A study of 9 common breath VOCs in 504 healthy subjects using PTR-TOF-MS.

INTRODUCTION: This study employs Proton-Transfer-Reaction Mass Spectrometry (PTR-MS) to analyze exhaled breath profiles of 504 healthy adults, focusing on nine common volatile organic compounds (VOCs): acetone, acetaldehyde, acetonitrile, ethanol, isoprene, methanol, propanol, phenol, and toluene. PTR-MS offers real-time VOC measurement, crucial for understanding breath biomarkers and their applications in health assessment. OBJECTIVES: The study aims to investigate how demographic factors-gender, age, and smoking history-affect VOC concentrations in exhaled breath. The objective is to enhance our understanding of breath biomarkers and their potential for health monitoring and clinical diagnosis. METHODS: Exhaled breath samples were collected using PTR-MS, measuring concentrations of nine VOCs. The data were analyzed to discern distribution patterns across demographic groups. RESULTS: Males showed higher average VOC levels for certain compounds. Propanol and methanol concentrations significantly increased with age. Smoking history influenced VOC levels, with differences among non-smokers, current smokers, and ex-smokers. CONCLUSION: This research provides valuable insights into demographic influences on exhaled VOC profiles, emphasizing the potential of breath analysis for health assessment. PTR-MS's real-time measurement capabilities are crucial for capturing dynamic VOC changes, offering advantages over conventional methods. These findings lay a foundation for advancements in non-invasive disease detection, highlighting the importance of considering demographics in breath biomarker research.

Heavy metals in cigarette smoke strongly inhibit pancreatic ductal function and promote development of chronic pancreatitis.

BACKGROUND AND AIMS: Smoking is recognised as an independent risk factor in the development of chronic pancreatitis (CP). Cystic fibrosis transmembrane conductance regulator (CFTR) function and ductal fluid and bicarbonate secretion are also known to be impaired in CP, so it is crucial to understand the relationships between smoking, pancreatic ductal function and the development of CP. METHODS: We measured sweat chloride (Cl-) concentrations in patients with and without CP, both smokers and non-smokers, to assess CFTR activity. Serum heavy metal levels and tissue cadmium concentrations were determined by mass spectrometry in smoking and non-smoking patients. Guinea pigs were exposed to cigarette smoke, and cigarette smoke extract (CSE) was prepared to characterise its effects on pancreatic HCO3 - and fluid secretion and CFTR function. We administered cerulein to both the smoking and non-smoking groups of mice to induce pancreatitis. RESULTS: Sweat samples from smokers, both with and without CP, exhibited elevated Cl- concentrations compared to those from non-smokers, indicating a decrease in CFTR activity due to smoking. Pancreatic tissues from smokers, regardless of CP status, displayed lower CFTR expression than those from non-smokers. Serum levels of cadmium and mercury, as well as pancreatic tissue cadmium, were increased in smokers. Smoking, CSE, cadmium, mercury and nicotine all hindered fluid and HCO3 - secretion and CFTR activity in pancreatic ductal cells. These effects were mediated by sustained increases in intracellular calcium ([Ca2+]i), depletion of intracellular ATP (ATPi) and mitochondrial membrane depolarisation. CONCLUSION: Smoking impairs pancreatic ductal function and contributes to the development of CP. Heavy metals, notably cadmium, play a significant role in the harmful effects of smoking. KEY POINTS: Smoking and cigarette smoke extract diminish pancreatic ductal fluid and HCO3 - secretion as well as the expression and function of CFTR Cd and Hg concentrations are significantly higher in the serum samples of smokers Cd accumulates in the pancreatic tissue of smokers.

Roles of glutamic pyruvate transaminase 2 in reprogramming of airway epithelial lipidomic and metabolomic profiles after smoking.

