Echinacoside inhibited cardiomyocyte pyroptosis and improved heart function of HF rats induced by isoproterenol via suppressing NADPH/ROS/ER stress.

Prevalence of heart failure (HF) continues to rise over time and is a global difficult problem; new drug targets are urgently needed. In recent years, pyroptosis is confirmed to promote cardiac remodelling and HF. Echinacoside (ECH) is a natural phenylethanoid glycoside and is the major active component of traditional Chinese medicine Cistanches Herba, which is reported to possess powerful anti-oxidation and anti-inflammatory effects. In addition, we previously reported that ECH reversed cardiac remodelling and improved heart function, but the effect of ECH on pyroptosis has not been studied. So, we investigated the effects of ECH on cardiomyocyte pyroptosis and the underlying mechanisms. In vivo, we established HF rat models induced by isoproterenol (ISO) and pre-treated with ECH. Indexes of heart function, pyroptotic marker proteins, ROS levels, and the expressions of NOX2, NOX4 and ER stress were measured. In vitro, primary cardiomyocytes of neonatal rats were treated with ISO and ECH; ASC speckles and caspase-1 mediated pyroptosis in cardiomyocytes were detected. Hoechst/PI staining was also used to evaluate pyroptosis. ROS levels, pyroptotic marker proteins, NOX2, NOX4 and ER stress levels were all tested. In vivo, we found that ECH effectively inhibited pyroptosis, down-regulated NOX2 and NOX4, decreased ROS levels, suppressed ER stress and improved heart function. In vitro, ECH reduced cardiomyocyte pyroptosis and suppressed NADPH/ROS/ER stress. We concluded that ECH inhibited cardiomyocyte pyroptosis and improved heart function via suppressing NADPH/ROS/ER stress.

CaMKII inhibitor KN-93 impaired angiogenesis and aggravated cardiac remodelling and heart failure via inhibiting NOX2/mtROS/p-VEGFR2 and STAT3 pathways.

Persistent cardiac Ca2+ /calmodulin-dependent Kinase II (CaMKII) activation was considered to promote heart failure (HF) development, some studies believed that CaMKII was a target for therapy of HF. However, CaMKII was an important mediator for the ischaemia-induced coronary angiogenesis, and new evidence confirmed that angiogenesis inhibited cardiac remodelling and improved heart function, and some conditions which impaired angiogenesis aggravated ventricular remodelling. This study aimed to investigate the roles and the underlying mechanisms of CaMKII inhibitor in cardiac remodelling. First, we induced cardiac remodelling rat model by ISO, pre-treated by CaMKII inhibitor KN-93, evaluated heart function by echocardiography measurements, and performed HE staining, Masson staining, Tunel staining, Western blot and RT-PCR to test cardiac remodelling and myocardial microvessel density; we also observed ultrastructure of cardiac tissue with transmission electron microscope. Second, we cultured HUVECs, pre-treated by ISO and KN-93, detected cell proliferation, migration, tubule formation and apoptosis, and carried out Western blot to determine the expression of NOX2, NOX4, VEGF, VEGFR2, p-VEGFR2 and STAT3; mtROS level was also measured. In vivo, we found KN-93 severely reduced myocardial microvessel density, caused apoptosis of vascular endothelial cells, enhanced cardiac hypertrophy, myocardial apoptosis, collagen deposition, aggravated the deterioration of myocardial ultrastructure and heart function. In vitro, KN-93 inhibited HUVECs proliferation, migration and tubule formation, and promoted apoptosis of HUVECs. The expression of NOX2, NOX4, p-VEGFR2 and STAT3 were down-regulated by KN-93; mtROS level was severely reduced by KN-93. We concluded that KN-93 impaired angiogenesis and aggravated cardiac remodelling and heart failure via inhibiting NOX2/mtROS/p-VEGFR2 and STAT3 pathways.

Quercetin improves atrial fibrillation through inhibiting TGF-ß/Smads pathway via promoting MiR-135b expression.

