Epithelial Dual Oxidase 2 Shapes the Mucosal Microbiome and Contributes to Inflammatory Susceptibility.

Reactive oxygen species (ROS) are highly reactive molecules formed from diatomic oxygen. They act as cellular signals, exert antibiotic activity towards invading microorganisms, but can also damage host cells. Dual oxidase 2 (DUOX2) is the main ROS-producing enzyme in the intestine, regulated by cues of the commensal microbiota and functions in pathogen defense. DUOX2 plays multiple roles in different organs and cell types, complicating the functional analysis using systemic deletion models. Here, we interrogate the precise role of epithelial DUOX2 for intestinal homeostasis and host-microbiome interactions. Conditional Duox2∆IEC mice lacking DUOX2, specifically in intestinal epithelial cells, were generated, and their intestinal mucosal immune phenotype and microbiome were analyzed. Inflammatory susceptibility was evaluated by challenging Duox2∆IEC mice in the dextran sodium sulfate (DSS) colitis model. DUOX2-microbiome interactions in humans were investigated by paired analyses of mucosal DUOX2 expression and fecal microbiome data in patients with intestinal inflammation. Under unchallenged conditions, we did not observe any obvious phenotype of Duox2∆IEC mice, although intestinal epithelial ROS production was drastically decreased, and the mucosal microbiome composition was altered. When challenged with DSS, Duox2∆IEC mice were protected from colitis, possibly by inhibiting ROS-mediated damage and fostering epithelial regenerative responses. Finally, in patients with intestinal inflammation, DUOX2 expression was increased in inflamed tissue, and high DUOX2 levels were linked to a dysbiotic microbiome. Our findings demonstrate that bidirectional DUOX2-microbiome interactions contribute to mucosal homeostasis, and their dysregulation may drive disease development, thus highlighting this axis as a therapeutic target to treat intestinal inflammation.

Spanish cardiac catheterization and coronary intervention registry. 32nd official report of the Interventional Cardiology Association of the Spanish Society of Cardiology (1990-2022).

INTRODUCTION AND OBJECTIVES: This article presents the annual activity report of the Interventional Cardiology Association of the Spanish Society of Cardiology (ACI-SEC) for the year 2022. METHODS: All Spanish centers with catheterization laboratories were invited to participate. Data were collected online and were analyzed by an external company in collaboration with the members of the board of the ACI-SEC. RESULTS: A total of 111 centers participated. The number of diagnostic studies increased by 4.8% compared with 2021, while that of percutaneous coronary interventions (PCI) remained stable. PCIs on the left main coronary artery increased by 22%. The radial approach continued to be preferred for PCI (94.9%). There was an upsurge in the use of drug-eluting balloons, as well as in intracoronary imaging techniques, which were used in 14.7% of PCIs. The use of pressure wires also increased (6.3% vs 2021) as did plaque modification techniques. Primary PCI continued to grow and was the most frequent treatment (97%) in ST-segment elevation myocardial infarction. Most noncoronary procedures maintained their upward trend, particularly percutaneous aortic valve implantation, atrial appendage closure, mitral/tricuspid edge-to-edge therapy, renal denervation, and percutaneous treatment of pulmonary arterial disease. CONCLUSIONS: The Spanish cardiac catheterization and coronary intervention registry for 2022 reveals a rise in the complexity of coronary disease, along with a notable growth in procedures for valvular and nonvalvular structural heart disease.

Symptomatic vs. non-symptomatic device-related thrombus after LAAC: a sub-analysis from the multicenter EUROC-DRT registry.

BACKGROUND: Device-related thrombus (DRT) after left atrial appendage closure (LAAC) is associated with adverse outcomes, i.e. ischemic stroke or systemic embolism (SE). Data on predictors of stroke/SE in the context of DRT are limited. AIMS: This study aimed to identify predisposing factors for stroke/SE in DRT patients. In addition, the temporal connection of stroke/SE to DRT diagnosis was analyzed. METHODS: The EUROC-DRT registry included 176 patients, in whom DRT after LAAC were diagnosed. Patients with symptomatic DRT, defined as stroke/SE in the context of DRT diagnosis, were compared against patients with non-symptomatic DRT. Baseline characteristics, anti-thrombotic regimens, device position, and timing of stroke/SE were compared. RESULTS: Stroke/SE occurred in 25/176 (14.2%) patients diagnosed with DRT (symptomatic DRT). Stroke/SE occurred after a median of 198 days (IQR 37-558) after LAAC. In 45.8% stroke/SE occurred within one month before/after DRT diagnosis (DRT-related stroke). Patients with symptomatic DRT had lower left ventricular ejection fractions (50.0 ± 9.1% vs. 54.2 ± 11.0%, p = 0.03) and higher rates of non-paroxysmal atrial fibrillation (84.0% vs. 64.9%, p = 0.06). Other baseline parameters and device positions were not different. Most ischemic events occurred among patients with single antiplatelet therapy (50%), however, stroke/SE was also observed under dual antiplatelet therapy (25%) or oral anticoagulation (20%). CONCLUSION: Stroke/SE are documented in 14.2% and occur both in close temporal relation to the DRT finding and chronologically independently therefrom. Identification of risk factors remains cumbersome, putting all DRT patients at substantial risk for stroke/SE. Further studies are necessary to minimize the risk of DRT and ischemic events.

