabolism regulation. Collectively our results provided evidence that WRKY45 is involved in the plant metabolic reprogramming following carbon starvation and highlight the potential role of WRKY45 in the modulation of mitochondrial signalling pathways.

MYC integrates FSH signalling networks in cumulus cells during bovine oocyte maturation.

Follicle-stimulating hormone (FSH) contributes to the acquisition of oocyte competence by modulating signalling pathways in cumulus cells (CCs), albeit much less is known about transcription factors (TFs) that orchestrate the downstream transcriptional changes. This work allowed to prospect TFs involved in FSH-mediated signalling during oocyte in vitro maturation (IVM). Bovine cumulus-oocyte complexes underwent IVM with FSH (FSH+) or without FSH (control/CTL) for 22 h, and CCs were subjected to gene expression profiling. Five software identified reference genes for RT-qPCR (ATP1A1, UBB, and YWHAZ). The transcript levels of FSH-responsive genes HAS2 and PTGS2 (COX2) validated the experimental design. Among candidate TFs, MYC was down-regulated (0.35-fold; P < 0.0001), and THAP11 (RONIN) was up-regulated (1.47-fold; P = 0.016) under FSH+ conditions. In silico analyses predicted binding motifs at MYC and THAP11 genes for previously known FSH-responsive TFs. Signalling pathways (EGFR, ERK, GSK3, PKA, and P38) may execute post-translational regulation due to potential phosphorylation sites in MYC and THAP11 proteins. Prediction of protein-protein interaction networks showed MYC as a core component of FSH signalling, albeit THAP11 acts independently. Hence, MYC integrates FSH signalling networks and may assist in exploring genome-wide transcriptional changes associated with the acquisition of oocyte competence.

Evolutionary dynamics of bipartite begomoviruses revealed by complete genome analysis.

Several key evolutionary events marked the evolution of geminiviruses, culminating with the emergence of divided (bipartite) genomes represented by viruses classified in the genus Begomovirus. This genus represents the most abundant group of multipartite viruses, contributing significantly to the observed abundance of multipartite species in the virosphere. Although aspects related to virus-host interactions and evolutionary dynamics have been extensively studied, the bipartite nature of these viruses has been little explored in evolutionary studies. Here, we performed a parallel evolutionary analysis of the DNA-A and DNA-B segments of New World begomoviruses. A total of 239 full-length DNA-B sequences obtained in this study, combined with 292 DNA-A and 76 DNA-B sequences retrieved from GenBank, were analysed. The results indicate that the DNA-A and DNA-B respond differentially to evolutionary processes, with the DNA-B being more permissive to variation and more prone to recombination than the DNA-A. Although a clear geographic segregation was observed for both segments, differences in the genetic structure between DNA-A and DNA-B were also observed, with cognate segments belonging to distinct genetic clusters. DNA-B coding regions evolve under the same selection pressures than DNA-A coding regions. Together, our results indicate an interplay between reassortment and recombination acting at different levels across distinct subpopulations and segments.

One-step generation of conditional and reversible gene knockouts.

Loss-of-function studies are key for investigating gene function, and CRISPR technology has made genome editing widely accessible in model organisms and cells. However, conditional gene inactivation in diploid cells is still difficult to achieve. Here, we present CRISPR-FLIP, a strategy that provides an efficient, rapid and scalable method for biallelic conditional gene knockouts in diploid or aneuploid cells, such as pluripotent stem cells, 3D organoids and cell lines, by co-delivery of CRISPR-Cas9 and a universal conditional intronic cassette.

Citrullination regulates pluripotency and histone H1 binding to chromatin.

