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Tyrosine-1 of RNA polymerase II CTD controls global termination of gene transcription in mammals.
The carboxy-terminal domain (CTD) of RNA polymerase (Pol) II is composed of a repetition of YSPTSPS heptads and functions as a loading platform for protein complexes that regulate transcription, splicing, and maturation of RNAs. Here, we studied mammalian CTD mutants to analyze the function of tyrosine1 residues in the transcription cycle. Mutation of 3/4 of the tyrosine residues (YFFF mutant) resulted in a massive read-through transcription phenotype in the antisense direction of promoters as well as in the 3' direction several hundred kilobases downstream of genes. The YFFF mutant shows reduced Pol II at promoter-proximal pause sites, a loss of interaction with the Mediator and Integrator complexes, and impaired recruitment of these complexes to chromatin. Consistent with these observations, Pol II loading at enhancers and maturation of snRNAs are altered in the YFFF context genome-wide. We conclude that tyrosine1 residues of the CTD control termination of transcription by Pol II
Association of in utero persistent organic pollutant exposure with placental thyroid hormones.
In utero exposure to persistent organic pollutants (POPs) can result in thyroid function disorder, leading to concerns about their impact on fetal and neonatal development. The associations between placental levels of various POPs and thyroid hormones (THs) were investigated. In a prospective Danish study initially established for assessing congenital cryptorchidism, 58 placenta samples were collected from mothers of boys born with (n =28) and without (n =30) cryptorchidism. The concentrations of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), organotin chemicals (OTCs), organochlorine pesticides (OCPs), T 4, T 3, and rT 3 were measured. The associations between placental THs and various POPs were analyzed using multiple linear regression. Five PBDEs, 35 PCBs, 14 PCDD/Fs, 3 OTCs, 25 OCPs, T 4, T 3, and rT 3 were measured. No correlation between THs and the odds of cryptorchidism was found. Several POPs were significantly associated with THs: (1) T 4 was inversely associated with BDEs 99, 100, Î£ PBDE, and 2378-TeCDD, and positively associated with 1234678-HpCDF; (2) T 3 was positively associated with 2378-TeCDF and 12378-PeCDF; and (3) rT 3 was positively associated with PCB 81, 12378-PeCDF, and 234678-HxCDF, and inversely associated with tributyltin, Î£ OTC, and methoxychlor. These results revealed that POP exposures were associated with TH levels in placenta, which may be a possible mechanism for the impacts of POP exposures on children's growth and development. This study provides new insight into the complexity of thyroid-disrupting properties of POPs. More research is needed to elucidate the biological consequences of POP exposures
Mixing omics: Combining genetics and metabolomics to study rheumatic diseases.
Metabolomics is an exciting field in systems biology that provides a direct readout of the biochemical activities taking place within an individual at a particular point in time. Metabolite levels are influenced by many factors, including disease status, environment, medications, diet and, importantly, genetics. Thanks to their dynamic nature, metabolites are useful for diagnosis and prognosis, as well as for predicting and monitoring the efficacy of treatments. At the same time, the strong links between an individual's metabolic and genetic profiles enable the investigation of pathways that underlie changes in metabolite levels. Thus, for the field of metabolomics to yield its full potential, researchers need to take into account the genetic factors underlying the production of metabolites, and the potential role of these metabolites in disease processes. In this Review, the methodological aspects related to metabolomic profiling and any potential links between metabolomics and the genetics of some of the most common rheumatic diseases are described. Links between metabolomics, genetics and emerging fields such as the gut microbiome and proteomics are also discussed
Impact of anxiety on prehospital delay in patients with acute myocardial infarction.
