Role of Oxidative Stress in the Suppression of Immune Responses in Peripheral Blood Mononuclear Cells Exposed to Combustible Tobacco Product Preparation

A comprehensive review on immune checkpoint inhibitors induced cardiotoxicity characteristics and associated factors

Newly approved cancer drugs called ICIs have shown remarkable success in improving patient survival rates, but they also have the potential for inflammatory and immune-related side effects, including those affecting the cardiovascular system. Research has been conducted to understand the development of these toxicities and identify risk factors. This review focuses on the characteristics of ICI-induced cardiotoxicity and discusses the reported risk factors. It is important for cardio-oncologists to understand the basic concepts of these drugs to better understand how cardiotoxicities occur. It might be hard to find reports, where all patients treated with ICIs had developed cardiac toxicity, because there could be other existing and variable factors that influence the likelihood or risk of developing cardiotoxicity during treatment. Various clinical parameters have been explored as potential risk factors, and further investigation is needed through large-scale studies.

Tobacco Use and Response to Immune Checkpoint Inhibitor Therapy in Non-Small Cell Lung Cancer

Tobacco is a known risk factor for lung cancer, and continued tobacco use is associated with poorer outcomes across multiple lung cancer treatment modalities including surgery, chemotherapy and radiation therapy. Less is known about the association of tobacco use and outcomes with immune checkpoint inhibitors (ICIs), which are becoming an important part of the treatment landscape in lung cancer, both in metastatic and curative settings. We reviewed the literature on the association of tobacco and tumor biology as it relates to immunotherapy. We also reviewed the association of tobacco use on outcomes among phase III randomized clinical trials involving ICIs in non-small cell lung cancer (NSCLC). We identified that patients with a smoking history may have a greater benefit with ICI treatment compared to never smokers in both treatment-naïve (HR 0.82, 95% CI 0.69-0.97, vs. HR 1.06, 95% CI 0.81-1.38) and pre-treated (HR 0.79, 95% CI 0.70-0.90 vs. 1.03, 95% CI 0.74-1.43) settings. In trials where smoking status was further defined, ex-smokers appear to demonstrate greater benefit with ICI therapy compared to current smokers (HR 0.78, 95% CI 0.59-1.01 vs. 0.91, 95% CI 0.72-1.14). We conclude by offering our perspective on future directions in this area of research, including implementation of standardized collection and analysis of tobacco use in clinical trials involving ICI therapy in lung cancer and other disease sites, and also evaluating how tobacco may affect toxicities related to ICI therapy. Based on our review, we believe that a patient's history of tobacco smoking does have a role to play in guiding treatment decision making in patients with lung cancer.

Differential gene expression of 3D primary human airway cultures exposed to cigarette smoke and electronic nicotine delivery system (ENDS) preparations

BACKGROUND

Acute exposure to cigarette smoke alters gene expression in several biological pathways such as apoptosis, immune response, tumorigenesis and stress response, among others. However, the effects of electronic nicotine delivery systems (ENDS) on early changes in gene expression is relatively unknown. The objective of this study was to evaluate the early toxicogenomic changes using a fully-differentiated primary normal human bronchial epithelial (NHBE) culture model after an acute exposure to cigarette and ENDS preparations.

RESULTS

RNA sequencing and pathway enrichment analysis identified time and dose dependent changes in gene expression and several canonical pathways when exposed to cigarette preparations compared to vehicle control, including oxidative stress, xenobiotic metabolism, SPINK1 general cancer pathways and mucociliary clearance. No changes were observed with ENDS preparations containing up to 28 µg/mL nicotine. Full model hierarchical clustering revealed that ENDS preparations were similar to vehicle control.

CONCLUSION

This study revealed that while an acute exposure to cigarette preparations significantly and differentially regulated many genes and canonical pathways, ENDS preparations containing the same concentration of nicotine had very little effect on gene expression in fully-differentiated primary NHBE cultures.

