Molecular structure and semiexternal molecular motions in 2,4,5-trichlorobenzenesulfonyl chloride, C6H2Cl4O2S

The molecular structure of 2,4,5-trichlorobenzenesulfonyl chloride has been determined by X-ray diffraction methods. The compound is orthorhombic,Aba2, witha=16.253(12),b=17.016(9),c=7.146(5) A,V=1976(5) A3,Z=8,D=1.88 kg·mm−3, (MoKα)=0.7107 A,μ=136.8 cm−1,F(000)=1104. Data were obtained at room temperature; the finalR is 0.029 for 854 independent reflections. The substituted benzene ring is planar within experimental accuracy, the dihedral angle with the C(1)-S(1)-Cl(1) plane being 66.0(5)°. The compound has normal bond lengths and angles; some short intramolecular distances account for the maintenance of the rigid benzene frame. No significatively short intermolecular distances have been found. Confirmation of the oscillatory character of the semiexternal molecular motions operating above 180 K is accounted for.Facultad de Ciencias Exacta

Systematic Computational and Experimental Investigation of Lithium-Ion Transport Mechanisms in Polyester-Based Polymer Electrolytes

Understanding the mechanisms of lithium-ion transport in polymers is crucial for the design of polymer electrolytes. We combine modular synthesis, electrochemical characterization, and molecular simulation to investigate lithium-ion transport in a new family of polyester-based polymers and in poly(ethylene oxide) (PEO). Theoretical predictions of glass-transition temperatures and ionic conductivities in the polymers agree well with experimental measurements. Interestingly, both the experiments and simulations indicate that the ionic conductivity of PEO, relative to the polyesters, is far higher than would be expected from its relative glass-transition temperature. The simulations reveal that diffusion of the lithium cations in the polyesters proceeds via a different mechanism than in PEO, and analysis of the distribution of available cation solvation sites in the various polymers provides a novel and intuitive way to explain the experimentally observed ionic conductivities. This work provides a platform for the evaluation and prediction of ionic conductivities in polymer electrolyte materials

Nano-Stenciled RGD-Gold Patterns That Inhibit Focal Contact Maturation Induce Lamellipodia Formation in Fibroblasts

Cultured fibroblasts adhere to extracellular substrates by means of cell-matrix adhesions that are assembled in a hierarchical way, thereby gaining in protein complexity and size. Here we asked how restricting the size of cell-matrix adhesions affects cell morphology and behavior. Using a nanostencil technique, culture substrates were patterned with gold squares of a width and spacing between 250 nm and 2 µm. The gold was functionalized with RGD peptide as ligand for cellular integrins, and mouse embryo fibroblasts were plated. Limiting the length of cell-matrix adhesions to 500 nm or less disturbed the maturation of vinculin-positive focal complexes into focal contacts and fibrillar adhesions, as indicated by poor recruitment of α5-integrin. We found that on sub-micrometer patterns, fibroblasts spread extensively, but did not polarize. Instead, they formed excessive numbers of lamellipodia and a fine actin meshwork without stress fibers. Moreover, these cells showed aberrant fibronectin fibrillogenesis, and their speed of directed migration was reduced significantly compared to fibroblasts on 2 µm square patterns. Interference with RhoA/ROCK signaling eliminated the pattern-dependent differences in cell morphology. Our results indicate that manipulating the maturation of cell-matrix adhesions by nanopatterned surfaces allows to influence morphology, actin dynamics, migration and ECM assembly of adhering fibroblasts

Integrin-Specific Mechanoresponses to Compression and Extension Probed by Cylindrical Flat-Ended AFM Tips in Lung Cells

Cells from lung and other tissues are subjected to forces of opposing directions that are largely transmitted through integrin-mediated adhesions. How cells respond to force bidirectionality remains ill defined. To address this question, we nanofabricated flat-ended cylindrical Atomic Force Microscopy (AFM) tips with ∼1 µm2 cross-section area. Tips were uncoated or coated with either integrin-specific (RGD) or non-specific (RGE/BSA) molecules, brought into contact with lung epithelial cells or fibroblasts for 30 s to form focal adhesion precursors, and used to probe cell resistance to deformation in compression and extension. We found that cell resistance to compression was globally higher than to extension regardless of the tip coating. In contrast, both tip-cell adhesion strength and resistance to compression and extension were the highest when probed at integrin-specific adhesions. These integrin-specific mechanoresponses required an intact actin cytoskeleton, and were dependent on tyrosine phosphatases and Ca2+ signaling. Cell asymmetric mechanoresponse to compression and extension remained after 5 minutes of tip-cell adhesion, revealing that asymmetric resistance to force directionality is an intrinsic property of lung cells, as in most soft tissues. Our findings provide new insights on how lung cells probe the mechanochemical properties of the microenvironment, an important process for migration, repair and tissue homeostasis

