Abnormal Splicing of NEDD4 in Myotonic Dystrophy Type 2 Possible Link to Statin Adverse Reactions

Myotonic dystrophy type 2 (DM2) is a multisystemic disorder caused by a (CCTG)n repeat expansion in intron 1 of CNBP. Transcription of the repeats causes a toxic RNA gain of function involving their accumulation in ribonuclear foci. This leads to sequestration of splicing factors and alters pre-mRNA splicing in a range of downstream effector genes, which is thought to contribute to the diverse DM2 clinical features. Hyperlipidemia is frequent in DM2 patients, but the treatment is problematic because of an increased risk of statin-induced adverse reactions. Hypothesizing that shared pathways lead to the increased risk, we compared the skeletal muscle expression profiles of DM2 patients and controls with patients with hyperlipidemia on statin therapy. Neural precursor cell expressed, developmentally downregulated-4 (NEDD4), an ubiquitin ligase, was one of the dysregulated genes identified in DM2 patients and patients with statin-treated hyperlipidemia. In DM2 muscle, NEDD4 mRNA was abnormally spliced, leading to aberrant NEDD4 proteins. NEDD4 was down-regulated in persons taking statins, and simvastatin treatment of C2C12 cells suppressed NEDD4 transcription. Phosphatase and tensin homologue (PTEN), an established NEDD4 target, was increased and accumulated in highly atrophic DM2 muscle fibers. PTEN ubiquitination was reduced in DM2 myofibers, suggesting that the NEDD4-PTEN pathway is dysregulated in DM2 skeletal muscle. Thus, this pathway may contribute to the increased risk of statin-adverse reactions in patients with DM2

Gene Expression Profiling in Tibial Muscular Dystrophy Reveals Unfolded Protein Response and Altered Autophagy

Peer reviewe

Activation and Deactivation of a Robust Immobilized Cp*Ir-Transfer Hydrogenation Catalyst: A Multielement in Situ X-ray Absorption Spectroscopy Study

A highly robust immobilized [Cp*IrCl2]2 precatalyst on Wang resin for transfer hydrogenation, which can be recycled up to 30 times, was studied using a novel combination of X-ray absorption spectroscopy (XAS) at Ir L3-edge, Cl K-edge, and K K-edge. These culminate in in situ XAS experiments that link structural changes of the Ir complex with its catalytic activity and its deactivation. Mercury poisoning and “hot filtration” experiments ruled out leached Ir as the active catalyst. Spectroscopic evidence indicates the exchange of one chloride ligand with an alkoxide to generate the active precatalyst. The exchange of the second chloride ligand, however, leads to a potassium alkoxide–iridate species as the deactivated form of this immobilized catalyst. These findings could be widely applicable to the many homogeneous transfer hydrogenation catalysts with Cp*IrCl substructure

Genome Sequencing and Comparative Transcriptomics of the Model Entomopathogenic Fungi Metarhizium anisopliae and M. acridum

Metarhizium spp. are being used as environmentally friendly alternatives to chemical insecticides, as model systems for studying insect-fungus interactions, and as a resource of genes for biotechnology. We present a comparative analysis of the genome sequences of the broad-spectrum insect pathogen Metarhizium anisopliae and the acridid-specific M. acridum. Whole-genome analyses indicate that the genome structures of these two species are highly syntenic and suggest that the genus Metarhizium evolved from plant endophytes or pathogens. Both M. anisopliae and M. acridum have a strikingly larger proportion of genes encoding secreted proteins than other fungi, while ∼30% of these have no functionally characterized homologs, suggesting hitherto unsuspected interactions between fungal pathogens and insects. The analysis of transposase genes provided evidence of repeat-induced point mutations occurring in M. acridum but not in M. anisopliae. With the help of pathogen-host interaction gene database, ∼16% of Metarhizium genes were identified that are similar to experimentally verified genes involved in pathogenicity in other fungi, particularly plant pathogens. However, relative to M. acridum, M. anisopliae has evolved with many expanded gene families of proteases, chitinases, cytochrome P450s, polyketide synthases, and nonribosomal peptide synthetases for cuticle-degradation, detoxification, and toxin biosynthesis that may facilitate its ability to adapt to heterogenous environments. Transcriptional analysis of both fungi during early infection processes provided further insights into the genes and pathways involved in infectivity and specificity. Of particular note, M. acridum transcribed distinct G-protein coupled receptors on cuticles from locusts (the natural hosts) and cockroaches, whereas M. anisopliae transcribed the same receptor on both hosts. This study will facilitate the identification of virulence genes and the development of improved biocontrol strains with customized properties