Hydroquinone Exposure Worsens Rheumatoid Arthritis through the Activation of the Aryl Hydrocarbon Receptor and Interleukin-17 Pathways

Rheumatoid arthritis (RA) development is strongly associated with cigarette smoke exposure, which activates the aryl hydrocarbon receptor (AhR) as a trigger for Th17 inflammatory pathways. We previously demonstrated that the exposure to hydroquinone (HQ), one of the major compounds of cigarette tar, aggravates the arthritis symptomatology in rats. However, the mechanisms related to the HQ-related RA still remain elusive. Cell viability, cytokine secretion, and gene expression were measured in RA human fibroblast-like synoviocytes (RAHFLS) treated with HQ and stimulated or not with TNF-α. Antigen-induced arthritis (AIA) was also elicited in wild type (WT), AhR ^−/− or IL-17R ^−/− C57BL/6 mice upon daily exposure to nebulized HQ (25ppm) between days 15 to 21. At day 21, mice were challenged with mBSA and inflammatory parameters were assessed. The in vitro HQ treatment up-regulated TNFR1, TNFR2 expression, and increased ROS production. The co-treatment of HQ and TNF-α enhanced the IL-6 and IL-8 secretion. However, the pre-incubation of RAHFLS with an AhR antagonist inhibited the HQ-mediated cell proliferation and gene expression profile. About the in vivo approach, the HQ exposure worsened the AIA symptoms (edema, pain, cytokines secretion and NETs formation) in WT mice. These AIA effects were abolished in HQ-exposed AhR ^−/− and IL-17R ^−/− animals though. Our data demonstrated the harmful HQ influence over the onset of arthritis through the activation and proliferation of synoviocytes. The HQ-related RA severity was also associated with the activation of AhR and IL-17 pathways, highlighting how cigarette smoke compounds can contribute to the RA progression.

N-acetylcysteine alleviates ocular surface damage in STZ-induced diabetic mice by inhibiting the ROS/NLRP3/Caspase-1/IL-1β signaling pathway

Diabetes mellitus (DM) induces damage to the ocular surface, which leads to vision decline. In the current study, we investigated whether N-acetylcysteine (NAC) plays a protective role in diabetes-induced ocular surface damage. The diabetic mice model was treated with 0.3% NAC topically. Corneal epithelial integrity, tear volume and corneal sensitivity were examined by sodium fluorescein staining, phenol red cotton thread and esthesiometer respectively. The level of reactive oxygen species (ROS) was measured with 2',7-dichlorofluorescein diacetate. The expression of NLRP3, IL-1β and caspase-1 were evaluated by RT-PCR, western blot and immunostaining. The level of SOD1 was assessed by RT-PCR. We found that the expression of NLRP3, IL-1β and caspase-1 were elevated in diabetic cornea and conjunctiva. Treatment with NAC improved corneal epithelial integrity, increased tear production and corneal sensitivity in diabetic mice. Moreover, NAC markedly attenuated ROS accumulation and decreased NLRP3, IL-1β and caspase-1 levels in diabetic cornea and conjunctiva. These results suggest that NAC improves ocular surface damage in STZ-induced diabetic mice, which may be related to the inhibition of the ROS/NLRP3/Caspase-1/IL-1β signaling pathway.

Exposure to biomass smoke induces pulmonary Th17 cell differentiation by activating TLR2 on dendritic cells in a COPD rat model

Almost three billion people in developing countries are exposed to biomass smoke (BS), which predisposes them to developing chronic obstructive pulmonary disease (COPD). COPD is associated with abnormal innate and adaptive immune responses in the lungs and systemic circulation, but the mechanisms underlying BS-COPD development are uncertain. We investigated the role of dendritic cells (DCs) and interleukin (IL)-17A in BS-COPD. We investigated T helper cell responses in the BS-exposed COPD rat model by flow cytometry, quantitative PCR, and enzyme-linked immunosorbent assays. We conducted ex vivo experiments to determine which antigen-presenting cells induce Th17 cell responses. We evaluated the in vitro effects of BS-related particulate matter (BRPM) (2.5 μm) on the function of bone marrow-derived dendritic cells (BMDCs). We found that BS exposure enhanced Th17 responses in the lungs of the COPD-modelled rats, and the stimulated DCs (but not the macrophages) were sufficient to induce naïve CD4 + T cells to produce IL-17A in ex vivo experiments. BRPM significantly enhanced the maturation and activation of DCs through Toll-like receptor 2 (TLR2), but not TLR4, and induced Th17 responses. Therefore, BS activated lung DCs through TLR2, which led to Th17 responses and emphysema in the rats. This process is possibly therapeutically targetable.

