CRISPR/Cas9 Mediated Deletion of the Uox Gene Generates a Mouse Model of Hyperuricemia with Multiple Complications.

Hyperuricemia is a common metabolic disorder with severe complications. We aimed to develop a mouse model for spontaneous hyperuricemia. Uox-/- mouse model was generated on C57BL/6J background by deleting exon 2-4 of Uox using the CRISPR/Cas9 system. The prototypic Uox -/-mice had 5.5-fold increased serum uric acid (1351.04±276.58µmol/L) as compared to the wild type mice (P<0.0001), but died by 4 weeks. After allopurinol (3ug/g) intervention, they all survived > 8 weeks. The serum uric acid was 612.55±146.98µmol/L in the 8-week-old allopurinol-rescued Uox -/-mice, which manifested multiple complications including severe renal insufficiency, hypertension, left ventricular remodeling and systolic dysfunction, aortic endothelial dysfunction, hepatic steatosis and elevated liver enzymes, as well as hyperglycemia and hypercholesteremia. The present Uox-/- mice developed spontaneous hyperuricemia complicated with urate nephropathy, cardiovascular disease and cardiometabolic disorders, and may provide a novel tool to study hyperuricemia associated early-onset cardiovascular disorders in human.

Triglyceride-glucose index is associated with severe obstructive coronary artery disease and atherosclerotic target lesion failure among young adults.

BACKGROUND: Early diagnosis and treatment effectiveness of early-onset coronary artery disease (EOCAD) are crucial, and non-invasive predictive biomarkers are needed for young adults. We aimed to evaluate the usefulness of the triglyceride-glucose (TyG) index, a novel marker of insulin resistance, in identifying young CAD patients and predicting their risk of developing target lesion failure (TLF). METHODS: We recruited EOCAD patients (luminal narrowing ≥ 70%) and controls free from CAD (luminal narrowing < 30%), both aged 45 years or younger, from 38 hospitals in China between 2017 and 2020. EOCAD patients who underwent successful percutaneous coronary intervention were followed for incident TLF. TyG index was defined as Ln [fasting triglyceride (mg/dL) × fasting blood glucose (mg/dL)/2]. We used logistic regression and Cox proportional hazards modeling to evaluate the association of TyG index with prevalent EOCAD and incident TLF, respectively. The discriminatory ability of TyG index was assessed by the area under the receiver-operating characteristic curve (AUC). RESULTS: Among the included 1513 EOCAD patients (39.6 ± 4.4 years, 95.4% male) and 1513 age-matched controls (39.0 ± 4.4 years, 46.4% male), TyG index was positively associated with the prevalence of EOCAD (adjusted odds ratio: 1.40, 95% confidence interval [CI] 1.23-1.60, per standard deviation [SD] increase in TyG index). The addition of TyG index to an empirical risk model provided an improvement in diagnostic ability for EOCAD, with a net reclassification improvement of 0.10 (95% CI 0.03-0.17, p = 0.005). During a medium of 33 month (IQR: 31-34 months) follow-up, 43 (3.3%) patients experienced TLF. Multivariate Cox regression model revealed that TyG index was an independent risk factor for TLF (adjusted hazard ratio [HR]: 2.410, 95% CI 1.07-5.42 comparing the top to bottom TyG index tertile groups; HR: 1.30, 95% CI 1.01-1.73, per SD increase in TyG index). Compared with a model of conventional risk factors alone, the addition of the TyG index modestly improved the AUC (0.722-0.734, p = 0.04) to predict TLF. CONCLUSIONS: TyG index is positively associated with prevalent EOCAD and incident TLF. TyG index appeared to be a valuable component of future efforts to improve CAD risk stratification and TLF outcome prediction among young adults.

Current of injury is an indicator of lead depth and performance during left bundle branch pacing lead implantation.