Metabolic abnormalities represent one of the pathological features of chronic obstructive pulmonary disease (COPD). Glutamic pyruvate transaminase 2 (GPT2) is involved in glutamate metabolism and lipid synthesis pathways, whilst the exact roles of GPT2 in the occurrence and development of COPD remains uncertain. This study aims at investigating how GPT2 and the associated genes modulate smoking-induced airway epithelial metabolism and damage by reprogramming lipid synthesis. The circulating or human airway epithelial metabolomic and lipidomic profiles of COPD patients or cell-lines explored with smoking were assessed to elucidate the pivotal roles of GPT2 in reprogramming processes. We found that GPT2 regulate the reprogramming of lipid metabolisms caused by smoking, especially phosphatidylcholine (PC) and triacylglycerol (TAG), along with changes in the expression of lipid metabolism-associated genes. GPT2 modulated cell sensitivities and survival in response to smoking by enhancing mitochondrial functions and maintaining lipid and energy homeostasis. Our findings provide evidence for the involvement of GPT2 in the reprogramming of airway epithelial lipids following smoking, as well as the molecular mechanisms underlying GPT2-mediated regulation, which may offer an alternative of therapeutic strategies for chronic lung diseases.

Smoking primes the metabolomic response in trauma.

INTRODUCTION: Smoking is a public health threat because of its well-described link to increased oxidative stress-related diseases including peripheral vascular disease and coronary artery disease. Tobacco use has been linked to risk of inpatient trauma morbidity including acute respiratory distress syndrome; however, its mechanistic effect on comprehensive metabolic heterogeneity has yet to be examined. METHODS: Plasma was obtained on arrival from injured patients at a Level 1 trauma center and analyzed with modern mass spectrometry-based metabolomics. Patients were stratified by nonsmoker, passive smoker, and active smoker by lower, interquartile, and upper quartile ranges of cotinine intensity peaks. Patients were substratified by high injury/high shock (Injury Severity Score, ≥15; base excess, <-6) and compared with healthy controls. p Value of <0.05 following false discovery rate correction of t test was considered significant. RESULTS: Forty-eight patients with high injury/high shock (7 nonsmokers [15%], 25 passive smokers [52%], and 16 active smokers [33%]) and 95 healthy patients who served as controls (30 nonsmokers [32%], 43 passive smokers [45%], and 22 active smokers [23%]) were included. Elevated metabolites in our controls who were active smokers include enrichment in chronic inflammatory and oxidative processes. Elevated metabolites in active smokers in high injury/high shock include enrichment in the malate-aspartate shuttle, tyrosine metabolism, carnitine synthesis, and oxidation of very long-chain fatty acids. CONCLUSION: Smoking promotes a state of oxidative stress leading to mitochondrial dysfunction, which is additive to the inflammatory milieu of trauma. Smoking is associated with impaired mitochondrial substrate utilization of long-chain fatty acids, aspartate, and tyrosine, all of which accentuate oxidative stress following injury. This altered expression represents an ideal target for therapies to reduce oxidative damage toward the goal of personalized treatment of trauma patients. LEVEL OF EVIDENCE: Prognostic and Epidemiological; Level IV.

Quantification of Heavy Metals in the Nasal Turbines of Smokers and Nonsmokers.

OBJECTIVES: Cigarette smoke is known to contain toxic heavy metals. In this study, heavy metal levels in the nasal turbinate tissues of smokers and nonsmokers were measured and compared with Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). METHODS: Forty patients who come to the Otorhinolaryngology outpatient clinic due to nasal obstruction and are given an appointment for partial turbinate reduction operation due to inferior turbinate hypertrophy, according to their smoking status, were divided into two groups: those who had smoked one pack/day for at least 10 years and those who had never smoked. The levels of heavy metals (Al, As, Ba, Cd, Cr, Co, Cu, Pb, Mn, Hg, Ni, Se, and Ag) were compared by ICP-MS in nasal turbinate tissues. RESULTS: Al (p = 0.002), Cr (p < 0.001), Co (p < 0.001), Ni (p = 0.001), Cu (p < 0.001), As (p < 0.001), Se (p < 0.001), Ag (p < 0.001), Cd (p = 0.001), Ba (p = 0.008), Hg (p < 0.001), and Pb (p < 0.001) values in the smoker group were found to be significantly higher than the values of nonsmokers. Although the Mn level was high in smokers, no significant difference was observed (p = 0.299). CONCLUSIONS: Smoking can cause nasal and sinus problems. In this study, we observed that the smoking group had significantly higher levels of almost all the heavy metals investigated in the nasal turbinate tissues. As smoking damages, the mucociliary system and the mucosa, heavy metals from cigarettes may accumulate further and cause harm to the nasal tissues. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:3562-3567, 2024.

Quantitative profiling and baseline intervals of trace elements in healthy lung tissues.

