Redox signals as a language of interorganellar communication in plant cells

Plants are redox systems and redox-active compounds control and regulate all aspects of their life. Recent studies have shown that changes in reactive oxygen species (ROS) concentration mediated by enzymatic and non-enzymatic antioxidants are transferred into redox signals used by plants to activate various physiological responses. An overview of the main antioxidants and redox signaling in plant cells is presented. In this review, the biological effects of ROS and related redox signals are discussed in the context of acclimation to changing environmental conditions. Special attention is paid to the role of thiol/disulfide exchange via thioredoxins (Trxs), glutaredoxins (Grxs) and peroxiredoxins (Prxs) in the redox regulatory network. In plants, chloroplasts and mitochondria occupying a chloroplasts and mitochondria play key roles in cellular metabolism as well as in redox regulation and signaling. The integrated redox functions of these organelles are discussed with emphasis on the importance of the chloroplast and mitochondrion to the nucleus retrograde signaling in acclimatory and stress response.     

What if we lose a hub? Experimental testing of pollination network resilience to removal of keystone floral resources

On the basis of theoretical predictions, pollination networks seem to be resilient to random node elimination but sensitive to targeted exclusion. However, such predictions have a very weak empirical basis. In order to test the robustness of the pollination network to short-term disturbances, we removed inflorescences of the most connected species occurring in a lowland meadow network using the before–after approach and compared the result with that obtained by network modelling. The manipulated network showed no significant differences for the most commonly used metrics, but was more generalized than control networks, owing to a change in the preferences of pollinators. Furthermore, no secondary extinctions (emigrations) were found, owing to the considerable natural variation found among insect species assemblages. Following elimination of the most linked plant species, a new hub was detected in the experimental meadow, the hub node being a plant species with a similar inflorescence to that removed, and formerly playing the role of a peripheral node. We conclude that exclusion of the main food source forced insects to change their specialized preferences to other plant species that were available. Mostly, these had inflorescences similar to those that were removed.     

The Relationships between Polymorphisms in Genes Encoding the Growth Factors TGF-β1, PDGFB,EGF, bFGF and VEGF-A and the Restenosis Process in Patients with Stable Coronary Artery Disease Treated with Bare Metal Stent

Background

Neointima forming after stent implantation consists of vascular smooth muscle cells (VSMCs) in 90%. Growth factors TGF-β1, PDGFB, EGF, bFGF and VEGF-A play an important role in VSMC proliferation and migration to the tunica intima after arterial wall injury. The aim of this paper was an analysis of functional polymorphisms in genes encoding TGF-β1, PDGFB, EGF, bFGF and VEGF-A in relation to in-stent restenosis (ISR).

Materials and Methods

265 patients with a stable coronary artery disease (SCAD) hospitalized in our center in the years 2007–2011 were included in the study. All patients underwent stent implantation at admission to the hospital and had another coronary angiography performed due to recurrence of the ailments or a positive result of the test assessing the coronary flow reserve. Angiographically significant ISR was defined as stenosis >50% in the stented coronary artery segment. The patients were divided into two groups–with angiographically significant ISR (n = 53) and without significant ISR (n = 212). Additionally, the assessment of late lumen loss (LLL) in vessel was performed. EGF rs4444903 polymorphism was genotyped using the PCR-RFLP method whilst rs1800470 (TGFB1), rs2285094 (PDGFB) rs308395 (bFGF) and rs699947 (VEGF-A) were determined using the TaqMan method.

Results

Angiographically significant ISR was significantly less frequently observed in the group of patients with the A/A genotype of rs1800470 polymorphism (TGFB1) versus patients with A/G and G/G genotypes. In the multivariable analysis, LLL was significantly lower in patients with the A/A genotype of rs1800470 (TGFB1) versus those with the A/G and G/G genotypes and higher in patients with the A/A genotype of the VEGF-A polymorphism versus the A/C and C/C genotypes. The C/C genotype of rs2285094 (PDGFB) was associated with greater LLL compared to C/T heterozygotes and T/T homozygotes.

Conclusions

The polymorphisms rs1800470, rs2285094 and rs6999447 of the TGFB1, PDGFB and VEGF-A genes, respectively, are associated with LLL in patients with SCAD treated by PCI with a metal stent implantation.     

Morphology engineering of basidiomycetes for improved laccase biosynthesis

Objective

This work is the first application of a morphological engineering technique called microparticle-enhanced cultivation (MPEC) aimed at the facilitation of laccase production in the submerged cultures by two basidiomycetes species Cerrena unicolor and Pleurotus sapidus.

Results

The positive effect of the applied 10 μm Al₂O₃ microparticles at concentrations from 5 to 30 g Al₂O₃ l^?1 was shown. Laccase activity increased 3.5-fold for C. unicolor and 2-fold for P. sapidus at 15 g Al₂O₃ l^?1 on 9 and 14 day of the cultivation, respectively, compared to the control culture without microparticles. The increase of laccase activity in the cultivation broths was caused by the action of Al₂O₃ microparticles on the agglomeration of hyphae. It led to the decrease of the size of the pellets, (on average by 2 mm for C. unicolor), the change of their shape (star-shaped pellets for C. unicolor) and the change of their structure (more compact pellets for P. sapidus).

Conclusions

Application of MPEC for the submerged cultures of two laccase-producing basidiomycetes proved successful in increasing of enzyme production.

