Applied Biochemistry and Biotechnology最新文献

Spironolactone (SPR), a widely used potassium-sparing diuretic, frequently causes hyperkalemia, leading to significant cardiovascular and neurological complications. Taurine, a semi-essential amino acid with known antioxidant and neuroprotective effects, was hypothesized to mitigate these adverse effects. This study investigated taurine's efficacy against SPR-induced hyperkalemia and associated cognitive dysfunction in a rat model. Adult male Sprague-Dawley rats were treated for four weeks with SPR, SPR + galantamine (an AChE inhibitor widely used in the treatment of Alzheimer's disease), or SPR + varying concentrations of taurine, followed by assessment of cognitive, biochemical, and histopathological alterations. SPR administration significantly increased serum potassium levels (~7.5 mEq/L), induced cognitive deficits, disrupted neurotransmitter balance (e.g., altered GABA and glutamate levels), and caused reactive astrocytic swelling in key brain regions. Taurine demonstrated a dose-dependent protective effect against SPR-induced neurotoxicity by mitigating hyperkalemia and associated cognitive impairments. Biochemically, taurine restored neurotransmitter balance by increasing GABA and reducing the excitotoxic glutamate levels. Histological analysis further confirmed taurine's neuroprotective effects, showing preserved cortical structures and reduced astrogliosis, especially at the highest concentration (5%). Our correlation analysis reveals complex regulatory mechanisms underlying neurotransmitter balance in the brain. These findings suggest taurine as a promising therapeutic agent for alleviating SPR-induced neurological side effects. Further studies are needed to explore taurine's long-term effects and clinical applications in managing hyperkalemia-related cognitive dysfunctions.

Squalene epoxidase (SE) is located in the microsomes of the endoplasmic reticulum and acts as a biocatalyst in the biological process where squalene is converted into 2,3-oxidosqualene (MOS). As a precursor for the biosynthesis pathways of important secondary metabolites such as triterpenes, the catalytic efficiency of SE influences the biosynthetic efficiency of these triterpenes by affecting the synthesis of MOS. Therefore, SE is considered a key biological component in the triterpene biosynthesis pathway, and SE from various organisms has been widely studied. By summarizing the bioinformatics analysis, crystal structure, mechanism of action, gene function analysis, and mechanisms in human diseases related to squalene epoxidase, this review provides insights for future research on SE and its associated metabolic products.

Acupuncture, a traditional Chinese medical intervention, is extensively utilized in the management of ischemic stroke across its various stages. However, the precise mechanisms underlying its therapeutic action are not fully elucidated. The present study sought to investigate the therapeutic effects and unravel the potential mechanisms of Xingnao Kaiqiao (XNKQ) acupuncture in ameliorating cerebral ischemia-reperfusion injury (CIRI). We established a rat model of middle cerebral artery occlusion (MCAO) and administered both Xingnao Kaiqiao (XNKQ) acupuncture and non-acupoint acupuncture as interventions. Neurobehavioral scoring and TTC staining were employed to evaluate the efficacy of acupuncture in improving CIRI. Our findings indicated that XNKQ acupuncture significantly enhanced neurological function and decreased the volume of cerebral infarction in rats. Western blot, quantitative real-time PCR (RT-qPCR), dot blot, and kit assays were utilized to assess the impact of acupuncture on ferroptosis and m6A methylation. The data revealed that XNKQ acupuncture diminished the levels of ACSL4 and the ferroptosis-associated markers MDA and Fe²⁺, concurrently reducing global m6A levels and selectively upregulating FTO expression. Subsequently, FTO overexpression and knockdown vectors were administered to MCAO rats, and the interaction between FTO and ACSL4 was confirmed through bioinformatics analysis and methylated RNA immunoprecipitation (MeRIP). The outcomes demonstrated that FTO could modulate the expression of ACSL4 by regulating the m6A methylation of ACSL4 mRNA. Further acupuncture interventions revealed that acupuncture suppresses ACSL4 expression by increasing FTO expression, thereby reducing m6A methylation of ACSL4, downregulating MDA and Fe²⁺ levels, and inhibiting ferroptosis. Collectively, these results suggest that acupuncture mitigates CIRI by modulating the upregulation of FTO, leading to reduced m6A levels of ACSL4 and the inhibition of ferroptosis.

Oxidative stress-induced vascular smooth muscle cell (VSMC) apoptosis plays a central role in aortic aneurysm (AA) progression. In this study, we developed N, Ce-codoped carbon dots (N, Ce-CDs, ~ 4.8 nm) as an efficient nanozyme to counteract this process. The synthesized N, Ce-CDs exhibited superior •OH radical scavenging capability and excellent biocompatibility. In vitro, N, Ce-CDs showed no cytotoxicity toward MOVAS cells, maintaining over 90% cell viability after 72 h exposure. More importantly, they demonstrated a significant protective effect against H₂O₂-induced oxidative damage. The nanozymes alleviated oxidative damage by scavenging intracellular reactive oxygen species (ROS), suppressing lipid peroxidation, and boosting endogenous antioxidant capacity through elevated levels of glutathione (GSH) and enhanced activities of superoxide dismutase (SOD) and catalase (CAT). Furthermore, N,Ce-CDs ‌significantly mitigated H₂O₂-induced damage, recovering ~ 60% of the lost mitochondrial membrane potential (MMP) and reducing the apoptosis rate from 31.97% to 18.52%. These findings highlight the potential of N, Ce-CDs as a multifunctional nanotherapeutic agent that protects VSMCs by integrating antioxidant defense with mitochondrial stabilization, presenting a novel strategy for AA treatment.

