Oxidative stress and activation of H2A.X in lung alveolar epithelial cells (A549) by nanoparticulate carbon black

Fine airborne particulate matter enter the respiratory system, induce oxidative stress and initiate DNA damage. The aim of our study was the estimation of cell viability, oxidative stress, DNA damage, cell cycle alterations and activation of histone H2A.X. Experiments were done on lung alveolar epithelial (A549) cells grown for 24 h with 200 µg mL-1 coarse carbon black (CB), or nanoparticulate CB (NPCB). Neither CB nor glutathione depletion altered cell viability, growth rates, and H2A.X expression while NPCB decreased cell viability, increased oxidative stress and DNA damage. The cell cycle was blocked at G0/G1. NPCB but not CB increased expression and activation of H2A.X at mRNA and protein levels. Co-expression data point to γH2A.X as a major NPCB target, and show the interdependence of γH2A.X and oxidative stress. We conclude, that NPCB increases γ-H2A.X expression in A549 cells at mRNA and protein levels and stimulates H2A.X (Ser139), phosphorylation, associated with oxidative stress, the DNA damage response and G1 cell cycle arrest.

Co-expression of Hsp70 Protein and Autophagy Marker Protein LC3 in A549 Cells and THP1 Cells Exposed to Nanoparticles of Air Pollution

The ability of air particulate matter (PM) to cause reactive oxygen species-driven protein damage is associated with both COPD and lung cancer, but the mechanisms are unsettled. In this study, we investigated the co-expression of Hsp70 and the autophagy marker protein LC3 in A549 cells (alveolar epithelial cell line) and THP-1 cells (monocyte/macrophage cells) grown in media supplemented with 100 μg/mL of four types of PM: carbon black (CB), urban dust (UD), nanoparticulate CB (NPCB), and nanoparticulate CB coated with benzo(a)pyrene (NPCB-BaP). Fluorescent monoclonal antibodies and flow cytometry were used to assess the expression and co-expression of HSP70 and LC3 proteins. Hsp70 expression was significantly increased by all PM, while LC3 was decreased by CB in A549 cells, unchanged by CB and UD in THP-1 cells and increased by NPCB and NPCB-BaP in both cell types. All PMs increased the Hsp70/LC3 ratio in binary scatterplots; the relationship was positive and linear, which may reflect chaperone-dependent autophagy. The UD was the only PM type that affected the slopes of the spatial trend lines and altered binary patterns of Hsp70/LC3 distribution in THP1 cells. These findings provide an insight into the molecular mechanisms regulating proteostasis in PM-exposed cells through the chaperone-autophagy system in the cytoplasm.

Sialidase Attenuates Epidermal Growth Factor Response and Abolishes Antiproliferative Effects of Erlotinib in A549Alveolar Epithelial Cells

Erlotinib is a widely used, reversible tyrosine kinase inhibitor (TKI), targeting pro-proliferative signaling of epidermal growth factor receptor (EGFR). The drug is approved for the first-line treatment of patients with metastatic non-small cell lung cancer with EGFR mutations. Extracellular glycans can affect EGFR expression, dimerization, phosphorylation, and EGF binding. In this study we investigated the effects of EGF and erlotinib on the cell cycle of naive and sialidase (alpha-neuraminidase)-pretreated human A549 alveolar epithelial cells. A549 cells were labeled with propidium iodide, and fractions of cells in different phases of cycle were quantified by flow cytometry. We found that neither did desialilation nor EGF, as well as erlotinib treatment, increase the number of damaged cells (subG0/G1 cell fraction), while erlotinib did significantly increase the number of G0/G1 cells and decrease S + G2/M cell fractions. In naive cells, EGF increased proliferating cell numbers by more than 40%, and this effect was blocked by erlotinib. In desialylated cells, however, proliferation was significantly decreased by about 29%, and EGF and erlotinib did not exert significant effects. We conclude that changes in alveolar epithelial cell membrane glycosylation may affect function of growth-promoting receptors and erlotinib effectiveness.

Cigarette Smoke-Induced Oxidative Stress and Autophagy in Human Alveolar Epithelial Cell Line (A549 Cells)

Chronic exposure to cigarette smoke (CS) causes structural and functional changes in the respiratory tract. It is a major risk factor for cardiovascular and systemic pulmonary diseases. The aim of this study was to investigate the effect of acute CS exposure (2 h) on oxidative stress, heat shock protein 70 (HSP70) expression, autophagy (LC3 expression), and oxidative stress (DCF fluorescence) in human alveolar epithelial cell line A549. Cell culture medium was conditioned with CS using commercial cigarettes, and A549 cells were grown in modified media for 2 h. In some experiments, A549 cells were pretreated with 100 μM of L-buthionine-sulfoximine (BSO) for 24 h to induce glutathione (GSH) depletion. In the cells grown in CS-conditioned medium, GSH was depleted by more than 30%, and reactive oxygen species were increased. Moreover, there was a considerable overexpression of HSP70 and a substantial accumulation of LC3. Similar changes were found when the cells were pretreated with BSO. We conclude that the short-term exposure of epithelial cells to CS increases oxidative stress that entails enhanced autophagy activity.

