Notch1-Mediated Histone Demethylation of HCN4 Contributes to Aconitine-induced Ventricular Myocardial Dysrhythmia.
Notch1-Mediated HCN4 的组蛋白去甲基化有助于乌头碱诱导的心室心肌节律障碍。
- 作者列表："Zhou W","Qiu LZ","Liu H","Deng HF","Yue LX","Gao Y
:Traditional Chinese Medicines (TCMs)-containing aconitine are popular and indispensable home remedies in Asia for thousands of years due to its excellent pharmaceutical effects. Accumulating evidence has identified that repeated-dose of aconitine could cause polymorphic ventricular arrhythmias. However, underlying molecular mechanisms are still not fully understood. Hence, the present study firstly investigated the potential role of Notch1 signaling in aconitine-induced cardiotoxicity, aiming to elaborate possible molecular mechanisms involved in aconitine triggered ventricular arrhythmias. Our results showed that aconitine increased Notch1 signaling and downstream KDM5A expression in human and rat cardiomyocytes at non-detectable cytotoxic doses. Furthermore, aconitine promoted the formation of a new regulatory complex containing NICD and KDM5A in a CK2αHI regime, which then targeted to HCN4 promoter and induced re-expression of HCN4 in mature cardiomyocytes. Ultimately, HCN4-mediated If current contributed to aconitine-caused alterations in beating rate of rat cardiomyocytes. All changes aforementioned were significantly ameliorated by Notch1 inhibitor, suggesting that Notch1-mediated epigenetic regulation of HCN4 contributes to aconitine-induced ventricular myocardial dysrhythmia. Thus, our findings provide a novel toxic mechanism and position Notch1/NICD/KDM5A/HCN4 toxicity pathway as a potential target for the treatments of repeated-dose of medicine containing aconitine induced ventricular arrhythmias.
: 含有乌头碱的中药 (TCMs) 由于其卓越的药物作用，是亚洲几千年来流行和不可或缺的家庭疗法。越来越多的证据表明，重复剂量的乌头碱可引起多形性室性心律失常。然而，潜在的分子机制仍不完全清楚。因此，本研究首先研究了 Notch1 信号在乌头碱诱导的心脏毒性中的潜在作用，旨在阐述乌头碱引发室性心律失常的可能分子机制。我们的结果表明，乌头碱在不可检测的细胞毒性剂量下增加了人和大鼠心肌细胞 Notch1 信号和下游 KDM5A 的表达。此外，乌头碱在 ck2 α hi 状态下促进了含有 NICD 和 KDM5A 的新调控复合物的形成，然后靶向 HCN4 启动子，诱导成熟心肌细胞中 HCN4 的再表达。最终，如果电流 HCN4-mediated 促成了乌头碱引起的大鼠心肌细胞搏动率的改变。Notch1 抑制剂显著改善上述所有变化，提示 Notch1-mediated HCN4 的表观遗传调控有助于乌头碱诱导的心室心肌节律障碍。因此，我们的发现提供了一种新的毒性机制，将 Notch1/NICD/KDM5A/HCN4 毒性通路定位为治疗重复剂量含乌头碱药物诱导的室性心律失常的潜在靶点。
METHODS:AIMS:Pulmonary vein isolation (PVI) using ablation index (AI) incorporates stability, contact force (CF), time, and power. The CLOSE protocol combines AI and ≤6 mm interlesion distance. Safety concerns are raised about surround flow ablation catheters (STSF). To compare safety and effectiveness of an atrial fibrillation (AF) ablation strategy using AI vs. CLOSE protocol using STSF.,METHODS AND RESULTS:First cluster was treated using AI and second cluster using CLOSE. Procedural data, safety, and recurrence of any atrial tachycardia (AT) or AF >30 s were collected prospectively. All Classes 1c and III anti-arrhythmic drugs (AAD) were stopped after the blanking period. In total, all 215 consecutive patients [AI: 121 (paroxysmal: n = 97), CLOSE: n = 94 (paroxysmal: n = 74)] were included. Pulmonary vein isolation was reached in all in similar procedure duration (CLOSE: 107 ± 25 vs. AI: 102 ± 24 min; P = 0.1) and similar radiofrequency time (CLOSE: 36 ± 11 vs. AI: 37 ± 8 min; P = 0.4) but first pass isolation was higher in CLOSE vs. AI [left veins: 90% vs. 80%; P < 0.05 and right veins: 84% vs. 73%; P < 0.05]. Twelve-month off-AAD freedom of AF/AT was higher in CLOSE vs. AI [79% (paroxysmal: 85%) vs. 64% (paroxysmal: 68%); P < 0.05]. Only four patients (2%) without recurrence were on AAD during follow-up. Major complications were similar (CLOSE: 2.1% vs. AI: 2.5%; P = 0.87).,CONCLUSION:The CLOSE protocol is more effective than a PVI approach solely using AI, especially in paroxysmal AF. In this off-AAD study, 79% of patients were free from AF/AT during 12-month follow-up. The STSF catheter appears to be safe using conventional CLOSE targets.