Citrullination is the post-translational conversion of an arginine residue within a protein to the non-coded amino acid citrulline. This modification leads to the loss of a positive charge and reduction in hydrogen-bonding ability. It is carried out by a small family of tissue-specific vertebrate enzymes called peptidylarginine deiminases (PADIs) and is associated with the development of diverse pathological states such as autoimmunity, cancer, neurodegenerative disorders, prion diseases and thrombosis. Nevertheless, the physiological functions of citrullination remain ill-defined, although citrullination of core histones has been linked to transcriptional regulation and the DNA damage response. PADI4 (also called PAD4 or PADV), the only PADI with a nuclear localization signal, was previously shown to act in myeloid cells where it mediates profound chromatin decondensation during the innate immune response to infection. Here we show that the expression and enzymatic activity of Padi4 are also induced under conditions of ground-state pluripotency and during reprogramming in mouse. Padi4 is part of the pluripotency transcriptional network, binding to regulatory elements of key stem-cell genes and activating their expression. Its inhibition lowers the percentage of pluripotent cells in the early mouse embryo and significantly reduces reprogramming efficiency. Using an unbiased proteomic approach we identify linker histone H1 variants, which are involved in the generation of compact chromatin, as novel PADI4 substrates. Citrullination of a single arginine residue within the DNA-binding site of H1 results in its displacement from chromatin and global chromatin decondensation. Together, these results uncover a role for citrullination in the regulation of pluripotency and provide new mechanistic insights into how citrullination regulates chromatin compaction.

Long-Term Perfusion Culture of Monoclonal Embryonic Stem Cells in 3D Hydrogel Beads for Continuous Optical Analysis of Differentiation.

Developmental cell biology requires technologies in which the fate of single cells is followed over extended time periods, to monitor and understand the processes of self-renewal, differentiation, and reprogramming. A workflow is presented, in which single cells are encapsulated into droplets (Ø: 80 µm, volume: ≈270 pL) and the droplet compartment is later converted to a hydrogel bead. After on-chip de-emulsification by electrocoalescence, these 3D scaffolds are subsequently arrayed on a chip for long-term perfusion culture to facilitate continuous cell imaging over 68 h. Here, the response of murine embryonic stem cells to different growth media, 2i and N2B27, is studied, showing that the exit from pluripotency can be monitored by fluorescence time-lapse microscopy, by immunostaining and by reverse-transcription and quantitative PCR (RT-qPCR). The defined 3D environment emulates the natural context of cell growth (e.g., in tissue) and enables the study of cell development in various matrices. The large scale of cell cultivation (in 2000 beads in parallel) may reveal infrequent events that remain undetected in lower throughput or ensemble studies. This platform will help to gain qualitative and quantitative mechanistic insight into the role of external factors on cell behavior.

NANOG-dependent function of TET1 and TET2 in establishment of pluripotency.

Molecular control of the pluripotent state is thought to reside in a core circuitry of master transcription factors including the homeodomain-containing protein NANOG, which has an essential role in establishing ground state pluripotency during somatic cell reprogramming. Whereas the genomic occupancy of NANOG has been extensively investigated, comparatively little is known about NANOG-associated proteins and their contribution to the NANOG-mediated reprogramming process. Using enhanced purification techniques and a stringent computational algorithm, we identify 27 high-confidence protein interaction partners of NANOG in mouse embryonic stem cells. These consist of 19 previously unknown partners of NANOG that have not been reported before, including the ten-eleven translocation (TET) family methylcytosine hydroxylase TET1. We confirm physical association of NANOG with TET1, and demonstrate that TET1, in synergy with NANOG, enhances the efficiency of reprogramming. We also find physical association and reprogramming synergy of TET2 with NANOG, and demonstrate that knockdown of TET2 abolishes the reprogramming synergy of NANOG with a catalytically deficient mutant of TET1. These results indicate that the physical interaction between NANOG and TET1/TET2 proteins facilitates reprogramming in a manner that is dependent on the catalytic activity of TET1/TET2. TET1 and NANOG co-occupy genomic loci of genes associated with both maintenance of pluripotency and lineage commitment in embryonic stem cells, and TET1 binding is reduced upon NANOG depletion. Co-expression of NANOG and TET1 increases 5-hydroxymethylcytosine levels at the top-ranked common target loci Esrrb and Oct4 (also called Pou5f1), resulting in priming of their expression before reprogramming to naive pluripotency. We propose that TET1 is recruited by NANOG to enhance the expression of a subset of key reprogramming target genes. These results provide an insight into the reprogramming mechanism of NANOG and uncover a new role for 5-methylcytosine hydroxylases in the establishment of naive pluripotency.

Omega-3 intake is associated with attenuated inflammatory response and cardiac remodeling after myocardial infarction.

