A Crucial Role of Proteolysis in the Formation of Intracellular Dinitrosyl Iron Complexes.

Dinitrosyl iron complexes (DNICs) stabilize nitric oxide in cells and tissues and constitute an important form of its storage and transportation. DNICs may comprise low-molecular-weight ligands, e.g., thiols, imidazole groups in chemical compounds with low molecular weight (LMWDNICs), or high-molecular-weight ligands, e.g., peptides or proteins (HMWDNICs). The aim of this study was to investigate the role of low- and high-molecular-weight ligands in DNIC formation. Lysosomal and proteasomal proteolysis was inhibited by specific inhibitors. Experiments were conducted on human erythroid K562 cells and on K562 cells overexpressing a heavy chain of ferritin. Cell cultures were treated with •NO donor. DNIC formation was monitored by electron paramagnetic resonance. Pretreatment of cells with proteolysis inhibitors diminished the intensity and changed the shape of the DNIC-specific EPR signal in a treatment time-dependent manner. The level of DNIC formation was significantly influenced by the presence of protein degradation products. Interestingly, formation of HMWDNICs depended on the availability of LMWDNICs. The extent of glutathione involvement in the in vivo formation of DNICs is minor yet noticeable, aligning with our prior research findings.

Coralyne Radiosensitizes A549 Cells by Upregulation of CDKN1A Expression to Attenuate Radiation Induced G2/M Block of the Cell Cycle.

Coralyne is a synthetic analog of berberine related to protoberberine-isoquinoline alkaloids. Isoquinoline derivatives and analogs are renowned as potent radiosensitizers with potential medical application. In the present study, we investigated the effect of coralyne on the cell death, cytoskeletal changes and cell cycle progression of irradiated A549 cells. A clonogenic assay revealed that coralyne pretreatment decreased the viability of A549 cells in a time- and dose-dependent manner. Moreover, exposure to coralyne and ionizing radiation (IR) markedly altered the filamentous actin cytoskeletal architecture and integrin-ß binding sites of A549 cells. Treatment with 1-25 µM coralyne in combination with 2 Gy of IR significantly reduced the percentage of cells in G2/M phase compared with 2 Gy IR alone. These results indicate that coralyne is a potent radiosensitizing agent that may find an application in medicine.

Design and Evaluation of 223Ra-Labeled and Anti-PSMA Targeted NaA Nanozeolites for Prostate Cancer Therapy-Part II. Toxicity, Pharmacokinetics and Biodistribution.

Metastatic castration-resistant prostate cancer (mCRPC) is a progressive and incurable disease with poor prognosis for patients. Despite introduction of novel therapies, the mortality rate remains high. An attractive alternative for extension of the life of mCRPC patients is PSMA-based targeted radioimmunotherapy. In this paper, we extended our in vitro study of 223Ra-labeled and PSMA-targeted NaA nanozeolites [223RaA-silane-PEG-D2B] by undertaking comprehensive preclinical in vitro and in vivo research. The toxicity of the new compound was evaluated in LNCaP C4-2, DU-145, RWPE-1 and HPrEC prostate cells and in BALB/c mice. The tissue distribution of 133Ba- and 223Ra-labeled conjugates was studied at different time points after injection in BALB/c and LNCaP C4-2 tumor-bearing BALB/c Nude mice. No obvious symptoms of antibody-free and antibody-functionalized nanocarriers cytotoxicity and immunotoxicity was found, while exposure to 223Ra-labeled conjugates resulted in bone marrow fibrosis, decreased the number of WBC and platelets and elevated serum concentrations of ALT and AST enzymes. Biodistribution studies revealed high accumulation of 223Ra-labeled conjugates in the liver, lungs, spleen and bone tissue. Nontargeted and PSMA-targeted radioconjugates exhibited a similar, marginal uptake in tumour lesions. In conclusion, despite the fact that NaA nanozeolites are safe carriers, the intravenous administration of NaA nanozeolite-based radioconjugates is dubious due to its high accumulation in the lungs, liver, spleen and bones.

Transient Vasodilation in Mouse 4T1 Tumors after Intragastric and Intravenous Administration of Gold Nanoparticles.

