Alterations in cerebrospinal fluid uridine,hypoxanthine, and xanthine in head-injured patients

1. Examination of the cerebrospinal fluid (CSF) of head-injured patients reveals that the concentration of intraventricular xanthine is elevated and that of uridine is decreased relative to those of adult lumbar CSF. 2. No correlations were observed between CSF lactate and CSF hypoxanthine, xanthine, or uridine, suggesting that changes in purine metabolites and the pyrimidine nucleoside do not index similar cellular events as does lactic acid production. 3. Ventricular CSF from hydrocephalic infants had uridine and hypoxanthine concentrations not significantly different from those of normal adult lumbar CSF, but xanthine was significantly elevated. 4. Since uridine has anticonvulsant properties and is a crucial substrate for cerebral metabolism, it may be useful to evaluate this pyrimidine for use in the management of patients with head injury.     

PYK2 is overexpressed in chronic lymphocytic leukaemia: A potential new therapeutic target

Chronic Lymphocytic Leukaemia (CLL) is the most common adult B-cell leukaemia and despite improvement in patients' outcome, following the use of targeted therapies, it remains incurable. CLL supportive microenvironment plays a key role in both CLL progression and drug resistance through signals that can be sensed by the main components of the focal adhesion complex, such as FAK and PYK2 kinases. Dysregulations of both kinases have been observed in several metastatic cancers, but their role in haematological malignancies is still poorly defined. We characterized FAK and PYK2 expression and observed that PYK2 expression is higher in leukaemic B cells and its overexpression significantly correlates with their malignant transformation. When targeting both FAK and PYK2 with the specific inhibitor defactinib, we observed a dose–response effect on CLL cells viability and survival. In vivo treatment of a CLL mouse model showed a decrease of the leukaemic clone in all the lymphoid organs along with a significant reduction of macrophages and of the spleen weight and size. Our results first define a possible prognostic value for PYK2 in CLL, and show that both FAK and PYK2 might become putative targets for both CLL and its microenvironment (e.g. macrophages), thus paving the way to an innovative therapeutic strategy.     

Differential microRNA Profiles and Their Functional Implications in Different Immunogenetic Subsets of Chronic Lymphocytic Leukemia

Critical processes of B-cell physiology, including immune signaling through the B-cell receptor (BcR) and/or Toll-like receptors (TLRs), are targeted by microRNAs. With this in mind and also given the important role of BcR and TLR signaling and microRNAs in chronic lymphocytic leukemia (CLL), we investigated whether microRNAs could be implicated in shaping the behavior of CLL clones with distinct BcR and TLR molecular and functional profiles. To this end, we examined 79 CLL cases for the expression of 33 microRNAs, selected on the following criteria: (a) deregulated in CLL versus normal B-cells; (b) differentially expressed in CLL subgroups with distinct clinicobiological features; and, (c) if meeting (a) + (b), having predicted targets in the immune signaling pathways. Significant upregulation of miR-150, miR-29c, miR-143 and miR-223 and downregulation of miR-15a was found in mutated versus unmutated CLL, with miR-15a showing the highest fold difference. Comparison of two major subsets with distinct stereotyped BcRs and signaling signatures, namely subset 1 [IGHV1/5/7-IGKV1(D)-39, unmutated, bad prognosis] versus subset 4 [IGHV4-34/IGKV2-30, mutated, good prognosis] revealed differences in the expression of miR-150, miR-29b, miR-29c and miR-101, all down-regulated in subset 1. We were also able to link these distinct microRNA profiles with cellular phenotypes, importantly showing that, in subset 1, miR-101 downregulation is associated with overexpression of the enhancer of zeste homolog 2 (EZH2) protein, which has been associated with clinical aggressiveness in other B-cell lymphomas. In conclusion, specific miRNAs differentially expressed among CLL subgroups with distinct BcR and/or TLR signaling may modulate the biological and clinical behavior of the CLL clones.     