Background: Prehospital delay in seeking treatment in patients with acute myocardial infarction(AMI)is a vital factor on patients outcome.However,most studies focus on demographic factors,clinical symptoms and display of AMI,and cognitive aspects,and there is a lack of systematic research on social-psychological factors.As a common psychological factor,anxiety and its effects over AMI patient's prehospital time(PHT)has not yet been reported.Objective: Our study was to assess the impact of anxiety on PHT of AMI patients in order to provide a basis for the development of prehospital delay intervention strategies for anxiety-related AMI patients.Methods: In this multi-centered,cross-sectional observational study,we enrolled 265 patients diagnosed with AMI from four hospitals(Tongji Hospital of Tongji University,Tenth People's Hospital of Tongji University,Yangpu Hospital Tongji University,People's Liberation Army No.411 Hospital)in Shanghai from April 2016 to February 2017.Data collection included demographic status,symptoms of AMI onset,decision time,transit time,PHT(the time of symptom onset to the arrival at hospital door).Anxiety was measured with the Generalized Anxiety Disorder-7(GAD-7).Results: The mean PHT of 265 patients was 150.0(70.0,501.0)min.The results of anxiety assessment showed that a total of 104 patients displayed symptoms of anxiety(mild,n=81; moderate,n=16; severe,n=7).We found that patients with anxiety were more likely to display sign of depression,cardiac denial and fear of death(P<0.05).The incidence of feeling of death and dizziness in anxious patients was higher than non-anxious patients(P<0.05).There was no significant difference in decision time,transit time and PHT between anxious and non-anxious patients(P>0.05).PHT and decision time in patients with severe anxiety tended to be longer than those with mild anxiety(P<0.05).There was no significant difference in the transit time of patients with different degrees of anxiety(P>0.05).Conclusion: Patients with AMI and anxiety are more likely to have depression and cardiac denial.In comparison to patients who are mildly anxious,severely anxious patients with AMI might significantly prolong decision time and PHT,which is more likely to cause the miss of the optimal reperfusion period and affect the prognosis
Characterization of biomass and biochar by LDI-FTICRMS - Effect of the laser wavelength and biomass material.
The pyrolysis of the lignocellulosic biomass is a promising process to produce biofuels or green chemicals. Specific analytical methods have to be developed in order to better understand the composition of biomass and of its pyrolysis products and therefore to optimize the design of pyrolysis processes. For this purpose, different biomasses (Douglas and Miscanthus) and one biochar were analyzed by laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry (LDI FT-ICR MS). This method allowed the biomass and biochar to be analyzed without any sample preparation and with a spatial resolution of about 100 μm. The influence of LDI conditions (laser wavelength and laser irradiance) and the nature of the biomass and biochar on the obtained mass spectrum were investigated. The nature and origin of the observed ions highly depended on LDI conditions. In the softest laser-biomass interaction conditions (low laser irradiance), the detected ions were related to the nature of the investigated biomass. Indeed, the main part of the detected species came from the different biomass subunits and was produced by photolysis of covalent bonds. When more severe laser irradiation conditions were used, the obtained mass spectra gathered the ions relative to (i) the chemical components of the investigated samples, (ii) the recombination products of these species in the gas phase after their ejection from the sample surface, and (iii) the compounds produced by laser pyrolysis of the sample. This was expected to be useful to mimic thermal pyrolysis. Graphical Abstract
Prognostic value of improvement endpoints in pulmonary arterial hypertension trials: A COMPERA analysis.
BACKGROUND: The prognostic value of improvement endpoints that have been used in clinical trials of treatments for pulmonary arterial hypertension (PAH) needs to be further investigated. METHODS: Using the COMPERA database, we evaluated the prognostic value of improvements in functional class (FC) and absolute or relative improvements in 6-min walking distance (6MWD) and N-terminal fragment of pro-brain natriuretic peptide (NT-proBNP). In addition, we investigated multicomponent endpoints based on prespecified improvements in FC, 6MWD and NT-proBNP that have been used in recent PAH trials. Finally, we assessed the predictive value of improvements determined by risk stratification tools. The effects of changes from baseline to first follow-up (3-12 months after initiation of PAH therapy) on consecutive survival were determined by Kaplan-Meier analysis with Log-Rank testing and Cox proportional hazard analyses. RESULTS: All analyses were based on 596 patients with newly diagnosed PAH for whom complete data were available at baseline and first follow-up. Improvements in FC were associated with improved survival, whereas absolute or relative improvements in 6MWD had no predictive value. For NT-proBNP, absolute declines conferred no prognostic information while relative declines by ≥35% were associated with better survival. Improvements in multicomponent endpoints were associated with improved survival and the same was found for risk stratification tools. CONCLUSION: While sole improvements in 6MWD and NT-proBNP had minor prognostic relevance, improvements in multicomponent endpoints and risk stratification tools based on FC, 6MWD, and NT-proBNP were associated with improved survival. These tools should be further explored as outcome measures in PAH trials
Prenatal organochlorine pesticides in placentas from Finland: Exposure of male infants born during 1997-2001.
Do heavy metals and metalloids influence the detoxification of organic xenobiotics in plants?
