Dapagliflozin reduces the vulnerability of rats with pulmonary arterial hypertension-induced right heart failure to ventricular arrhythmia by restoring calcium handling.

BACKGROUND: Malignant ventricular arrhythmia (VA) is a major contributor to sudden cardiac death (SCD) in patients with pulmonary arterial hypertension (PAH)-induced right heart failure (RHF). Recently, dapagliflozin (DAPA), a sodium/glucose cotransporter-2 inhibitor (SGLT2i), has been found to exhibit cardioprotective effects in patients with left ventricular systolic dysfunction. In this study, we examined the effects of DAPA on VA vulnerability in a rat model of PAH-induced RHF. METHODS: Rats randomly received monocrotaline (MCT, 60 mg/kg) or vehicle via a single intraperitoneal injection. A day later, MCT-injected rats were randomly treated with placebo, low-dose DAPA (1 mg/kg/day), or high-dose (3 mg/kg/day) DAPA orally for 35 days. Echocardiographic analysis, haemodynamic experiments, and histological assessments were subsequently performed to confirm the presence of PAH-induced RHF. Right ventricle (RV) expression of calcium (Ca2+) handling proteins were detected via Western blotting. RV expression of connexin 43 (Cx43) was determined via immunohistochemical staining. An optical mapping study was performed to assess the electrophysiological characteristics in isolated hearts. Cellular Ca2+ imaging from RV cardiomyocytes (RVCMs) was recorded using Fura-2 AM or Fluo-4 AM. RESULTS: High-dose DAPA treatment attenuated RV structural remodelling, improved RV function, alleviated Cx43 remodelling, increased the conduction velocity, restored the expression of key Ca2+ handling proteins, increased the threshold for Ca2+ and action potential duration (APD) alternans, decreased susceptibility to spatially discordant APD alternans and spontaneous Ca2+ events, promoted cellular Ca2+ handling, and reduced VA vulnerability in PAH-induced RHF rats. Low-dose DAPA treatment also showed antiarrhythmic effects in hearts with PAH-induced RHF, although with a lower level of efficacy. CONCLUSION: DAPA administration reduced VA vulnerability in rats with PAH-induced RHF by improving RVCM Ca2+ handling.

Characterization of the complete chloroplast genome of Lonicera tangutica (Caprifoliaceae), an ornamental and medicinal plant in China.

In the present study, the complete chloroplast genome of Lonicera tangutica is presented and characterized for the first time. The complete chloroplast genome was 156,121 bp in length, including 23,899 bp inverted repeat (IR) regions, an 89,466 bp large single-copy (LSC) region, and an 18,851 bp small single-copy (SSC) region. A total of 129 genes, including 37 tRNA genes, eight rRNA genes, and 84 protein-coding genes, were annotated, and the overall GC content of the chloroplast genome was 38.35%. Two introns in the ycf3 gene and a single intron in another gene were detected. Maximum-likelihood phylogenetic analysis indicated that L. tangutica has a very close evolutionary relationship with Lonicera praeflorens, Lonicera hispida, Lonicera fragrantissima, and Lonicera stephanocarpa. These results are valuable for studying the evolution and genetic diversity of L. tangutica.

Towards Holistic Governance of China's E-Waste Recycling: Evolution of Networked Policies.

Electronic products are being updated and replaced much faster and there is therefore an increasing growth in electronic waste (e-waste). In order to promote professional recycling of e-waste, the relevant government departments of China have published a series of policies. This paper aims to unearth the evolution tendency of the networked policies towards holistic governance of China's e-waste recycling. Content analysis, quantitative text analysis and network analysis are applied to analyze relevant policy documents from 2001 to 2016. This paper illustrates evolution of policy themes, evolution of intergovernmental relationships, and evolution of policy relations. This study reveals policy intentions, maps policy progress, and unearths governance philosophy, providing an overall understanding of the policy ways by which the Chinese government has deployed its guiding strategies on professional recycling of e-waste. This paper illustrates how to approach holistic governance from perspective of networked policies, contributing to answering the central question of holistic governance about how to achieve it.

Median nerve stimulation prevents atrial electrical remodelling and inflammation in a canine model with rapid atrial pacing.

