Fühner-Wieland's Sammlung von Vergiftungsfällen

We have reported recently that the proliferation of PC12 cells exposed to micromolar concentrations of Tl(I) or Tl(III) has different outcomes, depending on the absence (EGF− cells) or the presence (EGF+ cells) of epidermal growth factor (EGF) added to the media. In the current work, we investigated whether EGF supplementation could also modulate the extent of Tl(I)- or Tl(III)-induced cell apoptosis. Tl(I) and Tl(III) (25–100 μM) decreased cell viability in EGF− but not in EGF+ cells. In EGF− cells, Tl(I) decreased mitochondrial potential, enhanced H2O2 generation, and activated mitochondrial-dependent apoptosis. In addition, Tl(III) increased nitric oxide production and caused a misbalance between the anti- and pro-apoptotic members of Bcl-2 family. Tl(I) increased ERK1/2, JNK, p38, and p53 phosphorylation in EGF− cells. In these cells, Tl(III) did not affect ERK1/2 and JNK phosphorylation but increased p53 phosphorylation that was related to the promotion of cell senescence. In addition, this cation significantly activated p38 in both EGF− and EGF+ cells. The specific inhibition of ERK1/2, JNK, p38, or p53 abolished Tl(I)-mediated EGF− cell apoptosis. Only when p38 activity was inhibited, Tl(III)-mediated apoptosis was prevented in EGF− and EGF+ cells. Together, current results indicate that EGF partially prevents the noxious effects of Tl by preventing the sustained activation of MAPKs signaling cascade that lead cells to apoptosis and point to p38 as a key mediator of Tl(III)-induced PC12 cell apoptosis.

Alzheimer’s disease (AD) is a multifactorial neurodegenerative disorder, characterized by the formation, aggregation and accumulation of amyloid beta, perturbed metal (copper, iron and zinc) homeostasis, metal-induced oxidative stress, neuroinflammation, aberrant activity of acetylcholinesterase (AChE) and other pathologies. The aim of this review is to discuss the current therapies based on the “combination-drugs-multitargets” strategy to target multiple pathologies to block the progression of pathogenesis of AD. In addition to cholinergic and amyloid targets, a significant effort is focused on targeting the metal-induced oxidative stress component of the disease. The main focus of research is based on modifications of existing drugs with specific biological activity. Tacrine was the first AChE inhibitor to be introduced into clinical practice and has been frequently used for the design of multitarget-directed ligands. A number of hybrid compounds containing tacrine and structural moieties derived from natural sources such as flavonoids [quercetin, rutin, coumarin, gallamine, resveratrol, scutellarin, anisidine, hesperetin, (−)-epicatechin] and other molecules (melatonin, trolox) have also been applied to function as multitarget-directed ligands. Most of these hybrids are potent inhibitors of AChE and butyrylcholinesterase and also of amyloid-beta aggregation. In addition, the antioxidant functionality, represented by coumarins, melatonin and other antioxidant molecules reduces the level of oxidative stress via ROS-scavenging mechanisms, as well as via chelation of redox-active Cu and Fe, thus suppressing the formation of ROS via the Fenton reaction. Various medicinal plants are under investigation for their ability to ameliorate symptoms of AD. The therapeutic potency of huperzine A and B, ginseng, curcumin and other compounds is manifested predominantly by the inhibitory action toward AChE, antioxidant or radical-scavenging and redox metal-chelating activity, inhibition of amyloid-beta aggregation and tau-protein hyperphosphorylation and antiinflammatory activity. Flavonoids not only function as antioxidants and metal-chelating agents, but also interact with protein kinase and lipid kinase signaling pathways, and others involving mitogen-activated protein kinase, NF-kappaB and tyrosine kinase. Among the most promising group of substances with potential activity against AD are the flavonoids, including myricetin, morin, rutin, quercetin, fisetin, kaempferol, apigenin and glycitein, which have been shown, in vitro, to possess antiamyloidogenic and fibril-destabilization activity, as well as being able to act as metal chelators and to suppressing oxidative stress. In terms of the clinical use of multifunctional hybrids, herbal drugs or flavonoids against AD, some remaining challenges are to establish the ideal dose to develop effective formulations to preserve bioavailability and to determine the stage when they should be administered. If the onset of the disease could be delayed by a decade, the number of AD victims would be significantly reduced.

The carcinogenicity of petroleum products is mainly due to their content of polycyclic aromatic compounds (PACs). These compounds may be activated metabolically and react with DNA to form DNA adducts, which is a critical event in the initiation of cancer. One of the most common techniques for analyzing DNA adducts is 32P-postlabeling. The chromatographic method often used has been 32P-TLC (thin-layer chromatography), but the more recently developed 32P-HPLC (high-performance liquid chromatography) method has shown advantages. The aim of this study was to test the hypothesis that the 32P-HPLC method has a better ability of detecting DNA adducts derived from petroleum products than 32P-TLC. It was found that some DNA adducts migrated from the application point in 32P-TLC in such a way that it is doubtful if they could be detected and quantified properly. It was also found that, when using 32P-HPLC, it is possible to use the same protocol for substances with a wide variety of DNA adduct forming potential, whereas 32P-TLC needs to be optimized regarding time of exposure and/or the amount of DNA applied. Further, a pattern of recognition in 32P-HPLC enables a selective assessment of DNA adducts derived from complex mixtures whereas 32P-TLC is very limited when analyzing complex mixtures due to poor resolution. With more knowledge about the properties of the most mutagenic DNA adducts in HPLC, it could be possible to know also which pattern corresponds to a mutagenic or carcinogenic oil. Consequently, 32P-HPLC is a good alternative when assessing the genotoxicity of petroleum products.

