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Biomedical subjects

Xue Liu

Publications and source records attributed to Xue Liu.

8 recordsLinked to original sources

Proteomic Analysis of Biomineralization Proteins in the Shell Plates and Spicules of Chiton Acanthochitona rubrolineata.

Chitons, ancient polyplacophoran mollusks, are ideal models for studying biomineralization evolution due to their conserved morphology since the Cambrian. This study investigates the matrix proteins in shell plates and spicules of Acanthochitona rubrolineata using liquid chromatography-tandem mass spectrometry. By extracting proteins from 30 individuals and using proteomic method, we identified 26 soluble proteins and 22 insoluble proteins in the shell plates and 25 insoluble proteins, and found domains such as von Willebrand factor type A, chitin-binding, ferritin, and cadherin. These domains, prevalent in molluscan biominerals, suggest conserved roles in organic matrix formation. Despite genomic dynamism, the conservation of key domains across species highlights a core biomineralization mechanism. Notably, eight of the shell proteins and eight of the spicule proteins were homologous between A. rubrolineata and chiton Acanthopleura loochooana, indicating functional conservation. Phylogenetic analysis further supported the evolutionary significance of these domains in chitons. The study advances understanding of biomineralization in Polyplacophora, emphasizing the interplay between morphological stasis and molecular evolution.

matrix proteins

Frequent mutations in the BIRC3 gene promote metastatic potential of nasopharyngeal carcinoma cells through the TRAF2-NF-κB pathway.

Nasopharyngeal carcinoma (NPC) is a head and neck cancer characterized by highly locoregionally invasive behavior attributable to the latent infection with Epstein-Barr virus (EBV) and genomic instability. It is well established that EBV-encoded oncogenic molecules actively contribute to the malignant behavior of NPC cells. However, the mechanism by which aberrant genomic alterations enable NPC cells to become aggressive remains largely unknown. In the present study, whole-exome sequencing (WES) revealed that the gene encoding the baculoviral IAP repeat-containing 3 (BIRC3) protein was frequently mutated in circulating tumor cells (CTCs) but not in paired primary tumor cells from patients with metastatic NPC. A minigene assay indicated that the c.637 A > G mutation disrupted normal mRNA splicing, resulting in the partial deletion of Exons 2 and 3 and altered stability of BIRC3 mRNA. In vitro experiments demonstrated that ectopic expression of the BIRC3c.637A>G mutant enhanced NPC cell invasive properties, including proliferation, resistance to apoptosis, migration, and invasion. Furthermore, overexpression of wild-type BIRC3 promoted invasive characteristics in NPC cells through the TRAF2-NF-κB signaling axis. In summary, BIRC3 acts as a regulator of the malignant features of NPC cells. Frequent BIRC3 mutations in CTCs, such as the c.637 A > G mutation, further enhance the metastatic potential of disseminated NPC cells by inducing aberrant alternative splicing. These findings suggest the therapeutic feasibility of targeting the BIRC3/TRAF2/NF-κB axis in the treatment of NPC.

Humans

SARS-CoV-2 3CLpro inhibits the replication of influenza viruses through the cleavage of NP and PA.

The co-circulation of multiple viruses can lead to distinct pathological outcomes, yet how severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection influences other viral infections remains poorly understood, despite its documented high frequency during the pandemic. In this study, we investigated how the proteolytic activity of SARS-CoV-2 3C-like protease (3CLpro) influences the replication of influenza A virus. In silico analysis identified candidate 3CLpro cleavage sites across numerous viral proteins, and biochemical assays confirmed that 3CLpro catalyzes the degradation of influenza virus nucleoprotein (NP) and polymerase acidic protein (PA) in a manner requiring its protease activity. This degradation of NP and PA, which are essential for viral genome packaging and transcription, disrupted the influenza replicative cycle and suppressed viral replication, both upon ectopic 3CLpro expression and during SARS-CoV-2 infection. Our data uncover a direct, enzyme-based mechanism by which SARS-CoV-2 can suppress influenza virus replication during coinfection. We provide a molecular explanation for the sharp, global decline in influenza activity observed during the COVID-19 pandemic and illustrate how enzymatic weapons of one virus can be repurposed to restrain a competing pathogen.