BACKGROUND: Human lung tissue, as an interface with the environment, is susceptible to various environmental pollutants, including trace metals. However, quantitative data on trace metals in human lung tissues remain poorly described. METHODS: This study aimed to characterize the elemental composition of histologically healthy, unaffected parts of human lung tissues, associated with non-infective, non-infiltrative, and non-malignant diseases (n = 60) for essential (Cr, Mn, Fe, Co, Cu, Zn, and Se) and toxic trace elements (Sr, Ni, As, Cd, and Pb). Additionally, we investigated the influence of personal factors (sex, age, and smoking habits) on the examined trace element profiles, as well as between the trace elements correlations in the healthy human lungs. RESULTS: Among the analyzed trace elements, Fe was the most prevalent, while As was the least prevalent in healthy lung tissues. Stratifying by age revealed significantly higher Cr and Co (less Sr, Ni, and Pb) and lower Se levels in older individuals (above 65 years) compared to their younger counterparts. Sex-based differences were also notable, with Cu and Co 1.2- and 2.3-fold higher levels in females than in males. Exploring the impact of smoking habits revealed a striking 10-fold increase in Cd levels in the lung tissues of smokers compared to non-smokers. Correlation analyses showed significant positive associations between concentrations of certain toxic and essential trace elements in healthy lung tissues. CONCLUSIONS: This study could contribute to the establishment of baseline intervals for essential and toxic trace elements, valuable for toxicological and clinical assessment, in healthy, unaffected human lungs, and indicates the influence of sex, age, and smoking. However, further larger-scale studies are needed to make more stable conclusions.

Lower Dorsal Putamen D2/3 Receptor Availability and Amphetamine-Induced Dopamine Release are Related to Poorer Cognitive Function in Recently Abstinent People Who Smoke and Healthy Controls.

INTRODUCTION: In the dopamine system, the mesolimbic pathway, including the dorsal striatum, underlies the reinforcing properties of tobacco smoking, and the mesocortical pathway, including the dorsolateral prefrontal cortex (dlPFC), is critical for cognitive functioning. Dysregulated dopamine signaling has been linked to drug-seeking behaviors and cognitive deficits. The dorsal striatum and dlPFC are structurally and functionally connected and are key regions for cognitive functioning. We recently showed that people who smoke have lower dlPFC dopamine (D2/3R) receptor availability than people who do not, which is related to poorer cognitive function. AIMS AND METHODS: The goal of this study was to examine the same brain-behavior relationship in the dorsal striatum. Twenty-nine (18 males) recently abstinent people who smoke and 29 sex-matched healthy controls participated in 2 same-day [11C]-(+)-PHNO positron emission tomography scans before and after amphetamine administration to provoke dopamine release. D2/3R availability (binding potential; BPND) and amphetamine-induced dopamine release (%ΔBPND) were calculated. Cognition (verbal learning and memory) was assessed with the CogState computerized battery. RESULTS: There were no group differences in baseline BPND. People who smoke have a smaller magnitude %ΔBPND in dorsal putamen than healthy controls (p = .022). People who smoke perform worse on immediate (p = .035) and delayed (p = .011) recall than healthy controls. In all people, lower dorsal putamen BPND was associated with worse immediate (p = .006) and delayed recall (p = .049), and lower %ΔBPND was related to worse delayed recall (p = .022). CONCLUSIONS: Lower dorsal putamen D2/3R availability and function are associated with disruptions in cognitive function that may underlie difficulty with resisting smoking. IMPLICATIONS: This study directly relates dopamine imaging outcomes in the dorsal striatum to cognitive function in recently abstinent people who smoke cigarettes and healthy controls. The current work included a well-characterized subject sample in terms of demographics, smoking characteristics, and a validated neurocognitive test of verbal learning and memory. The findings of this study extend previous literature relating dopamine imaging outcomes to cognition in recently abstinent people who smoke and people who do not smoke, expanding our understanding of brain-behavior relationships.

Dual-Function Platform Based on Postsynthetic Functionalization of a Water-Stable Hydrogen-Bonded Organic Framework: Ratiometric Sensing of Nicotine and Cotinine and Dynamic Anticounterfeiting for Information Encryption.

