Expression of glucocorticoid receptor in the intestine of a euryhaline teleost, the Mozambique tilapia (Oreochromis mossambicus): effect of seawater exposure and cortisol treatment

Cortisol plays an important role in controlling intestinal water and ion transport in teleosts possibly through glucocorticoid receptor (GR) and/or mineralocorticoid receptor. To better understand the role of GR in the teleost intestine, in a euryhaline tilapia, Oreochromis mossambicus, we examined (1) the intestinal localizations of GR; (2) the effects of environmental salinity challenge and cortisol treatment on GR mRNA expression. The mRNA abundance of GR in the posterior intestinal region of tilapia was found to be higher than that in the anterior and middle intestine. In the posterior intestine, GR appears to be localized in the mucosal layer. GR mRNA levels in the posterior intestine were elevated after exposure of freshwater fish to seawater for 7 days following an increase in plasma cortisol. Similarly, cortisol implantation in freshwater tilapia for 7 days elevated the intestinal GR mRNA. These results indicate that seawater acclimation is accompanied by upregulation of GR mRNA abundance in intestinal tissue, possibly as a consequence of the elevation of cortisol levels. In contrast, a single intraperitoneal injection of cortisol into freshwater tilapia decreased intestinal GR mRNA. This downregulation of the GR mRNA by cortisol suggests a dual mode of autoregulation of GR expression by cortisol.     

Assessment of salt tolerance in Populus alba clones using chlorophyll fluorescence

Cuttings of five Populus alba clones (S18 F1-26, Al29 F8-35, J3 F1-4, GU1 F16-36, PO9 F21-88), Populus euphratica, and Populus×euramericana (I-214) were submitted during 45 d to regular watering with NaCl solutions of electrical conductivity of 7 and 14 dS m⁻¹. Chlorophyll a fluorescence in response to the salinity stress was assessed, using F₀ and F_v/F_m. Differences in reaction to the salt were found in P. alba clones, F₀ and F_v/F_m being the fluorescence parameters used to check out this stress. Minimal constant fluorescence of dark-adapted plants (F₀) showed a better correlation with the disease index exhibited by plants and also with salinity dose than the parameter F_v/F_m. Some of the P. alba clones showed the same behaviour, assessed through fluorescence parameters, as P. euphratica, which was previously defined as salt tolerant, while the rest exhibited the same characteristics as I-214, which was very sensitive.     

Spinal afferent neurons projecting to the rat lung and pleura express acid sensitive channels

The molecular mechanisms of Idiopathic Pulmonary Fibrosis (IPF) remain elusive. Transforming Growth Factor beta 1(TGF-β1) is a key effector cytokine in the development of lung fibrosis. We used microarray and computational biology strategies to identify genes whose expression is significantly altered in alveolar epithelial cells (A549) in response to TGF-β1, IL-4 and IL-13 and Epstein Barr virus. A549 cells were exposed to 10 ng/ml TGF-β1, IL-4 and IL-13 at serial time points. Total RNA was used for hybridisation to Affymetrix Human Genome U133A microarrays. Each in vitro time-point was studied in duplicate and an average RMA value computed. Expression data for each time point was compared to control and a signal log ratio of 0.6 or greater taken to identify significant differential regulation. Using normalised RMA values and unsupervised Average Linkage Hierarchical Cluster Analysis, a list of 312 extracellular matrix (ECM) proteins or modulators of matrix turnover was curated via Onto-Compare and Gene-Ontology (GO) databases for baited cluster analysis of ECM associated genes. Interrogation of the dataset using ontological classification focused cluster analysis revealed coordinate differential expression of a large cohort of extracellular matrix associated genes. Of this grouping members of the ADAM (A disintegrin and Metalloproteinase domain containing) family of genes were differentially expressed. ADAM gene expression was also identified in EBV infected A549 cells as well as IL-13 and IL-4 stimulated cells. We probed pathologenomic activities (activation and functional activity) of ADAM19 and ADAMTS9 using siRNA and collagen assays. Knockdown of these genes resulted in diminished production of collagen in A549 cells exposed to TGF-β1, suggesting a potential role for these molecules in ECM accumulation in IPF.     

Quantitative trait loci for resistance to Sclerotinia sclerotiorum and its association with a homeologous non-reciprocal transposition in Brassica napus L.

Sclerotinia stem rot, caused by fungus Sclerotinia sclerotiorum, is one of the most devastating diseases in rapeseed (Brassica napus L.). We report the identification of Quantitative trait loci (QTL) involved in the resistance to S. sclerotiorum in two segregating populations of DH lines: the HUA population, derived from a cross between a partially resistant Chinese winter line (Hua dbl2) and a susceptible European spring line (P1804); and the MS population, derived from a partially resistant French winter cultivar (Major) and a susceptible Canadian spring cultivar (Stellar). A petiole inoculation technique and two scoring methods, days to wilt (DW) and stem lesion length (SLL), were used for the resistance assessment. A total of eight genomic regions affecting resistance were detected in the HUA population, with four of these regions affecting both measures of resistance. Only one region, which affected both measurements, was detected in the MS population. Individual QTL explained 6–22% of the variance. At five of the QTL from both populations, alleles from the resistant parent contributed to the resistance. QTL on N2 from the HUA population had the highest LOD score and R ² value and was detected for SLL in the first evaluation. The N12 resistance allele in Hua dbl2 was detected in a region containing a homeologous non-reciprocal transposition (HNRT) from the resistance-containing portion of N2. This result suggests that QTL in the N12.N2 HNRT enhanced the resistance of Hua dbl2 by increasing the dosage of resistance genes. The relationship of QTL from different genetic backgrounds and their associations with other agronomic traits are discussed.     

