bluuebunny/crossref_metadata_2025 huggingface dataset:
USP15 targets ALK3/BMPR1A for deubiquitylation to enhance bone morphogenetic protein signalling
Authors: Herhaus Lina , Al-Salihi Mazin A. , Dingwell Kevin S. , Cummins Timothy D. , Wasmus Lize , Vogt Janis , Ewan Richard , Bruce David , Macartney Thomas , Weidlich Simone , Smith James C. , Sapkota Gopal P.
Published: May 2014

Protein kinase ALK3/BMPR1A mediates bone morphogenetic protein (BMP) signalling through phosphorylation and activation of SMADs 1/5/8. SMAD6, a transcriptional target of BMP, negatively regulates the BMP pathway by recruiting E3 ubiquitin ligases and targeting ALK3 for ubiquitin-mediated degradation. Here, we identify a deubiquitylating enzyme USP15 as an interactor of SMAD6 and ALK3. We show that USP15 enhances BMP-induced phosphorylation of SMAD1 by interacting with and deubiquitylating ALK3.
RNAi
-mediated depletion of USP15 increases ALK3 K48-linked polyubiquitylation, and reduces both BMP-induced SMAD1 phosphorylation and transcription of BMP target genes. We also show that loss of USP15 expression from mouse myoblast cells inhibits BMP-induced osteoblast differentiation. Furthermore, USP15 modulates BMP-induced phosphorylation of SMAD1 and transcription during
Xenopus
embryogenesis.
Conyzicola lurida gen. nov., sp. nov., isolated from the root of Conyza canadensis
Authors: Kim Tae-Su , Han Ji-Hye , Joung Yochan , Kim Seung Bum
Published: May 2014

A novel Gram-stain-positive, non-spore-forming, pale yellow, irregular rod-shaped bacterium designated strain HWE2-01T was isolated from the surface-sterilized root of horseweed (Conyza canadensis). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain HWE2-01T belongs to the family

Microbacteriaceae

and showed sequence similarity levels of 97.1–97.7 % with species of the genus

Salinibacterium

, 95.9–97.6 % with species of the genus

Leifsonia

and 97.1 % with

Homoserinimonas aerilata

. The highest sequence similarity (97.7 %) was with

Salinibacterium xinjiangense

0543T. The genomic DNA G+C content of the novel strain was 68.1 mol%. The predominant cellular fatty acid of strain HWE2-01T was anteiso-C15 : 0, major menaquinones were MK-10, MK-9 and MK-11, and diagnostic polar lipids were diphosphatidylglycerol and phosphatidylglycerol. The peptidoglycan of the novel strain contained 2,4-diaminobutyric acid, alanine, glycine and glutamic acid. The cell-wall sugars of strain HWE2-01T were galactose, mannose and rhamnose. The murein was of the acetyl type. Based on the results of the phenotypic and phylogenetic analysis, strain HWE2-01T differed in some respects from other members of the family

Microbacteriaceae

. Therefore, strain HWE2-01T is proposed to represent a novel species of a new genus in the family

Microbacteriaceae

with the name Conyzicola lurida gen. nov., sp. nov. (type strain = HWE2-01T = KCTC 29231T = JCM 19257T).
Bacillus
oryzaecorticis sp. nov., a moderately halophilic bacterium isolated from rice husks
Authors: Hong Sung Wook , Kwon Soon-Wo , Kim Soo-Jin , Kim Song Yi , Kim Jong Jin , Lee Jong Sung , Oh Mi-Hwa , Kim Ae-Jung , Chung Kun Sub
Published: May 2014

A Gram-stain-positive, aerobic, endospore-forming, moderately halophilic rod, designated strain R1T, was isolated from rice husks and subjected to a taxonomic study using a polyphasic approach. Strain R1T produced spherical or ellipsoidal endospores at a subterminal position in swollen sporangia, and was catalase- and oxidase-positive. The isolate grew optimally at 37 °C and pH 6.0–7.0, and could grow in the presence of up to 9 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain R1T belongs to the genus

Bacillus

. The closest relatives of strain R1T were

Bacillus subtilis subsp. subtilis

NCIB 3610T,

Bacillus aquimaris

TF-12T, and

Bacillus marisflavi

TF-11T, with 16S rRNA gene sequence similarities of 96.0 %, 98.4 %, and 98.7 %, respectively. DNA–DNA relatedness values between the isolate and the reference strains were ≤42±3 %. The predominant menaquinones were MK-5 (50 %) and MK-7 (50 %). The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol, and phosphatidylethanolamine. The major cellular fatty acids were iso-C15 : 0 (48.6 %) and anteiso-C15 : 0 (20.6 %), and the cell-wall diamino acid was meso-diaminopimelic acid. On the basis of 16S rRNA gene sequence analyses and chemotaxonomic and phenotypic characteristics, it is concluded that strain R1T represents a novel species of the genus

Bacillus

, for which we propose the name Bacillus oryzaecorticis sp. nov. The type strain is R1T ( = KACC 17217T = KCCM 90231T = JCM 19602T).
Spirochaeta psychrophila sp. nov., a psychrophilic spirochaete isolated from subseafloor sediment, and emended description of the genus Spirochaeta
Authors: Miyazaki Masayuki , Sakai Sanae , Yamanaka Yuko , Saito Yumi , Takai Ken , Imachi Hiroyuki
Published: May 2014