Clinical and echocardiographic risk factors for device-related thrombus after left atrial appendage closure: an analysis from the multicenter EUROC-DRT registry.

BACKGROUND: Data on Device-related Thrombus (DRT) after left atrial appendage closure (LAAC) remain scarce. This study aimed to investigate risk factors for DRT from centers reporting to the EUROC-DRT registry. METHODS: We included 537 patients (112 with DRT and 425 without DRT) who had undergone LAAC between 12/2008 and 04/2019. Baseline and implantation characteristics, anti-thrombotic treatment and clinical outcomes were compared between both groups in uni- and multivariate analyses. Additional propensity-score matching (PSM) was conducted to focus on the role of implantation characteristics. RESULTS: Patients with DRT showed higher rates of previous stroke/transient ischemic attack (TIA) (49.1% vs. 34.7%, p < 0.01), spontaneous echocardiographic contrast (SEC) (44.9% vs. 27.7%, p < 0.01) and lower left atrial appendage (LAA) peak emptying velocity (35.4 ± 18.5 vs. 42.4 ± 18.0 cm/s, p = 0.02). Occluders implanted in DRT patients were larger (25.5 ± 3.8 vs. 24.6 ± 3.5 mm, p = 0.03) and implanted deeper in the LAA (mean depth: 7.6 ± 4.7 vs. 5.7 ± 4.7 mm, p < 0.01). Coverage of the appendage ostium was achieved less often in DRT patients (69.5% vs. 81.5%, p < 0.01), while DRT patients were less frequently on oral anticoagulation (7.1% vs. 16.7%, p < 0.01). Multivariate analysis identified age, prior stroke/TIA and SEC as independent risk factors for DRT. After PSM, implantation depth was found to be predictive. Rates of stroke/TIA were higher in DRT patients (13.5% vs. 3.8%, Hazard Ratio: 4.21 [95%-confidence interval: 1.88-9.49], p < 0.01). CONCLUSIONS: DRT after LAAC is associated with adverse outcome and appears to be of multifactorial origin, depending on patient characteristics, anticoagulation regimen and device position.

Dual RNA Sequencing of Mycobacterium tuberculosis-Infected Human Splenic Macrophages Reveals a Strain-Dependent Host-Pathogen Response to Infection.

Tuberculosis (TB) is caused by Mycobacterium tuberculosis (Mtb), leading to pulmonary and extrapulmonary TB, whereby Mtb is disseminated to many other organs and tissues. Dissemination occurs early during the disease, and bacteria can be found first in the lymph nodes adjacent to the lungs and then later in the extrapulmonary organs, including the spleen. The early global gene expression response of human tissue macrophages and intracellular clinical isolates of Mtb has been poorly studied. Using dual RNA-seq, we have explored the mRNA profiles of two closely related clinical strains of the Latin American and Mediterranean (LAM) family of Mtb in infected human splenic macrophages (hSMs). This work shows that these pathogens mediate a distinct host response despite their genetic similarity. Using a genome-scale host-pathogen metabolic reconstruction to analyze the data further, we highlight that the infecting Mtb strain also determines the metabolic response of both the host and pathogen. Thus, macrophage ontogeny and the genetic-derived program of Mtb direct the host-pathogen interaction.

TCA Cycle and Its Relationship with Clavulanic Acid Production: A Further Interpretation by Using a Reduced Genome-Scale Metabolic Model of Streptomyces clavuligerus.