BACKGROUND: Myocardial infarction (MI) elicits an intense acute inflammatory response that is essential for cardiac repair. However, an excessive inflammatory response also favors myocardial apoptosis, cardiac remodeling, and cardiovascular mortality. Omega-3 polyunsaturated fatty acids (ω-3) bear anti-inflammatory effects, which may mitigate the inflammatory response during MI. This study investigated whether ω-3 intake is associated with attenuation of the MI-related inflammatory response and cardiac remodeling. METHODS: ST-elevation MI (STEMI) patients (n = 421) underwent clinical, biochemical, nutritional, 3D echocardiogram, Cardiac Magnetic Resonance imaging (CMRi) at 30 days and 3D echocardiogram imaging at six months after the MI. Blood tests were performed at day one (D1) and day five (D5) of hospitalization. Changes in inflammatory markers (ΔD5-D1) were calculated. A validated food frequency questionnaire estimated the nutritional consumption and ω-3 intake in the last 3 months before admission. RESULTS: The intake of ω-3 below the median (< 1.7 g/day) was associated with a short-term increase in hs-C-reactive protein [OR:1.96(1.24-3.10); p = 0.004], Interleukin-2 [OR:2.46(1.20-5.04); p = 0.014], brain-type natriuretic peptide [OR:2.66(1.30-5.44); p = 0.007], left-ventricle end-diastolic volume [OR:5.12(1.11-23.52)]; p = 0.036] and decreases in left-ventricle ejection fraction [OR:2.86(1.47-6.88); p = 0.017] after adjustment for covariates. No differences were observed in the extension of infarcted mass obtained by CMRi. CONCLUSION: These findings suggest that a reduced daily intake of ω-3 may intensify outcome-determining mechanisms after STEMI, such as acute inflammatory response and late left ventricular remodeling. TRIAL REGISTRATION: Clinical Trial Registry number and website: NCT02062554 .

The Hemileia vastatrix effector HvEC-016 suppresses bacterial blight symptoms in coffee genotypes with the SH 1 rust resistance gene.

A number of genes that confer resistance to coffee leaf rust (SH 1-SH 9) have been identified within the genus Coffea, but despite many years of research on this pathosystem, the complementary avirulence genes of Hemileia vastatrix have not been reported. After identification of H. vastatrix effector candidate genes (HvECs) expressed at different stages of its lifecycle, we established an assay to characterize HvEC proteins by delivering them into coffee cells via the type-three secretion system (T3SS) of Pseudomonas syringae pv. garcae (Psgc). Employing a calmodulin-dependent adenylate cyclase assay, we demonstrate that Psgc recognizes a heterologous P. syringae T3SS secretion signal which enables us to translocate HvECs into the cytoplasm of coffee cells. Using this Psgc-adapted effector detector vector (EDV) system, we found that HvEC-016 suppresses the growth of Psgc on coffee genotypes with the SH 1 resistance gene. Suppression of bacterial blight symptoms in SH 1 plants was associated with reduced bacterial multiplication. By contrast, HvEC-016 enhanced bacterial multiplication in SH 1-lacking plants. Our findings suggest that HvEC-016 may be recognized by the plant immune system in a SH 1-dependent manner. Thus, our experimental approach is an effective tool for the characterization of effector/avirulence proteins of this important pathogen.

Senescence impairs successful reprogramming to pluripotent stem cells.

Somatic cells can be reprogrammed into induced pluripotent stem (iPS) cells by overexpressing combinations of factors such as Oct4, Sox2, Klf4, and c-Myc. Reprogramming is slow and stochastic, suggesting the existence of barriers limiting its efficiency. Here we identify senescence as one such barrier. Expression of the four reprogramming factors triggers senescence by up-regulating p53, p16(INK4a), and p21(CIP1). Induction of DNA damage response and chromatin remodeling of the INK4a/ARF locus are two of the mechanisms behind senescence induction. Crucially, ablation of different senescence effectors improves the efficiency of reprogramming, suggesting novel strategies for maximizing the generation of iPS cells.

Controlled hypotension versus normotensive resuscitation strategy for people with ruptured abdominal aortic aneurysm.

