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.

Effect of Food Restriction on Food Grinding in Brandt's Voles.

Food grinding is supposed to be influenced by multiple factors. However, how those factors affecting this behavior remain unclear. In this study, we investigated the effect of food restriction on food grinding in Brandt's voles (Lasiopodomys brandtii), as well as the potential role of the gut microbiota in this process, through a comparison of the variations between voles with different food supplies. Food restriction reduced the relative amount of ground food to a greater extent than it lowered the relative food consumption, and altered the abundance of Staphylococcus, Aerococcus, Jeotgalicoccus, and Un--s-Clostridiaceae bacterium GM1. Fecal acetate content for the 7.5 g-food supply group was lower than that for the 15 g-food supply group. Our study indicated that food restriction could effectively inhibit food grinding. Further, Un--s-Clostridiaceae bacterium GM1 abundance, Aerococcus abundance, and acetate content were strongly related to food grinding. Variations in gut microbial abundance and short-chain fatty acid content induced by food restriction likely promote the inhibition of food grinding. These results could potentially provide guidance for reducing food waste during laboratory rodent maintenance.

Efficient electroreduction of CO to acetate using a metal-azolate framework with dicopper active sites.

Electrochemical reduction of CO to value-added products, especially C2 products, provides a potential approach to achieve carbon neutrality and overcome the energy crisis. Herein, we report a metal-azolate framework (CuBpz) with dicopper active sites as an electrocatalyst for the electrochemical CO reduction reaction (eCORR). As a result, CuBpz achieved an impressive faradaic efficiency (FE) of 47.8% for yielding acetate with a current density of -200 mA cm-2, while no obvious degradation was observed over 60 hours of continuous operation at a current density of -200 mA cm-2. Mechanism studies revealed that the dicopper site can promote C-C coupling between two C1 intermediates, thereby being conducive to the generation of the key *CH2COOH intermediate.

A Porous π-π Stacking Framework with Dicopper(I) Sites and Adjacent Proton Relays for Electroreduction of CO2 to C2+ Products.

Crystalline porous materials sustained by supramolecular interactions (e.g., π-π stacking interactions) are a type of molecular crystals showing considerable stability, but their applications are rarely reported due to the high difficulty of their construction. Herein, a stable π-π stacking framework formed by a trinuclear copper(I) compound [Cu3(HBtz)3(Btz)Cl2] (CuBtz, HBtz = benzotriazole) with pyrazolate-bridged dicopper(I) sites is reported and employed for electrochemical CO2 reduction, showing an impressive performance of 73.7 ± 2.8% Faradaic efficiency for C2+ products [i.e., ethylene (44%), ethanol (21%), acetate (4.7%), and propanol (4%)] with a current density of 7.9 mA cm-2 at the potential of -1.3 V versus RHE in an H-type cell and a Faradic efficiency (61.6%) of C2+ products with a current density of ≈1 A cm-2 and a reaction rate of 5639 µmol m-2 s-1 at the potential of -1.6 V versus RHE in a flow cell device, representing an impressive performance reported to date. In-situ infrared spectroscopy, density functional theory calculations, and control experiments revealed that the uncoordinated nitrogen atoms of benzotriazolates in the immediate vicinity can act as proton relays and cooperate with the dicopper(I) site to promote the hydrogenation process of the *CO intermediate and the C-C coupling, resulting in the highly selective electroreduction of CO2 to C2+ products.

Genome-Wide Analysis of the Peptidase M24 Superfamily in Triticum aestivum Demonstrates That TaM24-9 Is Involved in Abiotic Stress Response.

The peptidase M24 (Metallopeptidase 24, M24) superfamily is essential for plant growth, stress response, and pathogen defense. At present, there are few systematic reports on the identification and classification of members of the peptidase M24 proteins superfamily in wheat. In this work, we identified 53 putative candidate TaM24 genes. According to the protein sequences characteristics, these members can be roughly divided into three subfamilies: I, II, III. Most TaM24 genes are complex with multiple exons, and the motifs are relatively conserved in each sub-group. Through chromosome mapping analysis, we found that the 53 genes were unevenly distributed on 19 wheat chromosomes (except 3A and 3D), of which 68% were in triads. Analysis of gene duplication events showed that 62% of TaM24 genes in wheat came from fragment duplication events, and there were no tandem duplication events to amplify genes. Analysis of the promoter sequences of TaM24 genes revealed that cis-acting elements were rich in response elements to drought, osmotic stress, ABA, and MeJA. We also studied the expression of TaM24 in wheat tissues at developmental stages and abiotic stress. Then we selected TaM24-9 as the target for further analysis. The results showed that TaM24-9 genes strengthened the drought and salt tolerance of plants. Overall, our analysis showed that members of the peptidase M24 genes may participate in the abiotic stress response and provided potential gene resources for improving wheat resistance.

Current advances in environmental stimuli regulating the glycyrrhizic acid biosynthesis pathway.

Glycyrrhizic acid, the main active ingredient of licorice, has good antibacterial, anti-tumor, anti-viral, anti-inflammatory, and immunostimulatory activities. However, the content of glycyrrhizic acid fluctuates greatly in different licorice cultivars, and production depends on plant sources, which greatly limits its development and applications. Therefore, increasing glycyrrhizic acid content has become a research priority. In recent years, regulation of the glycyrrhizic acid biosynthesis pathway has been analyzed, the downstream synthesis pathway in licorice has been fully investigated, some key genes have been cloned, polymorphisms have been studied, and the content of glycyrrhizic acid was shown to be regulated by environmental stimuli. This work has provided a basis for studying the regulation mechanism of the glycyrrhizic acid synthesis pathway. This review summarizes and discusses relevant research to provide a current understanding of the glycyrrhizic acid synthesis pathway and its regulation in licorice.