Cell culture systems reproducing virus replication can serve as unique models for the discovery of novel bioactive molecules. Here, using a hepatitis C virus (HCV) cell culture system, we identified neoechinulin B (NeoB), a fungus-derived compound, as an inhibitor of the liver X receptor (LXR). NeoB was initially identified by chemical screening as a compound that impeded the production of infectious HCV. Genome-wide transcriptome analysis and reporter assays revealed that NeoB specifically inhibits LXR-mediated transcription. NeoB was also shown to interact directly with LXRs. Analysis of structural analogs suggested that the molecular interaction of NeoB with LXR correlated with the capacity to inactivate LXR-mediated transcription and to modulate lipid metabolism in hepatocytes. Our data strongly suggested that NeoB is a novel LXR antagonist. Analysis using NeoB as a bioprobe revealed that LXRs support HCV replication: LXR inactivation resulted in dispersion of double-membrane vesicles, putative viral replication sites. Indeed, cells treated with NeoB showed decreased replicative permissiveness for poliovirus, which also replicates in double-membrane vesicles, but not for dengue virus, which replicates via a distinct membrane compartment. Together, our data suggest that LXR-mediated transcription regulates the formation of virus-associated membrane compartments. Significantly, inhibition of LXRs by NeoB enhanced the activity of all known classes of anti-HCV agents, and NeoB showed especially strong synergy when combined with interferon or an HCV NS5A inhibitor. Thus, our chemical genetics analysis demonstrates the utility of the HCV cell culture system for identifying novel bioactive molecules and characterizing the virus-host interaction machinery.IMPORTANCEHepatitis C virus (HCV) is highly dependent on host factors for efficient replication. In the present study, we used an HCV cell culture system to screen an uncharacterized chemical library. Our results identified neoechinulin B (NeoB) as a novel inhibitor of the liver X receptor (LXR). NeoB inhibited the induction of LXR-regulated genes and altered lipid metabolism. Intriguingly, our results indicated that LXRs are critical to the process of HCV replication: LXR inactivation by NeoB disrupted double-membrane vesicles, putative sites of viral replication. Moreover, NeoB augmented the antiviral activity of all known classes of currently approved anti-HCV agents without increasing cytotoxicity. Thus, our strategy directly links the identification of novel bioactive compounds to basic virology and the development of new antiviral agents.

Background: Following percutaneous coronary intervention (PCI), optical coherence tomography provides prognosis information. The pullback pressure gradient is a novel index that discriminates focal from diffuse coronary artery disease based on fractional flow reserve pullbacks. We sought to investigate the association between coronary artery disease patterns, defined by coronary physiology, and optical coherence tomography after stent implantation in stable patients undergoing PCI. Methods and Results: This multicenter, prospective, single‐arm study was conducted in 5 countries (NCT03782688). Subjects underwent motorized fractional flow reserve pullbacks evaluation followed by optical coherence tomography‐guided PCI. Post‐PCI optical coherence tomography minimum stent area, stent expansion, and the presence of suboptimal findings such as incomplete stent apposition, stent edge dissection, and irregular tissue protrusion were compared between patients with focal versus diffuse disease. Overall, 102 patients (105 vessels) were included. Fractional flow reserve before PCI was 0.65±0.14, pullback pressure gradient was 0.66±0.14, and post‐PCI fractional flow reserve was 0.88±0.06. The mean minimum stent area was 5.69±1.99 mm ² and was significantly larger in vessels with focal disease (6.18±2.12 mm ² versus 5.19±1.72 mm ² , P =0.01). After PCI, incomplete stent apposition, stent edge dissection, and irregular tissue protrusion were observed in 27.6%, 10.5%, and 51.4% of the cases, respectively. Vessels with focal disease at baseline had a lower prevalence of incomplete stent apposition (11.3% versus 44.2%, P =0.002) and more irregular tissue protrusion (69.8% versus 32.7%, P <0.001). Conclusions: Baseline coronary pathophysiological patterns are associated with suboptimal imaging findings after PCI. Patients with focal disease had larger minimum stent area and a higher incidence of tissue protrusion, whereas stent malapposition was more frequent in patients with diffuse disease.

