CD4 T cells producing pro-inflammatory interleukin-17 mediate high pathology in schistosomiasis

In murine schistosomiasis mansoni, pronounced CD4 T cell-mediated, egg-induced, hepato-intestinal immunopathology and death, whether genetically determined or elicited experimentally, are associated with failure to down-regulate a net pro-inflammatory immune response. Important evidence contributing to this notion comes from the observation that immunization with schistosome egg antigens in CFA (SEA/CFA) causes low pathology C57BL/6 mice to develop an exacerbated form of disease and death in a cytokine milieu characterized by elevated interferon (IFN)-gamma levels. Since such a pro-inflammatory environment presumes a signaling pathway involving interleukin (IL)-12, the SEA/CFA immunization model was used to examine the extent of hepatic immunopathology in the absence of this cytokine. Surprisingly, the IL-12p40 subunit was an absolute requirement for the development of exacerbated disease, whereas the IL-12p35 subunit was not. Moreover, significantly elevated in vitro production of IL-17, but not of IFN-gamma, correlated with the high pathology, and neutralization of IL-17 in vivo resulted in a significant reduction of hepatic inflammation. Our findings clearly demonstrate the pathogenic potential of the novel IL-17-producing T cell subpopulation (ThIL-17), previously shown to mediate chronic inflammation in autoimmune disease. They also imply that IL-23, but not IL-12, is the critical signal necessary to support the pro-inflammatory ThIL-17 subset involved in high pathology schistosomiasis.     

Conformational features of the Dippu-AST 8 neuropeptide from the cockroach Diploptera punctata

Spatial structure and conformational properties of the Dippu-AST 8 (allatostatin III) neuropeptide have been investigated by the molecular mechanics method. The conformational energy and geometrical parameters corresponding to the low-energy states of the molecule are obtained. A single backbone conformation with a very restricted set of Ser 3, Phe 4 and Leu 9 amino acids positions is observed for Dippu-AST 8 neuropeptide.     

Antigen sensitization modulates alveolar macrophage functions in an asthma model

Fibroblast/myofibroblast expansion is critical in the pathogenesis of pulmonary fibrosis. To date, most research has focused on profibrotic mediators, whereas studies on antifibrotic factors are scanty. In this study, we explored the effects of acidic fibroblast growth factor (FGF-1) and FGF-1 plus heparin (FGF-1+H) on fibroblast growth rate, apoptosis, and myofibroblast differentiation. Heparin was used because it participates in FGF-1 signaling. Growth rate was evaluated by WST-1 colorimetric assay, DNA synthesis by [(3)H]thymidine incorporation, and apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and cleaved caspase 3. Expression of alpha-smooth muscle actin (alpha-SMA) was examined by immunocytochemistry, flow cytometry, real-time PCR, and immunoblotting. Despite the induction of DNA synthesis, FGF-1+H significantly reduced fibroblast growth rate. This correlated with a significant increase in apoptosis, evaluated by TUNEL (41.6 +/- 1.4% vs. 12.5 +/- 0.6% from controls; P < 0.01) and cleaved caspase 3 (295 +/- 32 vs. 200 +/- 19 ng/10(6) cells from controls; P < 0.05). Double immunostaining (alpha-SMA-TUNEL) revealed that the levels of induced apoptosis were similar in fibroblasts and myofibroblasts. FGF-1+H inhibited the effect of TGF-beta1 on myofibroblast differentiation. alpha-SMA-positive cells were reduced by immunocytochemistry from 44.5 +/- 6.5% to 10.9 +/- 1.9% and by flow cytometry from 30.6 +/- 2.5% to 7.7 +/- 0.6% (P < 0.01). Also, FGF-1+H significantly inhibited the TGF-beta1 induction of alpha-SMA quantified by real-time PCR and Western blot. This decrease was associated with a 35% reduction in TGF-beta1-induced collagen gel contraction. The effect of FGF-1+H was mediated by a significant decrease of TGF-beta1-induced Smad2 phosphorylation. FGF-1 alone exhibited similar but lower effects. These findings suggest that FGF-1 can have an antifibrogenic role, inducing apoptosis of fibroblasts and inhibiting myofibroblast differentiation.     

