Bioscience, Biotechnology, and Biochemistry最新文献

We take a wide variety of antioxidants, including polyphenols, daily from our diet. They are generally considered to be beneficial for our health. However, the intrinsic function of antioxidants in biological systems remain unknown. On the other hand, antioxidants in general are sensitive to oxidation, generating their oxidized intermediates. Intriguingly, these intermediates are highly reactive to proteins. Although the specific cellular targets and response mechanism remain unclear, protein modification by oxidized antioxidants may represent the intrinsic "moonlight" function of antioxidants by taking on a secondary role beyond their traditional activity. This minireview summarizes recent findings on antioxidants, with a particular focus on the interactions of antioxidant-modified proteins with histones.

Sex differences exist in the commensal microbiota that impact on multiple physiological processes in the host. Here, we examined the mechanism by which the sex differences are formed. In addition to the epithelial ductal cell, the acinar cell mass in the submandibular gland was associated with androgen-androgen receptor (AR) signaling. Sex differences in the formation of submandibular mucin 10 (MUC10) were identified using SDS-PAGE. Neuraminidase treatment, which hydrolyzes terminal sialic acid, influenced the mobility shift of MUC10. Androgen-AR signaling negatively regulated ST3 β-galactoside α-2,3-sialyltransferase 1 (St3gal1) and St3gal4 in the submandibular gland. There was a trend and significant sex differences in α-diversity (Shannon, P = .09) and β-diversity (unweighted UniFrac) in oral microbiota composition, respectively. Some female-preferring bacteria including Akkermansia muciniphila can assimilate mucin by degrading terminal sialic acids. Our results indicate that androgen-AR signaling suppresses ST3GAL1 and ST3GAL4, which can influence sex differences in commensal microbiota composition.

Carnosic acid is a naturally occurring, plant-derived polyphenolic abietane diterpene with antitumor properties. However, its underlying mechanisms are still unclear. Therefore, we investigated the effects of carnosic acid on lung metastasis in a murine melanoma model. C57BL/6 mice were intravenously injected with B16-BL6 cells, followed by carnosic acid treatment. Lung weights were recorded, and tumor cell colonies were counted at the end of the experiment. Integrin expression was evaluated using flow cytometry and cell adhesion assays. Lung weights were significantly lower in the carnosic acid group than in the control group, indicating the suppression of metastasis. Carnosic acid suppressed α4 integrin expression in B16-BL6 cells and inhibited α4 and α9 integrin-dependent cell adhesion. Thus, our data suggest that carnosic acid prevents lung metastasis, possibly by suppressing integrin expression. Our findings support the clinical application of carnosic acid as a potential natural antitumor agent, offering a complementary approach to conventional therapies.

In this study, we developed a hydrostatic pressurizing chamber capable of applying hydrostatic pressure to osteocytic spheroids derived from mouse osteoblastic MC3T3-E1 cells. Our results demonstrate that a 4-h exposure to 200 kPa of hydrostatic pressure did not alter the apparent morphology of the spheroids. However, gene expression analysis revealed a significant up-regulation of Sost, a marker of late-stage osteocyte differentiation.

The results of research on food functionality in Japan have been passed on to society in the form of Foods for Specified Health Uses and Foods with Functional Claims. However, it is also true that there are people who do not experience any health benefits even when they consume these foods. To clarify the factors that cause such individual differences in the health benefits of food, research into the following points is important: (1) Elucidation of the molecular mechanisms behind why food factors exert their functionality. (2) Research into the functional interactions between food factors that exert their functionality in multi-component systems. (3) Research into the functionality of food factors that have not been the subject of research until now. We will introduce the results of our research in these areas. We will also discuss our expectations for the application of food functionality research to pharmaceutical development as an extension of this research.

