KLF4-dependent phenotypic modulation of smooth muscle cells has a key role in atherosclerotic plaque pathogenesis

Advancements in the study of short-chain fatty acids and their therapeutic effects on atherosclerosis

Atherosclerosis (AS) remains a leading cause of cardiovascular disease and mortality globally. This chronic condition is characterized by inflammation, lipid accumulation, and the deposition of cellular components within arterial walls. Emerging evidence has highlighted the multifaceted therapeutic potential of short-chain fatty acids (SCFAs) in mitigating AS progression. SCFAs have demonstrated anti-inflammatory properties and the ability to regulate immune responses, metabolic pathways, vascular integrity, and intestinal barrier function in animal models of AS. Consequently, SCFAs have garnered significant attention as a promising approach for the prevention and treatment of AS. However, further clinical trials and studies are necessary to fully elucidate the underlying mechanisms and effects of SCFAs. Additionally, different types of SCFAs may exert distinct impacts, necessitating more in-depth investigation into their specific roles and mechanisms. This review provides an overview of the diverse cellular mechanisms contributing to AS formation, as well as a discussion of the significance of SCFAs in AS pathogenesis and their multifaceted therapeutic potential. Nonetheless, additional research is warranted to comprehensively understand and harness the potential of various SCFAs in the context of AS.

Generation of a novel constitutive smooth muscle cell-specific Myh11-driven Cre mouse model

Dysfunction in either embryonic or postnatal smooth muscle cells (SMCs) significantly contributes to the progression of various cardiovascular and visceral diseases. Therefore, elucidating the molecular mechanisms governing SMC development and homeostasis is crucial. MYH11 is the most reliable lineage gene for SMCs and has been utilized to develop tamoxifen-inducible Cre driver lines for achieving SMC-specific gene manipulation by crossing with mice carrying the loxP-flanked gene, particularly in adult mice. For studies involving SMCs during embryogenesis, the commonly used constitutive Cre driver is controlled by the Tagln (also known as SM22α) promoter. However, this Cre driver exhibits activity in multiple non-SMC populations, including cardiomyocytes and skeletal muscle precursors, introducing confounding effects. Additionally, most existing SMC-specific Cre drivers are generated using a transgenic approach, raising concerns about random site integration and variable gene copy numbers. To address these limitations, we report a novel Cre mouse model generated by knock-in (KI) of a nuclear-localized Cre recombinase into the Myh11 gene locus using homologous recombination. We confirmed that the Cre activity precisely recapitulates endogenous Myh11 expression by crossing with Rosa26 mTmG or tdTomato reporter mice. Moreover, Myh11-driven Cre can efficiently delete the floxed allele of the transcription factor Tead1 specifically in SMCs. The Tead1 SMC-specific knockout mice did not exhibit an overt phenotype, thereby circumventing the embryonic lethal phenotype mediated by Tagln-driven Cre, as we previously reported. These findings establish this novel Cre driver line as a robust tool for tracing the Myh11-positive SMC lineage and manipulating gene function specifically in SMCs during embryonic development in both male and female mice.

Extracellular matrix in vascular homeostasis and disease

The extracellular matrix is an essential component and constitutes a dynamic microenvironment of the vessel wall with an indispensable role in vascular homeostasis and disease. From early development through to ageing, the vascular extracellular matrix undergoes various biochemical and biomechanical alterations in response to diverse environmental cues and exerts precise regulatory control over vessel remodelling. Advances in novel technologies that enable the comprehensive evaluation of extracellular matrix components and cell-matrix interactions have led to the emergence of therapeutic strategies that specifically target this fine-tuned network. In this Review, we explore various aspects of extracellular matrix biology in vascular development, disorders and ageing, emphasizing the effect of the extracellular matrix on disease initiation and progression. Additionally, we provide an overview of the potential therapeutic implications of targeting the extracellular matrix microenvironment in vascular diseases.

The 9p21.3 Coronary Artery Disease Risk Locus Drives Vascular Smooth Muscle Cells to an Osteochondrogenic State

BACKGROUND

Genome-wide association studies have identified common genetic variants at ≈300 human genomic loci linked to coronary artery disease susceptibility. Among these genomic regions, the most impactful is the 9p21.3 coronary artery disease risk locus, which spans a 60-kb gene desert and encompasses ≈80 SNPs (single nucleotide polymorphism) in high linkage disequilibrium. Despite ≈2 decades since its discovery, the role of the 9p21.3 locus in cells of the vasculature remains incompletely resolved.

METHODS

We differentiated induced pluripotent stem cells (iPSCs) from risk, nonrisk donors at 9p21.3, and isogenic knockouts into vascular smooth muscle cells (VSMCs). We performed single-cell transcriptomic profiling, including coembedding and comparison with publicly available human arterial data sets. We conducted functional characterization using migration and calcification assays and confirmed our findings on iPSC-VSMCs derived from additional donors. Finally, we used overexpression of ANRIL followed by gene expression analysis.

RESULTS

We demonstrated that iPSC-VSMCs harboring the 9p21.3 risk haplotype preferentially adopt an osteochondrogenic state and show remarkable similarity to fibrochondrocytes from human artery tissue. The transcriptional profile and functional assessment of migration and calcification capacity across iPSC-VSMC lines from multiple donors concordantly resemble an osteochondrogenic state. Importantly, we identified numerous transcription factors driving different VSMC state trajectories. Additionally, we prioritized LIMCH1 and CRABP1 as signature genes critical for defining the risk transcriptional program. Finally, overexpression of a short isoform of ANRIL in 9p21.3 knockout cells was sufficient to induce the osteochondrogenic transcriptional signature.

