Structure determination from powder data : Mogul and CASTEP

When solving the crystal structure of complex molecules from powder data, accurately locating the global minimum can be challenging, particularly where the number of internal degrees of freedom is large. The program Mogul provides a convenient means to access typical torsion angle ranges for fragments related to the molecule of interest. The impact that the application of modal torsion angle constraints has on the structure determination process of two structure solution attempts using DASH is presented. Once solved, accurate refinement of a molecular structure against powder data can also present challenges. Geometry optimisation using density functional theory in CASTEP is shown to be an effective means to locate hydrogen atom positions reliably and return a more accurate description of molecular conformation and intermolecular interactions than global optimisation and Rietveld refinement alone

3-Amino­carbonyl­pyridinium difluoro­acetate at 123 K

In the crystal of the title compound, C6H7N2O+·C2HF2O2 −, the cation adopts a catemeric N—H⋯O hydrogen-bonded chain motif involving the carboxamide group, with two further N—H⋯O hydrogen bonds connecting the cations to adjacent difluoro­acetate anions via the carboxamide and pyridinium N atoms. The carboxamide group of the nicotinamidium ion is twisted by 32.3 (6)° from the pyridine ring plane. A number of C—H⋯O and C—H⋯F interactions consolidate the packing

Nicotinamide–2,2,2-trifluoro­ethanol (2/1)

The nicotinamide (NA) mol­ecules of the title compound, 2C6H6N2O·C2H3F3O, form centrosymmetric R 2 2(8) hydrogen-bonded dimers via N—H⋯O contacts. The asymmetric unit contains two mol­ecules of NA and one trifluoroethanol molecule disordered over two sites of equal occupancy. The packing consists of alternating layers of nicotinamide dimers and disordered 2,2,2-trifluoro­ethanol mol­ecules stacking in the c-axis direction. Intra­molecular C—H⋯O and inter­molecular N—H⋯N, O—H⋯N, C—H⋯N, C—H⋯O and C—H⋯F inter­actions are present

Emerging microRNA Therapeutic Approaches for Cystic Fibrosis

Cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene and remains the most common life-shortening diseases affecting the exocrine organs. The absence of this channel results in an imbalance of ion concentrations across the cell membrane and results in more abnormal secretion and mucus plugging in the gastrointestinal tract and in the lungs of CF patients. The direct introduction of fully functional CFTR by gene therapy has long been pursued as a therapeutical option to restore CFTR function independent of the specific CFTR mutation, but the different clinical trials failed to propose persuasive evidence of this strategy. The last ten years has led to the development of new pharmacotherapies which can activate CFTR function in a mutation-specific manner. Although approximately 2,000 different disease-associated mutations have been identified, a single codon deletion, F508del, is by far the most common and is present on at least one allele in approximately 70% of the patients in CF populations. This strategy is limited by chemistry, the knowledge on CFTR and the heterogenicity of the patients. New research efforts in CF aim to develop other therapeutical approaches to combine different strategies. Targeting RNA appears as a new and an important opportunity to modulate dysregulated biological processes. Abnormal miRNA activity has been linked to numerous diseases, and over the last decade, the critical role of miRNA in regulating biological processes has fostered interest in how miRNA binds to and interacts explicitly with the target protein. Herein, this review describes the different strategies to identify dysregulated miRNA opens up a new concept and new opportunities to correct CFTR deficiency. This review describes therapeutic applications of antisense techniques currently under investigation in CF

Structure and stability of two polymorphs of creatine and its monohydrate

An experimental search for crystalline forms of creatine including a variable temperature X-ray powder diffraction study has produced three polymorphs and a formic acid solvate. The crystal structures of creatine forms I and II were determined from X-ray powder diffraction data plus the creatine formic acid (1 : 1) solvate structure was obtained by single crystal X-ray diffraction methods. Evidence of a third polymorphic form of creatine obtained by rapid desolvation of creatine monohydrate is also presented. The results highlight the role of automated parallel crystallisation, slurry experiments and VT-XRPD as powerful techniques for effective physical form screening. They also highlight the importance of various complementary analytical techniques in structural characterisation and in achieving better understanding of the relationship between various solid-state forms. The structural relationships between various solid-state forms of creatine using the XPac method provided a rationale for the different relative stabilities of forms I and II of creatine with respect to the monohydrate form

Ptk7-Deficient Mice Have Decreased Hematopoietic Stem Cell Pools as a Result of Deregulated Proliferation and Migration