Paxillin and Hic-5 Interaction with Vinculin Is Differentially Regulated by Rac1 and RhoA

Cell migration is of paramount importance to organism development and maintenance as well as multiple pathological processes, including cancer metastasis. The RhoGTPases Rac1 and RhoA are indispensable for cell migration as they regulate cell protrusion, cell-extracellular matrix (ECM) interactions and force transduction. However, the consequences of their activity at a molecular level within the cell remain undetermined. Using a combination of FRET, FRAP and biochemical analyses we show that the interactions between the focal adhesion proteins vinculin and paxillin, as well as the closely related family member Hic-5 are spatially and reciprocally regulated by the activity of Rac1 and RhoA. Vinculin in its active conformation interacts with either paxillin or Hic-5 in adhesions in response to Rac1 and RhoA activation respectively, while inactive vinculin interacts with paxillin in the membrane following Rac1 inhibition. Additionally, Rac1 specifically regulates the dynamics of paxillin as well as its binding partner and F-actin interacting protein actopaxin (α-parvin) in adhesions. Furthermore, FRET analysis of protein:protein interactions within cell adhesions formed in 3D matrices revealed that, in contrast to 2D systems vinculin interacts preferentially with Hic-5. This study provides new insight into the complexity of cell-ECM adhesions in both 2D and 3D matrices by providing the first description of RhoGTPase-coordinated protein:protein interactions in a cellular microenvironment. These data identify discrete roles for paxillin and Hic-5 in Rac1 and RhoA-dependent cell adhesion formation and maturation; processes essential for productive cell migration

De novo variants in the RNU4-2 snRNA cause a frequent neurodevelopmental syndrome.

Around 60% of individuals with neurodevelopmental disorders (NDD) remain undiagnosed after comprehensive genetic testing, primarily of protein-coding genes1. Large genome-sequenced cohorts are improving our ability to discover new diagnoses in the non-coding genome. Here we identify the non-coding RNA RNU4-2 as a syndromic NDD gene. RNU4-2 encodes the U4 small nuclear RNA (snRNA), which is a critical component of the U4/U6.U5 tri-snRNP complex of the major spliceosome2. We identify an 18 base pair region of RNU4-2 mapping to two structural elements in the U4/U6 snRNA duplex (the T-loop and stem III) that is severely depleted of variation in the general population, but in which we identify heterozygous variants in 115 individuals with NDD. Most individuals (77.4%) have the same highly recurrent single base insertion (n.64_65insT). In 54 individuals in whom it could be determined, the de novo variants were all on the maternal allele. We demonstrate that RNU4-2 is highly expressed in the developing human brain, in contrast to RNU4-1 and other U4 homologues. Using RNA sequencing, we show how 5 splice-site use is systematically disrupted in individuals with RNU4-2 variants, consistent with the known role of this region during spliceosome activation. Finally, we estimate that variants in this 18 base pair region explain 0.4% of individuals with NDD. This work underscores the importance of non-coding genes in rare disorders and will provide a diagnosis to thousands of individuals with NDD worldwide

Sincronização da onda folicular com buserelina prévia à indução da luteólise com cloprostenol em bovinos

