Nicotine and the renin-angiotensin system Oakes, Joshua M; Fuchs, Robert M; Gardner, Jason D ...
American journal of physiology. Regulatory, integrative and comparative physiology,
11/2018, Volume:
315, Issue:
5
Journal Article
Peer reviewed
Open access
Cigarette smoking is the single most important risk factor for the development of cardiovascular and pulmonary diseases (CVPD). Although cigarette smoking has been in constant decline since the ...1950s, the introduction of e-cigarettes or electronic nicotine delivery systems 10 yr ago has attracted former smokers as well as a new generation of consumers. Nicotine is a highly addictive substance, and it is currently unclear whether e-cigarettes are "safer" than regular cigarettes or whether they have the potential to reverse the health benefits, notably on the cardiopulmonary system, acquired with the decline of tobacco smoking. Of great concern, nicotine inhalation devices are becoming popular among young adults and youths, emphasizing the need for awareness and further study of the potential cardiopulmonary risks of nicotine and associated products. This review focuses on the interaction between nicotine and the renin-angiotensin system (RAS), one of the most important regulatory systems on autonomic, cardiovascular, and pulmonary functions in both health and disease. The literature presented in this review strongly suggests that nicotine alters the homeostasis of the RAS by upregulating the detrimental angiotensin-converting enzyme (ACE)/angiotensin (ANG)-II/ANG II type 1 receptor axis and downregulating the compensatory ACE2/ANG-(1-7)/Mas receptor axis, contributing to the development of CVPD.
The ribosomal-RNA (rRNA) approach to microbial evolution and ecology has become an integral part of environmental microbiology. Based on the patchy conservation of rRNA, oligonucleotide probes can be ...designed with specificities that range from the species level to the level of phyla or even domains. When these probes are labelled with fluorescent dyes or the enzyme horseradish peroxidase, they can be used to identify single microbial cells directly by fluorescence in situ hybridization. In this Review, we provide an update on the recent methodological improvements that have allowed more reliable quantification of microbial populations in situ in complex environmental samples, with a particular focus on the usefulness of group-specific probes in this era of ever-growing rRNA databases.
Heterotrophic microbial communities process much of the carbon fixed by phytoplankton in the ocean, thus having a critical role in the global carbon cycle. A major fraction of the ...phytoplankton-derived substrates are high-molecular-weight (HMW) polysaccharides. For bacterial uptake, these substrates must initially be hydrolysed to smaller sizes by extracellular enzymes. We investigated polysaccharide hydrolysis by microbial communities during a transect of the Atlantic Ocean, and serendipitously discovered-using super-resolution structured illumination microscopy-that up to 26% of total cells showed uptake of fluorescently labelled polysaccharides (FLA-PS). Fluorescence in situ hybridisation identified these organisms as members of the bacterial phyla Bacteroidetes and Planctomycetes and the gammaproteobacterial genus Catenovulum. Simultaneous membrane staining with nile red indicated that the FLA-PS labelling occurred in the cell but not in the cytoplasm. The dynamics of FLA-PS staining was further investigated in pure culture experiments using Gramella forsetii, a marine member of Bacteroidetes. The staining patterns observed in environmental samples and pure culture tests are consistent with a 'selfish' uptake mechanisms of larger oligosaccharides (>600 Da), as demonstrated for gut Bacteroidetes. Ecologically, this alternative polysaccharide uptake mechanism secures substantial quantities of substrate in the periplasmic space, where further processing can occur without diffusive loss. Such a mechanism challenges the paradigm that hydrolysis of HMW substrates inevitably yields low-molecular-weight fragments that are available to the surrounding community and demonstrates the importance of an alternative mechanism of polysaccharide uptake in marine bacteria.
Sequencing ribosomal RNA (rRNA) genes is currently the method of choice for phylogenetic reconstruction, nucleic acid based detection and quantification of microbial diversity. The ARB software suite ...with its corresponding rRNA datasets has been accepted by researchers worldwide as a standard tool for large scale rRNA analysis. However, the rapid increase of publicly available rRNA sequence data has recently hampered the maintenance of comprehensive and curated rRNA knowledge databases. A new system, SILVA (from Latin silva, forest), was implemented to provide a central comprehensive web resource for up to date, quality controlled databases of aligned rRNA sequences from the Bacteria, Archaea and Eukarya domains. All sequences are checked for anomalies, carry a rich set of sequence associated contextual information, have multiple taxonomic classifications, and the latest validly described nomenclature. Furthermore, two precompiled sequence datasets compatible with ARB are offered for download on the SILVA website: (i) the reference (Ref) datasets, comprising only high quality, nearly full length sequences suitable for in-depth phylogenetic analysis and probe design and (ii) the comprehensive Parc datasets with all publicly available rRNA sequences longer than 300 nucleotides suitable for biodiversity analyses. The latest publicly available database release 91 (August 2007) hosts 547 521 sequences split into 461 823 small subunit and 85 689 large subunit rRNAs.