A new xenicane diterpene named 4α-acetoxyisodictyohemiacetal (1) was isolated from the brown alga Dictyota coriacea, along with 11 known diterpenoids. The structure of 1 was established by spectroscopic analyses, and its absolute configuration was determined by comparing the experimental and theoretical electronic circular dichroism spectra. Two dictyodiacetal diastereomers (5 and 6) were isolated, and the full NMR assignments were performed. The anti-inflammatory activities of the isolated compounds were evaluated using the lipopolysaccharide-stimulated mouse macrophage cell line, RAW264. The hemiacetal-containing xenicanes and dictyol-type diterpene inhibited not only the production of nitric oxide but also the expression of inducible nitric oxide synthase, interleukin-6, and cyclooxygenase-2 mRNA in RAW264 cells. This study demonstrated that diterpenes from D. coriacea may be useful as natural anti-inflammatory agents.

Nano-sized vesicles are ubiquitous in vegetables, fruits, and other edible plants. We have successfully prepared nanovesicles (NVs) from over 150 edible plants. These results suggest that the daily intake of NVs from various foods and their roles in food function are promising novel approaches for explaining the health-promoting properties of edible plants. These vesicles contain RNAs, including miRNAs, similar to extracellular NVs, which play pivotal roles in cell-cell communication. Intriguingly, NVs also contain phytochemicals such as polyphenols and carotenoids that are specific to each edible plant. In conclusion, these dietary NVs have the potential to serve as functional packages to deliver RNAs or phytochemicals to target cells across species from plants to humans.

This study compared the antihypertensive effects of avenanthramides A, B, and C, with a focus on their antioxidant and anti-inflammatory properties. Treatment with avenanthramides A, B, and C (50 μm) significantly enhanced cell viability and nitric oxide production in H2O2-induced endothelial dysfunction in EA.hy926 cells. Avenanthramides notably increased the levels of antioxidant enzymes and glutathione while reducing malondialdehyde and reactive oxygen species. Moreover, avenanthramides promoted the Nrf2 translocation to nucleus, enhancing the expression of antioxidant enzymes. Furthermore, avenanthramides inhibited the protein levels of iNOS and COX-2, as well as the phosphorylation of IkBα and translocation of p65, thereby mitigating endothelial inflammation. Molecular docking analysis revealed that avenanthramide A exhibited the strongest binding affinity for HO-1 and iNOS, which was correlated with its superior biological activity. Overall, by upregulating Nrf2/HO-1 pathways and downregulating NF-kB pathways, avenanthramides show potential as therapeutic agents for the treatment of endothelial dysfunction.

Koji made using Aspergillus oryzae shows potential for application as a cheese adjunct; however, flavor defects resulting from volatile free fatty acid (FFA) accumulation should be avoided. Hence, a modified glucose-containing whey solid medium was used to culture A. oryzae AHU 7139, and the triacylglycerol (TG) lipase activity and lipase gene (tglA and mdlB) expression were compared with those of a culture using a conventional whey solid medium. The results showed that TG lipase activity and the expression of both lipase genes were reduced in the modified medium. Moreover, the expression level of farA, a positive transcription factor of the lipase genes, was also reduced. The cheese adjunct prepared by culturing the AHU 7139 strain in the modified medium lowered the FFA content in the cheese products, resulting in comparable FFA levels with those in the adjunct-free cheese. Thus, adding glucose is recommended to prepare the koji adjunct for cheesemaking.

Sphingolipids (SLs), found in all animals, plants, and fungi and in certain prokaryotic organisms, exhibit essential physiological functions that cannot be replicated by other lipids. Although SLs and their related biomolecules behave as lipid mediators, skin barrier systems, and epitopes, their detailed biological functions have not yet been revealed, unlike those of proteins and nucleic acids, because the biosynthesis of SLs is not governed by the central dogma. Recently, SLs have been widely studied in relation to diseases such as obesity, dementia, and neuron agenesis and have attracted attention as molecules related to unmet medical needs. This review presents the recent applications of the SL chemical biology in unmet medical needs.