Biology subjects

XIAO, L.

Publications and source records attributed to XIAO, L..

4 recordsLinked to original sources

bioRxiv2026

Isolation, extraction, and physicochemical characterization of exosome-like nanovesicles from ginseng adventitious roots in tissue culture

This study aimed to establish a method for isolating exosome-like nanovesicles from ginseng adventitious roots and their culture supernatant, to investigate the effects of methyl jasmonate (MeJA) induction on vesicle yield and composition, and to provide experimental evidence for the scalable production of ginseng-derived exosome-like nanovesicles. Exosome-like nanovesicles were isolated from ginseng adventitious roots and culture supernatant using low-speed centrifugation combined with stirred-cell ultrafiltration. Physicochemical characterization was performed using transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), Zeta potential analysis, and Q-ToF LC-MS lipidomics. Ginseng adventitious roots were treated with 200 M MeJA to evaluate changes in vesicle particle concentration, total protein, total saponins, and miRNA expression before and after induction. Paraffin section fluorescence staining was used to observe the distribution of vesicle-related signals in adventitious root tissues. Exosome-like nanovesicles with typical bilayer membrane structures were isolated from both ginseng adventitious roots and culture supernatant.The particle size ranged from 77.333 to 171.733 nm, and the particle concentration ranged from 2.1E+8 to 7.6E+10 /mL. The vesicles contained lipid components including glycerides, phospholipids, and sphingolipids. Induction with 200 M MeJA increased vesicle particle concentration and total protein content, significantly upregulated the total saponin level in vesicles derived from adventitious roots, and altered the miRNA expression pattern of the vesicles. Tissue section fluorescence observation showed overlap between vacuolar markers and membrane vesicle dye signals. Low-speed centrifugation combined with ultrafiltration can effectively prepare ginseng-derived exosome-like nanovesicles. MeJA induction can regulate vesicle yield and active components, providing foundational data for the scalable process development of such vesicles.

plant biology↗

bioRxiv2024

Discovery and Engineering of a New BvCas12a Nuclease for Mammalian Genome Editing and Nucleic Acid Detection

Cas12a is an RNA-guided endonuclease that has emerged as a powerful gene-editing tool. We have identified a novel Cas protein, BvCas12a, from Butyricimonas virosa with a 5-TYTN protospacer adjacent motif (PAM). BvCas12a exhibits double-stranded DNA cleavage activity in vitro and genome editing activity in eukaryotic cells. Though the editing efficiency of BvCas12a is marginally lower than that of AsCas12a, the editing specificity of BvCas12a in eukaryotic cells is comparable or superior to that of AsCas12a. Moreover, BvCas12a exhibits substantial collateral activity and can detect HPV DNA effectively and accurately in conjunction with isothermal amplification, highlighting its potential in nucleic acid diagnostics. Furthermore, we have engineered BvCas12a to create two variants, BvCas12a-R (N549R, T606P) and BvCas12a-RVR (N549R, K555V, C559R, T606P). These variants recognize expanded 5-YYN and 5-YN PAM in vitro, respectively. Additionally, they exhibit higher editing activity than wild-type BvCas12a and recognize 5-YYN PAM in vivo at all sites detected. In conclusion, we have identified a novel BvCas12a protein with high specificity and engineered two variants with broader PAM compatibility and improved genome editing efficiency. These findings offer a potent gene editing tool for application in scientific research, gene therapy, and nucleic acid diagnostics.

genomics↗

bioRxiv2023

Rapid and prolonged response of oligodendrocyte lineage cells in standard acute cuprizone demyelination model revealed by in situ hybridization

Dietary administration of a copper chelator, cuprizone (CPZ), has long been reported to induce intense and reproducible demyelination of several brain structures such as the corpus callosum (CC) in mice, followed by spontaneous remyelination after drug withdrawal. Despite the widespread use of CPZ as an animal model for demyelinating diseases such as multiple sclerosis (MS), the mechanism by which it induces demyelination and then allows robust remyelination is still unclear. An intensive mapping of the oligodendrocyte (OL) lineage cell dynamics during the de-and remyelination course would be of particular importance for a deeper understanding of this model. Here, using a panel of OL lineage cell markers as in situ hybridization (ISH) probes, including Pdgfra, Plp, Mbp, Mog, Enpp6, combined with immunofluorescence staining of CC1, SOX10, we provide a detailed dynamic profile of OL lineage cells during the entire course of the model from 3.5 days, 1, 2, 3, 4,5 weeks of CPZ treatment, i.e. the demyelination period, as well as after 1, 2, 3, 4 weeks of recovery (drug withdrawal) from 5 weeks of CPZ treatment, i.e. the remyelination period. The result showed an unexpected early death of mature OLs and response of OL progenitor cells (OPCs) in vivo upon CPZ challenge, and a prolonged upregulation of myelin-forming OLs compared to the intact control even 4 weeks after CPZ withdrawal. These data may point to the need to optimize the timing windows for the introduction of pro-remyelination therapies in demyelinating diseases such as MS, and may serve as a basic reference system for future studies of the effects of any intervention on demyelination and remyelination using the CPZ model.

neuroscience↗

bioRxiv2020

Butyribacter intestini gen. nov., sp. nov., a butyric acid-producing bacterium of the family Lachnospiraceae isolated from the human faeces, and reclassification of Acetivibrio ethanolgignens as Acetanaerobacter ethanolgignens gen. nov., comb. nov.

A novel, non-motile, Gram-stain-positive, non-spore-forming, obligate anaerobic bacterium, designated strain TF01-11T, was isolated from human faeces. The isolate was characterized by phylogenetic and phenotypic properties, as well as by determination of its whole genome sequence. The growth temperature and pH ranges were 30-42 {degrees}C and 6.0-8.5, respectively. The end products of glucose fermentation were butyric acid and a small amount of acetic acid. The genome was estimated to be 3.61Mbp with G+C content of 36.79 mol%. Genes related to biosynthesis of diaminopimelic acid, polar lipids, polyamines, teichoic and lipoteichoic acids were present. The predominant fatty acids were C16:0 (37.9 %), C14:0 (16.4 %), C13:0 OH/iso-C15:1 H (11.1 %) and C18:1{omega} 9c (10.6 %). Phylogenetic analyses based on 16S rRNA gene sequences, the isolate was a member of family Lachnospiraceae, with the highest sequence similarity to the type strain of Roseburia intestinalis DSM 14610T at 92.18 % followed by Acetivibrio ethanolgignens ATCC 33324T at 91.99 %. The average nucleotide identity (ANI) calculated for the genomes between strain TF01-11T and these closest relatives were 70.5 % and 68.1 %. Based on results of phenotypic characteristics and genotypic properties presented in this study, strain TF01-11T represent a novel species in a new genus, for which the name Butyribacter intestini gen. nov., sp. nov. is proposed. The type strain of the type species is TF01-11T (CGMCC 1.5203T = CGMCC 10984T = DSM 105140T). In addition, Acetivibrio ethanolgignens is proposed to be reclassified as Acetanaerobacter ethanolgignens gen. nov., comb. nov.

microbiology↗