Costs of Treatment of Chronic Obstructive Pulmonary Disease

The aim of this study was to analyze direct costs of COPD therapy in relation with clinical course and stage of the disease. Sixty patients with moderate to severe COPD were included into the study. The average cost was taken from institutional data file and was also assessed from a social perspective. Results were presented as average costs per patient per year. Forty two percent of patients was classified as GOLD D category, while categories A, B, and C accounted for 8 %, 27 %, and 23 %, respectively. Approximately 65 % of patients had 2-3 degrees of dyspnea according to the Modified Medical Research Council Dyspnea Scale. About 60 % of patients underwent two or three exacerbations per year and those patients had one or two co-morbidities diagnosed. Treatment costs almost doubled with disease progression, mainly due to exacerbations. In patients in Group C and Group D with exacerbations the direct costs were several times higher than in group A or B and the difference increased with progression of the disease. In Groups A and B, the costs of treatment of stable disease or with exacerbation were comparable. We conclude that costs of treatment of COPD patients were highest in advanced disease and were strongly related to COPD exacerbations.

Inhaled corticosteroids increase siglec-5/14 expression in sputum cells of COPD patients

Recent studies show that several Siglec receptors, such as Siglec-8 and Siglec-14, may be important therapeutic targets in asthma and COPD. Siglecs are a family of lectins belonging to the immunoglobulin superfamily and recognize sialic acid residues of glycoproteins. Most of Siglecs have intracellular immunoreceptor tyrosine-based inhibitory motifs (ITIM), implicating them in the suppression of immunoreceptor signaling. Siglec-5/14 may be involved in the negative regulation of innate immune responses. The aim of this study was to analyze Siglec-5/14 expression in induced sputum cells of COPD patients in the following treatment combinations: (1) a long-acting beta2-agonist, formoterol; (2) formoterol combined with a long-acting antimuscarinic agent, tiotropium; and (3) formoterol combined with an inhaled corticosteroid or formoterol combined with tiotropium and with an inhaled corticosteroid. Siglec expression was assessed in sputum cells by flow cytometry using a specific monoclonal antibody. Double staining of cells indicated that Siglec-5/14 is expressed in monocyte/macrophages and neutrophils, but not in lymphocytes. Siglec-5/14 expression was significantly higher in patients receiving combined therapy including inhaled corticosteroids compared with patients taking only formoterol or formoterol + tiotropium. Our results suggest that inhaled corticosteroids may exert beneficial or negative effects, depending on the patients' phenotype, through increased immunosuppressive Siglec-5 or immunoactivatory Siglec-14 receptors, respectively.

Crosstalk Between Co-cultured A549 Cells and THP1 Cells Exposed to Cigarette Smoke

Cigarette smoke (CS) is considered as a major etiological factor in the pathogenesis of chronic obstructive pulmonary disease. In this study we used A549 cells and THP-1 cells grown for 24 h in monoculture or in co-culture in CS-conditioned media and changes in their proliferation, viability, acetylated histone H3 levels and expression of extracellular antigens CD14, HLA-DR, CD11a, and CD11b were assessed. CS was highly toxic to A549 cells but not to THP1 cells. In A549 cells, oxidative stress reached the highest values after 1 h of CS exposure and then decreased. In THP1 cells oxidative stress was lower and increased progressively with time. CS decreased proliferation of A549 and THP1 cells by about 80% and 21%, respectively. CS did not alter acetylated histone H3 levels in A549 cells, while in THP1 cells the levels were reduced by about 35%. CS significantly increased expression of CD14, HLA-DR, CD11a, and CD11b in THP1 cells. In co-culture, naïve or CS-pretreated THP1 cells significantly protected A549 cells against CS toxicity but had higher death rates. These results show that epithelial cells are more fragile to CS than monocytes and that CS-activated monocytes may protect epithelial cells against CS-induced cytotoxicity.

Siglec-8 in induced sputum of COPD patients

Chronic obstructive pulmonary disease (COPD) is related to infiltration and activation of inflammatory cells in airways and pulmonary tissue. In COPD, neutrophils are prominent, while eosinophilic influx is typical to asthma. Inflammatory cells express sialic acid-binding immunoglobulin like lectins called Siglecs, a family of innate immune receptors that are transmembrane I-type lectins binding sialic acid. One member of the Siglec family, Siglec-8, is expressed mostly in eosinophils and may be an important therapeutic target in asthma or COPD. The aim of our project was to quantify Siglec-8 expression in induced sputum cells of COPD patients treated with long-acting beta2-agonists (LABA) or combined with long-acting antimuscarinic agents (LAMA) - tiotropium bromide. Thirty stable COPD patients (21 males and 9 females, mean age 67 years) receiving 12 μg BID formoterol therapy were assessed before and after 3 months' add-on therapy consisting of 18 μg QID tiotropium. In all patients, spirometry, lung volumes, and DLCO were performed before and after therapy. The patients were subjected to sputum induction before and after therapy. Sputum cells were isolated and processed to obtain cell membranes. Siglec-8 protein expression was assessed using Western blot. In patients receiving tiotropium and formoterol, improved FEV1 and lung volumes were observed compared with formoterol-only treated patients. The mean Siglec-8 level was significantly higher in eosinophilic subgroup of COPD patients compared with non-eosinophilic patients before therapy 40,000 vs. 15,000 Adj. Vol. INT/mm(2). Our data show that Siglec-8 may be involved in COPD pathogenesis and may influence COPD phenotyping.

