Benzo[a]pyrene and cyclopenta[c]phenanthrene suppress expression of p53 in head kidney of rainbow trout

Although p53, a protein of important tumor suppressive function, has been extensively studied in mammals, relatively little is known about the p53 pathways in lower vertebrates. Particularly, limited information exists on possible influences of environmental contaminants on the expression of the p53 gene in fish. In the current study, we assessed the effects of benzo[a]pyrene (B[a]P; potent tumor promoter) and cyclopenta[c]phenanthrene (CP[c]Ph; clastogenic agent) exposure on a 24h profile of p53 gene expression in head kidney of juvenile rainbow trout (Oncorhynchus mykiss). To analyze the p53 transcription rate, we developed protocol for the examination of both mRNA and heterogeneous nuclear (hn) RNA of the gene, using Real-Time RTPCR approach. The results show that both compounds are capable of suppressing p53 transcriptional activity within 12h of the treatment. Our finding supports the idea that structurally different PAHs may influence cell physiologic functions controlled by p53 in fish, in part, by down-regulating its RNA expression levels

Cyclopenta[c]phenanthrene induction of CYP1A in brain of rainbow trout (Oncorhynchus mykiss)

We assessed the effects of cyclopenta[c]phenanthrene (CP[c]Ph) and benzo[a]pyrene (B[a]P; positive control) on CYP1A gene expression in brain of juvenile rainbow trout (Oncorhynchus mykiss) using the quantitative reverse transcription polymerase chain reaction (Q-RT-PCR). A group of hatchery raised rainbow trout, with an average body mass of 49.4 g and total length of 15.5 cm were given an intraperitoneal injection (10 mg*kg-1) of either CP[c]Ph or B[a]P in corn oil (2 mg*mi-1 corn oil) or corn oil alone (control). After 24 and 48 h, trout brains were collected for mRNA isolation and analysis. After 24 hours of the exposure, only B[a]P-treated rainbow trout had 10-fold higher number of CYP1A transcripts (mean = 3.63*106 transcripts*µg-1 total RNA) than control fish (3.24*105 transcripts*µg-1 total RNA; Tukey test, P<0.05). After 48 hrs, significantly higher levels of CYP1A expression (Tukey test, P<0.001) were found in either CP[c]Ph- or B[a]P- induced group (1.45*106 and 6.92*106 transcriptsźµg-1 total RNA, respectively) over a control group (mean=1.41*105 transcripts*µg-1 total RNA). The finding that CYP1A in brain tissue was inducible by CP[c]Ph, a polycyclic aromatic hydrocarbon (PAH) of different than B[a]P planar characteristics, may further validate the use of rainbow trout brain CYP1A mRNA levels as a biomarker of PAH exposure

Preliminary study on adverse effects of phenanthrene and its methyl and phenyl derivatives in larval zebrafish, Danio rerio

Toxic effects of polycyclic aromatic hydrocarbons (PAHs) have been extensively studied in fish, although knowledge concerning biological activities of phenanthrene and its derivatives remains still incomplete. The aim of this work was to evaluate lethal and sublethal effects of benzo(a)pyrene, phenanthrene and phenanthrene derivatives (1-methylphenanthrene, 4-methylphenanthrene, 1-phenylphenanthrene and 4-phenylphenanthrene) on zebrafish (Danio rerio) larvae. We conducted acute toxicity test, using 96h static renewal exposure to a series of the PAH concentrations (0.05, 0.50, 5.00, 50.00µmol*l-1), to determine the No Effect Concentration (NEC) value for each compound examined. The mean NEC estimates obtained in the study were 5.16۪.45µmol*l-1 (B[a]P), 4.88۪.13µmol*l-1 (Ph), 40.24䔰.93µmol*l-1 (1P-Ph), 47.92ۭ.61µmol*l-1 (1M-Ph), 24.31۱.33µmol*l-1 (4P-Ph) and 3.11۫.01µmol*l-1 (4M-Ph) and suggested the following order of PAH toxicities on Danio rerio larvae: 4M-Ph>Ph˜B[a]P>4PPhP-Ph>1M-Ph. To gain insight into possible molecular mechanisms of apparent toxicity of phenanthrene derivatives on zebrafish larvae, we examined mRNA expression of cyp1a, cyp1b1, and vtg genes in the larvae exposed for 48h to a PAH concentration of 0.50µmol*l-1. Whereas the larvae exposed to each tested PAH displayed many developmental abnormalities (i.e. pericardial and yolk sac edema, dorsal curvature, or tail malformations), no significant upregulation of cyp1a and cyp1b1 mRNA was observed, except for zebrafish exposed to B[a]P. However, significant reduction of vtg mRNA was observed in the larvae exposed to phenanthrene and its 4P- derivative. The results may contribute to the development of a new knowledge about effects of structurally diverse phenanthrene derivatives on vertebrate organisms

MicroRNA expression profiles in liver and colon of sexually immature gilts after exposure to Fusarium mycotoxins

