Biology subjects

Bashore, A. C.

Publications and source records attributed to Bashore, A. C..

7 recordsLinked to original sources

bioRxiv2026

Associations Between Plasma Lipoprotein(a) Levels and Circulating Monocyte Subsets Differ across Populations

BackgroundLipoprotein(a) [Lp(a)] is a causal risk factor for cardiovascular disease (CVD), with plasma concentrations higher in Black individuals than in White individuals. Published findings support a model in which high Lp(a), in part through oxidized phospholipid (oxPL)-mediated signaling, promotes a pro-inflammatory monocyte phenotype that may contribute to arterial wall inflammation and the development of CVD. Here, we examined the relationship between Lp(a) concentrations and isoform size and the distribution of circulating monocyte populations in Black and White individuals using single-cell RNA sequencing (scRNA-seq) data. MethodsUsing standardized assays, we measured plasma Lp(a) levels, isoform size, inflammatory markers, and oxidized phospholipids in stored plasma samples from our previously published cohort of 128 participants. After excluding smokers and individuals with type II diabetes, a total of 34 participants (20 Black participants, 14 White participants) were included in analyses. Participants were further stratified by plasma Lp(a) levels into normal Lp(a) [median 12.6 nmol/L, with 15 individuals (8 Black participants) and high Lp(a) (median 159 nmol/L, with 19 individuals (12 Black partcipants)]. Multivariable linear regression was used to assess the association between plasma Lp(a) levels, Lp(a)-oxPL, and the proportion of monocyte subsets. Across all participants, scRNA-seq data identified six classical monocyte subsets, one non-classical monocyte subset, one MHCIIhi monocyte subset, and one interferon (IFN)-responsive monocyte subset. ResultsThe distribution of monocyte subsets was similar in individuals with normal versus high Lp(a) levels. Despite the small study cohort, self resported race modified the assocation between plasma Lp(a) levels and the proportion of non-classical monocytes (P = 0.032), which was inversely associated in White participants (P = 0.028), but not in Black partcipatns (P = 0.470). OxPL bound to APO(a) showed a positive correlation with plasma Lp(a) levels (R2 = 0.84; P = 3.3x10-14), and non-classical monocytes (PWhites = 0.027; PBlacks = 0.275; PInteraction = 0.014). Race also modified the association between plasma Lp(a) levels and the proportion of classical 2 monocytes (P = 0.027). ConclusionsThese results underscore the importance of self reported race when analysing studies on Lp(a), monocytes and, cardiovascular related monocyte immune functions.

immunology↗

bioRxiv2025

Integrative Omics Identifies Candidate Plasma Biomarkers and Cellular Targets Associated with Thoracic Aortic Aneurysm

ObjectivesTo define the cellular landscape of thoracic aortic aneurysm (TAA) and identify circulating biomarkers associated with disease burden. BackgroundTAA is marked by progressive aortic wall weakening and dilation, predisposing to rupture and dissection. However, its cellular architecture remains incompletely defined, and reliable circulating biomarkers are lacking. MethodsSingle-cell RNA sequencing was performed on 17 aortic tissue samples from 10 patients undergoing TAA repair and integrated with publicly available datasets to characterize disease-associated cell states. In parallel, tomographic imaging and plasma proteomics were used to identify biomarkers associated with aortic diameter. Key findings were further assessed through integration with single-cell data, external validation, and in vitro stimulation of primary human adventitial fibroblasts with fibroblast growth factor 23 (FGF-23). ResultsWe identified 25 cellular subsets, including macrophages, endothelial cells, vascular smooth muscle cells, and fibroblasts, with substantial heterogeneity in cellular composition and transcriptional state. Genome-wide association study candidate genes, including JUN and TPM3, showed cell type-specific upregulation. Plasma proteomics identified multiple biomarkers associated with aortic diameter, of which FGF-23 was independently validated in the UK Biobank as elevated in individuals with TAA. FGFR1, the receptor for FGF-23, was selectively expressed in fibroblasts and subsets of vascular smooth muscle cells, with strongest downstream signaling in fibroblasts. FGF-23 stimulation induced inflammatory and extracellular matrix remodeling programs in primary human adventitial fibroblasts. ConclusionsThese findings define the cellular landscape of TAA and identify the FGF-23-FGFR1 axis as a biomarker-linked pathway that may contribute to aneurysm progression. Condensed AbstractThoracic aortic aneurysm (TAA) is characterized by progressive aortic dilation and risk of rupture, yet its cellular architecture and circulating biomarkers remain incompletely defined. We performed single-cell RNA sequencing on 17 aortic samples from 10 patients and integrated these data with public datasets to define the cellular landscape of TAA. In parallel, imaging and plasma proteomics (n=10) were used to identify biomarkers associated with aortic diameter. We identified 25 cellular subsets, including macrophages, endothelial cells, vascular smooth muscle cells, and fibroblasts, with notable transcriptional heterogeneity and cell type-specific upregulation of GWAS-associated genes (e.g., JUN, TPM3). Plasma proteomics identified fibroblast growth factor 23 (FGF-23) as associated with aortic diameter and elevated in TAA in the UK Biobank. FGFR1, its receptor, was selectively expressed in fibroblasts and VSMCs, and FGF-23 stimulation induced inflammatory and extracellular matrix remodeling programs in fibroblasts. These findings link a circulating biomarker to stromal cell signaling in TAA. HighlightsO_LIIntegrative single-cell RNA sequencing defined a diverse cellular landscape in thoracic aortic aneurysm tissue, identifying 25 distinct cell populations. C_LIO_LICross-dataset harmonization revealed marked differences in cellular composition across studies while supporting shared stromal and immune programs in thoracic aortic aneurysm. C_LIO_LIPlasma proteomics identified FGF-23 as a candidate biomarker associated with aortic diameter and independently linked to thoracic aortic aneurysm presence in the UK Biobank C_LIO_LIFGFR1 was enriched in fibroblasts and subsets of vascular smooth muscle cells, and FGF-23 induced inflammatory and extracellular matrix remodeling programs in human primary adventitial fibroblasts. C_LI

