1
|
Easwaran M, Maria CS, Martinez JD, Hung B, Yu X, Soo J, Kimura A, Gross ER, Erickson-DiRenzo E. Effects of Short-term Electronic(e)-Cigarette Aerosol Exposure in the Mouse Larynx. Laryngoscope 2024; 134:1316-1326. [PMID: 37698394 PMCID: PMC10922082 DOI: 10.1002/lary.31043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 08/17/2023] [Accepted: 08/29/2023] [Indexed: 09/13/2023]
Abstract
OBJECTIVES The effects of electronic cigarettes (e-cigarettes) on the larynx are relatively unknown. This study examined the short-term effects of e-cigarette inhalation on cellular and inflammatory responses within the mouse laryngeal glottic and subglottic regions after exposure to pod-based devices (JUUL). METHODS Male C57BL6/J mice (8-9 weeks) were assigned to control (n = 9), JUUL flavors Mint (JMi; n = 10) or Mango (JMa; n = 10). JUUL mice were exposed to 2 h/day for 1, 5, and 10 days using the inExpose inhalation system. Control mice were in room air. Vocal fold (VF) epithelial thickness, cell proliferation, subglandular area and composition, inflammatory cell infiltration, and surface topography were evaluated in the harvested larynges. Mouse body weight and urinary nicotine biomarkers were also measured. Chemical analysis of JUUL aerosols was conducted using selective ion flow tube mass spectrometry. RESULTS JUUL-exposed mice had reduced body weight after day 5. Urinary nicotine biomarker levels indicated successful JUUL exposure and metabolism. Quantitative analysis of JUUL aerosol indicated that chemical constituents differ between JMi and JMa flavors. VF epithelial thickness, cellular proliferation, glandular area, and surface topography remained unchanged after JUUL exposures. Acidic mucus content increased after 1 day of JMi exposure. VF macrophage and T-cell levels slightly increased after 10 days of JMi exposures. CONCLUSIONS Short-term e-cigarette exposures cause minimal flavor- and region-specific cellular and inflammatory changes in the mouse larynx. This work provides a foundation for long-term studies to determine if these responses are altered with multiple e-cigarette components and concentrations. LEVEL OF EVIDENCE N/A Laryngoscope, 134:1316-1326, 2024.
Collapse
Affiliation(s)
- Meena Easwaran
- Department of Otolaryngology - Head & Neck Surgery, School of Medicine, Stanford University, Stanford, CA
| | - Chloe Santa Maria
- Department of Otolaryngology - Head & Neck Surgery, School of Medicine, Stanford University, Stanford, CA
| | - Joshua D. Martinez
- Department of Otolaryngology - Head & Neck Surgery, School of Medicine, Stanford University, Stanford, CA
| | - Barbara Hung
- Department of Anesthesiology, Perioperative and Pain Medicine, School of Medicine, Stanford University, Stanford, CA
| | - Xuan Yu
- Department of Anesthesiology, Perioperative and Pain Medicine, School of Medicine, Stanford University, Stanford, CA
| | - Joanne Soo
- Department of Otolaryngology - Head & Neck Surgery, School of Medicine, Stanford University, Stanford, CA
| | - Akari Kimura
- Department of Otolaryngology - Head & Neck Surgery, School of Medicine, Stanford University, Stanford, CA
| | - Eric R. Gross
- Department of Anesthesiology, Perioperative and Pain Medicine, School of Medicine, Stanford University, Stanford, CA
| | - Elizabeth Erickson-DiRenzo
- Department of Otolaryngology - Head & Neck Surgery, School of Medicine, Stanford University, Stanford, CA
| |
Collapse
|
2
|
Lamb T, Kaur G, Rahman I. Tobacco-derived and tobacco-free nicotine cause differential inflammatory cell influx and MMP-9 in mouse lung. Respir Res 2024; 25:51. [PMID: 38254111 PMCID: PMC10804532 DOI: 10.1186/s12931-023-02662-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 12/29/2023] [Indexed: 01/24/2024] Open
Abstract
