Differential inflammatory profile in the lungs of mice exposed to cannabis smoke with varying THC:CBD ratio.

Cannabis contains cannabinoids including Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD). THC causes the psychoactive effects of cannabis, and both THC and CBD are thought to be anti-inflammatory. Cannabis is typically consumed by inhaling smoke that contains thousands of combustion products that may damage the lungs. However, the relationship between cannabis smoke exposure and alterations in respiratory health is poorly defined. To address this gap in knowledge, we first developed a mouse model of cannabis smoke exposure using a nose-only rodent inhalation exposure system. We then tested the acute effects of two dried cannabis products that differ substantially in their THC-CBD ratio: Indica-THC dominant (I-THC; 16-22% THC) and Sativa-CBD dominant (S-CBD; 13-19% CBD). We demonstrate that this smoke exposure regime not only delivers physiologically relevant levels of THC to the bloodstream, but that acute inhalation of cannabis smoke modulates the pulmonary immune response. Cannabis smoke decreased the percentage of lung alveolar macrophages but increased lung interstitial macrophages (IMs). There was also a decrease in lung dendritic cells as well as Ly6Cintermediate and Ly6Clow monocytes, but an increase in lung neutrophils and CD8+ T cells. These immune cell changes were paralleled with changes in several immune mediators. These immunological modifications were more pronounced when mice were exposed to S-CBD compared to the I-THC variety. Thus, we show that acute cannabis smoke differentially affects lung immunity based on the THC:CBD ratio, thereby providing a foundation to further explore the effect of chronic cannabis smoke exposures on pulmonary health.

Chronic low-level JUUL aerosol exposure causes pulmonary immunologic, transcriptomic, and proteomic changes.

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.

Receptor-mediated effects of Δ9 -tetrahydrocannabinol and cannabidiol on the inflammatory response of alveolar macrophages.

Δ9 -Tetrahydrocannabinol (Δ9 -THC) and cannabidiol (CBD) are cannabinoids found in Cannabis sativa. While research supports cannabinoids reduce inflammation, the consensus surrounding receptor(s)-mediated effects has yet to be established. Here, we investigated the receptor-mediated properties of Δ9 -THC and CBD on alveolar macrophages, an important pulmonary immune cell in direct contact with cannabinoids inhaled by cannabis smokers. MH-S cells, a mouse alveolar macrophage cell line, were exposed to Δ9 -THC and CBD, with and without lipopolysaccharide (LPS). Outcomes included RNA-sequencing and cytokine analysis. Δ9 -THC and CBD alone did not affect the basal transcriptional response of MH-S cells. In response to LPS, Δ9 -THC and CBD significantly reduced the expression of numerous proinflammatory cytokines including tumor necrosis factor-alpha, interleukin (IL)-1ß and IL-6, an effect that was dependent on CB2 . The anti-inflammatory effects of CBD but not Δ9 -THC were mediated through a reduction in signaling through nuclear factor-kappa B and extracellular signal-regulated protein kinase 1/2. These results suggest that CBD and Δ9 -THC have potent immunomodulatory properties in alveolar macrophages, a cell type important in immune homeostasis in the lungs. Further investigation into the effects of cannabinoids on lung immune cells could lead to the identification of therapies that may ameliorate conditions characterized by inflammation.

Rotational atherectomy of calcified coronary lesions: current practice and insights from two randomized trials.

With growing experience, technical improvements and use of newer generation drug-eluting stents (DES), recent data showed satisfactory acute and long-term results after rotational atherectomy (RA) in calcified coronary lesions. The randomized ROTAXUS and PREPARE-CALC trials compared RA to balloon-based strategies in two different time periods in the DES era. In this manuscript, we assessed the technical evolution in RA practice from a pooled analysis of the RA groups of both trials and established a link to further recent literature. Furthermore, we sought to summarize and analyze the available experience with RA in different patient and lesion subsets, and propose recommendations to improve RA practice. We also illustrated the combination of RA with other methods of lesion preparation. Finally, based on the available evidence, we propose a simple and practical approach to treat severely calcified lesions.

