Lysophospholipid Acyltransferase 9 Promotes Emphysema Formation via Platelet-activating Factor.

Cigarette smoking is known to be the leading cause of chronic obstructive pulmonary disease (COPD). However, the detailed mechanisms have not been elucidated. PAF (platelet-activating factor), a potent inflammatory mediator, is involved in the pathogenesis of various respiratory diseases such as bronchial asthma and COPD. We focused on LPLAT9 (lysophospholipid acyltransferase 9), a biosynthetic enzyme of PAF, in the pathogenesis of COPD. LPLAT9 gene expression was observed in excised COPD lungs and single-cell RNA sequencing data of alveolar macrophages (AMs). LPLAT9 was predominant and upregulated in AMs, particularly monocyte-derived AMs, in patients with COPD. To identify the function of LPLAT9/PAF in AMs in the pathogenesis of COPD, we exposed systemic LPLAT9-knockout (LPALT9-/-) mice to cigarette smoke (CS). CS increased the number of AMs, especially the monocyte-derived fraction, which secreted MMP12 (matrix metalloprotease 12). Also, CS augmented LPLAT9 phosphorylation/activation on macrophages and, subsequently, PAF synthesis in the lung. The LPLAT9-/- mouse lung showed reduced PAF production after CS exposure. Intratracheal PAF administration accumulated AMs by increasing MCP1 (monocyte chemoattractant protein-1). After CS exposure, AM accumulation and subsequent pulmonary emphysema, a primary pathologic change of COPD, were reduced in LPALT9-/- mice compared with LPLAT9+/+ mice. Notably, these phenotypes were again worsened by LPLAT9+/+ bone marrow transplantation in LPALT9-/- mice. Thus, CS-induced LPLAT9 activation in monocyte-derived AMs aggravated pulmonary emphysema via PAF-induced further accumulation of AMs. These results suggest that PAF synthesized by LPLAT9 has an important role in the pathogenesis of COPD.

Cigarette smoke induces the ROS accumulation and iNOS activation through deactivation of Nrf-2/SIRT3 axis to mediate the human bronchial epithelium ferroptosis.

Cigarette smoke (CS)-induced oxidative stress drives the pathogenesis of respiratory diseases, in which the activation and accumulation of reactive oxygen species (ROS) play an important role. Ferroptosis, a regulated cell death induced by Fe2+-dependent, lipid peroxidation, and ROS, is closely related to CS-induced airway injury disease, but its mechanism remains unclear. We found that bronchial epithelial ferroptosis and expression of iNOS in smoking patients were significantly higher than that in non-smokers. The iNOS, induced by CS exposure, was involved in bronchial epithelial cell ferroptosis, whereas genetic depletion or pharmacologic inactivation of iNOS attenuated the CS-induced ferroptosis and mitochondrial dysfunction. Our mechanistic studies found that SIRT3 directly bound to and negatively regulated iNOS to mediate ferroptosis. Moreover, we found that the Nrf-2/SIRT3 signal was deactivated by cigarette smoke extract (CSE)-induced ROS. Collectively, these results linked CS to human bronchial epithelial cell ferroptosis through ROS deactivation of the Nrf-2/SIRT3 signal to promote iNOS expression. Our study provides new insights into the pathogenesis of CS-induced tracheal injury diseases such as chronic bronchitis, emphysema, and chronic obstructive pulmonary disease.

Mass Spectrometry Analysis of DNA and Protein Adducts as Biomarkers in Human Exposure to Cigarette Smoking: Acrolein as an Example.

Acrolein is a major component in cigarette smoke and a product of endogenous lipid peroxidation. It is difficult to distinguish human exposure to acrolein from exogenous sources versus endogenous causes, as components in cigarette smoke can stimulate lipid peroxidation in vivo. Therefore, analysis of acrolein-induced DNA and protein adducts by the highly accurate, sensitive, and specific mass spectrometry-based methods is vital to estimate the degree of damage by this IARC Group 2A carcinogen. This Perspective reviews the analyses of acrolein-induced DNA and protein adducts in humans by mass spectrometry focusing on samples accessible for biomonitoring, including DNA from leukocytes and oral cells and abundant proteins from blood, i.e., hemoglobin and serum albumin.