BACKGROUND: Monitoring of lead depth is crucial to achieve left bundle branch pacing (LBBP) with a low capture threshold and avoid septal perforation, but lacks informative approach. OBJECTIVE: We aimed to prospectively assess the predictive value of current of injury on the occurrence of inadequate left bundle branch (LBB) capture threshold and acute septal perforation. METHODS: Consecutive patients who received LBBP were enrolled. ST-segment elevation ≥ 25% of intrinsic R-wave amplitude on the unipolar intracardiac electrogram was defined as a sign of distinct current of injury. An LBB capture threshold of <1.5 V/0.5 ms was considered acceptable. RESULTS: LBBP was attempted 513 times in 212 patients. The LBB capture threshold was more likely to improve to an acceptable level after 10 minutes in leads with initial (33 of 47 vs 0 of 8, with vs without) and residual (29 of 33 vs 4 of 14, with vs without) current of injury recorded on the tip electrode (P < .0001). Lead perforation during the procedure has occurred in 11 patients who had no current of injury noted on the tip electrode. The ratio of current of injury recorded on the tip electrode to that on the ring electrode was correlated to the lead depth determined by sheath angiography (Spearman correlation coefficient -0.624; P < .0001), and microperforation is highly possible when the ratio is decreased to <1 (sensitivity 100%; specificity 96.6%). CONCLUSION: Current of injury is a useful tool in forecasting LBBP lead depth and septal perforation, and it could facilitate the decision-making process when the initial LBB capture threshold is undesirable.

The gut microbiome and microbial metabolites in acute myocardial infarction.

Emerging evidence has highlighted the role of gut microbiome in human health. However, the integrative role of gut microbiome and microbial metabolites in acute myocardial infarction (AMI) remains unclear. The current study profiles the microbial community through 16S rRNA gene sequencing and shotgun metagenomic sequencing and measures fecal short-chain fatty acids and circulating choline pathway metabolites among 117 new-onset AMI cases and 78 controls. Significant microbial alternations are observed in AMI patients compared with controls (P = 0.001). The abundances of nine species (e.g., Streptococcus salivarius and Klebsiella pneumoniae) are positively associated, and one species (Roseburia hominis) is inversely associated with AMI status and severity. A gut microbial score at disease onset is associated with the risk of major adverse cardiovascular events in 3.2 years (hazard ratio [95% CI]: 2.01 [1.04-4.24]) in AMI patients. The molar proportions of fecal acetate and butyrate are higher, and the circulating levels of choline and carnitine are lower in AMI patients than in controls. In addition, disease classifiers show that AMI cases and controls have a more distinct pattern in taxonomical composition than in pathways or metabolites. Our findings suggest that microbial composition and functional potentials are associated with AMI status and severity.

Sexual Dysfunction and the Impact of Beta-Blockers in Young Males With Coronary Artery Disease.

Objective: We aimed to assess the association of erectile dysfunction (ED) with the extent of coronary atherosclerosis, and to examine whether revascularization and medication use have an impact on ED status in patients with early onset of coronary artery disease (EOCAD). Methods: International Index of Erectile Function (IIEF-5) was used to evaluate sexual function in 296 male patients with EOCAD (age, 39.9 ± 4.8 years), and 354 male controls (age, 40.6 ± 4.4 years). The extent of coronary atherosclerosis was measured by Gensini score. Endothelial function was evaluated by two vasomotor indexes including endothelin-1 (ET-1) and nitric oxide (NO) by ELISA. Results: ED was more frequent (57.8 vs. 31.1%, P < 0.001) and serious (IIEF-5 score:17.7 ± 6.0 vs. 21.6 ± 5.0, P < 0.001) among EOCAD patients than that among controls. IIEF-5 score was negatively correlated with Gensini score (r = -0.383, P < 0.001). The adjusted odds ratio (OR) for the presence of ED (EOCAD vs. controls) was 1.88 [95% confidential interval (CI), 1.12-3.18]. However, ET-1 and NO attenuated the association between ED and EOCAD (adjusted OR: 1.54, 95% CI: 0.84-2.80). IIEF-5 score increased after coronary revascularization in patients not on beta-blockers (18.71 ± 4.84 vs. 17.59 ± 6.05, P < 0.001) as compared with baseline, while stayed unchanged in the subgroup using beta-blockers (17.82 ± 5.12 vs. 17.70 ± 5.98, P = 0.09). Conclusions: ED was common in patients with EOCAD, and associated with the severity of coronary atherosclerosis. Endothelial dysfunction may be a pathophysiologic mechanism underlying both ED and EOCAD. Coronary revascularization confers a benefit in ED amelioration, while this effect did not appear in patients using beta-blocker.