An obligately anaerobic, psychrophilic spirochaete, strain MO-SPC1T, was isolated from a methanogenic microbial community grown in a continuous-flow bioreactor. Originally, this community was obtained from subseafloor sediments off the Shimokita Peninsula of Japan in the north-western Pacific Ocean. The cells were motile, Gram-stain-negative, helical, 0.25–0.55×3.6–15 µm, with a wavelength of approximately 0.5–0.6 µm. Strain MO-SPC1T grew at 0–18 °C (optimally at 15 °C), at pH 6.0–7.5 (optimally at pH 6.8–7.0) and in 20–70 g NaCl l−1 (optimally at 30–40 NaCl l−1). The strain grew chemo-organotrophically with mono-, di- and polysaccharides. The major end products of glucose fermentation were acetate, ethanol, hydrogen and carbon dioxide. The abundant polar lipids of strain MO-SPC1T were diphosphatidylglycerol, phosphatidylglycerol, unknown phospholipids and an unknown lipid. The major cellular fatty acids (>5 % of the total) were C14 : 0, C16 : 0, iso-C13 : 0, iso-C14 : 0, iso-C15 : 0, anteiso-C13 : 0 and anteiso-C15 : 0. To the best of our knowledge, this is the first report of the fatty acids iso-C13 : 0 and anteiso-C13 : 0 from a species of the genus

Spirochaeta

. Isoprenoid quinones were not found. The G+C content of the genomic DNA was 39.8 mol%. 16S rRNA gene sequence-based phylogenetic analysis showed that strain MO-SPC1T was affiliated with the genus

Spirochaeta

, and its closest relatives were

Spirochaeta isovalerica

MA-2T (95.6 % sequence identity) and

Spirochaeta litoralis

R1T (89.4 %). Based on its phenotypic characteristics and phylogenetic traits, strain MO-SPC1T is placed in a separate taxon at the level of a novel species within the genus

Spirochaeta,
for which the name Spirochaeta psychrophila sp. nov. is proposed, reflecting its true psychrophilic physiology. The type strain is MO-SPC1T ( = JCM 17280T = DSM 23951T). To our knowledge, this is the first report of an isolate of the phylum

Spirochaetes

from a deep-sea sedimentary environment, and of an obligately psychrophilic nature.
Paracoccus lutimaris sp. nov., isolated from a tidal flat sediment
Authors: Jung Yong-Taek , Park Sooyeon , Lee Jung-Sook , Yoon Jung-Hoon
Published: May 2014

A Gram-negative, coccoid or oval-shaped and gliding bacterial strain, designated HDM-25T, belonging to the

Alphaproteobacteria

, was isolated from a tidal flat sediment of the Yellow Sea, Korea, and was subjected to a polyphasic taxonomic study. Strain HDM-25T grew optimally at pH 7.0–8.0, at 30 °C and in the presence of 2–3 % (w/v) NaCl. Neighbour-joining, maximum-likelihood and maximum-parsimony phylogenetic trees based on 16S rRNA gene sequences showed that strain HDM-25T fell within the clade comprising the species of the genus

Paracoccus

, clustering with the type strain of

Paracoccus aminophilus

, with which it exhibited the highest 16S rRNA gene sequence similarity (97.7 %). The 16S rRNA gene sequence similarity between strain HDM-25T and the type strains of the other species of

Paracoccus

was 93.6–97.0 %. The DNA G+C content was 65.9 mol% and the mean DNA–DNA relatedness between strain HDM-25T and the type strain of

P. aminophilus

was 10.7±2.7 % (9.9±4.0 %, reciprocal analysis). Strain HDM-25T contained Q-10 as the predominant ubiquinone and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C16 : 0 as the major fatty acids. The major polar lipids were phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, an unidentified aminolipid, an unidentified glycolipid and an unidentified lipid. Differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, demonstrated that strain HDM-25T is distinguishable from other species of the genus

Paracoccus

. On the basis of the data presented, strain HDM-25T is considered to represent a novel species of the genus

Paracoccus

, for which the name Paracoccus lutimaris sp. nov. is proposed. The type strain is HDM-25T ( = KCTC 42007T = CECT 8525T).
A Zinc Finger Protein Regulates Flowering Time and Abiotic Stress Tolerance in Chrysanthemum by Modulating Gibberellin Biosynthesis
Authors: Yang Yingjie , Ma Chao , Xu Yanjie , Wei Qian , Imtiaz Muhammad , Lan Haibo , Gao Shan , Cheng Lina , Wang Meiyan , Fei Zhangjun , Hong Bo , Gao Junping
Published: May 2014

Flowering time and an ability to tolerate abiotic stresses are important for plant growth and development. We characterized BBX24, a zinc finger transcription factor gene, from Chrysanthemum morifolium and found it to be associated with both flowering time and stress tolerance. Transgenic lines with suppressed expression of Cm-BBX24 (Cm-BBX24-RNAi) flowered earlier than wild-type plants and showed decreased tolerance to freezing and drought stresses. Global expression analysis revealed that genes associated with both photoperiod and gibberellin (GA) biosynthesis pathways were upregulated in Cm-BBX24-RNAi lines, relative to the wild type. By contrast, genes that were upregulated in overexpressing lines (Cm-BBX24-OX), but downregulated in Cm-BBX24-RNAi lines (both relative to the wild type), included genes related to compatible solutes and carbohydrate metabolism, both of which are associated with abiotic stress. Cm-BBX24 expression was also influenced by daylength and GA4/7 application. Under long days, changes in endogenous GA1, GA4, GA19, and GA20 levels occurred in young leaves of transgenic lines, relative to the wild type. Regulation of flowering involves the FLOWERING TIME gene, which integrates photoperiod and GA biosynthesis pathways. We postulate that Cm-BBX24 plays a dual role, modulating both flowering time and abiotic stress tolerance in chrysanthemum, at least in part by influencing GA biosynthesis.
SAUR Inhibition of PP2C-D Phosphatases Activates Plasma Membrane H+-ATPases to Promote Cell Expansion inArabidopsis
Authors: Spartz Angela K. , Ren Hong , Park Mee Yeon , Grandt Kristin N. , Lee Sang Ho , Murphy Angus S. , Sussman Michael R. , Overvoorde Paul J. , Gray William M.
Published: May 2014