The development of cigarette smoke induced chronic pancreatitis in mice is associated with increased expression of K-Ras and NF-κB.

INTRODUCTION AND OBJECTIVE: Epidemiological studies have demonstrated a strong association between cigarette smoking (CS) and chronic pancreatitis (CP); however, the exact mechanisms of this phenomenon remains unknown. The authors have previously shown that increased Ras expression activates the NF-κB mediated pathway and promotes development of CP. However, it is unclear whether a similar phenomenon occurs in CS-induced CP. Therefore, the aim of the study was to determine whether CS increases the expression of K-Ras, and promotes the development of CP in mice exposed to repeated episodes of acute pancreatitis (AP). MATERIAL AND METHODS: C57BL6/cmdb mice were exposed to CS or a sham treatment for 12 weeks. After one week of exposure, half of the animals from both groups were additionally subjected to repeated cerulein treatment (once a week, for 10 consecutive weeks) to mimic recurrent episodes of AP. Extension of pancreatic damage was determined histologically by H&E and Trichrome staining. The expression of K-Ras protein and downstream components (NF-κB, Cox-2, TGF-ß) was evaluated by immunohistochemistry. RESULTS: C57BL6/cmdb mice exposed to CS or cerulein alone did not develop any chronic pancreatic damage. However, concomitant treatment with both of these agents caused focal acinar atrophy, with slight intralobular and perivascular areas of fibrosis, and inflammatory cells infiltration resembling mild CP. Moreover, immunohistochemistry examinations revealed increased pancreatic expression of K-Ras and NF-κB only in mice treated both with CS and cerulein. CONCLUSIONS: CS promotes development of CP in mice exposed to repeated episodes of AP. This process may be, at least partially, related to increased expression of K-Ras and NF-κB protein.

Exosomes derived from adipose-derived stem cells alleviate cigarette smoke-induced lung inflammation and injury by inhibiting alveolar macrophages pyroptosis.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a frequently encountered disease condition in clinical practice mainly caused by cigarette smoke (CS). The aim of this study was to investigate the protective roles of human adipose-derived stem cells-derived exosomes (ADSCs-Exo) in CS-induced lung inflammation and injury and explore the underlying mechanism by discovering the effects of ADSCs-Exo on alveolar macrophages (AMs) pyroptosis. METHODS: ADSCs were isolated from human adipose tissues harvested from three healthy donors, and then ADSCs-Exo were isolated. In vivo, 24 age-matched male C57BL/6 mice were exposed to CS for 4 weeks, followed by intratracheal administration of ADSCs-Exo or phosphate buffered saline. In vitro, MH-S cells, derived from mouse AMs, were stimulated by 2% CS extract (CSE) for 24 h, followed by the treatment of ADSCs-Exo or phosphate buffered saline. Pulmonary inflammation was analyzed by detecting pro-inflammatory cells and mediators in the bronchoalveolar lavage fluid. Lung histology was assessed by hematoxylin and eosin staining. Mucus production was determined by Alcian blue-periodic acid-Schiff staining. The profile of AMs pyroptosis was evaluated by detecting the levels of pyroptosis-indicated proteins. The inflammatory response in AMs and the phagocytic activity of AMs were also investigated. RESULTS: In mice exposed to CS, the levels of pro-inflammatory cells and mediators were significantly increased, mucus production was markedly increased and lung architecture was obviously disrupted. AMs pyroptosis was elevated and AMs phagocytosis was inhibited. However, the administration of ADSCs-Exo greatly reversed these alterations caused by CS exposure. Consistently, in MH-S cells with CSE-induced properties modelling those found in COPD, the cellular inflammatory response was elevated, the pyroptotic activity was upregulated while the phagocytosis was decreased. Nonetheless, these abnormalities were remarkably alleviated by the treatment of ADSCs-Exo. CONCLUSIONS: ADSCs-Exo effectively attenuate CS-induced airway mucus overproduction, lung inflammation and injury by inhibiting AMs pyroptosis. Therefore, hADSCs-Exo may be a promising cell-free therapeutic candidate for CS-induced lung inflammation and injury.

