Biomedical subjects

Yasser Riazalhosseini

Publications and source records attributed to Yasser Riazalhosseini.

3 recordsLinked to original sources

PubMed2026

Airway microbiome diversity, intramucosal bacteria, and spatial immunity in asthmatic adults and controls.

RATIONALE: Asthma is characterized by disruption of the thoracic airway mucosae and loss of microbial diversity. Spatial profiling of the mucosal transcriptome may systematically discover mechanisms for microbial influences on immunity. OBJECTIVES: We investigated relationships between clinical measures, microbial communities, and the host mucosal transcriptome within different strata of bronchial biopsies in subjects with and without asthma. METHODS: We performed bronchoscopy in 65 asthmatic adults and 44 healthy controls, quantifying bacterial operational taxonomic units (OTUs) in bronchial brushings by 16S ribosomal RNA (rRNA) gene amplicon sequences. Biopsy histologic features were scored blind to diagnosis. Following 16S rRNA in situ hybridization of 44 biopsies, bacterial foci were scored in epithelium, basement membrane, and stroma. Global human gene expression was quantified in epithelial and stromal compartments using digital spatial profiling. MEASUREMENTS AND MAIN RESULTS: Clinical asthma was independently predicted by basement membrane abnormalities (BaseMA), endobronchial bacterial diversity, and circulating eosinophil counts, but not by specific OTU abundances. 16S rRNA staining revealed bacteria within epithelium and mucosa of all biopsies. Intramucosal bacteria counts correlated negatively with spatially organized coexpression networks encoding antigen-specific immunity, neutrophil functions, and matrix activation, whereas BaseMA correlated positively with the adaptive immunity module. Eosinophil counts correlated with epithelial bacterial counts and senescence pathways. Clinical asthma was accompanied by upregulation of a regulatory T-cell network. CONCLUSIONS: Asthma and its related phenotypes are accompanied by complex mucosal events that extend beyond eosinophilic pathways. Components of diverse airway microbiota may modify immunity by beneficial interactions within the mucosa.

Humans↗

PubMed2026

Lysyl oxidase inhibition disrupts mitochondrial homeostasis to create vulnerability to ferroptosis in TNBC.

High metabolic heterogeneity and plasticity of triple-negative breast cancer (TNBC) contribute to therapy resistance, necessitating identification of therapeutic vulnerabilities. Here, we identify non-canonical functions of the extracellular matrix (ECM) remodeler, lysyl oxidase (LOX), in regulating glucose metabolism and mitochondrial homeostasis and show that inhibiting LOX generates targetable vulnerability to ferroptosis. Mechanistically, LOX interacts with PARKIN and its upstream kinase PINK1, which we identified as a substrate of LOX. LOX-mediated PINK1 oxidation suppresses PARKIN phosphorylation, stabilizing hypoxia-inducible factor 1-alpha (HIF-1α) and increasing glycolysis. Concomitantly, LOX inhibits PARKIN-mediated mitophagy and maintains mitochondria-ER contacts through VDAC1 stabilization, while the LOX-HSP90 complex promotes mitochondrial Ca2+ transport and ATP production. Inhibiting LOX suppresses glycolysis, disrupts mitochondrial dynamics, reduces OXPHOS and GPX4/FSP1, and induces compensatory DHODH activity. Our "one-two punch" approach combining LOX inhibition with clinical DHODH inhibitor suppresses tumor growth in vivo in chemo-free setting. Notably, LOX protein correlates with HIF-1α/GLUT1/GPX4 in TNBC patient tumors, supporting its clinical relevance.

Ferroptosis↗

PubMed2026

Distinct immune landscapes characterize highly versus minimally invasive brain metastases.

Brain metastases (BrMs) occur in approximately 30% of cancer patients, causing nearly one-fifth of cancer deaths. While immune checkpoint inhibitors (ICIs) benefit some BrM patients, responses remain highly variable. This variability partly reflects distinct histopathological growth patterns that include minimally invasive (MI) and highly invasive (HI) brain BrMs. Here we show that MI BrMs exhibit robust immune infiltration, whereas HI lesions are immunosuppressed. However, histological differentiation between MI and HI can be challenging because of subjective margin assessment. Here, using highly multiplexed spatial proteomics on 119 tumor sections from 46 patients with BrMs, we identify CHI3L1 as a key mediator of the immunosuppressive microenvironment in HI BrMs. In preclinical models, genetic deletion of CHI3L1 converts immune-cold metastases into lymphocyte-rich, ICI-responsive lesions infiltrated by granzyme B+ CD8+ T cells. In BrM patients treated with ICI, immunohistochemical quantification of CHI3L1 expression was a stronger predictor of ICI response than traditional MI/HI classification. Thus, CHI3L1 represents a promising biomarker and therapeutic target for BrMs.

Humans↗