Protective effect and mechanism of procyanidin B2 against hypoxic injury of cardiomyocytes.

Background: Cardiomyocyte ischemia and hypoxia are important causes of oxidative stress damage and cardiomyocyte apoptosis in coronary heart disease (CHD). Epidemiological investigation has shown that eating more plant-based foods, such as vegetables and fruits, may significantly decrease the risk of CHD. As natural antioxidants, botanicals have fewer toxic side effects than chemical drugs and have great potential for development. Procyanidin B2 (PB2) is composed of flavan-3-ol and epicatechin and has been reported to have antioxidant and anti-inflammatory effects. However, whether PB2 exerts protective effects on hypoxic cardiomyocytes has remained unclear. This study aimed to explore the protective effect of PB2 against cardiomyocyte hypoxia and to provide new treatment strategies and ideas for myocardial ischemia and hypoxia in CHD. Methods and results: A hypoxic cardiomyocyte model was constructed, and a CCK-8 assay proved that PB2 had a protective effect on cardiomyocytes in a hypoxic environment. DCFH fluorescence staining, DHE staining, and BODIPY lipid oxidation assessment revealed that PB2 reduced the oxidative stress levels of cardiomyocytes under hypoxic conditions. TUNEL staining, Annexin V/PI fluorescence flow cytometry, and Western blot analysis of the expression of the apoptosis marker protein cleaved caspase-3 confirmed that PB2 reduced cardiomyocyte apoptosis under hypoxic conditions. JC-1 staining indicated that PB2 reduced the mitochondrial membrane potential of cardiomyocytes under hypoxia. In addition, transcriptomic analysis proved that the expression of 158 genes in cardiomyocytes was significantly changed after PB2 was added during hypoxia, of which 53 genes were upregulated and 105 genes were downregulated. GO enrichment analysis demonstrated that the activity of cytokines, extracellular matrix proteins and other molecules was changed significantly in the biological process category. KEGG enrichment analysis showed that the IL-17 signaling pathway and JAK-STAT signaling pathway underwent significant changes. We also performed metabolomic analysis and found that the levels of 51 metabolites were significantly changed after the addition of PB2 to cardiomyocytes during hypoxia. Among them, 39 metabolites exhibited increased levels, while 12 metabolites exhibited decreased levels. KEGG enrichment analysis showed that cysteine and methionine metabolism, arginine and proline metabolism and other metabolic pathways underwent remarkable changes. Conclusion: This study proves that PB2 can reduce the oxidative stress and apoptosis of cardiomyocytes during hypoxia to play a protective role. Transcriptomic and metabolomic analyses preliminarily revealed signaling pathways and metabolic pathways that are related to its protective mechanism. These findings lay a foundation for further research on the role of PB2 in the treatment of CHD and provide new ideas and new perspectives for research on PB2 in the treatment of other diseases.

A Multi-Dimensional Calibration Based on Genetic Algorithm in a 12-Bit 750 MS/s Pipelined ADC.

As the preferred architecture for high-speed and high-resolution analog-to-digital converters (ADC), the accuracy of pipelined ADC is limited mainly by various errors arising from multiple digital-to-analog converters (MDAC). This paper presents a multi-dimensional (M-D) MDAC calibration based on a genetic algorithm (GA) in a 12-bit 750 MS/s pipelined ADC. The proposed M-D MDAC compensation model enables capacitor mismatch and static interstage gain error (IGE) compensation on the chip and prepares for subsequent background calibration based on a pseudo-random number (PN) injection to achieve accurate compensation for dynamic IGE. An M-D coefficient extraction scheme based on GA is also proposed to extract the required compensation coefficients of the foreground calibration, which avoids falling into local traps through MATLAB. The above calibration scheme has been verified in a prototype 12-bit 750 MS/s pipelined ADC. The measurement results show that the signal-to-noise and distortion ratio (SNDR) and spurious-free dynamic range (SFDR) are increased from 49.9 dB/66.7 dB to 59.6 dB/77.5 dB with the proposed calibration at 25 °C. With the help of background calibration at 85 °C, the SNDR and SFDR are improved by 3.4 dB and 8.8 dB, respectively.

A 12-Bit 2 GS/s Single-Channel High Linearity Pipelined ADC in 40 nm CMOS.