The unfolded protein response and apoptotic regulation in the human placenta due to maternal cigarette smoking and pre-eclampsia.

Maternal cigarette smoking (CS) and pre-eclampsia (PE) alter placental function and expression of important proteins which maintain homeostasis. Two interlinked pathways of interest are the unfolded protein response (UPR) and apoptosis. The UPR is upregulated in the PE placenta, but no data is available on the effects of CS and how it correlates with apoptotic expression. Samples of human placental tissue from normotensive non-smokers (n = 8), women with PE (n = 8), and CS (n = 8) were analysed using immunohistochemistry for 3 UPR markers (phosphorylated PKR-like endoplasmic reticulum (ER) kinase (pPERK), inositol-requiring enzyme 1 (IRE1), activating transcription factor 6 (ATF6)), and an antibody microarray for 19 apoptotic and stress regulating markers. For the PE group compared to the normotensive group, staining for pPERK was increased in decidual tissue and villi, and for IRE1, the overall percentage of stained villi per field of view was increased. There were no differences in UPR expression comparing CS to controls. Of the apoptotic markers, only IκBα (Ser32/36), which is part of an inhibitory pathway, showed a significant decrease in the PE and CS groups compared to controls. These findings suggest UPR regulation is more evident in PE with a general increase in ER stress due to decreased inhibition of apoptosis as compared to CS for which UPR was not altered.

Cigarette smoke extract and heated tobacco products promote ferritin cleavage and iron accumulation in human corneal epithelial cells.

The cornea is directly exposed to cigarette smoke, and smoking is a risk factor for several corneal diseases including dry eye syndrome. Currently, heated tobacco products (HTPs) are widely used as substitutes for cigarette smoking around the world. In the present study, we investigated the molecular mechanism(s) leading to cellular injury induced by cigarette smoke extract (CSE) or HTPs. Exposure to CSE perturbed the formation of tight junctions, leading to an increase in cell volume, a decrease in transepithelial electrical resistance (TER) in the human corneal epithelial cell-transformed (HCE-T) cell line. Moreover, CSE exposure induced both lipid peroxidation and ferrous [Fe(II)] ion accumulation in autolysosomal compartments. Interestingly, a cleaved form of ferritin appeared when HCE-T cells were incubated with CSE. This aberrant ferritin processing was suppressed by treatment with autophagy inhibitors. Furthermore, the CSE-induced cell death was suppressed by either ferrostatin-1 or deferoxamine (DFO). CSE exposure also promoted the expression of cytokines whereas DFO treatment inhibited the CSE-induced expression of these cytokines. Exposure to HTPs also induced both HCE-T cell death and cleaved ferritin accumulation in a concentration- and time-dependent manner. These results indicated that CSE or HTPs activated the ferroptosis signaling pathway, which contributed to corneal epithelial cell injury.

Analysis of electric cigarette liquid effect on mouse brain tumor growth through EGFR and ERK activation.

INTRODUCTION: Recently, electric cigarettes with liquid (e-liquid) were introduced as an alternative to tobacco smoking. They were promoted as possible cessation aids and were considered to be potentially less harmful than traditional tobacco-based cigarettes. However, there is little information on the toxicants present in e-liquids and their possible carcinogenic effects. METHODS: Western blot analysis was performed to identify the protein levels of cancer progression related signal transducers. Patient-derived brain tumor cells (CSC2) were injected into mouse brains and tumor growth was then observed by performing magnetic resonance imaging (MRI) and hematoxylin and eosin (H&E) staining of the whole brain. Immunohistochemistry (IHC) staining and Immunofluorescence staining were performed to study the expression of pEGFR and pERK. RESULTS: Western blotting revealed that e-liquids increased pEGFR and pERK expression in a dose dependent manner. Animal experiments revealed that the e-liquid treated group had accelerated tumor growth and poor prognosis compared to the vehicle group. Histological staining showed activation of pEGFR and pERK in the e-liquid treated group. CONCLUSION: Our study revealed that e-liquid activates pEGFR and pERK, leading to accelerated brain tumor growth and poor prognosis.

