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Biomedical subjects

Xiaofeng Wang

Publications and source records attributed to Xiaofeng Wang.

5 recordsLinked to original sources

Dual Roles of RAD23b and RAD4 on the Desiccation Tolerance of Germinated Seeds.

Desiccation tolerance (DT) is a survival trait enabling orthodox seeds to withstand extremely low water content. While some protective factors are characterised, it remains mechanistically obscure. Here, based on PEG-induced DT re-establishment in germinated Brassica napus L. seeds, we investigated the dual functions of nucleotide excision repair (NER) components RAD23b and RAD4 in DNA repair and transcriptional regulation of root development. PEG pre-treatment alleviated dehydration-induced DNA damage and activated NER genes, suggesting the involvement of NER in seed DT. Unexpectedly, Arabidopsis atrad23b mutant and BnRAD23b/BnRAD4 over-expressing seeds all exhibited significantly decreased DT after dry back, which evoked a hypothesis that BnRAD23b-BnRAD4 functions beyond NER. Normally, BnRAD4 interacted with BnRAD23b and repressed the expression of root development genes NAC103, EMB1444, RRA1 by directly binding to STRE elements within their promoters. Dehydration stress alleviated this repression, drove transcriptional reprogramming and might redirect the complex to execute DNA repair. Genetic analyses revealed that germinated seeds of atnac103, atemb1444, and atrra1 single mutants all exhibited reduced DT, and double mutants under atrad23b background almost abolished DT. This study suggests that RAD23b and RAD4 may regulate DT re-establishment of germinated seeds through balancing genome integrity and radicle development, with implications for DT study broadly.

Brassica napus L.

Feasibility of Prone Positioning in Patients With Obesity and Acute Respiratory Distress Syndrome.

BACKGROUND: Prone positioning in patients with obesity remains uncommon because of concerns about feasibility, safety, and efficacy. OBJECTIVE: To evaluate the feasibility, safety, and clinical outcomes of manual prone positioning in patients with acute respiratory distress syndrome (ARDS) across different classes of obesity. METHODS: This was a retrospective cohort study involving patients with ARDS who underwent manual prone positioning across 15 hospitals between April 2014 and July 2024. Patients were stratified into 5 groups based on body mass index. Standardized prone positioning protocols were followed across institutions. RESULTS: A total of 1448 patients with ARDS underwent prone positioning. Across all obesity categories, prone positioning was associated with shorter intensive care unit and hospital stays, improved oxygenation, and better clinical outcomes. Notably, patients with class III obesity showed the greatest increase in gas exchange efficiency, with a 37% improvement in ratio of Pao2 to fraction of inspired oxygen, compared with 28% in patients with normal weight (P < .05). Complication rates were low across all groups. CONCLUSIONS: Prone positioning is feasible and safe in patients with ARDS across all obesity classes. Patients with class III obesity showed the greatest improvements in oxygenation. Future prospective studies should further explore the long-term impact of prone positioning in patients with class III obesity to refine clinical guidelines and optimize care.

Humans

Towards efficient perturbation for the noncoding genome.

Deciphering the functionality of the noncoding genome, which includes important cis-regulatory elements (CREs) and transcribed noncoding RNA genes, remains technically challenging. Here, using massively parallel genetic screening, we systematically benchmark the performance of five representative loss-of-function perturbation tools, including single-guide RNA (gRNA) mediated SpCas9 cleavage or CRISPR interference, and paired gRNA (pgRNA) involved dual-SpCas9, Big Papi (paired SpCas9 and SaCas9) or dual-enAsCas12a fragment deletion methods, in decoding the roles of the noncoding genome. For targeting CREs such as enhancers, dual-SpCas9 outperforms other methods with superior efficiency in destroying functional genomic regions. For perturbing noncoding RNA genes, in addition to dual-SpCas9, other RNA-targeting methods such as RNA interference are recommended to discriminate transcript-dependent or -independent roles. A deep learning model, DeepDC, with an associated web server, is built to facilitate optimal dual-SpCas9 pgRNA design for efficiently deleting a genomic fragment. Together, our work provides practical guidance on selecting appropriate loss-of-function tools to resolve the functional complexity of the noncoding genome.

CRISPR-Cas Systems

Seq2Saccharide: Discovering Oligosaccharides and Aminoglycosides Natural Products by Integrating Computational Mass Spectrometry and Genome Mining.

Natural oligosaccharides and aminoglycosides are important sources of new drug candidates, especially in the development of antibiotics. In the past, discovering novel saccharides has been time-consuming and costly. However, the rapid expansion of high-throughput data, including genomic and mass spectrometry data sets, has greatly increased opportunities for natural saccharide discovery. Yet, due to the complex biosynthesis pathways of saccharides, no existing method can predict their structures with high precision. To address this, we introduce Seq2Saccharide, a tool designed to automate saccharide natural product discovery by integrating both genomic and mass spectrometry data. To enhance accuracy, Seq2Saccharide predicts hundreds or thousands of putative structures for each gene cluster. The correct structure is then identified from these predictions using a mass spectral search. Benchmarks against saccharides in the MiBIG database show that Seq2Saccharide outperforms existing methods in predicting the structure of saccharides. Furthermore, mass spectrometry analysis indicates that the variable search module can correct mispredictions from genome mining. By searching genomic and mass spectrometry data of microbial strains, Seq2Saccharide correctly identified the biosynthetic gene cluster for the polysaccharide oligosaccharide trestatin B.

Aminoglycosides

Gut metagenome and plasma metabolome profiles in older adults suggest pyruvate metabolism as a link between sleep quality and frailty.

Poor sleep quality is associated with increased frailty in older adults, but the role of the gut microbiome in this relationship remains unclear. Here, gut metagenome and plasma metabolome were profiled in 1,225 individuals aged 62-96 years. Poor sleep quality was associated with reduced abundances of potential probiotics such as Faecalibacterium prausnitzii and elevated abundances of pathobionts. A gut microbiome sleep quality index (GMSI) was developed to quantify microbial balance related to better sleep quality; higher GMSI scores were inversely associated with frailty and related clinical traits. Pyruvate metabolism emerged as a key microbial pathway linking sleep quality to frailty, with features such as F. prausnitzii abundance and microbial pyridoxal 5'-phosphate biosynthesis implicated in this connection. These findings deepen our understanding of microbiome-metabolome pathways related to sleep quality and frailty in aging and provide a valuable resource for future longitudinal and interventional studies.

Humans