PURPOSE: To investigate the role and mechanism of quercetin in isoprenaline (ISO)-induced atrial fibrillation (AF). STUDY DESIGN: Rat cardiac fibroblasts (RCFs) models and RCFs were used to explore the effect and underlying mechanism of quercetin in isoprenaline (ISO)-induced atrial fibrillation (AF) in vivo and in vitro by a series of experiments. METHODS: Differentially expressed microRNAs were screened from human AF tissues using the GEO2R and RT-qPCR. The expressions of TGF-ß/Smads pathway molecules (TGFß1, TGFBR1, Tgfbr1, Tgfbr2, Smad2, Smad3, Smad4) in AF tissues were detected by RT-qPCR and Western blot. The relationships between miR-135b and genes (Tgfbr1, Tgfbr2, Smad2) were analyzed by Pearson correlation, TargetScan and dual-luciferase activity assay. RCFs induced by ISO were treated with quercetin (20 or 50 µM), miR-135b mimic and inhibitor, siTgfbr1 and their corresponding controls, then the cell viability was determined by MTT and the expressions of cyclin D1, α-SMA, collagen-related molecules, TGF-ß/Smads pathway molecules, and miR-135b were measured by RT-qPCR and Western blot. ISO-induced rats were treated with quercetin (25 mg/kg/day) via gavage, miR-135b antagomir, agomir and their corresponding controls. The treated rats were used for the detection of miR-135b expression by RT-qPCR, histopathological observation by HE and Masson staining, and the detection of Col1A1 and fibronectin contents by immunohistochemical technique. RESULTS: The expression of miR-135b was downregulated, and those of TGFBR1, TGFBR2, target genes of miR-135b were upregulated in human AF tissues and negatively regulated by miR-135b in RCFs. Through inhibiting TGF-ß/Smads pathway via promoting miR-135b expression, quercetin treatment inhibited proliferation, myofibroblast differentiation and collagen deposition in ISO-treated RCFs, as evidenced by reduced expressions of cyclin D1, α-SMA, collagen-related genes and proteins, and alleviated fibrosis and collagen deposition of atrial tissues in ISO-treated rats. CONCLUSION: Quercetin may alleviate AF by inhibiting fibrosis of atrial tissues through inhibiting TGF-ß/Smads pathway via promoting miR-135b expression.

Echinacoside reverses myocardial remodeling and improves heart function via regulating SIRT1/FOXO3a/MnSOD axis in HF rats induced by isoproterenol.

Myocardial remodelling is important pathological basis of HF, mitochondrial oxidative stress is a promoter to myocardial hypertrophy, fibrosis and apoptosis. ECH is the major active component of a traditional Chinese medicine Cistanches Herba, plenty of studies indicate it possesses a strong antioxidant capacity in nerve cells and tumour, it inhibits mitochondrial oxidative stress, protects mitochondrial function, but the specific mechanism is unclear. SIRT1/FOXO3a/MnSOD is an important antioxidant axis, study finds that ECH binds covalently to SIRT1 as a ligand and up-regulates the expression of SIRT1 in brain cells. We hypothesizes that ECH may reverse myocardial remodelling and improve heart function of HF via regulating SIRT1/FOXO3a/MnSOD signalling axis and inhibit mitochondrial oxidative stress in cardiomyocytes. Here, we firstly induce cellular model of oxidative stress by ISO with AC-16 cells and pre-treat with ECH, the level of mitochondrial ROS, mtDNA oxidative injury, MMP, carbonylated protein, lipid peroxidation, intracellular ROS and apoptosis are detected, confirm the effect of ECH in mitochondrial oxidative stress and function in vitro. Then, we establish a HF rat model induced by ISO and pre-treat with ECH. Indexes of heart function, myocardial remodelling, mitochondrial oxidative stress and function, expression of SIRT1/FOXO3a/MnSOD signalling axis are measured, the data indicate that ECH improves heart function, inhibits myocardial hypertrophy, fibrosis and apoptosis, increases the expression of SIRT1/FOXO3a/MnSOD signalling axis, reduces the mitochondrial oxidative damages, protects mitochondrial function. We conclude that ECH reverses myocardial remodelling and improves cardiac function via up-regulating SIRT1/FOXO3a/MnSOD axis and inhibiting mitochondrial oxidative stress in HF rats.