Lipopolysaccharide changes sialylation pattern in the mouse central nervous system

Sialylated glycoconjugates seem to play crucial role in the mechanisms that control the most important functions of the body. Sialylation is an important mechanism for the regulation of intercellular interactions that underlie neuronal plasticity as well as immune defense in the central nervous system (CNS). In this study, we analyzed the effect of lipopolysaccharide (LPS) on sialylation pattern in several regions of CNS. Additionally, we tested the effects of inflammatory stimulation on Siglec-F expression in microglial cells. Using lectin blotting with Maackia amurensis and Sambucus nigra agglutinins and immunostaining with antibody directed against PSA-NCAM we demonstrated altered expression of sialylated glycoconjugates differentially due to LPS-induced inflammation. We found that LPS caused significant increase of α2,3- and α2,6-linked sialic acids in the hippocampus and spinal cord. In the prefrontal cortex, the level of α2,3-linked sialic acids in selected glycoconjugates tended to be increased (p>0.05), while α2,6-linked sialic acids were reduced (p<0.05), while the expression of PSA-NCAM in all analyzed structures were significantly higher in comparison to the control group. The expression of Siglec-F in microglial cells stimulated with LPS remained unchanged. Given the significance of glycans in the brain biology we can conclude that sialic acids and their receptors Siglec may be crucial regulators of immune response in the CNS.

Cerebrospinal fluid IL-6, TNF-α and MCP-1 in children with acute lymphoblastic leukaemia during chemotherapy

The aim of the study was to investigate the levels of cerebrospinal fluid (CSF) cytokines during chemotherapy of acute lymphoblastic leukaemia (ALL). Examination of 12 ALL child (6 boys and 6 girls) patients evidenced significant increases in interleukin-6 (IL-6) and monocyte chemotactic protein-1 (MCP-1) after induction treatment and significant increases in IL-6, tumour necrosis factor-α (TNF-α) and MCP-1 levels during the consolidation phase, as compared to their values at the time of diagnosis. There were no significant differences in CSF IL-6, TNF-α and MCP-1 concentrations after therapy. Our data suggest that standard ALL treatment may cause a subclinical inflammation and neurotoxicity.

Increased FKBP51 in induced sputum cells of chronic obstructive pulmonary disease patients after therapy

Objective

Immunophilin FKBP51 assists polypeptide folding, participates in glucocorticoid actions and may play a role in glucocorticoid resistance. FKBP51 is altered in patients with asthma, but its role in chronic obstructive pulmonary disease (COPD) characterized by dysregulation of several pro/antiinflammatory genes is less clear.

Methods

We assessed changes in nuclear/cytosolic FKBP51 protein using SDS-PAGE/WB and FKBP51 mRNA by qRT-PCR in cells isolated from induced sputum of stable COPD patients treated with formoterol/budesonide or formoterol/budesonide/theophylline for 4 wk.

Results

Expression of FKBP51 was higher in formoterol/budesonide/theophylline-treated patients, compared with formoterol/budesonide group in both cytosolic and nuclear fractions by about 57% and 31%, respectively (P < 0.001, P < 0.01). FKBP51 mRNA was only slightly, but not significantly, higher in patients on formoterol/budesonide/theophylline.

Conclusions

Increased FKBP51 in COPD patients treated with formoterol/budesonide/theophylline may be important in altering signaling from corticosteroid receptors.

Nuclear HSP90 and HSP70 in COPD patients treated with formoterol or formoterol and corticosteroids

Objective

Heat shock proteins assist cellular protein folding and are required for the normal activity of steroid receptors. In this study we assessed nuclear HSP90 and HSP70 proteins and mRNA levels in cells isolated from induced sputum of chronic obstructive pulmonary disease patients treated for 4 weeks with formoterol (F) or formoterol+budesonide (F/ICS).

Methods

Nuclear heat shock protein levels were assessed by Western blot and specific mRNAs were quantified in cell lysates using qRT-PCR.

Results

Both HSP90 and HSP70 protein levels were higher in the F/ICS-treated patients in comparison with the F-treated group (by 31%, P < 0.05 and 28%, P < 0.05, respectively), while specific mRNAs were lowered. HSP86/HSP89 and D6S182/HSP90-BETA were repressed by about 40% (P < 0.05)whileHSP70-1/HSP70-1A, HSP70-1B/HSP70-2, and HSP70-HSC54/HSC70 were repressed by 47% (P < 0.01), 57% (P < 0.01) and 65% (P < 0.01), respectively.

Conclusions

It is possible that increased nuclear heat shock proteins may play a role in the attenuation of the response to glucocorticoids in COPD patients.

