Clinical chemistry reference database for Wistar rats and C57/BL6 mice

Clinical chemistry data are decisive for evaluating altered organ function or damage in experimental animals. Few publications provide reliable clinical chemistry reference intervals, and analytical methods are often not described. Here, we investigated common clinical chemistry values in adult male and female Wistar rats and C57/BL6 mice (n=30/group). Blood samples were taken and analysed for electrolytes, substrates, metabolites and enzymes. In addition, we investigated cystatin C, an important marker of glomerular dysfunction. All data were obtained using commercially available kits frequently employed in most clinical chemistry laboratories and compared with data from other studies, as well as with human data. Significant gender-specific differences were observed in rats (electrolytes, retention parameters and transaminases) and in mice (cholesterol, glucose). High variability was noted for sodium, potassium, glucose, creatine kinase, lactate dehydrogenase and transaminase levels. Both rodent species showed markedly higher alpha-amylase activity than humans. This report demonstrates significant differences between genders for many analytes in rats and for fewer parameters in mice. Some reference values displayed major discrepancies between rodents and humans.     

12S-lipoxygenase protein associates with alpha-actin fibers in human umbilical artery vascular smooth muscle cells

The current study sets out to characterize the intracellular localization of the platelet-type 12S-lipoxygenase (12-LO), an enzyme involved in angiotensin-II induced signaling in vascular smooth muscle cells (VSMC). Immunohistochemical analysis of VSMC in vitro or human umbilical arteries in vivo showed a clear cytoplasmic localization. On immunogold electron microscopy, 12-LO was found primarily associated with cytoplasmic VSMC muscle fibrils. Upon angiotensin-II treatment of cultured VSMC, immunoprecipitated 12-LO was found bound to alpha-actin, a component of the cytoplasmic myofilaments. 12-LO/alpha-actin binding was blocked by VSMC pretreatment with the 12-LO inhibitors, baicalien or esculetine and the protein synthesis inhibitor, cycloheximide. Moreover, the binding of 12-LO to alpha-actin was not associated with 12-LO serine or tyrosine phosphorylation. These observations suggest a previously unrecognized angiotensin-II dependent protein interaction in VSMC through which 12-LO protein may be trafficked, for yet undiscovered purposes towards the much more abundantly expressed cytoskeletal protein alpha-actin.     

Photoacoustics: a novel tool for the determination of photosynthetic energy storage efficiency in phytoplankton

Photosynthetic energy storage efficiency controls the development and decline of phytoplankton biomass. All abiotic environmental factors such as light intensity; temperature, nutrient availability and pollutants will exert detectable changes in the photosynthetic energy storage efficiency of phytoplankton, and subsequently affect total biomass and composition of phytoplankton assemblages. Since this efficiency is a sensitive amplifier of ambient conditions, it thereby is an excellent reporter of water quality parameter. We demonstrate the applicability of the novel photoacoustic method in easily and directly estimating the energy storage efficiency of phytoplankton in a drinking water reservoir of different nutrient status. Electronic Supplementary Material Supplementary material is available in the online version of this article at and accessible for authorised users Handling editor: J. Padisak     

MetaQC: objective quality control and inclusion/exclusion criteria for genomic meta-analysis

Genomic meta-analysis to combine relevant and homogeneous studies has been widely applied, but the quality control (QC) and objective inclusion/exclusion criteria have been largely overlooked. Currently, the inclusion/exclusion criteria mostly depend on ad-hoc expert opinion or naïve threshold by sample size or platform. There are pressing needs to develop a systematic QC methodology as the decision of study inclusion greatly impacts the final meta-analysis outcome. In this article, we propose six quantitative quality control measures, covering internal homogeneity of coexpression structure among studies, external consistency of coexpression pattern with pathway database, and accuracy and consistency of differentially expressed gene detection or enriched pathway identification. Each quality control index is defined as the minus log transformed P values from formal hypothesis testing. Principal component analysis biplots and a standardized mean rank are applied to assist visualization and decision. We applied the proposed method to 4 large-scale examples, combining 7 brain cancer, 9 prostate cancer, 8 idiopathic pulmonary fibrosis and 17 major depressive disorder studies, respectively. The identified problematic studies were further scrutinized for potential technical or biological causes of their lower quality to determine their exclusion from meta-analysis. The application and simulation results concluded a systematic quality assessment framework for genomic meta-analysis.     

Alternate Bearing in Citrus: Changes in the Expression of Flowering Control Genes and in Global Gene Expression in ON- versus OFF-Crop Trees

