Applied Biochemistry and Biotechnology最新文献

The biological role of SOX9 in biliary atresia (BA) and the underlying mechanisms were unknown, and these were explored in this study. A BA mouse model and TGF-β-treated LX-2 cells were employed for the in vivo and in vitro experiments. QRT-PCR and western blot were employed to examine mRNA expression and protein level; colorimetric kits were employed to detect serum ALT and AST in mice; hematoxylin-eosin (HE) and Masson staining were employed to assess the pathological changes of liver tissues; different assay kits were employed to assess malondialdehyde (MDA), glutathione (GSH), ROS, and Fe²⁺ concentration. Our results revealed that significantly increased SOX9 and TGF-β were observed in the serum of BA children, and significantly increased SMAD3 and decreased FXR were observed in the liver tissues of BA children. Also, SOX9 deletion alleviated liver fibrosis and inhibited ferroptosis in BA mice. The in vitro experiments further revealed that FXR overexpression or SMAD3 deletion down-regulated SOX9 expression to inhibit ferroptosis in TGF-β-treated LX-2 cells, which may depend on the interaction between SOX9 and SLC7A11. This study may provide novel insight into the pathogenesis of BA as well as a new treatment strategy.

To enhance the activity of polysaccharides, the method of ultrasound-assisted pectinase was adopted in this experiment to obtain Lizhi seed polysaccharide (LSP). And the derivatization of LSP was carried out by using the acetic anhydride method, chloroacetic acid carboxymethylation method, and phosphorus oxychloride phosphorylation method. The antioxidant activity of the obtained acetylated polysaccharide (Ac-LSP), carboxymethylated polysaccharide (CM-LSP), and phosphorylated polysaccharide (P-LSP), respectively, was investigated. The results showed that CM-LSP had good efficacy in antilipid and scavenging hydroxyl radicals, and its activity was even better than that of LSP and LSP-2. To explore the elaborate structure of LSP, pure LSP-2 was obtained by using diethylaminoethyl (DEAE)-52 cellulose column chromatography and Sephadex G-100 gel column chromatography in this experiment. The Congo red experiment on LSP-2 revealed that it did not possess a triple helix structure. Subsequently, infrared and nuclear magnetic resonance (NMR) analyses were performed on LSP-2, and it was found that LSP-2 had five sugar residues. The sugar residues contained α-1,3-, α-1,4-, and α-1,6-glycosidic bonds. Among them, there was also a furan type with β-1,4 and β-1,6 reducing aldose residues. Therefore, in general, this experiment achieved a high degree of purification of LSP, explored the rich structure of LSP-2, found the optimal conditions for the derivatization of LSP, and enhanced the antioxidant activity of LSP.

Redox mediators (RMs) have been widely employed in bioelectrochemical systems to enhance electron transfer efficiency. However, systematic comparisons of RM-driven microbial selectivity and its direct correlation with methane production in microbial electrolysis cells (MECs) remain unexplored. This study investigates methane production in MECs using carbon felt (CF) electrodes modified with four RMs, i.e., neutral red (NR), anthraquinone-2,6-disulfonic acid disodium salt (AQDS), humic acid (HA), methyl viologen (MV), and the conductive polymer polyaniline (PANI). Cyclic voltammetry and electrochemical impedance spectroscopy revealed superior electrochemical activity for NR- and HA-modified electrodes (CF-NR, CF-HA) among the tests. CF-NR and CF-PANI demonstrated the highest biocompatibility, supporting 25% and 15% greater biofilm biomass than unmodified CF, respectively. Modified electrodes exhibited lower alpha diversity than CF, indicating enhanced selectivity in microbial enrichment. Overall, CF-HA achieved the highest methane yield (304.1 mL CH₄/g COD), ~20% higher than the CF control. This study demonstrates that modification-specific microbial enrichment critically governs MEC performance, whereas the quantity of biomass adhesion to the electrode is not the determining factor.