CONCLUSIONS

Our study provides new insights into the mechanism of the 9p21.3 risk locus and defines its previously undescribed role in driving a disease-prone transcriptional and functional state in VSMCs concordant with an osteochondrogenic-like state. Our data suggest that the 9p21.3 risk haplotype likely promotes arterial calcification, through altered expression of ANRIL, in a cell type-specific and cell-autonomous manner, providing insight into potential risk assessment and treatment for carriers.

Unraveling the significance of innate inflammation in vascular disease

Atheroma formation is initiated by the activation of endothelial and smooth muscle cells, as well as immune cells, including neutrophils, lymphocytes, monocytes, macrophages, and dendritic cells. Monocytes, macrophages, and neutrophils are the innate immune cells that provide a rapid initial line of defence against vascular disease. These cells have a short lifespan and cannot retain memories, making them potential therapeutic targets for the inflammatory process associated with atherosclerosis. In addition, macrophages comprise the majority of vessel wall infiltrates and are, therefore, implicated in all stages of atherosclerosis progression. Neutrophils are the most common type of leukocyte found in circulation, and their high levels of matrix-degrading protease explain their significance in fibrous cap destabilization. However, the activation of immune cells becomes more complex by various microenvironmental stimuli and cytokines, which ultimately transform immune cells into their pro-inflammatory state. Different types of macrophage subsets with distinct functions in inflammation, such as M1 macrophages, cause an increase in pro-inflammatory cytokines and produce reactive oxygen species and nitric oxide, further worsening the disease. This review aims to shed light on immune-mediated inflammation in cardiovascular disease by focusing on the role of macrophage subsets in vascular inflammation and plaque stability, as well as the interaction between neutrophils and monocyte-macrophages.

Mechanisms and consequences of myeloid adhesome dysfunction in atherogenesis

AIMS

In the context of atherosclerosis, macrophages exposed to oxidized low-density lipoproteins (oxLDLs) exhibit cellular abnormalities, specifically in adhesome functions, yet the mechanisms and implications of these adhesive dysfunctions remain largely unexplored.

METHODS AND RESULTS

This study reveals a significant depletion of Kindlin3 (K3) or Fermt3, an essential component of the adhesome regulating integrin functions, in macrophages located within atherosclerotic plaques in vivo and following oxLDL exposure in vitro. To examine the effects of K3 deficiency, the study utilized hyperlipidaemic bone marrow chimeras devoid of myeloid Kindlin3 expression. The absence of myeloid K3 increased atherosclerotic plaque burden in the aortas in vivo and enhanced lipid accumulation and lipoprotein uptake in macrophages from Kindlin3-null chimeric mice in vitro. Importantly, re-expression of K3 in macrophages ameliorated these abnormalities. RNA sequencing of bone marrow-derived macrophages (BMDM) from K3-deficient mice revealed extensive deregulation in adhesion-related pathways, echoing changes observed in wild-type cells treated with oxLDL. Notably, there was an increase in Olr1 expression [encoding the lectin-like oxidized LDL receptor-1 (LOX1)], a gene implicated in atherogenesis. The disrupted K3-integrin axis in macrophages led to a significant elevation in the LOX1 receptor, contributing to increased oxLDL uptake and foam cell formation. Inhibition of LOX1 normalized lipid uptake in Kindlin3-null macrophages. A similar proatherogenic phenotype, marked by increased macrophage LOX1 expression and foam cell formation, was observed in myeloid-specific Itgβ1-deficient mice but not in Itgβ2-deficient mice, underscoring the critical role of K3/Itgβ1 interaction.

CONCLUSION

This study shows that the loss of Kindlin3 in macrophages upon exposure to oxLDL leads to adhesome dysfunction in atherosclerosis and reveals the pivotal role of Kindlin3 in macrophage function and its contribution to the progression of atherosclerosis, providing valuable insights into the molecular mechanisms that could be targeted for therapeutic interventions.

Adventitial fibroblasts direct smooth muscle cell-state transition in pulmonary vascular disease

Background

Pulmonary vascular remodeling is a progressive pathological process characterized by functional alterations within pulmonary artery smooth muscle cells (PASMCs) and adventitial fibroblasts (PAAFs). Mechanisms driving the transition to a diseased phenotype remain elusive.

Methods

We combined transcriptomic and proteomic profiling with phenotypic characterization of source-matched cells from healthy controls and individuals with idiopathic pulmonary arterial hypertension (IPAH). Bidirectional cellular crosstalk was examined using direct and indirect co-culture models, and phenotypic responses were assessed via transcriptome analysis.

Results

PASMC and PAAF undergo distinct phenotypic shifts during pulmonary vascular remodeling, with limited shared features, such as reduced mitochondrial content and hyperpolarization. IPAH-PASMC exhibit increased glycosaminoglycan production and downregulation of contractile machinery, while IPAH-PAAF display a hyperproliferative phenotype. We identified alterations in extracellular matrix components, including laminin and collagen, alongside pentraxin-3 and hepatocyte growth factor, as potential regulators of PASMC phenotypic transitions mediated by PAAF.

Conclusions

While PASMCs and PAAFs retain their core cellular identities, they acquire distinct disease-associated states. These findings provide new insights into the dynamic interplay of pulmonary vascular mesenchymal cells in disease pathogenesis.

Funding

This work was supported by Cardio-Pulmonary Institute EXC 2026 390649896 (GK) and Austrian Science Fund (FWF) grant I 4651-B (SC).