Cigarette smoke preparations, not electronic nicotine delivery system preparations, induce features of lung disease in a 3D lung repeat-dose model

Cigarette smoking is a risk factor for several lung diseases, including chronic obstructive pulmonary disease, cardiovascular disease, and lung cancer. The potential health effects of chronic use of electronic nicotine delivery systems (ENDS) is unclear. This study utilized fully differentiated primary normal human bronchial epithelial (NHBE) cultures in a repeat-dose exposure to evaluate and compare the effect of combustible cigarette and ENDS preparations. We show that 1-h daily exposure of NHBE cultures over a 10-day period to combustible cigarette whole smoke-conditioned media (WS-CM) increased expression of oxidative stress markers, cell proliferation, airway remodeling, and cellular transformation markers and decreased mucociliary function including ion channel function and airway surface liquid. Conversely, aerosol conditioned media (ACM) from ENDS with similar nicotine concentration (equivalent-nicotine units) as WS-CM and nicotine alone had no effect on those parameters. In conclusion, primary NHBE cultures in a repeat-dose exposure system represent a good model to assess the features of lung disease. This study also reveals that cigarette and ENDS preparations differentially elicit several key endpoints, some of which are potential biomarkers for lung cancer or chronic obstructive pulmonary disease (COPD).

Differences in biomarkers of inflammation and immune responses in chronic smokers and moist snuff users

BACKGROUND

Cigarette smoking is a major risk factor for cancer and other diseases. While smoking induces chronic inflammation and aberrant immune responses, the effects of smokeless tobacco products (STPs) on immune responses is less clear. Here we evaluated markers related to immune regulation in smokers (SMK), moist snuff consumers (MSC) and non-tobacco consumers (NTC) to better understand the effects of chronic tobacco use.

MATERIALS AND METHODS

Several markers associated with immune regulation were measured in peripheral blood mononuclear cells (PBMCs) from SMK (n = 40), MSC (n = 40), and NTC (n = 40) by flow cytometry.

RESULTS

Relative to NTC, seven markers were significantly suppressed in SMK, whereas in MSC, only one marker was significantly suppressed. In a logistic regression model, markers including granzyme B⁺ lymphocytes, perforin⁺ lymphocytes, granzyme B⁺ CD8⁺T cells, and KLRB1⁺ CD8⁺ T cells remained as statistically significant predictors for classifying the three cohorts. Further, cell-surface receptor signaling pathways and cell-cell signaling processes were downregulated in SMK relative to MSC; chemotaxis and LPS-mediated signaling pathways, were upregulated in SMK compared to MSC. A network of the tested markers was constructed to visualize the immunosuppression in SMK relative to MSC.

CONCLUSION

Moist snuff consumption is associated with significantly fewer perturbations in inflammation and immune function biomarkers relative to smoking.

IMPACT

This work identifies several key immunological biomarkers that differentiate the effects of chronic smoking from the use of moist snuff. Additionally, a molecular basis for aberrant immune responses that could render smokers more susceptible for infections and cancer is provided.

Correlation between genetic variation in thymine DNA glycosylase and smoking behavior