Nanobiohybrid systems are innovative platforms that integrate biological macromolecules with nanomaterials to form hybrid structures. These systems have diverse applications, including gene delivery, cancer therapy, drug delivery, biosensing, and diagnostics. Specifically, for gene delivery, nanobiohybrid systems are designed to improve the transport of genetic material to target cells by protecting the material, enabling its passage across biological barriers, and accurately targeting specific cells. Here, a targeted gene delivery system based on the mannosylated carbon quantum dots (Man-CQDs) and a chimeric peptide (Pep) was developed to condense and deliver DNA into the antigen presenting cells. The nanobiohybrid complex formation was studied by spectroscopic methods, microscale thermophoresis (MST), dynamic light scattering, transmission electron microscopy, and gel retardation assay. The blue-emitting Pep/DNA/Man-CQDs nanohybrids exhibited a size of 16 ± 2 nm and a zeta potential of - 12.6 mV. Molecular dynamics simulations revealed that Man-CQDs preferentially interact with DNA within the Pep/DNA complex, supporting MST results which confirmed binding between Man-CQDs and the Pep/DNA complex (Kd = 15.6 µM), but not with the peptide alone. Gene transfection efficiency of the developed nanobiohybrid system was confirmed on J744A.1 macrophages. Additionally, MD simulations of the Pep/DNA/Man-CQDs complex revealed that Man-CQDs predominantly bind to the DNA component, primarily through π-π interactions between Man-CQDs and the unsaturated (poly)cyclic moieties in GC-rich regions of the DNA. The interactions between the chimeric peptide and DNA are largely driven by electrostatic forces, with coulombic energy being 3.9-fold higher than noncoulombic energy. These forces arise from the positively charged amino acids of the peptide and the negatively charged backbone of the DNA.

In situ reintegration of crude glycerol into lipid feedstock can increase the production efficiency and environmental tolerance for the biodiesel industry. In this study, a wild oleaginous yeast Rhodosporidium toruloides CGMCC 2.1389 was selected for its high cell growth and lipid accumulation in crude glycerol. Ultra-centrifugal fractionation was applied in a long-term adaptive evolution, and a stable R. toruloides XR20 strain was finally obtained. The lipid content and titer of the R. toruloides XR20 strain in flask increased by 100.1% and 75.8% compared with the parental strain. Record-breaking lipid titers using crude glycerol by R. toruloides XR20 were achieved by batch and fed-batch fermentation, reaching 24.5 ± 0.5 g/L and 42.5 ± 0.8 g/L, respectively. R. toruloides XR20 showed enlarged intracellular space, higher intracellular NADPH, and acetyl-CoA contents compared with the parental strain. The changes in the expression levels of the key genes favored lipid synthesis in R. toruloides XR20. This study constructed a robust high lipid-producing R. toruloides on crude glycerol, contributing to a glycerol-free biodiesel production process.

Essential oils (EO) are plants' secondary metabolites significant for plant defense and supplementary growth. These are synthesized in plant cells in response to various factors. Here, we demonstrate that essential oils extracted from the leaves of Curcuma longa are differentially expressed at different developmental stages. The EO yield was 1.13% at 4 months old, 1.79% at 6 months, and 1.35% at 8 months old leaf in the Rajendra Sonali variety. In the variety Narendra Haldi, the essential oils yield was 0.81% at 4 months old, 1.75% at 6 months, and 1.08% at 8 months old leaf. The number of compounds was 45, 41, and 42 in Rajendra Sonali and 47, 33, and 40 in Narendra Haldi leaves at 4, 6, and 8 months old leaves. Monoterpenes were the most abundant, followed by sesquiterpenes. Terpinolene accounts for the highest component at 27.62%, 38.86%, and 24.7% in the Rajendra variety, while it is 30.57%, 36.01%, and 11.36% in Narendra Haldi (NH) at three different stages. Differential gene expression showed that genes involved in the biosynthesis of essential oils were highly expressed in 6-month old leaves. Most of the genes that act as feeder pathways to EO biosynthesis, such as carbohydrate metabolism, are highly expressed in 6-month old leaves. The findings suggest that the essential oil content and chemical composition are due to the differential expression of genes involved in the essential oil biosynthetic pathway, and the differential components may be used as a metabolic marker of developmental stages.

