Medical Research Council

About: Medical Research Council is a government organization based out in London, United Kingdom. It is known for research contribution in the topics: Population & Malaria. The organization has 16430 authors who have published 19150 publications receiving 1475494 citations.

Herpes Simplex Virus Type 1 Immediate-Early Protein ICP0 and Its Isolated RING Finger Domain Act as Ubiquitin E3 Ligases In Vitro

Abstract: Proteasome-dependent degradation of ubiquitinated proteins plays a key role in many important cellular processes. Ubiquitination requires the E1 ubiquitin activating enzyme, an E2 ubiquitin conjugating enzyme, and frequently a substrate-specific ubiquitin protein ligase (E3). One class of E3 ubiquitin ligases has been shown to contain a common zinc-binding RING finger motif. We have previously shown that herpes simplex virus type 1 ICP0, itself a RING finger protein, induces the proteasome-dependent degradation of several cellular proteins and induces the accumulation of colocalizing conjugated ubiquitin in vivo. We now report that both full-length ICP0 and its isolated RING finger domain induce the accumulation of polyubiquitin chains in vitro in the presence of E1 and the E2 enzymes UbcH5a and UbcH6. Mutations within the RING finger region that abolish the in vitro ubiquitination activity also cause severe reductions in ICP0 activity in other assays. We conclude that ICP0 has the potential to act as an E3 ubiquitin ligase during viral infection and to target specific cellular proteins for destruction by the 26S proteasome.

Enumeration of human colonic bacteria producing phenolic and indolic compounds : effects of pH, carbohydrate availability and retention time on dissimilatory aromatic amino acid metabolism

Abstract: Concentrations of phenolic compounds in human gut contents were more than fourfold higher in the distal colon (6.2 mmol kg-1) compared to the proximal bowel (1.4 mmol kg-1). Tryptophan metabolites were never found in more than trace amounts in large intestinal contents and phenol substituted fatty acids were the major products of aromatic amino acid fermentation that accumulated in the proximal colon, whereas phenol and p-cresol were more important in the distal gut, accounting for 70% of all products of dissimilatory aromatic amino acid metabolism. In vitro incubations of colonic material showed that phenol was produced most rapidly (1.0 mumol g-1 h-1), whereas indole was formed comparatively slowly (0.06 mumol g-1 h-1). Most probable number (MPN) estimations demonstrated that large populations of phenol and indole producing bacteria occur in the large intestine (range log10 9.8-11.5 (g dry wt faeces)-1, mean 10.6, N = 7). With respect to phenolic compounds, phenylacetate and phenylpropionate producers predominated, while indoleacetate-forming bacteria were the major tryptophan-utilizing organisms. Quantitation of products of dissimilatory aromatic amino acid metabolism in MPN tubes showed that phenol and phenylpropionate mainly accumulated at low sample dilutions, whereas phenylacetate, p-cresol, indoleacetate and indolepropionate were formed in greatest amounts at high sample dilutions. The significance of pH and carbohydrate availability with respect to aromatic amino acid metabolism was shown in batch culture fermentation studies, where net production of phenolic compounds by mixed populations of intestinal bacteria was reduced by approximately 33% during growth at pH 5.5 compared to pH 6.8, and by 60% in the presence of a fermentable carbohydrate. Experiments with 16 species of intestinal bacteria belonging to six different genera showed that environmental factors such as low pH and high carbohydrate availability markedly reduced dissimilatory aromatic amino acid metabolism in some organisms, but stimulated this process in others. A three-stage continuous culture model of the colon was used to investigate the effect of system retention time (27.1 or 66.7 h) on aromatic amino acid fermentation. Qualitative and quantitative increases in phenol production occurred from vessel 1 to vessel 3 in this model. Concentrations of phenolic compounds in vessel 3 were three times greater at R = 66.7 h compared to R = 27.1 h. Phenol and p-cresol were not detected in vessel 1, though formation of these metabolites increased from vessel 2 to vessel 3, in a pattern similar to that observed in the distal colon.