BACKGROUND: Coronary computed tomography angiography (CCTA) is emerging as a valuable tool for noninvasive surveillance of cardiac allograft vasculopathy (CAV) in patients with heart transplant (HTx). We assessed the diagnostic performance of a comprehensive CCTA-based approach compared with the invasive reference, which includes invasive coronary angiography, intravascular ultrasound, and fractional flow reserve, for detecting CAV. METHODS: This was a multicenter prospective study including 37 patients with HTx who underwent CCTA, invasive coronary angiography, intravascular ultrasound, and fractional flow reserve. The comprehensive CCTA-based approach included quantitative and qualitative plaque analysis and functional assessment by fractional flow reserve derived from coronary computed tomography. CAV was diagnosed based on invasive coronary angiography (International Society for Heart and Lung Transplantation criteria) and intravascular ultrasound. Univariable logistic regression analysis was performed to test CCTA-derived predictors of CAV. The area under the curve and accuracy indicators were calculated to evaluate the performance and best cutoffs of CCTA predictors of CAV. RESULTS: The median interval between CCTA and HTx was 5 years. Among the 37 recipients, 23 (62.2%) were diagnosed with CAV. The integration of diameter stenosis and plaque morphology (including plaque burden at minimum lumen area >42% and percent atheroma volume >23%) at CCTA yielded the highest diagnostic performance (accuracy, 84%; sensitivity, 83%; specificity, 86%). The integration of ∆fractional flow reserve derived from coronary computed tomography trans-vessel gradient led to increased sensitivity, albeit with decreased specificity and overall accuracy. The noninvasive approach was associated with a lower contrast and radiation dose, compared with the invasive approach. CONCLUSIONS: A noninvasive strategy based on CCTA is accurate for managing patients with HTx. CCTA might be considered the preferred imaging modality for annual CAV surveillance after the first year post-HTx.

Background: In patients presenting with acute coronary syndromes (ACS), impaired coronary blood flow (CBF) after percutaneous coronary interventions (PCI) is linked to mortality. We developed a novel angiography‐based approach for blood flow quantification using automatic contrast bolus tracking. Therefore, this study aimed to investigate the clinical impact of angiography‐based blood flow quantification on major adverse cardiovascular events (MACE) after PCI in patients with ACS. Methods: Prospective, multicenter, nested case–control study of patients presenting ACS. A propensity score was used to match patients with and without MACE at 1 year of follow‐up. MACE was defined as cardiovascular death, myocardial infarction, hospitalization for heart failure, or ischemia‐driven revascularization. CBF was measured automatically from angiograms after PCI. Results: One hundred sixty‐two patients were included. The mean age was 68.3±13.0 years, 83% were male, and 33% had diabetes. Overall, 66% of patients presented with ST‐segment–elevation myocardial infarction. CBF after PCI was lower after ST‐segment–elevation myocardial infarction compared with other clinical presentations (74.1±47.0 mL/min ST‐segment–elevation myocardial infarction, 89.1±45.8 mL/min, non‐ST‐segment–elevation myocardial infarction, 95.7±48.8 mL/min, unstable angina, P =0.046). Patients with low post‐PCI CBF (<54.3 mL/min) had an increased risk of MACE (hazard ratio, 2.11 [95% CI, 1.35–3.28], P =0.001). Conclusions: After PCI, automatic quantification of CBF using angiography was associated with MACE in patients with ACS. Risk stratification using post‐PCI CBF‐derived angiography may enable tailored management strategies for individuals with ACS.

Severe calcified lesions are difficult to assess using conventional coronary computed tomography angiography (CCTA). Artificial intelligence (AI)-driven reconstruction may help address this limitation. A 93-year-old man with angina underwent AI-enhanced high-resolution CCTA using the Aquilion ONE/INSIGHT Edition (Canon Medical Systems). The AI-enhanced imaging clearly revealed severe eccentric calcification from the distal left main trunk to the proximal left anterior descending artery. Intravascular ultrasound confirmed this finding. Percutaneous coronary intervention (PCI) was performed with orbital atherectomy, cutting balloon predilation, and drug-eluting stent implantation, achieving good stent expansion. AI-enhanced CCTA enabled the accurate visualization and measurement of calcified plaques, including their arc and thickness, facilitating the selection of appropriate devices and lesion preparation for PCI. AI-enhanced CCTA provides precise evaluation of severely calcified coronary plaques. It guides PCI strategy by accurately assessing calcium burden and plaque morphology.