Exposure to genotoxic agents, host factors, and lifestyle influence the number of centromeric signals in micronuclei: a pooled re-analysis

We pooled data from three biomonitoring studies using the cytokinesis-block micronucleus assay in peripheral blood lymphocytes in combination with fluorescence in situ hybridization. Centromere-positive micronuclei (C+MN) were classified in two groups: those containing one centromere (C1+MN) and those with two or more (Cx+MN). The three studies evaluated untreated cancer patients, welders, and pathologists/anatomists exposed to formaldehyde. The total number of subjects included in the pooled re-analysis was 113. A higher frequency of C+MN was observed in cancer patients and exposed workers, who showed significant differences from controls in all studies. C1+MN were particularly increased in the group of pathologists/anatomists, who showed a 3.29 times higher frequency than controls (95% CI: 2.04-5.30). A borderline increase in Cx+MN was observed in welders when compared to the corresponding control group (FR: 1.31; 95% CI: 0.99-1.74). An evident effect of gender was found, with significantly increased frequencies of all endpoints measuring aneuploidy in females (C+MN, C1+MN, and Cx+MN). Alcohol consumption had a significant effect on total MN frequency and particularly on C+MN and C1+MN. In conclusion, scoring the number of centromeric signals in the micronucleus assay provides additional information about the mechanism of action of various genotoxic agents, and the role of confounding factors may be more specifically accounted for. Indeed, C+MN could be efficiently used in biomonitoring studies as an independent biomarker of exposure and early biological effect. The use of centromeric signals allows the identification of two further endpoints, representing two alternative pathways of chromosome loss, i.e., impaired chromosome migration, leading to increased C1+MN frequency, and centrosome amplification, possibly leading to Cx+MN with two or more centromeric signals.     

Trifunctional norrisolide probes for the study of Golgi vesiculation

Inspired by the effect of norrisolide on the Golgi complex, we synthesized norrisolide probes that contain: the perhydroindane core of the parent natural product for Golgi localization, a crosslinking unit (aryl azide or epoxide) for covalent binding to the target, and a tag (biotin or iodine) for subsequent target purification. We found that biotin-containing probes 14, 20 and 24 induced inefficient Golgi vesiculation. However, the iodinated probe 25 induced extensive and irreversible Golgi fragmentation. This probe can be used for the isolation of the cellular target of norrisolide.     

Design, synthesis, and biological evaluation of new (2E,6E)-10-(dimethylamino)-3,7-dimethyl-2,6-decadien-1-ol ethers as inhibitors of human and Trypanosoma cruzi oxidosqualene cyclase

New dimethylamino truncated squalene ether derivatives containing a different aromatic moiety (phenyl, naphthyl, and biphenyl) or a simple alkyl (n-hexylic) group were synthesized as inhibitors of the oxidosqualene cyclase (OSC) and of the sterol biosynthetic pathway. The activity against human OSC was compared with the activity against the OSCs of pathogenic organisms such as Pneumocystis carinii and Trypanosoma cruzi. The phenyl derivative was the most potent inhibitor of T. cruzi OSC.     

The minimum information required for reporting a molecular interaction experiment (MIMIx)

A wealth of molecular interaction data is available in the literature, ranging from large-scale datasets to a single interaction confirmed by several different techniques. These data are all too often reported either as free text or in tables of variable format, and are often missing key pieces of information essential for a full understanding of the experiment. Here we propose MIMIx, the minimum information required for reporting a molecular interaction experiment. Adherence to these reporting guidelines will result in publications of increased clarity and usefulness to the scientific community and will support the rapid, systematic capture of molecular interaction data in public databases, thereby improving access to valuable interaction data.     

Targeting farnesoid X receptor for liver and metabolic disorders

The farnesoid X receptor (FXR) is a metabolic nuclear receptor expressed in the liver, intestine, kidney and adipose tissue. By regulating the expression and function of genes involved in bile acid (BA) synthesis, uptake and excretion, FXR has emerged as a key gene involved in the maintenance of cholesterol and BA homeostasis. FXR ligands are currently under clinical investigation for the treatment of cholestasis, dyslipidemic disorders and conditions of insulin resistance in type 2 diabetes and non-alcoholic steatohepatitis (NASH). Because activation of FXR impacts a considerable number of genes, development of FXR modulators that selectively regulate specific pathways will limit potentially undesirable side effects. Interaction of FXR with other BAs and xenobiotics sensors such as the constitutive androstane receptor and the pregnane X receptor might allow the development of combination therapies for liver and metabolic disorders.     

Investigation on the Origin of Sperm DNA Fragmentation: Role of Apoptosis,Immaturity and Oxidative Stress

Sperm DNA fragmentation (sDF) represents a threat to male fertility, human reproduction and the health of the offspring. The causes of sDF are still unclear, even if apoptosis, oxidative assault and defects in chromatin maturation are hypothesized. Using multicolor flow cytometry and sperm sorting, we challenged the three hypothesized mechanisms by simultaneously evaluating sDF and signs of oxidative damage (8-hydroxy, 2′-deoxyguanosine [8-OHdG] and malondialdehyde [MDA]), apoptosis (caspase activity and cleaved poly[ADP-ribose] polymerase [cPARP]) and sperm immaturity (creatine phosphokinase [CK] and excess of residual histones). Active caspases and c-PARP were concomitant with sDF in a high percentage of spermatozoa (82.6% ± 9.1% and 53.5% ± 16.4%, respectively). Excess of residual histones was significantly higher in DNA-fragmented sperm versus sperm without DNA fragmentation (74.8% ± 17.5% and 37.3% ± 16.6%, respectively, p < 0.005), and largely concomitant with active caspases. Conversely, oxidative damage was scarcely concomitant with sDF in the total sperm population, at variance with live sperm, where 8-OHdG and MDA were clearly associated to sDF. In addition, most live cells with active caspase also showed 8-OHdG, suggesting activation of apoptotic pathways in oxidative-injured live cells. This is the first investigation on the origin of sDF directly evaluating the simultaneous presence of the signs of the hypothesized mechanisms with DNA breaks at the single cell level. The results indicate that the main pathway leading to sperm DNA breaks is a process of apoptosis, likely triggered by an impairment of chromatin maturation in the testis and by oxidative stress during the transit in the male genital tract. These findings are highly relevant for clinical studies on the effects of drugs on sDF and oxidative stress in infertile men and for the development of new therapeutic strategies.     

Performance of a mobile mechanical screen to improve the commercial quality of wood chips for energy

The study analyzed the performance of a mobile screening device for upgrading coarse wood chips to residential user standards, by removing oversize particles and fines. The machine was designed for transportation to forest landings, logistic terminals and plant chip yards. Average productivity was 1.9 oven-dry tons (odt) h⁻¹, corresponding to a screening cost of 28.5 € odt⁻¹. This figure was lower than the price increase obtained by upgrading industrial chips to residential user standards. Hence, screening offered a profit of 4.7 € odt⁻¹, or 16% of the original screening cost. The screening process was capable of upgrading chips from industrial to residential specifications, by reducing the incidence of oversize particles below the 1% critical threshold. Screening also allowed a substantial reduction in the content of fines. A similar effect was not verified for crushed wood, which failed to meet the specifications for residential fuel.