METHODS:OBJECTIVE:To investigate the role of driver mechanism and the effect of electrogram dispersion-guided driver mapping and ablation in atrial fibrillation (AF) at different stages of progression.,METHODS:A total of 256 consecutive patients with AF who had undergone pulmonary vein isolation (PVI) plus driver ablation or conventional ablation were divided into three groups: paroxysmal atrial fibrillation (PAF; group A, n = 51); persistent atrial fibrillation (PsAF; group B, n = 38); and long standing-persistent atrial fibrillation (LS-PsAF; group C, n = 39). PVI was performed with the guidance of the ablation index. The electrogram dispersion was analyzed for driver mapping.,RESULTS:The most prominent driver regions were at roof (28.0%), posterior wall (17.6%), and bottom (21.3%). From patients with PAF to those with PsAF and LS-PsAF: the complexity of extra-pulmonary vein (PV) drivers including distribution, mean number, and area of dispersion region increased (P < .001). Patients who underwent driver ablation vs conventional ablation had higher procedural AF termination rate (76.6% vs 28.1%; P < .001). With AF progression, the termination rate gradually decreased from group A to group C, and the role of PVI in AF termination was also gradually weakened from group A to group C (39.6%, 7.4%, and 4.3%; P < .001) in patients with driver ablation. At the end of the follow-up, the rate of sinus rhythm maintenance was higher in patients with driver ablation than those with conventional ablation (89.1% vs 70.3%; P < .001).,CONCLUSION:The formation of extra-PV drivers provides an important mechanism for AF maintenance with their complexity increasing with AF progression. Electrogram dispersion-guided driver ablation appears to be an efficient adjunctive approach to PVI for AF treatment.
METHODS:PURPOSE:Whether or not pulmonary vein isolation (PVI) plus left atrial posterior wall isolation (PWI) using contact force (CF) sensing improves the ablation outcome for persistent atrial fibrillation (AF) is unclear. This study compared the outcome of PVI plus PWI and additional non-PV trigger ablation for persistent AF with/without CF sensing. METHODS:This retrospective cohort study analyzed 148 propensity score-matched persistent AF patients (median duration of persistent AF, 8 months (interquartile range, 3-24 months); left atrial diameter, 43 ± 7 mm) undergoing PVI plus PWI and ablation of non-PV triggers provoked by high-dose isoproterenol, including 74 with CF-sensing catheters (CF group) and 74 with conventional catheters (non-CF group). PVI plus PWI with no additional ablation but cavotricuspid isthmus ablation was performed without non-PV triggers in 48 CF patients (65%) and 54 non-CF patients (73%) (P = 0.38). In all other patients, we performed additional ablation of provoked non-PV triggers. RESULTS:The Kaplan-Meier estimate of the rate of freedom from atrial tachyarrhythmia recurrence of antiarrhythmic drugs at 12 months after the single procedure was higher in the CF group than in the non-CF group (85 vs. 70%, log-rank P = 0.030). A multivariable analysis revealed that using CF sensing and non-inducibility of AF from a non-PV trigger after PVI and PWI were significantly associated with a reduced rate of atrial tachyarrhythmia recurrence. CONCLUSIONS:Compared with non-CF sensing, PVI plus PWI and additional non-PV trigger ablation using CF-sensing catheters for persistent AF can reduce the rate of atrial tachyarrhythmia recurrence.