Cigarette smoking is a major lifestyle factor leading to different human diseases. The DNA repair gene, thymine DNA glycosylase, is important to cell survival because it stops cells from becoming cancerous protecting/preventing DNA. Exposure to CS may induce genetic changes such as single nucleotide polymorphisms in DNA repair genes. Therefore, the purpose of this study was to investigate the genotype and allele distributions of four TDG SNPs with only smoking behavior in normal patients. Four TDG SNPs-rs4135066 (C/T), rs3751209 (A/G), rs1866074 (C/T), and rs1882018 (C/T) were analyzed by genotyping 235 and 239 blood samples collected from cigarette smokers and non-smokers, among the Saudi population. The results showed that TDG rs4135066 has a significant susceptibility effect observed in long-term smokers (>5 years; OR = 4.53; P = 0.0347) but not in short-term smokers (≤5 years) in contrast with non-smokers. Also, in smokers aged less than 29 years, the "CT," "TT," and "CT + TT" alleles of rs1882018 increased the risk of developing all diseases related to smoking by approximately 6, 4, and 5 times, respectively, in contrast with the ancestral "CC" homozygous allele. A comparison of the allele distributions of TDG SNPs in a Saudi population with those in other populations represented in the HapMap project showed that the genetic makeup of the Saudi Arabian population appears to differ from that of other ethnicities. Exceptions include the Yoruba people in Ibadan, Nigeria; those of Mexican ancestry in Los Angeles, California; the Luhya population in Webuye, Kenya; Gujarati Indians in Houston, Texas; and the Tuscan population in Italy, which showed similar allelic frequencies for rs3751209 compared to our Saudi population. In this ethnic, we have found a high variation in the distribution of the alleles and genotype frequencies on TDG gene. This variation on TDG SNP's with smoking could lead to increase the susceptibility to many diseases related to smoking habits in this population.

Tobacco extracts promote PD-L1 expression and enhance malignant biological differences via mTOR in gefitinib-resistant cell lines

BACKGROUND

The aim of this study was to investigate whether tobacco extracts could regulate PD-L1 expression and enhance malignant biological differences in gefitinib-resistant cell lines.

METHODS

We constructed gefitinib-resistant cells and observed the biological differences in gefitinib-resistant cells. The cells were stimulated with medium containing 5% volume of tobacco extract, and the change in PD-L1 expression and the mammalian target of rapamycin (mTOR) and p-mTOR expression in gefitinib-resistant cells treated with tobacco extracts was observed. We discussed the relationship between PD-L1 and mTOR.

RESULTS

Tobacco extracts could promote PD-L1 expression in the cell line. Western blot analysis showed that mTOR and p-mTOR were significantly enhanced in gefitinib-resistant cell lines cultured in the tobacco extracts. The mTOR signaling pathway was involved in PD-L1 expression and in regulating the expression of cytokines IL-6 and IL-23. In addition, the tobacco extracts could promote macrophage migration via mTOR/IL-6.

CONCLUSIONS

PD-L1 can transmit inhibitory signals and reduce the proliferation of CD8 + T cells in lymph nodes. Tobacco extracts upregulate PD-L1 expression via mTOR/IL-6. These results imply that lung cancer patients should not smoke and stay away from a smoke environment.

Combustible Cigarette and Smokeless Tobacco Product Preparations Differentially Regulate Intracellular Calcium Mobilization in HL60 Cells

Changes in the level of intracellular calcium ([Ca²⁺]_i) are central to leukocyte signaling and immune response. Although evidence suggests that cigarette smoking affects inflammatory response via an increase in intracellular calcium, it remains unclear if the use of smokeless tobacco (e.g., moist snuff) elicits a similar response. In this study, we evaluated the effects of tobacco product preparations (TPPs), including total particulate matter (TPM) from 3R4F reference cigarettes, smokeless tobacco extract (STE) from 2S3 reference moist snuff, and nicotine alone on Ca²⁺ mobilization in HL60 cells. Treatment with TPM, but not STE or nicotine alone, significantly increased [Ca²⁺]_i in a concentration-dependent manner in HL60 cells. Moreover, TPM-induced [Ca²⁺]_i increase was not related to extracellular Ca²⁺ and did not require the activation of the IP3 pathway nor involved the transient receptor potential (TRP) channels. Our findings indicate that, in cells having either intact or depleted endoplasmic reticulum (ER) Ca²⁺ stores, TPM-mediated [Ca²⁺]_i increase involves cytosolic Ca²⁺ pools other than thapsigargin-sensitive ER Ca²⁺ stores. These results, for the first time, demonstrate that TPM triggers [Ca²⁺]_i increases, while significantly higher nicotine equivalent doses of STE or nicotine alone, did not affect [Ca²⁺]_i under the experimental conditions. In summary, our study suggests that in contrast with STE or nicotine preparations, TPM activates Ca²⁺ signaling pathways in HL60 cells. The differential effect of combustible and non-combustible TPPs on Ca²⁺ mobilization could be a useful in vitro endpoint for tobacco product evaluation.