BACKGROUND Electronic nicotine delivery systems (ENDS) or electronic cigarettes (e-cigarettes) aerosolize an e-liquid composed of propylene glycol (PG) and vegetable glycerin (VG) as humectants, flavoring chemicals, and nicotine. Nicotine naturally occurs in two isomers R- and S-nicotine, with tobacco-derived nicotine (TDN) composed of S-nicotine, and tobacco-free/synthetic nicotine (TFN) composed of a racemic mixture of R- and S-nicotine. Currently, there is limited knowledge of the potential differences in the toxicity of TFN versus TDN. We hypothesized that exposure of TFN and TDN salts to C57BL/6J mice would result in a differential response in lung inflammation and protease/ antiprotease imbalance. METHODS Five-week-old male and female C57BL/6J mice were exposed to air, PG/VG, PG/VG with TFN salts (TFN), or PG/VG with TDN salts (TDN) by nose-only exposure. Lung inflammatory cell counts, cytokine/chemokine levels, and matrix metalloproteinase (MMP) protein abundance and activity levels were determined by flow cytometry, ELISA, immunoblotting, and gel zymography, respectively. RESULTS Exposure to the humectants (PG/VG) alone increased cytokine levels- IL-6, KC, and MCP-1 in the BALF and KC levels in lung homogenate of exposed mice. While no change was observed in the cytokine levels in lung homogenate of TDN aerosol exposed mice, exposure to TFN aerosols resulted in an increase in KC levels in the lungs of these mice compared to air controls. Interestingly, exposure to TDN aerosols increased MMP-9 protein abundance in the lungs of female mice, while exposure to TFN aerosol showed no change. The metabolism of nicotine or the clearance of cotinine for TFN exposure may differ from that for TDN. CONCLUSION Exposure to humectants, PG/VG alone, induces an inflammatory response in C57BL/6J mice. TFN and TDN salts show distinct changes in inflammatory responses and lung proteases on acute exposures. These data suggest variable toxicological profiles of the two forms of nicotine in vivo. Future work is thus warranted to delineate the harmful effects of synthetic/natural nicotine with humectants to determine the potential toxicological risks for users.
Collapse
Affiliation(s)
- Thomas Lamb
- Department of Environmental Medicine, University of Rochester Medical Center, 601 Elmwood Avenue, Box 850, Rochester, NY, 14642, USA
| | - Gagandeep Kaur
- Department of Environmental Medicine, University of Rochester Medical Center, 601 Elmwood Avenue, Box 850, Rochester, NY, 14642, USA
| | - Irfan Rahman
- Department of Environmental Medicine, University of Rochester Medical Center, 601 Elmwood Avenue, Box 850, Rochester, NY, 14642, USA.
| |
Collapse
|
3
|
Lamb T, Kaur G, Rahman I. Tobacco-Derived and Tobacco-Free Nicotine cause differential inflammatory cell influx and MMP9 in mouse lung. Res Sq 2023:rs.3.rs-3650978. [PMID: 38077054 PMCID: PMC10705704 DOI: 10.21203/rs.3.rs-3650978/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
Electronic nicotine delivery systems (ENDS) or electronic cigarettes (e-cigarettes) have propylene glycol (PG) and vegetable glycerin (VG) as humectants, flavoring chemicals, and nicotine. Nicotine naturally occurs in two isomers R- and S-nicotine, with both tobacco-derived nicotine (TDN) composed of S-nicotine and synthetic nicotine (TFN) composed of a racemic mixture of R- and S-nicotine. Currently there is limited knowledge of the potential differences in the toxicity of TFN vs TDN. We hypothesized that exposure of TFN salts to C57BL/6J mice will result in a differential response in inflammation and lung protease and antiprotease imbalance compared to TDN salts exposed mice. We studied the toxicological impact of these isomers by exposing mice to air, PG/VG, PG/VG with TFN salts, or PG/VG with TDN salts by nose-only exposure and measured the cytokine levels in BALF and lung homogenate along with MMP protein abundance in the lungs of exposed mice. Exposure to the humectants, PG/VG, used in e-cigarettes alone was able to increase cytokine levels-IL-6, KC, and MCP-1 in BALF and KC levels in lung homogenate. Further, it showed differential responses on exposure to PG/VG with TDN salts and PG/VG with TFN salts since PG/VG with TDN salts did not alter the cytokine levels in lung homogenate while PG/VG with TFN salts resulted in an increase in KC levels. PG/VG with TDN salts increased the levels of MMP9 protein abundance in female exposed mice, while PG/VG with TFN salts did not alter MMP9 levels in female mice. The metabolism of nicotine or the clearance of cotinine from TFN may differ from the metabolism of nicotine or the clearance of cotinine from TDN. Thus exposure of humectants alone to induce an inflammatory response while PG/VG with TFN salts and PG/VG with TDN salts may differentially alter inflammatory responses and lung proteases in acute exposures. These data suggest the harmful effects of synthetic/natural nicotine and PG/VG and potential toxicological risk for users.