Cooperative and Independent Effect of Modular Functionalization on Mesomorphic Performances and Microphase Separation of Well-Designed Liquid Crystalline Diblock Copolymers.

Liquid crystalline block copolymers (LCBCPs) are promising for developing functional materials owing to an assembly of better functionalities. Taking advantage of differences in reactivity between alkynyl and vinyl over temperature during hydrosilylation, a series of LCBCPs with modular functionalization of the block copolymers (BCPs) are reported by independently and site-selectively attaching azobenzene moieties containing alkynyl (LC1 ) and Si-H (LC2 ) terminals into well-designed poly(styrene)-block-polybutadienes (PS-b-PBs) and poly(4-vinylphenyldimethylsilane)-block-polybutadienes (PVPDMS-b-PBs) produced from living anionic polymerization (LAP). By the principle of modular functionalization, it is demonstrated that mono-functionalized (PVPDMS-g-LC1 )-b-PB and PS-b-(PB-g-LC2 ) not only maintain independence but also have cooperative contributions to bi-functionalized (PVPDMS-g-LC1 )-b-(PB-g-LC2 ) in terms of mesomorphic performances and microphase separation, which is evident from differential scanning calorimetry (DSC) and polarized optical morphologies (POM) and identified by powder X-ray diffractions. With the application of the new principle of modular functionalization, local-crosslinked liquid crystalline networks (LCNs) with controlled functionality are successfully synthesized, which show well-controlled phase behaviors over molecular compositions.

Bisoprolol reversed small conductance calcium-activated potassium channel (SK) remodeling in a volume-overload rat model.

A recent study indicated that apamin-sensitive current (I KAS, mediated by apamin-sensitive small conductance calcium-activated potassium channels subunits) density significantly increased in heart failure and led to recurrent spontaneous ventricular fibrillation. While the underlying molecular correlation with SK channels is still undetermined, we hypothesized that they are remodeled in HF and that bisoprolol could reverse the remodeling. Volume-overload models were created on male Sprague-Dawley rats by producing an abdominal arteriovenous fistula. Confocal microscopy, quantitative real-time PCR, and western blot were performed to investigate the expression of SK channels and observe the influence of ß-blocker bisoprolol on the expression of SK channels I KAS, and the effect of bisoprolol on I KAS and the sensitivity of I KAS to [Ca(2+)]i at single isolated cells were also explored using whole-cell patch clamp techniques. SK channels were remodeled in HF rats, displaying the significant increase of SK1 and SK3 channel expression. After the treatment of HF rats with bisoprolol, the expression of SK1 and SK3 channels was significantly downregulated, and bisoprolol effectively downregulated I KAS density as well as the sensitivity of I KAS to [Ca(2+)]i. Our data indicated that the expression of SK1 and SK3 increased in HF. Bisoprolol effectively attenuated the change and downregulated I KAS density as well as the sensitivity of I KAS to [Ca(2+)]i.

Effectiveness of Chinese herbal medicine as an adjunctive treatment for dilated cardiomyopathy in patients with heart failure.

OBJECTIVES: To evaluate the effectiveness and safety of Chinese herbal medicine (CHM) as an adjunctive treatment for patients with dilated cardiomyopathy (DCM) and heart failure. DESIGN: Studies on biomedical treatment plus CHM versus biomedical treatment alone in treating patients with DCM and heart failure were retrieved from PubMed and other major databases (1980-2011). Meta-analysis was performed on the overall effects on effective rate, left ventricular ejection fraction, left ventricular diastolic end diameter, and other outcome measures. RESULTS: Twenty-seven studies with 1887 patients were included. Compared with biomedical treatment alone, biomedical treatment plus CHM showed significant improvement in effective rate (relative risk, 1.26; 95% confidence interval [CI], 1.19-1.34), left ventricular ejection fraction (%) (mean difference, 5.88; 95% CI, 3.92-7.85), left ventricular diastolic end diameter (mm) (mean difference, -2.78; 95% CI, -5.15 to -0.42), and other outcome measures. Most adverse events observed in the studies were not severe and resolved without special treatment. CONCLUSIONS: This meta-analysis indicated that biomedical treatment plus CHM is more effective than biomedical treatment alone in treating patients with DCM and heart failure. However, further studies with long-term follow-up, systemic adverse events evaluation, and other ethnic groups are still required to verify the efficacy and safety of CHM as an adjunctive treatment in all patients with DCM and heart failure.

