Development of the mammalian liver and ventral pancreas is dependent on GATA4

<p>Abstract</p> <p>Background</p> <p>In the mouse, the parenchyma of both the liver and ventral pancreas is specified from adjacent domains of the ventral foregut endoderm. GATA4, a zinc finger transcription factor, is strongly expressed in these endodermal domains and molecular analyses have implicated GATA4 in potentiating liver gene expression during the onset of hepatogenesis. We therefore hypothesized that GATA4 has an integral role in controlling the early stages of pancreatic and liver development.</p> <p>Results</p> <p>To determine whether GATA4 contributes to development of either the pancreas or liver we characterized the formation of pancreatic and hepatic tissues in embryos derived from <it>Gata4</it>^-/-ES cells by tetraploid embryo complementation. In the absence of GATA4, development of the liver and ventral pancreas was disrupted. At embryonic day (E) 9.5, the liver bud failed to expand although, contrary to expectations, the hepatic endoderm was able to form a pseudo-stratified epithelial liver bud that expressed hepatic genes. Moreover, as we had shown previously, the embryos lacked septum transversum mesenchyme suggesting that liver defects may be cell non-autonomous. Analyses of pancreatic development revealed a complete absence of the ventral but not the dorsal pancreas in <it>Gata4</it>^-/-embryos. Moreover, <it>Gata6</it>^-/-embryos displayed a similar, although less dramatic phenotype, suggesting a critical role for multiple GATA factors at the earliest stages of ventral pancreas development.</p> <p>Conclusion</p> <p>This study defines integral roles for GATA factors in controlling early development of the mammalian liver and pancreas.</p

A murine specific expansion of the Rhox cluster involved in embryonic stem cell biology is under natural selection

BACKGROUND: The rodent specific reproductive homeobox (Rhox) gene cluster on the X chromosome has been reported to contain twelve homeobox-containing genes, Rhox1-12. RESULTS: We have identified a 40 kb genomic region within the Rhox cluster that is duplicated eight times in tandem resulting in the presence of eight paralogues of Rhox2 and Rhox3 and seven paralogues of Rhox4. Transcripts have been identified for the majority of these paralogues and all but three are predicted to produce full-length proteins with functional potential. We predict that there are a total of thirty-two Rhox genes at this genomic location, making it the most gene-rich homoeobox cluster identified in any species. From the 95% sequence similarity between the eight duplicated genomic regions and the synonymous substitution rate of the Rhox2, 3 and 4 paralogues we predict that the duplications occurred after divergence of mouse and rat and represent the youngest homoeobox cluster identified to date. Molecular evolutionary analysis reveals that this cluster is an actively evolving region with Rhox2 and 4 paralogues under diversifying selection and Rhox3 evolving neutrally. The biological importance of this duplication is emphasised by the identification of an important role for Rhox2 and Rhox4 in regulating the initial stages of embryonic stem (ES) cell differentiation. CONCLUSION: The gene rich Rhox cluster provides the mouse with significant biological novelty that we predict could provide a substrate for speciation. Moreover, this unique cluster may explain species differences in ES cell derivation and maintenance between mouse, rat and human

Common genetic variation drives molecular heterogeneity in human iPSCs.

Technology utilizing human induced pluripotent stem cells (iPS cells) has enormous potential to provide improved cellular models of human disease. However, variable genetic and phenotypic characterization of many existing iPS cell lines limits their potential use for research and therapy. Here we describe the systematic generation, genotyping and phenotyping of 711 iPS cell lines derived from 301 healthy individuals by the Human Induced Pluripotent Stem Cells Initiative. Our study outlines the major sources of genetic and phenotypic variation in iPS cells and establishes their suitability as models of complex human traits and cancer. Through genome-wide profiling we find that 5-46% of the variation in different iPS cell phenotypes, including differentiation capacity and cellular morphology, arises from differences between individuals. Additionally, we assess the phenotypic consequences of genomic copy-number alterations that are repeatedly observed in iPS cells. In addition, we present a comprehensive map of common regulatory variants affecting the transcriptome of human pluripotent cells

UK Kidney association clinical practice guideline: sodium-glucose co-transporter-2 (SGLT-2) inhibition in adults with kidney disease 2023 UPDATE