Aims: Studies have shown that stellate ganglion nerve activity has association with atrial electrical remodelling and atrial fibrillation (AF) inducibility, while median nerve stimulation (MNS) decreases cardiac sympathetic drive. In this study, we tested the hypothesis that MNS suppresses atrial electrical remodelling and AF vulnerability. Methods and results: The atrial effective refractory period (AERP) and AF inducibility at baseline and after 3 h of rapid atrial pacing were determined in dogs undergoing MNS (n = 7), MNS+ application of methyllycaconitine (n = 7) or sham procedure (n = 6). Then, the levels of tumour necrosis factor-alpha (TNF-a), interleukin-6 (IL-6), and acetylcholine (Ach) in the plasma and atrial tissues were measured. The control dogs (n = 4) were assigned to measure atrial inflammation cytokines. Short-term rapid atrial pacing induced shortening of the AERP, an increase in AERP dispersion, and an increase AF vulnerability in the sham dogs, which were all suppressed by MNS. Levels of TNF-a and IL-6 were higher, and Ach levels were lower in the left and the right atrium in the sham dogs than in the MNS dogs. Methyllycaconitine blunted the effects of MNS on the AERP, AERP dispersion, the AF vulnerability, and TNF-a and IL-6 levels in the atrium, but had no impact on the levels of Ach. Conclusions: The effects of MNS on atrial electrical remodelling and AF inducibility might be associated with the cholinergic anti-inflammatory pathway.

Naringenin inhibits transforming growth factor-ß1-induced cardiac fibroblast proliferation and collagen synthesis via G0/G1 arrest.

The Traditional Chinese Medicine naringenin (NRG) has a number of biological effects, including anti-inflammatory, anti-oxidative, anti-tumor and anti-atherosclerotic effects. However, the mechanism underlying its effects remains unclear. The aim of the present study is to investigate the role and mechanism of NRG on proliferation and collagen synthesis of cardiac fibroblasts (CFs) induced by transforming growth factor ß1 (TGF-ß1). Firstly, proliferation and collagen synthesis in CFs subjected to TGF-ß1 was assessed subsequent to the consumption of NRG or control treatment. Additionally, the cell cycle of different groups and the roles of cyclins and cyclin-dependent kinases (CDKs) in NRG treatment of CFs were detected. In the present study, it was revealed that treatment of CFs with NRG resulted in attenuated fibroblast α-smooth muscle actin expression, deceased proliferation and collagen synthesis when compared with a TGF-ß1 stimulus. Additionally, it was demonstrated that cell population of CFs treated with NRG in the S-phase became smaller whereas that of CFs in the G0/G1-phase increased when compared with the TGF-ß1 group. Mechanistically, the expression of cyclin D1-CDK4/6 and cyclin E2-CDK2 were inhibited in the NRG treatment group. These results illustrated that the protective effects of NRG on proliferation and collagen synthesis of CFs were at least in part due to G0/G1 arrest. Therefore, NRG may become a novel strategy for treating cardiac fibrosis in the future.

Effects of Traditional Chinese Medicine Shensong Yangxin Capsules on Heart Rhythm and Function in Congestive Heart Failure Patients with Frequent Ventricular Premature Complexes: A Randomized, Double-blind, Multicenter Clinical Trial.

BACKGROUND: Pharmacological therapy for congestive heart failure (CHF) with ventricular arrhythmia is limited. In the study, our aim was to evaluate the effects of Chinese traditional medicine Shensong Yangxin capsules (SSYX) on heart rhythm and function in CHF patients with frequent ventricular premature complexes (VPCs). METHODS: This double-blind, placebo-controlled, multicenter study randomized 465 CHF patients with frequent VPCs to the SSYX (n = 232) and placebo groups (n = 233) for 12 weeks of treatment. The primary endpoint was the VPCs monitored by a 24-h ambulatory electrocardiogram. The secondary endpoints included the left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter, N-terminal pro-brain natriuretic peptide (NT-proBNP), New York Heart Association (NYHA) classification, 6-min walking distance (6MWD), Minnesota Living with Heart Failure Questionnaire (MLHFQ) scores, and composite cardiac events (CCEs). RESULTS: The clinical characteristics were similar at baseline. SSYX caused a significantly greater decline in the total number of VPCs than the placebo did (-2145 ± 2848 vs. -841 ± 3411, P < 0.05). The secondary endpoints of the LVEF, NYHA classification, NT-proBNP, 6MWD, and MLHFQ scores showed a greater improvements in the SSYX group than in the placebo group (ΔLVEF at 12th week: 4.75 ± 7.13 vs. 3.30 ± 6.53; NYHA improvement rate at the 8th and 12th week: 32.6% vs. 21.8%, 40.5% vs. 25.7%; mean level of NT-proBNP in patients with NT-proBNP ≥125 pg/ml at 12th week: -122 [Q1, Q3: -524, 0] vs. -75 [Q1, Q3: -245, 0]; Δ6MWD at 12th week: 35.1 ± 38.6 vs. 17.2 ± 45.6; ΔMLHFQ at the 4th, 8th, and 12th week: -4.24 ± 6.15 vs. -2.31 ± 6.96, -8.19 ± 8.41 vs. -3.25 ± 9.40, -10.60 ± 9.41 vs. -4.83 ± 11.23, all P < 0.05). CCEs were not different between the groups during the study period. CONCLUSIONS: In this 12-week pilot study, SSYX was demonstrated to have the benefits of VPCs suppression and cardiac function improvement with good compliance on a background of standard treatment for CHF. TRIAL REGISTRATION: www.chictr.org.cn, ChiCTR-TRC-12002061 (http://www.chictr.org.cn/showproj.aspx?proj=7487) and Clinicaltrials.gov, NCT01612260 (https://clinicaltrials.gov/ct2/show/NCT01612260).

