Vaping Perpetuates Cardiac Electrical Instability

ABSTRACTBackgroundTobacco cigarette smoking is on the decline, but the usage of electronic nicotine delivery systems (ENDS) is gaining popularity, specifically in the teen and young adult age groups. While the cardiac toxicity of tobacco cigarette smoking has been widely studied and is well established, the possible cardiac toxicity of ENDS products and their design characteristics, such as added flavorings, are largely underexplored. Vaping, a form of electronic nicotine delivery, uses “e-liquid” to generate “e-vapor”, a smoke-like aerosolized mixture of nicotine and flavors. Here, we tested the hypothesis that vaping results in cardiac electrophysiological instability and arrhythmogenesis. We thus investigated how e-liquids with different flavors affect cardiac in-vitro and in-vivo toxicity, in cell culture and in animals.MethodsThree e-liquids with vanilla, cinnamon or fruit flavors were studied. We quantified apoptosis and oxygen consumption rate in HL-1 cells cultured with e-vapors extracts. In human iPSC derived ventricular cardiomyocytes (hiPSC-CM) cultured with e-vapor extract, beating frequency and repolarization duration were measured using multiple electrode arrays (MEA). Mass spectrometry (GC-MS) was used to analyze the composition of the e-vapors. Telemetric ECGs were obtained in freely moving C57BL/6J mice exposed to vanilla flavored e-vapor for 10 weeks and heart rate variability was analyzed (HRV). In-vivo inducibility of ventricular tachycardia as well as optical mapping of voltage in isolated Langendorff-perfused hearts were also carried out.ResultsE-vapor caused a dose dependent increase in toxicity in Hl-1 myocytes and e-vapors containing vanilla and cinnamon flavorings, as indicated by GC-MS, were more toxic, and inhibited cellular respiration more than the fruit flavored e-vapor. In hiPSC-CM cultured with 25% cinnamon flavored e-vapor for 24 hours, beating frequency increased, and the field potential duration significantly increased compared to air control. Inhalation exposure to vanilla flavored e-vapor for 10 weeks caused significant effects on HRV. Additionally, inducible VT was significantly longer, and in optical mapping, the magnitude of ventricular action potential duration alternans was significantly larger in the exposed mice compared to controlConclusionThe widely popular flavored ENDS are not harm free, and they show potential toxicity to the heart, in-vitro, and in vivo. Further studies are needed to further assess their cardiac safety profile, and long-term health effects.

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In vitro and in vivo cardiac toxicity of flavored electronic nicotine delivery systems

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00283.2020 ◽

2021 ◽

Vol 320 (1) ◽

pp. H133-H143

Author(s):

Obada Abouassali ◽

Mengmeng Chang ◽

Bojjibabu Chidipi ◽

Jose Luis Martinez ◽

Michelle Reiser ◽

...

Keyword(s):

Ventricular Arrhythmias ◽

Cardiac Electrophysiology ◽

Cardiac Toxicity ◽

Delivery Systems ◽

Cardiac Safety ◽

Electronic Nicotine Delivery Systems ◽

Nicotine Delivery

The use of electronic nicotine delivery systems (ENDS) is not harm free. It is not known whether ENDS negatively affect cardiac electrophysiological function. Our study in cell lines and in mice shows that ENDS can compromise cardiac electrophysiology, leading to action potential instability and inducible ventricular arrhythmias. Further investigations are necessary to assess the long-term cardiac safety profile of ENDS products in humans and to better understand how individual components of ENDS affect cardiac toxicity.

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Carbon dioxide inhalation causes pulmonary inflammation

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.90460.2008 ◽

2009 ◽

Vol 296 (4) ◽

pp. L657-L665 ◽

Cited By ~ 32

Author(s):

Mohammad Abolhassani ◽

Adeline Guais ◽

Philippe Chaumet-Riffaud ◽

Annie J. Sasco ◽

Laurent Schwartz

Keyword(s):