Gold nanoparticles (AuNPs) are foreseen as a promising tool in nanomedicine, both as drug carriers and radiosensitizers. They have been also proposed as a potential anticancer drug due to the anti-angiogenic effect in tumor tissue. In this work we investigated the effect of citrate-coated AuNPs of nominal diameter 20 nm on the growth and metastatic potential of 4T1 cells originated from a mouse mammary gland tumor inoculated into the mammary fat pad of Balb/ccmdb mice. To evaluate whether AuNPs can prevent the tumor growth, one group of inoculated mice was intragastrically (i.g.) administered with 1 mg/kg of AuNPs daily from day 1 to day 14 after cancer cell implantation. To evaluate whether AuNPs can attenuate the tumor growth, the second group was intravenously (i.v.) administered with 1 or 5 mg/kg of AuNPs, twice on day 5 and day 14 after inoculation. We did not observe any anticancer activity of i.v. nor i.g. administered AuNPs, as they did not affect neither the primary tumor growth rate nor the number of lung metastases. Unexpectedly, both AuNP treatment regimens caused a marked vasodilating effect in the tumor tissue. As no change of potential angiogenic genes (Fgf2, Vegfa) nor inducible nitric oxygenase (Nos2) was observed, we proposed that the vasodilation was caused by AuNP-dependent decomposition of nitrosothiols and direct release of nitric oxide in the tumor tissue.

Chlorpyrifos stimulates expression of vitamin D3 receptor in skin cells irradiated with UVB.

Skin, the organ responsible for vitamin D synthesis, is fully exposed to many xenobiotics, e.g. polycyclic aromatic hydrocarbons and pesticides. A broad spectrum organophosphorus insecticides (OP's), such as chlorpyrifos (CPS), are commonly used in agriculture and to control domestic insects. Thus, the aim of this study was to investigate the effect of chlorpyrifos, on the expression of vitamin D3 receptor (VDR) in human keratinocytes cell line HaCaT and fibroblasts cell line BJ. The impact of CPS and UVB radiation on cell viability were examined by Neutral Red assay. The effect of CPS on VDR expression was evaluated by RT-qPCR and flow cytometry (FC). The presented study demonstrated that exposure to CPS and UVB significantly affects the viability of HaCaT and BJ cells lines. Results also revealed that exposure to CPS induced the expression at mRNA and protein level of VDR nuclear receptor in both cell lines exposed to UVB. In HaCaT incubated with 250 µM CPS and 15 mJ/cm2 UVB, the relative VDR expression was ∼2-fold higher; whereas in BJ incubated with 250 µM CPS and 20 mJ/cm2, UVB was∼3-fold higher. Results from FC confirmed this result, as VDR expression increased by ~250% in HaCaT incubated with 250 µM CPS and 20 mJ/cm2 UVB, and in BJ incubated with 250 µM CPS, and 20 mJ/cm2 UVB cells VDR expression increased by ~190%, compared with control. It can therefore be concluded that OPs pesticide might interfere with vitamin D3 metabolism in skin cells.

Impact of silver, gold, and iron oxide nanoparticles on cellular response to tumor necrosis factor.

Metallic nanomaterials are utilized in an increasing number of applications in medicine and industry. Their general toxicity was tested in numerous reports both in vitro and in vivo but limited data exist on how nanomaterials affect the activity of cellular signaling pathways activated by growth factors and cytokines. The aim of the present work was to test the hypothesis predicting that silver, gold and superparamagnetic iron oxide nanoparticles may interfere with cellular signaling activated by tumor necrosis factor (TNF) and change the final cellular outcome of TNF action. Such interference may result in disruption of homeostasis and contribute to the development of malignancies such as cancer or autoimmune diseases. Experiments were performed on HepG2 and A549 cell lines. We did not observe any interaction between nanoparticles and TNF at the level of clonogenic growth, apoptosis/necrosis induction or cell cycle. At all these endpoints, the effects of TNF and nanoparticles were additive. In contrast, gene expression analysis revealed synergistic effects. A group of genes was significantly affected only by simultaneous treatment with TNF and nanoparticles and not by any of the factors alone. Observed synergistic effect on IL10 and IL8 expression seems to be of particular importance since these cytokines are often expressed by tumor cells to inhibit tumor-targeted immune response. The observed synergistic effects of TNF and nanoparticles on cytokines expression may have significant consequences for tissue homeostasis and tumor promotion and therefore should be taken into account during development of new nanoparticle-based anticancer therapies.

Adaptation of HepG2 cells to silver nanoparticles-induced stress is based on the pro-proliferative and anti-apoptotic changes in gene expression.