The plant hormone auxin promotes cell expansion. Forty years ago, the acid growth theory was proposed, whereby auxin promotes proton efflux to acidify the apoplast and facilitate the uptake of solutes and water to drive plant cell expansion. However, the underlying molecular and genetic bases of this process remain unclear. We have previously shown that the SAUR19-24 subfamily of auxin-induced SMALL AUXIN UP-RNA (SAUR) genes promotes cell expansion. Here, we demonstrate that SAUR proteins provide a mechanistic link between auxin and plasma membrane H+-ATPases (PM H+-ATPases) in Arabidopsis thaliana. Plants overexpressing stabilized SAUR19 fusion proteins exhibit increased PM H+-ATPase activity, and the increased growth phenotypes conferred by SAUR19 overexpression are dependent upon normal PM H+-ATPase function. We find that SAUR19 stimulates PM H+-ATPase activity by promoting phosphorylation of the C-terminal autoinhibitory domain. Additionally, we identify a regulatory mechanism by which SAUR19 modulates PM H+-ATPase phosphorylation status. SAUR19 as well as additional SAUR proteins interact with the PP2C-D subfamily of type 2C protein phosphatases. We demonstrate that these phosphatases are inhibited upon SAUR binding, act antagonistically to SAURs in vivo, can physically interact with PM H+-ATPases, and negatively regulate PM H+-ATPase activity. Our findings provide a molecular framework for elucidating auxin-mediated control of plant cell expansion.
Structure and mechanism of a nonhaem-iron SAM-dependentC-methyltransferase and its engineering to a hydratase and anO-methyltransferase
Authors: Zou Xiao-Wei , Liu Yu-Chen , Hsu Ning-Shian , Huang Chuen-Jiuan , Lyu Syue-Yi , Chan Hsiu-Chien , Chang Chin-Yuan , Yeh Hsien-Wei , Lin Kuan-Hung , Wu Chang-Jer , Tsai Ming-Daw , Li Tsung-Lin
Published: May 2014

In biological systems, methylation is most commonly performed by methyltransferases (MTs) using the electrophilic methyl sourceS-adenosyl-L-methionine (SAM)viathe SN2 mechanism. (2S,3S)-β-Methylphenylalanine, a nonproteinogenic amino acid, is a building unit of the glycopeptide antibiotic mannopeptimycin. The gene product ofmppJfrom the mannopeptimycin-biosynthetic gene cluster is the MT that methylates the benzylic C atom of phenylpyruvate (Ppy) to give βMePpy. Although the benzylic C atom of Ppy is acidic, how its nucleophilicity is further enhanced to become an acceptor forC-methylation has not conclusively been determined. Here, a structural approach is used to address the mechanism of MppJ and to engineer it for new functions. The purified MppJ displays a turquoise colour, implying the presence of a metal ion. The crystal structures reveal MppJ to be the first ferric ion SAM-dependent MT. An additional four structures of binary and ternary complexes illustrate the molecular mechanism for the metal ion-dependent methyltransfer reaction. Overall, MppJ has a nonhaem iron centre that bind, orients and activates the α-ketoacid substrate and has developed a sandwiched bi-water device to avoid the formation of the unwanted reactive oxo-iron(IV) species during theC-methylation reaction. This discovery further prompted the conversion of the MT into a structurally/functionally unrelated new enzyme. Through stepwise mutagenesis and manipulation of coordination chemistry, MppJ was engineered to perform both Lewis acid-assisted hydration and/orO-methyltransfer reactions to give stereospecific new compounds. This process was validated by six crystal structures. The results reported in this study will facilitate the development and design of new biocatalysts for difficult-to-synthesize biochemicals.
Structure of the phosphotransferase domain of the bifunctional aminoglycoside-resistance enzyme AAC(6′)-Ie-APH(2′′)-Ia
Authors: Smith Clyde A. , Toth Marta , Bhattacharya Monolekha , Frase Hilary , Vakulenko Sergei B.
Published: May 2014

The bifunctional acetyltransferase(6′)-Ie-phosphotransferase(2′′)-Ia [AAC(6′)-Ie-APH(2′′)-Ia] is the most important aminoglycoside-resistance enzyme in Gram-positive bacteria, conferring resistance to almost all known aminoglycoside antibiotics in clinical use. Owing to its importance, this enzyme has been the focus of intensive research since its isolation in the mid-1980s but, despite much effort, structural details of AAC(6′)-Ie-APH(2′′)-Ia have remained elusive. The structure of the Mg2GDP complex of the APH(2′′)-Ia domain of the bifunctional enzyme has now been determined at 2.3 Å resolution. The structure of APH(2′′)-Ia is reminiscent of the structures of other aminoglycoside phosphotransferases, having a two-domain architecture with the nucleotide-binding site located at the junction of the two domains. Unlike the previously characterized APH(2′′)-IIa and APH(2′′)-IVa enzymes, which are capable of utilizing both ATP and GTP as the phosphate donors, APH(2′′)-Ia uses GTP exclusively in the phosphorylation of the aminoglycoside antibiotics, and in this regard closely resembles the GTP-dependent APH(2′′)-IIIa enzyme. In APH(2′′)-Ia this GTP selectivity is governed by the presence of a `gatekeeper' residue, Tyr100, the side chain of which projects into the active site and effectively blocks access to the adenine-binding template. Mutation of this tyrosine residue to a less bulky phenylalanine provides better access for ATP to the NTP-binding template and converts APH(2′′)-Ia into a dual-specificity enzyme.
A copper(I) coordination polymer incorporation the corrosion inhibitor 1H-benzotriazole: poly[μ3-benzotriazolato-κ3N1:N2:N3-copper(I)]
Authors: Liu Jian-Jun , Li Zuo-Yin , Yuan Xiong , Wang Yao , Huang Chang-Cang
Published: May 2014