BACKGROUND: An abdominal aortic aneurysm (AAA) is the pathological enlargement of the aorta and can develop in both men and women. Progressive aneurysm enlargement can lead to rupture. The rupture of an AAA is frequently fatal and accounts for the death from haemorrhagic shock of at least 45 people per 100,000 population. The outcome of people with ruptured AAA varies among countries and healthcare systems, with mortality ranging from 53% to 90%. Definitive treatment for ruptured AAA includes open surgery or endovascular repair. The management of haemorrhagic shock is crucial for the person's outcome and aims to restore organ perfusion and systolic blood pressure above 100 mm Hg through immediate and aggressive fluid replacement. This rapid fluid replacement is known as the normotensive resuscitation strategy. However, evidence suggests that infusing large volumes of cold fluid causes dilutional and hypothermic coagulopathy. The association of these factors may exacerbate bleeding, resulting in a 'lethal triad' of hypothermia, acidaemia, and coagulopathy. An alternative to the normotensive resuscitation strategy is the controlled (permissive) hypotension resuscitation strategy, with a target systolic blood pressure of 50 to 100 mm Hg. The principle of controlled or hypotensive resuscitation has been used in some management protocols for endovascular repair of ruptured AAA. It may be beneficial in preventing blood loss by avoiding the clot disruption caused by the rapid increase in systolic blood pressure; avoiding dilution of clotting factors, platelets and fibrinogen; and by avoiding the temperature decrease that inhibits enzyme activity involved in platelet and clotting factor function. OBJECTIVES: To compare the effects of controlled (permissive) hypotension resuscitation and normotensive resuscitation strategies for people with ruptured AAA. SEARCH METHODS: The Cochrane Vascular Information Specialist searched the Specialised Register (April 2016) and the Cochrane Register of Studies (CENTRAL (2016, Issue 3)). Clinical trials databases were searched (April 2016) for details of ongoing or unpublished studies. SELECTION CRITERIA: We sought all published and unpublished randomised controlled trial (RCTs) that compared controlled hypotension and normotensive resuscitation strategies for the management of shock in patients with ruptured abdominal aortic aneurysms. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed identified studies for potential inclusion in the review. We used standard methodological procedures in accordance with the Cochrane Handbook for Systematic Review of Interventions. MAIN RESULTS: We identified no RCTs that met the inclusion criteria. AUTHORS' CONCLUSIONS: We found no RCTs that compared controlled hypotension and normotensive resuscitation strategies in the management of haemorrhagic shock in patients with ruptured abdominal aortic aneurysm that assessed mortality, presence of coagulopathy, intensive care unit length of stay, and the presence of myocardial infarct and renal failure. High quality studies that evaluate the best strategy for managing haemorrhagic shock in ruptured abdominal aortic aneurysms are required.

Pharmacological treatment for Buerger's disease.