Archaeal diversity in two thermophilic chalcopyrite bioleaching reactors

This study used a culture-independent molecular approach to investigate the archaeal community composition of thermophilic bioleaching reactors. Two culture samples, MTC-A and MTC-B, grown with different concentrations of chalcopyrite (CuFeS₂), a copper sulfidic ore, at a temperature of 78°C and pH 1.6 were studied. Phylogenetic analysis of the 16S rRNA genes revealed that both cultures consisted of Archaea belonging to the Sulfolobales . The 16S rRNA gene clone library of MTC-A grown with 4% (w/v) chalcopyrite was dominated by a unique phylotype related to Sulfolobus shibatae (69% of total clones). The remaining clones were affiliated with Stygiolobus azoricus (11%), Metallosphaera sp. J1 (8%), Acidianus infernus (2%), and a novel phylotype related to Sulfurisphaera ohwakuensis (10%). In contrast, the clones from MTC-B grown with 12% (w/v) chalcopyrite did not appear to contain Sulfolobus shibatae -like organisms. Instead the bioleaching consortium was dominated by clones related to Sulfurisphaera ohwakuensis (73.9% of total clones). The remaining microorganisms detected were similar to those found in MTC-A.     

Pseudophosphorylation of tau at serine 422 inhibits caspase cleavage: in vitro evidence and implications for tangle formation in vivo

The tangles of Alzheimer's disease (AD) are comprised of the tau protein displaying numerous alterations, including phosphorylation at serine 422 (S422) and truncation at aspartic acid 421 (D421). Truncation at the latter site appears to result from activation of caspases, a class of proteases that cleave specifically at aspartic acid residues. It has been proposed that phosphorylation at or near caspase cleavage sites could regulate the ability of the protease to cleave at those sites. Here, we use tau pseudophosphorylated at S422 (S422E) to examine the effects of tau phosphorylation on its cleavage by caspase 3. We find that S422E tau is more resistant to proteolysis by caspase 3 than non-pseudophosphorylated tau. Additionally, we use antibodies directed against the phosphorylation site and against the truncation epitope to assess the presence of these epitopes in neurofibrillary tangles in the aged human brain. We show that phosphorylation precedes truncation during tangle maturation. Moreover, the distribution of the two epitopes suggests that a significant length of time (perhaps as much as two decades) elapses between S422 phosphorylation and cleavage at D421. We further conclude that tau phosphorylation at S422 may be a protective mechanism that inhibits cleavage in vivo.     

The effect of root pressurization on water relations, shoot growth, and leaf gas exchange of peach (Prunus persica) trees on rootstocks with differing growth potential and hydraulic conductance

It is well known that rootstocks can have an effect on the vegetative growth and development of the tree; however, there has been no clear explanation about the physiological mechanism involved in this phenomenon. Evidence indicates that the rootstock effects on tree vegetative growth may be related to hydraulic limitations of the rootstock. The objective of these experiments was to investigate the shoot growth, water potential, and gas exchange of peach trees on different rootstocks in response to manipulations of water relations of trees on rootstocks that differ in root hydraulic conductance. Tree water relations were manipulated by applying different amounts of pneumatic pressure on the root system and then relative shoot extension growth rate, tree transpiration rate, leaf water potential, leaf conductance, leaf transpiration, and net CO(2) exchange rate responses were measured. Root pressurization increased leaf water potential, relative shoot extension growth rate, leaf conductance, leaf transpiration, and net CO(2) exchange rates of trees on both vigorous and dwarfing rootstocks. There was a significant positive linear correlation between applied pneumatic pressure and tree transpiration rate and leaf water potential. Leaf conductance, transpiration rate, and net CO(2) exchange rate as well as relative shoot extension growth rates were also positively correlated with the applied pneumatic pressure on the root system. These relationships were consistent across both vigorous and size-controlling rootstocks, indicating that rootstock hydraulic limitation may be directly involved in the vegetative growth control of peach trees.     

