Colonic Mucosal Proteome Signature Reveals Reduced Energy Metabolism and Protein Synthesis but Activated Autophagy during Anorexia‐Induced Malnutrition in Mice

Anorexia nervosa is an eating disorder often associated with intestinal disorders. To explore the underlying mechanisms of these disorders, the colonic proteome was evaluated during activity‐based anorexia. Female C57Bl/6 mice were randomized into three groups: Control, Limited Food Access (LFA) and Activity‐Based Anorexia (ABA). LFA and ABA mice had a progressive limited access to food but only ABA mice had access to an activity wheel. On colonic mucosal protein extracts, a 2D PAGE‐based comparative proteomic analysis was then performed and differentially expressed proteins were identified by LC‐ESI‐MS/MS. Twenty‐seven nonredundant proteins that were differentially expressed between Control, LFA, and ABA groups were identified. ABA mice exhibited alteration of several mitochondrial proteins involved in energy metabolism such as dihydrolipoyl dehydrogenase and 3‐mercaptopyruvate sulfurtransferase. In addition, a downregulation of mammalian target of rapamycin (mTOR) pathway was observed leading, on the one hand, to the inhibition of protein synthesis, evaluated by puromycin incorporation and mediated by the increased phosphorylation of eukaryotic elongation factor 2, and on the other hand, to the activation of autophagy, assessed by the increase of the marker of autophagy, form LC3‐phosphatidylethanolamine conjugate/Cytosolic form of Microtubule‐associated protein 1A/1B light chain 3 (LC3II/LC3I) ratio. Colonic mucosal proteome is altered during ABA suggesting a downregulation of energy metabolism. A decrease of protein synthesis and an activation of autophagy were also observed mediated by mTOR pathway.     

Identification of Antibiotic Resistance Cassettes in Class 1 Integrons in Aeromonas spp. Strains Isolated From Fresh Fish (Cyprinus carpio L.)

Forty-six Aeromonas spp. strains were isolated from fresh fish and investigated for their antimicrobial susceptibility, detection of Class 1 integrons by PCR, and arrangement of gene cassettes. Selected isolates were further characterized by enterobacterial repetitive intergenic consensus-PCR. Twenty isolates were found to carry Class 1 integrons. Amplification of the variable regions of the integrons revealed diverse bands ranging in size from 150 to 1,958 pb. Sequence analysis of the variable regions revealed the presence of several gene cassettes, such as adenylyl transferases (aadA2 and aadA5), dihydrofolate reductases (dfrA17 and dfrA1), chloramphenicol acetyl transferase (catB3), β-lactamase (oxa2), lincosamide nucleotidil transferase (linF), aminoglycoside-modifying enzyme (apha15), and oxacillinase (bla _OXA-10). Two open reading frames with an unknown function were identified as orfC and orfD. The aadA2 cassette was the most common integron found in this study. Interestingly, five integrons were detected in the plasmids that might be involved in the transfer of resistance genes to other bacteria. This is a first report of cassette encoding for lincosamides (linF) resistance in Aeromonas spp. Implications on the incidence of integrons in isolates of Aeromonas spp. from fresh fish for human consumption, and its possible consequences to human health are discussed.     

Dormancy and dispersal as mediators of zooplankton population and community dynamics along a hydrological disturbance gradient in inland temporary pools

At some stage in their life cycle, most zooplankton in temporary waters produce dormant eggs that assemble in a persistent egg bank to cope with unfavourable conditions. As part of a risk-spreading strategy, only a fraction of the egg bank hatches during a single inundation. Besides this dispersal in time, resistant dormant eggs also disperse in space via vectors including wind, water and animals. The structure and functioning of the dormant egg bank has important consequences for (meta) population and (meta) community structure and dynamics. Here, we merge empirical and theoretical data into a conceptual framework for the study of population and community responses in temporary ponds along a gradient in hydrological disturbance. Overall, we conclude that changes in hydrological disturbance may compromise both the abiotic (i.e. water quality) and biotic (i.e. population and community processes) integrity of temporary pools which is especially relevant in light of ongoing anthropogenic alterations in the hydrology of inland waters.     

Lactobacillus paracasei subsp. paracasei 8700:2 Degrades Inulin-Type Fructans Exhibiting Different Degrees of Polymerization

Ten strains of lactobacilli were assessed for their capacity to degrade inulin-type fructans, which are well-known prebiotics. Both oligofructose and inulin were tested. The dairy isolate Lactobacillus acidophilus IBB 801 degraded only oligofructose. The human isolate Lactobacillus paracasei subsp. paracasei 8700:2 degraded oligofructose and long-chain inulin and grew rapidly on both energy sources. In both cases, fractions of different degrees of polymerization were fermented. Moreover, large and short fractions of oligofructose were degraded simultaneously. When L. paracasei subsp. paracasei 8700:2 grew on oligofructose-enriched inulin, oligofructose was preferentially metabolized. In all cases, lactic acid was the main metabolic end product. Significant amounts of acetic acid, formic acid, and ethanol were produced when long-chain inulin or oligofructose-enriched inulin was used as the sole energy source.     