Large placebo-controlled trials have demonstrated kidney and cardiovascular clinical benefits of SGLT-2 inhibitors. Data from the EMPA-KIDNEY and DELIVER trials and associated meta-analyses triggered an update to the UK Kidney Association Clinical Practice Guideline on Sodium-Glucose Co-transporter-2 (SGLT-2) Inhibition in Adults with Kidney Disease. We provide a summary of the full guideline and highlight the rationale for recent updates. The use of SGLT-2 inhibitors in people with specific medical conditions, including type 1 diabetes, kidney transplants, and people admitted to hospital with heart failure is also considered, along with Recommendations for future research and Recommendations for implementation. A full “lay” summary of the guidelines is provided as an appendix to ensure that these guidelines are accessible and understandable to people who are not medical professionals

Integrated transcriptomic and proteomic analysis of the global response of Wolbachia to doxycycline-induced stress

The bacterium Wolbachia (order Rickettsiales), representing perhaps the most abundant vertically transmitted microbe worldwide, infects arthropods and filarial nematodes. In arthropods, Wolbachia can induce reproductive alterations and interfere with the transmission of several arthropod-borne pathogens. In addition, Wolbachia is an obligate mutualist of the filarial parasites that cause lymphatic filariasis and onchocerciasis in the tropics. Targeting Wolbachia with tetracycline antibiotics leads to sterilisation and ultimately death of adult filariae. However, several weeks of treatment are required, restricting the implementation of this control strategy. To date, the response of Wolbachia to stress has not been investigated, and almost nothing is known about global regulation of gene expression in this organism. We exposed an arthropod Wolbachia strain to doxycycline in vitro, and analysed differential expression by directional RNA-seq and label-free, quantitative proteomics. We found that Wolbachia responded not only by modulating expression of the translation machinery, but also by upregulating nucleotide synthesis and energy metabolism, while downregulating outer membrane proteins. Moreover, Wolbachia increased the expression of a key component of the twin-arginine translocase (tatA) and a phosphate ABC transporter ATPase (PstB); the latter is associated with decreased susceptibility to antimicrobials in free-living bacteria. Finally, the downregulation of 6S RNA during translational inhibition suggests that this small RNA is involved in growth rate control. Despite its highly reduced genome, Wolbachia shows a surprising ability to regulate gene expression during exposure to a potent stressor. Our findings have general relevance for the chemotherapy of obligate intracellular bacteria and the mechanistic basis of persistence in the Rickettsiales

Genome-Wide Association Study in BRCA1 Mutation Carriers Identifies Novel Loci Associated with Breast and Ovarian Cancer Risk

BRCA1-associated breast and ovarian cancer risks can be modified by common genetic variants. To identify further cancer risk-modifying loci, we performed a multi-stage GWAS of 11,705 BRCA1 carriers (of whom 5,920 were diagnosed with breast and 1,839 were diagnosed with ovarian cancer), with a further replication in an additional sample of 2,646 BRCA1 carriers. We identified a novel breast cancer risk modifier locus at 1q32 for BRCA1 carriers (rs2290854, P = 2.7×10-8, HR = 1.14, 95% CI: 1.09-1.20). In addition, we identified two novel ovarian cancer risk modifier loci: 17q21.31 (rs17631303, P = 1.4×10-8, HR = 1.27, 95% CI: 1.17-1.38) and 4q32.3 (rs4691139, P = 3.4×10-8, HR = 1.20, 95% CI: 1.17-1.38). The 4q32.3 locus was not associated with ovarian cancer risk in the general population or BRCA2 carriers, suggesting a BRCA1-specific associat

Hyperoxemia and excess oxygen use in early acute respiratory distress syndrome : Insights from the LUNG SAFE study

Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Concerns exist regarding the prevalence and impact of unnecessary oxygen use in patients with acute respiratory distress syndrome (ARDS). We examined this issue in patients with ARDS enrolled in the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. Methods: In this secondary analysis of the LUNG SAFE study, we wished to determine the prevalence and the outcomes associated with hyperoxemia on day 1, sustained hyperoxemia, and excessive oxygen use in patients with early ARDS. Patients who fulfilled criteria of ARDS on day 1 and day 2 of acute hypoxemic respiratory failure were categorized based on the presence of hyperoxemia (PaO2 > 100 mmHg) on day 1, sustained (i.e., present on day 1 and day 2) hyperoxemia, or excessive oxygen use (FIO2 ≥ 0.60 during hyperoxemia). Results: Of 2005 patients that met the inclusion criteria, 131 (6.5%) were hypoxemic (PaO2 < 55 mmHg), 607 (30%) had hyperoxemia on day 1, and 250 (12%) had sustained hyperoxemia. Excess FIO2 use occurred in 400 (66%) out of 607 patients with hyperoxemia. Excess FIO2 use decreased from day 1 to day 2 of ARDS, with most hyperoxemic patients on day 2 receiving relatively low FIO2. Multivariate analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FIO2 use and adverse clinical outcomes. Mortality was 42% in patients with excess FIO2 use, compared to 39% in a propensity-matched sample of normoxemic (PaO2 55-100 mmHg) patients (P = 0.47). Conclusions: Hyperoxemia and excess oxygen use are both prevalent in early ARDS but are most often non-sustained. No relationship was found between hyperoxemia or excessive oxygen use and patient outcome in this cohort. Trial registration: LUNG-SAFE is registered with ClinicalTrials.gov, NCT02010073publishersversionPeer reviewe

