Cigarette Smoke Upregulates Rat Coronary Artery Endothelin Receptors In Vivo

Background: Cigarette smoking is a strong cardiovascular risk factor and endothelin (ET) receptors are related to coronary artery diseases. The present study established an in vivo secondhand smoke (SHS) exposure model and investigated the hypothesis that cigarette smoke induces ET receptor upregulation in rat coronary arteries and its possible underlying mechanisms. Methodology/Principal Findings: Rats were exposed to SHS for 200 min daily for 8 weeks. The coronary arteries were isolated and examined. The vasoconstriction was studied by a sensitive myograph. The expression of mRNA and protein for receptors was examined by real-time PCR, Western blot and immunofluorescence. Compared to fresh air exposure, SHS increased contractile responses mediated by endothelin type A (ETA) and type B (ETB) receptors in coronary arteries. In parallel, the expression of mRNA and protein for ETA and ETB receptors of smoke exposed rats were higher than that of animals exposed to fresh air, suggesting that SHS upregulates ET A and ET B receptors in coronary arteries in vivo. Immunofluorescence staining showed that the enhanced receptor expression was localized to the smooth muscle cells of coronary arteries. The protein levels of phosphorylated (p)-Raf-1 and p-ERK1/2 in smoke exposed rats were significantly higher than in control rats, demonstrating that SHS induces the activation of the Raf/ERK/MAPK pathway. Treatment with Raf-1 inhibitor GW5074 suppressed SHS-induced enhanced contraction mediated by ET A receptors, and inhibited th

The 3-Base Periodicity and Codon Usage of Coding Sequences Are Correlated with Gene Expression at the Level of Transcription Elongation

Background: Gene transcription is regulated by DNA transcriptional regulatory elements, promoters and enhancers that are located outside the coding regions. Here, we examine the characteristic 3-base periodicity of the coding sequences and analyse its correlation with the genome-wide transcriptional profile of yeast. Principal Findings: The analysis of coding sequences by a new class of indices proposed here identified two different sources of 3-base periodicity: the codon frequency and the codon sequence. In exponentially growing yeast cells, the codon-frequency component of periodicity accounts for 71.9 % of the variability of the cellular mRNA by a strong association with the density of elongating mRNA polymerase II complexes. The mRNA abundance explains most of the correlation between the codon-frequency component of periodicity and protein levels. Furthermore, pyrimidine-ending codons of the four-fold degenerate small amino acids alanine, glycine and valine are associated with genes with double the transcription rate of those associated with purine-ending codons. Conclusions: We demonstrate that the 3-base periodicity of coding sequences is higher than expected by the codon usage frequency (CUF) and that its components, associated with codon bias and amino acid composition, are correlated with gene expression, principally at the level of transcription elongation. This indicates a role of codon sequences in maximising the transcription efficiency in exponentially growing yeast cells. Moreover, the results contrast with the common Darwinia

Preclinical carotid atherosclerosis in patients with latent autoimmune diabetes in adults (LADA), type 2 diabetes and classical type 1 diabetes

This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.This project was funded by Grants Nos. PI12/00183 and PI15/00625, both included in Plan Nacional de I + D + I, and co-financed by Instituto de Salud Carlos III, Subdireccion General de Evaluacion, Ministry of Economy and Competitiveness, and Fondo Europeo de Desarrollo Regional (FEDER). CIBER of Diabetes and Associated Metabolic Diseases (CIBERDEM) is an initiative from Instituto de Salud Carlos III, Spain

Synonymous but not the same: the causes and consequences of codon bias

Despite their name, synonymous mutations have significant consequences for cellular processes in all taxa. As a result, an understanding of codon bias is central to fields as diverse as molecular evolution and biotechnology. Although recent advances in sequencing and synthetic biology have helped resolve longstanding questions about codon bias, they have also uncovered striking patterns that suggest new hypotheses about protein synthesis. Ongoing work to quantify the dynamics of initiation and elongation is as important for understanding natural synonymous variation as it is for designing transgenes in applied contexts

Afgrøde og ukrudt konkurrerer om kvælstof

Udbringningsmetoden for gylle påvirker konkurrencen mellem afgrøde og ukrudt om tilført kvælstof. Ved bredspredning af gødningen kan ukrudtet optage en betydelig del af den tilførte gødning, og dermed bliver ukrudtet en konkurrent til afgrøden. Forholdet i ukrudt/afgrøde konkurrencen om den tilførte gødning kan forskydes til afgrødens fordel ved direkte nedfældning af gødningen. I dette års forsøg undersøges hvilken betydning afstanden mellem kornrækken og gødningsstrengen har for konkurrence mellem afgrøde og ukrudt om tilført kvælstof. Der er udvalgt en vårsæds-mark med en høj naturlig ukrudtsbestand. Den lille parcelstørrelse (30?40 cm) skyldes, at den tilførte gylle er tilsat isotopmærket kvælstof. Herved er det muligt at beregne, hvor stor en andel af det tilførte kvælstof afgrøden henholdsvis ukrudtet optager

Upregulation of endothelin ETB receptor-mediated vasoconstriction in rat coronary artery after organ culture

The aim of this study was to examine if endothelin ETB receptor-mediated contraction occurred in isolated segments of rat coronary arteries during organ culture. Presence of contractile endothelin ETB receptors was studied by measuring the change in isometric tension in rings of left anterior descending coronary arteries isolated from hearts of rats as response to application of the selective endothelin ETB receptor agonist, Sarafotoxin 6c and endothelin-1. In segments cultured 1 day in serum free Dulbecco's Modified Eagle's Medium, Sarafotoxin 6c induced a concentration dependent contraction with pEC(50) value of 10.4 +/- 0.21 and a maximal response of 3.9 +/- 0.25 mN/mm (n = 15). The maximal contraction was significantly larger than the responses measured in fresh tissue, where the mean value of the maximal contractions was 0.22 +/- 0.03 mN/mm (n = 17). The increased contraction to Sarafotoxin 6c, after culturing could be eliminated with addition of the transcriptional blocker, actinomycin D, to the culture medium or be significantly attenuated by application of the translational inhibitor, cycloheximide. The vasoconstrictor effect of endothelin-1 or to depolarisation by high K+-solution was not modified after 1 day in culture medium. The experiments indicate that organ culture of rat coronary arteries upregulate endothelin ETB receptor-mediated contraction by inducing synthesis of new protein. (c) 2006 Elsevier B.V. All rights reserved