Cardiac-specific deletion of BRG1 ameliorates ventricular arrhythmia in mice with myocardial infarction.

Malignant ventricular arrhythmia (VA) after myocardial infarction (MI) is mainly caused by myocardial electrophysiological remodeling. Brahma-related gene 1 (BRG1) is an ATPase catalytic subunit that belongs to a family of chromatin remodeling complexes called Switch/Sucrose Non-Fermentable Chromatin (SWI/SNF). BRG1 has been reported as a molecular chaperone, interacting with various transcription factors or proteins to regulate transcription in cardiac diseases. In this study, we investigated the potential role of BRG1 in ion channel remodeling and VA after ischemic infarction. Myocardial infarction (MI) mice were established by ligating the left anterior descending (LAD) coronary artery, and electrocardiogram (ECG) was monitored. Epicardial conduction of MI mouse heart was characterized in Langendorff-perfused hearts using epicardial optical voltage mapping. Patch-clamping analysis was conducted in single ventricular cardiomyocytes isolated from the mice. We showed that BRG1 expression in the border zone was progressively increased in the first week following MI. Cardiac-specific deletion of BRG1 by tail vein injection of AAV9-BRG1-shRNA significantly ameliorated susceptibility to electrical-induced VA and shortened QTc intervals in MI mice. BRG1 knockdown significantly enhanced conduction velocity (CV) and reversed the prolonged action potential duration in MI mouse heart. Moreover, BRG1 knockdown improved the decreased densities of Na+ current (INa) and transient outward potassium current (Ito), as well as the expression of Nav1.5 and Kv4.3 in the border zone of MI mouse hearts and in hypoxia-treated neonatal mouse ventricular cardiomyocytes. We revealed that MI increased the binding among BRG1, T-cell factor 4 (TCF4) and ß-catenin, forming a transcription complex, which suppressed the transcription activity of SCN5A and KCND3, thereby influencing the incidence of VA post-MI.

PFI-3 induces vasorelaxation with potency to reduce extracellular calcium influx in rat mesenteric artery.

Background: PFI-3 is a small-molecule inhibitor that targets the bromodomains (BRDs) of Brahma-related gene 1 (BRG1). This monomeric compound, which has high selectivity and potent cellular effects, has recently been developed. Although PFI-3 has been reported as a potential therapeutic agent targeting thrombomodulin, its role in the regulation of vascular function remains unknown. Therefore, we aimed to investigate the impact of PFI-3 on arterial vessel tone. Methods: A microvascular tension measurement device (DMT) was utilized to identify alterations in vascular tension within the mesenteric artery. To detect variations in cytosolic [Ca2+]i, a Fluo-3/AM fluorescent probe and fluorescence microscope were employed. Additionally, whole-cell patch clamp techniques were utilized to evaluate the activity of L-type voltage-dependent calcium channels (VDCCs) in cultured arterial smooth muscle cells (A10 cells). Results: PFI-3 exerted a dose-dependent relaxation effect on rat mesenteric arteries with both intact and denuded endothelium after phenylephrine (PE)- and high-K+-induced constriction. PFI-3-induced vasorelaxation was not affected by the presence of L-NAME/ODQ or K+ channel blockers (Gli/TEA). PFI-3 abolished Ca2+-induced contraction on endothelium-denuded mesenteric arteries preincubated by PE in Ca2+-free solution. Incubation with TG had no impact on PFI-3-induced vasorelaxation pre-contracted by PE. PFI-3 reduced Ca2+-induced contraction on endothelium-denuded mesenteric arteries pre-incubated by KCl (60 mM) in Ca2+-free solution. PFI-3 declined extracellular calcium influx in A10 cells detected by Fluo-3/AM fluorescent probe and fluorescence microscope. Furthermore, we observed that PFI-3 decreased the current densities of L-type VDCC by whole-cell patch clamp techniques. Conclusions: PFI-3 blunted PE and high K+-induced vasoconstriction independent of endothelium on rat mesenteric artery. The vasodilatory effect of PFI-3 may be attributed to its inhibition of VDCCs and receptor-operated calcium channels (ROCCs) on vascular smooth muscle cells (VSMCs).