The title complex, [Cu(C6H4N3)]n, was synthesized by the reaction of cupric nitrate, 1H-benzotriazole (BTAH) and aqueous ammonia under hydrothermal conditions. The asymmetric unit contains three crystallographically independent CuIcations and two 1H-benzotriazolate ligands. Two of the CuIcations, one with a linear two-coordinated geometry and one with a four-coordinated tetrahedral geometry, are located on sites with crystallographically imposed twofold symmetry. The third CuIcation, with a planar three-coordinated geometry, is on a general position. Two CuIcations are doubly bridged by two BTA−ligands to afford a noncentrosymmetric planar [Cu2(BTA)2] subunit, and two [Cu2(BTA)2] subunits are arranged in an antiparallel manner to form a centrosymmetric [Cu2(BTA)2]2secondary building unit (SBU). The SBUs are connected in a crosswise mannerviathe sharing of four-coordinated CuIcations, Cu—N bonding and bridging by two-coordinate CuIcations, resulting in a one-dimensional chain along thecaxis. These one-dimensional chains are further linked by C—H...π and weak van der Waals interactions to form a three-dimensional supramolecular architecture.
Preliminary time-of-flight neutron diffraction studies ofEscherichia coliABC transport receptor phosphate-binding protein at the Protein Crystallography Station
Authors: Sippel K. H. , Bacik J. , Quiocho F. A. , Fisher S. Z.
Published: May 2014

Inorganic phosphate is an essential molecule for all known life. Organisms have developed many mechanisms to ensure an adequate supply, even in low-phosphate conditions. In prokaryotes phosphate transport is instigated by the phosphate-binding protein (PBP), the initial receptor for the ATP-binding cassette (ABC) phosphate transporter. In the crystal structure of the PBP–phosphate complex, the phosphate is completely desolvated and sequestered in a deep cleft and is bound by 13 hydrogen bonds: 12 to protein NH and OH donor groups and one to a carboxylate acceptor group. The carboxylate plays a key recognition role by accepting a phosphate hydrogen. PBP phosphate affinity is relatively consistent across a broad pH range, indicating the capacity to bind monobasic (H2PO4−) and dibasic (HPO42−) phosphate; however, the mechanism by which it might accommodate the second hydrogen of monobasic phosphate is unclear. To answer this question, neutron diffraction studies were initiated. Large single crystals with a volume of 8 mm3were grown and subjected to hydrogen/deuterium exchange. A 2.5 Å resolution data set was collected on the Protein Crystallography Station at the Los Alamos Neutron Science Center. Initial refinement of the neutron data shows significant nuclear density, and refinement is ongoing. This is the first report of a neutron study from this superfamily.
Protein expression, characterization, crystallization and preliminary X-ray crystallographic analysis of a Fic protein fromClostridium difficile
Authors: Welner Ditte , Dedic Emil , van Leeuwen Hans C. , Kuijper Ed , Bjerrum Morten Jannik , Østergaard Ole , Jørgensen René
Published: May 2014

Fic domains in proteins are found in abundance in nature from the simplest prokaryotes to animals. Interestingly, Fic domains found in two virulence factors of Gram-negative bacteria have recently been demonstrated to catalyse the transfer of the AMP moiety from ATP to small host GTPases. This post-translational modification has attracted considerable interest and a role for adenylylation in pathology and physiology is emerging. This work was aimed at the structural characterization of a newly identified Fic protein of the Gram-positive bacteriumClostridium difficile. A constitutively active inhibitory helix mutant ofC. difficileFic was overexpressed inEscherichia coli, purified and crystallized by the vapour-diffusion technique. Preliminary X-ray crystallographic analysis shows that the crystals diffract to at least 1.68 Å resolution at a synchrotron X-ray source. The crystals belonged to the orthorhombic space groupP212121, with unit-cell parametersa= 45.6,b= 80.8,c= 144.7 Å, α = β = γ = 90°. Two molecules per asymmetric unit corresponds to a Matthews coefficient of 2.37 Å3 Da−1and a solvent content of 48%.
Habitat‐specific effectiveness of feral cat control for the conservation of an endemic ground‐nesting bird species
Authors: Oppel Steffen , Burns Fiona , Vickery Juliet , George Kevin , Ellick Gavin , Leo Dennis , Hillman Jesse C.
Published: May 2014

Invasive non‐native species are one of the greatest drivers of the loss of biodiversity world‐wide. Consequently, removing or controlling invasive predators should generally benefit vulnerable native species. However, especially on islands, where most mammalian predators are introduced, these predators may also prey on other invasive mammals. Removing only apex predators may lead to increases of meso‐predators that may in turn increase predation pressure on native wildlife.

We examined the benefits of a feral cat Felis catus control programme on nest survival of a critically endangered ground‐nesting bird, the St Helena Plover Charadrius sanctaehelenae in two habitat types, harbouring c. 30% of the global population of this species. We monitored nest success and the activity of introduced mammals (cats, rabbits Oryctolagus cuniculus, rats Rattus rattus and Rattus norvegicus, and mice Mus musculus) over 2 years, before and after controlling feral cats.

Live trapping removed 56 feral cats from our study areas. In the semi‐desert, rabbit and mouse activity increased, but rat activity remained low after feral cat control. In pastures, rat and mouse activity increased after feral cat control, while rabbit activity remained constant.

Nest survival of plovers increased more than threefold in the semi‐desert, but increased only marginally in pastures. This difference may be due to an increase in rat activity and potentially rat predation following cat control in pastures, whereas no increase in rat activity was observed in the semi‐desert.