Palmitic acid induces cardiomyocyte apoptosis by enhancing the KLF4/cMLCK signaling pathway

Hyperlipidemia and myocardial apoptosis caused by myocardial ischemia are the main causes of high mortality rates in cardiovascular diseases. Previous studies have indicated that Krüppel-like factor 4 (KLF4) is involved in the induction of cardiac myocyte apoptosis under various stress conditions. In current study, we discovered that KLF4 also participates in palmitic acid (PA)-induced cardiac myocyte apoptosis. However, the specific mechanisms by which KLF4 regulates cardiac myocyte apoptosis remain unclear. Cardiac myosin light-chain kinase (cMLCK) is a crucial enzyme involved in regulating cardiac myocyte contraction and is closely associated with the regulation of apoptosis. Here, we employed the lipotoxicity in vitro and in vivo models to explore the potential synergistic role of KLF4 and cMLCK in cardiac myocyte apoptosis. Our findings demonstrate that under the influence of PA, upregulation of KLF4 expression accompanied by downregulation of cMLCK expression leads to cardiomyocyte apoptosis and cell proliferation inhibition. Selective knockdown and overexpression of KLF4 in cardiomyocytes further confirmed the involvement of KLF4 in PA-induced cardiomyocyte apoptosis. Likewise, overexpression of cMLCK alleviated PA-induced cardiac myocyte apoptosis. Our study reveals the pro-apoptotic effect of KLF4 and elucidates the specific mechanism by which the KLF4/cMLCK signaling pathway is involved in PA-induced cardiac myocyte apoptosis, providing new therapeutic targets for cardiovascular disease treatment.

The Atherosclerotic Plaque Microenvironment as a Therapeutic Target

PURPOSE OF REVIEW

Atherosclerosis is traditionally viewed as a disease triggered by lipid accumulation, but growing evidence underscores the crucial role of the plaque microenvironment in disease progression. This review explores recent advances in understanding how cellular and extracellular components of the plaque milieu drive atherosclerosis, with a focus on leveraging these microenvironmental factors for therapeutic intervention. This review highlights recent advances in cell-cell crosstalk and matrix remodeling, offering insights into innovative therapeutic strategies for atherosclerotic cardiovascular disease.

RECENT FINDINGS

While atherosclerosis begins with the subendothelial retention of apolipoprotein B (ApoB)-containing lipoproteins​, its progression is increasingly recognized as a consequence of complex cellular and extracellular dynamics within the plaque microenvironment. Soluble factors and extracellular matrix proteins shape mechanical properties and the biochemical landscape, directly influencing cell behavior and inflammatory signaling. For instance, the deposition of transitional matrix proteins, such as fibronectin, in regions of disturbed flow primes endothelial cells for inflammation​. Likewise, impaired clearance of dead cells and chronic extracellular matrix remodeling contribute to lesion expansion and instability, further exacerbating disease severity. Targeting the plaque microenvironment presents a promising avenue for stabilizing atherosclerotic lesions. Approaches that enhance beneficial cellular interactions, such as boosting macrophage efferocytosis to resolve inflammation while mitigating proatherogenic signals like integrin-mediated endothelial activation, may promote fibrous cap formation and reduce plaque vulnerability. Harnessing these mechanisms may lead to novel therapeutic approaches aimed at modifying the plaque microenvironment to combat atherosclerotic cardiovascular disease.

C/EBPβ activation in vascular smooth muscle cells promotes hyperlipidemia-induced phenotypic transition and arterial stiffness

Arterial stiffness is a critical factor in cardiovascular and cerebrovascular events, yet clinical practice lacks specific therapeutic targets and biomarkers for its assessment. Hyperlipidemia closely correlates with arterial stiffness, and we observed elevated CCAAT/enhancer-binding protein β (C/EBPβ) expression in atherosclerotic mouse arterial walls. As the arterial medial layer predominantly consists of vascular smooth muscle cells (VSMCs), C/EBPβ's role in VSMCs under hyperlipidemia remains unclear. Our findings demonstrate that cholesterol-induced phenotypic transition of contractile VSMCs to macrophage-like cells coincides with C/EBPβ upregulation and activation. The activation of C/EBPβ is closely related to cellular assembly and organization, regulating the cytoskeleton via Disheveled-associated activator of morphogenesis 1 (Daam1). Conditional knockout of C/EBPβ in VSMCs of ApoE-/- mice alleviated hyperlipidemia-induced vascular remodeling and reduced the elevation of aortic pulse wave velocity. Additionally, C/EBPβ-regulated cytokine platelet-derived growth factor-CC (PDGF-CC) is correlated with brachial-ankle pulse wave velocity in humans. These results indicate that the activation of C/EBPβ promotes the transition of VSMCs from a contractile phenotype to a macrophage-like phenotype by regulating morphological changes, and C/EBPβ activation contributes to hyperlipidemia-induced arterial stiffness. PDGF-CC exhibited a significant association with arterial stiffness and may serve as a promising indicator of arterial stiffness in humans. Our study reveals molecular mechanisms behind hyperlipidemia-induced arterial stiffness and provides potential therapeutic targets and biomarkers.

Redefining Macrophage Heterogeneity in Atherosclerosis: A Focus on Possible Therapeutic Implications

Atherosclerosis is a lipid disorder where modified lipids (especially oxidized LDL) induce macrophage foam cell formation in the aorta. Its pathogenesis involves a continuum of persistent inflammation accompanied by dysregulated anti-inflammatory responses. Changes in the immune cell status due to differences in the lesional microenvironment are crucial in terms of plaque development, its progression, and plaque rupture. Ly6Chi monocytes generated through both medullary and extramedullary cascades act as one of the major sources of plaque macrophages and thereby foam cells. Both monocytes and monocyte-derived macrophages also participate in pathological events in atherosclerosis-associated multiple organ systems through inter-organ communications. For years, macrophage phenotypes M1 and M2 have been shown to perpetuate inflammatory and resolution responses; nevertheless, such a dualistic classification is too simplistic and contains severe drawbacks. As the lesion microenvironment is enriched with multiple mediators that possess the ability to activate macrophages to diverse phenotypes, it is obvious that such cells should demonstrate substantial heterogeneity. Considerable research in this regard has indicated the presence of additional macrophage phenotypes that are exclusive to atherosclerotic plaques, namely Mox, M4, Mhem, and M(Hb) type. Furthermore, although the concept of macrophage clusters has come to the fore in recent years with the evolution of high-dimensional techniques, classifications based on such 'OMICS' approaches require extensive functional validation as well as metabolic phenotyping. Bearing this in mind, the current review provides an overview of the status of different macrophage populations and their role during atherosclerosis and also outlines possible therapeutic implications.