Cigarette smoke preparations, not moist snuff, impair expression of genes involved in immune signaling and cytolytic functions

Cigarette smoke-induced chronic inflammation is associated with compromised immune responses. To understand how tobacco products impact immune responses, we assessed transcriptomic profiles in peripheral blood mononuclear cells (PBMCs) pretreated with Whole Smoke-Conditioned Medium (WS-CM) or Smokeless Tobacco Extracts (STE), and stimulated with lipopolysaccharide, phorbol myristate and ionomycin (agonists). Gene expression profiles from PBMCs treated with low equi-nicotine units (0.3 μg/mL) of WS-CM and one high dose of STE (100 μg/mL) were similar to those from untreated controls. Cells treated with medium and high doses of WS-CM (1.0 and 3.0 μg/mL) exhibited significantly different gene expression profiles compared to the low WS-CM dose and STE. Pre-treatment with higher doses of WS-CM inhibited the expression of several pro-inflammatory genes (IFNγ, TNFα, and IL-2), while CSF1-R and IL17RA were upregulated. Pre-treatment with high doses of WS-CM abolished agonist-stimulated secretion of IFNγ, TNF and IL-2 proteins. Pathway analyses revealed that higher doses of WS-CM inhibited NF-ĸB signaling, immune cell differentiation and inflammatory responses, and increased apoptotic pathways. Our results show that pre-treatment of PBMCs with higher doses of WS-CM inhibits immune activation and effector cytokine expression and secretion, resulting in a reduced immune response, whereas STE exerted minimal effects.

Cigarette and ENDS preparations differentially regulate ion channels and mucociliary clearance in primary normal human bronchial 3D cultures

Cigarette smoking is known to disrupt the normal mucociliary function of the lungs, whereas the effect of electronic nicotine delivery systems (ENDS) is not completely understood. This study aimed to compare the effects of acute exposure of primary normal human bronchial epithelial (NHBE) 3D cultures at air-liquid interface to combustible cigarette and ENDS preparations on mucociliary function, including ion channel function, ciliary beat frequency (CBF), and airway surface liquid (ASL) height. Differentiated NHBE cultures were exposed to whole smoke-conditioned media (WS-CM) or total particulate matter (TPM) prepared from 3R4F reference cigarettes, whole aerosol-conditioned media (ACM) or e-TPM generated from a marketed ENDS product, or nicotine alone. We found that a dose of 7 μg/mL equi-nicotine units of cigarette TPM and WS-CM significantly decreased cystic fibrosis transmembrane conductance regulator (CFTR) and the epithelial sodium channel (ENaC) function, which regulates fluid homeostasis in the lung. Conversely, higher (56 µg/mL) equi-nicotine units of ENDS preparations or nicotine alone had no effect on CFTR and ENaC function. Despite a significant decrease in ion channel function, cigarette smoke preparations did not alter CBF and ASL. Similarly, ENDS preparations and nicotine alone had no effect on ASL and CBF. This study demonstrates that acute exposures of cigarette smoke preparations exert a notable inhibitory effect on CFTR and ENaC function compared with ENDS preparations. In summary, the functional assays described herein are potentially useful for tobacco product evaluations.

Association of modifiable risk factors and IL-6, CRP, and adiponectin: Findings from the 1993 Birth Cohort, Southern Brazil

Background

The literature on the relationship between lifestyle behaviors and inflammatory markers is scarce.

