Maciej Roslan

Electronic cigarettes (ECs) are promoted as a safer alternative to traditional cigarettes, yet their impact on immune cells remains incompletely understood. This study investigates the activation of human primary adherent and non-adherent monocytes exposed ex vivo to aerosols from four flavored ECs (classic tobacco, menthol, watermelon, and strawberry) compared to cigarette smoke (CS) and nicotine alone. EC aerosols (ECEs) induced modest cytotoxicity, oxidative stress, and superoxide dismutase activity compared to CS, with high cell response heterogeneity indicating subpopulation-specific effects. Adherent monocytes showed elevated integrin expression (CD11a, CD11b), ICAM-1 (CD54), TNFα, and oxidative stress versus non-adherent cells, amplified by ECE. Dual fluorescence flow cytometry (green DCF for ROS and red for anti-TNFα Ab) revealed shifts toward pro-inflammatory/oxidative quadrants, particularly upper-right high-intensity relatively small subsets with macrophage M1-like CD68 expression in adherent cells. ECEs reduced phagocytosis in adherent monocytes, mimicking CS effects, probably driven by non-nicotine components. Strawberry flavor (ECE 4) elicited the strongest TNFα induction. These findings demonstrate EC-induced subclinical inflammation via selective monocyte activation, potentially contributing to chronic cardiopulmonary risks despite significantly lower overall toxicity than CS.

This study investigated the pro-inflammatory and pro-oxidative effects of popular electronic cigarette aerosols (ECAs) compared with conventional cigarette smoke (CS) in the cultured human alveolar epithelial cell line (A549). Using cytotoxicity assays and four ECAs, 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 ECAs 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 ECAs, and unaltered mitochondrial transmembrane potential, 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 the CS and ECA groups, with IL-6 consistently increased, underscoring its role in regulating epithelial cells. Advanced double fluorescence analysis revealed increased cellular heterogeneity and inflammation, which was distinct for all ECA flavours. Overall, the findings demonstrate considerable heterogeneity in biological effects among ECA flavourings and propose a simple ECA biomonitoring model. The results emphasise the necessity for individualised toxicity assessments, especially regarding subclinical inflammation and potential long-term health outcomes.

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.

Fine inhalable particulate matter (PM) triggers an inflammatory response in the airways and activates mononuclear cells, mediators of tissue homeostasis, and tumour-promoting inflammation. We have assessed ex vivo responses of human monocytes and monocyte-derived macrophages to standardised air pollutants: carbon black, urban dust, and nanoparticulate carbon black, focusing on their pro-inflammatory and DNA-damaging properties. None of the PM (100 μg/mL/24 h) was significantly toxic to the cells, aside from inducing oxidative stress, fractional DNA damage, and inhibiting phagocytosis. TNFα was only slightly increased. PM nanoparticles increase the expression and activate DNA-damage–related histone H2A.X as well as pro-inflammatory NF-κB. We have shown that the urban dust stimulates the pathway of DNA damage/repair via the selective post-translational phosphorylation of H2A.X while nanoparticulate carbon black increases inflammation via activation of NF-κB. Moreover, the inflammatory response to lipopolysaccharide was significantly stronger in macrophages pre-exposed to urban dust or nanoparticulate carbon black. Our data show that airborne nanoparticles induce PM-specific, epigenetic alterations in the subsets of cultured mononuclear cells, which may be quantified using binary fluorescence scatterplots. Such changes intercede with inflammatory signalling and highlight important molecular and cell-specific epigenetic mechanisms of tumour-promoting inflammation.

This study aimed to assess the acute and delayed cytotoxicity of three, popular light-cured methacrylate-based restorative resins (MRs): Charisma (C), Estelite (E), and Filtek (F), to human gingival fibroblasts in culture. Cells were grown for up to 24 h with light-cured (or pre-cured) resins. We evaluated resin cytotoxicity, redox imbalance, necrosis/apoptosis, miR-9, and heat shock protein 70 (HSP70). The role of resin-induced oxidative stress (damage) in HSP70-response (repair) was assessed using binary fluorescence labeling. All MRs decreased viable cell numbers and cell proliferation and damaged cell membranes, and their 24 h-delayed toxicity was lower (C), higher (F), or similar (E) to that induced by freshly-cured resins. Cell membrane damage induced by C and E decreased with time, while F produced a linear increase. All resins generated intracellular oxidative stress with the predominant necrotic outcome, and produced heterogeneous responses in miR-9 and HSP70. The double fluorescence (damage/repair) experiments pointed to common features of E and F but not C. In the subset of cells, the binary response induced by E and F was different from C, similar to each other, and positively interrelated. Experimental data show that selective MR cytotoxicity should be taken into account when considering repetitive use or massive reconstruction.