Circulating metabolites from the choline pathway and acute coronary syndromes in a Chinese case-control study.

BACKGROUND: Accumulating evidence shows that circulating levels of trimethylamine N-oxide, which is generated from the metabolism of dietary choline, may predict cardiovascular disease among Caucasians. Acute coronary syndrome (ACS), one common presentation of cardiovascular disease, is a spectrum of signs and symptoms due to acute decreased blood flow in the coronary arteries. The relationship between the metabolites from choline pathway and ACS remains unclear. We aimed to assess the associations of circulating metabolites from the choline pathway with ACS among a Chinese population, who consume a different dietary pattern than their Western counterparts. METHODS: We recruited 501 participants who were admitted to the Department of Cardiology, Zhongshan Hospital,Shanghai China between March 2017 and June 2018, including 254 ACS cases and 247 controls. Liquid chromatography-tandem mass spectrometry was used to measure circulating concentrations of metabolites in the choline pathway, including betaine, choline, trimethylamine, and trimethylamine N-oxide. A composite metabolite score using a weighted sum of these four metabolites, and the betaine/choline ratio were calculated. Multivariable logistic regressions were applied to estimate the association of metabolites with ACS, with adjustment of age, sex, body mass index, smoking index, history of diseases, and kidney function. RESULTS: After adjusting for traditional risk factors, per 1-standard deviation (SD) increment in choline was positively associated with the odds of ACS [odds ratio (OR), 95% confidence interval (CI), 1.77(1.44-2.18)], and the other metabolites were not associated with ACS at a statistical significance level. Compared with participants in the lowest quartile of the metabolite score, those in the highest quartile had higher odds of ACS [OR (95% CI), 3.18(1.85-5.54), p < 0.001 for trend]. Per 1-SD increment in metabolite score was positively associated with higher odds of ACS [OR (95% CI), 1.80 (1.37-2.40)], and per 1-SD increment in the betaine/choline ratio was inversely associated with the odds of ACS [OR (95% CI), 0.49 (0.39-0.60)]. CONCLUSIONS: Among our Chinese participants, trimethylamine N-oxide was not associated with ACS, while a composite metabolite score of metabolites from the choline pathway was associated with increased odds of ACS. The choline pathway metabolites may be related to the pathophysiology of ACS among Chinese.

M2 macrophage-derived exosomes carry microRNA-148a to alleviate myocardial ischemia/reperfusion injury via inhibiting TXNIP and the TLR4/NF-κB/NLRP3 inflammasome signaling pathway.