Crop plants with improved culture and quality traits for food,feed and other uses

The large French research project GENIUS (2012–2019, https://www6.inra.genius-project_eng/) provides a good showcase of current genome editing techniques applied to crop plants. It addresses a large variety of agricultural species (rice, wheat, maize, tomato, potato, oilseed rape, poplar, apple and rose) together with some models (Arabidopsis, Brachypodium, Physcomitrella). Using targeted mutagenesis as its work horse, the project is limited to proof of concept under confined conditions. It mainly covers traits linked to crop culture, such as disease resistance to viruses and fungi, flowering time, plant architecture, tolerance to salinity and plant reproduction but also addresses traits improving the quality of agricultural products for industrial purposes. Examples include virus resistant tomato, early flowering apple and low-amylose starch potato. The wide range of traits illustrates the potential of genome editing towards a more sustainable agriculture through the reduction of pesticides and to the emergence of innovative bio-economy sectors based on custom tailored quality traits.

     

A role for chromogranin A (4-16), a vasostatin-derived peptide, on human colonic motility. An in vitro study

The hypothesis that CgA-derived peptides may be involved in mechanisms modulating motility was tested. Human colonic smooth muscles were studied using an organ bath technique. Acetic acid (AA) effects were characterized on spontaneous mechanical activities (SMA) and on responses to transmural nerve stimulation (NS). AA induced a significant decrease in tone and abolished SMA; this effect was insensitive to either TTX or L-NAME/apamin. The AA-induced inhibitory effects were significantly reduced in the presence of CgA4-16. This effect was insensitive to TTX or L-NAME/apamin. Furthermore, AA-induced effects were blocked in the presence of BAYK8644 and CgA4-16 together. The inhibitory effect of nifedipine was delayed in the presence of CgA4-16. NS induced a triphasic response. Only the excitatory components were reduced in the presence of AA. This effect was dose-related and remained unchanged in the presence of CgA4-16 alone, but was blocked in the presence of simultaneous administration of CgA4-16 and L-NAME/apamin. AA application induced inhibition of human colon motility in vitro. This effect may be mediated through an action on L-type calcium channels. CgA4-16 may display a protective role, which prevents the inhibition of motility due to AA to occur, by acting on both smooth muscle and afferent terminals.     

Effects of a chromogranin-derived peptide (CgA 47-66) in the writhing nociceptive response induced by acetic acid in rats

Chromogranin A (CgA) is an acidic protein identified within a large variety of endocrine cells. Colocalized with catecholamines in chromaffin cells, CgA is a prohormone precursor of small biologically active peptides. Vasostatin (CgA 1-76) is the most conserved fragment of CgA and chromogranin A 47-66 peptide (CgA 47-66) possesses potent antimicrobial activities. The aim of this study was to test the hypothesis that CgA 47-66 may be involved in mechanisms modulating nociception. Thus, we used acetic acid (AA) which produces a delayed inflammatory response and episodes of abdominal writhing, a marker of pain, when injected intraperitoneally (i.p.) to rats. Administration (i.p.) of CgA 47-66 induced specific opposite dose-dependent effects depending on concentration. That is, CgA 47-66 below 0.5 mg/kg produced antinociceptive effects, whereas at 2 mg/kg it produced a marked pronociceptive effect. The latter effect was blocked by diltiazem and indomethacin. CgA 47-66-induced antinociceptive effects on AA-induced responses were reversed when the corticotropin-releasing factor (CRF) antagonist alpha-helical CRF 9-41 was i.p. injected to animals prior to AA and CgA 47-66 administration. The administration of i.p. calcitonin gene-related peptide (CGRP) or substance P (SP) evoked dose-dependent abdominal writhing; this effect was abolished when CgA 47-66 was injected. The present data suggest, for the first time, that a fragment of CgA, CgA 47-66, possesses potent antinociceptive effects at low doses. Although the mechanism triggered by this peptide is unknown, CRF receptors are likely to be involved.     