Nicotine and its major metabolite cotinine are widely used as markers of tobacco smoke abstinence as well as indicators of active smoking levels and the assessment of passive inhalation of tobacco smoke in nonsmokers. Therefore, using an easy-to-prepare sensing platform that can provide a rapid, highly sensitive response for the simultaneous detection of salivary nicotine levels and urinary cotinine levels is especially crucial for helping heavy cigarette smokers quit smoking and protecting public health. Hydrogen-bonded organic frameworks, as a novel class of porous crystalline materials, show immense potential for functional modification and optical sensing. Herein, a new HOF was prepared by a simple solvent evaporation method, and a dual-emitting material Eu(bpy)@HOF-215(1) was obtained by the postsynthetic modification of HOF by lanthanide luminescent complexes, which maintains favorable structural stability and introduces the characteristic emitting of Eu, allowing use as a ratiometric fluorescent sensor for salivary nicotine and urinary cotinine, with a limit of detection of nicotine of 0.045 µM in saliva and a limit of detection of cotinine of 0.591 µM in urine. Furthermore, luminescent inks based on HOF-215 have been fabricated based on the photoresponse variations of 1 to NIC and COT, which enables the multilevel encryption and decryption of information, in a dynamic and recyclable process. This work not only synthesizes a novel blue HOF but also provides a representative successful case of a dual-function platform for simultaneous application to ratiometric sensing and dynamic anticounterfeiting.

Serial Sampling of the Small Airway Epithelium to Identify Persistent Smoking-dysregulated Genes.

Rationale: The small airway epithelium (beyond the sixth generation), the initiation site of smoking-induced airway disorders, is highly sensitive to the stress of smoking. Because of variations over time in smoking habits, the small airway epithelium transcriptome is dynamic, fluctuating not only among smokers but also within each smoker. Objectives: To perform accurate assessment of the smoking-related dysregulation of the human small airway epithelium despite the variation of smoking within the same individual and of the effects of smoking cessation on the dysregulated transcriptome. Methods: We conducted serial sampling of the same smokers and nonsmoker control subjects over time to identify persistent smoking dysregulation of the biology of the small airway epithelium over 1 year. We conducted serial sampling of smokers who quit smoking, before and after smoking cessation, to assess the effect of smoking cessation on the smoking-dysregulated genes. Measurements and Main Results: Repeated measures ANOVA of the small airway epithelium transcriptome sampled four times in the same individuals over 1 year enabled the identification of 475 persistent smoking-dysregulated genes. Most genes were normalized after 12 months of smoking cessation; however, 53 (11%) genes, including CYP1B1, PIR, ME1, and TRIM16, remained persistently abnormally expressed. Dysregulated pathways enriched with the nonreversible genes included xenobiotic metabolism signaling, bupropion degradation, and nicotine degradation. Conclusions: Analysis of repetitive sampling of the same individuals identified persistent smoking-induced dysregulation of the small airway epithelium transcriptome and the effect of smoking cessation. These results help identify targets for the development of therapies that can be applicable to smoking-related airway diseases.

Smoking during pregnancy is associated with the placental proteome.

Maternal smoking during pregnancy (MSDP) is a significant risk factor for the development of foetal, neonatal, and childhood morbidities. We hypothesized that infants exposed to MSDP have a distinct proteomic expression in their term placentas compared to infants without such an exposure. A total of 39 infants exposed (cord blood cotinine levels of >1 ng/mL) and 44 infants not exposed to MSDP were included in the study. Women with chronic disease, body mass index of > 30, or a history of uterine surgery were excluded. Total proteome abundance was analysed with quantitative mass spectrometry. For univariate analysis of differences in placental protein levels between groups, ANOVA with multiple testing corrections by the Benjamini-Hochberg method was used. For multivariate analysis, we used principal component analysis, partial least squares, lasso, random forest, and neural networks. The univariate analyses showed four differentially abundant proteins (PXDN, CYP1A1, GPR183, and KRT81) when heavy and moderate smoking groups were compared to non-smokers. With the help of machine learning, we found that an additional six proteins (SEPTIN3, CRAT, NAAA, CD248, CADM3, and ZNF648) were discriminants of MSDP. The placental abundance of these ten proteins together explained 74.1% of the variation in cord blood cotinine levels (p = 0.002). Infants exposed to MSDP showed differential abundance of proteins in term placentas. We report differential placental abundance of several proteins for the first time in the setting of MSDP. We believe that these findings supplement the current understanding of how MSDP affects the placental proteome.

