Melatonin as a central molecule connecting neural development and calcium signaling

Melatonin (MEL) is a neuroendocrine hormone secreted by the pineal gland in association with the suprachiasmatic nucleus and peripheral tissues. MEL has been observed to play a critical role in the reproductive process and in the fetomaternal interface. Extrapineal synthesis has been reported in mammalian models during pregnancy, especially by the placenta tissue. MEL can regulate intracellular processes (e.g., G-proteins) and the activity of second messengers (e.g., cAMP, IP_3, Ca²⁺). During neurodevelopment, these activities regulated by melatonin have an important role as an intracellular signaling for gene expression regulation. To review the role of MEL in neurodevelopment, we built interactome networks of different proteins that act in these processes using systems biology tools. The analyses of interactome networks revealed that MEL could modulate neurodevelopment through the regulation of Ca²⁺ intracellular levels and influencing BMP/SMAD signaling, thus affecting neural gene responses and neuronal differentiation.     

Characterisation of structural genes involved in phytic acid biosynthesis in common bean (<Emphasis Type="Italic">Phaseolus vulgaris</Emphasis> L.)

Phytate (myo-inositol hexakisphosphate), the major form of phosphorous storage in plant seeds, is an inositol phosphate compound poorly digested by humans and monogastric animals. A major goal for grain crop improvement is the reduction of its content in the seed to improve micronutrient bioavailability and phosphorus utilisation by humans and non-ruminant animals, respectively. We are interested in lowering phytic acid in common bean seed and to this goal we have undertaken a two-strategy approach: the isolation of mutants from an EMS mutagenised population (Campion et al. 2009) and the identification of genes coding for candidate enzymes involved in inositol phosphate metabolism for future targeted mutant isolation and/or study. In this paper we report data referred to the second approach and concerning the isolation and genomic organisation of Phaseolus vulgaris genes coding for myo-inositol 1-phosphate synthase (PvMIPSs and PvMIPSv), inositol monophosphatase (PvIMP), myo-inositol kinase (PvMIK), inositol 1,4,5-tris-phosphate kinase (PvIPK2), inositol 1,3,4-triphosphate 5/6-kinase (PvITPKα and PvITPKβ) and inositol 1,3,4,5,6 pentakisphosphate 2-kinase (PvIPK1). All these genes have been mapped on the common bean reference genetic map of McClean (NDSU) 2007 using a virtual mapping strategy. Bean markers, presumably associated to each gene of the phytic acid pathway, have also been identified. In addition, we provide a picture of the expression, during seed development, of the genes involved in phytic acid synthesis, including those such as MIK, IMP and IPK2, for which this information was lacking.     

Experimental small-scale grassland fragmentation alters competitive interactions among ant species

Different species may respond differently to habitat fragmentation. Theory predicts that abundant generalist species should be less affected by fragmentation than specialist species. In ant communities, the most abundant species is often behaviourally dominant. Thus, habitat fragmentation could alter competitive interactions between the dominant ant species and the other species. We tested this hypothesis in a long-term grassland fragmentation experiment. Fragments of different size (20.25 and 2.25 m²) were isolated by a 5-m wide strip of frequently mown vegetation. Control plots were situated in adjacent undisturbed grassland. Ant density and species composition were assessed 3 and 6 years after initiation of the experimental fragmentation. The effect of the dominant ant species on the resource use of the other species was examined at natural sugar resources (aphids and extrafloral nectaries) and at artificial sugar baits. Lasius paralienus was the most abundant ant species (72% of nests) in the grasslands examined. Species richness and forager density in the other species decreased with increasing density of L. paralienus in fragments but not in control plots. The overall forager density of the other species was positively related to their habitat niche overlap with L. paralienus. The density of foragers of the other species at sugar resources was not affected by L. paralienus forager density. The experimental fragmentation resulted in an increase in natural sugar resources in fragments. This may have reduced the intensity of interspecific competition for sugar resources. Our study shows that the grassland fragmentation altered interactions between the dominant L. paralienus and the other ant species.Electronic Supplementary Material Supplementary material is available for this article at     

Collagen and elastin cross-linking: a mechanism of constrictive remodeling after arterial injury

Constrictive remodeling after arterial injury is related to collagen accumulation. Cross-linking has been shown to induce a scar process in cutaneous wound healing and is increased after arterial injury. We therefore evaluated the effect of cross-linking inhibition on qualitative and quantitative changes in collagen, elastin, and arterial remodeling after balloon injury in the atherosclerotic rabbit model. Atherosclerotic-like lesions were induced in femoral arteries of 28 New Zealand White rabbits by a combination of air desiccation and a high-cholesterol diet. After 1 mo, balloon angioplasty was performed in both femoral arteries. Fourteen rabbits were fed beta-aminopropionitrile (beta-APN, 100 mg/kg) and compared with 14 untreated animals. The remodeling index, i.e., the ratio of external elastic lamina at the lesion site to external elastic lamina at the reference site, was determined 4 wk after angioplasty for both groups. Pyridinoline was significantly decreased in arteries from beta-APN-treated animals compared with controls, confirming inhibition of collagen cross-linking: 0.30 (SD 0.03) and 0.52 (SD 0.02) mmol/mol hydroxyproline, respectively (P = 0.002). Scanning and transmission electron microscopy showed a profound disorganization of collagen fibers in arteries from beta-APN-treated animals. The remodeling index was significantly higher in beta-APN-treated than in control animals [1.1 (SD 0.3) vs. 0.8 (SD 0.3), P = 0.03], indicating favorable remodeling. Restenosis decreased by 33% in beta-APN-treated animals: 32% (SD 16) vs. 48% (SD 24) (P = 0.02). Neointimal collagen density was significantly lower in beta-APN-treated animals than in controls: 23.0% (SD 3.8) vs. 29.4% (SD 4.0) (P = 0.004). These findings suggest that collagen and elastin cross-linking plays a role in the healing process via constrictive remodeling and restenosis after balloon injury in the atherosclerotic rabbit model.     

