Chronic heart failure (CHF) may be associated with an energy deficit in cardiac muscle. As levo-carnitine (LC) is involved in the production of myocardial energy, it is hypothesized that LC supplementation may ameliorate CHF symptoms. This multicentre, randomized, double-blind, and placebo-controlled study included 265 patients with CHF. Patients were randomized to receive either LC or placebo, twice a day. Endpoints were measured after 7 days of treatment. Primary endpoint was a reduction of at least one NYHA class. Secondary endpoints were changes in 6-min walk distance (6-MWD) compared with baseline, either alone or in combination with NYHA class decrease, left ventricular ejection fraction, and NT-proBNP level, together with adverse events. The primary endpoint was reached in 60.9% of patients treated with LC, compared with only 44.7% of the placebo group (P ¼ 0.012). Among the secondary endpoints, 6-MWD, alone or in combination with NYHA class, improved significantly in the LC group compared with placebo (P ¼ 0.0497 and P ¼ 0.003, respectively). values of plasma-free carnitine were observed in patients with NYHA classes III and IV where the effect of LC supplementation was greatest (P ¼ 0.002). Treatment with LC significantly improved CHF symptoms in Chinese patients, probably by correcting a status of carnitine insufficiency.
microRNAs (miRs) are essential in the development of heart failure. The aim of this study is to investigate the effect of microRNA‐330 (miR‐330) on left ventricular remodeling via the TGF‐β1/Smad3 signaling pathway by targeting the sex‐determining region Y (SRY) in mice with myocardial ischemia–reperfusion injury (MIRI). Differentially expressed gene (DEG) in myocardial ischemia–reperfusion (IR) was screened out and the miR that targeted the DEG was also predicted and verified. A model of MIRI was established to detect the expression of miR‐330, SRY, transforming growth factor‐β (TGF‐β1), and Sekelsky mothers against dpp3 (Smad3). To further investigate the role of miR‐330 in MIRI with the involvement of SRY and TGF‐β1/Smad3 signaling pathway, the modeled mice were treated with different mimic, inhibitor, or small interfering RNA (siRNA) to observe the changes of the related gene expression, as well as the myocardial infarction size and volume of myocardial collagen. SRY was screened out and verified as a target gene of miR‐330. The MIRI mice showed enlarged myocardial infarction size, increased volume of myocardial collagen, increased expression of miR‐330, TGF‐β1 and Smad3, while decreased the expression of SRY. The MIRI mice treated with miR‐330 inhibitor showed decreased myocardial infarction size, the volume of myocardial collagen, and expression of TGF‐β1 and Smad3 but promoted expression of SRY. Our findings demonstrated that downregulated miR‐330 could suppress left ventricular remodeling to inhibit the activation of the TGF‐β1/Smad3 signaling pathway via negatively targeting of SRY in mice with MIRI. This can be a potential target in the strategy to attenuate patient suffering.
Background
A high level of total cholesterol is associated with several lipid metabolism disorders, including atherosclerosis and cardiovascular diseases. ATP-binding cassette (ABC) transporter A1 (ABCA1) and miR-33-5p play crucial roles in atherosclerosis by controlling cholesterol efflux. While citrate is a precursor metabolite for lipid and cholesterol synthesis, little is known about the association between citrate synthase (CS) and cholesterol efflux. This study investigated the role of the miR-33-5p/ABCA1/CS axis in regulating cholesterol efflux in vascular endothelial cells (VECs).
Materials and methods
VECs were treated with oxidized low-density lipoprotein cholesterol (ox-LDL), or pretreated with plasmids overexpressing CS, ABCA1, siRNAs against CS and ABCA1, and an miR-33-5p inhibitor. Cell apoptosis, cellular senescence-associated β-galactosidase activity, inflammation, and cholesterol efflux were detected.
Results
Treatment with ox-LDL decreased ABCA1 and CS levels and increased miR-33-5p expression and apoptosis in dose-dependent manners. In contrast, treatment with the miR-33-5p inhibitor and ABCA1 and CS overexpression plasmids inhibited the above-mentioned ox-LDL-induced changes. In addition, treatment with ox-LDL decreased cholesterol efflux, induced aging, and promoted the production of inflammatory cytokines (i.e., IL-6 and tumor necrosis factor TNF-α), as well as the expression of Bax and Caspase 3 proteins in VECs. All these changes were rescued by miR-33-5p inhibition and ABCA1 and CS overexpression. The inhibition of ABCA1 and CS by siRNAs eliminated the effects mediated by the miR-33-5p inhibitor, and knockdown of CS eliminated the effects of ABCA1 on VECs.
Conclusions
This study demonstrated the crucial roles played by the miR-33-5p/ABCA1/CS axis in regulating cholesterol efflux, inflammation, apoptosis, and aging in VECs, and also suggested the axis as a target for managing lipid metabolism disorders.
Resveratrol (RES) protects myocardial cells from hypoxia/reoxygenation (H/R)-caused injury. However, the mechanism of this effect has not been clarified. Thus, in this study, we aimed to determine whether RES attenuates H/R-induced cell necroptosis by inhibiting the tumor necrosis factor-alpha (TNF-α)/receptor-interacting protein kinase 1 (RIP1)/RIP3/mixed-lineage kinase domain-like (MLKL) signaling pathway. Rat myocardial ischemia/reperfusion (I/R) models and H/R-injured cell models were constructed. Our study showed that myocardial H/R injury significantly increased the levels of TNF-α, RIP1, RIP3, and p-MLKL/MLKL by western blot analysis. Cell viability assay and 4,6-dianmidino-2-phenylindole (DAPI)–propidium iodide staining showed that the cell viability was decreased, and necroptosis was increased after myocardial H/R injury. The expressions of TNF-α, RIP1, RIP3, and p-MLKL/MLKL in H/R myocardial cells treated with different concentrations of RES were significantly downregulated. In addition, we also found that the cell viability was increased and necroptosis was decreased in dose-dependent manners when H/R-injured cells were treated with RES. In addition, the enhanced effect of TNF-α on necroptosis in myocardial H/R-injured cells was improved by RES, and the effect of RES was confirmed in vivo in I/R rats. This study also showed that RES suppresses necroptosis in H9c2 cells, which may occur through the inhibition of the TNF-α/RIP1/RIP3/MLKL signaling pathway. Our data suggest that necroptosis is a promising therapeutic target and may be a promising therapeutic target for the treatment of myocardial I/R injury.
To develop reagents for early diagnosis and therapeutic drugs against SARS-associated coronavirus (SARS-CoV), a large (3 Â 10 9 ) immunized human antibody library was constructed from peripheral blood mononuclear cells from six SARS convalescent patients. A single chain variable fragment antibody (N18) with high affinity against N protein of SARS-CoV was isolated. Sequence analysis revealed that the VL gene was composed of VL3 h (V lambda subgroup) and JL2 regions and the VH gene was composed of VH1-69 (VH1 subgroup), D2-15, D3-22 and JH6 regions. Soluble N18 antibody was expressed in Escherichia coli HB2151, purified by NieNTA affinity chromatography and verified by SDS-PAGE and Western blot. The potential application for early diagnosis was evaluated using N protein capture ELISA in which N18 antibody demonstrated high sensitive activity in detecting N protein of SARS-CoV. Finally, the potential usefulness of the N18 antibody in prophylaxis, vaccine design and therapy of SARS is discussed.
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