The protective effect of the vagus nerve in a murine model of chronic relapsing colitis

The vagus nerve inhibits the response to systemic administration of endotoxin, and we have recently extended this observation to show that the vagus attenuates acute experimental colitis in mice. The purpose of the present study was to determine whether there is a tonic counterinflammatory influence of the vagus on colitis maintained over several weeks. We assessed disease activity index, macroscopic and histological damage, myeloperoxidase (MPO) activity, and Th1 and Th2 cytokine profiles in chronic colitis induced by administration of dextran sodium sulfate (DSS) in drinking water for three cycles during 5 days with 11 days of rest between each cycle (DSS 3, 2, 2%) in healthy and vagotomized C57BL/6 mice and in mice deficient in macrophage-colony stimulating factor (M-CSF). A pyloroplasty was performed in vagotomized mice. Vagotomy accelerated the onset and the severity of inflammation during the first and second but not the third cycle. Although macroscopic scores were not significantly changed, histological scores as well as MPO activity and colonic tissue levels of IL-1alpha, TNF-alpha, IFN-gamma, and IL-18 but not IL-4 were significantly increased in vagotomized mice compared with sham-operated mice that received DSS. In control mice (without colitis), vagotomy per se did not affect any inflammatory marker. Vagotomy had no effect on the colitis in M-CSF-derived macrophage-deficient mice. These results indicate that the vagus protects against acute relapses on a background of chronic inflammation. Identification of the molecular mechanisms underlying the protective role of parasympathetic nerves opens a new therapeutic avenue for the treatment of acute relapses of chronic inflammatory bowel disease.     

Performance comparison of exome DNA sequencing technologies

Whole exome sequencing by high-throughput sequencing of target-enriched genomic DNA (exome-seq) has become common in basic and translational research as a means of interrogating the interpretable part of the human genome at relatively low cost. We present a comparison of three major commercial exome sequencing platforms from Agilent, Illumina and Nimblegen applied to the same human blood sample. Our results suggest that the Nimblegen platform, which is the only one to use high-density overlapping baits, covers fewer genomic regions than the other platforms but requires the least amount of sequencing to sensitively detect small variants. Agilent and Illumina are able to detect a greater total number of variants with additional sequencing. Illumina captures untranslated regions, which are not targeted by the Nimblegen and Agilent platforms. We also compare exome sequencing and whole genome sequencing (WGS) of the same sample, demonstrating that exome sequencing can detect additional small variants missed by WGS.     

Autoantibodies to endothelial cell surface ATP synthase, the endogenous receptor for hsp60, might play a pathogenic role in vasculatides

Background

Heat shock protein (hsp) 60 that provides “danger signal” binds to the surface of resting endothelial cells (EC) but its receptor has not yet been characterized. In mitochondria, hsp60 specifically associates with adenosine triphosphate (ATP) synthase. We therefore examined the possible interaction between hsp60 and ATP synthase on EC surface.

Methodology/Principal Findings

Using Far Western blot approach, co-immunoprecipitation studies and surface plasmon resonance analyses, we demonstrated that hsp60 binds to the β-subunit of ATP synthase. As a cell surface-expressed molecule, ATP synthase is potentially targeted by anti-EC-antibodies (AECAs) found in the sera of patients suffering vasculitides. Based on enzyme-linked immunosorbent assay and Western blotting techniques with F1-ATP synthase as substrate, we established the presence of anti-ATP synthase antibodies at higher frequency in patients with primary vasculitides (group I) compared with secondary vasculitides (group II). Anti-ATP synthase reactivity from group I patients was restricted to the β-subunit of ATP synthase, whereas those from group II was directed to the α-, β- and γ-subunits. Cell surface ATP synthase regulates intracellular pH (pHi). In low extracellular pH medium, we detected abnormal decreased of EC pHi in the presence of anti-ATP synthase antibodies, irrespective of their fine reactivities. Interestingly, soluble hsp60 abrogated the anti-ATP synthase-induced pHi down-regulation.

Conclusions/Significance

Our results indicate that ATP synthase is targeted by AECAs on the surface of EC that induce intracellular acidification. Such pathogenic effect in vasculitides can be modulated by hsp60 binding on ATP synthase which preserves ATP synthase activity.