Plasmodium falciparum Adhesion on Human Brain Microvascular Endothelial Cells Involves Transmigration-Like Cup Formation and Induces Opening of Intercellular Junctions

Cerebral malaria, a major cause of death during malaria infection, is characterised by the sequestration of infected red blood cells (IRBC) in brain microvessels. Most of the molecules implicated in the adhesion of IRBC on endothelial cells (EC) are already described; however, the structure of the IRBC/EC junction and the impact of this adhesion on the EC are poorly understood. We analysed this interaction using human brain microvascular EC monolayers co-cultured with IRBC. Our study demonstrates the transfer of material from the IRBC to the brain EC plasma membrane in a trogocytosis-like process, followed by a TNF-enhanced IRBC engulfing process. Upon IRBC/EC binding, parasite antigens are transferred to early endosomes in the EC, in a cytoskeleton-dependent process. This is associated with the opening of the intercellular junctions. The transfer of IRBC antigens can thus transform EC into a target for the immune response and contribute to the profound EC alterations, including peri-vascular oedema, associated with cerebral malaria.     

Identification and biochemical characterization of the novel mutation m.8839G>C in the mitochondrial ATP6 gene associated with NARP syndrome

Mutations in the ATP6 gene are reported to be associated with Leber hereditary optic neuropathy, bilateral striatal necrosis, coronary atherosclerosis risk and neuropathy, ataxia and retinitis pigmentosa (NARP)/maternally inherited Leigh syndromes. Here, we present a patient with NARP syndrome, in whom a previously undescribed mutation was detected in the ATP6 gene: m.8839G>C. Several observations support the concept that m.8839G>C is pathogenically involved in the clinical phenotype of this patient: (1) the mutation was heteroplasmic in muscle; (2) mutation load was higher in the symptomatic patient than in the asymptomatic carriers; (3) cybrids carrying this mutation presented lower cell proliferation, increased mitochondrial DNA (mtDNA) copy number, increased steady‐state OxPhos protein levels and decreased mitochondrial membrane potential with respect to isogenic wild‐type cybrids; (4) this change was not observed in 2959 human mtDNAs from different mitochondrial haplogroups; (5) the affected amino acid was conserved in all the ATP6 sequences analyzed; and (6) using in silico prediction, the mutation was classified as ‘probably damaging’. However, measurement of ATP synthesis showed no differences between wild‐type and mutated cybrids. Thus, we suggest that m.8839G>C may lower the efficiency between proton translocation within F₀ and F₁ rotation, required for ATP synthesis. Further experiments are needed to fully characterize the molecular mechanisms involved in m.8839G>C pathogenicity .     

Parietaria pollen a new aeroallergen in the city of Valparaiso, Chile

Parietaria pollen has never been considered as a significant cause of pollinosis in Chile; therefore, the sensitization to Parietaria study has never been included in the study of patients with clinical suspicion of pollinosis in this region. The objective of this study was to describe the clinical characteristics of pollinosis caused by Parietaria in the Valparaíso region, related to air concentrations of this kind of pollen. A cross-sectional study was performed in the city of Valparaíso. It consisted of two stages: In the first, pollen grains were counted between 1999 and 2001. In the second, a sensitization profile on a patient population diagnosed with ARC (allergic rhinoconjunctivitis) was evaluated. Parietaria judaica (P. judiaca) presented pollination all year long, with aggravation in the spring and summer, and with values reaching 80 grains/m³ (weekly average). These findings determined the transience of the symptoms in this population, which is mainly perennial with seasonal aggravations. A total of 72 atopic subjects were obtained during the whole sample recollection period. P. judaica was the second most frequent cause of sensitization (60 %) after Dermatophagoides in the sample overall. Also, in monosensitized subjects, it was the first cause of pollen sensitization. P. judaica represents the second cause of allergy in Valparaíso and the first cause of pollinosis. These findings suggest the importance of quantifying Parietaria in Valparaíso and near cities, plus investigating the presence of sensitization and symptoms to allergies in a significant proportion of patients in this region.     

Urinary iodine and thyroid function in a population of healthy pregnant women in the North of Spain

BackgroundIodine is an essential trace element for the synthesis of thyroid hormones, which are keys in maternal metabolism during pregnancy as well as in neurological development during fetal and postnatal life. This was a prospective study on iodine status and thyroid function in women during pregnancy in the Basque country to assess whether there was any relationship among maternal urinary iodine, maternal thyroid function and thyrotropin (TSH) in newborns, and to explore any difference in women experiencing miscarriages.MethodsWe analyzed TSH, free T₄ (FT₄), free T₃ (FT₃), thyroid peroxidase antibody (TPO-Ab) titers in serum and urinary iodine concentrations (UIC) in 2104 women in the first trimester of pregnancy and in 1322 of them in their second trimester. We obtained neonatal TSH levels in 1868 cases.ResultsIn the first (T1) and second trimesters (T2), the median UICs were 88.5 μg/L and 140 μg/L, respectively. No relationship was found between UIC and FT₄, or maternal and neonatal TSH. In T1 and T2, 9.7% and 7.5% of women were TPO-Ab positive, respectively. The total miscarriage rate was 10%. The percentage of miscarriages in healthy women was 8.9%, lower than in women with overt hypothyroidism (21.2%; p < 0.001) and than in women with subclinical hypothyroidism (15.6%; p < 0.025). The miscarriage rate was not higher in TPO-Ab-positive women.ConclusionsIn this study most women had iodine deficiency during pregnancy. Neonatal TSH is not correlated with maternal UIC during pregnancy. Pregnant women with hypothyroidism have a higher rate of miscarriages.