Methods

A birth cohort was followed since birth up to 22 years in Southern Brazil. Interleukin-6 (IL-6), C-reactive protein (CRP) and adiponectin were measured in nonfasting blood samples drawn at 18 and 22 years of age. Exposures including smoking, alcohol intake, physical inactivity and obesity, were collected at 15, 18 and 22 years. Cross sectional analyses were based on the number of follow-up visits with these exposures and the association with IL-6, CRP and adiponectin at 22 years old. We also carried out a longitudinal Generalized Least Squares (GLS) random-effects analysis with outcomes at 18 and at 22 years old. All analyses were adjusted for several covariates.

Results

The sample comprised 3,479 cohort members at 22 years. The presence of obesity at ≥ 2 follow-ups showed the highest mean values (SE) for IL-6 [2.45 (1.05)] and CRP [3.74 (1.11)] and the lowest mean value for adiponectin [8.60 (0.37)] (adjusted analyses, females) compared with other exposures; the highest mean of IL-6 [1.65 (1.05)] and CRP [1.78 (1.11)] and the lowest mean of adiponectin [9.98 (0.38)] were for the number of follow-ups with ≥2 exposures compared to those with no exposures at any follow-up (adjusted analyses, females). The longitudinal analysis showed an increase in obesity associated with IL-6 and CRP in both sexes and an inverse association with adiponectin in females; smoking (in males) was associated with IL-6 and CRP, harmful alcohol intake was associated with CRP in males, and increased in physical activity was inversely associated with CRP in men.

Conclusion

We concluded that obesity is the main exposure positively associated with IL-6 and CRP and inversely associated with adiponectin (mainly in females). Smoking is also associated with these markers in the longitudinal analysis (in males).

Conventional Western Treatment Associated With Chinese Herbal Medicine Ameliorates the Incidence of Head and Neck Cancer Among Patients With Esophageal Cancer

BACKGROUND

Because of advances in medical treatment, the survival of cancer patients is prolonged. In line with the prolonged survival time of cancer the incidence of second primary cancer has increased. There is currently no effective way to prevent the occurrence of secondary primary cancer (SPC).

OBJECTIVES

The aim of this study is to evaluate whether Chinese Herbal Medicine (CHM) is correlated with reduced occurrence of second primary cancer (SPC) of head and neck (H&N) in patients with esophageal cancer (EC).

METHOD

We identified 15,546 patients who were diagnosed with esophageal cancer between Jan 1, 2000, and Dec 31, 2010. The patients with H&N cancer before receiving CHM were excluded. After the selection and matching process, both CHM and non-CHM cohorts each contained 850 individuals. We compared the cumulative incidence of SPC of H&N with or without CHM treatment in patients with EC by the Kaplan-Meier method. NodeXL is used to run a network analysis of CHM to examine the association between herbs and formulas.

RESULTS

Compared with non-CHM users, CHM-users showed a reduced incidence rate of SPC of H&N among the patients with EC. Reduced cumulative incidence of SPC of H&N among patients with EC was noted in the CHM cohort compared to the non-CHM cohort. The most commonly used single herbs and formulas were associated with reducing SPC occurrence.

CONCLUSION

We propose that CHM as an adjuvant therapy may prevent the occurrence of SPC of H&N in patients with EC.

Effect of the thymine-DNA glycosylase rs4135050 variant on Saudi smoker population

Background

Thymine‐DNA glycosylase (TDG) is an essential DNA‐repair enzyme which works in both epigenetic regulation and genome maintenance. It is also responsible for efficient correction of multiple endogenous DNA lesions which occur commonly in mammalian genomes. Research of genetic variants such as SNPs, resulting in disease, is predicted to yield clinical advancements through the identification of sensitive genetic markers and the development of disease prevention and therapy. To that end, the main objective of the present study is to identify the possible interactions between cigarette smoking and the rs4135050 variant of the TDG gene, situated in the intron position, among Saudi individuals.

Methods

TDG rs4135050 (A/T) was investigated by genotyping 239, and 235 blood specimens were obtained from nonsmokers and smokers of cigarette respectively.

