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Biomedical subjects

Wenjun Zhang

Publications and source records attributed to Wenjun Zhang.

3 recordsLinked to original sources

Integrated Pan-Cancer, Single-Cell, and Spatial Transcriptomic Analyses Identify ZDHHC12 as a Biomarker Associated with Macrophage Infiltration and the Immune Landscape in Glioma.

BACKGROUND: The tumor immune microenvironment (TME) critically influences cancer progression and therapeutic response. However, the pan-cancer expression landscape, prognostic relevance, and spatial distribution of ZDHHC12 remain incompletely characterized. This study investigated the prognostic value of ZDHHC12 and its associations with immune microenvironmental features and drug sensitivity. METHODS: Data from The Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression (GTEx) datasets were used to evaluate ZDHHC12 expression and prognosis across cancer types. Immune infiltration analyses, single-cell RNA sequencing, and spatial transcriptomics were integrated to characterize the associations of ZDHHC12 with the cancer immunity cycle and the spatial architecture of glioma. Drug sensitivity and immunotherapy-related metrics were assessed using pharmacogenomic databases and computational prediction models. RESULTS: ZDHHC12 was aberrantly expressed across multiple tumors and was associated with patient prognosis. Its expression was broadly correlated with immune cell recruitment- and activation-related signatures. In glioma, single-cell and spatial transcriptomic analyses showed enrichment of ZDHHC12 in monocyte/macrophage populations and spatial co-localization with BAK1, CD68, and CD163. ZDHHC12 expression was also associated with predicted drug sensitivity and immunotherapy-related metrics. CONCLUSION: ZDHHC12 may serve as a candidate pan-cancer prognostic biomarker. In glioma, its expression is associated with macrophage-enriched and immunosuppressive microenvironmental features. Functional studies are required to establish causality and determine its therapeutic relevance.

GBM

Discovery of Isonitrile Lipopeptide Chalkophores from Pathogenic Mycobacteria.

The virulence-associated isonitrile lipopeptide (INLP) biosynthetic gene cluster is conserved across Mycobacterium tuberculosis and many nontuberculous mycobacteria (NTM) pathogens, yet the corresponding mycobacterial metabolites have not been fully characterized, and their biological functions are still debated. Here, we report a precursor neutral loss chromatography based mass spectrometry strategy that enables the targeted discovery of INLPs from Mycobacterium fortuitum, a fast-growing NTM pathogen. By monitoring a characteristic neutral loss of 27.1 Da corresponding to hydrogen cyanide, we identified a family of INLPs directly from bacterial culture extracts. Structural elucidation of a representative compound using NMR and high-resolution MS revealed a distinctive terminal methylated carboxyl group, contrasting with previously reported INLPs bearing linear alcohol, acetal, or cyclic motifs. Bioinformatic analysis and in vitro enzymatic assays identified a methyltransferase encoded within the INLP BGC responsible for methyl ester formation. Furthermore, metal-binding assays demonstrated selective chelation of Cu(I) and Cu(II) by the isolated INLP, but no detectable interaction with Zn(II), suggesting a role in copper homeostasis. These findings represent the first full structural characterization of an INLP from pathogenic mycobacteria, expand our understanding of the enzymes involved in INLP modification, and unequivocally support the copper-binding activity of INLPs from these pathogens.

Lipopeptides

Engineered probiotic overcomes pathogen defences using signal interference and antibiotic production to treat infection in mice.

Probiotic supplements are suggested to promote human health by preventing pathogen colonization. However, the mechanistic bases for their efficacy in vivo are largely uncharacterized. Here using metabolomics and bacterial genetics, we show that the human oral probiotic Streptococcus salivarius K12 (SAL) produces salivabactin, an antibiotic that effectively inhibits pathogenic Streptococcus pyogenes (GAS) in vitro and in mice. However, prophylactic dosing with SAL enhanced GAS colonization in mice and ex vivo in human saliva. We showed that, on co-colonization, GAS responds to a SAL intercellular peptide signal that controls SAL salivabactin production. GAS produces a secreted protease, SpeB, that targets SAL-derived salivaricins and enhances GAS survival. Using this knowledge, we re-engineered probiotic SAL to prevent signal eavesdropping by GAS and potentiate SAL antimicrobials. This engineered probiotic demonstrated superior efficacy in preventing GAS colonization in vivo. Our findings show that knowledge of interspecies interactions can identify antibiotic- and probiotic-based strategies to combat infection.

Animals