Virus Replication

Gut microbiota dysbiosis and host metabolite-immune crosstalk drives the pathogenesis of neonatal lupus erythematosus: a multi-omics analysis.

BACKGROUND: Neonatal lupus erythematosus (NLE) is a rare autoimmune condition triggered by the transplacental transfer of maternal antibodies. Despite its recognized clinical manifestations, the underlying pathogenesis remains incompletely understood. This study seeks to explore the disruption of the gut microbiota-host metabolism-immune axis in anti-Ro/La-positive neonates, and to assess its potential role in the development of NLE. METHODS: This multicenter, cross-sectional study included 90 neonates, divided into three groups: 30 with neonatal lupus erythematosus (NLE), 30 with positive antibodies but without clinical manifestations (No-NLE), and 30 healthy controls. We performed 16 S rRNA sequencing to analyze gut microbiota composition, untargeted plasma metabolomic profiling, and proteomic analysis to identify alterations associated with the pathogenesis of NLE. RESULTS: We identified significant alterations in the gut microbiota, plasma metabolome, and proteome profiles of anti-Ro/La-positive neonates. NLE infants exhibited marked enrichment of Enterobacteriaceae and depletion of Bifidobacterium and Clostridium butyricum. Metabolomic analysis revealed hyperactivation of β-alanine and purine metabolism, along with impaired α-linolenic acid metabolism and endocannabinoid signaling. Proteomic profiling indicated aberrant protein expression that modulated IFN signaling, particularly within the C-type lectin receptor pathway. Dysregulation of the spleen tyrosine kinase (SYK) and high-affinity immunoglobulin epsilon receptor subunit gamma (FCER1G) decoupling was observed, correlating with elevated IFN-α and NF-κB p65 levels. Integrated correlation analysis revealed significant associations among differential microbial taxa, plasma metabolites, and proteins. Notably, E. coli-associated metabolites and proteins displayed inverse relationships with those associated with C. butyricum. CONCLUSIONS: These findings represent comprehensive evidence of dysregulation along the "gut microbiota-host metabolism-immune" axis in neonatal lupus erythematosus (NLE), providing novel insights into the disease's underlying heterogeneity.

Humans

Multi-omics panorama of glaucoma: Pathogenesis, biomarkers, and novel therapeutic strategies.

Glaucoma is a group of irreversible, blinding eye diseases characterized by progressive loss of retinal ganglion cells, leading to gradual visual field defects that severely impact patients' quality of life. Its complex pathophysiological mechanisms remain incompletely understood, limiting the development of early diagnostic and effective therapeutic strategies. Advances in omics technologies have provided new insights into elucidating the pathophysiology of glaucoma. We summarize specific alterations in genomics, transcriptomics, proteomics, metabolomics, epigenomics, and microbiomics associated with glaucoma. We emphasize the systematic analysis of disease mechanisms, identification of clinically applicable biomarkers, and discovery of novel therapeutic targets through the integration of these data. This approach paves new pathways for glaucoma subtype diagnosis and personalized treatment, while also outlining future research directions and challenges.

Humans

Genome-wide analysis of fitness determinants of Staphylococcus aureus during growth in milk.

Staphylococcus aureus is a major concern in the dairy industry due to its significance as a pathogen causing bovine mastitis as well as a source of food poisoning. The nutrient-rich milk environment supports bacterial growth, but the specific genetic determinants that facilitate S. aureus proliferation and persistence in milk are poorly understood. In this study, we conducted a genome-wide CRISPR interference sequencing (CRISPRi-seq) screen with the laboratory strain S. aureus NCTC8325-4, to identify fitness determinants essential for S. aureus growth and survival in milk. We identified 282 milk-essential genes, including those with key roles in DNA replication, protein synthesis, and metabolism. Comparative analysis with brain heart infusion (BHI) as growth medium, revealed 79 genes with differential fitness, highlighting specific adaptations required for growth in milk. Notably, we found that purine biosynthesis, folate cycle pathways, and metal acquisition were particularly important in this environment. Based on this, we further demonstrate that S. aureus is more sensitive to the folate inhibitors trimethoprim-sulfamethoxazole (TMP-SMX) in milk and identify several genes whose knockdown results in hypersensitivity to TMP-SMX in milk. Additionally, our analysis showed a relatively reduced importance of cell wall components, such as teichoic acids, for S. aureus fitness in milk, which is also reflected in reduced efficiency of antimicrobials targeting teichoic acids. Together, these findings provide new insights into the genetic basis of S. aureus fitness and antibiotic susceptibility in milk, offering directions for novel treatment strategies against bovine mastitis.

