Adam Holownia

This study investigated the proinflammatory and prooxidative effects of popular electronic cigarette (EC) aerosols compared with conventional cigarette smoke (CS) in cultured human alveolar epithelial cell line (A549). Using cytotoxicity assays and four EC extracts, substantial differences in biological impact were observed. CS exposure led to significant declines in cell viability and pronounced morphological changes, consistent with the presence of toxic combustion byproducts. Most EC extracts caused negligible cytotoxicity except for the tobacco-flavoured variant, which demonstrated marked toxicity. DNA damage and altered cell cycle profiles were minor. Oxidative stress analysis revealed stable superoxide dismutase activity but notable glutathione depletion, especially with watermelon and strawberry-flavoured ECs, indicating the importance of individual flavour additives in cellular antioxidant defence. Inflammatory markers such as TNF-α, NF-κB, and IL-6 were differentially elevated across CS and EC groups, with IL-6 consistently increased, underscoring its role in epithelial cell regulation. Advanced double fluorescence analysis highlighted increased cellular heterogeneity and inflammation, distinct for all EC flavours. Overall, the findings demonstrate considerable heterogeneity in biological effects among EC flavourings and propose a simple biomonitoring model. The results emphasise the necessity for individualised toxicity assessments, especially regarding potential long-term health outcomes.

In this study we assessed microRNA-9 (miR-9) levels (RT-PCR) and cell proliferation (flow cytometry) in naïve and desialylated human alveolar epithelial cells (A549 cells), grown for 24 h in cigarette smoke-conditioned medium. Cells were additionally treated with lipopolysaccharide (LPS) and/or dexamethasone. Proliferation positively correlated with miR-9 levels in both naïve and desialylated cells. Cigarette smoke decreased miR-9 levels in both cell types by about three-fold but there was no significant correlation between both parameters. Dexamethasone was without substantial effect on cigarette smoke-induced changes in proliferation of naïve cells, but some normalization was observed in desialylated cells. Dexamethasone increased miR-9 levels in both cell types grown in cigarette smoke-medium but the effect was stronger in desialylated cells. LPS increased cell proliferation and miR-9 by more than six-fold only in naïve cells, while correlation coefficient for both parameters in cigarette smoke-LPS group was 0.41. Herein we identify miR-9 as the cigarette smoke (decrease) and LPS-responsive but dexamethasone-unresponsive microRNA. It is possible that increased miR-9 levels in naïve A549 cells treated with LPS may be related to the activation of Toll-like receptor 4. Moreover, differences in cell response (both miR-9 and proliferation) to dexamethasone in naïve and desialylated cells may point to non-genomic dexamethasone effects.

Cigarette smoke (CS) activates inflammatory cells and increases cytokine levels producing local and systemic inflammation. To assess changes in intracellular and extracellular cytokine levels we used human epithelial (A549 cells) and monocyte (THP-1) cell lines grown for 24 h in cigarette smoke-conditioned media. Cytokines were assessed using immunostaining/flow cytometry and ELISA assay. In THP1cells, grown in CS-conditioned media, the intracellular interleukins IL-1β, IL-6, and IL-10 increased by more than tenfold, while less significant increases were found in A549 cells. IL-1α and IL-1β, but not IL-6 or IL-10, were increased in the culture media, while IL-2 was raised by about fivefold only in the culture medium of A549 cells. IL-4, IL-6, IL-8, IL-10, IL-12, and tumor necrosis factor alpha were undetectable, while only a slight increase was observed in extracellular IL-17A (by about 60 %) in the medium of A549 cells and by about 115 % in the medium of THP1 cells. The interferon gamma (IFNγ) was increased by about eightfold, but only in the medium of THP1 cells grown with CS. We conclude that IL-1 and INFγ are the key cytokines responsible for pro-inflammatory signaling in epithelial cells and monocytes, respectively, 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.