Propofol protects rat astroglial cells against tert-butyl hydroperoxide-induced cytotoxicity; the effect on histone and cAMP-response-element-binding protein (CREB) signalling

Propofol can be potentially beneficial in oxidative stress related malignancies as neurodegenerative diseases and traumatic brain injury but its signalling pathways are poorly understood. In this study effect of propofol on astroglial signalling in oxidative stress was evaluated. Ten days old cultures of rat astroglial cells were treated for 1 hour with t-butyl hydroperoxide (tBHP) to induce oxidative stress following by 1 hour propofol. We measured cytotoxicity, changes in cell growth and apoptosis as well as alterations in expression and acetylation of chromatin core H3 and H4 histone proteins and changes in native and phosphorylated cAMP-response-element-binding protein (CREB). tBHP induced limited cytotoxicity, increased apoptosis, decreased glutamine synthetase and enolase activities, decreased nuclear CREB, CREB-P and histone proteins but unchanged cytosolic CREB and histone acetyltransferase (HDAC) expression. Propofol clearly protected the cells against tBPH-induced toxicity, normalized alterations in cell growth, restored to some extent glial enzyme activities and reduced apoptotic cell numbers. Also, propofol restored H3 but not H4 expression/activation, but was without effect on decreased nuclear CREB expression/activation. These data show that oxidative stress in cultured astroglia significantly affects nuclear CREB and histone proteins and point to the protective role of propofol.

Cerebrospinal fluid changes in the excitatory amino acids concentration caused by the standard treatment of acute lymphoblastic leukaemia in children do not correlate with their later cognitive functioning

The aim of this study was to ascertain whether changes in the concentrations of cerebrospinal fluid excitatory amino acids (EAAs) contribute to neurotoxicity of the standard acute lymphoblastic leukaemia (ALL) treatment protocols. We found a statistically significant increase in glutamate and aspartate in 12 ALL patients during their treatment. Cognitive functioning was examined in all patients at an average of 3.7 years after the disease diagnosis. Importantly, the levels of EAAs during the therapy were not correlated with the results of the cognitive test. This study suggests that standard ALL treatment-induced neurotoxicity may not lead to persistent neurocognitive deficits.

Expression of CREB-binding protein and peroxisome proliferator-activated receptor gamma during formoterol or formoterol and corticosteroid therapy of chronic obstructive pulmonary disease

We assessed the effect of therapy on nuclear signaling related to inflammatory processes in sputum cells of patients with chronic obstructive pulmonary disease (COPD). Patients were treated with formoterol (F) or formoterol plus budesonide (F/ICS) b.i.d. for 4 weeks, their sputum cells were isolated and subjected to RNA extraction or lysis, followed by differential centrifugation. Signaling protein levels were assessed by Western blots, their specific mRNAs were quantified using qRTPCR, while 8-isoprostane levels were examined using enzyme immunoassay kit. Cytosolic 8-isoprostane levels and nuclear glucocorticoid receptor expression (protein and mRNA) were not significantly different in both groups, while nuclear cAMP response element binding protein (CREB; protein and mRNA) and peroxisome proliferator-activated receptor gamma (PPARgamma protein and mRNA) were significantly higher in cells from F/ICS-treated patients. CREB-binding protein (CBP; protein and mRNA) levels were significantly lower in F/ICS patients. These changes indicate increased anti-inflammatory signaling in F/ICS-treated patients and seem to be beneficial.

Chronic obstructive pulmonary disease: an update on nuclear signaling related to inflammation and anti-inflammatory treatment

Chronic obstructive pulmonary disease (COPD) is one of the most frequent diseases worldwide. Cigarette smoke is considered the main pathological cause of the disorder, although evidence is growing concerning other etiological factors, such as environmental pollution, biomass combustion, infections, genetic predisposition, which may explain why some individuals develop COPD with no history of smoking. Chronic inflammation and remodeling of the small airways characterize the disease at the cellular level, and oxidative stress is considered the main driving force that stands behind COPD inflammation. Recently, chromatin remodeling and epigenetic changes have been found to underlie disease pathology and progression. In this review, the authors gave a short update on the recent hypothesis and findings that may imply novel approach to pharmacotherapy of the disease, focusing on the role of glucocorticosteroids, theophylline, and antioxidants.

Cytoplasm-nuclear trafficking of CREB and CREB phosphorylation at Ser133 during therapy of chronic obstructive pulmonary disease

cAMP responsive element binding protein (CREB) plays an important role in transcriptional machinery. CREB signaling is altered in patients with asthma. However, the role of CREB in chronic obstructive pulmonary disease (COPD) is less clear. In the present study we assessed changes in subcellular CREB distribution and activation (CREB-P) in 35 stable COPD patients treated with formoterol (F), formoterol+budesonide (F/ICS), and formoterol+budesonide+theophylline (F/ICS/Th) b.i.d. for 4 weeks, using SDS-PAGE/WB in cytosol and nuclear extracts of induced sputum cells. The expression of CREB was increased after F/ICS in both cytosolic and nuclear fractions by about 40% and 24%, respectively (P<0.001, P<0.01), while CREB-P increased after F/ICS by about 50% (P<0.01) in both compartments. These changes were not affected by theophylline. In F/ICS-treated patients, relative accumulation of CREB in cytosol was observed. These findings indicate, that poor response to ICS therapy may be related to increased CREB-associated signaling.

