Paeoniflorin confers ferroptosis resistance by regulating the gut microbiota and its metabolites in diabetic cardiomyopathy.

Diabetic cardiomyopathy (DCM) is closely related to ferroptosis, a new type of cell death that mainly manifests as intracellular iron accumulation and lipid peroxidation. Paeoniflorin (PA) helps to improve impaired glucose tolerance, influences the distribution of the intestinal flora, and induces significant resistance to ferroptosis in several models. In this study, we found that PA improved cardiac dysfunction in mice with DCM by alleviating myocardial damage, resisting oxidative stress and ferroptosis, and changing the community composition and structure of the intestinal microbiota. Metabolomics analysis revealed that PA-treated fecal microbiota transplantation affected metabolites in DCM mice. Based on in vivo and in vitro experiments, 11,12-epoxyeicosatrienoic acid (11,12-EET) may serve as a key contributor that mediates the cardioprotective and antiferroptotic effects of PA-treated fecal microbiota transplantation (FMT) in DCM mice.NEW & NOTEWORTHY This study demonstrated for the first time that paeoniflorin (PA) exerts protective effects in diabetic cardiomyopathy mice by alleviating myocardial damage, resisting ferroptosis, and changing the community composition and structure of the intestinal microbiota, and 11,12-epoxyeicosatrienoic acid (11,12-EET) may serve as a key contributor in its therapeutic efficacy.

Multi-responsive Pickering emulsifiers: a comprehensive study on the emulsification-demulsification behavior of modified chitosan-coated Fe3O4 nanocomposites.

The surface characteristics of stimuli-responsive Pickering emulsifiers can be modified by external environmental triggers, making them highly versatile in various applications. In this study, we report three novel organic-inorganic composite structure emulsifiers. These emulsifiers were designed with a core of magnetic Fe3O4 particles, surrounded by a protective silica layer, and coated on the exterior with three distinct types of modified chitosan (CS). Experimental results demonstrate that these emulsifiers can stabilize emulsion systems consisting of liquid paraffin and deionized water at a concentration of 0.5 wt%. The unique properties of the modified CS coatings allowed for the controlled demulsification of two types of emulsions by adjusting the proton concentration. Additionally, these emulsifiers exhibited magnetic-responsive demulsification under the control of an external magnetic field. The findings of this study provide valuable insights into the design and construction of multi-responsive chitosan-based magnetic Pickering emulsifiers with controllable properties.

Self-templating synthesis strategy of oxygen-doped carbon from unique wasted pulping liquid directly as a cathode material for high-performance zinc ion hybrid capacitors.

Affinity and storage capacity for zinc ions of the electrode materials are crucial factors on the properties of zinc ion hybrid capacitors (ZHICs). Wasted pulping liquor with abundant carbohydrates, lignin and inorganic matter served as a unique precursor to produce embedded oxygen-doped hierarchical porous carbon directly through a one-step carbonization process in this investigation. In carbonization process, lignin can serve effectively as the carbon framework, carbohydrates not only act as sacrificial templates but also offer a plentiful oxygen source which can increase the affinity for Zn2+, and sodium-containing inorganic substances plays a role as hard templates to optimize the pore structure. The resulting porous carbon under carbonization temperature of 800 °C shows a high specifical area of 2186 m2g-1 with oxygen content of 4.8 %, which can reduce the adsorption energy of Zn2+ from -0.16 eV to -0.32 eV through electrochemical techniques and density functional theory (DFT) calculations, the incorporation of oxygen was demonstrated to enhance the adsorption and desorption kinetics of Zn2+, suggesting a bright future for application in the domain of energy storage. The resulting ZIHC assembly showcases a notable energy density of 84.6 Wh kg-1 at a power density of 359 W kg-1. Remarkably, even after 10,000 charge and discharge cycles, it exhibits exceptional cycle stability with retaining 86.56 % of its capacity. Consequently, this approach provides fresh insights for exploring the facile and commercial fabrication of biomass-derived cathodes for ZIHCs, thereby propelling the progress of eco-friendly energy storage devices.

Double domain fusion improves the reverse transcriptase activity and inhibitor tolerance of Bst DNA polymerase.