Alternate bearing (AB) is the process in fruit trees by which cycles of heavy yield (ON crop) one year are followed by a light yield (OFF crop) the next. Heavy yield usually reduces flowering intensity the following year. Despite its agricultural importance, how the developing crop influences the following year''s return bloom and yield is not fully understood. It might be assumed that an ‘AB signal’ is generated in the fruit, or in another organ that senses fruit presence, and moves into the bud to determine its fate—flowering or vegetative growth. The bud then responds to fruit presence by altering regulatory and metabolic pathways. Determining these pathways, and when they are altered, might indicate the nature of this putative AB signal. We studied bud morphology, the expression of flowering control genes, and global gene expression in ON- and OFF-crop buds. In May, shortly after flowering and fruit set, OFF-crop buds were already significantly longer than ON-crop buds. The number of differentially expressed genes was higher in May than at the other tested time points. Processes differentially expressed between ON- and OFF-crop trees included key metabolic and regulatory pathways, such as photosynthesis and secondary metabolism. The expression of genes of trehalose metabolism and flavonoid metabolism was validated by nCounter technology, and the latter was confirmed by metabolomic analysis. Among genes induced in OFF-crop trees was one homologous to SQUAMOSA PROMOTER BINDING-LIKE (SPL), which controls juvenile-to-adult and annual phase transitions, regulated by miR156. The expression pattern of SPL-like, miR156 and other flowering control genes suggested that fruit load affects bud fate, and therefore development and metabolism, a relatively long time before the flowering induction period. Results shed light on some of the metabolic and regulatory processes that are altered in ON and OFF buds.     

The α7 Nicotinic Acetylcholine Receptor Agonist GTS-21 Improves Bacterial Clearance in Mice by Restoring Hyperoxia-Compromised Macrophage Function

Mechanical ventilation with supraphysiological concentrations of oxygen (hyperoxia) is routinely used to treat patients with respiratory distress. However, prolonged exposure to hyperoxia compromises the ability of the macrophage to phagocytose and clear bacteria. Previously, we showed that the exposure of mice to hyperoxia elicits the release of the nuclear protein high mobility group box-1 (HMGB1) into the airways. Extracellular HMGB1 impairs macrophage phagocytosis and increases the mortality of mice infected with Pseudomonas aeruginosa (PA). The aim of this study was to determine whether GTS-21 [3-(2,4 dimethoxybenzylidene)-anabaseine dihydrochloride], an α7 nicotinic acetylcholine receptor (α7nAChR) agonist, could inhibit hyperoxia-induced HMGB1 release into the airways, enhance macrophage function and improve bacterial clearance from the lungs in a mouse model of ventilator-associated pneumonia. GTS-21 (0.04, 0.4 and 4 mg/kg) or saline was systemically administered via intraperitoneal injection to mice that were exposed to hyperoxia (≥99% O₂) and subsequently challenged with PA. We found that systemic administration of 4 mg/kg GTS-21 significantly increased bacterial clearance, decreased acute lung injury and decreased accumulation of airway HMGB1. To investigate the cellular mechanism of these observations, RAW 264.7 cells, a macrophagelike cell line, were incubated with different concentrations of GTS-21 in the presence of 95% O₂. The phagocytic activity of macrophages was significantly increased by GTS-21 in a dose-dependent manner. In addition, hyperoxia-induced hyperacetylation of HMGB1 was significantly reduced in macrophages incubated with GTS-21. Furthermore, GTS-21 significantly inhibited the cytoplasmic translocation and release of HMGB1 from these macrophages. Our results indicate that GTS-21 is effective in improving bacterial clearance and reducing acute lung injury by enhancing macrophage function via inhibiting the release of nuclear HMGB1. Therefore, the α7nAChR represents a possible pharmacological target to improve the clinical outcome of patients on ventilators by augmenting host defense against bacterial infections.     

BL-7010 Demonstrates Specific Binding to Gliadin and Reduces Gluten-Associated Pathology in a Chronic Mouse Model of Gliadin Sensitivity

Celiac disease (CD) is an autoimmune disorder in individuals that carry DQ2 or DQ8 MHC class II haplotypes, triggered by the ingestion of gluten. There is no current treatment other than a gluten-free diet (GFD). We have previously shown that the BL-7010 copolymer poly(hydroxyethyl methacrylate-co-styrene sulfonate) (P(HEMA-co-SS)) binds with higher efficiency to gliadin than to other proteins present in the small intestine, ameliorating gliadin-induced pathology in the HLA-HCD4/DQ8 model of gluten sensitivity. The aim of this study was to investigate the efficiency of two batches of BL-7010 to interact with gliadin, essential vitamins and digestive enzymes not previously tested, and to assess the ability of the copolymer to reduce gluten-associated pathology using the NOD-DQ8 mouse model, which exhibits more significant small intestinal damage when challenged with gluten than HCD4/DQ8 mice. In addition, the safety and systemic exposure of BL-7010 was evaluated in vivo (in rats) and in vitro (genetic toxicity studies). In vitro binding data showed that BL-7010 interacted with high affinity with gliadin and that BL-7010 had no interaction with the tested vitamins and digestive enzymes. BL-7010 was effective at preventing gluten-induced decreases in villus-to-crypt ratios, intraepithelial lymphocytosis and alterations in paracellular permeability and putative anion transporter-1 mRNA expression in the small intestine. In rats, BL-7010 was well-tolerated and safe following 14 days of daily repeated administration of 3000 mg/kg. BL-7010 did not exhibit any mutagenic effect in the genetic toxicity studies. Using complementary animal models and chronic gluten exposure the results demonstrate that administration of BL-7010 is effective and safe and that it is able to decrease pathology associated with gliadin sensitization warranting the progression to Phase I trials in humans.     

Correction to: Exposing the hidden half: root research at the forefront of science

Plant and Soil - In the published version of this editorial paper, the sentence in the first paragraph should be corrected as shown below.