Streptomyces clavuligerus (S. clavuligerus) has been widely studied for its ability to produce clavulanic acid (CA), a potent inhibitor of ß-lactamase enzymes. In this study, S. clavuligerus cultivated in 2D rocking bioreactor in fed-batch operation produced CA at comparable rates to those observed in stirred tank bioreactors. A reduced model of S. clavuligerus metabolism was constructed by using a bottom-up approach and validated using experimental data. The reduced model was implemented for in silico studies of the metabolic scenarios arisen during the cultivations. Constraint-based analysis confirmed the interrelations between succinate, oxaloacetate, malate, pyruvate, and acetate accumulations at high CA synthesis rates in submerged cultures of S. clavuligerus. Further analysis using shadow prices provided a first view of the metabolites positive and negatively associated with the scenarios of low and high CA production.

Prevalence, mechanisms and impact of residual patency and device-related thrombosis following left atrial appendage occlusion: a computed tomography analysis.

BACKGROUND: Cardiac computed tomography angiography (CCTA) appears to be an appropriate imaging technique for device surveillance after left atrial appendage occlusion (LAAO). However, the available experience is limited. AIMS: The aim of this study was to determine the prevalence, mechanisms and clinical impact of left atrial appendage (LAA) patency and device-related thrombosis (DRT) following LAAO utilising a novel CCTA-based classification. METHODS: Consecutively enrolled patients who underwent LAAO with an AMPLATZER device were followed up with CCTA. Mechanisms and frequency of residual patency were evaluated and correlated with clinical events. Atrial-side device thrombus, device positioning and presence of signs of device stability were also analysed. RESULTS: A total of 137 patients were included. LAA patency was observed in 56.9% (n=78). Mechanisms and frequency of patency were: malapposition of proximal segment of the device lobe (55.1%), peri-device leak (PDL, 34.6%) and fabric permeability (5.8%). Lobe-LAA axis misalignment was the only independent predictor of device patency after LAAO (HR 38.3, 95% CI: 13.6-107.0; p<0.001). After a median follow-up of 638 days, patency was not associated with an increased risk of death (all-cause or cardiovascular death) or cerebral/peripheral embolism regardless of its mechanism. Any degree of hypo-attenuated thickening (HAT) was found in 16.8% (n=23) of patients, of whom 16 (11.7%) had low-grade HAT and 7 (5.1%) had high-grade HAT or definite DRT. Complete sealing was associated with increased rates of low-grade HAT. CONCLUSIONS: LAA patency on CCTA follow-up is a frequent phenomenon due to malapposition of the proximal segment of the device lobe, PDL or fabric permeability. Patency was not associated with adverse outcomes. Low-grade HAT may be related to a benign, uneventful, endothelialisation process favoured by complete LAAO.

Device-Related Thrombus After Left Atrial Appendage Closure: Data on Thrombus Characteristics, Treatment Strategies, and Clinical Outcomes From the EUROC-DRT-Registry.

BACKGROUND: Left atrial appendage closure is an established therapy in patients with atrial fibrillation. Although device-related thrombosis (DRT) is relatively rare, it is potentially linked to adverse events. As data on DRT characteristics, outcome, and treatment regimen are scarce, we aimed to assess these questions in a multicenter approach. METHODS: One hundred fifty-six patients with the diagnosis of DRT after left atrial appendage closure were included in the multinational EUROC-DRT registry. Baseline characteristics included clinical and echocardiographic data. After inclusion, all patients underwent further clinical and echocardiographic follow-up to assess DRT dynamics, treatment success, and outcome. RESULTS: DRT was detected after a median of 93 days (interquartile range, 54­161 days) with 17.9% being detected >6 months after left atrial appendage closure. Patients with DRT were at high ischemic and bleeding risk (CHA2DS2-VASc 4.5±1.7, HAS-BLED 3.3±1.2) and had nonparoxysmal atrial fibrillation (67.3%), previous stroke (53.8%), and spontaneous echo contrast (50.6%). The initial treatment regimens showed comparable resolution rates (antiplatelet monotherapy: 57.1%, dual antiplatelet therapy: 85.7%, vitamin K antagonists: 80.0%, novel oral anticoagulants: 75.0%, and heparin: 68.6%). After intensification or switch of treatment, complete DRT resolution was achieved in 79.5% of patients. Two-year follow-up revealed a high risk of mortality (20.0%) and ischemic stroke (13.8%) in patients with DRT. Patients with incomplete DRT resolution showed numerically higher stroke rates and increased mortality rates (stroke: 17.6% versus 12.3%, P=0.29; mortality: 31.3% versus 13.1%, P=0.05). CONCLUSIONS: A substantial proportion of DRT is detected >6 months after left atrial appendage closure, highlighting the need for imaging follow-up. Patients with DRT appear to be at a high risk for stroke and mortality. While DRT resolution was achieved in most patients, incomplete DRT resolution appeared to identify patients at even higher risk. Optimal DRT diagnostic criteria and treatment regimens are warranted.