Polymerase chain reaction assay specific for pathogenic Leptospira based on the gene hap1 encoding the hemolysis-associated protein-1

In this study, we used Southern hybridization of genomic DNA with the integral hap1 gene as a probe to show that this gene is only present in pathogenic Leptospira strains. We then selected PCR primers based on the hap1 gene, and tested them on several Leptospira strains and biological samples. Specific amplification was obtained for all pathogenic strains tested. Negative PCR results were observed with all saprophytic leptospire strains used as well as with other spirochetes and bacteria commonly found in biological samples. The results of direct PCR performed on biological samples, such as blood, urine or kidneys correlated with the results obtained with the classical Leptospira tests (culture and MAT). A PCR assay based on this gene would be a very useful tool for the rapid, sensitive and specific identification of pathogenic leptospires in samples for diagnosis or epidemiological survey.     

WT1 CpG islands methylation in human lung cancer: A pilot study

Background

CpG island hypermethylation of gene promoters and regulatory regions is a well-known mechanism of epigenetic silencing of tumor suppressors and is directly linked to carcinogenesis. Wilm’s tumor gene (WT1) is a tumor suppressor protein involved in the regulation of human cell growth and differentiation and a modulator of oncogenic K Ras signaling in lung cancer. Changes in the pattern of methylation of the WT1 gene have not yet been studied in detail in human lung cancer. In this study we compared the methylation profile of WT1 gene in samples of neoplastic and non-neoplastic lung tissue taken from the same patients.

Methods

DNA was extracted from neoplastic and normal lung tissue obtained from 16 patients with non small cell lung cancer (NSCLC). The methylation status of 29 CpG islands in the 5′ region of WT1 was determined by pyrosequencing. Statistical analysis was carried out by T test and Mann Whitney test.

Results

The mean percentage of methylation, considering all CpG islands of WT1 in the neoplastic tissues of the 16 NSCLC patients, was 16.2 ± 3.4, whereas in the normal lung tissue from the same patients it was 5.6 ± 1.7 (p < 0.001). Adenocarcinomas presented higher methylation levels than squamous cell carcinomas (p < 0,001).

Conclusions

Methylation of WT1 gene is significantly increased in NSCLC. Both histotype and exposure to cigarette smoke heavily influence the pattern of CpG islands which undergo hypermethylation.     

Oestrogènes et reproduction masculine

The role of estrogen on male reproductive function has become clearer in the last decade. During these years the study of the effect of testosterone, estrogen or an aromatase inhibitor in hypogonadal men provided a first evidence of the effects of estrogens in the regulation of gonadotropin secretion. At the same time, the development of a line of transgenic male mice lacking estrogen receptor α, estrogen receptor β or aromatase gene provided further evidence about the role of estrogens not only in the regulation of gonadotropin secretion, but also on the effects of estrogens on testicular function and development. A confirmation of these actions of estrogens came from the observation of naturally occurring mutations of the estrogen receptor and of the aromatase gene in human males. Based on these data it has been demonstrated that estrogens are major regulators of gonadotropin secretion acting both at pituitary and hypotalamic level. The presence in the human reproductive structures of estrogen receptor α, estrogen receptor β and the aromatase enzyme indicates the existence of receptor α, estrogen receptor β or aromatase estrogen actions at this level. Anyway, the precise role of estrogens in testicular development and function and on the regulation of human spermatogenesis has not yet been precisely clarified.     

Aiming off the target: recycling target capture sequencing reads for investigating repetitive DNA

Background and AimsWith the advance of high-throughput sequencing, reduced-representation methods such as target capture sequencing (TCS) emerged as cost-efficient ways of gathering genomic information, particularly from coding regions. As the off-target reads from such sequencing are expected to be similar to genome skimming (GS), we assessed the quality of repeat characterization in plant genomes using these data.MethodsRepeat composition obtained from TCS datasets of five Rhynchospora (Cyperaceae) species were compared with GS data from the same taxa. In addition, a FISH probe was designed based on the most abundant satellite found in the TCS dataset of Rhynchospora cephalotes. Finally, repeat-based phylogenies of the five Rhynchospora species were constructed based on the GS and TCS datasets and the topologies were compared with a gene-alignment-based phylogenetic tree.Key ResultsAll the major repetitive DNA families were identified in TCS, including repeats that showed abundances as low as 0.01 % in the GS data. Rank correlations between GS and TCS repeat abundances were moderately high (r = 0.58–0.85), increasing after filtering out the targeted loci from the raw TCS reads (r = 0.66–0.92). Repeat data obtained by TCS were also reliable in developing a cytogenetic probe of a new variant of the holocentromeric satellite Tyba. Repeat-based phylogenies from TCS data were congruent with those obtained from GS data and the gene-alignment tree.ConclusionsOur results show that off-target TCS reads can be recycled to identify repeats for cyto- and phylogenomic investigations. Given the growing availability of TCS reads, driven by global phylogenomic projects, our strategy represents a way to recycle genomic data and contribute to a better characterization of plant biodiversity.     

Perception of Antiretroviral Generic Medicines: One-Day Survey of HIV-Infected Patients and Their Physicians in France

BackgroundIn the interest of cost effectiveness, switching antiretroviral brand name medications to generics is recommended in France since 2013. The study objective was to evaluate the perception of generics per se and antiretroviral generics in HIV-infected patients and their hospital physiciansConclusionsAcceptability of antiretroviral generics in this French population was mostly dictated by the patient’s and physician’s knowledge and use of generics overall. It should be improved with an efficient information of both patients and physicians.