Este experimento foi realizado para verificar o efeito da aplicação de diferentes doses de um análogo de GnRH (buserelina) sobre a emergência de nova onda de crescimento folicular e o número de folículos recrutados dessa onda, a formação de corpo lúteo acessório, o diâmetro do folículo dominante e do corpo lúteo espontâneo no dia da aplicação do luteolítico e subseqüente taxa de sincronização e o intervalo da aplicação de PGF2α à manifestação do estro. Vinte fêmeas bovinas em diestro, mestiças Holandês x Zebu e Simental x Zebu foram, distribuídas em quatro tratamentos contendo cinco animais cada. No tratamento 1, os animais receberam 4 mg IM de buserelina no dia z 0 (dia em que se iniciou o tratamento) e 150 mg de D(+) cloprostenol no dia 6. Nos tratamentos 2, 3 e 4, receberam, respectivamente, 6, 8 e 10 mg de buserelina, pela mesma via de aplicação, e 150mg de D(+) cloprostenol no dia 6. A atividade ovariana foi monitorada diariamente, com auxílio do aparelho de ultra-sonografia, do dia 0 ao estro, ou até o dia 11 pós-tratamento, naqueles animais que não responderam à prostaglandina. A aplicação de 8 ou 10 mg de buserelina em fase indeterminada do diestro, nas fêmeas bovinas mestiças, promoveu emergência de nova onda de crescimento folicular mais rápida que aplicações de 4 ou 6 mg do mesmo hormônio; enquanto os outros parâmetros avaliados não diferiram entre os animais dos tratamentos.This experiment was carried out to verify the effect of the administration of different doses of GnRH (buserelin) analogue on the emergence of a new follicular growth wave and the number of recruited follicles from this wave, accessory corpus luteum formation, the dominant follicle diameter and the spontaneous corpus luteum on the luteolitic administration day and subsequent synchronization rate and the interval between the PGF2α application and the estrus manifestation. Twenty crossbreed female cattle in diestrus, crossbred Holstein x Zebu and Simental x Zebu were allotted to four treatment groups, each containing five animals. In the treatment 1 the animals received 4 mg IM. of buserelin at day 0 (day in which the treatment began) and 150 mg of D (+) Cloprostenol at day 6. In treatments 2, 3 and 4, the animals received 6, 8 and 10 mg of buserelin, respectively, by the same application way, and 150 mg of D (+) Cloprostenol at day 6. The ovarian activity was daily monitored, with the help of an ultra-sound machine, from day 0 to estrus or until day 11 on those animals, which did not answer to prostaglandin. The application of 8 or 10 mg of buserelin at an unknown phase of diestrus, in female crossbred cattle, promoted an emergence of a new follicular growth wave faster than the applications of 4 or 6 mg of the same hormones, while the other evaluated parameters did not differ among treatments

Quantitative trait loci identified for blood chemistry components of an advanced intercross line of chickens under heat stress

Background: Heat stress in poultry results in considerable economic losses and is a concern for both animal health and welfare. Physiological changes occur during periods of heat stress, including changes in blood chemistry components. A highly advanced intercross line, created from a broiler (heat susceptible) by Fayoumi (heat resistant) cross, was exposed to daily heat cycles for seven days starting at 22 days of age. Blood components measured pre-heat treatment and on the seventh day of heat treatment included pH, pCO2, pO2, base excess, HCO3, TCO2, K, Na, ionized Ca, hematocrit, hemoglobin, sO2, and glucose. A genome-wide association study (GWAS) for these traits and their calculated changes was conducted to identify quantitative trait loci (QTL) using a 600 K SNP panel. Results: There were significant increases in pH, base excess, HCO3, TCO2, ionized Ca, hematocrit, hemoglobin, and sO2, and significant decreases in pCO2 and glucose after 7 days of heat treatment. Heritabilities ranged from 0.01-0.21 for pre-heat measurements, 0.01-0.23 for measurements taken during heat, and 0.00-0.10 for the calculated change due to heat treatment. All blood components were highly correlated within measurement days, but not correlated between measurement days. The GWAS revealed 61 QTL for all traits, located on GGA (Gallus gallus chromosome) 1, 3, 6, 9, 10, 12–14, 17, 18, 21–28, and Z. A functional analysis of the genes in these QTL regions identified the Angiopoietin pathway as significant. The QTL that co-localized for three or more traits were on GGA10, 22, 26, 28, and Z and revealed candidate genes for birds’ response to heat stress. Conclusions: The results of this study contribute to our knowledge of levels and heritabilities of several blood components of chickens under thermoneutral and heat stress conditions. Most components responded to heat treatment. Mapped QTL may serve as markers for genomic selection to enhance heat tolerance in poultry. The Angiopoietin pathway is likely involved in the response to heat stress in chickens. Several candidate genes were identified, giving additional insight into potential mechanisms of physiologic response to high ambient temperatures