BACKGROUND: Buerger's disease (thromboangiitis obliterans) is a non-atherosclerotic, segmental inflammatory pathology that most commonly affects the small and medium sized arteries, veins, and nerves in the upper and lower extremities. The etiology is unknown, but involves hereditary susceptibility, tobacco exposure, immune and coagulation responses. In many cases, there is no possibility of revascularization to improve the condition. Pharmacological treatment is an option for patients with severe complications, such as ischaemic ulcers or rest pain. OBJECTIVES: To assess the effectiveness of any pharmacological agent (intravenous or oral) compared with placebo or any other pharmacological agent in patients with Buerger's disease. SEARCH METHODS: The Cochrane Vascular Trials Search Co-ordinator searched their Specialised Register (last searched in April 2015) and the Cochrane Register of Studies (Issue 3, 2015). The review authors searched trial registers and the European grey literature; screened reference lists of relevant studies, and contacted study authors and major pharmaceutical companies. SELECTION CRITERIA: Randomised controlled trials (RCTs) involving pharmacological agents used in the treatment of Buerger's disease. DATA COLLECTION AND ANALYSIS: Two review authors, independently assessed the studies, extracted data and performed data analysis. MAIN RESULTS: Five randomised controlled trials (total 602 participants) compared prostacyclin analogue with placebo, aspirin, or a prostaglandin analogue, and folic acid with placebo. No studies assessed other pharmacological agents such as cilostazol, clopidogrel and pentoxifylline or compared oral versus intravenous prostanoid.Compared with aspirin, intravenous prostacyclin analogue iloprost improved ulcer healing (risk ratio (RR) 2.65; 95% confidence interval (CI) 1.15 to 6.11; 98 participants; one study; moderate quality evidence), and helped to eradicate rest pain after 28 days (RR 2.28; 95% CI 1.48 to 3.52; 133 participants; one study; moderate quality evidence), although amputation rates were similar six months after treatment (RR 0.32; 95% CI 0.09 to 1.15; 95 participants; one study; moderate quality evidence). When comparing prostacyclin (iloprost and clinprost) with prostaglandin (alprostadil) analogues, ulcer healing was similar (RR 1.13; 95% CI 0.76 to 1.69; 89 participants; two studies; I² = 0%; very low quality evidence), as was the eradication of rest pain after 28 days (RR 1.57; 95% CI 0.72 to 3.44; 38 participants; one study; low quality evidence), while amputation rates were not measured. Compared with placebo, the effects of oral prostacyclin analogue iloprost were similar for: healing ischaemic ulcers (iloprost 200 mcg: RR 1.11; 95% CI 0.54 to 2.29; 133 participants; one study; moderate quality evidence, and iloprost 400 mcg: RR 0.90; 95% CI 0.42 to 1.93; 135 participants; one study; moderate quality evidence), eradication of rest pain after eight weeks (iloprost 200 mcg: RR 1.14; 95% CI 0.79 to 1.63; 207 participants; one study; moderate quality evidence, and iloprost 400 mcg: RR 1.11; 95% CI 0.77 to 1.59; 201 participants; one study; moderate quality evidence), and amputation rates after six months (iloprost 200 mcg: RR 0.54; 95% CI 0.19 to 1.56; 209 participants; one study, and iloprost 400 mcg: RR 0.42; 95% CI 0.13 to 1.31; 213 participants; one study). When comparing folic acid with placebo in patients with Buerger's disease and hyperhomocysteinaemia, pain scores were similar, there were no new cases of amputation in either group, and ulcer healing was not assessed (very low quality evidence).Treatment side effects such as headaches, flushing or nausea were not associated with treatment interruptions or more serious consequences. Outcomes such as amputation-free survival, walking distance or pain-free walking distance, and ankle brachial index were not assessed by any study.Overall, the quality of the evidence was very low to moderate, with few studies, small numbers of participants, variation in severity of disease of participants between studies and missing information regarding for example baseline tobacco exposure. AUTHORS' CONCLUSIONS: Moderate quality evidence suggests that intravenous iloprost (prostacyclin analogue) is more effective than aspirin for eradicating rest pain and healing ischaemic ulcers in Buerger's disease, but oral iloprost is not more effective than placebo. Verylow and low quality evidence suggests there is no difference between prostacyclin (iloprost and clinprost) and the prostaglandin analogue alprostadil for healing ulcers and relieving pain respectively in severe Buerger's disease. Very-low quality evidence suggests there is no difference in pain scores and amputation rates between folic acid and placebo, in people with Buerger's disease and hyperhomocysteinaemia. High quality trials assessing the effectiveness of pharmacological agents (intravenous or oral) in people with Buerger's disease are needed.

Pharmacological treatment for Buerger's disease.