The escalating demand for effective and sustainable photoprotection has driven innovation in the sunscreen industry. This review highlights the unique strengths of algae-derived bioactive compounds-including mycosporine-like amino acids, carotenoids, and scytonemin-as next-generation, eco-friendly alternatives to conventional chemical sunscreens. Unlike previous studies, our work provides a comparative analysis of the photoprotective mechanisms, photostability, and multifunctional skin benefits of algal compounds, integrating recent advances in laboratory research and commercial applications. We also critically assess the commercial viability and environmental sustainability of algae-based sunscreens, drawing on current market trends and industry data. By synthesizing these findings, this review underscores the potential of algae-derived ingredients to revolutionize the photoprotective skincare market, offering superior efficacy, safety, and ecological benefits. Our analysis provides actionable insights for researchers and industry stakeholders seeking to advance sustainable skincare solutions.

Uridine diphosphate glycosyltransferases (UGTs) play crucial roles in the glycosylation of plant metabolites, contributing to growth, defense, and stress adaptation. Despite their importance, UGT functions in Glycyrrhiza remain poorly understood, particularly in stress responses and xenobiotic metabolism. In this study, we report the cloning and functional characterization of GgUGT72Z7, a 1413 bp gene encoding a flavonol 3-O-glucosyltransferase that shares 74% sequence identity with Glycine max UGT72Z3. Structural modeling (AlphaFold, SWISS-MODEL, Phyre2) and molecular docking identified azadirachtin, a pharmacologically active tetranor-triterpenoid, as the most favorable ligand (binding energy -15 kcal/mol). In vitro enzymatic assays with recombinant protein validated its ability to glycosylate azadirachtin, a bioactive limonoid found in the seeds of the neem tree (Azadirachta indica) besides native flavonoids, kaempferol and quercetin. Among the models, the AlphaFold structure showed the best structural quality, highlighting interactions between azadirachtin and five key residues (Ser-249, Glu-370, Glu-251, Lys-53, Ala-348). Expression profiling demonstrated strong induction of GgUGT72Z under senescence (1136-fold), pathogen infection (33-fold), and phytohormone treatments, notably methyl jasmonate (1124-fold), auxin (568-fold), and abscisic acid (400-fold). These findings reveal a dual role of GgUGT72Z in xenobiotic glycosylation and stress tolerance, providing new insights into glycosylation-mediated defense in Glycyrrhiza.

Triple-negative breast cancer (TNBC) is a highly aggressive subtype of breast cancer. This study investigates the therapeutic potential of saikosaponin D (SSD), an active compound from Bupleurum chinense, in targeting the signal transducer and activator of transcription 3 (STAT3)/c-Myc signaling pathway in MDA-MB-231 cells. In silico analysis utilizing AutoDock Vina and HawkDock server predicted SSD's binding affinity with pivotal proteins such as STAT3 and c-Myc, uncovering a complex network of interactions. Molecular dynamics simulation using Schrödinger forecasted the stability of SSD with these target proteins. In vitro studies encompass a range of assays to evaluate the impact of SSD on MDA-MB-231 cells. SSD significantly decreased cell viability (IC₅₀ -7.293 µM) and inhibited cell proliferation as evidenced by colony formation assay. Wound healing assay showed that SSD reduced the migratory potential of MDA-MB-231 cells. SSD induces cell morphological changes, confirmed through DAPI staining, scanning electron microscopy, and phalloidin staining. Live/Dead assay provides evidence that SSD causes decreased viability and increased apoptosis in MDA-MB-231 cells. Gene expression studies revealed that 4 µM SSD significantly impacted apoptotic and necroptotic markers. Finally, Western blotting results revealed that SSD effectively inhibits STAT3 phosphorylation and suppresses c-Myc in a dose-dependent manner. In summary, both in silico and in vitro findings underscore SSD's potential as a therapeutic agent against TNBC, highlighting its ability to modulate the STAT3/c-Myc signaling pathway and offering valuable insights for further clinical development.