Animals

Association analysis between an epigenetic alcohol risk score and blood pressure.

BACKGROUND: Epigenome-wide association studies have identified multiple DNA methylation sites (CpGs) associated with alcohol consumption, an important lifestyle risk factor for cardiovascular diseases. This study aimed to test the hypothesis that an alcohol consumption epigenetic risk score (ERS) is associated with blood pressure (BP) traits. RESULTS: We implemented an ERS based on a previously reported epigenetic signature of 144 alcohol-associated CpGs in meta-analysis of participants of European ancestry. We found a one-unit increment of ERS was associated with eleven drinks of alcohol consumed per day, on average, across several cohorts (p&#x2009;<&#x2009;0.0001). We examined the association of the ERS with systolic blood pressure (SBP), diastolic blood pressure (DBP), and hypertension (HTN) in 3,898 Framingham Heart Study (FHS) participants. Cross-sectional analyses in FHS revealed that a one-unit increment of the ERS was associated with 1.93&#xa0;mm Hg higher SBP (p&#x2009;=&#x2009;4.64E-07), 0.68&#xa0;mm Hg higher DBP (p&#x2009;=&#x2009;0.006), and an odds ratio of 1.78 for HTN (p&#x2009;<&#x2009;2E-16). Meta-analysis of the cross-sectional association of the ERS with BP traits in eight independent external cohorts (n&#x2009;=&#x2009;11,544) showed similar relationships with BP levels, i.e., a one-unit increase in ERS was associated with 0.74&#xa0;mm Hg (p&#x2009;=&#x2009;0.002) higher SBP and 0.50&#xa0;mm Hg (p&#x2009;=&#x2009;0.0006) higher DBP, but not with HTN. Longitudinal analyses in FHS (n&#x2009;=&#x2009;3260) and five independent external cohorts (n&#x2009;=&#x2009;4021) showed that the baseline ERS was not associated with a change in BP over time or with incident HTN. CONCLUSIONS: Our findings demonstrate that the ERS has potential clinical utility in assessing lifestyle factors related to cardiovascular risk, especially when self-reported behavioral data (e.g., alcohol consumption) are unreliable or unavailable.

Humans

Association analysis of mitochondrial DNA heteroplasmic variants: Methods and application.

We rigorously assessed a comprehensive association testing framework for heteroplasmy, employing both simulated and real-world data. This framework employed a variant allele fraction (VAF) threshold and harnessed multiple gene-based tests for robust identification and association testing of heteroplasmy. Our simulation studies demonstrated that gene-based tests maintained an appropriate type I error rate at &#x3b1;&#x202f;=&#x202f;0.001. Notably, when 5&#x202f;% or more heteroplasmic variants within a target region were linked to an outcome, burden-extension tests (including the adaptive burden test, variable threshold burden test, and z-score weighting burden test) outperformed the sequence kernel association test (SKAT) and the original burden test. Applying this framework, we conducted association analyses on whole-blood derived heteroplasmy in 17,507 individuals of African and European ancestries (31&#x202f;% of African Ancestry, mean age of 62, with 58&#x202f;% women) with whole genome sequencing data. We performed both cohort- and ancestry-specific association analyses, followed by meta-analysis on both pooled samples and within each ancestry group. Our results suggest that mtDNA-encoded genes/regions are likely to exhibit varying rates in somatic aging, with the notably strong associations observed between heteroplasmy in the RNR1 and RNR2 genes (p&#x202f;<&#x202f;0.001) and advance aging by the Original Burden test. In contrast, SKAT identified significant associations (p&#x202f;<&#x202f;0.001) between diabetes and the aggregated effects of heteroplasmy in several protein-coding genes. Further research is warranted to validate these findings. In summary, our proposed statistical framework represents a valuable tool for facilitating association testing of heteroplasmy with disease traits in large human populations.

Humans