Age-Related Impairments in Immune Cell Efferocytosis and Autophagy Hinder Atherosclerosis Regression

BACKGROUND

Aging is a well-established risk factor for the development and progression of atherosclerosis, but the molecular mechanisms underlying this relationship remain poorly defined, and its role in atherosclerosis regression is unknown. To uncover age-related alterations that may impair atherosclerosis regression, we investigated the response of young and old macrophages to atherogenic lipoproteins in vitro and in vivo.

METHODS

Metabolic and proteomic studies were performed in vitro using macrophages differentiated from the bone marrow of young or old mice. To test the role of immune cell aging in atherosclerosis regression, bone marrow from young and old donors was transplanted into irradiated young recipient mice expressing gain-of-function AAV-PCSK9 (adeno-associated virus-proprotein convertase subtilisin/kexin type 9). Following 14 weeks of Western diet feeding, atherosclerosis regression was induced by switching to a standard laboratory diet for 4 weeks.

RESULTS

Compared with young macrophages, old macrophages accumulated more lipid droplets upon lipid loading with the pro-atherogenic lipoprotein aggregated LDL (low-density lipoprotein), accompanied by a failure to proportionally induce autophagy and cholesterol efflux. Proteomic analysis of bone marrow-derived macrophages revealed that pathways related to endocytosis, engulfment, and phagocytosis were downregulated in old lipid-loaded macrophages. Functional studies confirmed a reduction in efferocytic capacity in old macrophages. In recipient mice transplanted with old bone marrow, atherosclerosis regression was impaired, as evidenced by inefficient resolution of circulating inflammatory cell levels, reduced activation of plaque autophagy and apoptotic cell clearance, and persistent plaque CD45+ and CD68+ content.

CONCLUSIONS

Aging impairs macrophage function through reduced efferocytosis and autophagy activation, limiting atherosclerosis regression. These results highlight the need to better define the mechanisms linking aging to atherosclerosis to develop targeted therapies for the aging population.

Measuring contractile forces in vascular smooth muscle cells

Vascular smooth muscle cell (VSMC) contractility mediates blood vessel tone. Abnormalities in VSMC function and in blood vessel tone can contribute to a variety of cardiovascular diseases. This review examines the role of VSMC contractile force in vascular disease, divided into two primary sections. The first section introducing VSMC mechanical contraction and detailing the molecular mechanisms of VSMC contractility in normal and pathological states. The second section exploring methods of measuring contraction in VSMCs, such as Ca2+ imaging, myography, and traction force microscopy, and highlighting where each method is of best use. Understanding the mechanical properties and contractile profiles of VSMCs offers valuable insights into disease mechanisms. By investigating these aspects, this review describes the potential of VSMC contractile forces as diagnostic markers and therapeutic targets in vascular disease.

KLF4 promotes a KRT13+ hillock-like state in squamous lung cancer

Lung squamous cell carcinoma (LUSC) is basal-like subtype of lung cancer with limited treatment options. While prior studies have identified tumor-propagating cell states in squamous tumors, the broader landscape of intra-tumoral heterogeneity within LUSC remains poorly understood. Here, we employ Sox2-driven mouse models, organoid cultures, and single-cell transcriptomic analyses to uncover previously unrecognized levels of cell fate diversity within LUSC. Specifically, we identify a KRT13+ hillock-like population of slower-dividing tumor cells characterized by immunomodulatory gene expression signatures. The tumor hillock-like state is conserved across multiple animal models and is present in the majority of human LUSCs as well as head and neck and esophageal squamous tumors. Our findings shed light on the cellular origins of lung hillock-like states: normal club cells give rise to tumors with luminal hillock-like populations, while basal-like tumor-propagating cells transition into basal hillock-like states, resembling homeostatic cellular responses to lung injury. Mechanistically, we identify KLF4 as a key transcriptional regulator of the hillock-like state, both necessary and sufficient to induce KRT13 expression. Together, these results provide new molecular insights into cell fate plasticity that underlies intra-tumoral heterogeneity in LUSC, offering potential avenues for new therapeutic strategies.

Hypercholesterolemia-induced LXR signaling in smooth muscle cells contributes to vascular lesion remodeling and visceral function

Vascular smooth muscle cells (VSMC) are the most abundant cell type in the artery's media layer and regulate vascular tone and lesion remodeling during atherogenesis. Like monocyte-derived macrophages, VSMCs accumulate excess lipids and contribute to the total intimal foam cell population in human coronary plaques and mouse aortic atheroma. While there are extensive studies characterizing the contribution of lipid metabolism in macrophage immunometabolic responses in atherosclerotic plaques, the role of VSMC lipid metabolism in regulating vascular function and lesion remodeling in vivo remains poorly understood. Here, we report that the liver X receptor (LXR) signaling pathway in VSMC is continuously activated during atherogenesis. Notably, we found that LXR deficiency in SMCs under hypercholesterolemic conditions influenced lesion remodeling by altering the fate of dedifferentiated SMCs and promoting the accumulation of VSMC-derived transitional cells. This phenotypic switching was accompanied by reduced indices of plaque stability, characterized by a larger necrotic core area and reduced fibrous cap thickness. Moreover, SMC-specific LXR deficiency impaired vascular function and caused visceral myopathy characterized by maladaptive bladder remodeling and gut lipid malabsorption. Mechanistically, we found that the expression of several genes involved in cholesterol efflux and FA synthesis including Abca1, Srebf1, Scd1, Scd2, Acsl3, and Mid1ip1 was downregulated in mice lacking LXRαβ in SMCs, likely contributing to the phenotypic switching of VSMC in the atherosclerotic lesions.