New climate models reveal faster and larger increases in Arctic precipitation than previously projected

As the Arctic continues to warm faster than the rest of the planet, evidence mounts that the region is experiencing unprecedented environmental change. The hydrological cycle is projected to intensify throughout the twenty-first century, with increased evaporation from expanding open water areas and more precipitation. The latest projections from the sixth phase of the Coupled Model Intercomparison Project (CMIP6) point to more rapid Arctic warming and sea-ice loss by the year 2100 than in previous projections, and consequently, larger and faster changes in the hydrological cycle. Arctic precipitation (rainfall) increases more rapidly in CMIP6 than in CMIP5 due to greater global warming and poleward moisture transport, greater Arctic amplification and sea-ice loss and increased sensitivity of precipitation to Arctic warming. The transition from a snow- to rain-dominated Arctic in the summer and autumn is projected to occur decades earlier and at a lower level of global warming, potentially under 1.5 °C, with profound climatic, ecosystem and socio-economic impacts

The hyperfine structure of NO(A2Σ+)

Hyperfine quantum beat spectroscopy has been combined with an effective Hamiltonian approach to determine the hyperfine structure of NO(A, v). NO(A, v = 0, N = 1-7, 9 J = 1.5-8.5, F = 0.5-8.5) was produced by pulsed dye laser excitation on the 0-0 band of the NO A2Σ+ ← X2Π transition at wavelengths around 226 nm. The observed line frequencies, along with those reported in previous measurements of NO(A, v = 0,3) have been fitted using a non-linear least-squares program with numerical diagonalization of the Hamiltonian matrix. This enabled us to determine the best obtainable sets of hyperfine parameters for the molecule. The vibrational dependence of the hyperfine parameters is discussed in the light of previous experimental and theoretical work on related systems. © 2012 Elsevier Inc. All rights reserved

Protein level analysis of UPR and ERAD in TMD biopsies.

<p>(A) Western blotting showed HSPA5 increases in two in five samples when compared to controls. (B) Immunoblotting VCP showed an increase in full length VCP in two TMD samples and an extra band (∼70 kDa) just below the full length VCP in a third sample. Bands at approx. 25 kDa (red boxes) are observed in three of the TMD samples. (C) Samples were also blotted with p97D179 antiserum specific for VCP cleaved at D179 and show bands at approx. 25 kDa in three of the same samples. Total protein content is shown by the myosin band in Coomassie blue staining and showed equal sample loading. A graph of the quantification of the VCP cleavage product (25 kDa) signals normalised to the Coomassie myosin band showed a trend towards being increased in TMD in a <i>t-</i>test (<i>P</i> = 0.077).</p

Hierarchal clustering of TMD and control expression profiles.

<p>Clustering of differentially expressed probes using centroid linkage and euclidean similarity in GeneSpring GX v11.0. The expression profiles of TMD (T1–T5) and controls (C1–C5) are represented as a heatmap (blue = low expression, red = high expression). A list of significantly changed probes is in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0090819#pone.0090819.s002" target="_blank">Table S2</a>.</p

Histology and immunohistochemical analysis of TMD muscle biopsies.

<p>(A) Herovici histology staining of TMD muscle sections showing rimmed vacuolar regions within the fibres. (B) Immunohistochemical (IHC) analysis of TMD muscle sections stained for ubiquitin showing localised cytoplasmic ubiquitin containing inclusions in atrophic and rimmed vacuolated fibres and immunoreactivity at the edge of rimmed vacuoles. (C) Autophagosome marker LC3B staining showed strong immunoreactivity within the rimmed vacuolar regions. (D) VCP staining showed immunoreactivity in bodies within a large subset of rimmed vacuoles. (E) p62 staining showed immunoreactivity in rimmed vacuoles and granular immunoreactive dots (shown by an arrow) in an atrophic fibre. (F) Lysosomal protein LAMP2 staining showed no overall increase in rimmed vacuolated fibres. Two separate TMD fibres (A–C and D–F) with rimmed vacuoles in serial sections are shown. Controls of (G) Herovici staining, (H) ubiquitin, (I) LC3B, (J) VCP, (K) p62 and (L) LAMP2 IHC are included for comparison. Sections are from samples TMD 6 and Ctrl 3 in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0090819#pone-0090819-t001" target="_blank">Table 1</a>. Scale bar 50 µm.</p