BACKGROUND: Reperfusion may cause injuries to the myocardium in ischemia situation. Emerging studies suggest that exosomes may serve as key mediators in myocardial ischemia/reperfusion (MI/R) injury. OBJECTIVE: The study was conducted to figure out the mechanism of M2 macrophage-derived exosomes (M2-exos) in MI/R injury with the involvement of microRNA-148a (miR-148a). METHODS AND RESULTS: M2 macrophages were prepared and M2-exos were collected and identified. Neonatal rat cardiomyocytes (NCMs) were extracted for in vitro hypoxia/reoxygenation (H/R) model establishment, while rat cardiac tissues were separated for in vivo MI/R model establishment. Differentially expressed miRNAs in NCMs and H/R-treated NCMs after M2-exos treatment were evaluated using microarray analysis. The target relation between miR-148a and thioredoxin-interacting protein (TXNIP) was identified using dual luciferase reporter gene assay. Gain- and loss- of function studies of miR-148a and TXNIP were performed to figure out their roles in MI/R injury. Meanwhile, the activation of the TLR4/NF-κB/NLRP3 inflammasome signaling pathway and pyroptosis of NCMs were evaluated. M2 macrophages carried miR-148a into NCMs. Over-expression of miR-148a enhanced viability of H/R-treated NCMs, reduced infarct size in vivo, and alleviated dysregulation of cardiac enzymes and Ca2+ overload in both models. miR-148a directly bound to the 3'-untranslated region (3'UTR) of TXNIP. Over-expressed TXNIP triggered the TLR4/NF-κB/NLRP3 signaling pathway activation and induced cell pyroptosis of NCMs, and the results were reproduced in in vivo studies. CONCLUSION: This study demonstrated that M2-exos could carry miR-148a to mitigate MI/R injury via down-regulating TXNIP and inactivating the TLR4/NF-κB/NLRP3 inflammasome signaling pathway. This study may offer new insights into MI/R injury treatment.

Ecto-5'-nucleotidase (CD73) is a potential target of hepatocellular carcinoma.

High expression of ecto-5'-nucleotidase (CD73) has been reported in a number of epithelium origin malignancies. Here, we hypothesize that CD73 promotes hepatocellular carcinoma (HCC) growth and metastasis and that the effect is mediated by epithelial growth factor receptor (EGFR). HCC cells with different malignancies and Tissue microarrays of the tumor and peritumoral liver tissues from 30 independent patients were used to examine CD73 and EGFR expression. Then, MTT and Ki67 detection, together with cell adhesion, invasion, and migration assays were used to evaluate the effects of CD73 on cell growth and metastasis. The expression of EGFR in HCC cells was also tested after suppressing or overexpressing CD73. Lastly, tumor tissues from nude mice, which had been injected subcutaneously with HCC cells, were transplanted subcutaneously into CD73-/- and wild-type (WT) C57 mice. CD73 expression was higher in HCC cells with greater metastatic potentials and tumor tissues compared with low metastatic cells and peritumor tissues. CD73 and EGFR were coexpressed and positively correlated in tumor and peritumor liver tissues in HCC tissue microarrays. Up-regulationof CD73 by plasmid transfection or by pharmacological agents promoted EGFR expression in HCC cells, whereas suppression of CD73 inhibited these effects. The growth of transplanted tumor tissues was dramatically slower in CD73-/- mice than in WT type mice in the in vivo experiments. CD73 promotes HCC growth and metastasis and upregulated the expression of EGFR in HCC. Thus, CD73 and EGFR are potential targets in the treatment of HCC.

Could persistency of current of injury forecast successful active-fixation pacing lead implantation?

BACKGROUND: Presence of adequate current of injury (COI) was recognized as a sign of favorable pacemaker lead outcome. Little is known regarding the value of its dynamic behavior. We sought to test whether persistency of COI could predict active-fixation pacing lead performance. METHODS: COI was monitored up to 10min after right ventricular (RV) pacing electrode fixation. COI persistency was defined as the percentage of COI magnitude relative to its initial measurement. An unacceptable pacing threshold (≥1.0V in acute evaluation or ≥2.0V over 2-year follow-up) with or without lead dislodgement was considered as lead failure. RESULTS: Lead implantation was attempted for 217 times in 174 patients (age 66.3±7.8years, 78 female). Acute lead failures occurred 43 times. Independent predictors of acute lead failure were RV enlargement (odds ratio [OR] 1.23, 95% confidential interval [CI] 1.11-2.04, P=0.033), absence of COI (OR 3.13, 95%CI 2.08-9.09, P=0.027), and COI persistency at 5min (OR 0.32, 95%CI 0.20-0.69, P=0.001) and 10min (OR 0.41, 95%CI 0.13-0.77, P=0.001). The optimal cutoffs were COI5min persistency ≥50% (sensitivity 81.4%; specificity 81.9%) and COI10min persistency ≥20% (sensitivity 86%; specificity 88.6%). There were 12 lead failures during 24.0±6.4months of follow-up. Patients with COI5min persistency ≥50% had higher event-free survival compared to those with COI5min persistency <50% (hazard ratio 3.54, 95% CI 1.04-12.06, P=0.043). CONCLUSIONS: COI persistency appears to be a valuable indicator for both acute and long-term outcome of active-fixation pacemaker leads. A precipitous decline in COI may require more attention to make sure of the lead performance.