Combined rotational atherectomy and cutting balloon angioplasty prior to drug-eluting stent implantation in severely calcified coronary lesions: The PREPARE-CALC-COMBO study.

OBJECTIVES: To evaluate the safety and efficacy of lesion preparation using rotational atherectomy (RA) with consecutive cutting balloon angioplasty (Rota-Cut). BACKGROUND: Whether the Rota-Cut combination improves stent performance in severely calcified coronary lesions is unknown. METHODS: PREPARE-CALC-COMBO is a single-arm prospective trial in which 110 patients were treated with a Rota-Cut strategy before implantation of sirolimus-eluting stents and compared with patients treated with modified balloon (MB, scoring or cutting) or RA from a historical cohort (the randomized PREPARE-CALC trial). The study had two primary endpoints: in-stent acute lumen gain (ALG) by quantitative angiographic analysis and stent expansion (SE) on optical coherence tomography. RESULTS: In-stent ALG was significantly higher with Rota-Cut compared to RA or MB alone (1.92 ± 0.45 mm vs. 1.74 ± 0.45 mm with MB vs. 1.70 ± 0.42 mm with RA; p = 0.001 and p < 0.001, respectively). SE was comparable between groups (75.1 ± 13.8% vs. 73.5 ± 13.3 with MB vs. 73.1 ± 12.2 with RA; p = 0.19 and p = 0.39, respectively). The Rota-Cut combination resulted in higher minimal stent area (MSA) (7.1 ± 2.2mm2 vs. 6.1 ± 1.7mm2  with MB vs. 6.2 ± 1.9mm2 with RA; p = 0.003 and p = 0.004, respectively). In-hospital death occurred in one patient. Target vessel failure at 9 months was low and comparable between groups (8.2% vs. 8% with MB vs. 6% with RA; p = 1 and p = 0.79, respectively). CONCLUSION: Rota-Cut combination resulted in higher ALG and larger MSA compared with historical control of RA or MB alone, but was not associated with higher SE. Despite extensive lesion preparation, this strategy is safe, feasible, and associated with favorable clinical outcome at 9 months.

Standardized Cannabis Smoke Extract Induces Inflammation in Human Lung Fibroblasts.

Cannabis (marijuana) is the most commonly used illicit product in the world and is the second most smoked plant after tobacco. There has been a rapid increase in the number of countries legalizing cannabis for both recreational and medicinal purposes. Smoking cannabis in the form of a joint is the most common mode of cannabis consumption. Combustion of cannabis smoke generates many of the same chemicals as tobacco smoke. Although the impact of tobacco smoke on respiratory health is well-known, the consequence of cannabis smoke on the respiratory system and, in particular, the inflammatory response is unclear. Besides the combustion products present in cannabis smoke, cannabis also contains cannabinoids including Δ9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD). These compounds are hydrophobic and not present in aqueous solutions. In order to understand the impact of cannabis smoke on pathological mechanisms associated with adverse respiratory outcomes, the development of in vitro surrogates of cannabis smoke exposure is needed. Therefore, we developed a standardized protocol for the generation of cannabis smoke extract (CaSE) to investigate its effect on cellular mechanisms in vitro. First, we determined the concentration of Δ9-THC, one of the major cannabinoids, by ELISA and found that addition of methanol to the cell culture media during generation of the aqueous smoke extract significantly increased the amount of Δ9-THC. We also observed by LC-MS/MS that CaSE preparation with methanol contains CBD. Using a functional assay in cells for CB1 receptors, the major target of cannabinoids, we found that this CaSE contains Δ9-THC which activates CB1 receptors. Finally, this standardized preparation of CaSE induces an inflammatory response in human lung fibroblasts. This study provides an optimized protocol for aqueous CaSE preparation containing biologically active cannabinoids that can be used for in vitro experimentation of cannabis smoke and its potential impact on various indices of pulmonary health.

Differential impact of JUUL flavors on pulmonary immune modulation and oxidative stress responses in male and female mice.