cell biology↗

bioRxiv2025

Comprehensive Multimodal Profiling of Atherosclerosis Reveals Bhlhe40 as a Potential Regulator of Vascular Smooth Muscle Cell Phenotypic Modulation

BackgroundVascular smooth muscle cells (VSMCs) play a central role in atherosclerosis by undergoing phenotypic modulation from a quiescent, contractile state to a range of synthetic phenotypes, including fibroblast-like, macrophage-like, and lipid-laden foam cell-like states. However, a comprehensive multimodal characterization and understanding of the transcriptional programs driving these transitions remain incomplete. MethodsTo comprehensively define the phenotypic diversity of VSMCs during atherosclerosis progression, we performed in-depth profiling using cellular indexing of transcriptomes and epitopes by sequencing (CITE-seq) and bulk RNA sequencing in a VSMC lineage-tracing atherosclerotic mouse model. Insights from these datasets guided the design of targeted in vitro experiments to investigate candidate regulatory mechanisms. ResultsSingle-cell multi-omics revealed extensive cellular heterogeneity within atherosclerotic plaques, including a rare population of VSMC-derived macrophage-like cells, whose presence was confirmed by histological analysis. These studies also identified a substantial population of VSMC-derived foam cells, comprising approximately 70% of all foam cells in the lesions. These cells exhibited activation of gene programs associated with lipid metabolism, proliferation, and tumor-like features. The transcription factor Bhlhe40 emerged as a key regulator of this phenotypic transition, with elevated expression in VSMC-derived foam cells during disease progression. Functional knockdown of Bhlhe40 suppressed VSMC phenotypic switching and foam cell characteristics, underscoring its potential role as a driver of VSMC modulation. ConclusionsThese findings advance our understanding of VSMC phenotypic modulation in atherosclerosis and highlight Bhlhe40 as a key regulator of this process. Elucidating the mechanisms governing VSMC plasticity may offer new therapeutic opportunities to reduce cardiovascular risk by targeting disease-driving cellular transitions.

molecular biology↗

bioRxiv2025

Single-Cell Multimodal Profiling Reveals a Novel CD26+ Fibroblast Subpopulation in Atherosclerosis

BackgroundAtherosclerosis involves complex interactions between lipids, immune cells, vascular smooth muscle cells (VSMCs), and fibroblasts within the arterial wall. While significant advances in single-cell technologies have shed light on the roles of immune cells and VSMCs in plaque development, fibroblasts remain underexplored, leaving critical gaps in understanding their contributions to disease progression and plaque stability. Comprehensive characterization of fibroblast phenotypes in atherosclerosis is essential to unravel their diverse functions and to distinguish between subsets that may play protective versus pathogenic roles in the disease process. MethodsHere, we utilized CITE-seq (Cellular Indexing of Transcriptomes and Epitopes by Sequencing) to comprehensively profile fibroblast diversity in a mouse model of atherosclerosis. Mice were fed an atherogenic diet for 0, 8, 19, and 26 weeks, representing distinct stages of disease progression, enabling a detailed phenotypic characterization of fibroblasts throughout the course of atherosclerosis development. ResultsWe identified four distinct fibroblast subpopulations, including a myofibroblast population closely resembling VSMC-derived chondromyocytes. The proportions of these fibroblast subsets exhibited a modest decline as atherosclerosis progressed. Through multimodal analysis, we identified CD26 as a highly expressed and specific marker for one of these fibroblast subpopulations, distinguishing it from other subsets. Using a combination of flow cytometry and immunohistochemistry, we demonstrated that CD26+ fibroblasts predominantly reside in the adventitia of healthy arteries. During atherosclerosis progression, these cells expand into the intima and primarily localize within the fibrous cap of the lesion. ConclusionsOur multi-omic analysis highlights the phenotypic diversity and dynamic changes of fibroblasts during atherosclerosis progression. Among these, CD26+ fibroblasts emerge as a distinct subpopulation that expands within atherosclerotic lesions and may play a critical role in promoting plaque stability through their migration into the fibrous cap.

