This study aimed to investigate the inhibitory effect of tubuloside B (Tub B) on amyloid β-protein (Aβ), and analyse the potential mechanism. A model of amyloid fibril was established by incubation of Aβ_1-42 in vitro. Thioflavin-T (ThT), Congo red (CR), 8-anilino-1-naphthene sulfonic acid (ANS) staining and transmission electron microscopy (TEM) were applied to detect the suppression of Tub B on the formation of Aβ_1-42 fibril. Circular dichroism (CD) was used to analyse the regulatory effect of Tub B on the secondary structure of Aβ_1-42. 3-(4,5-Dimethyl-2-thiazole) -2,5-diphenyltetrazolium bromide (MTT) and red blood cell hemolysis experiments were used to investigate the attenuation of Tub B on Aβ_1-42 induced cytotoxicity. 2',7'-Dichlorofluorescin diacetate (DCFH-DA) staining was used to assess the expression of intracellular reactive oxygen species (ROS) induced by Aβ_1-42. And molecular docking experiment was used to explore the interaction between Tub B and Aβ_1-42. The results indicated that Tub B could inhibit Aβ_1-42 fibrillization in a certain extent, which retarded the structural transition of α-helix to β-sheet of Aβ_1-42, hampered the exposure of hydrophobic regions, and attenuated amyloid-induced cytotoxicity and hemolysis. In summary, Tub B can prevent the formation of Aβ_1-42 amyloid fibril, which may be related to its antioxidant activity and hydrogen bonding and hydrophobic interactions with protein molecules. All animal experiments were approved by the Experimental Animal Research Center of Air Force Medical University (No. 20190051).

In view of the few studies on the influence of Armillaria spp. infection on the content of the chemical components in different parts of Polyporus umbellatus sclerotia, this study determined the biomass of P. umbellatus sclerotia and the contents of ergosterol, polyporusterone A, polyporusterone B and polysaccharide in the separated cavity wall of the sclerotia and the uninfected part of the sclerotia in different harvesting years under the conditions of A. gallica and A. mellea infection respectively. According to the difference of content and dynamic changes of the polysaccharide and the steroid substances, the superior Armillaria sp. was screened to obtain the best harvest years of P. umbellatus. Using HPLC and UV-VIS spectrophotometry methods, the contents of ergosterol, polyporusterone A, polyporusterone B and polysaccharide in P. umbellatus sclerotia infected by the two Armillaria spp. in different years were determined. In addition, the differentially expressed genes related to P. umbellatus polysaccharide synthesis were screened according to the transcriptomic data of different parts of P. umbellatus after A. mellea infection. With the increase of years, the biomass of sclerotia infected by different Armillaria spp. had significant differences, and there were significant differences in the four components of sclerotia. The four components of the separated cavity wall of the sclerotia were significantly higher than those of the uninfected part. The best harvest time was the third year after cultivation. Transcriptomic analysis showed that the infection of Armillaria spp. could significantly promote polysaccharide synthesis, which provided a basis for polysaccharide content determination at the molecular level. The study clarified the influence of different Armillaria spp. infection on the accumulation of chemical components of P. umbellatus sclerotia, laying a foundation for exploring the symbiosis mechanism and provided a scientific clue for screening superior Armillaria sp. and guiding the artificial cultivation of P. umbellatus sclerotia.

Salvia miltiorrhiza is a perennial herb of the genus Salvia(Lamiaceae). As one of the earliest medicinal plants to undergo molecular biology research, it has gradually become a model plant for molecular biology of medicinal plants. With the gradual analysis of the genome of S. miltiorrhiza and the biosynthetic pathways of its main active components tanshinone and salvianolic acids, the transcriptional regulation mediated by transcription factors and related regulatory proteins has gradually become a new research focus. Due to the lack of scientific and unified naming of transcription factors and different research indexes in different literature, this paper systematically sorted out the transcription factors in different literature with the genomes of DSS3 from selfing for three generations and bh2-7 from selfing for six generations as reference. In total, 73 transcription factors and related regulatory proteins belonging to 13 gene families were identified. The effects of overexpression or gene silencing experiments on tanshinone and salvianolic acids were also analyzed. This study unified the identified transcription factors, which laid a foundation for further constructing the regulatory networks of secondary metabolites and insect or stress resistance and improving the quality of medicinal materials by using global transcriptional regulation engineering.
Salvia miltiorrhiza/chemistry* ; Plant Proteins/metabolism* ; Gene Expression Regulation, Plant ; Transcription Factors/metabolism* ; Abietanes/metabolism*

In this study, potential quality markers(Q-markers) of Schisandrae Chinensis Fructus for treating bronchial asthma were predicted based on analytic hierarchy process(AHP), entropy weight method(EWM), fingerprint, and network pharmacology. AHPEWM was employed to quantitatively identify the Q-markers of Schisandrae Chinensis Fructus. AHP was used to weight the primary indicators(effectiveness, measurability, and specificity), while EWM was employed to analyze the secondary indicators of each primer indicator. Further, through fingerprint combined with network pharmacology, a ″component-target-pathway″ network was constructed to screen the components of Schisandrae Chinensis Fructus for treating bronchial asthma. It was finally determined that schisandrol A,schisandrin A, and schisandrin B were potential Q-markers of Schisandrae Chinensis Fructus in the treatment of bronchial asthma. This study is the first to comprehensively use AHP-EWM, fingerprint, and network pharmacology to screen the key Q-markers of Schisandrae Chinensis Fructus in the treatment of bronchial asthma. This study provides a scientific basis for improving the quality standard of Schisandrae Chinensis Fructus and lays a foundation for studying its material basis in treating bronchial asthma.
Schisandra/chemistry* ; Asthma/drug therapy* ; Drugs, Chinese Herbal/therapeutic use* ; Network Pharmacology ; Humans ; Entropy ; Lignans/analysis* ; Fruit/chemistry* ; Quality Control ; Cyclooctanes ; Polycyclic Compounds/analysis*