Carbon Dioxide ◽

Nuclear Translocation ◽

Rnase Protection Assay ◽

Airway Hyperreactivity ◽

Cellular Respiration ◽

Rnase Protection ◽

Monocyte Chemoattractant Protein 1 ◽

Enhanced Production

The aim of this study was to assess whether one of the most common poisons of cellular respiration, i.e., carbon dioxide, is proinflammatory. CO2 is naturally present in the atmosphere at the level of 0.038% and involved in numerous cellular biochemical reactions. We analyzed in vitro the inflammation response induced by exposure to CO2 for 48 h (0–20% with a constant O2 concentration of 21%). In vivo mice were submitted to increasing concentrations of CO2 (0, 5, 10, and 15% with a constant O2 concentration of 21%) for 1 h. The exposure to concentrations above 5% of CO2 resulted in the increased transcription (RNase protection assay) and secretion (ELISA) of proinflammatory cytokines [macrophage inflammatory protein-1α (MIP-1α), MIP-1β, MIP-2, IL-8, IL-6, monocyte chemoattractant protein-1, and regulated upon activation, normal T cell expressed, and, presumably, secreted (RANTES)] by epithelial cell lines HT-29 or A549 and primary pulmonary cells retrieved from the exposed mice. Lung inflammation was also demonstrated in vivo by mucin 5AC-enhanced production and airway hyperreactivity induction. This response was mostly mediated by the nuclear translocation of p65 NF-κB, itself a consequence of protein phosphatase 2A (PP2A) activation. Short inhibiting RNAs (siRNAs) targeted toward PP2Ac reversed the effect of carbon dioxide, i.e., disrupted the NF-κB activation and the proinflammatory cytokine secretion. In conclusion, this study strongly suggests that exposure to carbon dioxide may be more toxic than previously thought. This may be relevant for carcinogenic effects of combustion products.

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PRO-INFLAMMATORY MOLECULAR AND INFLAMMATORY MECHANISMS OF SULFUR METABOLISM IN IBD-RELEVANT CLOSTRIDIA SPECIES

Inflammatory Bowel Diseases ◽

10.1093/ibd/izaa347.072 ◽

2021 ◽

Vol 27 (Supplement_1) ◽

pp. S30-S31

Author(s):

Gabriel Suarez ◽

Bo Liu ◽

Jeremy Herzog ◽

Ryan Sartor

Keyword(s):

Sulfur Metabolism ◽

Cellular Respiration ◽

Bile Acid Metabolism ◽

Bile Salt Hydrolase ◽

Oxygen Binding ◽

Bacterial Strains ◽

Healthy Human ◽

H2s Production

Abstract Sulfur metabolism is emerging as a signature of IBD gut microbiota. Overrepresentation of sulfur-reducing bacteria (SRB) in IBD results in SRB-derived epithelial toxic H2S production that can overwhelm the body’s detoxification capacity, leading to impaired cellular respiration by inhibiting oxygen binding to mitochondrial cytochrome-c-oxidase. Butyrate potently inhibits SRBs and H2S, yet IBD patients have reduced short chain fatty acid (SCFA) production. More critically, H2S blocks butyrate oxidation, the primary energy source of colonocytes; butyrate oxidation deficiency is a defining characteristic of IBD. Since cysteine is the preferred substrate for H2S production by SRBs, a cysteine-rich environment provided by either a high protein diet or local intestinal mucus degradation promotes ideal conditions for SRB establishment and proliferation. SRBs can catabolize other sulfur-containing compounds critical for immune homeostasis and cellular health, such as taurine-conjugated bile acids and the “master antioxidant” glutathione, leading to further toxic H2S production. However, the molecular underpinnings of sulfur metabolism by specific bacterial genera is understudied in IBD. Results: Using a combination of in-vivo and in-vitro screening to detect the relative induction of interleukin 10 (IL-10) and interferon g (IFNg) by 19 resident bacterial strains isolated from a healthy human donor, we identified 4 bacterial strains that induce a low IL-10/IFNg ratio. These 4 strains (low group), but not 3 bacterial strains that induce a high IL-10/IFNg ratio, induce colitis in selectively colonized gnotobiotic Il10-/- mice (Fig.1A). Two of these 4 disease-inducing strains, Clostridium perfringens (A12) and Clostridium bolteae (B6), produce high concentrations of H2S in monoassociated mice (Fig.1B). In-vitro H2S production by these strains is dependent on cysteine (Fig.1C). C. perfringens and C. bolteae each induce colitis in monoassociated Il10-/- mice (Fig.1D). We are dissecting the sulfur metabolic pathways in C. perfringens and C. bolteae and their contribution to inflammatory processes by interrupting key genes predicted to contribute to H2S production, cysteine catabolism and bile acid metabolism. We will use these mutants in both in-vitro and in-vivo Il10 -/- gnotobiotic mice models to characterize their metabolic and inflammatory profiles. We have created several mutants using Targetron gene editing, including the dissimilatory sulfate reductase (Δdsr), a putative sulfonate membrane transporter (ΔssuA), anaerobic sulfite reductase (ΔasrA) and bile salt hydrolase (Δbsh). Conclusions: H2S producing bacterial strains can induce experimental colitis. Our planned mechanistic studies will determine the metabolic routes for H2S production by specific aggressive bacteria to guide novel therapeutic or dietary interventions to improve IBD prognosis.