Synthesis and applications. Our study shows habitat‐specific consequences of feral cat control on ground‐nesting bird productivity after 1 year, probably mediated by differences in the availability of alternative prey. The results highlight the importance of experimental trials and a thorough understanding of the interactions between multiple invasive species before predator‐control operations are implemented over larger scales. On islands with multiple invasive species, there may not be a simple generic approach to predator management (other than removing all invasive species simultaneously).
Dual effects of amiodarone on pacemaker currents in hypertrophied ventricular myocytes isolated from spontaneously hypertensive rats
Authors: Li Hongxia , Zhou Yafeng , Jiang Bin , Zhao Xin , Li Xun , Yang Xiangjun , Jiang Wenping
Published: May 2014

The pacemaker current If conducted by hyperpolarization‐activated cyclic nucleotide‐gated (HCN) channels plays a critical role in the regulation of cardiac automaticity, with If density increased in hypertrophied ventricular myocytes. Amiodarone, a highly effective anti‐arrhythmic agent, blocks human HCN currents and native If under normal conditions. To determine the effects of amiodarone under pathological conditions, we monitored If under after both acute (0.01, 0.1, 1, 10 and 100 μmol/L) and chronic (10 μmol/L) amiodarone treatment in ventricular myocytes from spontaneously hypertensive rats (SHR) with left ventricular hypertrophy using the whole‐cell patch‐clamp technique. The If current density was significantly greater in SHR ventricular myocytes than in cells from healthy normotensive control Wistar‐Kyoto (WKY) rats. Acute application of amiodarone significantly decreased If density in myocytes from both SHR and WKY rats. The inhibition was concentration dependent with an IC50 of 4.9 ± 1.2 and 6.9 ± 1.3 μmol/L in myocytes from SHR and WKY rats, respectively. Amiodarone increased the activation and deactivation times of If in myocytes from SHR, although it did not alter the relationship of voltage‐dependent activation and the reversal potential of If in myocytes from SHR. Chronic exposure of myocytes from SHR to amiodarone potently inhibited If and downregulated HCN2 and HCN4, the major channel subtypes underlying native If, at both the mRNA and protein level. These findings indicate that amiodarone inhibits If under hypertrophied conditions through dual mechanisms: (i) direct channel blockade of If currents; and (ii) indirect suppression via negative regulation of HCN channel gene expression. These unique properties of amiodarone may contribute to its anti‐arrhythmic properties under pathological conditions.
Metformin may produce antidepressant effects through improvement of cognitive function among depressed patients with diabetes mellitus
Authors: Guo Min , Mi Jia , Jiang Qiu‐Ming , Xu Jin‐Mei , Tang Ying‐Ying , Tian Geng , Wang Bin
Published: May 2014

Diabetes mellitus and depressive disorders are both common chronic diseases that increase functional disability and social burden. Cognitive impairment is a potentially debilitating feature of depression. Previous evidence indicates that the antidiabetic drug metformin could be suitable for diabetic patients with cognitive impairment. However, there is no direct evidence from clinical studies that metformin treatment improves cognitive function in diabetic patients suffering from depression. In the present study, 58 participants diagnosed with depression and type 2 diabetes mellitus (T2DM) were recruited and divided into two groups, one treated with metformin and the other treated with placebo for 24 weeks. Cognitive function, depressive behaviour and diabetes improvement were evaluated. Chronic treatment with metformin for 24 weeks improved cognitive performance, as assessed by the Wechsler Memory Scale–Revised, in depressed patients with T2DM. In addition, metformin significantly improved depressive performance and changed the glucose metabolism in depressed patients with diabetes. Depressive symptoms were negatively correlated with cognitive performance in metformin‐treated participants. Furthermore, associations were observed between the parameters of blood glucose metabolism and the depression phenotype. These findings suggest that chronic treatment with metformin has antidepressant behavioural effects and that improved cognitive function is involved in the therapeutic outcome of metformin. The results of the present study also raise the possibility that supplementary administration of antidiabetic medications may enhance the recovery of depression, comorbid with T2DM, through improvements in cognitive performance.
Assessment of autonomic functions in children with familial Mediterranean fever by using heart rate variability measurements
Authors: Fidanci Kursat , Gulgun Mustafa , Demirkaya Erkan , Acikel Cengizhan , Kilic Ayhan , Gok Faysal , Ozen Seza
Published: May 2014

Aim

The aim of this study is to analyze possible autonomic nerve system alterations and assess the efficacy of heart rate variability (HRV) analysis in anticipation of cardiovascular risks in pediatric patients with familial Mediterranean fever (FMF).

Method

In this study, cardiac autonomic functions were investigated in children with FMF by analyzing HRV and its other probable cardiac effects by echocardiography. We studied 70 pediatric patients with FMF and 50 healthy controls.

Results

The time‐domain parameters of HRV were compared between the FMF and control groups. SDNN (standard deviation of all NN intervals) was significantly decreased in patients with FMF as compared to control subjects. The other time‐domain parameters of HRV and the frequency‐domain parameters of HRV were similar in both groups. Frequency‐dependent HRV parameters were similar in both groups, as were conventional echocardiographic parameters.

Conclusion

HRV is a convenient and reliable technique for evaluation of autonomic functions. There are only a few studies on the assessment of autonomic functions by means of HRV in adult FMF patients but not in pediatric patients. Further studies are required to assess whether there is autonomic dysfunction in children with FMF.
TLR2 activation causes tachyphylaxis to β2‐agonists in vitro and ex vivo: modelling bacterial exacerbation
Authors: Alkhouri H. , Rumzhum N. N. , Rahman M. M. , FitzPatrick M. , de Pedro M. , Oliver B. G. , Bourke J. E. , Ammit A. J.
Published: May 2014

Background

Asthma is a widespread chronic health problem exacerbated by common viral and bacterial infections. Further research is required to understand how infection worsens asthma control in order to advance therapeutic options in the future. Recent research has revealed that β2‐adrenergic receptor (β2‐AR) agonists lose bronchodilatory efficacy because the receptor‐mediated molecular pathways responsible for their beneficial actions are desensitized by infection. To date, most studies have focussed on viral infection, leaving the impact of bacterial infection on β2‐AR desensitization relatively under‐investigated. We address this in this study.