Constructing an efficient and easy-to-operate multigene expression system is currently a crucial part of plant genetic engineering. In this study, a fragment carrying three independent gene expression cassettes and the expression unit of the gene-silencing suppressor protein(RNA silencing suppressor 19 kDa protein, P19) simultaneously was designed and constructed. This fragment was cloned into the commonly used plant expression vector pCAMBIA300, and the plasmid pC1300-TP2-P19 was obtained. Each gene expression cassette consists of different promoters, fusion tags, and terminators. The target gene can be flexibly inserted into the corresponding site through enzymatic digestion and ligation or recombination and fused with different protein tags, which provides great convenience for subsequent detection. The enhanced green fluorescent protein(eGFP) reporter gene was individually constructed into each expression cassette to verify the feasibility of this vector system. The results of tobacco transient expression and laser-confocal microscopy showed that each expression cassette presented independent and normal expression. Meanwhile, the three key enzyme genes in the betanin synthesis pathway, BvCYP76AD, BvDODA1, and DbDOPA5GT, were constructed into the three expression cassettes. The results of tobacco transient expression phenotype, protein immunoblotting(Western blot), and chemical detection of product demonstrated that the three exogenous genes were highly expressed, and the target compound betanin was successfully produced. The above results indicated that the constructed multigene expression system for plants in this study was efficient and reliable and can achieve the co-transformation of multiple plant genes. It can provide a reliable vector platform for the analysis of plant natural product synthesis pathways, functional verification, and plant metabolic engineering.
Nicotiana/metabolism* ; Genetic Vectors/metabolism* ; Gene Expression Regulation, Plant ; Plant Proteins/metabolism* ; Plants, Genetically Modified/metabolism* ; Genetic Engineering/methods* ; Green Fluorescent Proteins/metabolism* ; Gene Expression

(+)-Borneol, the main component of "Natural Borneol" in the Chinese Pharmacopoeia, is a high-end spice and precious medicine. Plant extraction cannot meet the increasing demand for (+)-borneol, while microbial biosynthesis offers a sustainable supply route. However, its production was extremely low compared with other monoterpenes, even with extensively optimizing the mevalonate pathway. We found that the key challenge is the complex and unusual dephosphorylation reaction of bornyl diphosphate (BPP), which suffers the side-reaction and the competition from the cellular dephosphorylation process, especially lipid metabolism, thus limiting (+)-borneol synthesis. Here, we systematically optimized the dephosphorylation process by identifying, characterizing phosphatases, and balancing cellular dephosphorylation metabolism. For the first time, we identified two endogenous phosphatases and seven heterologous phosphatases, which significantly increased (+)-borneol production by up to 152%. By engineering BPP dephosphorylation and optimizing the MVA pathway, the production of (+)-borneol was increased by 33.8-fold, which enabled the production of 753 mg/L under fed-batch fermentation in shake flasks, so far the highest reported in the literature. This study showed that rewiring dephosphorylation metabolism was essential for high-level production of (+)-borneol in Saccharomyces cerevisiae, and balancing cellular dephosphorylation is also helpful for efficient biosynthesis of other terpenoids since all whose biosynthesis involves the dephosphorylation procedure.

Intestinal aging is central to systemic aging, characterized by a progressive decline in intestinal structure and function. The core mechanisms involve dysregulation of epithelial cell renewal and gut microbiota dysbiosis. In addition to previous results in model organisms like Drosophila melanogaster, recent studies have shown that in mammalian models, aging causes increased intestinal permeability and intestinal-derived systemic inflammation, thereby affecting longevity. Therefore, anti-intestinal aging can be an important strategy for reducing frailty and promoting longevity. There are three key gaps remaining in the study of intestinal aging: (1) overemphasis on aging-related diseases rather than the primary aging mechanisms; (2) lack of specific drugs or treatments to prevent or treat intestinal aging; (3) limited aging-specific dysbiosis research. In this review, the basic structures and renewal mechanisms of intestinal epithelium, and mechanisms and potential therapies for intestinal aging are discussed to advance understanding of the causes, consequences, and treatments of age-related intestinal dysfunction.

Gene regulation relies on the precise binding of transcription factors (TFs) at regulatory elements, but simultaneously detecting hundreds of TFs on chromatin is challenging. We developed cFOOT-seq, a cytosine deaminase-based TF footprinting assay, for high-resolution, quantitative genome-wide assessment of TF binding in both open and closed chromatin regions, even with small cell numbers. By utilizing the dsDNA deaminase SsdAtox, cFOOT-seq converts accessible cytosines to uracil while preserving genomic integrity, making it compatible with techniques like ATAC-seq for sensitive and cost-effective detection of TF occupancy at the single-molecule and single-cell level. Our approach enables the delineation of TF footprints, quantification of occupancy, and examination of chromatin influences on TF binding. Notably, cFOOT-seq, combined with FootTrack analysis, enables de novo prediction of TF binding sites and tracking of TF occupancy dynamics. We demonstrate its application in capturing cell type-specific TFs, analyzing TF dynamics during reprogramming, and revealing TF dependencies on chromatin remodelers. Overall, cFOOT-seq represents a robust approach for investigating the genome-wide dynamics of TF occupancy and elucidating the cis-regulatory architecture underlying gene regulation.
Transcription Factors/genetics* ; Humans ; Chromatin/genetics* ; Animals ; Binding Sites ; Mice ; DNA Footprinting/methods*

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