Collapse
|
4
|
Muthumalage T, Rahman I. Pulmonary immune response regulation, genotoxicity, and metabolic reprogramming by menthol- and tobacco-flavored e-cigarette exposures in mice. Toxicol Sci 2023; 193:146-165. [PMID: 37052522 PMCID: PMC10230290 DOI: 10.1093/toxsci/kfad033] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2023] Open
Abstract
Menthol and tobacco flavors are available for almost all tobacco products, including electronic cigarettes (e-cigs). These flavors are a mixture of chemicals with overlapping constituents. There are no comparative toxicity studies of these flavors produced by different manufacturers. We hypothesized that acute exposure to menthol and tobacco-flavored e-cig aerosols induces inflammatory, genotoxicity, and metabolic responses in mouse lungs. We compared two brands, A and B, of e-cig flavors (PG/VG, menthol, and tobacco) with and without nicotine for their inflammatory response, genotoxic markers, and altered genes and proteins in the context of metabolism by exposing mouse strains, C57BL/6J (Th1-mediated) and BALB/cJ (Th2-mediated). Brand A nicotine-free menthol exposure caused increased neutrophils and differential T-lymphocyte influx in bronchoalveolar lavage fluid and induced significant immunosuppression, while brand A tobacco with nicotine elicited an allergic inflammatory response with increased Eotaxin, IL-6, and RANTES levels. Brand B elicited a similar inflammatory response in menthol flavor exposure. Upon e-cig exposure, genotoxicity markers significantly increased in lung tissue. These inflammatory and genotoxicity responses were associated with altered NLRP3 inflammasome and TRPA1 induction by menthol flavor. Nicotine decreased surfactant protein D and increased PAI-1 by menthol and tobacco flavors, respectively. Integration of inflammatory and metabolic pathway gene expression analysis showed immunometabolic regulation in T cells via PI3K/Akt/p70S6k-mTOR axis associated with suppressed immunity/allergic immune response. Overall, this study showed the comparative toxicity of flavored e-cig aerosols, unraveling potential signaling pathways of nicotine and flavor-mediated pulmonary toxicological responses, and emphasized the need for standardized toxicity testing for appropriate premarket authorization of e-cigarette products.
Collapse
Affiliation(s)
- Thivanka Muthumalage
- Department of Environmental Medicine, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, New York 14642, USA
| | - Irfan Rahman
- Department of Environmental Medicine, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, New York 14642, USA
| |
Collapse
|
5
|
Rodriguez-Herrera AJ, de Souza ABF, Castro TDF, Machado-Junior PA, Gomez ECM, Menezes TP, da Cruz Castro ML, Talvani A, Costa DC, Cangussú SD, Bezerra FS. Long-term e-cigarette aerosol exposure causes pulmonary emphysema in adult female and male mice. Regul Toxicol Pharmacol 2023:105412. [PMID: 37247649 DOI: 10.1016/j.yrtph.2023.105412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 05/14/2023] [Accepted: 05/21/2023] [Indexed: 05/31/2023]
Abstract
This study aimed to evaluate long-term exposure to conventional cigarette smoke (CC) and electronic cigarette (EC) aerosol in adult male and female C57BL/6 mice. Forty-eight C57BL/6 mice were used, male (n = 24) and female (n = 24), both were divided into three groups: control, CC and EC. The CC and EC groups were exposed to cigarette smoke or electronic cigarette aerosol, respectively, 3 times a day for 60 consecutive days. Afterwards, they were maintained for 60 days without exposure to cigarettes or electronic cigarette aerosol. Both cigarettes promoted an influx of inflammatory cells to the lung in males and females. All animals exposed to CC and EC showed an increase in lipid peroxidation and protein oxidation. There was an increase of IL-6 in males and females exposed to EC. The IL-13 levels were higher in the females exposed to EC and CC. Both sexes exposed to EC and CC presented tissue damage characterized by septal destruction and increased alveolar spaces compared to control. Our results demonstrated that exposure to CC and EC induced pulmonary emphysema in both sexes, and females seem to be more susceptible to EC.