Molecular basis of chronic inflammation in lung diseases: new therapeutic approach

There is increasing evidence that histone acetylation, controlled by histone acetyltransferases (HAT), reversed by histone deacetylases (HDAC) plays a critical role in the process of regulation of inflammatory genes and in mediating the anti-inflammatory effects of corticosteroids in asthma patients. There is evidence of an increase in HAT activity in asthmatics, which leads to increased expression of multiple inflammatory genes that are regulated by proinflamatory factors, such as nuclear factor NF-kappaB. Reduction in HDAC activity, secondary to oxidative and nitrative stress and severe inflammation, may account for the amplified inflammation in chronic obstructive pulmonary disease (COPD). Corticosteroids switch off inflammatory genes through the inhibition of HAT activity and by recruitment of HDAC2 to the activated transcription complex. Several new strategies to control inflammations in COPD, aiming at restoration of the HDAC-2 activity and/or mitigation of HAT-related signaling are in the preclinical and clinical development.

Therapy increases poly-ADP-ribose and p53-Ser392-P levels in recurrent squamous cell lung cancer

p53 protein is a critical regulator of the cell cycle and apoptosis and its levels and functions change in response to many stimuli. To assess whether the cytotoxic drugs induce DNA changes, affect phosphorylation and stability of p53 protein, we determined poly-ADP-ribose levels, the expression of p53 protein and its carboxyl-terminal Ser-392 phosphate levels in fiberoptic bronchoscopy biopsy samples taken from patients suffering from recurrent squamous cell lung cancer before and after radiotherapy and chemotherapy. All 14 patients included in this study were in IA-IIIA clinical stage prior to surgery. Radiation/chemotherapy decreased G2/M cell numbers but increased S-phase cells by almost 50% compared to ploidy status before therapy, while median p53 expression was doubled (109% increase). p53 phosphorylated on Ser-392 was also increased by approximately 70% in patients treated with radiotherapy and with chemotherapy and correlated with elevated poly-ADP-ribose levels. Our data suggest that apart from changes in p53 quantity, posttranslational phosphorylation/dephosphorylation-mediated alterations may play an important role in neoplastic cell proliferation as well as in antiproliferative activity of drugs inducing DNA damage and apoptosis.

Proliferating activity, DNA ploidy changes of lung cancer cells before and after chemotherapy

To assess proliferating activity, DNA ploidy changes of lung cancer cells before and after chemotherapy, we performed a flow cytometry analysis (FC) using fresh bronchoscopy specimens from 38 patients with lung cancer. Among 33 males and 5 females, squamous cell carcinoma (NSLC) was recognized in 12 males, 15 males had small cell lung cancer (SCLC) and 6 males had lung cancer with no histological type (LC) defined. Three women had SCLC, 1 had NSCLC and one had LC. Control consisted of 11 COPD patients. The percentage of diploid cells was significantly lower and cells with hypoploid cells were significantly higher in study group before treatment. High percentage of G2M cells characterised NSCLC and LC groups, whether high number of S phase cells characterised NSCLC and SCLC group before treatment. The treatment lowered percentage of G2M cells in NSCLC and CA group, whether diploid, hypoploid and S phase cells did not differ than those from before treatment.

Role of neutrophils in release of some cytokines and their soluble receptors

Available data suggest that cytokines and soluble cytokine receptors, which are being produced by immunological cells, can modulate the immune response of the host. Although the production of mediators such as TNF-alpha and IL-6 as well as that of their soluble receptors has been extensively studied in tissue cells and mononuclear cells, it has not been fully investigated in neutrophils (PMN). In the present study we examined the ability of PMN to simultaneously release TNF-alpha, IL-6 and their soluble receptors-sTNFRp55, sTNFRp75 and sIL-6R. Concentrations of soluble receptors were compared with expression of membrane-bound TNF and IL-6 receptors. For comparative purposes, similar examinations with autologous peripheral blood mononuclear cells (PBMC) were performed. We found that PMN and PBMC have the same ability to release IL-6 and sTNFRp75. In contrast, there were significant differences in the release of TNF-alpha, sTNFRp55 and sIL-6R between these cells. Reduction in membrane TNF receptor expression, observed in this study, was associated with increase secretion of soluble TNF receptors by PMN and PBMC. The results suggest that PMN can play an essential role in modulating the inflammatory response by affecting the balance between pro-inflammatory mediators, such as TNF-alpha, and anti-inflammatory mediators, such as soluble TNF receptors.