Effect of Shensong Yangxin on the Progression of Paroxysmal Atrial Fibrillation is Correlated with Regulation of Autonomic Nerve Activity.

BACKGROUND: Shensong Yangxin (SSYX), a traditional Chinese herbal medicine, has long been used clinically to treat arrhythmias in China. However, the mechanism of SSYX on atrial fibrillation (AF) is unknown. In this study, we tested the hypothesis that the effect of SSYX on the progression of paroxysmal AF is correlated with the regulation of autonomic nerve activity. METHODS: Eighteen mongrel dogs were randomly divided into control group (n = 6), pacing group (n = 6), and pacing + SSYX group (n = 6). The control group was implanted with pacemakers without pacing; the pacing group was implanted with pacemakers with long-term intermittent atrial pacing; the pacing + SSYX group underwent long-term intermittent atrial pacing and SSYX oral administration. RESULTS: Compared to the pacing group, the parameters of heart rate variability were lower after 8 weeks in the pacing + SSYX group (low-frequency [LF] component: 20.85 ± 3.14 vs. 15.3 ± 1.89 ms 2 , P = 0.004; LF component/high-frequency component: 1.34 ± 0.33 vs. 0.77 ± 0.15, P < 0.001). The atrial effective refractory period (AERP) was shorter and the dispersion of the AERP was higher after 8 weeks in the pacing group, while the changes were suppressed by SSYX intake. The dogs in the pacing group had more episodes and longer durations of AF than that in the pacing + SSYX group. SSYX markedly inhibited the increase in sympathetic nerves and upregulation of tumor necrosis factor-alpha and interleukin-6 expression in the pacing + SSYX group. Furthermore, SSYX suppressed the decrease of acetylcholine and α7 nicotinic acetylcholine receptor protein induced by long-term intermittent atrial pacing. CONCLUSIONS: SSYX substantially prevents atrial electrical remodeling and the progression of AF. These effects of SSYX may have association with regulating the imbalance of autonomic nerve activity and the cholinergic anti-inflammatory pathway.

Effect of coenzyme Q10 on the incidence of atrial fibrillation in patients with heart failure.

BACKGROUND: There is mounting evidence to support the influence of inflammation and oxidative stress in the pathogenesis of atrial fibrillation (AF) and heart failure (HF). The efficacy of coenzymeQ10 (CoQ10), an antioxidant used as an adjunct treatment in patients with AF and HF, remains less well established. METHODS: Consecutive patients with HF were randomized and divided into 2 groups: the CoQ10 group (combined administration of common drugs and CoQ10) and the control group (administration of common drugs). Ambulatory electrocardiogram Holter monitoring (24 hours), Doppler echocardiography, and evaluation of inflammatory cytokines were performed before treatment and 6 and 12 months after treatment. RESULTS: One hundred two patients (72 male and 30 female patients), with ages ranging from 45 to 82 years (mean age, 62.3 years), were examined. There was significant reduction in the level of malondialdehyde (3.9 ± 0.7 vs 2.5 ± 0.6 ng/mL; 3.9 ± 0.7 vs 2.3 ± 0.5 ng/mL, P < 0.05) in the CoQ10 group, whereas there was no significant difference (3.3 ± 0.8 vs 2.9 ± 0.8 ng/mL; 3.3 ± 0.8 vs 2.9 ± 0.5 ng/mL) in the control group after 6 and 12 months. Three patients (6.3%) in the CoQ10 group and 12 patients (22.2%) in the control group had episodes of AF after 12 months' treatment (P = 0.02). Four patients with AF in the control group went through the third Holter recording. CONCLUSIONS: CoenzymeQ10 as adjuvant treatment in patients with HF may attenuate the incidence of AF. The mechanisms of the effect perhaps have relation with the reduced levels of malondialdehyde.

Berberine attenuates spontaneous action potentials in sinoatrial node cells and the currents of human HCN4 channels expressed in Xenopus laevis oocytes.

The present study investigated the electropharmacological effects of a traditional Chinese herbal drug, berberine, on the spontaneous activity of sinoatrial nodes (SANs) of the rabbit heart and on human hyperpolarization-activated cyclic nucleotide-gated 4 (hHCN4) channels, which are heterologously expressed in xenopus oocytes, and which contribute to pacemaker currents (Ifs). A standard microelectrode technique and standard two­electrode voltage­clamp recordings were employed to examine the properties of transmembrane potentials and cloned hHCN4 subunit currents, respectively, under control conditions and berberine administration. Berberine decreased the rate of pacemaker firing and the rate of diastolic depolarization, and modified the action potential parameters. In addition, berberine suppressed the hHCN4 channel currents in a concentration­ (1­300 µM) and use­dependent manner, and simultaneously decreased the activation and deactivation kinetics of the hHCN4 channels. The ability of berberine to modulate the If of cardiac pacemaker cells may contribute to its antiarrhythmic action.