Repression of liver cirrhosis achieved by inhibitory effect of miR-454 on hepatic stellate cells activation and proliferation via Wnt10a.

As is known, hepatic stellate cells (HSCs) activation contributes to liver cirrhosis. This study aims to find out the acting mechanisms of miR-454 inhibiting the activation and proliferation of hepatic stellate cells. The expression of Col1A1, α-smooth muscle actin (α-SMA) and Wnt10a were determined by western blot, and the miR-454 level was determined by quantitative real-time PCR in this study. We took two objects as experiment subjects, one was liver cirrhosis rats, and the other was transforming growth factor (TGF)-ß1-stimulated HSC-T6 cells. After activated with TGF-ß1 and transfected with microRNA-454 mimic, separately or successively, the changes on the Col1A1 and α-SMA expression, HSC proliferation, miR-454 level and Wnt10a expression were examined in HSC-T6 cells, respectively. Interaction between miR-454 and Wnt10a was evaluated with dual luciferase reporter assay. MiR-454 expression was down-regulated in tissues of liver cirrhosis rats. TGF-ß1 caused the down-regulation of the miR-454 in HSC-T6 cells. MiR-454 inhibited the activation and proliferation of HSC-T6 cells. Wnt10a had a targeting relationship with miR-454. TGF-ß1 promoted HSC-T6 activation and proliferation via down-regulating miR-454 expression, which further up-regulated Wnt10a expression. MiR-454 mimic inhibited cirrhosis progression in liver cirrhosis rats. MiR-454 can inhibit the activation and proliferation of HSCs via suppressing the expression of Wnt10a, to restrain liver cirrhosis.

The pretransplant neutrophil-lymphocyte ratio as a new prognostic predictor after liver transplantation for hepatocellular cancer: a systematic review and meta-analysis.

AIM: Recently, many reports showed that the pretransplant neutrophil-lymphocyte ratio (NLR) may be correlated with the prognosis of patients undergoing liver transplantation (LT) for hepatocellular cancer (HCC). However, their results still remained controversial. Thus we performed a meta-analysis of 13 studies to estimate the prognostic value of pretransplant NLR. METHODS: Databases including PubMed, Embase, Cochrane Library and Web of Science were searched to September 2017. Hazard ratio (HR) or odds ratio (OR) with its 95% CI was used to evaluate the association between elevated NLR and the prognosis or clinical features of liver cancer patients. RESULTS: A total of 13 studies including 1936 patients were included in this meta-analysis. Elevated pretransplant NLR had a close association with the overall survival (HR: 2.22; 95% CI: 1.34-3.68), recurrence-free survival (HR: 3.77; 95% CI: 2.01-7.06) and disease-free survival (HR: 2.51; 95% CI: 1.22-5.15) of patients undergoing LT for HCC, respectively. In addition, elevated NLR was associated with the presence of vascular invasion (OR: 2.39; 95% CI: 1.20-4.77) and Milan criteria (OR: 0.26; 95% CI: 0.17-0.40). CONCLUSION: The results of this meta-analysis showed that elevated pretransplant NLR may be used as a new prognostic predictor after LT for HCC.

[Genetic identification of internal transcribed spacers sequence in rDNA of Artemisis iwayomogi Kitam. and other two Artemisia species].

OBJECTIVE: To make an useful identification method for the molecule of DNA on 3 herbs of Artemisia genus and compare the differences of the genes of Korean and Chinese species of Artemisia. METHODS: Sequence of 3 herbs (Artemisia sacrorum Ledeb., Artemisia iwayomogi Kitam. and Artemisia capillaris Thunb.) was determined by PCR sequence system. DNA was extracted from rDNA/ITS (internal transcribed spacers) and 5.8 s. The analysis was based on the amplification through DNA sequence system. RESULTS: There were profound differences between the Korean Artemisia and Artemisia sacrorum L. These 2 herbs had a difference in the PCR amplifications of the agarose gel electrophoresis. There was a slight difference in the analysis of the DNA sequence system, and the substitution percentage for ITS gene fragments sequence was 3.96%. CONCLUSION: Analytic identification method on sequence system of ITS in rDNA is effective for these 3 herbs.