Alterations in plasma hyaluronic acid in patients with clinically stable COPD versus (non)smoking controls.

Hyaluronic acid (HA) is a key component of the extracellular matrix. HA and its metabolism are suggested to be altered in the lungs of patients with chronic obstructive pulmonary disease (COPD). The present study explored systemic HA, and its metabolic regulators, in patients with clinically stable COPD and smoking and non-smoking controls. Furthermore, associations of HA with acute exacerbations (AECOPD), airway-related hospitalizations, systemic inflammation and cardiovascular risk were studied. In total, 192 patients with moderate to very severe COPD [aged 62.3 y (± SD 7.0)], 84 smoking controls [aged 61.8 y (± 5.7)], and 107 non-smoking controls [aged 60.1 y (± 7.0)] were included. Plasma HA was reduced in patients with COPD compared to non-smoking controls (p = 0.033), but was comparable after adjusting for age and sex. Expression of HAS-3 did not differ between groups, but was substantially less detectable in more patients with COPD than (non)smoking controls (p < 0.001). Expression of HYAL-2 was enhanced in patients with COPD versus smoking (p = 0.019) and non-smoking (p < 0.001) controls, also in the age- and sex- adjusted model (p < 0.001). Plasma HA was not associated with AECOPD, airway-related hospitalizations in the previous year, or systemic inflammation in COPD. Arterial pulse wave velocity explained some of the variance (< 10%) in plasma HA (p = 0.006). Overall, these results indicate that expression of HYAL-2, but not plasma HA nor HAS-3, is enhanced in patients with COPD compared to (non)smoking controls. Furthermore, HA was not associated with clinical outcomes, yet, cardiovascular risk might play a role in its systemic regulation in stable COPD.

Paradoxical effects of cigarette smoke and COPD on SARS-CoV-2 infection and disease.

BACKGROUND: How cigarette smoke (CS) and chronic obstructive pulmonary disease (COPD) affect severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection and severity is controversial. We investigated the effects of COPD and CS on the expression of SARS-CoV-2 entry receptor ACE2 in vivo in COPD patients and controls and in CS-exposed mice, and the effects of CS on SARS-CoV-2 infection in human bronchial epithelial cells in vitro. METHODS: We quantified: (1) pulmonary ACE2 protein levels by immunostaining and ELISA, and both ACE2 and/or TMPRSS2 mRNA levels by RT-qPCR in two independent human cohorts; and (2) pulmonary ACE2 protein levels by immunostaining and ELISA in C57BL/6 WT mice exposed to air or CS for up to 6 months. The effects of CS exposure on SARS-CoV-2 infection were evaluated after in vitro infection of Calu-3 cells and differentiated human bronchial epithelial cells (HBECs), respectively. RESULTS: ACE2 protein and mRNA levels were decreased in peripheral airways from COPD patients versus controls but similar in central airways. Mice exposed to CS had decreased ACE2 protein levels in their bronchial and alveolar epithelia versus air-exposed mice. CS treatment decreased viral replication in Calu-3 cells, as determined by immunofluorescence staining for replicative double-stranded RNA (dsRNA) and western blot for viral N protein. Acute CS exposure decreased in vitro SARS-CoV-2 replication in HBECs, as determined by plaque assay and RT-qPCR. CONCLUSIONS: ACE2 levels were decreased in both bronchial and alveolar epithelial cells from COPD patients versus controls, and from CS-exposed versus air-exposed mice. CS-pre-exposure potently inhibited SARS-CoV-2 replication in vitro. These findings urge to investigate further the controversial effects of CS and COPD on SARS-CoV-2 infection.

Smoking induces sex-specific changes in the small airway proteome.