Mesenchymal stem cells neither fully acquire the electrophysiological properties of mature cardiomyocytes nor promote ventricular arrhythmias in infarcted rats.

Electrophysiological properties of implanted mesenchymal stem cells (MSCs) in infarcted hearts remain unclear, and their proarrhythmic effect is still controversial. The intent of this study was to investigate electrophysiological properties and proarrhythmic effects of MSCs in infarcted hearts. Rats were randomly divided into a myocardial infarction (MI) group, a MI-DMEM group (received DMEM medium injection) and MI-MSCs group (received MSCs injection). Survival analysis showed that the majority of engrafted MSCs died at day 9 after transplantation. Engrafted MSCs expressed cardiac markers (MYH, cTnI, Cx43), cardiac ion channel genes (Kv1.4, Kv4.2 and Kir2.1) and potassium currents (I (to), I (K1) and I (KDR)), but did not express Nav1.5, Cav1.2, Na(+) current and Ca(2+) current during their survival. When induced by Ca(2+), implanted MSCs exhibited no contraction ability after being isolated from the heart. Following 8-week electrocardiography monitoring, the cumulative occurrence of ventricular arrhythmias (VAs) was not different among the three groups. However, the prolonged QRS duration in infarcted rats without VAs was significantly decreased in the MI-MSCs group compared with the other two groups. The inducibility of VAs in the MI-MSCs group was much lower than that in the MI and MI-DMEM groups (41.20 vs. 86.67 % and 92.86 %; P < 0.0125). The ventricular effective refractory period in MI-MSCs group was prolonged in comparison with that in the MI and MI-DMEM groups (56.0 ± 8.8 vs. 47.7 ± 8.8 ms and 45.7 ± 6.2 ms; P < 0.01). These results demonstrate that MSCs do not acquire the electrophysiological properties of mature cardiomyocytes during the survival period in the infarcted hearts. However, they can alleviate the electrical vulnerability and do not promote ventricular arrhythmias.

Characteristics and interactions of Helicobacter pylori and H. pylori-infected human gastroduodenal epithelium in peptic ulcer: a transmission electron microscopy study.

Helicobacter pylori (H. pylori) has been presumed to be an initiating factor in a previously recognized chain of events, starting with active chronic gastritis and leading to atrophy of the mucosal membrane, intestinal metaplasia, dysplasia (intraepithelial neoplasia), and finally culminating in gastric carcinoma. Adherence of H. pylori to the gastroduodenal epithelium is believed to be an important step in the induction of active chronic inflammation of the mucosal layer. However, it is not clear how the pathogen chronically colonizes the gastroduodenal epithelium. In this study, 30 biopsy specimens from H. pylori-positive peptic ulcer (15 for gastric ulcer, 15 for duodenal ulcer) patients were examined by transmission electron microscopy (TEM) to observe the structural adherence of H. pylori to gastroduodenal epithelium while ten healthy postulants were served as controls. We also investigated the interaction between H. pylori and gastroduodenal epithelial cells. Morphological appearances of both the pathogen and the cells as well as features of colonization, attachment, and internalization were observed. H. pylori exhibited both spiral and coccoid forms. Cytoplasmic vacuolar degeneration played by the vacuolating toxin (VacA) was apparent in gastroduodenal epithelial cells. Specially, a number of tumor cells were found in H. pylori-positive gastric intestinal metaplasia (IM) mucosa under TEM which provided an ultrastructural evidence of IM carrying a particularly high risk for the development of gastric cancer.