Exposure cigarette smoke (CS) during prenatal life is the leading cause of preventable premature death. In this study, we explored the hypothesis that in vitro exposure of fetal lung cells to cigarette smoke extract (CSE) may result in the alteration of apoptosis through activation of caspase-3. Alongside we compared the responses of fetal lung cells with A549 cells and rat periodontal ligament (PDL) fibroblasts exposed to CSE in a dose dependent manner. Caspase-3 activity and inhibition was measured using a fluorometric assay. Cell viability in smoke exposed cells was measured using MTT formazan assay. Caspase-3 expression and cellular localization was detected by western blot analysis and immunofluorescence. Our results indicate that caspase-3 activity was significantly (p < 0.05) elevated and cell viability was significantly inhibited in fetal rat lung cells exposed to 10% or 15 % (v/v) CSE. No significant differences were observed in the caspase-3 activity or cellular viability in A549 cells and rat PDL fibroblasts exposed to 5%, 10% or 15% (v/v) CSE. Activation of caspase-3 in fetal lung connective tissue and alveolar epithelial cells may be one of the reasons for the developmental pulmonary toxicity induced by CSE.

Exposure cigarette smoke (CS) during prenatal life is the leading cause of preventable premature death. In this study, we explored the hypothesis that in vitro exposure of fetal lung cells to cigarette smoke extract (CSE) may result in the alteration of apoptosis through activation of caspase-3. Alongside we compared the responses of fetal lung cells with A549 cells and rat periodontal ligament (PDL) fibroblasts exposed to CSE in a dose dependent manner. Caspase-3 activity and inhibition was measured using a fluorometric assay. Cell viability in smoke exposed cells was measured using MTT formazan assay. Caspase-3 expression and cellular localization was detected by western blot analysis and immunofluorescence. Our results indicate that caspase-3 activity was significantly (p < 0.05) elevated and cell viability was significantly inhibited in fetal rat lung cells exposed to 10% or 15 % (v/v) CSE. No significant differences were observed in the caspase-3 activity or cellular viability in A549 cells and rat PDL fibroblasts exposed to 5%, 10% or 15% (v/v) CSE. Activation of caspase-3 in fetal lung connective tissue and alveolar epithelial cells may be one of the reasons for the developmental pulmonary toxicity induced by CSE.

Monocytes exhibiting a pro-inflammatory phenotype play a key role in adhesion and development of atherosclerotic plaques. As an alternative to smoking, next-generation tobacco and nicotine products (NGP) are now widely used. However, little is known about their pro-inflammatory effects on monocytes. We investigated cell viability, anti-oxidant and pro-inflammatory gene and protein expression in THP-1 monocytes after exposure to aqueous smoke extracts (AqE) of a heated tobacco product (HTP), an electronic cigarette (e-cig), a conventional cigarette (3R4F) and pure nicotine (nic). Treatment with 3R4F reduced cell viability in a dose-dependent manner, whereas exposure to alternative smoking products showed no difference to control. At the highest non-lethal dose of 3R4F (20%), the following notable mRNA expression changes were observed for 3R4F, HTP, and e-cig respectively, relative to control; HMOX1 (6-fold, < 2-fold, < 2-fold), NQO1 (3.5-fold, < 2-fold, < 2-fold), CCL2 (4-fold, 3.5-fold, 2.5-fold), IL1B (4-fold, 3-fold, < 2-fold), IL8 (5-fold, 2-fold, 2-fold), TNF (2-fold, 2-fold, < 2-fold) and ICAM1 was below the 2-fold threshold for all products. With respect to protein expression, IL1B (3-fold, < 2-fold, < 2-fold) and IL8 (3.5-fold, 2-fold, 2-fold) were elevated over the 2-fold threshold, whereas CCL2, TNF, and ICAM1 were below 2-fold expression for all products. At higher doses, greater inductions were observed with all extracts; however, NGP responses were typically lower than 3R4F. In conclusion, anti-oxidative and pro-inflammatory processes were activated by all products. NGPs overall showed lower responses relative to controls than THP-1 cells exposed to 3R4F AqE.