Acetaldehyde cytotoxicity in cultured rat astrocytes

The effect of acetaldehyde on astrocytes have been investigated because not only do they play an important role in brain maturation but also recent reports have shown their delayed proliferation following both 'in vivo' and 'in vitro' ethanol exposure. Biochemical parameters related to apoptotic and necrotic processes were examined in primary cultures of rat astrocytes exposed for 4 days to acetaldehyde generated from ethanol by co-cultured alcohol dehydrogenase-transfected Chinese hamster ovary cells. Acetaldehyde levels in the culture media attained concentrations of approximately 450 microM. To study ethanol effects, alcohol oxidation was inhibited by 4-methylpyrazole (an inhibitor of alcohol dehydrogenase). Acetaldehyde but not ethanol increased intracellular calcium levels by 155%. Moreover, significant DNA fragmentation was detected using a random oligonucleotide primed synthesis assay, by flow cytometry and when using agar gel electrophoresis. Transglutaminase activity was elevated in the cells treated with acetaldehyde but when acetaldehyde formation was inhibited by 4-methylpyrazole the enzyme activity was unaffected. Nitrate levels in the culture media were unchanged. Additionally, microscopic examination of cell nuclei revealed chromatin condensation in astrocytes exposed to acetaldehyde. It can be concluded, that in 'in vitro' acetaldehyde exposed rat astrocytes apoptotic pathways are activated.

Evaluation of the influence of N-nitrosodimethyloamine (NDMA) on the apoptosis of neutrophils of peripheral blood (PMN) and the expression of the IL-6R membrane receptor--in vitro research

Evaluation of the influence of N-nitrosodimethyloamine (NDMA) on the apoptosis of neutrophils of peripheral blood (PMN) and the expression of the IL-6R membrane receptor - in vitro research. The aim of the present work was the evaluation of N-nitrosodimethyloamine (NDMA) on the induction of apoptosis in the neutrophils of peripheral blood as well as the evaluation of the surface receptors for IL-6. The isolated neutrophils were incubated for 1 and 3 hours with NDMA of a concentration of 2.5, 5, 7.5, and 10 mg/ml. In the samples incubated for 1 hour a significant, dose- dependent increase of apoptosis in the examined cells was observed. In the cells incubated for 3 hours, the increase of apoptosis was observed only at concentration of NDMA of 2.5 and 5 mg/ml. In case of higher concentration used, probably necrotic processes dominated in the cells. No influence of NDMA on the expression of IL-6R was observed.

Paternal alcohol exposure: developmental and behavioral effects on the offspring of rats

The effect of paternal alcohol exposure on neurochemical and behavioral parameters was investigated using as a model system glial cells derived from newborn rat brain and cultured for 4 weeks. The total brain neurochemical parameters from rats born to mothers sired by an alcohol treated father were also investigated. Enzymatic markers of nerve cell development (enolase isoenzymes and glutamine synthetase) and the defense system (superoxide dismutase) against free radicals formed during alcohol degradation were measured in order to evaluate nerve cell damage. Behavioral locomotor tests (open-field, novelty-seeking, light/dark) were carried out to show long-lasting effects of paternal alcoholization on the offspring. Behavioral and developmental alterations were found until 1 year of age in the offspring and a significant growth retardation was observed in the males. Our results suggest that paternal alcohol exposure produces developmental and behavioral effects in the offspring. The consequence of either alcohol withdrawal during stage one spermatogenesis, or maternal diet supplementation with manganese during pregnancy were investigated. It was observed that some of the effects of paternal alcohol exposure on the offspring may be reversed by these treatments.

The role of calcium in paracetamol (acetaminophen) cytotoxicity in PC12 cells transfected with CYP4502E1

Paracetamol-induced toxicity is mainly due to the accumulation of its CYP450-mediated N-hydroxylation product - N-acetylimidoquinone. We examined cell viability, proliferation rates and intracellular calcium in PC12 cells and in a PC12 cell line transfected with cytochrome P4502E1 exposed to paracetamol. This drug had a concentration-related effect on cell survival and a LD(50) which was significantly different between both cell types. A 48% decrease of PC12 cells was found following application of 5 mmol/L paracetamol for 48 h. A total 73% decrease in cell numbers was found in cells metabolizing the drug. Culture protein levels were diminished in a similar manner. Paracetamol increased intracellular calcium (by 662%) only in CYP4502E1-transfected cells. The protective role of EGTA and verapamil modulating calcium homeostasis was more evident in CYP4502E1-transfected cells. These results suggest that biotransformation of paracetamol by CYP2E1 increases its cytotoxicity and that a calcium imbalance may have a key role in the initiation of cell injury.

Acetaminophen metabolism and cytotoxicity in PC12 cells transfected with cytochrome P4502E1

Although a number of studies confirm the important role of metabolites in the cytotoxicity of acetaminophen, its precise mechanisms remain unknown. Acetaminophen is metabolized by microsomal enzymes. Cytochrome P4502E1 (CYP2E1) mediated N-hydroxylation results in the formation of N-acetyl-benzo-quinoneimine, a highly reactive intermediate. We examined biochemical parameters related to necrotic and apoptotic processes in acetaminophen-exposed PC12 cells is and in a PC12 cell line genetically engineered to express human CYP2E1. Both the [3H]thymidine incorporation test and the protein assay uniformly showed dose- and time-related significant growth retardation in both cell lines exposed to the drug. This was more evident in CYP2E1-transfected cells. Moreover, the cytotoxic effect of acetaminophen was increased as evidenced by lactate dehydrogenase activity in the culture medium. Both random oligonucleotide primed synthesis assay and enzyme-linked immunosorbent assay revealed significant DNA fragmentation in both cell lines, which was greater in transfected cells, reaching about 11% of total cellular DNA. These results were confirmed by flow cytometry and microscopic examination of cell nuclei. Intracellular calcium levels were increased only in transfected cells, approximately threefold when 5 mM acetaminophen was administered for 48 h. These results indicate the cytotoxic effects of acetaminophen via apoptosis, necrosis, and growth retardation. While the precise mechanism remains obscure, it seems that DNA fragmentation and apoptotic cascade represent a preliminary biochemical event in acute cell death, and that acetaminophen bio-transformation by CYP2E1 stimulates this pathway.