INTRODUCTION: Cigarette smoke triggers many cellular and signaling responses in the lung and the resulting inflammation plays a central role in smoke-related lung diseases, such as COPD. We explored the effects of smoking on the small airway proteome in samples obtained by collection of exhaled particles with the aim to identify specific proteins dysregulated by smoking. METHODS: Exhaled particles were obtained from 38 current smokers, 47 former smokers and 22 healthy controls with the PExA method. 120 ng of sample was collected from individual subjects and analyzed with the SOMAscan proteomics platform. General linear model-based statistics were performed. RESULTS: Two hundred and three proteins were detected in at least half of 107 total samples. Active smoking exerted a significant impact on the protein composition of respiratory tract lining fluid (RTLF), with 81 proteins altered in current smokers compared to never smokers (p < 0.05, q < 0.124). Among the proteins most clearly discriminating between current and never smokers were sRAGE, FSTL3, SPOCK2 and protein S, all of them being less abundant in current smokers. Analysis stratified for sex unveiled sex differences with more pronounced proteomic alterations due to active smoking in females than males. Proteins whose abundance was altered by active smoking in women were to a larger extent related to the complement system. The small airway protein profile of former smokers appeared to be more similar to that observed in never smokers. CONCLUSIONS: The study shows that smoking has a strong impact on protein expression in the small airways, and that smoking affects men and women differently, suggesting PExA sampling combined with high sensitivity protein analysis offers a promising platform for early detection of COPD and identification of novel COPD drug targets.

Cigarette Smoke Specifically Affects Small Airway Epithelial Cell Populations and Triggers the Expansion of Inflammatory and Squamous Differentiation Associated Basal Cells.

Smoking is a major risk factor for chronic obstructive pulmonary disease (COPD) and causes remodeling of the small airways. However, the exact smoke-induced effects on the different types of small airway epithelial cells (SAECs) are poorly understood. Here, using air-liquid interface (ALI) cultures, single-cell RNA-sequencing reveals previously unrecognized transcriptional heterogeneity within the small airway epithelium and cell type-specific effects upon acute and chronic cigarette smoke exposure. Smoke triggers detoxification and inflammatory responses and aberrantly activates and alters basal cell differentiation. This results in an increase of inflammatory basal-to-secretory cell intermediates and, particularly after chronic smoke exposure, a massive expansion of a rare inflammatory and squamous metaplasia associated KRT6A+ basal cell state and an altered secretory cell landscape. ALI cultures originating from healthy non-smokers and COPD smokers show similar responses to cigarette smoke exposure, although an increased pro-inflammatory profile is conserved in the latter. Taken together, the in vitro models provide high-resolution insights into the smoke-induced remodeling of the small airways resembling the pathological processes in COPD airways. The data may also help to better understand other lung diseases including COVID-19, as the data reflect the smoke-dependent variable induction of SARS-CoV-2 entry factors across SAEC populations.

Population Pharmacokinetics of Olanzapine and Samidorphan When Administered in Combination in Healthy Subjects and Patients With Schizophrenia.

A combination of olanzapine and samidorphan was recently approved by the US Food and Drug Administration for the treatment of patients with schizophrenia or bipolar I disorder. Population pharmacokinetic models for olanzapine and samidorphan were developed using data from 11 clinical studies in healthy subjects or patients with schizophrenia. A 2-compartment disposition model with first-order absorption and elimination and a lag time for absorption adequately described concentration-time profiles of both olanzapine and samidorphan. Age, sex, race, smoking status, and body weight were identified as covariates that impacted the pharmacokinetics of olanzapine. A moderate effect of body weight on samidorphan pharmacokinetics was identified by the model but was not considered clinically meaningful. The effects of food, hepatic or renal impairment, and coadministration with rifampin on the pharmacokinetics of olanzapine and samidorphan, as estimated by the population pharmacokinetic analysis, were consistent with findings from dedicated clinical studies designed to evaluate these specific covariates of interest. Food intake did not have a clinically relevant effect on the pharmacokinetics of olanzapine or samidorphan. Consistent with the known metabolic pathways for olanzapine (primarily via uridine 5'-diphospho-glucuronosyltransferase-mediated direct glucuronidation and cytochrome P450 [CYP]-mediated oxidation) and for samidorphan (predominantly mediated by CYP3A4), coadministration of olanzapine and samidorphan with rifampin, a strong inducer of CYP3A4 and an inducer of uridine 5'-diphospho-glucuronosyltransferase enzymes, significantly decreased the systemic exposure of both olanzapine and samidorphan. Severe renal impairment or moderate hepatic impairment resulted in a modest increase in olanzapine and samidorphan exposure.