Sex difference and intra-operative tidal volume: Insights from the LAS VEGAS study

BACKGROUND: One key element of lung-protective ventilation is the use of a low tidal volume (VT). A sex difference in use of low tidal volume ventilation (LTVV) has been described in critically ill ICU patients.OBJECTIVES: The aim of this study was to determine whether a sex difference in use of LTVV also exists in operating room patients, and if present what factors drive this difference.DESIGN, PATIENTS AND SETTING: This is a posthoc analysis of LAS VEGAS, a 1-week worldwide observational study in adults requiring intra-operative ventilation during general anaesthesia for surgery in 146 hospitals in 29 countries.MAIN OUTCOME MEASURES: Women and men were compared with respect to use of LTVV, defined as VT of 8 ml kg-1 or less predicted bodyweight (PBW). A VT was deemed 'default' if the set VT was a round number. A mediation analysis assessed which factors may explain the sex difference in use of LTVV during intra-operative ventilation.RESULTS: This analysis includes 9864 patients, of whom 5425 (55%) were women. A default VT was often set, both in women and men; mode VT was 500 ml. Median [IQR] VT was higher in women than in men (8.6 [7.7 to 9.6] vs. 7.6 [6.8 to 8.4] ml kg-1 PBW, P &lt; 0.001). Compared with men, women were twice as likely not to receive LTVV [68.8 vs. 36.0%; relative risk ratio 2.1 (95% CI 1.9 to 2.1), P &lt; 0.001]. In the mediation analysis, patients' height and actual body weight (ABW) explained 81 and 18% of the sex difference in use of LTVV, respectively; it was not explained by the use of a default VT.CONCLUSION: In this worldwide cohort of patients receiving intra-operative ventilation during general anaesthesia for surgery, women received a higher VT than men during intra-operative ventilation. The risk for a female not to receive LTVV during surgery was double that of males. Height and ABW were the two mediators of the sex difference in use of LTVV.TRIAL REGISTRATION: The study was registered at Clinicaltrials.gov, NCT01601223

Key stakeholder perceptions about consent to participate in acute illness research: a rapid, systematic review to inform epi/pandemic research preparedness

Background A rigorous research response is required to inform clinical and public health decision-making during an epi/pandemic. However, the ethical conduct of such research, which often involves critically ill patients, may be complicated by the diminished capacity to consent and an imperative to initiate trial therapies within short time frames. Alternative approaches to taking prospective informed consent may therefore be used. We aimed to rapidly review evidence on key stakeholder (patients, their proxy decision-makers, clinicians and regulators) views concerning the acceptability of various approaches for obtaining consent relevant to pandemic-related acute illness research. Methods We conducted a rapid evidence review, using the Internet, database and hand-searching for English language empirical publications from 1996 to 2014 on stakeholder opinions of consent models (prospective informed, third-party, deferred, or waived) used in acute illness research. We excluded research on consent to treatment, screening, or other such procedures, non-emergency research and secondary studies. Papers were categorised, and data summarised using narrative synthesis. Results We screened 689 citations, reviewed 104 full-text articles and included 52. Just one paper related specifically to pandemic research. In other emergency research contexts potential research participants, clinicians and research staff found third-party, deferred, and waived consent to be acceptable as a means to feasibly conduct such research. Acceptability to potential participants was motivated by altruism, trust in the medical community, and perceived value in medical research and decreased as the perceived risks associated with participation increased. Discrepancies were observed in the acceptability of the concept and application or experience of alternative consent models. Patients accepted clinicians acting as proxy-decision makers, with preference for two decision makers as invasiveness of interventions increased. Research regulators were more cautious when approving studies conducted with alternative consent models; however, their views were generally under-represented. Conclusions Third-party, deferred, and waived consent models are broadly acceptable to potential participants, clinicians and/or researchers for emergency research. Further consultation with key stakeholders, particularly with regulators, and studies focused specifically on epi/pandemic research, are required. We highlight gaps and recommendations to inform set-up and protocol development for pandemic research and institutional review board processes