Results

T allele frequency was found which showed a significant protective effect on Saudi male smokers (OR = 0.64, p = 0.0187) compared to nonsmoking subjects, but not in female smokers. Furthermore, smokers aged less than 29 years, the AT and AT+TT genotypes decreased more than four times the risk of initiation of smoking related‐diseases compare to the ancestral AA homozygous genotype. Paradoxically, the AT (OR = 3.88, p = 0.0169) and AT+TT (OR = 2.86, p = 0.0420) genotypes were present at a higher frequency in smoking patients aged more than 29 years as compared to nonsmokers at the same ages.

Conclusion

Depending on the gender and age of patients, TDG rs4135050 may provide a novel biomarker for the early diagnosis and prevention of several diseases caused by cigarette smoking.

Distinct gene expression changes in human peripheral blood mononuclear cells treated with different tobacco product preparations

Cigarette smoking exerts diverse physiological effects including immune suppression. To better characterize the biological effects of different categories of tobacco products, a genome-wide gene expression study was performed. Transcriptomic profiling was performed in PBMCs treated with different equi-nicotine units of aqueous extracts of cigarette smoke (termed Whole Smoke-Conditioned Medium, or WS-CM), or a single dose smokeless tobacco extract (STE) prepared from reference tobacco products. WS-CM induced dose-dependent changes in the expression of several genes. No significant expression differences between low WS-CM and media control were detected. However, transcripts were significantly affected by medium WS-CM (479), high WS-CM (2, 703), and STE (2, 156). The overlap between medium WS-CM and STE, and high WS-CM and STE, was minimal (34 and 65 transcripts, respectively). Hierarchical clustering revealed that gene expression profiles for STE and medium WS-CM co-clustered, while those affected by the high dose of WS-CM clustered distinctly. Functional analysis revealed that WS-CM, but not STE, uniquely affected genes involved in immune cell development and inflammatory response. Cascades of upstream regulators (e.g., TNF, IL1β, NFƙB) were identified for the observed gene expression changes and generally suppressed by WS-CM, but not by STE. Collectively, these findings demonstrate that combustible and non-combustible tobacco products elicit distinct biological effects, which could explain the observed chronic immune suppression in smokers.

The role of E3 ubiquitin ligase seven in absentia homolog in the innate immune system: An overview

The innate immune system has been considered as an ancient system and less important than the adaptive immune system. However, the interest in innate immunity has grown significantly in the past few years marked by the identification of Toll-like receptors, a member of pattern recognition receptors (PRRs). The PRRs are crucial for the identification of self- and non-self-antigen and play a role in the initiation of signaling events that activate the effective immune response. These sensor signals through interweaving signaling cascades which result in the production of interferons and cytokines as the effector of immune system. Ubiquitin and ubiquitin-like modifiers (UBLs) actively mediate the rapid and versatile regulatory processes that initiate the activation of the innate immune system cascade. The seven in absentia homolog (SIAH) is a potent RING finger E3 ubiquitin ligase that is known to involve in several stress responses, including hypoxia, oxidative stress, DNA damage stress, and inflammation. In this review, the role of SIAH will be discussed as an E3 ubiquitin ligase on the regulation of innate immune.

Cytokine profiling of exosomes derived from the plasma of HIV-infected alcohol drinkers and cigarette smokers