Silver nanoparticles (AgNPs) are one of the most widely used nanomaterials due to their antibacterial properties. Owing to the recent boost in the usage of AgNPs-containing products, human exposure to AgNPs is increasing, highlighting the need for careful evaluation of AgNPs toxicity in humans. We used two cellular models, hepatic HepG2 and epithelial A549 cell lines, to study the mechanism of AgNPs-induced toxicity at the cellular level. These two cell lines differ significantly in their response to AgNPs treatment. In the case of A549 cells, a minor decrease in viability and increase in the extent of DNA breakage were observed. A markedly different response to AgNPs was observed in HepG2 cells. In short term, a massive induction of DNA breakage was observed, suggesting that the basal activity of antioxidant defence in these cells was not sufficient to effectively protect them from the nanoparticle-induced oxidative stress. After prolonged exposure, the extent of DNA breakage decreased to the level observed in the control cells proving that a successful adaptation to the new conditions had taken place. The cells that were unable to adapt must have died, as revealed by the Neutral Red assay that indicated less than half viable cells after 24-h treatment with 100 µg/ml of 20nm AgNPs. The gene expression analysis revealed that the observed adaptation was underlain by a pro-proliferative, anti-apoptotic signal leading to up-regulation of the genes promoting proliferation and inflammatory response (EGR1, FOS, JUN, HK2, IL4, MMP10, VEGFA, WISP1, CEBPB, IL8, SELPLG), genes coding the anti-apoptotic proteins (BCL2A1, CCL2) and factors involved in the response to stress (HSPB1, GADD45A). Such a selection of highly resistant population of cells should be taken into account in the case of medical applications of nanoparticles since the sustained proliferative signalling and resistance to cell death are hallmarks of cancer, acquired by the cells in the process of carcinogenesis.

Toward the development of transcriptional biodosimetry for the identification of irradiated individuals and assessment of absorbed radiation dose.

The most frequently used and the best established method of biological dosimetry at present is the dicentric chromosome assay, which is poorly suitable for a mass casualties scenario. This gives rise to the need for the development of new, high-throughput assays for rapid identification of the subjects exposed to ionizing radiation. In the present study, we tested the usefulness of gene expression analysis in blood cells for biological dosimetry. Human peripheral blood from three healthy donors was X-irradiated with doses of 0 (control), 0.6, and 2 Gy. The mRNA level of 16 genes (ATF3, BAX, BBC3, BCL2, CDKN1A, DDB2, FDXR, GADD45A, GDF15, MDM2, PLK3, SERPINE1, SESN2, TNFRSF10B, TNFSF4, and VWCE) was assessed by reverse transcription quantitative PCR 6, 12, 24, and 48 h after exposure with ITFG1 and DPM1 used as a reference genes. The panel of radiation-responsive genes was selected comprising GADD45A, CDKN1A, BAX, BBC3, DDB2, TNFSF4, GDF15, and FDXR. Cluster analysis showed that ΔC t values of the selected genes contained sufficient information to allow discrimination between irradiated and non-irradiated blood samples. The samples were clearly grouped according to the absorbed doses of radiation and not to the time interval after irradiation or to the blood donor.

Cis-9,trans-11-conjugated linoleic acid affects lipid raft composition and sensitizes human colorectal adenocarcinoma HT-29 cells to X-radiation.

BACKGROUND: Investigations concerned the mechanism of HT-29 cells radiosensitization by cis-9,trans-11-conjugated linoleic acid (c9,t11-CLA), a natural component of human diet with proven antitumor activity. METHODS: The cells were incubated for 24h with 70µM c9,t11-CLA and then X-irradiated. The following methods were used: gas chromatography (incorporation of the CLA isomer), flow cytometry (cell cycle), cloning (survival), Western blotting (protein distribution in membrane fractions), and pulse-field gel electrophoresis (rejoining of DNA double-strand breaks). In parallel, DNA-PK activity, γ-H2AX foci numbers and chromatid fragmentation were estimated. Gene expression was analysed by RT-PCR and chromosomal aberrations by the mFISH method. Nuclear accumulation of the EGF receptor (EGFR) was monitored by ELISA. RESULTS AND CONCLUSIONS: C9,t11-CLA sensitized HT-29 cells to X-radiation. This effect was not due to changes in cell cycle progression or DNA-repair-related gene expression. Post-irradiation DSB rejoining was delayed, corresponding with the insufficient DNA-PK activation, although chromosomal aberration frequencies did not increase. Distributions of cholesterol and caveolin-1 in cellular membrane fractions changed. The nuclear EGFR translocation, necessary to increase the DNA-PK activity in response to oxidative stress, was blocked. We suppose that c9,t11-CLA modified the membrane structure, thus disturbing the intracellular EGFR transport and the EGFR-dependent pro-survival signalling, both functionally associated with lipid raft properties. GENERAL SIGNIFICANCE: The results point to the importance of the cell membrane interactions with the nucleus after injury inflicted by X -rays. Compounds like c9,t11-CLA, that specifically alter membrane properties, could be used to develop new anticancer strategies.

