Bioscience, Biotechnology, and Biochemistry最新文献

This study introduces a paintbrush assay for delivering liquid reagents to Caenorhabditis elegans, overcoming limitations of glass capillaries with viscous or aggregated solutions. Using sorbitol, avoidance patterns matched between methods, but the brush reduced time at high viscosity. Applied to tannic acid, avoidance increased with concentration, confirming the assay's effectiveness and applicability to diverse reagents.

Analysis of various parts of cocoa by LC-ESI-MS/MS revealed that fermented cocoa bean shells contained high amounts of ceramides, especially a hydroxy phytoceramide (t18:0-h24:0, 466.6 μg/g) present in human skin. Its total ceramide content was higher than that in the skins of peanuts, soybeans, or coffee beans, suggesting that this high content is a unique feature of fermented cocoa bean shells.

In the fission yeast Schizosaccharomyces pombe, 10(R)-acetoxy-8(Z)-octadecenoic acid and 10(R)-hydroxy-8(Z)-octadecenoic acid (collectively termed nitrogen signaling factors, NSFs), function as signaling molecules mediating cell-cell communication in nitrogen catabolite repression. However, it remains unclear whether production of these compounds is conserved across related yeasts. Here, we developed a sensitive liquid chromatography-mass spectrometry-based method for their absolute quantification and applied it to diverse yeast species. Both compounds were detected in Schizosaccharomyces octosporus, Schizosaccharomyces osmophilus, Schizosaccharomyces cryophilus as well as in S. pombe, but not in Schizosaccharomyces japonicus or Saccharomyces cerevisiae. Moreover, natural isolates of S. pombe produced levels similar to or lower than those of the laboratory strain. These findings indicate that the ability to produce NSFs is partially conserved within the Schizosaccharomyces genus and suggest that these molecules are utilized across related species in nature.

Protein arginine methyltransferases (PRMTs) catalyze the transfer of a methyl group. In Caenorhabditis elegans, asymmetric and symmetric dimethylarginines are abolished in prmt-1; prmt-5 mutant, but half of monomethylarginine remains. Using this mutant as a biological resource for monomethylation, we identified stomatin-1, a membrane protein, as being monomethylated at Arg80. These findings may provide evidence to expand PRMT-mediated modification to membrane proteins.

The relationship between obesity-induced leptin resistance and skin function remains unclear. In this study, we examined the effects of leptin signaling on collagen production in mouse skin. Mice were divided into three groups: control diet, high-fat diet, and switching diet (from the high-fat diet to the control diet). We measured the expression of leptin signaling-related genes and type I tropocollagen levels in the skin. In an additional experiment, leptin was administered to leptin-deficient ob/ob mice to examine the direct effect of leptin signaling on type I collagen synthesis in the skin. Type I tropocollagen levels and Ob-Rb gene expression were decreased in the high-fat diet group. These abnormalities were reversed by the switching diet. We also observed that type I tropocollagen levels were decreased in ob/ob mice, but this abnormality was reversed by leptin administration. It is likely that leptin will help to improve obesity-induced skin fragility.

Blueberry stem extract (BSE), which contains phenolic compounds like proanthocyanidins, reduces liver lipid synthesis, boosts anti-adult T-cell leukemia action, protects retinal cells from blue light damage, and prevents lacrimal hyposecretion. However, the anticancer functions and immunomodulatory effects of BSE are not well understood. To assess the anticancer properties of BSE, MCF-7 and MDA-MB-231 breast cancer (BC) cells were treated with various concentrations of BSE. BSE suppressed the growth of BC cells in a manner dependent on both dose and exposure times. Furthermore, it triggered apoptosis by disrupting mitochondrial membrane potential. BSE also inhibited cell motility in BC cells. Notably, it reduced the expression of PD-1, TIGIT, and LAG-3 immune checkpoint proteins in peripheral blood mononuclear cells, which are critical for antitumor immune response. These findings suggest that BSE has promising anticancer and immunomodulatory properties that warrant further investigation in preclinical models.

Euglena gracilis cells grown in the dark accumulate a β-1,3-glucan called paramylon, synthesized from organic carbon sources. Paramylon has potential applications as a raw material for bioplastics and nanofibers. Strain SM-ZK, a streptomycin-bleached mutant of E. gracilis, lacks chloroplasts permanently and accumulates more paramylon than the wild-type strain. However, data are limited on the fermentation characteristics of this mutant strain. This study compares the cultivation characteristics of E. gracilis strains Z (wild-type strain) and SM-ZK under fed-batch cultivation conditions. Strain SM-ZK showed significantly higher productivity in terms of both biomass yield and glucose consumption than strain Z. Moreover, strain SM-ZK cells appeared to be gradually enlarged during fed-batch cultivation compared with strain Z that grows in uniform sizes. These novel findings support the potential use of strain SM-ZK for industrial-scale production of paramylon.

Reactive carbonyl species (RCS), such as acrolein (Acr), are generated through the degradation of lipid peroxides and exert cytotoxic effects. To identify natural RCS scavengers, we examined 80% ethanol extracts from 46 angiosperm species for Acr-trapping activity using an HPLC-based assay. Strong activities were observed in several taxa, including garlic, spinach, avocado, broccoli, and lotus. In garlic, the active metabolite was identified as S-allyl-L-cysteine sulfoxide (alliin), a characteristic Allium amino acid. Alliin and its S-(1E)-propenyl and S-methyl derivatives (isoalliin and methiin, respectively) trapped up to two Acr molecules at the amino group and exhibited higher activities than known scavengers such as carnosine and epigallocatechin gallate. These findings highlight S-alk(en)yl-L-cysteine sulfoxides as potent secondary antioxidants and suggest that structurally diverse RCS scavengers remain to be discovered in plants.

The brown alga Dictyopteris polypodioides produces a variety of sesquiterpene derivatives. However, its potential as an antimelanogenic agent remains unclear. In this study, we investigated the ability of D. polypodioides extract and its constituent compounds to inhibit melanin biosynthesis. Methanolic extracts of D. polypodioides significantly suppressed melanin accumulation in B16 melanoma 4A5 cells. We identified four sesquiterpene hydroquinone derivatives, zonarol (1), yahazunol (2), isozonarol (3), and chromazonarol (6), as active constituents. Structure-activity relationship analyses, including those of semisynthetic analogs, indicated that the hydroquinone moiety is crucial for the antimelanogenesis activity. Chromazonarol (6), which lacks a hydroquinone group, inhibits tyrosinase (monophenolase) in an uncompetitive manner, with 50% inhibitory concentration of 6.2 µm. Quantitative analysis revealed that these sesquiterpene derivatives accounted for approximately 5.6% of the dried algal biomass. D. polypodioides is a promising natural source of bioactive compounds with potential applications in preventing melanogenesis and food browning.

Bionanocapsules (BNCs), hollow nanoparticles derived from the hepatitis B virus (HBV) surface L protein, originated from HB vaccine development and have evolved into a versatile biotechnological platform. Evolving from the first-generation S antigen vaccine, we developed second-generation (M antigen) and third-generation (L antigen) vaccines with enhanced protective efficacy, the latter giving rise to BNCs. BNCs retain the human liver-specific infection machinery of HBV and exhibit stealth, targeting, and endosomal escape abilities as a drug delivery system (DDS). Furthermore, BNCs have been applied to re-targeting via antibody display and as nanoscaffolds for high-sensitivity biosensors, resulting in breakthroughs across DDS, infection-mechanism elucidation, and biosensing technologies.