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Inhibitory effects of Panax ginseng glycoproteins in models of doxorubicin-induced cardiac toxicity in vivo and in vitro

Food & Function ◽

10.1039/d1fo01307f ◽

2021 ◽

Author(s):

Yajun Chen ◽

Lei Wang ◽

Tianjia Liu ◽

Zhidong Qiu ◽

Ye Qiu ◽

...

Keyword(s):

Oxidative Stress ◽

Protective Effect ◽

Cell Viability ◽

Panax Ginseng ◽

Cardiac Toxicity ◽

H9c2 Cell ◽

Inhibitory Effects ◽

Myocardial Oxidative Stress

We investigated the protective effect of PGP against DOX-induced cardiotoxicity in vitro and in vivo. PGP increases H9C2 cell viability and inhibits apoptosis, alleviating DOX-induced myocardial oxidative stress-related cardiotoxicity.

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Abstract 418: Caveolar Disruption of L-type Calcium Channel and Ryanodine Receptor Facilitates Atrial Ectopy and Arrhythmogenesis in Heart Failure Mice

Circulation Research ◽

10.1161/res.127.suppl_1.418 ◽

2020 ◽

Vol 127 (Suppl_1) ◽

Author(s):

Di Lang ◽

Lucas ratajczyk ◽

Leonid Tyan ◽

Daniel Turner ◽

Francisco Alvarado ◽

...

Keyword(s):

Heart Failure ◽

Optical Mapping ◽

Ryanodine Receptors ◽

Tissue Level ◽

Confocal Imaging ◽

Right Atrial ◽

Isolated Atria ◽

The Right

Atrial fibrillation (AF) often occurs during heart failure (HF). Ectopic foci that trigger AF, are linked to discrete atrial regions that experience the highest remodeling and clinically used for AF ablation; however, mechanisms of their arrhythmogenic propensity remain elusive. We employed in vivo ECG telemetry, in vitro optical mapping and confocal imaging of Ca 2+ transients (CaT) from myocytes isolated from the right atrial appendage (RAA) and inter-caval region (ICR) of wild type (WT, n=10), caveolin-3 knockout (KO, n=6) and 8-weeks post-myocardial infarction HF (n=8) mice. HF and KO mice showed an increased susceptibility to pacing-induced AF and enhanced ectopy originated exclusively from ICR. Optical mapping in isolated atria showed prolongation of CaT rise up time (CaT-RT) in HF ICR, which suggested a remodeled coupling between L-type Ca 2+ channels (LTCCs) and ryanodine receptors (RyRs) in this specific region. In WT mice, RAA consists of structured myocytes with a prominent transverse-axial tubular system (TATS) while ICR myocytes don’t have TATS. In RAA, CaT-RT depends on LTCCs in TATS triggering RyR, while in ICR, all the LTCCs are localized in surface caveolae where they can activate subsarcolemmal RyRs and lead to a slow diffusion of Ca 2+ inside the cell interior. Downregulation of caveolae was observed specifically in HF ICR. To mimic this, we used cav3-KO mice. Triggered activities were observed in myocytes isolated from HF and KO ICR, which presumably underlie the ectopic activities in tissue level. These myocytes presented significantly unsynchronized sarcoplasmic reticulum (SR) Ca 2+ releases (synchronization index: 10.8±0.9 in WT vs 38.3±4.1 in HF vs 21.5±2.1 in KO, p <0.01 for HF and KO vs WT respectively) especially at the subsarcolemmal space that prolongs CaT-RT (62.2±4.1 ms in WT vs 122.5±12.8 ms in KO, p <0.01). In addition, failing ICR myocytes showed a higher occurrence and size of spontaneous Ca 2+ sparks which were linked to CaMKII activity and associated phosphorylation of RyR. Our findings demonstrate that in HF, caveolar disruption creates “hot spots” for arrhythmogenic ectopic activity emanated from discrete vulnerable regions of the right atrium which are associated with desynchronized SR Ca 2+ release and elevated fibrosis.