Cold tolerance of the harlequin ladybird Harmonia axyridis in Europe

As an essential aspect of its invasive character in Europe, this study examined the cold hardiness of the harlequin ladybird Harmonia axyridis. This was done for field-collected populations in Belgium overwintering either in an unheated indoor or an outdoor hibernaculum. The supercooling point, lower lethal temperature and lower lethal time at 0 and −5 °C were determined. Possible seasonal changes were taken into account by monitoring the populations during each winter month. The supercooling point and lower lethal temperature remained relatively constant for the overwintering populations in the outdoor hibernaculum, ranging from −17.5 to −16.5 °C and −17.1 to −16.3 °C, respectively. In contrast, the supercooling point and lower lethal temperature of the population overwintering indoors clearly increased as the winter progressed, from −18.5 to −13.2 °C and −16.7 to −14.1 °C, respectively. A proportion of the individuals overwintering indoors could thus encounter problems surviving the winter due to premature activation at times when food is not available. The lower lethal time of field populations at 0 and −5 °C varied from 18 to 24 weeks and from 12 to 22 weeks, respectively. Morph type and sex had no influence on the cold hardiness of the overwintering adults. In addition, all cold tolerance parameters differed greatly between the laboratory population and field populations, implying that cold tolerance research based solely on laboratory populations may not be representative of field situations. We conclude from this study that the strong cold hardiness of H. axyridis in Europe may enable the species to establish in large parts of the continent.     

Structural bases for heme binding and diatomic ligand recognition in truncated hemoglobins

Truncated hemoglobins (trHbs) are low-molecular-weight oxygen-binding heme-proteins distributed in eubacteria, cyanobacteria, unicellular eukaryotes, and in higher plants, constituting a distinct group within the hemoglobin (Hb) superfamily. TrHbs display amino acid sequences 20-40 residues shorter than classical (non)vertebrate Hbs and myoglobins, to which they are scarcely related by sequence similarity. The trHb tertiary structure is based on a 2-on-2 alpha-helical sandwich, which represents a striking editing of the highly conserved 3-on-3 alpha-helical globin fold, achieved through deletion/truncation of alpha-helices and specific residue substitutions. Despite their 'minimal' polypeptide chain span, trHbs display an inner tunnel/cavity system held to support ligand diffusion to/from the heme distal pocket, accumulation of heme ligands within the protein matrix, and/or multiligand reactions. Moreover, trHbs bind and effectively stabilize the heme and recognize diatomic ligands (i.e., O2, CO, NO, and cyanide), albeit with varying thermodynamic and kinetic parameters. Here, structural bases for heme binding and diatomic ligand recognition by trHbs are reviewed.     

Relationship of bursal anti-steroidogenic peptide (BASP) and histone H1

Previous in vitro research from our laboratory has demonstrated the existence of a protein purified from the chicken bursa of Fabricius, with potent antisteroidogenic and antiproliferative action on granulose cells and lymphocytes, respectively called Bursal anti-steroidogenic peptide (BASP). This protein is heat-labile, basic, and amino- and carboxy-terminus blocked. In highly purified form, the protein presents as a doublet on SDS-PAGE electrophoresis with an apparent MW of approximately 29 and approximately 32 kDa. Recently, Nanoflow Q-TOF Mass Spectrometry amino acid sequencing allowed determination of a convincing partial amino acid sequence, strongly suggesting a probable relationship of BASP with histone H1. Bursal cDNA expression library screening, using an antibody produced against BASP, also identified a clone with a sequence matching histone H1. Presently, we have demonstrated that SDS-PAGE electrophoresis of highly purified and bioactive BASP, and commercially-available calf thymus derived histone H1, produced similar doublets at approximately the same apparent MW, and that the electrophoretic profile of these 2 preparations were strikingly similar following 2 dimensional gel electrophoresis. The BASP doublet produced on SDS-PAGE was recognized by a commercially available monoclonal antibody recognizing a highly conserved region of histone H1. Furthermore, calf thymus histone H1 was found to suppress mitogen-stimulated chicken B-cell proliferation in a concentration-related manner, similar to the action of BASP. These data indicate that BASP shares substantial structural homology with, and may be identical to, histone H1.     

Livestock disturbances in Mediterranean temporary ponds: A mesocosm experiment with sheep manure and simulated trampling

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