Ethanol-induced cell death in cultured rat astroglia

Because of the important role of glial cells in brain maturation and reports on their delayed proliferation following ethanol exposure, it was considered of interest to investigate the mechanism of ethanol action on these cells. Biochemical parameters related to the apoptotic and necrotic processes in astroglial cells exposed for 1 week to 50 and 100 mM ethanol were examined. Ethanol increased intracellular calcium levels without changing transglutaminase activity and nitrite levels. Moreover, DNA fragmentation was noted with flow cytometry and with the random oligonucleotide primed synthesis assay but neither following agar gel electrophoresis nor in UV microscopy of cell nuclei. The DNA patterns obtained were different from these seen in programmed cell death. Additionally, immunocytochemical analysis showed greater fragility of astrocytes than oligodendrocytes to ethanol. These results support the hypothesis that astroglial cells in vitro exposed to ethanol die due to necrotic but not apoptotic mechanisms.

Effect of acetaldehyde generated from ethanol by ADH-transfected CHO cells on their membrane fatty acid profiles

Ethanol has been previously shown to reduce the unsaturated fatty acid content of cell membranes. It is not known, however, if the observed deleterious effects are due to ethanol itself or its metabolite, acetaldehyde. The present study was undertaken to assess the effect of acetaldehyde produced from ethanol by alcohol-deyhdrogenase-transfected Chinese hamster ovary Cells on the membrane lipids and the lipid peroxidation measured by free and bound malondialdehyde (MDA). The effects of ethanol alone was assessed in the presence of 4-methylpyrazole (4-MP), an inhibitor of alcohol dehydrogenase. After 8 days of incubation, total cellular lipids were extracted, subjected to TLC, and analyzed by gas chromatography. MDA concentration were determined by thiobarbituric acid reaction followed by HPLC detection. The level of acetaldehyde in the culture medium increased with concentration of ethanol from 5 to 20 mM as did the lipid peroxidation. Total cholesterol, phospholipids, and triglycerids all increased with increasing concentration of acetaldehyde. These effects were due to acetaldehyde as they were blocked by 4-MP. Some changes in fatty acid profiles were observed by effect of ethanol itself.

Development of glial cells cultured from prenatally alcohol treated rat brain: effect of supplementation of the maternal alcohol diet with a grape extract

The aim of this work was to investigate the effect of supplementation of a maternal alcohol diet with a grape extract on glial cell development. Glial cells were cultured during 4 weeks from cortical brain cells of the new born offspring in DMEM medium supplemented with fetal calf serum. Enzymatic markers of nerve cell development were measured (enolase isoenzymes and glutamine synthetase). Since alcohol consumption produces free radicals the antioxidant system superoxide dismutase was also investigated. Compared to the decrease found in only alcohol treated animals, all parameters except neuron-specific enolase were antagonized and even stimulated after grape extract supplementation. The effect was more important after only 1 month than 3 months of treatment. Also in the total brain an alcohol antagonizing effect and a glutamine synthetase activation were found. Our data demonstrate that addition of a grape extract to the maternal alcohol diet may partially or completely overcome the alcohol induced retardation of glial cell development.

Acetaldehyde-induced growth inhibition in cultured rat astroglial cells

Due to the important role of glial cells in brain maturation and reports on delayed astroglial proliferation following ethanol exposition, it was of great interest to examine the effects of the primary metabolite of ethanol--acetaldehyde--on astroglial cell growth. This was carried out by examining biochemical parameters of astroglial cells cocultured with Chinese hamster ovary cell line (CHO) transfected with alcohol dehydrogenase (ADH), able to generate acetaldehyde from ethanol. Acetaldehyde generated from ethanol by ADH-transfected CHO cells had an inhibitory effect on the growth of astroglial cells as assessed by measuring marker enzyme activities and culture protein levels. Moreover, both acetaldehyde and ethanol altered cell cycle and increased astroglial superoxide dismutase activity. Additionally, acetaldehyde, but not ethanol, increased malondialdehyde levels in cultured astroglia. These results clearly show that acetaldehyde may participate in the development of the Fetal Alcohol Syndrome.