Collapse
Affiliation(s)
- Andrea Jazel Rodriguez-Herrera
- Laboratory of Experimental Pathophysiology, Department of Biological Sciences and Center of Research in Biological Sciences, Federal University of Ouro Preto (UFOP), 35400-000, Ouro Preto, MG, Brazil
| | - Ana Beatriz Farias de Souza
- Laboratory of Experimental Pathophysiology, Department of Biological Sciences and Center of Research in Biological Sciences, Federal University of Ouro Preto (UFOP), 35400-000, Ouro Preto, MG, Brazil
| | - Thalles de Freitas Castro
- Laboratory of Experimental Pathophysiology, Department of Biological Sciences and Center of Research in Biological Sciences, Federal University of Ouro Preto (UFOP), 35400-000, Ouro Preto, MG, Brazil
| | - Pedro Alves Machado-Junior
- Laboratory of Experimental Pathophysiology, Department of Biological Sciences and Center of Research in Biological Sciences, Federal University of Ouro Preto (UFOP), 35400-000, Ouro Preto, MG, Brazil
| | - Elena Cecilia Marcano Gomez
- Laboratory of Experimental Pathophysiology, Department of Biological Sciences and Center of Research in Biological Sciences, Federal University of Ouro Preto (UFOP), 35400-000, Ouro Preto, MG, Brazil
| | - Tatiana Prata Menezes
- Laboratory of Immunobiology of Inflammation, Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto (UFOP), 35400-000, Ouro Preto, MG, Brazil
| | - Maria Laura da Cruz Castro
- Laboratory of Metabolic Biochemistry, Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto (UFOP), 35400-000, Ouro Preto, MG, Brazil
| | - André Talvani
- Laboratory of Immunobiology of Inflammation, Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto (UFOP), 35400-000, Ouro Preto, MG, Brazil
| | - Daniela Caldeira Costa
- Laboratory of Metabolic Biochemistry, Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto (UFOP), 35400-000, Ouro Preto, MG, Brazil
| | - Sílvia Dantas Cangussú
- Laboratory of Experimental Pathophysiology, Department of Biological Sciences and Center of Research in Biological Sciences, Federal University of Ouro Preto (UFOP), 35400-000, Ouro Preto, MG, Brazil
| | - Frank Silva Bezerra
- Laboratory of Experimental Pathophysiology, Department of Biological Sciences and Center of Research in Biological Sciences, Federal University of Ouro Preto (UFOP), 35400-000, Ouro Preto, MG, Brazil.
| |
Collapse
|
6
|
Lamb T, Rahman I. Pro-inflammatory effects of aerosols from e-cigarette-derived flavoring chemicals on murine macrophages. Toxicol Rep 2023; 10:431-435. [PMID: 37090225 PMCID: PMC10119680 DOI: 10.1016/j.toxrep.2023.04.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/24/2023] [Accepted: 04/05/2023] [Indexed: 04/08/2023] Open
Abstract
Macrophages treated with the flavoring chemicals found in flavored electronic cigarettes have been shown to induce an inflammatory response, however, limited data are available on the effect of aerosol exposure to these chemicals. We hypothesized that aerosol exposure to flavoring chemicals found in commercially available flavored e-liquids would result in an increase in pro-inflammatory cytokines in macrophages. Raw264.7 macrophage cell lines were exposed to a low and high dose of propylene glycol/vegetable glycerin (PG/VG) with almond flavoring benzaldehyde (280 μg/ml and 2.1 mg/ml), PG/VG with spicy/clove flavoring eugenol (3.5 mg/ml and 12 mg/ml), or PG/VG with apple flavoring hexyl acetate (500 μg/ml and 2.5 mg/ml). Exposure to PG/VG with 2.1 mg/ml benzaldehyde resulted in a significant increase in KC levels compared to air and PG/VG exposed cells. Exposure to PG/VG with both doses of hexyl acetate resulted in a significant increase in KC and IL-6 levels compared to air exposed cells. Exposure to PG/VG with both doses of eugenol resulted in a significant increase in KC and IL-6 levels compared to air and PG/VG exposed cells. These data indicate the ability of aerosol exposure to e-cigarette flavoring chemicals to significantly increase pro-inflammatory cytokine release in macrophages.