Methods and Results

Utilizing an in vitro model of bacterial exacerbation in airway smooth muscle (ASM) cells, we show that activation of toll‐like receptor 2 (TLR2; mimicking bacterial infection) in the presence of an inflammatory stimulus leads to β2‐AR desensitization. This occurs via TLR2‐dependent upregulation of cyclooxygenase 2 (COX‐2) mRNA expression and increased secretion of PGE2. Importantly, PGE2 causes heterologous β2‐AR desensitization and reduces cAMP production in response to short‐acting (salbutamol) and long‐acting (formoterol) β2‐agonists. Thus, bacterial infectious stimuli act in a PGE2‐dependent manner to severely curtail the beneficial actions of β2‐agonists. The impact of β2‐AR desensitization is demonstrated by reduced gene expression of the critical anti‐inflammatory molecule MKP‐1 in response to β2‐agonists, as well as impaired bronchodilation in a mouse lung slices.

Conclusions

Taken together, our results show that, like viruses, bacteria induce prostanoid‐dependent β2‐AR desensitization on ASM cells. Notably, COX‐2 inhibition with the specific inhibitor celecoxib represses PGE2 secretion, presenting a feasible pharmacological option for treatment of infectious exacerbation in asthma in the future.
A comparison of total intravenous anaesthesia using propofol with sevoflurane or desflurane in ambulatory surgery: systematic review and meta‐analysis
Authors: Kumar G. , Stendall C. , Mistry R. , Gurusamy K. , Walker D.
Published: May 2014

With the popularity of ambulatory surgery ever increasing, we carried out a systematic review and meta‐analysis to determine whether the type of anaesthesia used had any bearing on patient outcomes. Total intravenous propofol anaesthesia was compared with two of the newer inhalational agents, sevoflurane and desflurane. In total, 18 trials were identified; only trials where nitrous oxide was administered to, or omitted from, both groups were included. A total of 1621 patients were randomly assigned to either propofol (685 patients) or inhalational anaesthesia (936 patients). If surgical causes of unplanned admissions were excluded, there was no difference in unplanned admission to hospital between propofol and inhalational anaesthesia (1.0% vs 2.9%, respectively; p = 0.13). The incidence of postoperative nausea and vomiting was lower with propofol than with inhalational agents (13.8% vs 29.2%, respectively; p < 0.001). However, no difference was noted in post‐discharge nausea and vomiting (23.9% vs 20.8%, respectively; p = 0.26). Length of hospital stay was shorter with propofol, but the difference was only 14 min on average. The use of propofol was also more expensive, with a mean (95% CI) difference of £6.72 (£5.13–£8.31 (€8.16 (€6.23−€10.09); $11.29 ($8.62–$13.96))) per patient‐anaesthetic episode (p < 0.001). Therefore, based on the published evidence to date, maintenance of anaesthesia using propofol appeared to have no bearing on the incidence of unplanned admission to hospital and was more expensive, but was associated with a decreased incidence of early postoperative nausea and vomiting compared with sevoflurane or desflurane in patients undergoing ambulatory surgery.
Functional bowel disorders in pregnancy: effect on quality of life, evaluation and management
Authors: Johnson Payton , Mount Kristy , Graziano Scott
Published: May 2014

Objective

To characterize functional bowel disorders in a population of pregnant women, evaluating effects on quality of life, management and follow up.

Design

Prospective cohort.

Setting

University center, USA.

Population

Women in the first trimester (n = 104).

Methods

After enrollment evaluations, measures were repeated in the third trimester. Overall bowel function was assessed using the Rome III Questionnaire for Functional Bowel Disorders. Quality of life symptoms were assessed with the Irritable Bowel Syndrome Quality of Life Measure. Physician documentation of bowel symptoms and subsequent treatment in pregnancy were ascertained by retrospective chart review.

Main outcome measure

Quality of life in first trimester.

Results

A majority (75%) of the women at the first trimester evaluation reported having one or more functional bowel disorders. The overall quality of life status was rated highly functional, with a total average score of 94.9. Of the 75 women reporting functional bowel disorders, only 18 (24%) were identified in the medical record. Overall documentation of any bowel function was identified in the majority (64%) of cases. Most commonly, no discussion of treatment was documented, and follow up was recorded in only 27% of women with dysfunction.

Conclusions

Nearly three‐quarters of women in the first trimester report symptoms consistent with functional bowel disorders. Overall quality of life measures are highly rated. There is a discrepancy between what women report regarding bowel dysfunction and what is documented by providers within the medical record.
Recurrence risk of low Apgar score among term singletons: a population‐based cohort study
Authors: Ensing Sabine , Schaaf Jelle M. , Abu‐Hanna Ameen , Mol Ben W.J. , Ravelli Anita C.J.
Published: May 2014

Objective

To examine the risk of recurrence of low Apgar score in a subsequent term singleton pregnancy.

Design

Population‐based cohort study.

Setting

The Netherlands.

Population

A total of 190 725 women with two subsequent singleton term live births between 1999 and 2007.

Methods

We calculated the recurrence risk of low Apgar score after adjustment for possible confounders. Women with an elective cesarean delivery, fetus in breech presentation or a fetus with congenital anomalies were excluded. Results were reported separately for women with a vaginal delivery or a cesarean delivery at first pregnancy.

Main outcome measures

Prevalence of birth asphyxia, a 5‐min Apgar score <7.