This paper presents a single-channel 12-bit, 2 GS/s pipelined analog-to-digital converter (ADC) for wideband sampling receivers. The design adopts a novel source follower input buffer with multiple feedback loops to improve sample linearity and extend bandwidth. Additionally, an improved two stages charge pump amplifier topology is introduced, which doubles the Gain Bandwidth Product (GBW) without consuming additional power. To address the back-end ADC and background calibration, a multi-level dither strategy is employed, utilizing a new high-speed and low-cost uniform distribution pseudorandom code generator. The prototype ADC fabricated in 40 nm CMOS process achieves 68.24 dB SFDR up to Nyquist frequency with a sampling rate of 2 GS/s. Measurement results demonstrate a bandwidth exceeding 5 GHz, resulting in a Schreier FOMs of 152.4 dB.

Metabolomic and transcriptomic studies of improvements in myocardial infarction due to Pycr1 deletion.

Myocardial infarction (MI) remains a major challenge to cardiovascular health worldwide, with poor healing leaving a direct impact on patients' quality of life and survival. Metabolic abnormalities after MI are receiving increasing attention. Our previous studies showed that enhancing proline catabolism ameliorates hypoxic damage to myocardial cells; therefore, we sought to determine whether reducing the synthesis of endogenous proline also affects MI. We analysed GEO datasets associated with MI and western blot of mouse heart tissue in an MI model to demonstrate pyrroline-5-carboxylate reductase 1 (Pycr1) expression level after MI. We constructed Pycr1 KO mice by CRISPR/Cas9 technology to explore the effect of Pycr1 gene KO after MI using transcriptomic and metabolomic techniques. In this study, we found reduced mRNA and protein expression levels of Pycr1 in the hearts of mice after MI. We observed that Pycr1 gene KO has a protective effect against MI, reducing the area of MI and improving heart function. Using transcriptomics approaches, we found 215 upregulated genes and 247 downregulated genes after KO of the Pycr1 gene, indicating that unsaturated fatty acid metabolism was affected at the transcriptional level. Metabolomics results revealed elevated content for 141 metabolites and decreased content for 90 metabolites, among which the levels of fatty acids, glycerol phospholipids, bile acids, and other metabolites increased significantly. The changes in these metabolites may be related to the protective effect of Pycr1 KO on the heart after MI. Pycr1 gene KO has a protective effect against MI and our research will lay a solid foundation for the development of future Pycr1-related drug targets.

Nerve Stimulation by Triboelectric Nanogenerator Based on Nanofibrous Membrane for Spinal Cord Injury.

Spinal cord injury (SCI) is a devastating and common neurological disorder that is difficult to treat. The pain can sustain for many years, making the sufferer extremely painful. Nerve stimulation was first reported half a century ago as a treatment for neuropathic pain. Since then, the method of electrical stimulation through leads placed in the epidural space on the dorsal side of the spinal cord has become a valuable therapeutic tool for SCI. But nerve stimulation equipment is expensive, and the stimulator design and treatment plan are complicated, which hinders its development. In recent years, wearable and implantable triboelectric nanogenerators (TENGs) developed rapidly, and their low cost and safety have brought a new turning point for the development of nerve stimulation. Nanofibrous membrane has been proved that it is a flexible material with the advantages of ultrathin diameter, good connectivity, easy scale-up, tunable wettability, fine flexibility, tunable porosity, controllable composition and so on. In this paper, we discuss the technology of using nanofiber membrane on clothing to create TENGs to provide continuous electrical energy for nerve stimulation to treat SCI in patients by analyzing previous research.

PCSK9Qß-003 Vaccine Attenuates Atherosclerosis in Apolipoprotein E-Deficient Mice.

PURPOSE: Our group has developed a therapeutic vaccine targeting proprotein convertase subtilisin/kexin type 9 (PCSK9), named PCSK9Qß-003. In this study, we investigated the potential effectiveness of the PCSK9Qß-003 vaccine on atherosclerosis. METHODS: Male ApoE-/- mice were randomly assigned to three groups: a phosphate-buffered saline (PBS) group, Qß virus-like particles (VLP) group, and PCSK9Qß-003 vaccine group. Mice in the PCSK9Qß-003 group were injected with the PCSK9Qß-003 vaccine four times (100 µg/time) over a period of 18 weeks. The effects of the vaccine on atherosclerotic plaque, cholesterol transport, inflammation and apoptosis were investigated. RESULTS: The PCSK9Qß-003 vaccine obviously decreased total cholesterol and low-density lipoprotein cholesterol in ApoE-/- mice. Compared with the other groups, the PCSK9Qß-003 vaccine significantly reduced the lesion area and promoted the stability of atherosclerotic plaque. The vaccine regulated cholesterol transport in the aorta of ApoE-/- mice by up-regulating the expression level of liver X receptor α and ATP binding cassette transporter A1. Additionally, macrophage infiltration and expression of monocyte chemoattractant protein-1 and tumor necrosis factor-α were significantly decreased in the mice administered the PCSK9Qß-003 vaccine. The vaccine also markedly reduced apoptosis in the lesion area of the aorta in ApoE-/- mice. CONCLUSIONS: The results demonstrated that the PCSK9Qß-003 vaccine attenuated the progression of atherosclerosis by modulating reverse cholesterol transport and inhibiting inflammation infiltration and apoptosis, which may provide a novel therapeutic approach for atherosclerosis and greatly improve treatment compliance among patients.