JUUL is a popular e-cigarette brand that manufactures e-liquids in a variety of flavors, such as mango and mint. Despite their popularity, the pulmonary effects of flavored JUUL e-liquids that are aerosolized and subsequently inhaled are not known. Therefore, the purpose of this study was to evaluate if acute exposure to JUUL e-cigarette aerosols in three popular flavors elicits an immunomodulatory or oxidative stress response in mice. We first developed a preclinical model that mimics human use patterns of e-cigarettes using 1 puff/min or 4 puffs/min exposure regimes. Based on cotinine levels, these exposures were representative of light/occasional and moderate JUUL users. We then exposed C57BL/6 mice to JUUL e-cigarette aerosols in mango, mint, and Virginia tobacco flavors containing 5% nicotine for 3 days, and assessed the inflammatory and oxidative stress response in the lungs and blood. In response to the 1 puff/min regime (light/occasional user), there were minimal changes in BAL cell composition or lung mRNA expression. However, at 4 puffs/min (moderate user), mint-flavored JUUL significantly increased lung neutrophils, while mango-flavored JUUL significantly increased Tnfα and Il13 mRNA in the lungs. Both the 1- and 4 puffs/min regimes significantly increased oxidative stress markers in the blood, indicating systemic effects. Thus, JUUL products are not inert; even short-term inhalation of flavored JUUL e-cigarette aerosols differentially causes immune modulation and oxidative stress responses.

Endogenous regulation of the Akt pathway by the aryl hydrocarbon receptor (AhR) in lung fibroblasts.

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor known to mediate toxic responses to dioxin. However, the role of the AhR in the regulation of cellular physiology has only recently been appreciated, including its ability to control cell cycle progression and apoptosis by unknown mechanisms. We hypothesized that the AhR enhances the activation of the AKT serine/threonine kinase (Akt) pathway to promote cell survival. Utilizing AhR knock-out (Ahr-/-) and wild-type (Ahr+/+) mouse lung fibroblasts (MLFs), we found that Ahr-/- MLFs have significantly higher basal Akt phosphorylation but that AhR did not affect Akt phosphorylation in MLFs exposed to growth factors or AhR ligands. Basal Akt phosphorylation was dependent on PI3K but was unaffected by changes in intracellular glutathione (GSH) or p85α. There was no significant decrease in cell viability in Ahr-/- MLFs treated with LY294002-a PI3K inhibitor-although LY294002 did attenuate MTT reduction, indicating an affect on mitochondrial function. Using a mass spectrometry (MS)-based approach, we identified several proteins that were differentially phosphorylated in the Ahr-/- MLFs compared to control cells, including proteins involved in the regulation of extracellular matrix (ECM), focal adhesion, cytoskeleton remodeling and mitochondrial function. In conclusion, Ahr ablation increased basal Akt phosphorylation in MLFs. Our results indicate that AhR may modulate the phosphorylation of a variety of novel proteins not previously identified as AhR targets, findings that help advance our understanding of the endogenous functions of AhR.

Differential Regulation of the Asthmatic Phenotype by the Aryl Hydrocarbon Receptor.

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that regulates the metabolism of xenobiotics. There is growing evidence that the AhR is implicated in physiological processes such proliferation, differentiation, and immune responses. Recently, a role of the AhR in regulating allergic asthma has been suggested, but whether the AhR also regulates other type of asthma, particularly occupational/irritant-induced asthma, remains unknown. Using AhR-deficient (Ahr-/- ) mice, we compared the function of the AhR in the response to ovalbumin (OVA; allergic asthma) vs. chlorine (Cl2; irritant-induced asthma) exposure. Lung inflammation and airway hyperresponsiveness were assessed 24h after exposure to Cl2 or OVA challenge in Ahr-/- and heterozygous (Ahr+/- ) mice. After OVA challenge, absence of AhR was associated with significantly enhanced eosinophilia and lymphocyte influx into the airways of Ahr-/- mice. There were also increased levels of interleukin-4 (IL-4) and IL-5 in the airways. However, OVA-induced airway hyperresponsiveness was not affected. In the irritant-induced asthma model caused by exposure to Cl2, the AhR did not regulate the inflammatory response. However, absence of AhR reduced Cl2-induced airway hyperresponsiveness. Collectively, these results support a differential role for the AhR in regulating asthma outcomes in response to diverse etiological agents.

