Search bioRxiv⌕ Search

Biology subjects

Huang, A. G.

Publications and source records attributed to Huang, A. G..

2 recordsLinked to original sources
bioRxiv2025

Spatial Transcriptomics Reveals CXCL12+ Fibroblasts as Central Immune Organizers through CXCR4 Signaling in Abdominal Aortic Aneurysm

BACKGROUNDAbdominal aortic aneurysm (AAA) is characterized by sterile inflammation, immune cell infiltration, and stromal remodeling that progressively weaken the aortic wall, leading to life-threatening aortic rupture. The molecular mechanisms and spatial organization of immune-stromal interactions in human tissue are poorly understood, limiting the potential to develop effective pharmacological therapy for AAA. METHODSIn this observational cross-sectional study, formalin-fixed, paraffin-embedded tissues from 11 AAA patients and 12 controls were analyzed by Xenium spatial transcriptomics. Cellular states and localization within tissue architecture were mapped to identify cellular neighborhoods and infer cell-cell communication. RESULTSWe generated a high-resolution spatial transcriptomics atlas of 581,664 cells in 26 clusters. AAAs showed a significant loss of contractile smooth muscle cells, expansion of pro-angiogenic endothelial subsets, and broad infiltration of immune cells. These inflammatory changes were accompanied by expansion of activated, universal, and CXCL12 adventitial fibroblasts. Spatial transcriptomic analysis revealed fibroblast-immune colocalization and adventitial tertiary lymphoid organs. Inferred signaling pathway analysis identified increased interactions between CXCL12 fibroblasts and CXCR4 T and B cells in the adventitia of AAAs. Fibroblasts that expressed CXCL12 had significantly more immune cell neighbors than fibroblasts that did not, suggesting that they serve as stromal hubs for adaptive immune clustering. Genome-wide association analysis linked AAA heritability to fibroblasts, modulated smooth muscle cells, and foamy macrophages. CONCLUSIONOur novel high-resolution spatial transcriptomic atlas of human AAAs revealed coordinated pathogenic reprogramming of stromal and immune cells, defined by smooth muscle cell depletion, fibroblast activation, endothelial remodeling, and disproportionate expansion of immune cells. Through CXCR4 signaling, CXCL12 fibroblasts serve as central organizers of immune niches, suggesting stromal-immune crosstalk as a therapeutic target in AAA. CLINICAL PERSPECTIVESWhat Is New? O_LIWe generated the first subcellular-resolution spatial transcriptomic atlas of human abdominal aortic aneurysm (AAA), with >580,000 cells identified from aortic tissue sections C_LIO_LIWe identified CXCL12+ fibroblasts as central stromal hubs that organize adaptive immune niches through CXCR4-mediated crosstalk with B and T cells C_LIO_LIWe discovered that stromal populations carry the strongest genetic enrichment for AAA risk, notably fibroblast and modulated smooth muscle cell populations C_LI What Are The Clinical Implications? O_LIThese findings position stromal-immune interactions, particularly the CXCL12-CXCR4 axis, as a potential therapeutic target to slow AAA progression C_LIO_LIThe spatial atlas provides a framework for mechanistic studies and drug-discovery efforts, guiding future interventions aimed at modifying the microenvironment that destabilizes the aneurysmal aortic wall C_LI

cell biology↗
bioRxiv2025

Ex Vivo Expanded Regulatory T Cells Inhibit AAA Progression by Limiting CD4+ and CD8+ T Cell Accumulation in Aortic Tissue

BackgroundRegulatory T cells (Tregs) play a crucial role in the pathophysiology of abdominal aortic aneurysms (AAA), a chronic inflammatory condition with few treatment options for patients with early-stage disease. Treg therapy for AAA is potentially beneficial but its specific mechanism requires further investigation for clinical applications. MethodsAfter identifying the critical role of T-cells in AAA using human and mouse AAA single-cell RNA sequencing data, we investigated the influence of Tregs on immune cell infiltration within mouse AAA--specifically CD3+ T cells--using congenic transfer of Thy1.1 allelic donor mice Tregs into AAA-induced wild-type C57BL/6J mice. AAA progression was quantified with ultrasound and image micrometry. Tissues obtained on postoperative days 7-42 were analyzed with flow cytometry, qRT-PCR, Verhoeff-van Gieson staining, hematoxylin-eosin staining, and immunohistochemistry. ResultsCD3+ T cell population was profoundly elevated in the elastase induced AAA mouse model which was further used in the study. The AAA mice that received Treg cell therapy had less elastin degradation and aortic wall enlargement than their control counterparts. Donor Tregs were detected in draining lymph nodes even after five weeks, with characteristic expression of FOXP3 and CD25. Although donor Tregs were not detected in the aortic microenvironment, the pro-inflammatory cell population including CD4 and CD8 cells was reduced, compared to control mice. ConclusionElevated T cell population aggravates inflammation and promotes AAA progression. Treg therapy impedes the recruitment of T cells into AAA tissue by colonizing the draining lymph nodes, thereby mitigating AAA progression. This study deepens our understanding of Treg stability, function, and potential as a promising therapy for early-stage aneurysms.

immunology↗