Effects of medwakh smoking on salivary metabolomics and its association with altered oral redox homeostasis among youth.

The use of alternative tobacco products, particularly medwakh, has expanded among youth in the Middle East and around the world. The present study is conducted to investigate the biochemical and pathophysiological changes caused by medwakh smoking, and to examine the salivary metabolomics profile of medwakh smokers. Saliva samples were collected from 30 non-smokers and 30 medwakh smokers and subjected to metabolomic analysis by UHPLC-ESI-QTOF-MS. The CRP and Glutathione Peroxidase 1 activity levels in the study samples were quantified by ELISA and the total antioxidant capacity (TAC) by TAC assay kits. Statistical measurements and thorough validation of data obtained from untargeted metabolomics identified 37 uniquely and differentially abundant metabolites in saliva of medwakh smokers. The levels of phthalate, L-sorbose, cytosine, uridine, alpha-hydroxy hippurate, and L-nicotine were noticeably high in medwakh smokers. Likewise, 20 metabolic pathways were differentially altered in medwakh smokers. This study identified a distinctive saliva metabolomics profile in medwakh smokers associated with altered redox homeostasis, metabolic pathways, antioxidant system, and CRP levels. The impact of the altered metabolites in medwakh smokers and their diagnostic utility require further research in large cohorts.

Mechanisms Contributing to the Comorbidity of COPD and Lung Cancer.

Lung cancer and chronic obstructive pulmonary disease (COPD) often co-occur, and individuals with COPD are at a higher risk of developing lung cancer. While the underlying mechanism for this risk is not well understood, its major contributing factors have been proposed to include genomic, immune, and microenvironment dysregulation. Here, we review the evidence and significant studies that explore the mechanisms underlying the heightened lung cancer risk in people with COPD. Genetic and epigenetic changes, as well as the aberrant expression of non-coding RNAs, predispose the lung epithelium to carcinogenesis by altering the expression of cancer- and immune-related genes. Oxidative stress generated by tobacco smoking plays a role in reducing genomic integrity, promoting epithelial-mesenchymal-transition, and generating a chronic inflammatory environment. This leads to abnormal immune responses that promote cancer development, though not all smokers develop lung cancer. Sex differences in the metabolism of tobacco smoke predispose females to developing COPD and accumulating damage from oxidative stress that poses a risk for the development of lung cancer. Dysregulation of the lung microenvironment and microbiome contributes to chronic inflammation, which is observed in COPD and known to facilitate cancer initiation in various tumor types. Further, there is a need to better characterize and identify the proportion of individuals with COPD who are at a high risk for developing lung cancer. We evaluate possible novel and individualized screening strategies, including biomarkers identified in genetic studies and exhaled breath condensate analysis. We also discuss the use of corticosteroids and statins as chemopreventive agents to prevent lung cancer. It is crucial that we optimize the current methods for the early detection and management of lung cancer and COPD in order to improve the health outcomes for a large affected population.

Identification of 5-Hydroxycotinine in the Plasma of Nicotine-Treated Mice: Implications for Cotinine Metabolism and Disposition in Vivo.

Two oxidation products of cotinine, 5-hydroxycotinine (5-HC) and cotinine N-oxide (CNO), were identified for the first time in vivo in the plasma of C57BL/6 mice after injection of nicotine (1 mg/kg) or exposure to an e-cigarette (e-cig) containing 2.4% nicotine. Liquid chromatography-mass spectrometry was used to separate 3-hydroxycotinine (3-HC), 5-HC, and CNO and to quantify each by the sensitive direct detection of their parent ion with m/z of 193.097. In nicotine-injected mice, 5-HC was as abundant as 3-HC 15 minutes postinjection, and CNO was readily detectable. In e-cig-exposed mice with plasma nicotine levels resembling that of human smokers, plasma 5-HC and CNO, as well as 3-HC, were readily quantifiable at the end of the 4-hour exposure time. In nicotine-injected mice, the combined concentration of 3-HC plus 5-HC plus CNO, all formed from cotinine by CYP2A5, was higher (P < 0.01) in females than in males, although the male-female difference in cotinine plasma level did not reach statistical significance. The result highlights the importance of considering these three oxidation products of cotinine in examining cotinine metabolism and disposition. Coumarin 7-hydroxylase activity, a specific marker of CYP2A5, measured in the hepatic microsomes of untreated mice showed that females have higher activity (P < 0.001) than males (N = 8 per sex). The abundance of plasma 5-hydroxycotinine in nicotine-treated mice raises intriguing questions about the site of its origin (hepatic or possibly kidney CYP2A5) and the routes of its disposition because urinary excretion of 5-HC has not been detected by liquid chromatography with tandem mass spectrometry in mice and is controversial in human smokers. SIGNIFICANCE STATEMENT: Nicotine is the active ingredient of tobacco, but its elimination route through its biomarker cotinine is not fully understood. By liquid chromatography-mass spectrometry, this study has identified and quantified for the first time 5-hydroxycotinine and cotinine N-oxide, which are oxidation products of cotinine, in the plasma of mice treated with nicotine or exposed to e-cigarettes. The results raise intriguing questions about nicotine disposition in vivo in this well established preclinical model of human smokers.