Cytokines and chemokines circulate in plasma and may be transferred to distant sites, via exosomes. HIV infection is associated with dysregulation of cytokines and chemokines, which subsequently contribute to the pathogenesis of HIV. Alcohol and tobacco exposure, which are prevalent in HIV-infected individuals, may induce changes in the expression of cytokines and chemokines. Therefore, our aim in this study was to quantify plasma exosomal cytokines and chemokines that we expect to exacerbate toxicity or disease progression in HIV-positive drug abusers. We measured the levels of cytokines and chemokines in the plasma and plasma exosomes of 39 patients comprising six groups: HIV-negative and HIV-positive non drug abusers, HIV-negative and HIV-positive alcohol users, and HIV-negative and HIV positive tobacco smokers. We measured six cytokines (TNF-α, IL-1β, IL-8, IL-6, IL-1ra, IL-10) and two chemokines (MCP-1 and RANTES). All were present in exosomes of healthy subjects, but their levels varied between different study groups. HIV-positive alcohol drinkers had higher levels of plasma IL-8 compared to those of HIV-positive non-drinkers. The IL-1ra level was significantly higher in exosomes of non-HIV-infected alcohol drinkers compared to those of HIV-positive alcohol drinkers. Interestingly, the IL-10 level was higher in exosomes compared with their respective plasma levels in all study groups except HIV-positive non-alcohol drinkers. IL-10 was completely packaged in exosomes of HIV-positive smokers. HIV-positive smokers had significantly higher levels of plasma IL-8 compared with HIV-positive non-smokers and significantly higher exosomal IL-6 levels compared with HIV-negative subjects. HIV-positive smokers had significantly increased plasma levels of IL-1ra compared to HIV-positive non-smokers. The MCP-1 levels in the plasma of HIV-positive smokers was significantly higher than in either HIV-positive non-drug abusers or HIV-negative smokers. Overall, the findings suggest that plasma cytokines and chemokines are packaged in exosomes at varying degrees in different study groups. Exosomal cytokines and chemokines are likely to have a significant biological role at distant sites including cells in the brain.

Tobacco Smoke Induces and Alters Immune Responses in the Lung Triggering Inflammation, Allergy, Asthma and Other Lung Diseases: A Mechanistic Review

Many studies have been undertaken to reveal how tobacco smoke skews immune responses contributing to the development of chronic obstructive pulmonary disease (COPD) and other lung diseases. Recently, environmental tobacco smoke (ETS) has been linked with asthma and allergic diseases in children. This review presents the most actual knowledge on exact molecular mechanisms responsible for the skewed inflammatory profile that aggravates inflammation, promotes infections, induces tissue damage, and may promote the development of allergy in individuals exposed to ETS. We demonstrate how the imbalance between oxidants and antioxidants resulting from exposure to tobacco smoke leads to oxidative stress, increased mucosal inflammation, and increased expression of inflammatory cytokines (such as interleukin (IL)-8, IL-6 and tumor necrosis factor α ([TNF]-α). Direct cellular effects of ETS on epithelial cells results in increased permeability, mucus overproduction, impaired mucociliary clearance, increased release of proinflammatory cytokines and chemokines, enhanced recruitment of macrophages and neutrophils and disturbed lymphocyte balance towards Th2. The plethora of presented phenomena fully justifies a restrictive policy aiming at limiting the domestic and public exposure to ETS.

Transcriptional differences between smokers and non-smokers and variance by obesity as a risk factor for human sensitivity to environmental exposures

BACKGROUND

Obesity has been shown to alter response to air pollution and smoking but underlying biological mechanisms are largely unknown and few studies have explored mechanisms by which obesity increases human sensitivity to environmental exposures.

OBJECTIVE

Overall study goals were to investigate whole blood gene expression in smokers and non-smokers to examine associations between cigarette smoke and changes in gene expression by obesity status and test for effect modification.

METHODS

Relative fold-change in mRNA expression levels of 84 genes were analyzed using a Toxicity and Stress PCR array among 50 21-54 year old adults. Data on smoking status was confirmed using urinary cotinine levels. Adjusted models included age, gender, white blood cell count and body-mass index.

RESULTS

Models comparing gene expression of smokers vs. non-smokers identified six differentially expressed genes associated with smoking after adjustments for covariates. Obesity was associated with 29 genes differentially expressed compared to non-obese. We also identified 9 genes with significant smoking/obesity interactions influencing mRNA levels in adjusted models comparing expression between smokers vs non-smokers for four DNA damage related genes (GADD45A, DDB2, RAD51 and P53), two oxidative stress genes (FTH1, TXN), two hypoxia response genes (BN1P3lL, ARNT), and one gene associated with unfolded protein response (ATF6B).

CONCLUSIONS

Findings suggest that obesity alters human sensitivity to smoke exposures through several biological pathways by modifying gene expression. Additional studies are needed to fully understand the clinical impact of these effects, but risk assessments should consider underlying phenotypes, such as obesity, that may modulate sensitivity of vulnerable populations to environmental exposures.