GABA concentrations in the anterior cingulate and dorsolateral prefrontal cortices: Associations with chronic cigarette smoking, neurocognition, and decision making.

Chronic cigarette smoking is associated with regional metabolite abnormalities in choline-containing compounds, creatine-containing compounds, glutamate, and N-acetylaspartate. The effects of cigarette smoking on anterior frontal cortical gamma-aminobutyric acid (GABA) concentration are unknown. This study compared chronic smokers (n = 33) and nonsmokers (n = 31) on anterior cingulate cortex (ACC) and right dorsolateral prefrontal cortex (DLPFC) GABA+ (the sum of GABA and coedited macromolecules) concentrations and associations of GABA+ levels in these regions with seven neurocognitive domains of functioning, decision making, and impulsivity measures. Smokers had significantly lower right DLPFC GABA+ concentration than nonsmokers, but groups were equivalent on ACC GABA+ level. Across groups, greater number of days since end of menstrual cycle was related to higher GABA+ level in the ACC but not right DLPFC GABA+ concentration. In exploratory correlation analyses, higher ACC and right DLPFC GABA+ levels were associated with faster processing speed and better auditory-verbal memory, respectively, in the combined group of smokers and nonsmokers; in smokers only, higher ACC GABA+ was related to better decision making and auditory-verbal learning. This study contributes additional novel data on the adverse effects of chronic cigarette smoking on the adult human brain and demonstrated ACC and DLPFC GABA+ concentrations were associated with neurocognition and decision making/impulsivity in active cigarette smokers. Longitudinal studies on the effects of smoking cessation on regional brain GABA levels, with a greater number of female participants, are required to determine if the observed metabolite abnormalities are persistent or normalize with smoking cessation.

miRNA-138-5p suppresses cigarette smoke-induced apoptosis in testicular cells by targeting Caspase-3 through the Bcl-2 signaling pathway.

Long-term cigarette smoking (CS) can cause testicular toxicity, which interferes with normal spermatogenesis and leads to male infertility. One possible mechanism for this is the activation of the apoptosis signaling pathway, which leads to the irreversible apoptosis of testicular cells. However, the exact mechanism for this is not completely understood. Cell viability, cell apoptosis, and lactate dehydrogenase release assays were performed to elucidate the function of micro RNA (miRNA) in the pathogenesis of male testicular cell injury induced by CS. The results suggested that testicular cell injury was associated with CS both in vitro and in vivo. CS extract (CSE)-treated Leydig and Sertoli cells showed noticeable apoptosis. Based on the results of Agilent miRNA microarray and bioinformatics analyses, miRNA-138-5p was used in subsequent experiments. Quantitative polymerase chain reaction and Western blot assays showed a negative correlation between miR-138-5p and Caspase-3 expression. Transfection of miR-138-5p mimic significantly inhibited apoptosis and downregulated the expression of Caspase-3 in TM3 and TM4 cells. Furthermore, a dual-luciferase reporter assay demonstrated that miR-138-5p directly targeted Caspase-3 to regulate the apoptosis of testicular cells mediated by CSE. In addition, overexpression of miR-138-5p markedly downregulated the expression of p53 and Bak, which played critical roles in the Bcl-2 pathway. These results demonstrate that miRNA-138-5p inhibits CS-induced apoptosis in testicular cells by targeting Caspase-3 through the Bcl-2 signaling pathway.

Structural and functional remodeling of the female Apoe-/- mouse aorta due to chronic cigarette smoke exposure.