Vaccine Against PCSK9 Improved Renal Fibrosis by Regulating Fatty Acid ß-Oxidation.

Background Defects in the renal fatty acid ß-oxidation pathway have been implicated in the development of renal fibrosis. Our group has developed a therapeutic vaccine targeting PCSK9 (proprotein convertase subtilisin/kexin type 9), named PCSK9Qß-003. In this study, we investigated the potential effectiveness of the PCSK9Qß-003 vaccine on hypercholesterolemia with renal fibrosis. Methods and Results The low-density lipoprotein receptor+/- male mice fed with a high-cholesterol (1%) Western diet were randomly assigned into 4 groups: the sham group (or the control group), the phosphate-buffered saline group, the Qß virus-like particles group and the PCSK9Qß-003 vaccine group. Mice of the PCSK9Qß-003 group were injected with the PCSK9Qß-003 vaccine (100 µg/time) every 2 or 4 weeks. The mice were administered with either unilateral ureteral obstruction for 2 weeks or N-nitro-l-arginine methyl ester (50 mg/kg per day) for 6 weeks to establish a renal fibrosis model. Compared with the other 3 groups, the PCSK9Qß-003 vaccine obviously decreased total cholesterol and low-density lipoprotein cholesterol in low-density lipoprotein receptor+/- mice with hypercholesterolemia. Compared with the phosphate-buffered saline and Qß virus-like particles groups, the PCSK9Qß-003 vaccine improved hepatic steatosis and renal function. Histology analysis showed that the PCSK9Qß-003 vaccine significantly ameliorated renal lipid accumulation and renal fibrosis. Moreover, the PCSK9Qß-003 vaccine obviously upregulated the expression of low-density lipoprotein receptor, very-low-density lipoprotein receptor, sterol-regulatory element binding protein 2, and fatty acid ß-oxidation-related factors, and ameliorated renal fibrosis-related molecules both in the unilateral ureteral obstruction and N-nitro-l-arginine methyl ester models. Conclusions This study suggested that the PCSK9Qß-003 vaccine improved renal lipid accumulation and renal fibrosis by regulating fatty acid ß-oxidation, which may provide a promising method for treating hypercholesterolemia with renal fibrosis.

Vaccine Targeted Alpha 1D-Adrenergic Receptor for Hypertension.

The α1-AR (α1 adrenergic receptor) blockers currently on the market cannot meet clinical needs because of low-selectivity for subtypes of α1-ARs, short half-life, and uncertain role in cardiovascular end point events. The study sought to find a vaccine specifically against α1D-AR (α1D-adrenergic receptor) for treating hypertension. A short peptide ADR-004 (cgiteeagy) belonging to α1D-AR was screened, and the ADRQß-004 vaccine was produced and injected into spontaneously hypertensive rats model (including a short-term study, 10 weeks, and a long-term observation study, 39 weeks) and NG-nitro-l-arginine methyl ester + spontaneously hypertensive rats model (15 weeks). The antihypertensive effect and target organ protection of the ADRQß-004 vaccine were carefully evaluated. The possible immune-mediated damage was detected in normal vaccinated Sprague Dawley rats. The ADR-004 peptide has perfect immunogenicity, and the ADRQß-004 vaccine could induce strong antibody production. In the short-term study, the ADRQß-004 vaccine averagely decreased the systolic blood pressure of spontaneously hypertensive rats up to 15 mm Hg and that of NG-nitro-l-arginine methyl ester+spontaneously hypertensive rats up to 29 mm Hg. In the long-term observation model, the antihypertensive effect of the ADRQß-004 vaccine was quite stable, and the average decline of systolic blood pressure was 22 mm Hg. The ADRQß-004 vaccine effectively prevented vascular structural remodeling, cardiac hypertrophy and fibrosis, and renal injury of hypertensive animals, superior to prazosin at renal level. Moreover, the ADRQß-004 vaccine obviously downregulated the expression of α1D-AR, but not α1A-AR. Additionally, no significant immune-mediated damage was detected in immunized animals. The present results demonstrate that the ADRQß-004 vaccine may provide a novel and promising method for the treatment of hypertension.