To enhance the DNA/RNA amplification efficiency and inhibitor tolerance of Bst DNA polymerase, four chimeric Bst DNA polymerase by fusing with a DNA-binding protein Sto7d and/or a highly hydrophobic protein Hp47 to Bst DNA polymerase large fragment. One of chimeric protein HpStBL exhibited highest inhibitor tolerance, which retained high active under 0.1 U/µL sodium heparin, 0.8 ng/µL humic acid, 2.5× SYBR Green I, 8 % (v/v) whole blood, 20 % (v/v) tissue, and 2.5 % (v/v) stool. Meanwhile, HpStBL showed highest sensitivity (93.75 %) to crude whole blood infected with the African swine fever virus. Moreover, HpStBL showed excellent reverse transcriptase activity in reverse transcription loop-mediated isothermal amplification, which could successfully detect 0.5 pg/µL severe acute respiratory syndrome coronavirus 2 RNA in the presence of 1 % (v/v) stools. The fusion of two domains with different functions to Bst DNA polymerase would be an effective strategy to improve Bst DNA polymerase performance in direct loop-mediated isothermal amplification and reverse transcription loop-mediated isothermal amplification detection, and HpStBL would be a promising DNA polymerase for direct African swine fever virus/severe acute respiratory syndrome coronavirus 2 detection due to simultaneously increased inhibitor tolerance and reverse transcriptase activity.

Total Biosynthesis of Circular Bacteriocins by Merging the Genetic Engineering and Enzymatic Catalysis.

Circular bacteriocins are known for their structural stability and effective antimicrobial properties, positioning them as potential natural food preservatives. However, their widespread application is impeded by restricted availability. This research developed a total biosynthesis platform for circular bacteriocins, with a focus on AS-48 by involving recombinant production of the linear precursor in Escherichia coli, followed by enzymatic cyclization of the precursor into cyclic AS-48 using the ligase butelase-1 in vitro. An important discovery is that, aside from fusion tags, the C-terminal motif LE and LEKKK also could affect the expression yield of the precursor. This biosynthesis platform is both versatile and high-yielding, achieving yields of 10-20 mg/L of AS-48. Importantly, the biosynthetic AS-48 exhibited a secondary structure and antimicrobial activities comparable to those of the native molecules. As such, this work proposes an effective synthetic approach for circular bacteriocins, facilitating their advancement and application in the food industry.

Temperature-responsive salt-resistant poly(sulfobetaine methacrylate)-based emulsifiers for heavy oils.

The emulsions prepared with most currently reported emulsifiers are stable only at room temperature and are susceptible to demulsification at higher temperatures. This thermal instability prevents their use in high-temperature and high-salt environments encountered oilfield extraction. To address this issue, in this study, two temperature-responsive emulsifiers, PSBMA and CS-PSBMA, were synthesized. Both emulsifiers exhibited the ability to form stable emulsions within the temperature range of 60-80 °C and undergo demulsification at 20-40 °C. A comprehensive investigation was conducted to assess the impact of emulsifier concentration, water-to-oil ratio, and salt ion concentration on the stability of emulsions formed by these two emulsifiers. The results demonstrated their remarkable emulsification capabilities across diverse oil phases. Notably, the novel emulsifier CS-PSBMA, synthesized through the grafting chitosan (CS) onto PSBMA, not only exhibits superior emulsion stability and UCST temperature responsiveness but also significantly enhanced the salt resistance of the emulsion. Remarkably, the emulsion maintained its stability even in the presence of monovalent salt ions at concentrations up to 2 mol/L (equivalent to a mineralization level of 1.33 × 105 mg/L in water) and divalent salt ions at concentrations up to 3 mol/L (equivalent to a mineralization level of 2.7 × 105 mg/L in water). The emulsions stabilized by both emulsifiers are resilient to harsh reservoir conditions and effectively emulsify heavy oils, enabling high-temperature emulsification and low-temperature demulsification. These attributes indicate their promising potential for industrial applications, particularly in the field of enhanced oil recovery.

"Top-down" overexpression optimization of butelase-1 in Escherichia coli and its application in anti-tumor peptides.

