Bioscience, Biotechnology, and Biochemistry最新文献

Thrombopoietin (TPO) is essential for treating thrombocytopenia, but its clinical use is limited by immunogenicity and short half-life. TMP, a TPO mimetic peptide, addresses these issues but requires fusion with carriers to improve pharmacokinetics. This study developed ELP-TMP fusion proteins (ELP120-2TMP and 2TMP-ELP120) to extend half-life and enhance activity via elastin-like polypeptide (ELP). Results showed EC50 values of 5.81 n m for ELP120-2TMP and 10.88 n m for 2TMP-ELP120, compared to 2.65 n m for recombinant human TPO (rhTPO). At a dose of 600 nmol/kg, ELP120-2TMP resulted in peak platelet counts in mice on day 20, exhibiting a half-life of 22.9 h. Conversely, 2TMP-ELP120 achieved peak platelet counts on day 12, with a half-life of 25.4 h. The half-lives of both fusion proteins were significantly longer than that reported 2TMP alone (1 h). Area under the curve indicated superior platelet stimulation over rhTPO (P < 0.01).

We developed a simple and effective method for distinguishing mature spores (MSs) of Bacillus subtilis 168 from mixed cell population using Auramine O (AuO) staining combined with flow cytometry (FCM) analysis. AuO preferentially stains MSs, enabling fluorescence-based discrimination. To optimize the method, B. subtilis 168 was stained with AuO and heated at different temperatures (25, 40, 55, or 70 °C) before FCM analysis. Among the tested conditions, heating for 30 min at 55 °C yielded the most distinct separation between MSs and other cell types based on fluorescence intensity. This approach combines the high-throughput capability of FCM with temperature-enhanced fluorescent staining to achieve efficient and accurate spore identification. This method is simple, rapid, and scalable, with potential applications in food safety testing and probiotic product manufacturing, where fast and reliable bacterial enumeration is essential.

Cells must recycle stalled ribosomes while preventing the accumulation of aberrant nascent chains. In bacteria, this is achieved by overlapping pathways with distinct substrates: ribosome-rescue systems act mainly on non-stop mRNAs, whereas ribosome-associated quality control (RQC) targets mid-ORF arrests. Work in Gram-positive bacteria defined an RQC mechanism that appends C-terminal degrons to stalled peptides, yet the full set of bacterial substrates and splitting factors remains unresolved, and enteric bacteria notably lack a canonical RQC elongation factor. This review traces the field from the discovery of tmRNA (also known as 10Sa RNA or SsrA RNA) through alternative rescue pathways to the current bacterial RQC framework. I summarize mechanisms across three layers-processing of 50S-peptidyl-tRNA, collision sensing and splitting, and downstream proteolysis-and compare species-level strategies and conservation patterns. I highlight how rescue and quality control intersect during phage infection, and outline key mechanistic uncertainties and experiments needed to resolve them.

We prepared nanovesicles (NVs) derived from broccoli using ultracentrifugation and evaluated their anti-inflammatory properties. Two distinct NV populations were isolated as precipitates from broccoli homogenates following centrifugation at 20 000 × g and 200 000 × g. These NVs contained RNAs, proteins, isothiocyanates, and chlorophylls. Dynamic light scattering analysis confirmed their nanoscale size. The NVs were internalized by RAW264 cells and significantly inhibited nitric oxide production and NF-κB pathway activation under lipopolysaccharide (LPS) stimulation. Comprehensive analysis of inflammatory cytokine expression revealed strong suppression of interleukin-6 (IL-6) by both NV types, which was further validated by ELISA. Additionally, IL-1β and tumor necrosis factor-α production were also reduced. Notably, the anti-inflammatory effects were partially attributed to small RNAs (<200 nt) present within the NVs. Collectively, these findings suggest that broccoli-derived NVs possess potent anti-inflammatory activity.