Results

The risk for an Apgar score of <7 in the first pregnancy was 0.99% and overall halved in the subsequent pregnancies (0.50%). For those with asphyxia in the first pregnancy, the risk of recurrence of a low Apgar score in the subsequent pregnancy was 1.1% (odds ratio 2.1, 95% confidence interval 1.4–3.3). This recurrence risk was present in women with a previous vaginal delivery (odds ratio 2.1, 95% confidence interval 1.2–3.5) and in women with a previous cesarean delivery (odds ratio 3.8, 95% confidence interval 1.7–8.5). Among women with a small‐for‐gestational‐age infant in the subsequent pregnancy and a previous vaginal delivery, the recurrence risk was 4.8% (adjusted odds ratio 5.8, 95% confidence interval 2.0–16.5).

Conclusion

Women with birth asphyxia of the first born have twice the risk of renewed asphyxia at the next birth compared to women without birth asphyxia of the first born. This should be incorporated in the risk assessment of pregnant women.
Survey of hospital procedures for parapneumonic effusion in children highlights need for standardised management
Authors: Le Mée A , Mordacq C , Lagrée M , Deschildre A , Martinot A , Dubos F
Published: May 2014

Aim

This study sought to evaluate the initial management of children with parapneumonic effusion admitted to all French university hospitals.

Methods

A nationwide survey of all 35 university hospitals took place in 2011 to assess practices for children with parapneumonic effusion, using a hypothetical clinical vignette and a standardised questionnaire. Two to four paediatricians per hospital were interviewed and asked about their initial management, probabilistic antibiotic therapy and its adaptation to microbiological results and subsequent course. Answers from paediatricians working in emergency departments, intensive care units and conventional paediatric units were compared.

Results

Of the 100 paediatricians contacted, 95 responded. Of these, 98% would order an initial blood test, 70% would order diagnostic thoracentesis, and all would start immediate antibiotic therapy: 31% with a single drug, 67% with two drugs and 2% with three drugs. The most frequent initial choices were third‐generation cephalosporin alone (17%) or combined with rifampicin (34%) or vancomycin (24%). Adaptation varied according to drug used, dose and duration, especially when the microorganism was not Streptococcus pneumoniae. Practices did not differ significantly among the different groups of paediatricians.

Conclusion

Standardised management of parapneumonic effusion, including routine thoracentesis and more consistent prescription of antibiotics, is needed.
Transforming growth factor‐β‐induced lncRNA‐Smad7 inhibits apoptosis of mouse breast cancer JygMC(A) cells
Authors: Arase Mayu , Horiguchi Kana , Ehata Shogo , Morikawa Masato , Tsutsumi Shuichi , Aburatani Hiroyuki , Miyazono Kohei , Koinuma Daizo
Published: May 2014

Transforming growth factor (TGF)‐β exhibits both pro‐apoptotic and anti‐apoptotic effects on epithelial cells in a context‐dependent manner. The anti‐apoptotic function of TGF‐β is mediated by several downstream regulatory mechanisms, and has been implicated in the tumor‐progressive phenotype of breast cancer cells. We conducted RNA sequencing of mouse mammary gland epithelial (NMuMG) cells and identified a long non‐coding RNA, termed lncRNA‐Smad7, which has anti‐apoptotic functions, as a target of TGF‐β. lncRNA‐Smad7 was located adjacent to the mouse Smad7 gene, and its expression was induced by TGF‐β in all of the mouse mammary gland epithelial cell lines and breast cancer cell lines that we evaluated. Suppression of lncRNA‐Smad7 expression cancelled the anti‐apoptotic function of TGF‐β. In contrast, forced expression of lncRNA‐Smad7 rescued apoptosis induced by a TGF‐β type I receptor kinase inhibitor in the mouse breast cancer cell line JygMC(A). The anti‐apoptotic effect of lncRNA‐Smad7 appeared to occur independently of the transcriptional regulation by TGF‐β of anti‐apoptotic DEC1 and pro‐apoptotic Bim proteins. Small interfering RNA for lncRNA‐Smad7 did not alter the process of TGF‐β‐induced epithelial–mesenchymal transition, phosphorylation of Smad2 or expression of the Smad7 gene, suggesting that the contribution of this lncRNA to TGF‐β functions may be restricted to apoptosis. Our findings suggest a complex mechanism for regulating the anti‐apoptotic and tumor‐progressive aspects of TGF‐β signaling.
In vivo imaging of membrane type‐1 matrix metalloproteinase with a novel activatable near‐infrared fluorescence probe
Authors: Shimizu Yoichi , Temma Takashi , Hara Isao , Makino Akira , Kondo Naoya , Ozeki Ei‐ichi , Ono Masahiro , Saji Hideo
Published: May 2014