Feasibility and safety of minimal-contrast IVUS-guided rotational atherectomy for complex calcified coronary artery disease.

OBJECTIVES: To assess the feasibility and safety of minimal-contrast percutaneous coronary intervention (PCI) using rotational atherectomy (RA) in patients with severe coronary calcification at high-risk of contrast-associated acute kidney injury (AKI). METHODS: Twenty-six patients with advanced chronic kidney disease undergoing PCI with RA at three high-volume centres were included. Baseline intravascular ultrasound (IVUS) was performed to assess lesion morphology, and to guide burr-, balloon-, and stent-selection. Final result was assessed by IVUS and angiographically. Feasibility and safety were determined by procedural and in-hospital complications, and efficacy was assessed by freedom from contrast-associated AKI after PCI. Procedural and in-hospital outcome was compared to a propensity-matched population of standard RA PCI. RESULTS: Mean glomerular filtration rate was 32 ± 17 ml/min/1.73 m2. In seven cases PCI was performed in the setting of acute coronary syndrome. The left main coronary artery was treated in 27.8% and a two-stent bifurcation technique in 44.4%. RA was more often performed electively compared to the standard RA cohort (92.3 vs. 50%; p = 0.0016). Angiographic success was achieved in 100% and documented with a median contrast amount of 12.5 ml [Range 4-43]. No in-hospital death or myocardial infarction was reported. Contrast-associated AKI occurred in one patient versus five patients in standard RA group (p = 0.19). Shorter fluoroscopy time and lower radiation dose were achieved as compared to standard RA. CONCLUSION: A minimal-contrast RA approach with IVUS-guidance for treatment of complex calcified coronary lesions is feasible and safe with high success rate.

Outcomes of patients treated with a biodegradable-polymer sirolimus-eluting stent versus durable-polymer everolimus-eluting stents after rotational atherectomy.

OBJECTIVE: To compare Orsiro biodegradable-polymer sirolimus-eluting stent (Orsiro BP-SES) with durable-polymer everolimus-eluting stent (DP-EES) regarding target lesion failure (TLF) after rotational atherectomy (RA), with a focus on small stents (diameter ≤ 3 mm) where Orsiro BP-SES has 60 µm strut thickness, while DP-EES remains with 81 µm strut thickness. BACKGROUND: New-generation drug-eluting stent (DES) is superior to early-generation DES in all percutaneous coronary intervention (PCI) settings including RA. Recently, the Orsiro BP-SES was superior to a DP-EES in an all comer's population. METHODS: Among patients who underwent RA at a single center, 121 were treated with Orsiro BP-SES and 164 with DP-EES (Promus and Xience). Those treated with other stent types, presenting with acute myocardial infarction or had a chronic total occlusion were excluded. Incidence of TLF was assessed. RESULTS: After 2 years, the TLF rate in Orsiro BP-SES and DP-EES groups was 10% and 18%, respectively (adjusted HR 0.55, 95%CI 0.26-1.16, p = 0.115). The rate of TLF was significantly lower in small Orsiro BP-SES with ultra-thin struts as compared to DP-EES with the same diameters (adjusted HR 0.19, 95% CI 0.04-0.87, p = 0.032), driven by lower rates of clinically driven target lesion revascularization (log-rank p = 0.022). Age (p = 0.035), total stent length (p = 0.007) and diabetes mellitus (p = 0.011) emerged as independent predictors of TLF in the whole population. CONCLUSION: In the whole cohort, Orsiro BP-SES and DP-EES had comparable rates of long-term TLF after RA. In the small stent subgroup, the Orsiro BP-SES with ultra-thin struts showed significant lower rate of TLF at 2 years.

Human antigen R promotes lung fibroblast differentiation to myofibroblasts and increases extracellular matrix production.