Clavulanic Acid Production by Streptomyces clavuligerus: Insights from Systems Biology, Strain Engineering, and Downstream Processing.

Clavulanic acid (CA) is an irreversible ß-lactamase enzyme inhibitor with a weak antibacterial activity produced by Streptomyces clavuligerus (S. clavuligerus). CA is typically co-formulated with broad-spectrum ß­lactam antibiotics such as amoxicillin, conferring them high potential to treat diseases caused by bacteria that possess ß­lactam resistance. The clinical importance of CA and the complexity of the production process motivate improvements from an interdisciplinary standpoint by integrating metabolic engineering strategies and knowledge on metabolic and regulatory events through systems biology and multi-omics approaches. In the large-scale bioprocessing, optimization of culture conditions, bioreactor design, agitation regime, as well as advances in CA separation and purification are required to improve the cost structure associated to CA production. This review presents the recent insights in CA production by S. clavuligerus, emphasizing on systems biology approaches, strain engineering, and downstream processing.

Reducción de los ingresos por infarto agudo de miocardio con elevación del segmento ST en Cataluña durante la pandemia de COVID-19 / Decrease in ST-segment elevation myocardial infarction admissions in Catalonia during the COVID-19 pandemic

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A Genome-Scale Insight into the Effect of Shear Stress During the Fed-Batch Production of Clavulanic Acid by Streptomyces Clavuligerus.

Streptomyces clavuligerus is a filamentous Gram-positive bacterial producer of the ß-lactamase inhibitor clavulanic acid. Antibiotics biosynthesis in the Streptomyces genus is usually triggered by nutritional and environmental perturbations. In this work, a new genome scale metabolic network of Streptomyces clavuligerus was reconstructed and used to study the experimentally observed effect of oxygen and phosphate concentrations on clavulanic acid biosynthesis under high and low shear stress. A flux balance analysis based on experimental evidence revealed that clavulanic acid biosynthetic reaction fluxes are favored in conditions of phosphate limitation, and this is correlated with enhanced activity of central and amino acid metabolism, as well as with enhanced oxygen uptake. In silico and experimental results show a possible slowing down of tricarboxylic acid (TCA) due to reduced oxygen availability in low shear stress conditions. In contrast, high shear stress conditions are connected with high intracellular oxygen availability favoring TCA activity, precursors availability and clavulanic acid (CA) production.

Impact of the CHA2DS2-VASc score on late clinical outcomes in patients undergoing left atrial appendage occlusion.

BACKGROUND: Left atrial appendage occlusion (LAAO) is an accepted strategy for cardioembolic events prevention in patients with non-valvular atrial fibrillation (AF) unsuitable for anticoagulation. However, uncertainties persist regarding the benefit of LAAO in highly-comorbid patients. The aim of this study was to assess the impact of the CHA2DS2-VASc score beyond thromboembolic risk in predicting clinical outcomes in patients undergoing LAAO. METHODS: 160 patients who underwent LAAO were included and categorized into two groups according to their stroke risk (89 with CHA2DS2-VASc >4 vs. 71 with lower risk). The coprimary endpoints were death and stroke at follow-up. Thromboembolic and bleeding events were compared to those predicted from CHA2DS2-VASc and HAS-BLED scores. RESULTS: Over a median follow-up of 679 days, CHA2DS2-VASc >4 was associated with increased all-cause mortality compared with patients with lower thromboembolic risk (HR: 3.23; 95% CI: 1.28-8.19; p < 0.001). However, the rates of stroke after LAAO were not significantly different between risk groups. The observed annual rates of stroke and major bleeding were lower than predicted. CONCLUSIONS: Despite increased long-term mortality in patients with CHA2DS2-VASc >4, LAAO remains beneficial in reducing stroke and bleeding events in high-risk AF patients unsuitable for anticoagulation.

A systematic evaluation of Mycobacterium tuberculosis Genome-Scale Metabolic Networks.

Metabolism underpins the pathogenic strategy of the causative agent of TB, Mycobacterium tuberculosis (Mtb), and therefore metabolic pathways have recently re-emerged as attractive drug targets. A powerful approach to study Mtb metabolism as a whole, rather than just individual enzymatic components, is to use a systems biology framework, such as a Genome-Scale Metabolic Network (GSMN) that allows the dynamic interactions of all the components of metabolism to be interrogated together. Several GSMNs networks have been constructed for Mtb and used to study the complex relationship between the Mtb genotype and its phenotype. However, the utility of this approach is hampered by the existence of multiple models, each with varying properties and performances. Here we systematically evaluate eight recently published metabolic models of Mtb-H37Rv to facilitate model choice. The best performing models, sMtb2018 and iEK1011, were refined and improved for use in future studies by the TB research community.