Mixed pollution with trace elements and organic industrial compounds is characteristic for many spill areas and dumping sites. The danger for the environment and human health from such sites is large, and sustainable remediation strategies are urgently needed. Phytoremediation seems to be a cheap and environmentally sound option for the removal of unwanted compounds, and the hyperaccumulation of trace elements and toxic metals is seemingly independent from the metabolism of organic xenobiotics. However, stress reactions, ROS formation and depletion of antioxidants will also cause alterations in xenobiotic detoxification. Here, we investigate the capability of plants to detoxify chlorophenols via glutathione conjugation in a mixed pollution situation. Typha latifolia and Phragmites australis plants for the present study were grown under greenhouse conditions in experimental ponds. A Picea abies L. suspension culture was grown in a growth chamber. Cadmium sulphate, sodium arsenate and lead chloride in concentrations from 10 to 500 A mu M were administered to plants. Enzymes of interest for the present study were: glutathione transferase (GST), glutathione reductase, ascorbate peroxidase and peroxidase. Measurements were performed according to published methods. GST spectrophotometric assays included the model substrates CDNB, DCNB, NBC, NBoC and the herbicide Fluorodifen. Heavy metals lead to visible stress symptoms in higher plants. Besides one long-term experiment of 72 days duration, the present study shows time and concentration-dependent plant alterations already after 24 and 72 h Cd incubation. P. abies spruce cell cultures react to CdSO4 and Na2HAsO4 with an oxidative burst, similar to that observed after pathogen attack or elicitor treatment. Cd application resulted in a reduction in GSH and GSSG contents. When a heavy metal mixture containing Na2HAsO4, CdSO4 and PbCl2 was applied to cultures, both GSH and GSSG levels declined. Incubation with 80 A mu M arsenic alone doubled GSSG values. Based on these results, further experiments were performed in whole plants of cattail and reed, using cadmium in Phragmites and cadmium and arsenic in Typha as inducers of stress. In Phragmites australis, GST activities for CDNB and DCNB were significantly reduced after short-term Cd exposure (24 h). In the same samples, all antioxidant enzymes increased with rising heavy metal concentrations. Typha latifolia rhizome incubation with Cd and As leads to an increase in glutathione reductase and total peroxidase activity and to a decrease in ascorbate peroxidase activity. Measurements of the same enzymes in leaves of the same plants show increased GR activities, but no change in peroxidases. GST conjugation for CDNB was depressed in both cattail rhizomes and leaves treated with Cd. After As application increased, DCNB enzyme activities were detected. T. latifolia and P. australis are powerful species for phytoremediation because they penetrate a large volume of soil with their extensive root and rhizome systems. However, an effective remediation process will depend on active detoxifying enzymes, and also on the availability of conjugation partners, e.g. glutathione and its analogues. Species-specific differences seem to exist between the regulations of primary defence enzymes like SOD, catalase, peroxidases, whereas others prefer to induce the glutathione-dependent enzymes. As long as the pollutant mix encountered is simple and dominated by heavy metals, plant defence might be sufficient. When pollution plumes contain heavy metals and organic xenobiotics at the same time, this means that part of the detoxification capacity, at least of glutathione-conjugating reactions, is withdrawn from the heavy metal front to serve other purposes. In fact, glutathione S-transferases show strong reactions in stressed plants or in the presence of heavy metals. The spruce cell culture was a perfect model system to study short-term responses on heavy metal impact. Overall, and on the canopy level, this inhibitory effect might result in a lower detoxification capacity for organic pollutants and thus interfere with phytoremediation. We present evidence that pollution with heavy metals will interfere with both the oxidative stress defence in plants, and with their ability to conjugate organic xenobiotics. Despite plant-species-dependent differences, the general reactions seem to include oxidative stress and an induction of antioxidative enzymes. Several processes seem to depend on direct binding of heavy metals to enzyme proteins, but effects on transcription are also observed. Induction of xenobiotic metabolism will be obtained at high heavy metal concentrations, when plant stress is elevated. Plants for phytoremediation of complex pollution mixtures have to be selected according to three major issues: uptake/accumulation capacity, antioxidative stress management, and detoxification/binding properties for both the trace elements and the organic xenobiotics. By way of this, it might be possible to speed up the desired remediation process and/or to obtain the desired end products. And, amongst the end products, emphasis should be laid on industrial building materials, biomass for insulation or biogas production, but not for feed and fodder. Each of these attempts would increase the chances for publicly accepted use of phytoremediation and help to cure the environment