Butelase-1, the fastest known Asn/Asp-specific peptide ligase capable of catalyzing peptide ligation and cyclization, holds promising application prospects in the fields of food and biology. However, limited research exists on its recombinant expression and potential applications in peptide drugs. In this study, the activity of recombinantly-produced butelase-1 was enhanced by co-expressing it with a molecular chaperone in the SHuffle T7 strain. By introducing single or multiple synonymous rare codons at the beginning of the coding regions of beta-strand or alpha-helix, in combination with ribosomal binding site engineering, the activity of butelase-1 could be further improved. Consequently, the butelase-1 with a specific activity of 386.93 U/mg and a catalytic efficiency of 11,048 M-1 s-1 was successfully prepared in E. coli, resulting in a total activity of 8183.54 U/L and a yield of about 100 mg/L. This optimized butelase-1 was then used to efficiently cyclize the redesigned anti-cancer peptide lunasin, leading to enhanced bioavailability and anti-cancer effects. Overall, this study not only provided valuable biotechnology strategies for improving the recombinant expression of butelase-1 but also demonstrated a successful application for enhancing the biological efficacy of anti-cancer peptides.

Blood lipid levels mediating the effects of sex hormone-binding globulin on coronary heart disease: Mendelian randomization and mediation analysis.

Observational studies indicate that serum sex hormone-binding globulin (SHBG) levels are inversely correlated with blood lipid levels and coronary heart disease (CHD) risk. Given that dyslipidemia is an established risk factor for CHD, we aim to employ Mendelian randomization (MR) in conjunction with mediation analysis to confirm the mediating role of blood lipid levels in the association between SHBG and CHD. First, we assessed the causality between serum SHBG levels and five cardiovascular diseases using univariable MR. The results revealed causality between SHBG levels and reduced risk of CHD, myocardial infarction, as well as hypertension. Specifically, the most significant reduction was observed in CHD risk, with an odds ratio of 0.73 (95% CI 0.63-0.86) for each one-standard-deviation increase in SHBG. The summary-level data of serum SHBG levels and CHD are derived from a sex-specific genome-wide association study (GWAS) conducted by UK Biobank (sample size = 368,929) and a large-scale GWAS meta-analysis (60,801 cases and 123,504 controls), respectively. Subsequently, we further investigated the mediating role of blood lipid level in the association between SHBG and CHD. Mediation analysis clarified the mediation proportions for four mediators: high cholesterol (48%), very low-density lipoprotein cholesterol (25.1%), low-density lipoprotein cholesterol (18.5%), and triglycerides (44.3%). Summary-level data for each mediator were sourced from the UK Biobank and publicly available GWAS. The above results confirm negative causality between serum SHBG levels and the risk of CHD, myocardial infarction, and hypertension, with the causal effect on reducing CHD risk largely mediated by the improvement of blood lipid profiles.

Baicalin Attenuates Diabetic Cardiomyopathy In Vivo and In Vitro by Inhibiting Autophagy and Cell Death Through SENP1/SIRT3 Signaling Pathway Activation.

Aims: Diabetic heart damage can lead to cardiomyocyte death, which endangers human health. Baicalin (BAI) is a bioactive compound that plays an important role in cardiovascular diseases. Sentrin/SUMO-specific protease 1 (SENP1) regulates the de-small ubiquitin-like modifier (deSUMOylation) process of Sirtuin 3 (SIRT3) and plays a crucial role in regulating mitochondrial mass and preventing cell injury. Our hypothesis is that BAI regulates the deSUMOylation level of SIRT3 through SENP1 to enhance mitochondrial quality control and prevent cell death, ultimately improving diabetic cardiomyopathy (DCM). Results: The protein expression of SENP1 decreased in cardiomyocytes induced by high glucose and in db/db mice. The cardioprotective effects of BAI were eliminated by silencing endogenous SENP1, whereas overexpression of SENP1 showed similar cardioprotective effects to those of BAI. Furthermore, co-immunoprecipitation experiments showed that BAI's cardioprotective effect was due to the inhibition of the SUMOylation modification level of SIRT3 by SENP1. Inhibition of SENP1 expression resulted in an increase in SUMOylation of SIRT3. This led to increased acetylation of mitochondrial protein, accumulation of reactive oxygen species, impaired autophagy, impaired mitochondrial oxidative phosphorylation, and increased cell death. None of these changes could be reversed by BAI. Conclusion: BAI improves DCM by promoting SIRT3 deSUMOylation through SENP1, restoring mitochondrial stability, and preventing the cell death of cardiomyocytes. Innovation: This study proposes for the first time that SIRT3 SUMOylation modification is involved in the development of DCM and provides in vivo and in vitro data support that BAI inhibits cardiomyocyte ferroptosis and apoptosis in DCM through SENP1. [Figure: see text].