Bioresorbable vascular scaffolds in coronary chronic total occlusions: clinical, vasomotor and optical coherence tomography findings at three-year follow-up (ABSORB-CTO study).

AIMS: Percutaneous treatment of coronary chronic total occlusion (CTO) is associated with important arterial remodelling after successful recanalisation. Bioresorbable vascular scaffold (BVS) implantation in CTO has been shown to be feasible and can be of interest when the scaffold achieves complete bioresorption. We sought to evaluate the three-year results in terms of clinical events, serial imaging outcomes and vasomotion response in CTO lesions successfully treated with BVS. METHODS AND RESULTS: A total of 33 patients (35 CTO lesions) successfully treated with BVS were included in the ABSORB-CTO study. Clinical outcomes, quantitative coronary angiography (QCA) and optical coherence tomography (OCT) assessment were analysed at one- and three-year follow-up. Vasomotion examination was also performed at three years. At three years, cumulative target vessel reocclusion was observed in four lesions (11.4%). By QCA, the in-scaffold segment presented a lumen loss of 0.23±0.46 mm compared with the baseline procedure (p=0.001) and a lumen gain of 0.05±0.29 mm between one and three years (p=0.220). By OCT, the mean neointimal area stenosis progressed from 11.45% at 12 months to 17.10% at 36 months (p<0.001) and mean scaffold area increased continuously at 12 (+12%; p<0.001) and at 36 months (+14.85%; p=0.001). Late acquired incomplete scaffold apposition (LAISA) observed at 12 months in three patients was completely undetectable at three years. Most cases responded to endothelium-dependent vasomotor stimuli (69%). Vasoconstriction to acetylcholine was the predominant response (45%). CONCLUSIONS: Successful recanalisation of coronary CTO with BVS implantation is associated with favourable clinical and imaging outcomes. Despite vessel motility restoration, successfully treated CTOs remain with signs of endothelial dysfunction.

Metabolic adaptation of two in silico mutants of Mycobacterium tuberculosis during infection.

BACKGROUND: Up to date, Mycobacterium tuberculosis (Mtb) remains as the worst intracellular killer pathogen. To establish infection, inside the granuloma, Mtb reprograms its metabolism to support both growth and survival, keeping a balance between catabolism, anabolism and energy supply. Mtb knockouts with the faculty of being essential on a wide range of nutritional conditions are deemed as target candidates for tuberculosis (TB) treatment. Constraint-based genome-scale modeling is considered as a promising tool for evaluating genetic and nutritional perturbations on Mtb metabolic reprogramming. Nonetheless, few in silico assessments of the effect of nutritional conditions on Mtb's vulnerability and metabolic adaptation have been carried out. RESULTS: A genome-scale model (GEM) of Mtb, modified from the H37Rv iOSDD890, was used to explore the metabolic reprogramming of two Mtb knockout mutants (pfkA- and icl-mutants), lacking key enzymes of central carbon metabolism, while exposed to changing nutritional conditions (oxygen, and carbon and nitrogen sources). A combination of shadow pricing, sensitivity analysis, and flux distributions patterns allowed us to identify metabolic behaviors that are in agreement with phenotypes reported in the literature. During hypoxia, at high glucose consumption, the Mtb pfkA-mutant showed a detrimental growth effect derived from the accumulation of toxic sugar phosphate intermediates (glucose-6-phosphate and fructose-6-phosphate) along with an increment of carbon fluxes towards the reductive direction of the tricarboxylic acid cycle (TCA). Furthermore, metabolic reprogramming of the icl-mutant (icl1&icl2) showed the importance of the methylmalonyl pathway for the detoxification of propionyl-CoA, during growth at high fatty acid consumption rates and aerobic conditions. At elevated levels of fatty acid uptake and hypoxia, we found a drop in TCA cycle intermediate accumulation that might create redox imbalance. Finally, findings regarding Mtb-mutant metabolic adaptation associated with asparagine consumption and acetate, succinate and alanine production, were in agreement with literature reports. CONCLUSIONS: This study demonstrates the potential application of genome-scale modeling, flux balance analysis (FBA), phenotypic phase plane (PhPP) analysis and shadow pricing to generate valuable insights about Mtb metabolic reprogramming in the context of human granulomas.