Assessment of ventricular electrophysiological characteristics at periinfarct zone of postmyocardial infarction in rabbits following stellate ganglion block.

UNLABELLED: Assessment of Ventricular Electrophysiological Characteristics. INTRODUCTION: The aim of this study was to investigate the characteristics of ventricular electrophysiology following stellate ganglion block (SGB) at periinfarct zone in rabbits with myocardial infarction (MI). METHODS AND RESULTS: Sixty-four rabbits were randomly assigned to 2 groups: MI (n = 32), ligation of the anterior descending coronary and sham operation (SO) (n = 32), without coronary ligation. Both MI and SO groups were divided into 4 subgroups according to right or left SGB and corresponding control (n = 8, each). After 8 weeks, 90% of monophasic action potential duration (MAPD90) of epicardium, midmyocardium and endocardium, transmural dispersion of repolarization (TDR), effective refractory period (ERP), and ventricular fibrillation threshold (VFT) were measured at the infarct border zone (MI group) and corresponding zone (SO group) following SGB. For SGB, 0.5 mL of 0.25% bupivacaine was used. Compared with the corresponding control group, in both the MI and SO groups, left SGB (LSGB) prolonged the MAPD90 of the 3 layers, reduced TDR, and increased ERP and VFT (P < 0.05). However, right SGB (RSGB) shortened MAPD90, increased TDR, and reduced ERP and VFT (P < 0.05). CONCLUSION: The results of this study demonstrate that LSGB can increase the electrophysiological stability of ventricular myocardium.

Effects of withdrawal of Xuezhikang, an extract of cholestin, on lipid profile and C-reactive protein: a short-term time course study in patients with coronary artery disease.

OBJECTIVE: C-reactive protein (CRP) is considered a risk factor for coronary artery disease. In addition to its lipid-lowering properties, statin decreases the level of CRP. Abrupt cessation of statin therapy during treatment could increase CRP level independently of the elevation of serum lipids and the incidence of cardiac events in patients with atherosclerotic heart disease. Xuezhikang (XZK), an extract of cholestin, has a marked modulating effect on lipid and CRP concentrations in different study time course. However, no attention has been paid to the changes of lipid profile and CRP concentrations after withdrawal of XZK treatment. This study was designed to explore short-term time course effects on lipid profile and CRP concentrations after withdrawal of XZK treatment in coronary heart disease patients. MATERIALS AND METHODS: Seventy-five consecutive patients with documented coronary heart disease were randomly divided into three groups: 1. Pretreatment with XZK 1,200 mg daily for 6 weeks and then replaced by placebo (XZK discontinued group; n = 25); 2. Treatment with XZK 1,200 mg daily throughout the study (XZK continued group; n = 25); or 3. Placebo (no XZK group; n = 25). Lipid levels (total cholesterol, HDL-C, LDL-C and triglycerides) and CRP were assessed before receiving the XZK therapy, 1 day before discontinuation of XZK, and on days 1, 2, 3, 7 and 14 after discontinuation of XZK, respectively. RESULTS: After 6-week XZK treatment, the fasting total cholesterol, LDL-C, triglyceride and median hs-CRP concentrations decreased, whereas HDL-C concentration increased significantly (p < 0.001, respectively). At day 14 after discontinuation of XZK therapy, total cholesterol (15%), LDL-C (17%) and triglyceride (20%) significantly increased (p < 0.001, respectively), whereas HDL-C level (15%) significantly decreased (p < 0.05). The median level of CRP increased by 11, 65, 128, 103 and 101% on the first, second, third, seventh, and fourteenth day after withdrawal of XZK therapy (p > 0.05, <0.05, <0.001, <0.001, <0.001, compared with 1 day before withdrawal of XZK therapy, respectively). There was a prominent rebound of CRP concentration 3 days after discontinuation of XZK therapy. At this time point, hs-CRP concentration was higher than in the placebo group (p < 0.05). Seven to 14 days after discontinuation of XZK therapy, the hs-CRP concentration declined to a similar level as in the placebo group. No significant correlation was seen between the changes in hs-CRP and lipid profile at all time points. CONCLUSIONS: The level of hs-CRP increases on the second day after withdrawal of XZK and there is a prominent rebound 3 days after discontinuation of XZK therapy. The increase of CRP ends within 7 days, where lipids increase at 14 days after discontinuation of XZK therapy. The results may be clinically important for patients with coronary artery disease.