This study introduces an innovative enzyme-free DNA circuit system for the simultaneous detection of two distinct nucleic acid biomarkers using a single colorimetric output with four discrete intensity levels. The system integrates toehold-mediated strand displacement (TMSD) and catalytic hairpin assembly (CHA) to generate diagnostic signals based on G-quadruplex structures. Two logic gates, ABC and DE, are designed to respond differentially to inputs: the ABC gate disassembles two G-quadruplexes upon recognition of Input 1, while the DE gate forms a G-quadruplex in response to Input 2. This configuration yields four unique output states corresponding to distinct input combinations. The circuit achieves high sensitivity, with detection limits of 5 pM for Input 1 and 1 pM for Input 2, and displays strong specificity against non-target DNA sequences. Validation in complex biological matrices confirmed the robustness of the system: it maintained 85 ± 3% signal in 50% human serum, indicating high compatibility with clinical sample environments. By employing a single output signal format, the approach simplifies data interpretation, reduces processing time, and enhances cost-effectiveness compared to conventional multi-signal platforms. As an automated, enzyme-free, and one-step detection system, this platform offers a powerful tool for accurate and efficient multiplex biomarker analysis, with promising applications in early disease diagnosis and point-of-care testing.

The rise of antimicrobial resistance (AMR) necessitates novel natural therapeutics. Combining plant extracts offers a promising strategy to enhance antibacterial efficacy via synergistic, multi-target interactions. Bauhinia kockiana, a medicinal vine traditionally used for various treatments, exhibits promising antimicrobial properties, yet the synergistic potential of its multi-organ extracts remains unexplored. This study evaluated the phytochemical profiles and antibacterial activities of aqueous extracts against Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa. Liquid chromatography-mass spectrometry (LC-MS) and Fourier-transform infrared spectroscopy (FTIR) identified 10 organ-specific bioactive phytocompounds and characterized their functional groups. The flower extracts demonstrated the highest total phenolic and flavonoid contents, correlating with superior antibacterial activity. Disc diffusion assays revealed concentration-dependent effects, with flower extracts outperforming streptomycin against MRSA. Minimum inhibitory concentrations (MICs) ranged from 0.125 - 0.5% w/v, with flower extracts showing bactericidal effects against MRSA and P. aeruginosa. Checkerboard assays and well diffusion assays confirmed synergistic flower-stem interactions across multiple pathogens. This combination significantly inhibited S. aureus biofilm formation (> 50% at sub-MIC, complete at 2MIC) and induced morphological deformation. Time-kill kinetics confirmed concentration-dependent bactericidal effects, and mechanistic studies indicated membrane disruption as a primary mode of action, evidenced by enhanced cytoplasmic and protein leakage. These findings highlight the therapeutic potential of B. kockiana multi-organ extracts for combinatorial strategies to combat AMR sustainably.

Biological synthesis of nanoparticles provides an eco-friendly method for producing bioactive materials characterized by low toxicity and enhanced bioavailability. In this study, selenium nanoparticles (SeNPs) were synthesized using the viable cell filtrate of Staphylococcus haemolyticus. Biosynthesis with bacterial cell filtrate uses extracellular enzymes, proteins, and metabolites as reducing and capping agents to convert a selenium precursor (commonly sodium selenite, Na₂SeO₃) into elemental selenium nanoparticles (Se⁰). Advantages include mild conditions, eco-friendliness, and often improved biocompatibility. Characterized by UV-Vis spectroscopy, X-ray diffraction (XRD), atomic force microscopy (AFM), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), and zeta potential analysis. The antimicrobial potential of SeNPs was assessed against biofilm-forming Staphylococcus aureus using a microdilution MIC assay. The SeNPs exhibited broad-spectrum activity, effectively inhibiting Gram-positive and Gram-negative bacteria, as well as Candida species. They also demonstrated strong antioxidant activity and low cytotoxicity, highlighting their safety profile. Furthermore, synergistic assays revealed that combining SeNPs with conventional antimicrobials enhanced their inhibitory effects, including against multidrug-resistant strains. At the molecular level, the clfB gene was detected by PCR, and real-time PCR revealed significant modulation of its expression following SeNP treatment, suggesting interference with biofilm formation. Cytotoxicity assays further indicated that SeNPs exhibited low toxicity toward normal fibroblast (HdFn) cells while showing improved anticancer activity against PC3 cells compared to free drug or neat selenium nanoparticles.

Gestational diabetes mellitus (GDM) is a common metabolic disorder that affects maternal and fetal health. O-GlcNAcylation is increased in GDM and disrupts placental homeostasis. This study aimed to explore the role of O-GlcNAcylation in GDM progression and the underlying mechanism. Trophoblast cell line (HTR-8/SVneo) was treated with high glucose (HG) to assess a cell model. Ferroptosis was evaluated by lipid reactive oxygen species (ROS), malondialdehyde, Fe2+, and glutathione concentrations. The GDM mouse model was established, and blood glucose and blood lipid were measured. The effect of OGT on ELP3 O-GlcNAcylation was measured using immunoprecipitation and western blotting. The results showed that ferroptosis was involved in HG-induced cell injury, and OGT expression was increased in these cells (over 3-fold). Knockdown of OGT inhibited HG-induced ferroptosis in vitro (P < 0.01), and reduced blood glucose (P < 0.01), blood lipid (P < 0.01), and ferroptosis (P < 0.01) in GDM mice. Moreover, silencing of OGT reduced ELP3 protein stability (P < 0.01) via inhibiting ELP3 O-GlcNAcylation at Ser408 site. Overexpression of ELP3 abrogated the inhibition of ferroptosis in HG-induced cells caused by OGT knockdown (P < 0.01). In conclusion, silencing of OGT inhibits trophoblast ferroptosis by suppressing O-GlcNAcylation of ELP3, thereby ameliorating GDM. The findings suggest that targeting OGT-mediated O-GlcNAcylation may be a promising strategy for GDM treatment.