Isolation and characterization of microsatellite markers in Acca sellowiana (Berg) Burret

Acca sellowiana has commercial potential due to the quality and the unique flavor of its fruit. Conservation of natural populations and management of breeding programmes would benefit from the availability of molecular markers that could be used to characterize levels and distribution of genetic variability. Thus, 13 microsatellite markers were developed from an enriched genomic library of A. sellowiana. They were characterized using 40 samples. The expected and observed heterozygosities ranged from 0.513 to 0.913 and from 0.200 to 0.889, respectively. These are the first microsatellite loci characterized from A. sellowiana that will contribute to improve researches on its genetic conservation, characterization and breeding.     

Effects of nutritional stress during lactation on immunity costs and indices of future reproduction in Iberian red deer (Cervus elaphus hispanicus)

Nutrition may affect the balance between immunity and traits such as reproduction or growth. This study examines the effect of low nutrient availability on immunity indices and lactation in captive Iberian red deer. Twelve hinds and their calves were allotted to a food-restricted (50-60% daily energy requirements) or a control group just after calving. Low calorie intake exerted a greater effect on the immunity of calves than on that of hinds. Whereas no difference was found for hinds, calves of the low intake group showed mean immunoglobulin (Ig) levels higher than those on a standard diet, which suggests that Ig level may indicate the level of fighting against pathogens. Serum indices of body condition in calves showed generally positive correlations with milk nutrient production. In contrast, Ig level within each group showed a pattern inverse to that of the other group for early lactation: in the standard diet group, the greater the milk nutrient produced and calf growth, the lower the Ig level; this relationship was inversed in the low-nutrition group. These results suggest that, on a standard diet, high Ig levels may indicate high levels of pathogen fighting paired to poorer body condition. Inversely, once the first barriers of innate immunity are surpassed, only those calves on the low-nutrition group with greater resources would be able to spend more resources to fight infection. Thus, low calorie intake might boost its slowing effect on growth by increasing the costs of infection fighting.     

Mouse resistin modulates adipogenesis and glucose uptake in 3T3-L1 preadipocytes through the ROR1 receptor

Mouse resistin, a cysteine-rich protein primarily secreted from mature adipocytes, is involved in insulin resistance and type 2 diabetes. Human resistin, however, is mainly secreted by immune mononuclear cells, and it competes with lipopolysaccharide for the binding to Toll-like receptor 4, which could mediate some of the well-known proinflammatory effects of resistin in humans. In addition, resistin has been involved in the regulation of many cell differentiation and proliferation processes, suggesting that different receptors could be involved in mediating its numerous effects. Thus, a recent work identifies an isoform of Decorin (Δ Decorin) as a functional resistin receptor in adipocyte progenitors that may regulate white adipose tissue expansion. Our work shows that the mouse receptor tyrosine kinase-like orphan receptor (ROR)1 could mediate some of the described functions of resistin in 3T3-L1 adipogenesis and glucose uptake. We have demonstrated an interaction of mouse resistin with specific domains of the extracellular region of the ROR1 receptor. This interaction results in the inhibition of ROR1 phosphorylation, modulates ERK1/2 phosphorylation, and regulates suppressor of cytokine signaling 3, glucose transporter 4, and glucose transporter 1 expression. Moreover, mouse resistin modulates glucose uptake and promotes adipogenesis of 3T3-L1 cells through ROR1. In summary, our results identify mouse resistin as a potential inhibitory ligand for the receptor ROR1 and demonstrate, for the first time, that ROR1 plays an important role in adipogenesis and glucose homeostasis in 3T3-L1 cells. These data open a new line of research that could explain important questions about the resistin mechanism of action in adipogenesis and in the development of insulin resistance.     

RhoA signaling modulates cyclin D1 expression in human lung fibroblasts; implications for idiopathic pulmonary fibrosis

Background

To elucidate further the pathogenesis of sporadic, idiopathic pulmonary arterial hypertension (IPAH) and identify potential therapeutic avenues, differential gene expression in IPAH was examined by suppression subtractive hybridisation (SSH).

Methods

Peripheral lung samples were obtained immediately after removal from patients undergoing lung transplant for IPAH without familial disease, and control tissues consisted of similarly sampled pieces of donor lungs not utilised during transplantation. Pools of lung mRNA from IPAH cases containing plexiform lesions and normal donor lungs were used to generate the tester and driver cDNA libraries, respectively. A subtracted IPAH cDNA library was made by SSH. Clones isolated from this subtracted library were examined for up regulated expression in IPAH using dot blot arrays of positive colony PCR products using both pooled cDNA libraries as probes. Clones verified as being upregulated were sequenced. For two genes the increase in expression was verified by northern blotting and data analysed using Student's unpaired two-tailed t-test.

Results

We present preliminary findings concerning candidate genes upregulated in IPAH. Twenty-seven upregulated genes were identified out of 192 clones examined. Upregulation in individual cases of IPAH was shown by northern blot for tissue inhibitor of metalloproteinase-3 and decorin (P < 0.01) compared with the housekeeping gene glyceraldehydes-3-phosphate dehydrogenase.

Conclusion

Four of the up regulated genes, magic roundabout, hevin, thrombomodulin and sucrose non-fermenting protein-related kinase-1 are expressed specifically by endothelial cells and one, muscleblind-1, by muscle cells, suggesting that they may be associated with plexiform lesions and hypertrophic arterial wall remodelling, respectively.     

Discovery of inhibitors of Pseudomonas aeruginosa virulence through the search for natural-like compounds with a dual role as inducers and substrates of efflux pumps

Multidrug efflux pumps are ancient elements encoded in every genome, from bacteria to humans. In bacteria, in addition to antibiotics, efflux pumps extrude a wide range of substrates, including quorum sensing signals, bacterial metabolites, or plant-produced compounds. This indicates that their original functions may differ from their recently acquired role in the extrusion of antibiotics during human infection. Concerning plant-produced compounds, some of them are substrates and inducers of the same efflux pump, suggesting a coordinated plant/bacteria coevolution. Herein we analyse the ability of 1243 compounds from a Natural Product-Like library to induce the expression of P. aeruginosa mexCD-oprJ or mexAB-oprM efflux pumps' encoding genes. We further characterized natural-like compounds that do not trigger antibiotic resistance in P. aeruginosa and that act as virulence inhibitors, choosing those that were not only inducers but substrates of the same efflux pump. Four compounds impair swarming motility, exotoxin secretion through the Type 3 Secretion System (T3SS) and the ability to kill Caenorhabditis elegans, which might be explained by the downregulation of genes encoding flagellum and T3SS. Our results emphasize the possibility of discovering new anti-virulence drugs by screening natural or natural-like libraries for compounds that behave as both, inducers and substrates of efflux pumps.     

Ultrastructural changes in Cladosporium cucumerinum during pathogenesis.

Three ultrastructural patterns, each one associated with a different stage of pathogenesis, were observed in Cladosporium cucumerinum infecting cucumber cytoledons. (i) Fungal prepenetration structures (conidia and germ tubes) contained numberous lipid bodies. Microbodies were abundant and often associated with lipid bodies. Mitochondria were also abundant. (ii) During the invasion stage, no lipid bodies and relatively few microbodies were observed. Mitochondria were abundant, but differed markedly morphologically from those observed in the prepenetration structures. (iii) In the colonizing hyphae, microbodies were the most abundant organelle, lipid bodies were seldom found, and mitochondria were as observed during invasion. These changes in numbers of organelles may be associated with differences in the metabolic activities of the pathogen at various stages of pathogenesis.