The effect of ethanol on HSP70 in cultured rat glial cells and in brain areas of rat pups exposed to ethanol in utero

Prenatal exposure to alcohol is associated with a cluster of symptoms called Fetal Alcohol Syndrome with a characteristic pattern of neuroanatomy and biochemical changes. In recent years it has been shown, that stress exposed cells rapidly increase transcription and translation of heat shock protein genes resulting in an increased appearance of these proteins. It has also been found that heat shock proteins, especially the HSP70 family play a role as molecular chaperons maintaining the native conformation of proteins and participating in protein transport in particular cellular compartments. The aim of this study was to determine the effect of chronic maternal alcohol consumption on HSP70 content in the different regions of the brain of the newborn rats as well as to examine in vitro the effect of ethanol on HSP70 content in cultured glial cells. Chronic maternal ethanol consumption resulted in increased HSP70 in the following regions of developing brain: hippocampus, cerebellum, olfactory bulbs, frontal cortex and septum. Moreover, ethanol applied in vitro, increased HSP70 content in primary astroglial cultures and astrocytes but not in oligodendrocyte cultures. The above described changes may be important in brain maturation and may play a role in Fetal Alcohol Syndrome.

Inhibition of non-enzymatic lipid peroxidation by 'Essentiale' a drug enriched in phosphatidylcholine in ethanol-induced liver injury

The effect of 'Essentiale'--a drug, now clinically listed in European countries in the treatment of liver diseases was examined in ethanol-induced liver injury in rats (free access to a 20% ethanol solution for 3 months). The antioxidant enzymes, SOD (superoxide dismutase), CAT (catalase), GSH-R (glutathione reductase), non-protein and total SH groups as well as TBA-rs contents were investigated. Following treatment, we found beneficial effects in SOD and CAT activities. The above enzyme activities were restored after a 3-month drug administration. Furthermore, 'Essentiale' treatment normalized TBA-rs levels in the liver. These effects have been briefly discussed.

The effect of heparegen on antioxidant enzyme activities in ethanol-induced liver injury in rats

SOD, CAT, GSH-Px, and sulfhydryl compounds MDA contents in liver of rats treated with heparegen for 7, 14, and 21 days after alcoholic liver injury have been investigated. After use of this drug, we found beneficial effects on GSH-Px activity, sulfhydryl compounds (total and nonprotein), and MDA content and a partially beneficial effect on SOD and CAT activities. These enzyme activities after 21 days of drug administration were restored. Furthermore, heparegen shortens the time necessary for the return of AIAT and GGTP to normal value. This enzymatic data are supported by histological studies in light microscopy.

The decrease of superoxide dismutase activity and depletion of sulfhydryl compounds in ethanol-induced liver injury

There appears to be increasing evidence that ethanol toxicity may be associated with an increased production of reactive oxygen intermediates. In rats we studied the effect of 4 weeks of ethanol ingestion on the liver cytosolic defense system against active oxygen species. Compared with the control rats, the ethanol-fed animals had a significantly higher liver malondialdehyde content and significantly lower reduced glutathione level. Moreover, ethanol feeding resulted in a decrease of superoxide dismutase and catalase activities while glutathione peroxidase activity was only slightly diminished. Thus, prolonged ethanol administration profoundly modified the hepatic status of the enzymatic defense system leading to lipid peroxidation that may disrupt vital functions of liver cells.

The effect of immunostimulatory drugs on sulfhydryl compounds in plasma, liver and brain after ethanol-induced liver injury in rats

Sulfhydryl compounds in plasma, liver and brain of rats treated with two immunostimulant drugs, isoprinosine and levamisole, after alcoholic liver injury have been investigated. After use of both drugs for 6 days we found partially beneficial effect on the SH-groups in plasma and liver. No changes in nonprotein SH compounds were observed in rat brain after treatment with isoprinosine, levamisole or ethanol. Furthermore, levamisole shortens the time necessary for the return of AlAT activity to normal value.

The effect of Heparegen and D-penicillamine on the activity of some ammonia metabolizing enzymes in liver and brain of rats intoxicated with ethanol

This paper reports data on the effect of two drugs: Heparegen (thiazalidine-4-carboxylic acid) and D-penicillamine on the blood ammonia concentration and on some ammonia metabolizing enzymes in liver and brain of rats intoxicated with ethanol. It seems, that both drugs decrease ammonia concentration and simultaneously elevate liver and brain glutamine synthetase activity. The effect of D-penicillamine on the nitrogen metabolism in the damaged liver appears to be more favorable than that of Heparegen.

The changes in sulfhydryl compounds in plasma, liver and brain after acute and chronic ethanol administration in rats

The content of sulfhydryl compounds in proteins and non-proteins of plasma, liver and brain after acute and chronic ethanol administration was investigated in rats. After ethanol ingestion for 4 weeks (6 g/kg, day 30% w/v) significant changes were observed in plasma proteins and in liver proteins and non-proteins. In brain proteins and non-proteins we did not find any changes in sulfhydryl compounds content after acute and chronic ethanol administration.

Plasma and liver amino acids in rats after administration of ethanol or acetaldehyde

The changes in the level and pattern of free amino acids in plasma and liver after ethanol or acetaldehyde intoxication has been investigated in rats. After administration of 30% (w/v) ethanol, 6 g kg-1, or 1.5% (w/v) acetaldehyde, 0.3 ml kg-1, for 4 weeks we found a decrease in plasma and liver branched-chain amino acids and an increase in plasma aromatic amino acids and methionine. The results are analogous to those found in studies of damaged liver.