Basal PIR expression in HeLa cells is driven by NRF2 via evolutionary conserved antioxidant response element.

Pirin, a product of the PIR gene, is an iron-binding protein acting as a transcriptional coregulator implicated in the regulation of the NF-κB-related transcription via interaction with RelA (p65), as well as BCL3 and NF-κB1 (p50) proteins. Alterations in pirin expression were observed in various tumors and under oxidative stress conditions. The aim of the present work was to analyze the regulation of the transcription of the human PIR gene. Using constructs containing a different sized PIR promoter and the luciferase reporter genes we found that in HeLa cells PIR transcription is mostly dependent on a highly conserved antioxidant response element located 281 bp downstream of the transcription start site. We have proved that the NRF2 transcription factor binds to this element in vivo and drives the basal PIR expression. We hypothesize that regulation of the PIR expression may constitute a mechanism by which NRF2 is able to modulate the activity of NF-κB and possibly other signaling pathways.

Epigenetic modifications and NF-κB pathway activity in Cu,Zn-SOD-deficient mice.

The aim of this study was to examine the possible impact of Cu,Zn-SOD deficiency on the level of epigenetic modifications in different mouse tissues, and the relationship between these modifications and the NF-κB transcription factor activity. Cu,Zn-SOD deficiency did not influence the level of 5mdC or 5hmdC in the analyzed tissues. Statistically significant organ-/tissue-specific differences between the levels of 5mdC and 5hmdC were demonstrated within each genotype. Also correlations between analyzed parameters pointed to wide tissue/genotype variety; we observed a positive correlation between 5mdC and NF-кB proteins, p50 and RelA, in the liver of wild mice, as well as an inverse correlation between 5mdC and p65 in the brain of Cu,Zn-SOD-deficient animals. Moreover, a positive correlation was revealed between 5mdC and 5hmdC in the liver and brain of knockout mice. As the highest levels of both 5mdC and 5hmdC were observed in the brains of analyzed animals regardless of their genotype, and lower, comparable to each other, levels of these modifications were shown in the kidney and liver, active demethylation process seems to be tissue-/organ-specific and does not necessarily rely solely on the redox/oxidation state of cells. According to the most likely scenario, various tissues may differ in terms of their metabolic rates, which has potential influence on cofactors, and consequently on the activity of TET enzymes or activation of TET-independent mechanisms.

[Genetic predisposition to ischemic heart disease in patients with obstructive sleep apnea syndrome (OSAS)]. / Zaleznosc wystepowania choroby niedokrwiennej serca od polimorfizmu wybranych genów u chorych na obturacyjny bezdech senny (OBS).

The incidence of ischemic heart disease (IHD) in patients with OSAS is estimated at around 20%. This greatly affect a common risk factors for both diseases: male gender, obesity, age and diabetes and hypertension. Attention is drawn to the possibility of genetic determinants of IHD. The aim of study was to answer the question whether the presence of polymorphisms of selected genes possibly related to IHD may be useful to isolate the group of patients with OSAS, especially vulnerable as a complication of IHD. Materials and methods. The study included 600 people with OSAS, which was isolated in patients with IHD (127 people). The remaining 473 individuals were observed as a control group. The polymorphism of three genes were evaluated to find possible influence on the occurrence of IHD or myocardial infarction as follows: SREBF1 (sterol regulatory element binding transcription factor 1), REBF2 (sterol regulatory element binding transcription factor 2) and HIF1 (hypoxia inducible factor 1, alpha subunit). Results. Analysis of relationship between polymorphisms of selected genes and the diagnosis of IHD in the whole group of patients with OSAS showed a relationship only for the gene SREBF1 finding the lowest frequency of its occurrence in AA homozygotes (at 13.6%) and twice with GG homozygotes (26.1%). Conclusions. Rating polymorphisms studied genes did not reveal their relationship to the occurrence of IHD in patients with OSAS, both in the whole group as well as separate subgroups.