Ferritin, a protein ubiquitously found in living organisms, is well known for its major role in iron homeostasis. However, recent studies in invertebrates have revealed that it possesses diverse physiological functions beyond iron homeostasis. Especially in mollusks, ferritin has been suggested to be involved in functions such as restricting iron availability to pathogens during immune responses, mediating iron transport to specific tissues via hemolymph, and contributing to the formation of mineralized tissues, such as shells and radulae. Furthermore, it has been demonstrated that mollusks possess not only the cytoplasmic ferritin found in vertebrates, but also a secretory ferritin, which contains a signal peptide. This review provides a comprehensive overview of molluscan ferritin, summarizing the broad aspects of its molecular structure and physiological functions.

Zinc (Zn), Copper (Cu), and Manganese (Mn) are micronutrients that are essential for biological functions. They act as cofactors for numerous proteins and serve as signaling molecules. Although recent studies have significantly advanced our understanding of the individual roles of these metals, their homeostatic interactions remain largely unclear, except for a few well-documented cases, most notably the well-known competition between Zn and Cu for intestinal absorption. Moreover, recent research in vertebrates has suggested that Mn metabolism is closely linked to Zn metabolism in various cellular processes. Investigating the regulatory mechanisms governing homeostasis of essential trace metals is crucial for elucidating their functions in cellular systems. In this review, we provide a brief overview of the recent advances in understanding the competition between Cu, Mn, and Zn, with a particular focus on the interaction of Zn with the other two metals.

Zinc and iron are essential trace elements indispensable for life in all organisms. However, even when these metals are sufficiently supplied to cells, the disruption of their proper distribution among intracellular organelles can lead to various diseases. ZIP13, a member of the Zrt-, Irt-like protein (ZIP) transporters that is localized to the endoplasmic reticulum (ER) and Golgi apparatus, was originally identified as an intracellular zinc transporter, but was recently shown to also transport iron ions. The dysfunction of ZIP13 disrupts metal distribution in the ER and Golgi apparatus, thereby impairing the homeostasis and function of various tissues. In this review, we summarize current understanding of ZIP13 biology, highlight its dual roles in zinc and iron transport, and discuss future perspectives on how ZIP13 research may provide new insights into the mechanisms underlying diseases associated with dysregulated intracellular metal homeostasis.

This mini-review highlights the emerging agricultural applications of iron oxides, the primary form of iron and one of the most abundant elements on Earth. Rice yield is strongly influenced by soil nitrogen fertility, which is supported by biological nitrogen fixation. Using soil metatranscriptomic analysis and isolation-cultivation experiments, we recently discovered iron-reducing Deltaproteobacteria as the predominant but previously overlooked drivers of nitrogen fixation in paddy soil. As these bacteria utilize Fe3+ as an electron acceptor during anaerobic respiration, we hypothesized that amending soils with Fe3+-rich iron oxides would enhance their nitrogen-fixing activity. Laboratory and field experiments confirmed that applying iron oxides with low crystallinity significantly stimulated the diazotrophic activity of iron-reducing bacteria, enabling reduced nitrogen fertilizer input in rice cultivation, with a reduced nitrogen burden to the environment. Recognition of iron-reducing diazotrophs has opened a new research frontier: using metals, particularly crystalline forms of iron oxides, in sustainable agricultural systems.

Hyperglycemia activates the polyol pathway, producing fructose, which promotes glycation and denatures α-crystallin, ultimately leading to diabetic cataracts. This study compared the antiglycation effects of SMR and SBN, using a fructose-induced human αA-crystallin glycation model. Through fluorescence analysis, SDS-PAGE, and Western blotting methods, we found that glycation caused αA-crystallin to form fluorescent advanced glycation end products (AGEs), cross-linking AGEs, and Nε-carboxymethyllysine (CML). Results show that SMR (> 20 μg/mL) and SBN (> 100 μg/mL) effectively inhibited cross-linking AGEs and CML formation. At concentrations above 4 μg/mL, both significantly reduced fluorescent AGEs, with SMR showing 91.0 ± 0.8% inhibition and SBN 81.1 ± 1.7% at 100 μg/mL. SMR also outperformed aminoguanidine hydrochloride in reducing carbonyl content at 500 μg/mL. Therefore, SMR exhibited stronger antiglycation and antioxidation properties than SBN, showing potential as a natural health product to prevent diabetic cataract formation.