     

Study of the Serum Copper Levels in Patients with Major Depressive Disorder

Copper may be involved in the pathophysiology of depression. Clinical data on this issue are very limited and not conclusive. The purpose of the study was to determine the copper concentration in the serum of patients with major depressive disorder and to discuss its potential clinical usefulness as a biomarker of the disease. A case–control clinical study included 69 patients with current depressive episode, 45 patients in remission and 50 healthy volunteers. Cu concentration was measured by electrothermal atomic absorption spectrometry (ETAAS). The mean serum copper level in depressed patients was slightly lower (by 11 %; not statistically significant) than in the control group. Furthermore, there was no significant difference in Cu²⁺ concentration between depressive episode and remission, nor between remission and control group. In the remission group were observed significant correlations between copper levels and the average number of relapses over the past years or time of remission. There was no correlation between serum copper and severity of depression, as measured by HDRS and MADRS. The obtained results showed no significant differences between the copper concentration in the blood serum of patients (both with current depressive episode and in remission) and healthy volunteers, as well as the lack of correlations between the copper level in the active stage of the disease and clinical features of the population. Our study is the first conducted on such a large population of patients, so the results may be particularly important and reliable source of knowledge about the potential role of copper in depression.     

Effect of extrusion on the nutritional value of peas for broiler chickens

The study was conducted to investigate the nutritional value of five samples of raw and extruded pea seeds (Pisum sativum L., Tarachalska cv.) from different experimental fields. The study included 150 male 1-day-old Ross 308 chickens, which were randomly assigned to three dietary treatments (50 replications each) and kept in individual cages. From days 1 to 16, all birds received only the basal diets. From days 17 to 21, the control group received still the basal diet, but for the two other groups, 20% of basal diet was replaced by raw or extruded peas. Furthermore, the groups receiving raw or extruded peas were divided into five subgroups of 10 animals each, where the diets contained one of the five pea samples of the same cultivar grown at different locations, respectively. On days 19 and 20, excreta were individually collected, and then all chickens were sacrificed and ileal digesta were sampled for determination of ileal digestibility, which was calculated by the difference method. Extrusion of pea seeds decreased the contents of crude fibre, acid and neutral detergent fibre, trypsin inhibitor activity (TIA), phytic P and resistant starch (RS) (p ≤ 0.05), but increased the contents of apparent metabolisable energy (AME_N) by approximately 2.25 MJ/kg dry matter (DM). Furthermore, extrusion improved the DM and crude protein digestibility significantly by about 21.3% and 11.6%, respectively. Similar results were observed for the digestibility of all analysed amino acids. In conclusion, extrusion markedly influenced the chemical composition of peas, reduced their contents of phytic P, TIA and RS and consequently had a positive impact on nutrient digestibility and AME_N values.     

Haloperidol,but not olanzapine,may affect expression of PER1 and CRY1 genes in human glioblastoma cell line

Background: There is barely any evidence of antipsychotic drugs affecting the molecular clockwork in human, yet it is suggested that clock genes are associated with dopaminergic transmission, i.e. the main target of this therapeutics. We decided to verify if haloperidol and olanzapine affect expression of CLOCK, BMAL1, PER1 and CRY1 in a human central nervous system cell line model. Methods: U-87MG human glioblastoma cell line was used as an experimental model. The cells were incubated with or without haloperidol and olanzapine in the concentration of 5 and 20 μM for 24 h. Real-time quantitative polymerase chain reaction with the ΔC_T analysis was used to examine the effect of haloperidol and olanzapine on the mRNA expression of the genes. Results: At 5 μM, haloperidol decreased expression of CRY1 almost 20-fold. There was nearly a 1.5-fold increase in expression of PER1. Considering the 20 μM haloperidol concentration and both olanzapine concentrations, no other statistically significant effect was observed. Conclusions: At certain concentration, haloperidol seems to affect expression of particular clock genes in a human central nervous system cell line model, yet mechanism underlying this phenomenon remains elusive.     

Catechol-oxide-methyltransferase (<Emphasis Type="Italic">COMT</Emphasis> rs4680:G&gt;A) gene polymorphism does not affect analgesics’ demand after elective hip replacement

Pain in patients with hip osteoarthritis appears long before surgery, and requires effective management as it affects patient comfort and daily activities. Therefore, the search for factors influencing response rate to analgesics is mandatory. In recent years, increasing attention has been paid to genetic factors underlying pain threshold and treatment efficacy. Polymorphic gene of catechol-oxide-methyltransferase (COMT) is a candidate gene associated with pain pathology and treatment response. The aim of the study was to evaluate association between the COMT rs4680:G>A polymorphism and demand for analgesics in patients subjected to elective hip replacement. The study included 196 patients after hip replacement surgery. Opioid demand was recorded and analgesic efficacy was scored using a four-level verbal pain intensity scale. COMT rs4680:G>A polymorphism was analysed by PCR-RFLP method. The studied COMT genotypes did not influence opioid administration in the studied patients from the day of surgery till day 6 afterwards. The distribution of the COMT rs4680:G>A in the studied subjects was as follows: GA—52.04%, AA—23.98% and GG—23.98%. It can be concluded that the COMT rs4680:G>A polymorphism is not associated with opioid demand in patients after elective hip replacement.