Adjuvant bevacizumab-containing therapy in triple-negative breast cancer (BEATRICE): primary results of a randomised, phase 3 trial

Abstract: Summary Background The addition of bevacizumab to chemotherapy improves progression-free survival in metastatic breast cancer and pathological complete response rates in the neoadjuvant setting. Micrometastases are dependent on angiogenesis, suggesting that patients might benefit from anti-angiogenic strategies in the adjuvant setting. We therefore assessed the addition of bevacizumab to chemotherapy in the adjuvant setting for women with triple-negative breast cancer. Methods For this open-label, randomised phase 3 trial we recruited patients with centrally confirmed triple-negative operable primary invasive breast cancer from 360 sites in 37 countries. We randomly allocated patients aged 18 years or older (1:1 with block randomisation; stratified by nodal status, chemotherapy [with an anthracycline, taxane, or both], hormone receptor status [negative vs low], and type of surgery) to receive a minimum of four cycles of chemotherapy either alone or with bevacizumab (equivalent of 5 mg/kg every week for 1 year). The primary endpoint was invasive disease-free survival (IDFS). Efficacy analyses were based on the intention-to-treat population, safety analyses were done on all patients who received at least one dose of study drug, and plasma biomarker analyses were done on all treated patients consenting to biomarker analyses and providing a measurable baseline plasma sample. This trial is registered with ClinicalTrials.gov, number NCT00528567. Findings Between Dec 3, 2007, and March 8, 2010, we randomly assigned 1290 patients to receive chemotherapy alone and 1301 to receive bevacizumab plus chemotherapy. Most patients received anthracycline-containing therapy; 1638 (63%) of the 2591 patients had node-negative disease. At the time of analysis of IDFS, median follow-up was 31·5 months (IQR 25·6–36·8) in the chemotherapy-alone group and 32·0 months (27·5–36·9) in the bevacizumab group. At the time of the primary analysis, IDFS events had been reported in 205 patients (16%) in the chemotherapy-alone group and in 188 patients (14%) in the bevacizumab group (hazard ratio [HR] in stratified log-rank analysis 0·87, 95% CI 0·72–1·07; p=0·18). 3-year IDFS was 82·7% (95% CI 80·5–85·0) with chemotherapy alone and 83·7% (81·4–86·0) with bevacizumab and chemotherapy. After 200 deaths, no difference in overall survival was noted between the groups (HR 0·84, 95% CI 0·64–1·12; p=0·23). Exploratory biomarker assessment suggests that patients with high pre-treatment plasma VEGFR-2 might benefit from the addition of bevacizumab (Cox interaction test p=0·029). Use of bevacizumab versus chemotherapy alone was associated with increased incidences of grade 3 or worse hypertension (154 patients [12%] vs eight patients [1%]), severe cardiac events occurring at any point during the 18-month safety reporting period (19 [1%] vs two [ vs 30 [2%]); we recorded no increase in fatal adverse events with bevacizumab (four [ vs three [ Interpretation Bevacizumab cannot be recommended as adjuvant treatment in unselected patients with triple-negative breast cancer. Further follow-up is needed to assess the potential effect of bevacizumab on overall survival. Funding F Hoffmann-La Roche.

Common variants in WFS1 confer risk of type 2 diabetes

Abstract: We studied genes involved in pancreatic beta cell function and survival, identifying associations between SNPs in WFS1 and diabetes risk in UK populations that we replicated in an Ashkenazi population and in additional UK studies. In a pooled analysis comprising 9,533 cases and 11,389 controls, SNPs in WFS1 were strongly associated with diabetes risk. Rare mutations in WFS1 cause Wolfram syndrome; using a gene-centric approach, we show that variation in WFS1 also predisposes to common type 2 diabetes.

Obesity in mice with adipocyte-specific deletion of clock component Arntl

Abstract: Adipocytes store excess energy in the form of triglycerides and signal the levels of stored energy to the brain. Here we show that adipocyte-specific deletion of Arntl (also known as Bmal1), a gene encoding a core molecular clock component, results in obesity in mice with a shift in the diurnal rhythm of food intake, a result that is not seen when the gene is disrupted in hepatocytes or pancreatic islets. Changes in the expression of hypothalamic neuropeptides that regulate appetite are consistent with feedback from the adipocyte to the central nervous system to time feeding behavior. Ablation of the adipocyte clock is associated with a reduced number of polyunsaturated fatty acids in adipocyte triglycerides. This difference between mutant and wild-type mice is reflected in the circulating concentrations of polyunsaturated fatty acids and nonesterified polyunsaturated fatty acids in hypothalamic neurons that regulate food intake. Thus, this study reveals a role for the adipocyte clock in the temporal organization of energy regulation, highlights timing as a modulator of the adipocyte-hypothalamic axis and shows the impact of timing of food intake on body weight.