Predicting nicotine metabolism across ancestries using genotypes.

BACKGROUND: There is a need to match characteristics of tobacco users with cessation treatments and risks of tobacco attributable diseases such as lung cancer. The rate in which the body metabolizes nicotine has proven an important predictor of these outcomes. Nicotine metabolism is primarily catalyzed by the enzyme cytochrone P450 (CYP2A6) and CYP2A6 activity can be measured as the ratio of two nicotine metabolites: trans-3'-hydroxycotinine to cotinine (NMR). Measurements of these metabolites are only possible in current tobacco users and vary by biofluid source, timing of collection, and protocols; unfortunately, this has limited their use in clinical practice. The NMR depends highly on genetic variation near CYP2A6 on chromosome 19 as well as ancestry, environmental, and other genetic factors. Thus, we aimed to develop prediction models of nicotine metabolism using genotypes and basic individual characteristics (age, gender, height, and weight). RESULTS: We identified four multiethnic studies with nicotine metabolites and DNA samples. We constructed a 263 marker panel from filtering genome-wide association scans of the NMR in each study. We then applied seven machine learning techniques to train models of nicotine metabolism on the largest and most ancestrally diverse dataset (N=2239). The models were then validated using the other three studies (total N=1415). Using cross-validation, we found the correlations between the observed and predicted NMR ranged from 0.69 to 0.97 depending on the model. When predictions were averaged in an ensemble model, the correlation was 0.81. The ensemble model generalizes well in the validation studies across ancestries, despite differences in the measurements of NMR between studies, with correlations of: 0.52 for African ancestry, 0.61 for Asian ancestry, and 0.46 for European ancestry. The most influential predictors of NMR identified in more than two models were rs56113850, rs11878604, and 21 other genetic variants near CYP2A6 as well as age and ancestry. CONCLUSIONS: We have developed an ensemble of seven models for predicting the NMR across ancestries from genotypes and age, gender and BMI. These models were validated using three datasets and associate with nicotine dosages. The knowledge of how an individual metabolizes nicotine could be used to help select the optimal path to reducing or quitting tobacco use, as well as, evaluating risks of tobacco use.

[Population rearrangement of B-lymphocytes expressing chemokine receptors in patients with chronic obstructive pulmonary disease]. / Populiatsionnaia perestroika B-limfotsitov, ékspressiruiushchikh khemokinovye retseptory, u patsientov s khronicheskoi obstruktivnoi bolezn'iu legkikh.