Post-translational modifications (PTMs) occur on nearly all proteins. Many domains within proteins are modified on multiple amino acid sidechains by diverse enzymes to create a myriad of possible ...protein species. How these combinations of PTMs lead to distinct biological outcomes is only beginning to be understood. This manuscript highlights several examples of combinatorial PTMs in proteins, and describes recent technological developments, which are driving our ability to understand how PTM patterns may “code” for biological outcomes.
Marine sediments are the largest carbon sink on earth. Nearly half of dark carbon fixation in the oceans occurs in coastal sediments, but the microorganisms responsible are largely unknown. By ...integrating the 16S rRNA approach, single-cell genomics, metagenomics and transcriptomics with (14)C-carbon assimilation experiments, we show that uncultured Gammaproteobacteria account for 70-86% of dark carbon fixation in coastal sediments. First, we surveyed the bacterial 16S rRNA gene diversity of 13 tidal and sublittoral sediments across Europe and Australia to identify ubiquitous core groups of Gammaproteobacteria mainly affiliating with sulfur-oxidizing bacteria. These also accounted for a substantial fraction of the microbial community in anoxic, 490-cm-deep subsurface sediments. We then quantified dark carbon fixation by scintillography of specific microbial populations extracted and flow-sorted from sediments that were short-term incubated with (14)C-bicarbonate. We identified three distinct gammaproteobacterial clades covering diversity ranges on family to order level (the Acidiferrobacter, JTB255 and SSr clades) that made up >50% of dark carbon fixation in a tidal sediment. Consistent with these activity measurements, environmental transcripts of sulfur oxidation and carbon fixation genes mainly affiliated with those of sulfur-oxidizing Gammaproteobacteria. The co-localization of key genes of sulfur and hydrogen oxidation pathways and their expression in genomes of uncultured Gammaproteobacteria illustrates an unknown metabolic plasticity for sulfur oxidizers in marine sediments. Given their global distribution and high abundance, we propose that a stable assemblage of metabolically flexible Gammaproteobacteria drives important parts of marine carbon and sulfur cycles.
Summary
Background
Endoscopic band ligation (EBL) is used for primary (PP) and secondary prophylaxis (SP) of variceal bleeding. Current guidelines recommend combined use of non‐selective ...beta‐blockers (NSBBs) and EBL for SP, while in PP either NSBB or EBL should be used.
Aim
To assess (re‐)bleeding rates and mortality in cirrhotic patients receiving EBL for PP or SP for variceal bleeding.
Methods
(Re‐)bleeding rates and mortality were retrospectively assessed with and without concomitant NSBB therapy after first EBL in PP and SP.
Results
Seven hundred and sixty‐six patients with oesophageal varices underwent EBL from 01/2005 to 06/2015. Among the 284 patients undergoing EBL for PP, n = 101 (35.6%) received EBL only, while n = 180 (63.4%) received EBL + NSBBs. In 482 patients on SP, n = 163 (33.8%) received EBL only, while n = 299 (62%) received EBL + NSBBs. In PP, concomitant NSBB therapy neither decreased bleeding rates (log‐rank: P = 0.353) nor mortality (log‐rank: P = 0.497) as compared to EBL alone. In SP, similar re‐bleeding rates were documented in EBL + NSBB vs EBL alone (log‐rank: P = 0.247). However, EBL + NSBB resulted in a significantly lower mortality rate (log‐rank: P<0.001). A decreased risk of death with EBL + NSBB in SP (hazard ratio, HR: 0.50; P<0.001) but not of rebleeding, transplantation or further decompensation was confirmed by competing risk analysis. Overall NSBB intake reduced 6‐months mortality (HR: 0.53, P = 0.008) in SP, which was most pronounced in patients without severe/refractory ascites (HR: 0.37; P = 0.001) but not observed in patients with severe/refractory ascites (HR: 0.80; P = 0.567).
Conclusions
EBL alone seems sufficient for PP of variceal bleeding. In SP, the addition of NSBB to EBL was associated with an improved survival within the first 6 months after EBL.
Linked ContentThis article is linked to Bosch and Berzigotti and Pfisterer et al papers. To view these articles visit https://doi.org/10.1111/apt.14546 and https://doi.org/10.1111/apt.14581.
Access to high-quality antibodies is a necessity for the study of histones and their posttranslational modifications (PTMs). Here we debut the Histone Antibody Specificity Database ...(http://www.histoneantibodies.com), an online and expanding resource cataloging the behavior of widely used, commercially available histone antibodies by peptide microarray. This interactive web portal provides a critical resource to the biological research community that routinely uses these antibodies as detection reagents for a wide range of applications.
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•Peptide microarrays catalog the specificity of widely used histone antibodies•Histone antibodies frequently show difficulties in detecting their intended targets•A Histone Antibody Specificity Database (http://www.histoneantibodies.com) was created•This resource facilitates more informed antibody choice for epigenetic applications
Rothbart et al. use a recently developed histone peptide microarray platform to analyze the specificities of over 100 commercially available and widely used antibodies against histone posttranslational modifications. A publicly available database that is interactive and is designed to expand through user participation has been created, http://www.histoneantibodies.com.
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