genomics↗

bioRxiv2024

ADAMTS7 Promotes Smooth Muscle Cell Foam Cell Expansion in Atherosclerosis

Human genetic studies have repeatedly associated ADAMTS7 with atherosclerotic cardiovascular disease. Subsequent investigations in mice demonstrated that ADAMTS7 is proatherogenic and induced in response to vascular injury. However, the cell-specific mechanisms governing ADAMTS7 proatherogenicity remain unclear. To determine which vascular cell types express ADAMTS7, we interrogated single-cell RNA sequencing of human carotid atherosclerosis and found ADAMTS7 expression in smooth muscle cells (SMCs), endothelial cells (ECs), and fibroblasts. We subsequently created SMC- and EC-specific Adamts7 conditional knockout and transgenic mice. Conditional knockout of Adamts7 in either cell type does not reduce atherosclerosis, whereas transgenic induction in either cell type increases atherosclerosis. In SMC transgenic mice, this increase coincides with an expansion of lipid-laden SMC foam cells and a decrease in fibrous cap formation. RNA-sequencing in Adamts7 overexpressing SMCs revealed an upregulation of lipid genes typically assigned to macrophages. Mechanistically, ADAMTS7 increases SMC oxLDL uptake through CD36, whose expression is upregulated by PU.1. ATAC-seq and motif analysis revealed increased chromatin accessibility at AP-1 enriched regions, consistent with AP-1 dependent remodeling of PU.1-regulated lipid-handling loci. In summary, ADAMTS7 promotes atherosclerosis by driving SMC foam cell formation through an AP-1/PU.1/CD36 regulatory axis.

pathology↗

bioRxiv2024

Single-cell multimodal profiling of monocytes reveals diverse phenotypes and alterations linked to cardiovascular disease risks

Monocytes are a critical innate immune system cell type that serves homeostatic and immunoregulatory functions. The Cell surface expression of CD14 and CD16 has historically identified them, however, recent single-cell studies have uncovered that they are much more heterogeneous than previously realized. We utilized cellular indexing of transcriptomes and epitopes by sequencing (CITE-seq) and single-cell RNA sequencing (scRNA-seq) to describe the comprehensive transcriptional and phenotypic landscape of 437,126 monocytes. This high-dimensional multimodal approach identified vast phenotypic diversity and functionally distinct subsets, including IFN-responsive, MHCIIhi, monocyte-platelet aggregates, and non-classical, as well as several subpopulations of classical monocytes. Using flow cytometry, we validated the existence of MHCII+CD275+ MHCIIhi, CD42b+ monocyte-platelet aggregates, CD16+CD99- non-classical monocytes, and CD99+ classical monocytes. Each subpopulation exhibited unique functions, developmental trajectories, transcriptional regulation, and tissue distribution. Moreover, we revealed alterations associated with cardiovascular disease (CVD) risk factors, including race, smoking, and hyperlipidemia, and the effect of hyperlipidemia was recapitulated in mouse models of elevated cholesterol. This integrative and cross-species comparative analysis provides a unique resource to compare alterations in monocytes in pathological conditions and offers insights into monocyte-driven mechanisms in CVD and the potential for targeted therapies. SummaryMultimodal profiling provides a comprehensive phenotypic and transcriptional understanding of monocytes in health and cardiovascular disease risk states.

genomics↗

bioRxiv2023

Single-cell multimodal profiling of atherosclerosis identifies CD200 as a lineage marker of vascular smooth muscle cells and their derived cells

Vascular smooth muscle cells (VSMCs) play a central role in the development of atherosclerosis due in part to their capability to phenotypically transition into either a protective or harmful state. However, the ability to identify and trace VSMCs and their progeny in vivo is limited due to the lack of well-defined VSMC cell surface markers. Therefore, investigations into VSMC fate must utilize lineage-tracing mouse models, which are time-consuming and challenging to generate and not feasible in humans. Here, we employed CITE-seq to characterize the phenotypic expression of 119 cell surface proteins in mouse atherosclerosis. We found that CD200 is a highly expressed and specific marker of VSMCs, which persists even with phenotypic modulation. We validated our findings using a combination of flow cytometry, qPCR, and immunohistochemistry, all confirming that CD200 can identify and mark VSMCs and their derived cells in early to advanced mouse atherosclerotic lesions. Additionally, we describe a similar expression pattern of CD200 in human coronary and carotid atherosclerosis. Thus, our data support the use of CD200 as a lineage marker for VSMCs and VSMC-derived cells in mouse and human atherosclerosis.

molecular biology↗