Identification of AGR2 protein, a novel potential cancer marker, using proteomics technologies

A comparative analysis of the proteins in prostate tissues of the patients operated for hyperplasia (n = 7) or cancer (n = 5) was performed aiming to search for protein diagnostic markers. Differences in several minor proteins were detected using two-dimensional electrophoresis according to O'Farrel; among them, an additional protein with a molecular weight of 19 kDa and an isoelectric point of 9.0 was observed in four of the cancer cases. Mass spectrometry allowed this protein to be identified as the androgen-induced secreted protein AGR2. The possibility of using AGR2 as a diagnostic marker of prostate cancer is discussed.     

Somatic mutagenesis at T-cell receptor locus in inhabitants of radiation polluted regions as a result of the Chernobyl disaster

In the period of 2001-2004, frequency of cells bearing mutations at T-cell receptor (TCR) locus was assessed in 553 inhabitants of radiation polluted regions of the Russian Federation and 154 unexposed control persons. The inhabitants were divided into three groups according to age at the moment of the Chernobyl disaster and 137Cs pollution density: 1) in utero, 37-555 kBq/m2; 2) 0-14 years old, 20-555 kBq/m2; 3) 18 and more years old, highest 137Cs density (185 more than 555 kBq/m2). The most intense changes of the TCR-mutant cell frequency were observed in the group of persons exposed to ionizing radiation in utero. The mean frequency of the mutant cells was higher in the first group than in age-matched control group by about 1.5-fold: 4.0 x 10(-4) vs 2.7 x 10(-4) accordingly (p < 0.0001). Elevation in the mean TCR-mutant cell frequency was less expressed in group of inhabitants aged 0-14 years at the moment of irradiation start: 1.3-fold increase in comparison to age-matched control (3.8 x 10(-4) vs 2.9 x 10(-4), p = 0.0002). It was not found significant differences in mutant cell frequencies between control group and adults consisting in the third group (18 and more years old at the moment of the Chernobyl accident). The changes of the TCR-mutant cell frequency in persons exposed in pre- and postnatal periods differ not only quantitatively, but qualitatively. In the fist case all persons react to irradiation by increasing number of the TCR-mutant cells in some degree. In the second case - only a part of population. Proportion of reacting persons depends on age at the start of irradiation and, perhaps, on dose absorbed. The TCR-mutant frequency was significantly higher in persons with benign tumors of different localizations and nodules in thyroid gland than in persons without this pathology.     

Sex characteristics of neuroendocrine effects of prenatal exposure to exogenous glucocorticoids

The effects of hydrocortisone acetate treatment of rats during the last gestational week on neurochemical and morphological characteristics of the brain in early postnatal and mature offspring were studied. Disappearance of sexual differences both in aromatase and 5alpha-reductase activities and noradrenaline concentration in the preoptic area in 10-day old rats was found. Meanwhile a sexual dimorphism in serotonin metabolism emerged. In adult offspring, the prenatal exposure to glucocorticoids resulted in disappearance of sexual differences in neurocytes' nuclei volume in medial preoptic and suprachiasmatic nuclei. The adrenocortical reaction to noradrenaline infusion to the 3rd brain ventricle was absent in the experimental males and intensified in females. In males, adrenocortical reaction to restraint decreased while post-stress changes in hypothalamic noradrenaline concentration and hippocampal glutamate decarboxylase activity were not observed. In the similar experiments in females both the augmentation of adrenocortical reaction and inhibition of GABA-ergic system were revealed. The results obtained indicate the modifying effect of prenatal exposure to glucocorticoids on sexual dimorphism of neuroendocrine system.