Ataxin-2 interacts with the DEAD/H-box RNA helicase DDX6 and interferes with P-bodies and stress granules

Tight control of translation is fundamental for eukaryotic cells, and deregulation of proteins implicated contributes to numerous human diseases. The neurodegenerative disorder spinocerebellar ataxia type 2 is caused by a trinucleotide expansion in the SCA2 gene encoding a lengthened polyglutamine stretch in the gene product ataxin-2, which seems to be implicated in cellular RNA-processing pathways and translational regulation. Here, we substantiate a function of ataxin-2 in such pathways by demonstrating that ataxin-2 interacts with the DEAD/H-box RNA helicase DDX6, a component of P-bodies and stress granules, representing cellular structures of mRNA triage. We discovered that altered ataxin-2 levels interfere with the assembly of stress granules and cellular P-body structures. Moreover, ataxin-2 regulates the intracellular concentration of its interaction partner, the poly(A)-binding protein, another stress granule component and a key factor for translational control. Thus, our data imply that the cellular ataxin-2 concentration is important for the assembly of stress granules and P-bodies, which are main compartments for regulating and controlling mRNA degradation, stability, and translation.     

Maternal immunity and mother-to-child transmission of HCV and HIV-1: challenges and recent advances

Human immunodeficiency virus type 1 (HIV-1) and hepatitis C virus (HCV) are two viral pathogens that establish chronic infections in their hosts and that are at present responsible for serious public health problems on a pandemic scale. HIV-1 and HCV can be transmitted from person to person by contact with bodily fluids. Both can also be transmitted from mother to child during the course of pregnancy and childbirth. There are currently no vaccines available to immunize against HIV-1 and HCV infection or to prevent mother-to-child transmission (MTCT), and accessible treatments have significant yet limited efficacy. However, important progresses have been made since the discovery of HCV and HIV-1 : (a) sensitive screening and detection methods have been perfected ; (b) risk factors for acquisition, replicative cycles, pathogenesis, and mechanisms of transmission have been better characterized ; (c) specific treatments, immunotherapy, and antiretroviral prophylaxis regimen were developed ; (d) immune correlates of protection are better understood ; and (e) vaccine design was undertaken. In addition, co-infection with HCV and HIV-1, which is common among high-risk groups including injection drug users, significantly increases the incidence of MTCT of both viruses. The mechanisms by which this facilitation occurs are still under investigation and may involve direct replicative facilitation, enhancement of placental transfer, and/or interference with host immune responses. Taken together, these developments could lead to the implementation of global scale strategies to prevent MTCT of HCV and HIV-1.     

Gene expression variation in Down's syndrome mice allows prioritization of candidate genes

Background  

Down's syndrome (DS), or trisomy 21, is a complex developmental disorder that exhibits many clinical signs that vary in occurrence and severity among patients. The molecular mechanisms responsible for DS have thus far remained elusive. We argue here that normal variation in gene expression in the population contributes to the heterogeneous clinical picture of DS, and we estimated the amplitude of this variation in 50 mouse orthologs of chromosome 21 genes in brain regions of Ts65Dn (a mouse model of DS). We analyzed the RNAs of eight Ts65Dn and eight euploid mice by real-time polymerase chain reaction.     

Soil sampling for <Emphasis Type="Italic">Metarhizium anisopliae</Emphasis> spores in Queensland sugarcane fields

Three sugarcane fields in Bundaberg and four fields in each of the Burdekin, Tully and Innisfail (Queensland, Australia) were sampled for spores of Metarhizium anisopliae (Metchnikoff) (Deuteromycotina: Hyphomycetes). This entomopathogenic fungus is the active ingredient in the biocide “BioCane^TM”, which was developed for the management of the greyback canegrub Dermolepida albohirtum (Waterhosue) (Coleoptera: Scarabaeidae) and other scarabs in cane fields. Fields sampled were of different crop ages and all had a history of BioCane^TM treatment in Plant Cane in past years. Soil samples were taken in each field from four depths (0–10, 10–20, 20–30 and 30–40 cm below soil level) with the use of an auger. Spore levels were highest at the depths of 10–20 and 20–30 cm. Spore levels differed between locations with Innisfail and Tully recording the highest spore counts. Spores were also found in the inter-row space in plots sampled in Tully. Sampling statistics were determined for M. anisopliae spores at the four soil depths with 0.1 and 0.25 precision levels. Three sampling methods were compared (use of marker beads; use of 100 mm auger and 150 mm auger). Samples that relied on marker beads resulted in higher spore counts, however, an auger can still be used since BioCane^TM does not normally contain coloured markers. Results obtained demonstrate the ability of the pathogen to translocate in soil profile and across rows, most likely due to grub movements and other soil fauna. Sampling for M. anisopliae spores provides good monitoring of their levels in soil. The implications of this on grub management decisions are discussed.     