Calibration curve for radiation dose estimation using FDXR gene expression biodosimetry - premises and pitfalls.

PURPOSE: Radiation-induced alterations in gene expression show great promise for dose reconstruction and for severity prediction of acute health effects. Among several genes explored as potential biomarkers, FDXR is widely used due to high upregulation in white blood cells following radiation exposure. Nonetheless, the absence of a standardized protocols for gene expression-based biodosimetry is a notable gap that warrants attention to enhance the accuracy, reproducibility and reliability. The objective of this study was to evaluate the sensitivity of transcriptional biodosimetry to differences in protocols used by different laboratories and establish guidelines for the calculation of calibration curve using FDXR expression data. MATERIAL AND METHODS: Two sets of irradiated blood samples generated during RENEB exercise were used. The first included samples irradiated with known doses including: 0, 0.25, 0.5, 1, 2, 3 and 4 Gy. The second set consisted of three 'blind' samples irradiated with 1.8 Gy, 0.4 Gy and a sham-irradiated sample. After irradiation, samples were incubated at 37 °C over 24 h and sent to participating laboratories, where RNA isolation and FDXR expression analysis by qPCR were performed using sets of primers/probes and reference genes specific for each laboratory. Calibration curves based on FDXR expression data were generated using non-linear and linear regression and used for dose estimation of 'blind' samples. RESULTS: Dose estimates for sham-irradiated sample (0.020-0.024 Gy) and sample irradiated with 0.4 Gy (0.369-0.381 Gy) showed remarkable consistency across all laboratories, closely approximating the true doses regardless variation in primers/probes and reference genes used. For sample irradiated with 1.8 Gy the dose estimates were less precise (1.198-2.011 Gy) but remained within an acceptable margin for triage within the context of high dose range. CONCLUSION: Methodological differences in reference genes and primers/probes used for FDXR expression measurement do not have a significant impact on the dose estimates generated, provided that all reference genes performed as expected and the primers/probes target a similar set of transcript variants. The preferred method for constructing a calibration curve based on FDXR expression data involves employing linear regression to establish a function that describes the relationship between the logarithm of absorbed dose and FDXR ΔCt values. However, one should be careful with using non-irradiated sample data as these cannot be accurately represented on a logarithmic scale. A standard curve generated using this approach can give reliable dose estimations in a dose range from 50 mGy to 4 Gy at least.

Adverse Effects of Non-Metallic Nanoparticles in the Central Nervous System.

The interest in nanoparticles (NPs) and their effects on living organisms has been continuously growing in the last decades. A special interest is focused on the effects of NPs on the central nervous system (CNS), which seems to be the most vulnerable to their adverse effects. Non-metallic NPs seem to be less toxic than metallic ones; thus, the application of non-metallic NPs in medicine and industry is growing very fast. Hence, a closer look at the impact of non-metallic NPs on neural tissue is necessary, especially in the context of the increasing prevalence of neurodegenerative diseases. In this review, we summarize the current knowledge of the in vitro and in vivo neurotoxicity of non-metallic NPs, as well as the mechanisms associated with negative or positive effects of non-metallic NPs on the CNS.

Silver Nanoparticles Induced Changes in DNA Methylation and Histone H3 Methylation in a Mouse Model of Breast Cancer.