BACKGROUND: Buerger's disease (thromboangiitis obliterans) is a non-atherosclerotic, segmental inflammatory pathology that most commonly affects the small and medium sized arteries, veins, and nerves in the upper and lower extremities. The etiology is unknown, but involves hereditary susceptibility, tobacco exposure, immune and coagulation responses. In many cases, there is no possibility of revascularization to improve the condition. Pharmacological treatment is an option for patients with severe complications, such as ischaemic ulcers or rest pain. OBJECTIVES: To assess the effectiveness of any pharmacological agent (intravenous or oral) compared with placebo or any other pharmacological agent in patients with Buerger's disease. SEARCH METHODS: The Cochrane Vascular Trials Search Co-ordinator searched their Specialised Register (last searched in April 2015) and the Cochrane Register of Studies (Issue 3, 2015). The review authors searched trial registers and the European grey literature; screened reference lists of relevant studies, and contacted study authors and major pharmaceutical companies. SELECTION CRITERIA: Randomised controlled trials (RCTs) involving pharmacological agents used in the treatment of Buerger's disease. DATA COLLECTION AND ANALYSIS: Two review authors, independently assessed the studies, extracted data and performed data analysis. MAIN RESULTS: Five randomised controlled trials (total 602 participants) compared prostacyclin analogue with placebo, aspirin, or a prostaglandin analogue, and folic acid with placebo. No studies assessed other pharmacological agents such as cilostazol, clopidogrel and pentoxifylline or compared oral versus intravenous prostanoid.Compared with aspirin, intravenous prostacyclin analogue iloprost improved ulcer healing (risk ratio (RR) 2.65; 95% confidence interval (CI) 1.15 to 6.11; 98 participants; one study; moderate quality evidence), and helped to eradicate rest pain after 28 days (RR 2.28; 95% CI 1.48 to 3.52; 133 participants; one study; moderate quality evidence), although amputation rates were similar six months after treatment (RR 0.32; 95% CI 0.09 to 1.15; 95 participants; one study; moderate quality evidence). When comparing prostacyclin (iloprost and clinprost) with prostaglandin (alprostadil) analogues, ulcer healing was similar (RR 1.13; 95% CI 0.76 to 1.69; 89 participants; two studies; I² = 0%; very low quality evidence), as was the eradication of rest pain after 28 days (RR 1.57; 95% CI 0.72 to 3.44; 38 participants; one study; low quality evidence), while amputation rates were not measured. Compared with placebo, the effects of oral prostacyclin analogue iloprost were similar for: healing ischaemic ulcers (iloprost 200 mcg: RR 1.11; 95% CI 0.54 to 2.29; 133 participants; one study; moderate quality evidence, and iloprost 400 mcg: RR 0.90; 95% CI 0.42 to 1.93; 135 participants; one study; moderate quality evidence), eradication of rest pain after eight weeks (iloprost 200 mcg: RR 1.14; 95% CI 0.79 to 1.63; 207 participants; one study; moderate quality evidence, and iloprost 400 mcg: RR 1.11; 95% CI 0.77 to 1.59; 201 participants; one study; moderate quality evidence), and amputation rates after six months (iloprost 200 mcg: RR 0.54; 95% CI 0.19 to 1.56; 209 participants; one study, and iloprost 400 mcg: RR 0.42; 95% CI 0.13 to 1.31; 213 participants; one study). When comparing folic acid with placebo in patients with Buerger's disease and hyperhomocysteinaemia, pain scores were similar, there were no new cases of amputation in either group, and ulcer healing was not assessed (very low quality evidence).Treatment side effects such as headaches, flushing or nausea were not associated with treatment interruptions or more serious consequences. Outcomes such as amputation-free survival, walking distance or pain-free walking distance, and ankle brachial index were not assessed by any study.Overall, the quality of the evidence was very low to moderate, with few studies, small numbers of participants, variation in severity of disease of participants between studies and missing information regarding for example baseline tobacco exposure. AUTHORS' CONCLUSIONS: Moderate quality evidence suggests that intravenous iloprost (prostacyclin analogue) is more effective than aspirin for eradicating rest pain and healing ischaemic ulcers in Buerger's disease, but oral iloprost is not more effective than placebo. Verylow and low quality evidence suggests there is no difference between prostacyclin (iloprost and clinprost) and the prostaglandin analogue alprostadil for healing ulcers and relieving pain respectively in severe Buerger's disease. Very-low quality evidence suggests there is no difference in pain scores and amputation rates between folic acid and placebo, in people with Buerger's disease and hyperhomocysteinaemia. High quality trials assessing the effectiveness of pharmacological agents (intravenous or oral) in people with Buerger's disease are needed.

Incidence of apoptosis after retinoids and insulin-like growth factor-I (IGF-I) supplementation during goat in vitro embryo production.

The addition of growth factors and vitamins enhances goat embryonic development in vitro. However, few attempts have been reported trying to identify supplementation regimens for oocyte maturation or embryo culture with additive properties. The present report was aimed to evaluate if retinoids [0.3 µM retinyl acetate (RAc) and 0.5 µM 9-cis-retinoic acid (RA)] supplementation during goat oocyte maturation and retinoids and/or 50 ng mL-1 IGF-I during embryo culture synergically enhanced embryonic development while diminishing the incidence of apoptosis. All combinations of RAc and RA treatment produced blastocysts with similar efficiencies, while IGF-I enhanced embryos yields irrespectively of retinoid addition. Moreover, retinoids and IGF-I supplementation showed similar caspase activity or DNA fragmentation indexes in blastocysts. In conclusion, supplementation with retinoids and IGF-I during goat embryo culture enhances blastocysts development without synergic reduction of apoptosis.