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Effect of Glutathione and N-Acetylcysteine on in Vitro and in VIVO Cardiac Toxicity of Doxorubicin

Free Radical Research Communications ◽

10.3109/10715769009109677 ◽

1990 ◽

Vol 11 (1-3) ◽

pp. 145-151 ◽

Cited By ~ 17

Author(s):

Fabrizio Villani ◽

Milena Galimberti ◽

Elena Monti ◽

Francesco Piccinini ◽

Enrica Lanza ◽

...

Keyword(s):

Cardiac Toxicity

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In Vitro Models, Standards, and Experimental Methods for Tobacco Products

Advances in Dental Research ◽

10.1177/0022034519872474 ◽

2019 ◽

Vol 30 (1) ◽

pp. 16-21 ◽

Cited By ~ 3

Author(s):

T. Aghaloo ◽

J.J. Kim ◽

T. Gordon ◽

H.P. Behrsing

Keyword(s):

Cigarette Smoking ◽

Electronic Cigarettes ◽

Testing Machine ◽

The United States ◽

In Vitro Models ◽

In Vivo Studies ◽

Tobacco Products ◽

Direct Exposure

Traditional tobacco products have well-known systemic and local oral effects, including inflammation, vasoconstriction, delayed wound healing, and increased severity of periodontal disease. Specifically in the oral cavity and the lung, cigarette smoking produces cancer, increased infectivity, acute and chronic inflammation, changes in gene expression in epithelial lining cells, and microbiome changes. In recent years, cigarette smoking has greatly decreased in the United States, but the use of new tobacco products has gained tremendous popularity. Without significant knowledge of the oral sequelae of products such as electronic cigarettes, researchers must evaluate current in vitro and in vivo methods to study these agents, as well as develop new tools to adequately study their effects. Some in vitro testing has been performed for electronic cigarettes, including toxicologic models and assays, but these mostly study the effect on the respiratory tract. Recently, direct exposure of the aerosol to in vitro 3-dimensional tissue constructs has been performed, demonstrating changes in cell viability and inflammatory cytokines. For in vivo studies, a universal e-cigarette testing machine or standard vaping regime is needed. A standard research electronic cigarette has recently been developed by the National Institute of Drug Abuse, and other devices delivering aerosols with different nicotine concentrations are becoming available. One of the biggest challenges in this research is keeping up with the new products and the rapidly changing technologies in the industry.

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PIN*POINT analysis on the endogenous MnSOD promoter: specific demonstration of Sp1 binding in vivo

AJP Cell Physiology ◽

10.1152/ajpcell.00356.2002 ◽

2003 ◽

Vol 284 (2) ◽

pp. C528-C534 ◽

Cited By ~ 7

Author(s):

Shiuhyang Kuo ◽

Ann L. Chokas ◽

Richard J. Rogers ◽

Harry S. Nick

Keyword(s):

Binding Sites ◽

Manganese Superoxide Dismutase ◽

Consensus Sequence ◽

Dimethyl Sulfate ◽

Site Directed Mutagenesis ◽

Cellular Respiration ◽

Point Analysis ◽

Specific Regulation

Manganese superoxide dismutase (MnSOD) is a critical antioxidant enzyme that protects against superoxide anion generated as a consequence of normal cellular respiration, as well as during the inflammatory response. By employing dimethyl sulfate in vivo footprinting, we have previously identified ten basal protein binding sites within the MnSODpromoter. On the basis of consensus sequence comparison and in vitro footprinting data, one would predict that Sp1 might occupy five of these binding sites. To address these findings in the context of the nucleoprotein environment, we first utilized chromatin immunoprecipitation (ChIP) to demonstrate the nuclear association of Sp1 with the MnSOD promoter region. To identify the precise location of Sp1 binding, we have modified the original protein position identification with nuclease tail (PIN*POINT) methodology, providing an approach to establish both the identity and binding occupancy of Sp1 in the context of the endogenous MnSOD promoter. These data, coupled with site-directed mutagenesis, demonstrate the functional importance of two of the Sp1 binding sites in the stimulus-specific regulation of MnSOD gene expression. We feel that the combination of ChIP and PIN*POINT analysis allows unequivocal identification and localization of protein/DNA interactions in vivo, specifically the demonstration of Sp1 with the MnSODpromoter.

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