Interatrial septal pacing to suppress atrial fibrillation in patients with dual chamber pacemakers: A meta-analysis of randomized, controlled trials.

BACKGROUND: Atrial fibrillation (AF) is of frequent occurrence in a population with bradycardia indicated for permanent dual chamber pacing. Whether selective site pacing at interatrial septum (IAS) could better prevent AF as compared with standard atrial pacing (AP) from right atrial appendage or high right atrium in these conditions remains in question. Its safety profile has yet to be elucidated. METHODS: Major web databases were searched up to February 2015 for controlled, randomized clinical trials on IAS versus conventional pacing. The primary end point was freedom from persistent/permanent AF. Secondary outcomes included device-recorded AF burden and frequency of AF episodes, lead-related complications, and major adverse events (MAEs). RESULTS: We identified 10 eligible studies incorporating a total of 1245 patients. Compared to conventional AP, IAS pacing conferred no additional benefit on the persistent/permanent AF free survival (hazard ratio 0.76, 95% confidence interval [CI] 0.48 to 1.22); it was associated with notably reduced device-detected AF burden (standard mean difference [SMD] -0.32, 95% CI -0.55 to -0.09) and AF frequency (SMD -0.54, 95% CI -0.83 to -0.24). The odds of lead-related complications (odds ratio [OR] 1.64, 95% CI 0.87 to 3.08) and combined rate of MAEs (OR 1.05, 95% CI 0.60 to 1.82) were similar between two groups. CONCLUSIONS: IAS pacing has no influence on the persistent/permanent AF progression and MAEs, although it appears to lower device-detected AF burden and AF frequency, and may carry similar risks of lead-related complications as compared to standard AP.

Time course of current of injury is related to acute stability of active-fixation pacing leads in rabbits.

BACKGROUND: Magnitude of current of injury (COI) consequent to pacemaker lead fixation is recognized as a predictor of acute lead stability. It is unclear whether dynamic monitoring of COI after lead fixation provides additional information beyond a single assessment performed at the time of fixation. OBJECTIVES: This study was aimed to test the hypothesis that the time course of COI is related to acute lead stability. METHODS AND RESULTS: Active fixation leads with fixed screw were anchored to either Langendorff-perfused rabbit hearts endocardially or in vivo hearts epicardially in manners of contact the helix with no rotation, half rotation and full rotation, respectively. Intracardiac electrogram (EGM) was monitored dynamically from onset to resolution of COI, and magnitudes of intrinsic R wave and COI, including ST-segment elevation, ST/R and intracardiac EGM duration (IED), were measured. A digital force gauge was applied to assess lead stability. In vitro, COI in contacted leads was significantly smaller than those in half rotated (p<0.05) and fully rotated leads (p<0.05), and presented most precipitous recovery to baseline (1.5±1.1 min, p<0.05). Half-rotated and fully rotated leads manifested the same magnitude of COI right after placement. However, the time course of COI was significantly longer in fully rotated leads than that in half rotated leads (26.5±2.8 min vs. 5.6±2.0 min, p<0.05). Similar findings were observed in vivo. The time course of COI was significantly correlated with the force needed to detach the lead from myocardium (r = 0. 72, n = 48, p<0.001). CONCLUSIONS: Time course of COI is related to acute lead stability in rabbits. One might be misled by a single assessment of COI magnitude right after lead placement, whereas persistence of COI is likely to be a useful indicator of adequate lead stability.