International audienceHematopoietic stem cells (HSCs) located in adult bone marrow or fetal liver in mammals produce all cells from the blood system. Atthe top of the hierarchy are long-term HSCs endowed with lifelong self-renewal and differentiation properties. These features arecontrolled through key microenvironmental cues and regulatory pathways, such as Wnt signaling.We showed previously that PTK7,a tyrosine kinase receptor involved in planar cell polarity, plays a role in epithelial Wnt signaling; however, its function in hematopoiesishas remained unexplored. In this article, we show that PTK7 is expressed by hematopoietic stem and progenitor cells, withthe highest level of protein expression found on HSCs. Taking advantage of a Ptk7-deficient mouse strain, we demonstrate that loss ofPtk7 leads to a diminished pool of HSCs but does not affect in vitro or in vivo hematopoietic cell differentiation. This is correlatedwith increased quiescence and reduced homing abilities of Ptk7-deficient hematopoietic stem and progenitor cells, unraveling noveland unexpected functions for planar cell polarity pathways in HSC fate

A multicentre, randomised, double-blind, placebo-controlled trial with the interleukin-1 receptor antagonist anakinra in patients with systemic-onset juvenile idiopathic arthritis (ANAJIS trial)

To assess the efficacy of the interleukin 1 receptor antagonist anakinra in systemic-onset juvenile idiopathic arthritis (SJIA).status: publishe

Increased serum levels of fractalkine and mobilisation of CD34+CD45− endothelial progenitor cells in systemic sclerosis

International audienceBackground: The disruption of endothelial homeostasis is a major determinant in the pathogenesis of systemic sclerosis (SSc) and is reflected by soluble and cellular markers of activation, injury and repair. We aimed to provide a combined assessment of endothelial markers to delineate specific profiles associated with SSc disease and its severity

Gout and pseudo-gout-related crystals promote GLUT1-mediated glycolysis that governs NLRP3 and interleukin-1β activation on macrophages

Objective Macrophage activation by monosodium urate (MSU) and calcium pyrophosphate (CPP) crystals mediates an interleukin (IL)-1β-dependent inflammation during gout and pseudo-gout flare, respectively. Since metabolic reprogramming of macrophages goes along with inflammatory responses dependently on stimuli and tissue environment, we aimed to decipher the role of glycolysis and oxidative phosphorylation in the IL-1β-induced microcrystal response. Methods Briefly, an in vitro study (metabolomics and real-time extracellular flux analysis) on MSU and CPP crystal-stimulated macrophages was performed to demonstrate the metabolic phenotype of macrophages. Then, the role of aerobic glycolysis in IL-1β production was evaluated, as well in vitro as in vivo using 18F-fluorodeoxyglucose positron emission tomography imaging and glucose uptake assay, and molecular approach of glucose transporter 1 (GLUT1) inhibition. Results We observed that MSU and CPP crystals led to a metabolic rewiring toward the aerobic glycolysis pathway explained by an increase in GLUT1 plasma membrane expression and glucose uptake on macrophages. Also, neutrophils isolated from human synovial fluid during gout flare expressed GLUT1 at their plasma membrane more frequently than neutrophils isolated from bloodstream. Both glucose deprivation and treatment with either 2-deoxyglucose or GLUT1 inhibitor suppressed crystal-induced NLRP3 activation and IL-1β production, and microcrystal inflammation in vivo. Conclusion In conclusion, we demonstrated that GLUT1-mediated glucose uptake is instrumental during the inflammatory IL-1β response induced by MSU and CPP crystals. These findings open new therapeutic paths to modulate crystal-related inflammation

Mucoviscidose : dans la ligne des miR

La mucoviscidose est la plus fréquente des maladies génétiques dans les populations d’origine caucasienne, caractérisée par des mutations du gène codant le canal chlorure CFTR. Bien que ce gène soit connu depuis 1989, les solutions thérapeutiques curatives proposées aux patients restent limitées. De nouvelles stratégies thérapeutiques sont explorées, comme celles ciblant les microARN qui participent à la régulation de l’expression d’ARN messagers cibles. Cette revue fait le point sur les travaux portant sur l’implication de ces microARN dans la mucoviscidose, notamment dans le contrôle des canaux ioniques, de l’inflammation, de l’infection et de l’obstruction bronchique, et leurs potentiels thérapeutiques