To date, there are no drugs that can prevent progressive destruction of lung tissue and small airway fibrosis in patients with chronic obstructive pulmonary disease (COPD). Therefore, molecular mechanisms of this disease are being studied. The aim of this study was to determine the chemokine receptor expression pattern of B-lymphocytes from peripheral blood and airways of patients with COPD. Peripheral blood was collected from 51 smokers with COPD, 21 healthy smokers, and 20 healthy non-smokers. Seven smokers with COPD and 7 healthy smokers were recruited to undergo bronchoscopy with bronchoalveolar lavage (BAL). The expression of chemokine receptors CCR5, CCR6, CCR7, CXCR3, CXCR4, and CXCR5 on the surface of blood and BAL B-lymphocytes was determined by flow cytometry. It was found that the percentage of blood B-lymphocytes expressing chemokine receptors CCR5 and CXCR3 was higher in smokers with COPD compared with healthy smokers and healthy non-smokers. The percentage of CD27⁺ B-cells expressing CCR5 and CXCR3 receptors exceeded the proportion of CD27⁻ B-lymphocytes expressing these receptors in peripheral blood of patients with COPD and healthy controls. In smoking patients with COPD, the percentage of BAL B-cells expressing receptors CCR5 and CXCR3 was also increased compared with healthy smokers. There were no differences in the percentage of B-lymphocytes expressing receptors CXCR4, CXCR5, CCR6, and CCR7 in both peripheral blood and BAL between smokers with COPD and healthy smokers. A greater percentage of CD27⁻ B-lymphocytes than CD27⁺ B-cells expressed receptors CXCR4, CXCR5, CCR6, and CCR7 in the peripheral blood of smokers with COPD and healthy controls. The results of this study indicate a modification in the chemokine receptor profile of B-lymphocytes in COPD.

The interaction between smoking and bladder cancer genetic variants on urothelial cancer risk by disease aggressiveness.

BACKGROUND: Smoking has shown interactions with bladder cancer (BC) genetic variants, especially N-acetyltransferase-2 (NAT2), a tobacco smoke metabolism gene, on BC risk. The interactions by disease aggressiveness are unknown. METHODS: We investigated the interaction between smoking and 18 single nucleotide polymorphisms (SNPs) for BC, individually and in a genetic risk score (GRS), on urothelial cancer (UC) risk including BC. We analysed data from 25,453 individuals with 520 incident UCs during follow-up, 339 non-aggressive (non-fatal, non-muscle invasive) and 163 aggressive (all other) UCs. Hazard ratios (HRs), absolute risks and additive and multiplicative interactions for two-by-two combinations of never/ever smoking with low/high genetic risk were calculated. RESULTS: Smoking and NAT2 rs1495741 interacted strongly, positively on aggressive UC on both the multiplicative (p = 0.004) and additive (p = 0.0002) scale, which was not observed for non-aggressive UC (pinteractions  ≥ 0.6). This manifested in a higher HR of aggressive UC by ever smoking for the slow acetylation NAT2 genotype (HR, 5.00 [95% confidence interval, 2.67-9.38]) than for intermediate/fast acetylation NAT2 (HR, 1.50 [0.83-2.71]), and in differences in absolute risks by smoking and NAT2 genotype. Smoking also interacted additively and positively with the GRS on any UC (p = 0.01) and non-aggressive UC (p = 0.02), but not on aggressive UC (p = 0.1). Gene-smoking interactions of lesser magnitude than for NAT2 were found for SNPs in APOBEC3A, SLC14A1 and MYNN. CONCLUSIONS: This study suggests that smoking increases UC risk more than expected when combined with certain genetic risks. Individuals with the slow acetylation NAT2 variant might particularly benefit from smoking intervention to prevent lethal UC; however, replication in larger studies is needed.

Effect of smoking cessation on cardiac troponin I concentrations.

Chronic elevation of cardiac troponin I (cTnI) is associated with heart failure and cardiovascular death. Paradoxically, observational studies have indicated that current smokers have lower cTnI concentrations than non-smokers. We examined determinants of cTnI in smokers and the effect of smoking cessation on cTnI. Overweight or obese smokers received motivational support and varenicline to aid cessation and dietary advice to limit weight gain. Quitters were defined according to the Russell standard (≤5 cigarettes after the quit date) and validated with expired breath CO <10 ppm. Of the total 122 participants, 108 completed assessments at 12 weeks and 78 were classified as quitters versus 30 who continued smoking. cTnI was measured with a high-sensitivity assay with a limit of detection of 1.2 ng/L (Abbott Diagnostics), and concentrations (log-transformed) were compared between quitters and continuing smokers. cTnI concentrations were significantly higher in men than women and correlated with age, but not with number of cigarettes/day. Quitters had median baseline and 12-week levels of 1.4 ng/L (interquartile range [IQR] 1.2-2.5) and 1.4 ng/L (IQR 1.2-2.4), respectively, while nonquitters had baseline and 12-week levels of 1.5 ng/L (IQR 1.2-2.9) and 1.8 ng/L (IQR 1.3-3.4), respectively. The change in cTnI concentrations from baseline to 12 weeks did not differ between quitters and continuous smokers (p = .7). The results suggest that smoking cessation does not affect levels of cTnI, a marker of chronic subclinical myocardial injury, in contrast to prior observational data suggesting that tobacco smoking is associated with lower cTn concentrations.