Revision of Begomovirus taxonomy based on pairwise sequence comparisons.

Viruses of the genus Begomovirus (family Geminiviridae) are emergent pathogens of crops throughout the tropical and subtropical regions of the world. By virtue of having a small DNA genome that is easily cloned, and due to the recent innovations in cloning and low-cost sequencing, there has been a dramatic increase in the number of available begomovirus genome sequences. Even so, most of the available sequences have been obtained from cultivated plants and are likely a small and phylogenetically unrepresentative sample of begomovirus diversity, a factor constraining taxonomic decisions such as the establishment of operationally useful species demarcation criteria. In addition, problems in assigning new viruses to established species have highlighted shortcomings in the previously recommended mechanism of species demarcation. Based on the analysis of 3,123 full-length begomovirus genome (or DNA-A component) sequences available in public databases as of December 2012, a set of revised guidelines for the classification and nomenclature of begomoviruses are proposed. The guidelines primarily consider a) genus-level biological characteristics and b) results obtained using a standardized classification tool, Sequence Demarcation Tool, which performs pairwise sequence alignments and identity calculations. These guidelines are consistent with the recently published recommendations for the genera Mastrevirus and Curtovirus of the family Geminiviridae. Genome-wide pairwise identities of 91 % and 94 % are proposed as the demarcation threshold for begomoviruses belonging to different species and strains, respectively. Procedures and guidelines are outlined for resolving conflicts that may arise when assigning species and strains to categories wherever the pairwise identity falls on or very near the demarcation threshold value.

Zfp281 mediates Nanog autorepression through recruitment of the NuRD complex and inhibits somatic cell reprogramming.

The homeodomain transcription factor Nanog plays an important role in embryonic stem cell (ESC) self-renewal and is essential for acquiring ground-state pluripotency during reprogramming. Understanding how Nanog is transcriptionally regulated is important for further dissecting mechanisms of ESC pluripotency and somatic cell reprogramming. Here, we report that Nanog is subjected to a negative autoregulatory mechanism, i.e., autorepression, in ESCs, and that such autorepression requires the coordinated action of the Nanog partner and transcriptional repressor Zfp281. Mechanistically, Zfp281 recruits the NuRD repressor complex onto the Nanog locus and maintains its integrity to mediate Nanog autorepression and, functionally, Zfp281-mediated Nanog autorepression presents a roadblock to efficient somatic cell reprogramming. Our results identify a unique transcriptional regulatory mode of Nanog gene expression and shed light into the mechanistic understanding of Nanog function in pluripotency and reprogramming.

Use of retinoids during oocyte maturation diminishes apoptosis in caprine embryos.

Exposure of caprine oocytes and embryos to retinoids enhances embryonic development, but the mechanisms governing this phenomenon have not been characterised. The aim of the present study was to evaluate if the incidence of apoptosis is affected by the addition of retinyl acetate (RAc) and 9-cis-retinoic acid (RA) during in vitro maturation (IVM) of caprine oocytes. Embryonic development was recorded on days 3 and 8 post-fertilisation, and apoptosis was measured by caspase activity and DNA fragmentation (TUNEL assay). Control zygotes had lower capacity to cleave and reach the blastocyst stage (24.45 ± 2.32 and 5.32 ± 0.81, respectively) than those of RAc- (29.96 ± 1.62 and 7.94 ± 0.93, respectively) and RA-treated groups (30.12 ± 1.51 and 7.36 ± 1.02, respectively). Oocytes and blastocysts positive for TUNEL assay were more frequent, respectively, in the controls (8.20 ± 0.78, 8.70 ± 1.05) than in RAc (5.60 ± 0.52, 4.80 ± 0.51) and RA (6.40 ± 0.69, 5.40 ± 0.69). Caspase activity did not differ between control oocytes (7.20 ± 0.91), RAc (6.60 ± 0.68) and RA (7.30 ± 0.67), but it was reduced in RAc- (5.05 ± 0.62) and RA-treated blastocysts (5.75 ± 0.22) compared to controls (8.35 ± 0.71). These results indicate that the addition of retinoids during IVM increases the developmental potential of goat embryos with a concomitant reduction in apoptosis rates.