<Emphasis Type="Italic">Tindallia texcoconensis</Emphasis> sp. nov., a new haloalkaliphilic bacterium isolated from lake Texcoco,Mexico

A new alkaliphilic and moderately halophilic, strictly anaerobic, fermentative bacterium (strain IMP-300^T) was isolated from a groundwater sample in the zone of the former soda lake Texcoco in Mexico. Strain IMP-300^T was Gram-positive, non-sporulated, motile and rod-shaped. It grew within a pH range from 7.5 to 10.5, and an optimum at 9.5. The organism was obligately dependent on the presence of sodium salts. Growth showed an optimum at 35°C with absence of growth above 45°C. It fermented peptone and a few amino acids, preferentially arginine and ornithine, with production of acetate, propionate, and ammonium. Its fatty acid pattern was mainly composed of straight chain saturated, unsaturated, and cyclopropane fatty acids. The G + C content of genomic DNA was 40.0 mol%. Analysis of the 16S rRNA gene sequence indicated that the new isolate belongs to the genus Tindallia, in the low G + C Gram-positive phylum. Phylogenetically, strain IMP-300^T has Tindallia californiensis, as closest relative with a 97.5% similarity level between their 16S rDNA gene sequences, but the DNA–DNA re-association value between the two DNAs was only 42.2%. On the basis of differences in genotypic, phenotypic, and phylogenetic characteristics, strain IMP-300^T is proposed as a new species of the genus Tindallia, T. texcoconensis sp. nov. (type strain IMP-300^T = DSM 18041^T = JCM 13990^T).     

Estimation of linear and mass attenuation coefficients of soy–lignin bonded Rhizophora spp. particleboard as a potential phantom material using caesium-137 and cobalt-60

In this study, linear and mass attenuation coefficients of fabricated particleboards intended for use as phantom material were estimated using ¹³⁷Cs and ⁶⁰Co radiation sources. Particleboards made of Rhizophora spp. wood trunk bonded with soy flour and lignin were fabricated at a target density of 1.0 g cm^?3, with and without gloss finish coating. Elemental composition of the particleboards was obtained by means of energy dispersive X-ray (EDX) spectroscopy. Experimental setups were simulated via the GATE Monte Carlo (MC) package, with particle histories of 1?×?10⁶–1?×?10⁷. Linear and mass attenuation coefficients obtained from measurements and GATE simulations were compared and discussed. The percentage differences between the measured and simulated linear and mass attenuation coefficients of the samples were reasonably small (2.05–4.88% for ¹³⁷Cs and 3.24–5.38% for ⁶⁰Co). It is shown that all the particleboards have the potential to be used as phantom materials as the attenuation coefficients measured were in good agreement with those of water (calculated with XCOM) and with those simulated with the GATE toolkit. The use of gloss finish coating also did not show any significant effect on the attenuation coefficient of the phantom material. Verification of experimental results via GATE simulations has been shown crucial in providing reliable data for energy transmission studies. Based on the results achieved in this study, it is concluded that the studied material—Rhizophora spp. wood trunk bonded with soy flour and lignin including gloss finish coating—can be used in radiation dosimetry studies.

     

Tetrahydrobiopterin and Its Multiple Roles in Neuropsychological Disorders

Neurochemical Research - Tetrahydrobiopterin (BH4) is a multifunctional co-factor of various enzymes and a substantial amount of studies have shown BH4 as a key regulator in the synthesis of...     

Peridontitis as a Risk Factor for Attention Deficit Hyperactivity Disorder: Possible Neuro-inflammatory Mechanisms

Periodontitis is a condition caused mostly by the creation of a biofilm by the bacterium P. gingivalis, which releases toxins and damages the tooth structure. Recent research studies have reported association between dental health and neuropsychiatric illnesses. Neuroinflammation triggered by the first systemic inflammation caused by the bacterium present in the oral cavities is a plausible explanation for such a relationship. Substantial amount of evidence supports the role of neuroinflammation and dysfunction of the dopaminergic system in the pathology of ADHD (Attention deficit hyperactivity disorders). Recent epidemiological, microbiological and inflammatory findings strengthen that, periodontal bacteria, which cause systemic inflammation can contribute to neuroinflammation and finally ADHD. Although both diseases are characterized by inflammation, the specific pathways and crosslink’s between periodontitis and ADHD remain unknown. Here, the authors describe the inflammatory elements of periodontitis, how this dental illness causes systemic inflammation, and how this systemic inflammation contributes to deteriorating neuroinflammation in the evolution of ADHD. Therefore, the aim of this review is to present possible links and mechanisms that could confirm the evidence of this association.

     

Untargeted metabolomics reveals differences between commercial and non-commercial Camellia sinensis cultivars used in black tea production

Journal of Plant Biochemistry and Biotechnology - Tea (Camellia sinensis) has enthralled both consumers and researchers, due to its taste, aroma and its medicinal attributes. Tea consumers concern...