Idiopathic pulmonary fibrosis (IPF) is a disease of progressive scarring caused by excessive extracellular matrix (ECM) deposition and activation of α-SMA-expressing myofibroblasts. Human antigen R (HuR) is an RNA binding protein that promotes protein translation. Upon translocation from the nucleus to the cytoplasm, HuR functions to stabilize messenger RNA (mRNA) to increase protein levels. However, the role of HuR in promoting ECM production, myofibroblast differentiation, and lung fibrosis is unknown. Human lung fibroblasts (HLFs) treated with transforming growth factor ß1 (TGF-ß1) showed a significant increase in translocation of HuR from the nucleus to the cytoplasm. TGF-ß-treated HLFs that were transfected with HuR small interfering RNA had a significant reduction in α-SMA protein as well as the ECM proteins COL1A1, COL3A, and FN1. HuR was also bound to mRNA for ACTA2, COL1A1, COL3A1, and FN. HuR knockdown affected the mRNA stability of ACTA2 but not that of the ECM genes COL1A1, COL3A1, or FN. In mouse models of pulmonary fibrosis, there was higher cytoplasmic HuR in lung structural cells compared to control mice. In human IPF lungs, there was also more cytoplasmic HuR. This study is the first to show that HuR in lung fibroblasts controls their differentiation to myofibroblasts and consequent ECM production. Further research on HuR could assist in establishing the basis for the development of new target therapy for fibrotic diseases, such as IPF.

The Aryl Hydrocarbon Receptor Attenuates Acute Cigarette Smoke-Induced Airway Neutrophilia Independent of the Dioxin Response Element.

Cigarette smoke is a prevalent respiratory toxicant that remains a leading cause of death worldwide. Cigarette smoke induces inflammation in the lungs and airways that contributes to the development of diseases such as lung cancer and chronic obstructive pulmonary disease (COPD). Due to the presence of aryl hydrocarbon receptor (AhR) ligands in cigarette smoke, activation of the AhR has been implicated in driving this inflammatory response. However, we have previously shown that the AhR suppresses cigarette smoke-induced pulmonary inflammation, but the mechanism by which the AhR achieves its anti-inflammatory function is unknown. In this study, we use the AhR antagonist CH-223191 to inhibit AhR activity in mice. After an acute (3-day) cigarette smoke exposure, AhR inhibition was associated with significantly enhanced neutrophilia in the airways in response to cigarette smoke, mimicking the phenotype of AhR-deficient mice. We then used genetically-modified mouse strains which express an AhR that can bind ligand but either cannot translocate to the nucleus or bind its cognate response element, to show that these features of the AhR pathway are not required for the AhR to suppress pulmonary neutrophilia. Finally, using the non-toxic endogenous AhR ligand FICZ, we provide proof-of-concept that activation of pulmonary AhR attenuates smoke-induced inflammation. Collectively, these results support the importance of AhR activity in mediating its anti-inflammatory function in response to cigarette smoke. Further investigation of the precise mechanisms by which the AhR exerts is protective functions may lead to the development of therapeutic agents to treat people with chronic lung diseases that have an inflammatory etiology, but for which few therapeutic options exist.

Aryl hydrocarbon receptor deficiency causes the development of chronic obstructive pulmonary disease through the integration of multiple pathogenic mechanisms.

Emphysema, a component of chronic obstructive pulmonary disease (COPD), is characterized by irreversible alveolar destruction that results in a progressive decline in lung function. This alveolar destruction is caused by cigarette smoke, the most important risk factor for COPD. Only 15%-20% of smokers develop COPD, suggesting that unknown factors contribute to disease pathogenesis. We postulate that the aryl hydrocarbon receptor (AHR), a receptor/transcription factor highly expressed in the lungs, may be a new susceptibility factor whose expression protects against COPD. Here, we report that Ahr-deficient mice chronically exposed to cigarette smoke develop airspace enlargement concomitant with a decline in lung function. Chronic cigarette smoke exposure also increased cleaved caspase-3, lowered SOD2 expression, and altered MMP9 and TIMP-1 levels in Ahr-deficient mice. We also show that people with COPD have reduced expression of pulmonary and systemic AHR, with systemic AHR mRNA levels positively correlating with lung function. Systemic AHR was also lower in never-smokers with COPD. Thus, AHR expression protects against the development of COPD by controlling interrelated mechanisms involved in the pathogenesis of this disease. This study identifies the AHR as a new, central player in the homeostatic maintenance of lung health, providing a foundation for the AHR as a novel therapeutic target and/or predictive biomarker in chronic lung disease.