Renin-angiotensin system blockade on angiotensin-converting enzyme 2 and TMPRSS2 in human type II pneumocytes.

AIMS: Angiotensin-converting enzyme (ACE) 2 is the receptor for severe acute respiratory syndrome coronavirus 2 which causes coronavirus disease 2019 (COVID-19). Viral cellular entry requires ACE2 and transmembrane protease serine 2 (TMPRSS2). ACE inhibitors (ACEIs) or angiotensin (Ang) receptor blockers (ARBs) influence ACE2 in animals, though evidence in human lungs is lacking. We investigated ACE2 and TMPRSS2 in type II pneumocytes, the key cells that maintain lung homeostasis, in lung parenchymal of ACEI/ARB-treated subjects compared to untreated control subjects. MAIN METHODS: Ang II and Ang-(1-7) levels and ACE2 and TMPRSS2 protein expression were measured by radioimmunoassay and immunohistochemistry, respectively. KEY FINDINGS: We found that the ratio Ang-(1-7)/Ang II, a surrogate marker of ACE2 activity, as well as the amount of ACE2-expressing type II pneumocytes were not different between ACEI/ARB-treated and untreated subjects. ACE2 protein content correlated positively with smoking habit and age. The percentage of TMPRSS2-expressing type II pneumocytes was higher in males than females and in subjects under 60 years of age but it was not different between ACEI/ARB-treated and untreated subjects. However, there was a positive association of TMPRSS2 protein content with age and smoking in ACEI/ARB-treated subjects, with high TMPRSS2 protein levels most evident in ACEI/ARB-treated older adults and smokers. SIGNIFICANCE: ACEI/ARB treatment influences human lung TMPRSS2 but not ACE2 protein content and this effect is dependent on age and smoking habit. This finding may help explain the increased susceptibility to COVID-19 seen in smokers and older patients with treated cardiovascular-related pathologies.

Age influences on the molecular presentation of tumours.

Cancer is often called a disease of aging. There are numerous ways in which cancer epidemiology and behaviour change with the age of the patient. The molecular bases for these relationships remain largely underexplored. To characterise them, we analyse age-associations in the nuclear and mitochondrial somatic mutational landscape of 20,033 tumours across 35 tumour-types. Age influences both the number of mutations in a tumour (0.077 mutations per megabase per year) and their evolutionary timing. Specific mutational signatures are associated with age, reflecting differences in exogenous and endogenous oncogenic processes such as a greater influence of tobacco use in the tumours of younger patients, but higher activity of DNA damage repair signatures in those of older patients. We find that known cancer driver genes such as CDKN2A and CREBBP are mutated in age-associated frequencies, and these alter the transcriptome and predict for clinical outcomes. These effects are most striking in brain cancers where alterations like SUFU loss and ATRX mutation are age-dependent prognostic biomarkers. Using three cancer datasets, we show that age shapes the somatic mutational landscape of cancer, with clinical implications.

The unfavorable clinical outcome of COVID-19 in smokers is mediated by H3K4me3, H3K9me3 and H3K27me3 histone marks.

Smoking could predispose individuals to a more severe COVID-19 by upregulating a particular gene known as mdig, which is mediated through a number of well-known histone modifications. Smoking might regulate the transcription-activating H3K4me3 mark, along with the transcription-repressing H3K9me3 and H3K27me3 marks, in a way to favor SARS-CoV-2 entry by enhancing the expression of ACE2, NRP1 and NRP2, AT1R, CTSD and CTSL, PGE2 receptors 2-4, SLC6A20 and IL-6, all of which interact either directly or indirectly with important receptors, facilitating viral entry in COVID-19.

Lay abstract The role of smoking in development of several respiratory diseases has been clearly established. A significant proportion of these deleterious effects is mediated through epigenetic mechanisms, particularly histone modifications. Recent evidence indicates that smoking induces the expression of a mediator known as mdig, which in turn alters the transcription of several key proteins that have been implicated in development of COVID-19.