Immune cells expressing the activation markers HLA-DR and regulatory T cells (Tregs) may be involved in the regulation of chronic inflammation in chronic obstructive pulmonary disease (COPD). In this study we analyzed native and activated cell profiles in sputum of 22 stable COPD patients receiving formoterol (F) or formoterol + tiotropium (F + T) for 3 months. Cells were isolated from induced sputum and were examined on Coulter flow cytometer using fluorescent antibodies specific for CD3, CD4, CD8, CD14, CD19, CD25, CD127, and HLA-DR antigens. Cell profiles and cell activation were assessed by analysis of HLA-DR, CD25, and CD127 co-expression in double-stained samples. Tregs were defined as CD4⁺CD25^high CD127^low cells. We found that the combined therapy significantly decreased the CD8⁺ cell number (p < 0.01). At baseline, HLA-DR was expressed in about 10 % of sputum T or B cells and a higher expression was found on monocytes. The HLA-DR expression on lymphocytes, but not monocytes, was significantly lower (p < 0.01) in patients treated with F + T. Fractions of activated [CD4⁺ CD25⁺] cells were also significantly lower in the combined therapy group, except for the subpopulation of CD4⁺CD25^high CD127^low cells which was not altered. We conclude that tiotropium in add-on therapy to formoterol affects Treg cell profiles and decreases HLA-DR expression in airway lymphocytes.

The aim of this work was to assess the role of ethanol-derived acetate and acetate-mediated histone acetylation in arachidonic acid-induced stress in HepG2 cells and cells overexpressing CYP2E1. Cells were grown for 7 days with 1 mM sodium acetate or 100 mM ethanol; their acetylated histone proteins and histone deacetylase 2 expression was quantified using Western blot. Ethanol- or acetate-pretreated cells were also treated for 24 h with 60 μM arachidonic acid to induce oxidative stress. Cytotoxicity was estimated by lactate dehydrogenase release, 3-[4,5-dimethylthiazolyl-2] 2,5-diphenyltetrazolium bromide test, and by DNA damage, while oxidative stress was quantified using dichlorofluorescein diacetate. Cells grown with ethanol or acetate had increased acetylated histone H3 levels in both cell types and elevated acetylated histone H4 levels in cells overexpressing CYP2E1 but not in naïve cells. In cells overexpressing CYP2E1 grown with ethanol, expression of histone deacetylase 2 was reduced by about 40 %. Arachidonic acid altered cell proliferation and was cytotoxic mostly to cells engineered to overexpress CYP2E1 but both effects were significantly lower in cells pretreated with ethanol or acetate. Cytotoxicity was also significantly decreased by 4-methylpyrazole—a CYP2E1 inhibitor and by trichostatin—an inhibitor of histone deacetylases. In cells pretreated with acetate or ethanol, the oxidative stress induced by arachidonic acid was also significantly lower. Our data indicate that histone hyperacetylation may in some extent protect the cells against oxidative stress. It is possible that acetate may act as an antioxidant at histone level. This mechanism may be relevant to alcohol-induced liver injury.

Chronic obstructive pulmonary disease (COPD) is the only major disease with increasing death rate. In COPD, progressive reduction in quality of life is closely related to the increasing limitation of airflow due to chronic bronchitis, cell hyperplasia, fibrosis, and irreversible lung damage. Signaling pathways involved in inflammatory processes in COPD and inflammatory response to therapy are unknown. Our aim was to isolate cells from induced sputum of COPD patients treated with formoterol or formoterol + tiotropium and assess enzymatic activity of histone deacetylases (HDACs) acetylated histone 4 (AcH4) and expression of inducible nitric oxide synthase (iNOS). HDACs are important in signal transduction and inflammation. iNOS is generating nitric oxide (NO) relevant to blood pressure regulation, inflammation and infections. Thirty stable COPD patients (21 males and 9 females, mean age 67 years) receiving 12 μg b.i.d. formoterol were assayed before and after 3 months add-on therapy consisting of 18 μg q.i.d. tiotropium. In all patients, spirometry, lung volumes, and DLCO were performed before and after tiotropium therapy and all patients were subjected to sputum induction. Sputum cells were isolated and processed to obtain cytosolic and nuclear fractions. HDAC activity was measured in nuclear fraction using colorimetric assay. Expression AcH4 and iNOS was quantified using Western blot. In patients receiving both drugs, FEV1 and lung volumes significantly improved compared with formoterol–only treated patients. Mean HDAC activity was slightly decreased (P < 0.05), while AcH4 levels and iNOS expression were significantly elevated in tiotropium-treated patients (increase by about 65 %; P < 0.01 and 77 %; P < 0.01 respectively). Our data show that beneficial effects of tiotropium in add-on therapy to formoterol may be related to altered histone signaling and increased iNOS expression.