The importance of epigenetic changes as a measurable endpoint in nanotoxicological studies is getting more and more appreciated. In the present work, we analyzed the epigenetic effects induced by citrate- and PEG-coated 20 nm silver nanoparticles (AgNPs) in a model consisting of 4T1 breast cancer tumors in mice. Animals were administered with AgNPs intragastrically (1 mg/kg b.w. daily-total dose 14 mg/kg b.w.) or intravenously (administration twice with 1 mg/kg b.w.-total dose 2 mg/kg b.w.). We observed a significant decrease in 5-methylcytosine (5-mC) level in tumors from mice treated with citrate-coated AgNPs regardless of the route of administration. For PEG-coated AgNPs, a significant decrease in DNA methylation was observed only after intravenous administration. Moreover, treatment of 4T1 tumor-bearing mice with AgNPs decreased histone H3 methylation in tumor tissue. This effect was the most pronounced for PEG-coated AgNPs administered intravenously. No changes in histone H3 Lys9 acetylation were observed. The decrease in methylation of DNA and histone H3 was accompanied by changes in expression of genes encoding chromatin-modifying enzymes (Setd4, Setdb1, Smyd3, Suv39h1, Suv420h1, Whsc1, Kdm1a, Kdm5b, Esco2, Hat1, Myst3, Hdac5, Dnmt1, Ube2b, and Usp22) and genes related to carcinogenesis (Akt1, Brca1, Brca2, Mlh1, Myb, Ccnd1, and Src). The significance of the observed changes and the mechanisms responsible for their development are unclear, and more research in this area is warranted. Nevertheless, the present work points to the epigenetic effects as an important level of interaction between nanomaterials and biological systems, which should always be taken into consideration during analysis of the biological activity of nanomaterials and development of nanopharmaceuticals.

Silver Nanoparticles Inhibit Metastasis of 4T1 Tumor in Mice after Intragastric but Not Intravenous Administration.

The potential anticancer activity of different silver nanoformulations is increasingly recognized. In the present work, we use the model of 4T1 tumor in BALB/ccmdb immunocompetent mice to analyze the impact of citrate- and PEG-coated silver nanoparticles (AgNPs) on the development and metastatic potential of breast cancer. One group of mice was intragastrically administered with 1 mg/kg body weight (b.w.) of AgNPs daily from day 1 to day 14 after cancer cells implantation (total dose 14 mg/kg b.w.). The second group was intravenously administered twice with 1 or 5 mg/kg b.w. of AgNPs. A tendency for lowering tumor volume on day 21 (mean volumes 491.31, 428.88, and 386.83 mm3 for control, AgNPs-PEG, and AgNPs-citrate, respectively) and day 26 (mean volumes 903.20, 764.27, and 672.62 mm3 for control, AgNPs-PEG, and AgNPs-citrate, respectively) has been observed in mice treated intragastrically, but the effect did not reach the level of statistical significance. Interestingly, in mice treated intragastrically with citrate-coated AgNPs, the number of lung metastases was significantly lower, as compared to control mice (the mean number of metastases 18.89, 14.90, and 8.03 for control, AgNPs-PEG, and AgNPs-citrate, respectively). No effect of AgNPs treatment on the number of lung metastases was observed after intravenous administration (the mean number of metastases 12.44, 9.86, 12.88, 11.05, and 10.5 for control, AgNPs-PEG 1 mg/kg, AgNPs-PEG 5 mg/kg, AgNPs-citrate 1 mg/kg, and AgNPs-citrate 5 mg/kg, respectively). Surprisingly, inhibition of metastasis was not accompanied by changes in the expression of genes associated with epithelial-mesenchymal transition. Instead, changes in the expression of inflammation-related genes were observed. The presented results support the antitumor activity of AgNPs in vivo, but the effect was limited to the inhibition of metastasis. Moreover, our results clearly point to the importance of AgNPs coating and route of administration for its anticancer activity. Finally, our study supports the previous findings that antitumor AgNPs activity may depend on the activation of the immune system and not on the direct action of AgNPs on cancer cells.

Alterations in the expression of genes related to NF-κB signaling in liver and kidney of CuZnSOD-deficient mice.

NF-κB signaling pathway plays a central role in regulation of the cellular response to stress. Among numerous factors that modulate NF-κB dependent transcription, reactive oxygen species attracted special attention. In the present work, we compared the expression of 84 genes related to NF-κB signaling between cytosolic superoxide dismutase (CuZnSOD)-deficient and wild-type mice. In kidney, we found seven genes which expression was significantly affected by CuZnSOD deficiency. Among them, four were up-regulated, Egr1, Fos, Il1b, Tnfrsf10b, and three down-regulated, Card10, Ikbkb, Tgfbr2. In the case of liver, six genes were up-regulated, Fos, Il1b, Il1r1, Jun, Tlr7, Tnfrsf10b, and five down-regulated, Casp8, Ikbke, Irak1, Nfkb1, Raf1. The results demonstrate that CuZnSOD deficiency has a significant impact on the expression of NF-κB related genes in both kidney and liver. The differences in gene expression reported in our work may contribute to understanding of the molecular mechanisms underlying phenotypic abnormalities in CuZnSOD-deficient mice, e.g., increase in the incidence of liver cancer.