Membrane type‐1 matrix metalloproteinase (MT1‐MMP) is a protease activating MMP‐2 that mediates cleavage of extracellular matrix components and plays pivotal roles in tumor migration, invasion and metastasis. Because in vivo noninvasive imaging of MT1‐MMP would be useful for tumor diagnosis, we developed a novel near‐infrared (NIR) fluorescence probe that can be activated following interaction with MT1‐MMP in vivo. MT1‐hIC7L is an activatable fluorescence probe comprised of anti‐MT1‐MMP monoclonal antibodies conjugated to self‐assembling polymer micelles that encapsulate NIR dyes (IC7‐1, λem: 858 nm) at concentrations sufficient to cause fluorescence self‐quenching. In aqueous buffer, MT1‐hIC7L fluorescence was suppressed to background levels and increased approximately 35.5‐fold in the presence of detergent. Cellular uptake experiments revealed that in MT1‐MMP positive C6 glioma cells, MT1‐hIC7L showed significantly higher fluorescence that increased with time as compared to hIC7L, a negative control probe lacking the anti‐MT1‐MMP monoclonal antibody. In MT1‐MMP negative MCF‐7 breast adenocarcinoma cells, both MT1‐hIC7L and hIC7L showed no obvious fluorescence. In addition, the fluorescence intensity of C6 cells treated with MT1‐hIC7L was suppressed by pre‐treatment with an MT1‐MMP endocytosis inhibitor (P < 0.05). In vivo optical imaging using probes intravenously administered to tumor‐bearing mice showed that MT1‐hIC7L specifically visualized C6 tumors (tumor‐to‐background ratios: 3.8 ± 0.3 [MT1‐hIC7L] vs 3.1 ± 0.2 [hIC7L] 48 h after administration, P < 0.05), while the probes showed similarly low fluorescence in MCF‐7 tumors. Together, these results show that MT1‐hIC7L would be a potential activatable NIR probe for specifically detecting MT1‐MMP‐expressing tumors.
Control over a stressor involves the posterior dorsal striatum and the act/outcome circuit
Authors: Amat Jose , Christianson John P. , Aleksejev Roman M. , Kim Janet , Richeson Kaitlin R. , Watkins Linda R. , Maier Steven F.
Published: May 2014

Controllable/escapable tailshocks (ESs) do not produce the behavioral and neurochemical outcomes produced by equal yoked uncontrollable/inescapable tailshocks (ISs). The prelimbic cortex is known to play a key role in mediating the protective effects of control. The concepts of act/outcome learning and control seem similar, and act/outcome learning is mediated by a circuit involving the prelimbic cortex and posterior dorsomedial striatum (DMS). Thus, we tested the involvement of the DMS in the protective effect of ES, in rats. First, we examined Fos immunoreactivity in both the DMS and dorsolateral striatum (DLS) after ES and yoked IS. We then investigated the effect of blocking DMS or DLS N‐methyl‐d‐aspartate receptors with the specific antagonist D‐(‐)‐2‐amino‐5‐phosphopentanoic acid (D‐AP5) on the release of dorsal raphe nucleus serotonin (5‐HT) during ES, as well as on the level of anxiety produced by the ES experience 24 h later. ES, but not yoked IS, produced a large increase of Fos activity in the DMS. Consistent with the Fos data, D‐AP5 in the DMS, but not in the DLS, prevented the inhibition of dorsal raphe nucleus 5‐HT release normally produced by ES. Furthermore, D‐AP5 administered into the DMS before ES, but not into the DLS, increased anxiety 24 h later, leading to levels similar to those produced by IS. These results suggest that, as with appetitive act/outcome contingency learning, the protective effects of behavioral control over a stressor require the DMS.
Oral administration of Polypodium leucotomos delays skin tumor development and increases epidermal p53 expression and the anti‐oxidant status of UV‐irradiated hairless mice
Authors: Rodríguez‐Yanes Esperanza , Cuevas Jesús , González Salvador , Mallol Jordi
Published: May 2014

Chronic exposure to ultraviolet radiation (UVR) induces skin tumors in hairless mice. Daily oral administration of a Polypodium leucotomos (PL) extract significantly delayed tumor development in PL‐treated versus non‐PL‐treated mice. UVR and/or PL treatment modified several oxidative stress markers. In all irradiated mice, erythrocytic glutathione S‐transferase (GST) activity and glutathione disulphide (GSSG) content increased and in all PL‐treated mice GSSG content decreased, specially in non‐irradiated animals, and total plasma anti‐oxidant capacity (ORAC) increased. In dorsolateral non‐tumoral skin of all irradiated mice, glutathione reductase (GR) and glutathione peroxidase (GPx) activities increased and GSSG decreased in non‐irradiated PL‐treated animals. UVR induced a steep increase of p53 expression in epidermal cells. In non‐tumoral skin, this increase was significantly higher in PL‐treated animals than in non‐treated mice and can contribute in delaying tumor development, either by repairing the damaged DNA or by increasing apoptosis. These results reinforce the usefulness of PL as systemic photoprotective agent, especially in patients highly sensitive to UVR.
Bullous pemphigoid induced by vildagliptin: a report of three cases
Authors: Béné Johana , Jacobsoone Aurélie , Coupe Patrick , Auffret Marine , Babai Samy , Hillaire‐Buys Dominique , Jean‐Pastor Marie‐Josèphe , Vonarx Marlène , Vermersch Annie , Tronquoy Anne‐Fleur , Gautier Sophie
Published: May 2014

To report three cases of bullous pemphigoid in patients treated with vildagliptin. Case 1: An 86‐year‐old woman presented with bullous pemphigoid after 1 month of treatment with vildagliptin and metformin. After introduction of clobetasol, the symptoms resolved although vildagliptin was continued. However, the skin lesions reappeared 3 months later. Sustained remission was achieved only after definitive withdrawal of vildagliptin. Case 2: A 79‐year‐old man presented with bullous pemphigoid after 37‐month treatment with gliclazide, vildagliptin and metformin. The disease at first responded to clobetasol but 3 months later the lesions reappeared. They finally regressed when the gliptin was discontinued. Case 3: A 77‐year‐old woman, treated with gliclazide and vildagliptin for 26 months, presented with bullous pemphigoid, which responded well to discontinuation of the gliptin and topical clobetasol. Gliptins are new molecules for treatment of type 2 diabetes mellitus, which have been suspected of implication in bullous pemphigoid. Such cases have been described in the literature (seven with vildagliptin and three with sitagliptin). In nine of these cases, the gliptin was associated with metformin, but the latter had never been considered responsible. The mechanism implicated in the development of bullous pemphigoid has not yet been clearly identified, but may involve a modified immune response or alteration of the antigenic properties of the epidermal basement membrane. These reports support the risk of bullous pemphigoid in patients exposed to gliptins.