The Aryl Hydrocarbon Receptor Suppresses Chronic Smoke-Induced Pulmonary Inflammation.

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor expressed in the lungs that is activated by numerous xenobiotic, endogenous and dietary ligands. Although historically the AhR is known for mediating the deleterious response to the environmental pollutant dioxin, emerging evidence supports a prominent role for the AhR in numerous biological process including inflammation. We have shown that the AhR suppresses pulmonary neutrophilia in response to acute cigarette smoke exposure. Whether the AhR can also prevent lung inflammation from chronic smoke exposure is not known but highly relevant, given that people smoke for decades. Using our preclinical smoke model, we report that exposure to chronic cigarette smoke for 8-weeks or 4 months significantly increased pulmonary inflammation, the response of which was greater in Ahr -/- mice. Notably, there was an increased number of multinucleated giant cells (MNGCs) in smoke-exposed Ahr -/- mice without a change in cytokine levels. These data support a protective role for the AhR against the deleterious effects of cigarette smoke, warranting continued investigation into its therapeutic potential for chronic lung diseases.

Angiotensin-converting enzyme 2 expression in COPD and IPF fibroblasts: the forgotten cell in COVID-19.

The COVID-19 pandemic is associated with severe pneumonia and acute respiratory distress syndrome leading to death in susceptible individuals. For those who recover, post-COVID-19 complications may include development of pulmonary fibrosis. Factors contributing to disease severity or development of complications are not known. Using computational analysis with experimental data, we report that idiopathic pulmonary fibrosis (IPF)- and chronic obstructive pulmonary disease (COPD)-derived lung fibroblasts express higher levels of angiotensin-converting enzyme 2 (ACE2), the receptor for SARS-CoV-2 entry and part of the renin-angiotensin system that is antifibrotic and anti-inflammatory. In preclinical models, we found that chronic exposure to cigarette smoke, a risk factor for both COPD and IPF and potentially for SARS-CoV-2 infection, significantly increased pulmonary ACE2 protein expression. Further studies are needed to understand the functional implications of ACE2 on lung fibroblasts, a cell type that thus far has received relatively little attention in the context of COVID-19.

The aryl hydrocarbon receptor reduces LC3II expression and controls endoplasmic reticulum stress.

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor whose physiological function is poorly understood. The AhR is highly expressed in barrier organs such as the skin, intestine, and lung. The lungs are continuously exposed to environmental pollutants such as cigarette smoke (CS) that can induce cell death mechanisms such as apoptosis, autophagy, and endoplasmic reticulum (ER) stress. CS also contains toxicants that are AhR ligands. We have previously shown that the AhR protects against apoptosis, but whether the AhR also protects against autophagy or ER stress is not known. Using cigarette smoke extract (CSE) as our in vitro surrogate of environmental tobacco exposure, we first assessed the conversion of LC3I to LC3II, a classic feature of both autophagic and ER stress-mediated cell death pathways. LC3II was elevated in CSE-exposed lung structural cells [mouse lung fibroblasts (MLFs), MLE12 and A549 cells] when AhR was absent. However, this heightened LC3II expression could not be explained by increased expression of key autophagy genes (Gabarapl1, Becn1, Map1lc3b), upregulation of upstream autophagic machinery (Atg5-12, Atg3), or impaired autophagic flux, suggesting that LC3II may be autophagy independent. This was further supported by the absence of autophagosomes in Ahr-/- lung cells. However, Ahr-/- lung cells had widespread ER dilation, elevated expression of the ER stress markers CHOP and GADD34, and an accumulation of ubiquitinated proteins. These findings collectively illustrate a novel role for the AhR in attenuating ER stress by a mechanism that may be autophagy independent.

Impact of Lesion Preparation Technique on Side Branch Compromise in Calcified Coronary Bifurcations: A Subgroup Analysis of the PREPARE-CALC Trial.

