Biomedical subjects

Shanshan Xu

Publications and source records attributed to Shanshan Xu.

3 recordsLinked to original sources

PubMed2026

Dynamic effects of short-term storage temperature and duration on the transcriptome and functional pathways of umbilical cord blood-derived NK cells.

OBJECTIVE: This study aims to elucidate the dynamic impact of different storage conditions (temperature and time) on the function of natural killer (NK) cells derived from umbilical cord blood (UCB) at the transcriptome level, providing a theoretical basis for optimizing the standardized post-collection processing protocol of UCB in clinical settings. METHODS: Four healthy full-term UCB samples were collected and assigned to a fresh control group (0H) and experimental groups stored at 4 °C (4C) or 25 °C (RT) for 24 h (24H) and 72 h (72H). Umbilical cord blood mononuclear cells (CBMCs) were isolated and expanded in vitro to derive NK cells. Using RNA sequencing (RNA-seq) technology, combined with principal component analysis (PCA), screening of differentially expressed genes (DEGs), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses, the effects of storage conditions on the transcriptome of NK cells were comprehensively analyzed. RESULTS: The results indicated that storage time was the primary factor causing transcriptomic differences. Compared to the 0H group, storage for 24 h induced a limited number of Differentially Expressed Genes (DEGs) (only 11 in the 24H-RT group), indicating overall transcriptome stability. In contrast, storage for 72 h triggered profound transcriptomic reprogramming, with DEGs significantly enriched in immune activation-related pathways. Specifically, at the 72-h time point, storage at 4 °C compared to 25 °C prevented the downregulation of key metabolic pathways such as 'response to decreased oxygen levels' and 'regulation of leukocyte cell-cell adhesion'. CONCLUSION: CBMC-derived NK cells can tolerate up to 24 h of ex vivo storage while maintaining transcriptome and core functional stability. However, extending the ex vivo storage period to 72 h leads to significant reprogramming in the expression of immune and metabolism-related genes. Notably, the degree of metabolic suppression under refrigerated conditions at 4 °C was less pronounced than that at 25 °C room temperature storage. This study recommends that the ex vivo storage time of UCB should ideally be limited to within 24 h, with room temperature storage being a viable option. If prolonged storage is necessary, refrigeration at 4 °C is advised.

Humans↗

PubMed2026

Depth-dependent microbial succession and interspecies hydrogen transfer drive pit mud maturation in Chinese strong-flavor baijiu fermentation.

Microbial communities in fermentation pit mud play a key role in determining the quality of Chinese strong-flavor baijiu (CSFB). However, the ecological processes underlying pit mud maturation across spatial and temporal scales remain unclear. In this study, amplicon sequencing and metagenomic analyses were employed to investigate the taxonomic succession, community assembly, and metabolic functions of bacterial and archaeal communities during the transition from fresh pit mud (FPM) to new pit mud (NPM) and old pit mud (OPM). A pronounced depth-dependent succession pattern was observed, with 4 cm representing a critical ecological boundary separating distinct community structures and maturation trajectories. During surface-layer maturation, community assembly shifted from stochastic to deterministic processes, accompanied by homogeneous selection and increasing network complexity. In contrast, stochastic processes remained dominant throughout deep-layer maturation. Metagenomic analyses revealed a functional transition from lactate and acetate production, primarily associated with Lactobacillus in FPM and NPM, to butyrate and caproate production associated with Clostridium and Caproiciproducens in OPM. This functional transition was accompanied by enhanced amino acid metabolism, which was associated with the enrichment of Proteiniphilum and Aminobacterium. Notably, methanogen-mediated interspecies hydrogen transfer (IHT) emerged as a key ecological feature during pit mud maturation. In OPM, IHT networks primarily involving Methanobacterium and Methanosarcina linked methanogenesis with reverse β-oxidation through diverse hydrogen-transfer pathways, reinforcing metabolic interactions underlying caproate production. These findings provide new insights into the ecological mechanisms underlying pit mud maturation and offer a theoretical basis for the directed cultivation of high-quality pit mud in CSFB production.

Hydrogen↗

PubMed2025

Whole genome study and construction of SHERLOCK detection method for endemic strains of Burkholderia pseudomallei in Hainan based on third-generation sequencing.

UNLABELLED: Burkholderia pseudomallei (Bp) is a gram-negative bacterium found in soil and surface water. It is also the pathogen that causes melioidosis disease in humans and animals. This study aimed to obtain the whole genome sequence of the endemic strain of Bp in Hainan, using third-generation sequencing (TGS) technology, and elucidate the genome structure, function, and genetic evolution. Additionally, the study aimed to achieve rapid and specific identification of these endemic strains using specific high-sensitivity enzymatic reporter unlocking (SHERLOCK) detection technology, providing a new strategy for the early diagnosis of melioidosis. Utilizing the PacBio platform for TGS technology, we completed whole genome sequencing of 16 Bp strains from Hainan. High-precision and complete genome sequences were obtained through quality control and genome assembly of the sequencing data. Additionally, we established a nucleic acid detection technology platform based on SHERLOCK, which could be completed from nucleic acid extraction to result reading within 1-2 hours, demonstrating good sensitivity and specificity (both are 100%). The lateral chromatography strip method does not require special equipment and holds promise as an immediate screening method for the early diagnosis of melioidosis. IMPORTANCE: Melioidosis is a highly pathogenic infectious disease caused by a gram-negative bacterium of Burkholderia pseudomallei (Bp). The traditional gold standard for diagnosing melioidosis is still isolation and culture from clinical samples. Although this method has high specificity, it has low sensitivity and is time-consuming, which often leads to misdiagnosis or missed diagnosis of melioidosis, affecting subsequent treatment. In this study, recombinase polymerase amplification technology and clustered regularly interspaced short palindromic repeats/Cas13a technology were combined to establish the Specific High-sensitivity Enzymatic Reporter Unlocking detection technology, which can achieve rapid and accurate identification of Bp, providing a new method for the early diagnosis of melioidosis.

Burkholderia pseudomallei↗