The RNA-binding protein RBPMS inhibits smooth muscle cell-driven vascular remodeling in atherosclerosis and vascular injury

Atherosclerosis and vessel wall trauma induce vascular smooth muscle cell (VSMC) phenotypic modulation, leading to plaque cap growth and postintervention restenosis. Our systems biology approach identified RNA binding protein, mRNA processing factor (RBPMS) as a conserved, VSMC-specific gene associated with VSMC modulation in atherosclerosis. RBPMS gene expression positively correlates with VSMC contractile markers in human and murine atherosclerotic arteries as well as in two vascular injury models during the postinjury intimal hyperplasia phase. RBPMS promotes contractile VSMC differentiation, reduces plaque cap development in high-fat diet-fed apolipoprotein E-null (ApoE-/-) murine atherosclerotic arteries, and inhibits intimal hyperplasia. Mechanistically, the RBPMS protein interacts with the myocardin (MYOCD) pre-mRNA and enhances MYOCD_v3/MYOCD_v1 transcript balance through alternative exon 2a splicing. RBPMS promotes the VSMC contractile phenotype and reduces their fibroproliferative activity in a MYOCD_v3a-dependent manner. RBPMS enhances Myocd_v3/Myocd_v1 transcript balance in both atherosclerotic and injured vessels. RBPMS may inhibit VSMC-driven plaque cap development and intervention-induced restenosis.

Shared molecular, cellular, and environmental hallmarks in cardiovascular disease and cancer: Any place for drug repurposing?

Cancer and cardiovascular disease (CVD) are the 2 biggest killers worldwide. Specific treatments have been developed for the 2 diseases. However, mutual therapeutic targets should be considered because of the overlap of cellular and molecular mechanisms. Cancer research has grown at a fast pace, leading to an increasing number of new mechanistic treatments. Some of these drugs could prove useful for treating CVD, which realizes the concept of cancer drug repurposing. This review provides a comprehensive outline of the shared hallmarks of cancer and CVD, primarily ischemic heart disease and heart failure. We focus on chronic inflammation, altered immune response, stromal and vascular cell activation, and underlying signaling pathways causing pathological tissue remodeling. There is an obvious scope for targeting those shared mechanisms, thereby achieving reciprocal preventive and therapeutic benefits. Major attention is devoted to illustrating the logic, advantages, challenges, and viable examples of drug repurposing and discussing the potential influence of sex, gender, age, and ethnicity in realizing this approach. Artificial intelligence will help to refine the personalized application of drug repurposing for patients with CVD. SIGNIFICANCE STATEMENT: Cancer and cardiovascular disease (CVD), the 2 biggest killers worldwide, share several underlying cellular and molecular mechanisms. So far, specific therapies have been developed to tackle the 2 diseases. However, the development of new cardiovascular drugs has been slow compared with cancer drugs. Understanding the intersection between pathological mechanisms of the 2 diseases provides the basis for repurposing cancer therapeutics for CVD treatment. This approach could allow the rapid development of new drugs for patients with CVDs.

RNA splicing of the STAT3 by PCBP1 promotes vulnerable plaque formation via macrophage-like phenotype modulation of vascular smooth muscle cell

BACKGROUND

The increase of macrophage-like vascular smooth muscle cells (VSMCs) within atherosclerotic plaques significantly contributes to plaque vulnerability. The STAT3 signaling is crucial in maintaining the contractile phenotype of VSMCs. Recent studies have identified two isoforms of STAT3, STAT3α and STAT3β, generated through alternative splicing. However, the roles of these isoforms in VSMC phenotypic transformation and plaque vulnerability are not yet clear.

METHODS

In this study, we examined the differential expression of STAT3α and STAT3β in vulnerable and stable plaque tissues, and their correlation with the content of macrophage-like VSMCs. Utilizing in vivo and in vitro experiments, we elucidated the regulatory mechanisms of STAT3 alternative splicing and the molecular mechanisms by which STAT3β induces the transformation of VSMCs into the macrophage-like phenotype.

RESULTS

We observed a significant upregulation of STAT3β within macrophage-like VSMCs in vulnerable plaque tissues. Upregulation of STAT3β, not merely the downregulation of STAT3α, drives the transformation of VSMCs into the macrophage-like phenotype. The splicing factor PCBP1 binds to exon 23 of the STAT3 gene, suppressing the expression of STAT3β. Furthermore, STAT3β negatively regulates the expression of the acetyltransferase enzyme KAT2B, which in turn, inhibits the key transcription factor KLF4 associated with the macrophage-like phenotype.

CONCLUSION

Our findings provide insights into the role of STAT3β isoforms in plaque stability and the phenotypic flexibility of VSMCs, highlighting potential targets for therapeutic intervention in atherosclerosis.

New insights into the relationship of mitochondrial metabolism and atherosclerosis

Atherosclerotic cardiovascular and cerebrovascular diseases are the number one killer of human health. In view of the important role of mitochondria in the formation and evolution of atherosclerosis, our manuscript aims to comprehensively elaborate the relationship between mitochondria and the formation and evolution of atherosclerosis from the aspects of mitochondrial dynamics, mitochondria-organelle interaction (communication), mitochondria and cell death, mitochondria and vascular smooth muscle cell phenotypic switch, etc., which is combined with genome, transcriptome and proteome, in order to provide new ideas for the pathogenesis of atherosclerosis and the diagnosis and treatment of related diseases.