[Dinitrosyl iron complexes--structure and biological functions]. / Dinitrozylowe kompleksy zelaza--budowa i znaczenie biologiczne.

Formation of dinitrosyl iron complexes (DNICs), which can be described by general formula Fe(NO)2(L)2, where L is carbonyl-, nitrosyl- or imino- complexing ligand, was observed in many kinds of living organisms, in a wide spectrum of physiological conditions associated with inflammation, ischemia/reperfusion and cancer. Accumulation of DNICs coincides with intensified production of nitric oxide in macrophages, neurons, endothelial cells, Langerhans' cells and hepatocytes. Low-molecular thiol-containing DNICs (DNIC-(RS)2) show vasodilatory action and they are proposed to play a role of nitric oxide transducers and stabilizers. DNICs have been shown to modulate redox potential of the cell via inhibition of glutathione-dependent enzymes, such as glutathione reductase, S-transferase and peroxidase. Although there is a convincing experimental evidence for their NO and NO+ donating function, the nature of DNICs formed in biological systems, their stability and biological role is still a matter of discussion.

The Impact of Ag Nanoparticles and CdTe Quantum Dots on Expression and Function of Receptors Involved in Amyloid-ß Uptake by BV-2 Microglial Cells.

Microglial cells clear the brain of pathogens and harmful debris, including amyloid-ß (Aß) deposits that are formed during Alzheimer's disease (AD). We studied the expression of Msr1, Ager and Cd36 receptors involved in Aß uptake and expression of Cd33 protein, which is considered a risk factor in AD. The effect of silver nanoparticles (AgNPs) and cadmium telluride quantum dots (CdTeQDs) on the expression of the above receptors and Aß uptake by microglial cells was investigated. Absorption of Aß and NPs was confirmed by confocal microscopy. AgNPs, but not CdTeQDs, caused a decrease in Aß accumulation. By using a specific inhibitor-polyinosinic acid-we demonstrated that Aß and AgNPs compete for scavenger receptors. Real-time PCR showed up-regulation of Cd33 and Cd36 gene expression after treatment with CdTeQDs for 24 h. Analysis of the abundance of the receptors on the cell surface revealed that AgNP treatment significantly reduced the presence of Msr1, Cd33, Ager and Cd36 receptors (6 and 24 h), whereas CdTeQDs increased the levels of Msr1 and Cd36 (24 h). To summarize, we showed that AgNP uptake competes with Aß uptake by microglial cells and consequently can impair the removal of the aggregates. In turn, CdTeQD treatment led to the accumulation of proinflammatory Cd36 protein on the cell surface.

Nuclear Factor kappa B activation by Ag, Au nanoparticles, CdTe quantum dots or their binary mixtures in HepG2 cells.

INTRODUCTION AND OBJECTIVE: Nuclear factor kappa B (NF-κB) signalling pathway plays a central role in the regulation of cellular response to stress. The aim of the study was to investigate the ability of silver nanoparticles (AgNPs), gold nanoparticles (AuNPs), CdTe quantum dots (CdTeQDs) or their binary mixtures to stimulate NF-κB binding in HepG2 cells. A dual luciferase reporter system was used to investigate NF-κB binding. MATERIAL AND METHODS: Cells were transiently transfected with a firefly luciferase reporter system and Renilla luciferase expression plasmid as a transfection efficiency control. Twenty- four hours after transfection, the cells were treated with nanoparticles (10 µg/cm3 AgNPs, 10 µg/cm3 AuNPs, 3 µg/cm3 CdTeQDs) or with 10 ng/cm3 TNFα as a positive control. Six hours later, the cells were lysed and the activities of the luminescence of firefly and Renilla luciferases were measured using the Dual-Luciferase Reporter Assay System. RESULTS: AuNPs and CdTeQDs alone significantly inhibited NF-κB binding activity. Co-treatment with AgNPs and CdTeQDs resulted in an additive effect, whereas the presence of AgNPs diminished the inhibitory effect of AuNPs. Interestingly, significant antagonism was observed between AuNPs and CdTeQDs, suggesting a similar mode of action. CONCLUSIONS: Comparison of the NF-κB binding activity induced by the mixtures of NPs suggests that in some cases NF-κB binding activity might differ from that observed for the NPs alone.