Despite a decline in popularity over the past several decades, cigarette smoking remains a leading cause of cardiovascular morbidity and mortality. Yet, the effects of cigarette smoking on vascular structure and function are largely unknown. To evaluate changes in the mechanical properties of the aorta that occur with chronic smoking, we exposed female apolipoprotein E-deficient mice to mainstream cigarette smoke daily for 24 wk, with room air as control. By the time of euthanasia, cigarette-exposed mice had lower body mass but experienced larger systolic/diastolic blood pressure when compared with controls. Smoking was associated with significant wall thickening, reduced axial stretch, and circumferential material softening of the aorta. Although this contributed to maintaining intrinsic tissue stiffness at control levels despite larger pressure loads, the structural stiffness became significantly larger. Furthermore, the aorta from cigarette-exposed mice exhibited decreased ability to store elastic energy and augment diastolic blood flow. Histological analysis revealed a region-dependent increase in the cross-sectional area due to smoking. Increased smooth muscle and extracellular matrix content led to medial thickening in the ascending aorta, whereas collagen deposition increased the thickness of the descending thoracic and abdominal aorta. Atherosclerotic lesions were larger in exposed vessels and featured a necrotic core overlaid by a thinned fibrous cap and macrophage infiltration, consistent with a vulnerable phenotype. Collectively, our data indicate that cigarette smoking decreases the mechanical functionality of the aorta, inflicts morphometric alterations to distinct segments of the aorta, and accelerates the progression of atherosclerosis.NEW & NOTEWORTHY We studied the effects of chronic cigarette smoking on the structure and function of the aorta in a mouse model of nose-only aerosol inhalation. Our data indicated that exposure to cigarette smoke impairs vascular function by reducing the ability of the aorta to store elastic energy and by decreasing aortic distensibility. Combined with a more vulnerable atherosclerotic phenotype, these findings reveal the biomechanical mechanisms that support the development of cardiovascular disease due to cigarette smoking.

Eurotium cristatum Fermented Loose Dark Tea Ameliorates Cigarette Smoke-Induced Lung Injury by MAPK Pathway and Enhances Hepatic Metabolic Detoxification by PXR/AhR Pathway in Mice.

Cigarette smoke- (CS-) induced oxidative stress and inflammation in the lung are serious health problems. Primary and reprocessed tea products contain multiple antioxidants that have been reported to protect the lung against CS-induced injury. However, the beneficial effects of Eurotium cristatum fermented loose dark tea (ECT) and Eurotium cristatum particle metabolites (ECP) on CS-induced lung injury and its potential hepatic metabolic detoxification are still unclear. Therefore, sixty mice were randomly divided into six equal groups. CS-exposed mice were prevented or treated with ECP or ECT infusions for 12 or 8 weeks to determine the antioxidative stress, anti-inflammatory and potential metabolic detoxification of ECT and ECP. Thirty-six mice were randomly divided into six equal groups to observe the effects on hepatic metabolic detoxification by replacing daily drinking water with ECT. Results showed that CS significantly decreased the activities of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) and upregulated the expressions of malondialdehyde (MDA), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), IL-8, and IL-1ß in serum. These adverse effects were modulated by ECP and ECT. In addition, ECT upregulated the mRNA expression of pregnane X receptor (PXR) and cytochrome P450 (CYP450) in the liver on daily free drinking ECT mice group. Western blot analysis further revealed that in CS-exposed mice, ECP and ECT significantly decreased the phosphorylation of mitogen-activated protein kinase (MAPK) in the lung but upregulated the protein expressions of PXR and aryl hydrocarbon receptor (AhR) in the liver. Overall, our findings demonstrated that ECT and ECP protected against lung injury induced by CS via MAPK pathway and enhanced hepatic metabolic detoxification via PXR and AhR pathways. Therefore, daily intake of ECT and ECP can potentially protect against CS-induced oxidative and inflammatory injuries.

The effect of long-term doxycycline treatment in a mouse model of cigarette smoke-induced emphysema and pulmonary hypertension.