Unravelling molecular mechanisms in atherosclerosis using cellular models and omics technologies

Despite the discovery and prevalent clinical use of potent lipid-lowering therapies, including statins and PCSK9 inhibitors, cardiovascular diseases (CVD) caused by atherosclerosis remain a large unmet clinical need, accounting for frequent deaths worldwide. The pathogenesis of atherosclerosis is a complex process underlying the presence of modifiable and non-modifiable risk factors affecting several cell types including endothelial cells (ECs), monocytes/macrophages, smooth muscle cells (SMCs) and T cells. Heterogeneous composition of the plaque and its morphology could lead to rupture or erosion causing thrombosis, even a sudden death. To decipher this complexity, various cell model systems have been developed. With recent advances in systems biology approaches and single or multi-omics methods researchers can elucidate specific cell types, molecules and signalling pathways contributing to certain stages of disease progression. Compared with animals, in vitro models are economical, easily adjusted for high-throughput work, offering mechanistic insights. Hereby, we review the latest work performed employing the cellular models of atherosclerosis to generate a variety of omics data. We summarize their outputs and the impact they had in the field. Challenges in the translatability of the omics data obtained from the cell models will be discussed along with future perspectives.

SMC Abca1 and Abcg1 Deficiency Enhances Urinary Bladder Distension but Not Atherosclerosis

BACKGROUND

Smooth muscle cells (SMCs) regulate blood flow distribution via vasoconstriction mediated by α-ARs (α-adrenergic receptors). Plasma membrane cholesterol accumulation affects α1-AR signaling and promotes loss of SMC contractile markers in vitro. ABCA1 and ABCG1 (ATP-binding cassette transporter A1 and G1) mediate cholesterol efflux to HDL (high-density lipoprotein). ABCA1/ABCG1 show high expression in medial and low expression in intimal SMCs of atherosclerotic plaques. The role of ABCA1 and ABCG1 in SMC-mediated vasoconstriction and atherogenesis remains poorly understood.

METHODS

We generated mice with SMC-specific Abca1/Abcg1 deficiency on the low-density lipoprotein receptor-deficient (Ldlr-/-) background by crossbreeding Abca1fl/flAbcg1fl/flLdlr-/- mice with Myh11CreERT2 transgenic mice. To induce SMC cholesterol accumulation and atherogenesis, we fed Myh11CreERT2Abca1fl/flAbcg1fl/flLdlr-/-, Myh11CreERT2Abca1fl/flLdlr-/-, Myh11CreERT2Abcg1fl/flLdlr-/-, and Myh11CreERT2Ldlr-/- mice Western-type diet for 16 weeks.

RESULTS

Combined SMC-Abca1/Abcg1 deficiency increased vasoconstriction in aortic rings induced by the α1-AR agonist phenylephrine. Unexpectedly, SMC-Abca1/Abcg1 deficiency induced urinary bladder distension by >20-fold. This was reversed by the α1-AR antagonist tamsulosin, indicating its dependence on bladder neck SMC constriction. Moreover, SMC-Abca1/Abcg1 deficiency decreased contractile markers and increased macrophage and fibroblast markers in bladder SMCs, indicating SMC transdifferentiation. This was accompanied by free cholesterol accumulation and increased endoplasmic reticulum stress. SMC-Abca1/Abcg1 deficiency did not induce thoracic aorta SMC transdifferentiation, presumably due to increased cholesteryl ester accumulation and no endoplasmic reticulum stress in thoracic aorta SMCs. Surprisingly, SMC-Abca1/Abcg1 deficiency did not affect atherosclerotic lesion size or composition in the aortic root or brachiocephalic artery.

CONCLUSIONS

We uncover a new role of SMC cholesterol efflux pathways in suppressing α1-AR-mediated vasoconstriction and bladder SMC transdifferentiation, decreasing urinary bladder distension. Our data may provide a mechanistic link for the association between urinary bladder distension and diabetes in humans, particularly because diabetes is associated with decreased cholesterol efflux. SMC-Abca1/Abcg1 deficiency did not affect atherosclerotic lesion size or plaque composition, presumably due to low expression of Abca1/Abcg1 in intimal SMCs.

PRDM16 controls smooth muscle cell fate in atherosclerosis

Vascular smooth muscle cells (SMCs) normally exist in a contractile state but can undergo fate switching to produce various cell phenotypes in response to pathologic stimuli 1-3 . In atherosclerosis, these phenotypically modulated SMCs regulate plaque composition and influence the risk of major adverse cardiovascular events 4,5 . We found that PRDM16, a transcription factor that is genetically associated with cardiovascular disease, is highly expressed in arterial SMCs and downregulated during SMC fate switching in human and mouse atherosclerosis. Loss of Prdm16 in SMCs of mice activates a synthetic modulation program under homeostatic conditions. Single cell analyses show that loss of Prdm16 drives a synthetic program in all SMC populations. Upon exposure to atherogenic stimuli, SMC-selective Prdm16 deficient mice develop SMC-rich, fibroproliferative plaques that contain few foam cells. Acute loss of Prdm16 results in the formation of collagen-rich lesions with thick fibrous caps. Reciprocally, increasing PRDM16 expression in SMCs blocks synthetic processes, including migration, proliferation, and fibrosis. Mechanistically, PRDM16 binds to chromatin and decreases activating histone marks at synthetic genes. Altogether, these results define PRDM16 as a critical determinant of SMC identity and atherosclerotic lesion composition.

Exploring Origin-Dependent Susceptibility of Smooth Muscle Cells to Aortic Diseases Through Intersectional Genetics

BACKGROUND

The developmental diversity among smooth muscle cells (SMCs) plays a crucial role in segment-specific aortic diseases. However, traditional genetic approaches are inadequate for enabling in vivo analysis of disease susceptibility associated with cellular origin. There is an urgent need to build genetic technologies that target different developmental origins to investigate the mechanisms of aortopathies, thereby facilitating the development of effective therapeutics.

METHODS

To address this challenge, we developed an advanced dual recombinase-mediated intersectional genetic system, specifically designed to precisely target SMCs from various developmental origins in mice. Specifically, we used Isl1-Dre, Wnt1-Dre, Meox1-DreER, and Upk3b-Dre to target SMC progenitors from the second heart field, cardiac neural crest, somites, and mesothelium, respectively. This system was combined with single-cell RNA sequencing to investigate the impact of TGF-β (transforming growth factor-β) signaling in different segments of the aorta by selectively knocking out Tgfbr2 in the ascending aorta and Smad4 in the aortic arch, respectively.