Chronic obstructive pulmonary disease (COPD) is characterized by progressive airflow limitation and chronic inflammation of airways and lung parenchyma. Our aim was to assess two important elements of intracellular signaling involved in regulation of inflammation in COPD in patients subjected to long-acting beta2-agonist or long-acting beta2-agonist plus long-acting antimuscarinic: peroxisome proliferator-activated receptor gamma (PPARγ) protein, which has antiinflammatory and immunomodulatory properties and cAMP response element binding protein (CREB) and activated (CREB-P) protein which has histone acetyltransferase activity and increases histone acetylation and transcriptional activation of chromatin. Twenty one stable COPD patients (18 males and 3 females, mean age 65 years) receiving 12 μg B.I.D formoterol were assayed before and after 3 month add-on therapy, consisting of 18 μg Q.D. tiotropium. In all patients, sputum induction, spirometry, lung volumes, and DLCO were performed before and after therapy. Sputum cells were isolated and processed to isolate cytosolic and nuclear fractions. PPARγ, CREB, or CREB-P proteins were quantified in subcellular fractions using Western blot. Tiotropium add-on therapy improved respiratory parameters: FEV1 and lung volumes. After therapy mean expression of PPARγ in cell nuclei was significantly increased by about 180%, while CREB and phosphorylated CREB levels in cytosol and nuclei were decreased by about 30%. Our data show that the mechanism whereby tiotropium reduces exacerbations may be associated not only with persistent increase in airway functions and reduced hyperinflation mediated by muscarinic receptors, but also with possible anti-inflammatory effects of the drug, involving increased PPARγ and decreased CREB signaling.

Chronic obstructive pulmonary disease (COPD) is characterized by irreversible progressive airflow limitation related to tobacco smoking. This limitation is caused by chronic inflammation of the airways and lung parenchyma and is associated with increased activity of parasympathetic system. The most effective bronchodilators in COPD are muscarinic receptor antagonists (MRA), which reverse, at least in part, compromised respiratory function. MRA also contribute to control inflammatory processes via interactions with inflammatory signaling molecules. The use of the long-acting cholinolytic bronchodilatator - tiotropium, with high affinity to M3 receptors, is suggested as a first line maintenance treatment in COPD patients. In this study we assessed M3 receptor protein expression in induced sputum of 27 stable COPD patients before and after therapy consisting of 18 μg once daily tiotropium for 12 weeks. Lung function tests including spirometry, lung volumes, and DLCO were performed before and after therapy in all COPD patients. The patients were subjected to the sputum induction procedures before and after therapy. Sputum cells were isolated, sample-specific cell profiles were characterized, and the cells were processed to isolate pure cytosolic fractions. Cytosolic M3 protein and HDAC2 levels and nuclear acetylated histone H3 (AcH3) expression was quantified using specific antibodies against human proteins and Western blot with enhanced luminescence detection. Therapy significantly increased the mean forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) volume (P<0.05). The mean expression of M3 protein was higher by 37% after therapy (P<0.05), HDAC2 expression was not altered, while AcH3 level was increased by about 90% (P<0.01), compared with the corresponding data before therapy. HDAC2 expression before therapy was positively correlated with AcH3 expression (r = 0.74), while after therapy no correlation was detected. FEV1, FCV, and cytosolic M3 protein expression did not correlate with other biochemical parameters tested. Twelve weeks of tiotropium therapy in COPD patients improves clinical indices of lung function and involves alterations in sputum cell chromatin acetylation and also increased cholinergic M3 receptor internalization.

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). Nuclear heat shock protein levels were assessed by Western blot and specific mRNAs were quantified in cell lysates using qRT-PCR. 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) while HSP70-1/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. It is possible that increased nuclear heat shock proteins may play a role in the attenuation of the response to glucocorticoids in COPD patients.