Drug-induced Mood- and Cognition-related adverse events (MCAEs) are often only detected during the clinical trial phases of drug development, or even after marketing, thus posing a major safety concern and a challenge for both pharmaceutical companies and clinicians. To fill some gaps in the understanding and elucidate potential biological mechanisms of action frequently associated with MCAEs, we present a unique workflow linking observational population data with the available knowledge at molecular, cellular, and psychopharmacology levels. It is based on statistical analysis of pharmacovigilance reports and subsequent signaling pathway analyses, followed by evidence-based expert manual curation of the outcomes. Our analysis: (a) ranked pharmaceuticals with high occurrence of such adverse events (AEs), based on disproportionality analysis of the FDA Adverse Event Reporting System (FAERS) database, and (b) identified 120 associated genes and common pathway nodes possibly underlying MCAEs. Nearly two-thirds of the identified genes were related to immune modulation, which supports the critical involvement of immune cells and their responses in the regulation of the central nervous system function. This finding also means that pharmaceuticals with a negligible central nervous system exposure may induce MCAEs through dysregulation of the peripheral immune system. Knowledge gained through this workflow unravels putative hallmark biological targets and mediators of drug-induced mood and cognitive disorders that need to be further assessed and validated in experimental models. Thereafter, they can be used to substantially improve in silico/in vitro/in vivo tools for predicting these adversities at a preclinical stage.

In the female reproductive tract, oocytes and embryos are in a dark environment, while during the in vitro fertilization (IVF) they are exposed to various visible and invisible lights such as daylight, microscope, and laminar hood fluorescent lights. Studies have shown that light could damage cellular compartments of oocytes and embryos and consequently decrease rates of fertilization, development, and blastocyst formation. However, due to the lack of consensus about the effects of light on the embryos, and subsequently the inability to make definitive decisions regarding the light exposure management to improve IVF results, in the present study, we systematically reviewed the effect of light with different wavelengths and intensities on pre-implantation embryos. The toxic impact of light depends on the wavelength, intensity, and duration of light exposure and also the stage of embryo. Therefore, reducing the observation time of embryos out of the incubator and also using light filters can alleviate the detrimental effect of light in IVF labs.

Sodium nitroprusside (SNP)-treated PC12 cell line is being used in our laboratory as a cell model of nitric oxide (NO)-mediated damage for in vitro evaluation of potential neuroprotective compounds, thus cell response to SNP must be standardized to gain reproducible data. The NO-donor SNP has been shown to induce cell death at high concentrations in undifferentiated PC12 cells. Differences were found in sensitivity to SNP between cells from short- and long-term cultured cells. After 24-h exposure to 100–500 μM SNP, a decrease of cell viability was observed in both short- (17, 21 and 23rd passages) and long-term cultures (46, 49 and 50th passages), with IC50 values of 312.72 and 462.90 μM, respectively. In cells from early passages, SNP-induced cell death was accompanied by significant increases of LDH leakage, nitrite production, malondialdehyde (MDA) levels, catalase (CAT) activity, cleavage of poly(ADP-ribose)polymerase (PARP) and caspase-3 activation in comparison with those from late passages. Furthermore, untreated and SNP-treated cells from long-term cultures displayed an increase of the stress protein Hsp70 levels when compared with those from short-term cultures. Up-regulated levels of Hsp70 may be associated with cell survival. Therefore, cells may acquire a certain resistance to SNP-induced toxicity associated with an increase in cell passage-dependent Hsp70. The protein Hsp70 might modulate the cellular response to the toxic insult by increasing CAT and GSH-Px activities and decreasing caspase-3 activation. Finally, it is crucial for the standardization of this cell model of neurotoxicity, at least in part, the use of PC12 cells in an optimum and reliable range of passages.

The current paradigm for explaining lung granulomatous diseases induced by inhaled particles is mainly based on macrophages. This mechanism is now challenging because B lymphocytes also infiltrate injured tissue, and the deficiency in B lymphocytes is associated with limited lung granulomas in silica-treated mice. Here, we investigated how B lymphocytes respond to micro- and nanoparticles by combining in vivo and in vitro mouse models. We first demonstrated that innate-like B-1 lymphocytes (not conventional B-2 lymphocytes or plasma cells) specifically accumulated during granuloma formation in mice instilled with crystalline silica (DQ12, 2.5 mg/mouse) and carbon nanotubes (CNT Mitsui, 0.2 mg/mouse). In comparison to macrophages, peritoneal B-1 lymphocytes purified from naïve mice were resistant to the pyroptotic activity of reactive particles (up to 1 mg/mL) but clustered to establish in vitro cell/particle aggregates. Mouse B-1 lymphocytes (not B-2 lymphocytes) in coculture with macrophages and CNT (0.1 µg/mL) organized three-dimensional spheroid structures in Matrigel and stimulated the release of TIMP-1. Furthermore, purified B-1 lymphocytes are sensitive to nanosilica toxicity through radical generation in culture. Nanosilica-exposed B-1 lymphocytes released proinflammatory cytokines and alarmins. In conclusion, our data indicate that in addition to macrophages, B-1 lymphocytes participate in micrometric particle-induced granuloma formation and display inflammatory functions in response to nanoparticles.

Fly ash (100 mg/kg body weight) was administered intratracheally to 14-day pregnant rats for 6 consecutive days. On day 20 of gestation the translocation of metals present in the fly ash to various maternal and fetal organs was studied. Fly ash administration to pregnant mothers retarded the growth of fetal heart and kidney as determined by their weights. Fly ash instillation increased organ levels of nearly all the metals studied in both mother and fetus. Most of the metals present in coal fly ash were transferred in significant amounts through placenta to several fetal organs. However, the pattern of their distribution into various fetal organs was different for different metals.