RESULTS

Through intersectional genetic approaches, we use the Myh11-Cre(ER) driver along with origin-specific Dre drivers to trace cells of diverse developmental origins within the SMC population. We found that a deficiency of Tgfbr2 in SMCs of the ascending aorta leads to aneurysm formation in this specific region. We also demonstrate the critical role of Smad4 in preserving aortic wall integrity and homeostasis in SMCs of the aortic arch.

CONCLUSIONS

Our approach to genetically targeting SMC subtypes provides a novel platform for exploring origin-dependent or location-specific aortic vascular diseases. This genetic system enables comprehensive analysis of contributions from different cell lineages to SMC behavior and pathology, thereby paving the way for targeted research and therapeutic interventions in the future.

The 9p21.3 coronary artery disease risk locus drives vascular smooth muscle cells to an osteochondrogenic state

Background

Genome-wide association studies have identified common genetic variants at ~300 human genomic loci linked to coronary artery disease (CAD) susceptibility. Among these genomic regions, the most impactful is the 9p21.3 CAD risk locus, which spans a 60 kb gene desert and encompasses ~80 SNPs in high linkage disequilibrium. Despite nearly two decades since its discovery, the role of the 9p21.3 locus in cells of the vasculature remains incompletely resolved.

Methods

We differentiated induced pluripotent stem cells (iPSCs) from risk and non-risk donors at 9p21.3 into vascular smooth muscle cells. We performed single-cell transcriptomic profiling, including co-embedding and comparison with publicly available human arterial datasets. We conducted functional characterization using migration and calcification assays and confirmed our findings on iPSC-VSMCs derived from additional donors. Finally, we used overexpression of ANRIL followed by gene expression analysis.

Results

We demonstrated that iPSC-VSMCs harboring the 9p21.3 risk haplotype preferentially adopt an osteochondrogenic state and show remarkable similarity to fibrochondrocytes from human artery tissue. The transcriptional profile and functional assessment of migration and calcification capacity across iPSC-VSMCs lines from multiple donors concordantly resemble an osteochondrogenic state. Importantly, we identified numerous transcription factors driving different VSMC state trajectories. Additionally, we prioritized LIMCH1 and CRABP1 as signature genes critical for defining the risk transcriptional program. Finally, overexpression of a short isoform of ANRIL in non-risk cells was sufficient to induce the osteochondrogenic transcriptional signature.

Conclusions

Our study provides new insights into the mechanism of the 9p21.3 risk locus and defines its previously undescribed role in driving a disease-prone transcriptional and functional state in VSMCs concordant with an osteochondrogenic-like state. Our data suggest that the 9p21.3 risk haplotype likely promotes arterial calcification, through altered expression of ANRIL, in a cell-type specific and cell-autonomous manner, providing insight into potential risk assessment and treatment for carriers.

Epigenetic regulation of vascular smooth muscle cell phenotypes in atherosclerosis

Vascular smooth muscle cells (VSMCs) in adult arteries maintain substantial phenotypic plasticity, which allows for the reversible cell state changes that enable vascular remodelling and homeostasis. In atherosclerosis, VSMCs dedifferentiate in response to lipid accumulation and inflammation, resulting in loss of their characteristic contractile state. Recent studies showed that individual, pre-existing VSMCs expand clonally and can acquire many different phenotypes in atherosclerotic lesions. The changes in gene expression underlying this phenotypic diversity are mediated by epigenetic modifications which affect transcription factor access and thereby gene expression dynamics. Additionally, epigenetic mechanisms can maintain cellular memory, potentially facilitating reversion to the contractile state. While technological advances have provided some insight, a comprehensive understanding of how VSMC phenotypes are governed in disease remains elusive. Here we review current literature in light of novel insight from studies at single-cell resolution. We also discuss how lessons from epigenetic studies of cellular regulation in other fields could help in translating the potential of targeting VSMC phenotype conversion into novel therapies in cardiovascular disease.

Long Non-Coding RNA Function in Smooth Muscle Cell Plasticity and Atherosclerosis

In the healthy mature artery, vascular cells, including endothelial cells, smooth muscle cells (SMCs), and fibroblasts are organized in different layers, performing specific functions. SMCs located in the media are in a differentiated state and exhibit a contractile phenotype. However, in response to vascular injury within the intima, stimuli from activated endothelial cells and recruited inflammatory cells reach SMCs and induce a series of remodeling events in them, known as phenotypic switching. Indeed, SMCs retain a certain degree of plasticity and are able to transdifferentiate into other cell types that are crucial for both the formation and development of atherosclerotic lesions. Because of their highly cell-specific expression profiles and their widely recognized contribution to physiological and disease-related biological processes, long non-coding RNAs have received increasing attention in atherosclerosis research. Dynamic fluctuations in their expression have been implicated in the regulation of SMC identity. Sophisticated technologies are now available to allow researchers to access single-cell transcriptomes and study long non-coding RNA function with unprecedented precision. Here, we discuss the state of the art of long non-coding RNAs regulation of SMC phenotypic switching, describing the methodologies used to approach this issue and evaluating the therapeutic perspectives of exploiting long non-coding RNAs as targets in atherosclerosis.