Chronic obstructive pulmonary disease (COPD) is a major cause of death and a still incurable disease, comprising emphysema and chronic bronchitis. In addition to airflow limitation, patients with COPD can suffer from pulmonary hypertension (PH). Doxycycline, an antibiotic from the tetracycline family, in addition to its pronounced antimicrobial activity, acts as a matrix metalloproteinase (MMP) inhibitor and has anti-inflammatory properties. Furthermore, doxycycline treatment exhibited a beneficial effect in several preclinical cardiovascular disease models. In preclinical research, doxycycline is frequently employed for gene expression modulation in Tet-On/Tet-Off transgenic animal models. Therefore, it is crucial to know whether doxycycline treatment in Tet-On/Tet-Off systems has effects independent of gene expression modulation by such systems. Against this background, we assessed the possible curative effects of long-term doxycycline administration in a mouse model of chronic CS exposure. Animals were exposed to cigarette smoke (CS) for 8 mo and then subsequently treated with doxycycline for additional 3 mo in room air conditions. Doxycycline decreased the expression of MMPs and general pro-inflammatory markers in the lungs from CS-exposed mice. This downregulation was, however, insufficient to ameliorate CS-induced emphysema or PH. Tet-On/Tet-Off induction by doxycycline in such models is a feasible genetic approach to study curative effects at least in established CS-induced emphysema and PH. However, we report several parameters that are influenced by doxycycline and use of a Tet-On/Tet-Off system when evaluating those parameters should be interpreted with caution.

Plasma Brain-Derived Neurotropic Factor Levels Are Associated with Aging and Smoking But Not with Future Dementia in the Rotterdam Study.

BACKGROUND: Brain-derived neurotropic factor (BDNF) plays a vital role in neuronal survival and plasticity and facilitates long-term potentiation, essential for memory. Alterations in BDNF signaling have been associated with cognitive impairment, dementia, and Alzheimer's disease. Although peripheral BDNF levels are reduced in dementia patients, it is unclear whether changes in BDNF levels precede or follow dementia onset. OBJECTIVE: In the present study, we examined the association between BDNF plasma levels and dementia risk over a follow-up period of up to 16 years. METHODS: Plasma BDNF levels were assessed in 758 participants of the Rotterdam Study. Dementia was assessed from baseline (1997-1999) to follow-up until January 2016. Associations of plasma BDNF and incident dementia were assessed with Cox proportional hazards models, adjusted for age and sex. Associations between plasma BDNF and lifestyle and metabolic factors are investigated using linear regression. RESULTS: During a follow up of 3,286 person-years, 131 participants developed dementia, of whom 104 had Alzheimer's disease. We did not find an association between plasma BDNF and risk of dementia (adjusted hazard ratio 0.99; 95%CI 0.84-1.16). BDNF levels were positively associated with age (B = 0.003, SD = 0.001, p = 0.002), smoking (B = 0.08, SE = 0.01, p = < 0.001), and female sex (B = 0.03, SE = 0.01, p = 0.03), but not with physical activity level (B = -0.01, SE = 0.01, p = 0.06). CONCLUSION: The findings suggest that peripheral BDNF levels are not associated with an increased risk of dementia.

Application of text mining to develop AOP-based mucus hypersecretion genesets and confirmation with in vitro and clinical samples.

Mucus hypersecretion contributes to lung function impairment observed in COPD (chronic obstructive pulmonary disease), a tobacco smoking-related disease. A detailed mucus hypersecretion adverse outcome pathway (AOP) has been constructed from literature reviews, experimental and clinical data, mapping key events (KEs) across biological organisational hierarchy leading to an adverse outcome. AOPs can guide the development of biomarkers that are potentially predictive of diseases and support the assessment frameworks of nicotine products including electronic cigarettes. Here, we describe a method employing manual literature curation supported by a focused automated text mining approach to identify genes involved in 5 KEs contributing to decreased lung function observed in tobacco-related COPD. KE genesets were subsequently confirmed by unsupervised clustering against 3 different transcriptomic datasets including (1) in vitro acute cigarette smoke and e-cigarette aerosol exposure, (2) in vitro repeated incubation with IL-13, and (3) lung biopsies from COPD and healthy patients. The 5 KE genesets were demonstrated to be predictive of cigarette smoke exposure and mucus hypersecretion in vitro, and less conclusively predict the COPD status of lung biopsies. In conclusion, using a focused automated text mining and curation approach with experimental and clinical data supports the development of risk assessment strategies utilising AOPs.