OBJECTIVES: To analyze the impact of different techniques of lesion preparation of severely calcified coronary bifurcation lesions. BACKGROUND: The impact of different techniques of lesion preparation of severely calcified coronary bifurcation lesions is poorly investigated. METHODS: We performed an as-treated analysis on 47 calcified bifurcation lesions treated with scoring/cutting balloons (SCB) and 68 lesions treated with rotational atherectomy (RA) in the PREPARE-CALC trial. Compromised side branch (SB) as assessed in the final angiogram was the primary outcome measure and was defined as any significant stenosis, dissection, or thrombolysis in myocardial infarction flow <3. RESULTS: True bifurcation lesions were present in 49% vs. 43% of cases in the SCB and RA groups, respectively. After stent implantation, SB balloon dilatation was necessary in around one-third of cases (36% vs. 38%; p = 0.82), and a two-stent technique was performed in 21.3% vs. 25% (p = 0.75). At the end of the procedure, the SB remained compromised in 15 lesions (32%) in the SCB group and 5 lesions (7%) in the RA group (p = 0.001). Large coronary dissections were more frequently observed in the SCB group (13% vs. 2%; p = 0.02). Postprocedural levels of cardiac biomarkers were significantly higher in patients with a compromised SB at the end of the procedure. CONCLUSIONS: In the PREPARE-CALC trial, side branch compromise was more frequently observed after lesion preparation with SCB as compared with RA. Consequently, in calcified bifurcation lesions, an upfront debulking with an RA-based strategy might optimize the result in the side branch.

Inhalation Toxicology of Vaping Products and Implications for Pulmonary Health.

E-cigarettes have a liquid that may contain flavors, solvents, and nicotine. Heating this liquid generates an aerosol that is inhaled into the lungs in a process commonly referred to as vaping. E-cigarette devices can also contain cannabis-based products including tetrahydrocannabinol (THC), the psychoactive component of cannabis (marijuana). E-cigarette use has rapidly increased among current and former smokers as well as youth who have never smoked. The long-term health effects are unknown, and emerging preclinical and clinical studies suggest that e-cigarettes may not be harmless and can cause cellular alterations analogous to traditional tobacco smoke. Here, we review the historical context and the components of e-cigarettes and discuss toxicological similarities and differences between cigarette smoke and e-cigarette aerosol, with specific reference to adverse respiratory outcomes. Finally, we outline possible clinical disorders associated with vaping on pulmonary health and the recent escalation of acute lung injuries, which led to the declaration of the vaping product use-associated lung injury (EVALI) outbreak. It is clear there is much about vaping that is not understood. Consequently, until more is known about the health effects of vaping, individual factors that need to be taken into consideration include age, current and prior use of combustible tobacco products, and whether the user has preexisting lung conditions such as asthma and chronic obstructive pulmonary disease (COPD).

Coronary Access After TAVR With a Self-Expanding Bioprosthesis: Insights From Computed Tomography.

OBJECTIVES: The authors sought to estimate possible interference of the Medtronic Evolut R/Pro transcatheter heart valve (THV) frame with coronary access using multislice computed tomography (MSCT) data. BACKGROUND: Lower-risk patients undergoing transcatheter aortic valve replacement (TAVR) endure a high cumulative risk of coronary events, but coronary access can be challenging. METHODS: In 101 patients who received an Evolut R/Pro THV, post-TAVR MSCT (performed at a median of 30 days after TAVR) was used to assess possible interference of the elements of the THV frame with coronary access. RESULTS: The closest cell of the THV frame vertically aligned with the coronary ostium was located opposite the ostium in 58% and 63%, below the ostium in 22% and 30%, or above the ostium in 20% and 7% of left and right coronary arteries, respectively. The free sinus of Valsalva space between the THV frame and the coronary ostium was 0.45 ± 0.17 cm and 0.44 ± 0.17 cm for the left and right coronary arteries, respectively, and showed a stepwise decrease with decreasing THV size (p < 0.001). Bioprosthetic valve commissures were antianatomic (i.e., not aligned with native commissures) in 45 patients (47%), and the commissural post was overlapping a coronary ostium in 15 patients (16%). Two patients (2.0%) had a possible interference of the paravalvular sealing skirt with coronary access. CONCLUSIONS: Using post-TAVR MSCT data, the main mechanism of potential interference of Evolut R/Pro frame with coronary access was an antianatomic commissural post overlapping the coronary ostium.