To improve our knowledge of the role of microRNAs (miRs) in responses of the porcine digestive system to two Fusarium mycotoxins, zearalenone (ZEN) and deoxynivalenol (DON), we examined the expression of 7 miRs (miR-9, miR-15a, miR-21, miR-34a, miR-122, miR-125b, and miR-192), previously found to be deregulated in diseased liver and colon cells. In this study, immature gilts were exposed to NOEL doses of ZEN (40 μg/kg/d), DON (12 μg/kg/d), ZEN+DON (40+12 μg/kg/d), and placebo (negative control group) for 7, 14, 21, 28, 35, and 42 days. Before the treatment, expression levels of the selected miRs were measured in the liver, the duodenum, the jejunum, and the ascending and the descending colon of the gilts. Hierarchical clustering of the tissues by their miR expression profiles was consistent with what would be expected based on the anatomical locations and the physiological functions of the organs, suggesting that functions of the miRs are related to the specificities of the tissues in which they are expressed. A subset of 2 pairs of miRs (miR-21+miR-192 and miR-15a+miR-34a), which were assigned to two distinct clusters based on their tissue abundance, was then evaluated in the liver and the ascending and the descending colon during the treatment. The most meaningful results were obtained from the ascending colon, where a significant effect of the treatment was observed, suggesting that during the exposure to mycotoxins, the pathways involved in cell proliferation and survival were disordered. Changes in miR expression in the liver and the descending colon of the treated gilts were smaller, and were associated more with treatment duration than the exposure to ZEN, DON, or ZEN+DON. Further research should focus on identification of genes whose expression is regulated by these aberrantly expressed miRs. This should facilitate understanding of the miRNA-regulated biological effects of mycotoxins

Is callose a barrier for lead ions entering Lemna minor L. root cells?

Plants have developed a range of strategies for resisting environmental stresses. One of the most common is the synthesis and deposition of callose, which functions as a barrier against stress factor penetration. The aim of our study was to examine whether callose forms an efficient barrier against Pb penetration in the roots of Lemna minor L. exposed to this metal. The obtained results showed that Pb induced callose synthesis in L. minor roots, but it was not deposited regularly in all tissues and cells. Callose occurred mainly in the protoderm and in the centre of the root tip (procambial central cylinder). Moreover, continuous callose bands, which could form an efficient barrier for Pb penetration, were formed only in the newly formed and anticlinal cell walls (CWs); while in other CWs, callose formed only small clusters or incomplete bands. Such an arrangement of callose within root CWs inefficiently protected the protoplast from Pb penetration. As a result, Pb was commonly present inside the root cells. In the light of the results, the barrier role of callose against metal ion penetration appears to be less obvious than previously believed. It was indicated that induction of callose synthesis is not enough for a successful blockade of the stress factor penetration. Furthermore, it would appear that the pattern of callose distribution has an important role in this defence strategy

The influence of plastic deformation and chemical environment on the resistively of al-alloy overhead lines

The electrical resistively and intensity of X-ray diffraction reflexes were determined for overhead line wires deformed plastically and immersed at different solutions. Immersing (chemical ageing) was performed by plastic deformation along the wire axis. During chemical ageing the samples were exposed to the action of the Cl-, SO4 2-, and SO3 2- ions. Resistively was measured at room temperature and at liquid nitrogen temperature. After the X-ray and resistively measurement data were compared, it was found that three processes could take place: the flow of ions through the boundary between a sample and environment; the mechanical relaxation of vacancies near a line of dislocations, and the ordering of microstructure. These effects can lead to the anisotropy of resistively

Present and prospective leather industry waste disposal

In this paper general characteristics of the main leather industry waste regarding its amount reduction by thermal treatment have been presented. Both the tannery solid wastes and the sludge contain organic substances. Their energy value is more than 50% higher in comparison to hard coal (nominally 20 MJ/kg as dry material). Up to now, the considerable amounts of energy are not recovered; leather wastes are predominantly on landfill. Implementation of a comprehensive thermal method for tannery solid waste and sludge utilization can permit to solve the waste disposal problem by effective neutralization of all of the waste. Moreover, it should bring economic benefits associated with steam or hot water production and landfill tax avoiding. The study is oriented towards the practical application

The process of waste incineration in the tanning industry

W artykule przedstawiono koncepcję unieszkodliwiania odpadów przemysłu garbarskiego poprzez spalanie w specjalnie do tego celu zaprojektowanej instalacji technologicznej. Proces ten przewiduje całościowe rozwiązanie problemu odpadów w garbarniach, niosąc również korzyści związane z odzyskiwaniem energii cieplnej, którą będzie można używać do procesów produkcyjnych. Podano również charakterystykę odpadów przemysłu garbarskiego w aspekcie ich spalania oraz wyniki badań laboratoryjnych i ćwierćtechnicznych, przeprowadzonych na Wydziale Inżynierii i Technologii Chemicznej Politechniki Krakowskiej.The article describes the conception of tannery waste treatment by combustion process in the specially designed system. The technology should provide tanneries with comprehensive solution for tannery waste problems. The additional advantage of the technology is the possibility to reuse energy from waste in tanning processes. Moreover, the characteristics of tannery waste in respect of its combustion as well as results of research carried out at the Faculty of Chemical Engineering and Technology are presented