Collapse
Affiliation(s)
| | - Irfan Rahman
- Correspondence to: Department of Environmental Medicine, University of Rochester Medical Center, Box 850, 601 Elmwood Avenue, Rochester 14642, NY, USA.
| |
Collapse
|
7
|
Been T, Alakhtar B, Traboulsi H, Tsering T, Bartolomucci A, Heimbach N, Paoli S, Burnier J, Mann KK, Eidelman DH, Baglole CJ. Chronic low-level JUUL aerosol exposure causes pulmonary immunologic, transcriptomic, and proteomic changes. FASEB J 2023; 37:e22732. [PMID: 36694994 DOI: 10.1096/fj.202201392r] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 11/18/2022] [Accepted: 12/14/2022] [Indexed: 01/26/2023]
Abstract
E-cigarettes currently divide public opinion, with some considering them a useful tool for smoking cessation and while others are concerned with potentially adverse health consequences. However, it may take decades to fully understand the effects of e-cigarette use in humans given their relative newness on the market. This highlights the need for comprehensive preclinical studies investigating the effects of e-cigarette exposure on health outcomes. Here, we investigated the impact of chronic, low-level JUUL aerosol exposure on multiple lung outcomes. JUUL is a brand of e-cigarettes popular with youth and young adults. To replicate human exposures, 8- to 12-week-old male and female C57BL/6J mice were exposed to commercially available JUUL products (containing 59 mg/ml nicotine). Mice were exposed to room air, PG/VG, or JUUL daily for 4 weeks. After the exposure period, inflammatory markers were assessed via qRT-PCR, multiplex cytokine assays, and differential cell count. Proteomic and transcriptomic analyses were also performed on samples isolated from the lavage of the lungs; this included unbiased analysis of proteins contained within extracellular vesicles (EVs). Mice exposed to JUUL aerosols for 4 weeks had significantly increased neutrophil and lymphocyte populations in the BAL and some changes in cytokine mRNA expression. However, BAL cytokines did not change. Proteomic and transcriptomic analysis revealed significant changes in numerous biological pathways including neutrophil degranulation, PPAR signaling, and xenobiotic metabolism. Thus, e-cigarettes are not inert and can cause significant cellular and molecular changes in the lungs.
Collapse
Affiliation(s)
- Terek Been
- Department of Pharmacology & Therapeutics, McGill University, Montreal, Quebec, Canada.,Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - Bayan Alakhtar
- Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada
| | - Hussein Traboulsi
- Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - Thupten Tsering
- Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada.,Department of Pathology, McGill University, Montreal, Quebec, Canada
| | - Alexandra Bartolomucci
- Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada.,Department of Pathology, McGill University, Montreal, Quebec, Canada
| | - Nicole Heimbach
- Department of Pharmacology & Therapeutics, McGill University, Montreal, Quebec, Canada.,Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - Sofia Paoli
- Department of Pharmacology & Therapeutics, McGill University, Montreal, Quebec, Canada.,Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - Julia Burnier
- Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada.,Department of Pathology, McGill University, Montreal, Quebec, Canada
| | - Koren K Mann
- Department of Pharmacology & Therapeutics, McGill University, Montreal, Quebec, Canada.,Department of Oncology, Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada
| | - David H Eidelman
- Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada.,Department of Medicine, McGill University, Montreal, Quebec, Canada
| | - Carolyn J Baglole
- Department of Pharmacology & Therapeutics, McGill University, Montreal, Quebec, Canada.,Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada.,Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada.,Department of Pathology, McGill University, Montreal, Quebec, Canada.,Department of Medicine, McGill University, Montreal, Quebec, Canada
| |
Collapse
|
8
|
Sobczak A, Kośmider L. Advantages and Disadvantages of Electronic Cigarettes. Toxics 2023; 11:66. [PMID: 36668791 PMCID: PMC9861996 DOI: 10.3390/toxics11010066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 01/05/2023] [Indexed: 06/17/2023]
Abstract
Despite nearly nine thousand publications on e-cigarettes (EC) in the PubMed database, there is still no consensus in the scientific community and among decision makers regarding the risks and benefits of using these products [...].
Collapse
|