TEAD1-Mediated Trans-Differentiation of Vascular Smooth Muscle Cells into Fibroblast-Like Cells Contributes to the Stabilization and Repair of Disrupted Atherosclerotic Plaques

Atherosclerotic plaque rupture mainly contributes to acute coronary syndrome (ACS). Insufficient repair of these plaques leads to thrombosis and subsequent ACS. Central to this process is the modulation of vascular smooth muscle cells (VSMCs) phenotypes, emphasizing their pivotal role in atherosclerotic plaque stability and healing post-disruption. Here, an expansion of FSP1+ cells in a tandem stenosis (TS) model of atherosclerotic mice is unveiled, predominantly originating from VSMCs through single-cell RNA sequencing (scRNA-seq) analyses and VSMC lineage tracing studies. Further investigation identified TEA domain transcription factor 1 (TEAD1) as the key transcription factor driving the trans-differentiation of VSMCs into fibroblast-like cells. In vivo experiments using a TS model of plaque rupture demonstrated that TEAD1 played a crucial role in promoting plaque stability and healing post-rupture through pharmacological or TEAD1-AAV treatments. Mechanistically, it is found that TEAD1 promoted the expression of fibroblast markers through the Wnt4/β-Catenin pathway, facilitating the trans-differentiation. Thus, this study illustrated that TEAD1 played a critical role in promoting the trans-differentiation of VSMCs into fibroblast-like cells and subsequent extracellular matrix production through the Wnt4/β-Catenin pathway. Consequently, this process enhanced the healing mechanisms following plaque rupture, elucidating potential therapeutic avenues for managing atherosclerotic instability.

Nox1/PAK1 is required for angiotensin II-induced vascular inflammation and abdominal aortic aneurysm formation

NADPH oxidase 1 (Nox1) is a major isoform of Nox in vascular smooth muscle cells (VSMCs). VSMC activation and extracellular matrix (ECM) remodelling induce abdominal aortic aneurysm (AAA). In this study, we aim to determine the role of Nox1 in the progression of AAA and explore the underling mechanism. ApoE-/-Nox1SMCko mice in which the Nox1 gene was smooth muscle cell (SMC)-specifically deleted in ApoE-/- background, were infused with angiotensin II (Ang II) for 28 days. We found the Nox1 deficiency reduced AAA formation and increased survival compared with ApoE-/-Nox1y/flox mice. Abdominal aortic ROS and monocyts/macrophages were reduced in the ApoE-/-Nox1SMCko mice after Ang II-infusion. The SMC-specific Nox1 deletion caused less elastin fragments and lower matrix metalloproteinase (MMP) activities in the abdominal aorta. Further, we found the Nox1 protein interacted with p21-activated kinase 1 (PAK1) in Ang II-stimulated VSMCs. The PAK1, controlled by Nox1/ROS, promoted VSMC proliferation, migration and differentiation; this is associated with increased activities of vimentin and cofilin, and cytoskeleton modulation. Moreover, we found that the Nox1/PAK1 activated the downstream MAPKs (ERK1/2, p38 and JNKs) and NF-κB, and upregulated Sp1-mediated MMP2 expression upon Ang II-stimulation. Finally, overexpression of PAK1 in the ApoE-/-Nox1SMCko mice increased vascular elastic fibre degradation, pro-inflammatory cytokine expression and AAA incidence. Therefore, we conclude that Nox1, together with PAK1, facilitates Ang II-induced VSMC activation, vascular inflammation and ECM remodelling, and thus potentiates the AAA formation.

Qianyang Yuyin granules alleviate hypertension-induced vascular remodeling by inhibiting the phenotypic switch of vascular smooth muscle cells

ETHNOPHARMACOLOGICAL RELEVANCE

Qianyang Yuyin granules (QYYY) have been used clinically to treat hypertension for over two decades. Previous clinical trials have shown that QYYY can improve vascular elastic function in hypertensive patients. However, the underlying pharmacological mechanism is unclear.

AIM OF THE STUDY

To elucidate the effects and mechanisms of QYYY on vascular remodeling using a multidisciplinary approach that includes network pharmacology, proteomics, and both in vitro and in vivo experiments.

MATERIALS AND METHODS

The main components of QYYY were identified using ultra-high-performance liquid chromatography and high-resolution mass spectrometry. Network pharmacology and molecular docking were employed to predict QYYY's primary active ingredients, potential therapeutic targets and intervention pathways in hypertensive vascular remodeling. We induced hypertension in male C57BL/6 mice by infusing angiotensin II (Ang II) via osmotic minipumps, and performed pre-treatment with QYYY or Sacubitril/valsartan (Entresto). Blood pressure was monitored in vivo, followed by the extraction of aortas to examine pathological structural changes and alterations in protein expression patterns. The expression and location of proteins involved in the HIF-1α/TWIST1/P-p65 signaling pathway were investigated, as well as markers of vascular smooth muscle cells (VSMCs) phenotypic switch. In vitro, we studied the effects of QYYY water extract on Ang II-stimulated human aortic VSMCs. We investigated whether QYYY could affect the HIF-1α/TWIST1/P-p65 signaling pathway, thereby ameliorating apoptosis, autophagy, and phenotype switch in VSMCs.

RESULTS

We identified 62 main compounds in QYYY, combined with network pharmacology, speculated 827 potentially active substances, and explored 1021 therapeutic targets. The KEGG pathway analysis revealed that the mechanisms of action associated with QYYY therapy potentially encompass various biological processes, including metabolic pathways, TNF signaling pathways, apoptosis, Ras signaling pathways, HIF-1 signaling pathways, autophagy-animal pathways. In hypertensive mice, QYYY restored abnormally elevated blood pressure, vascular remodeling, and inflammation with a dose-response relationship while altering abnormal protein patterns. In vitro, QYYY could inhibit abnormal proliferation, migration, intracellular Ca2+ accumulation and cytoskeletal changes of VSMCs. It improved mitochondrial function, reduced ROS levels, stabilized membrane potential, prevented cell death, and reduced overproduction of TGF-β1, TNF-a, and IL-1β.

CONCLUSION

QYYY may be able to inhibit the overactivation of the HIF-1α/TWIST1/P-p65 signaling pathway, improve the phenotypic switch, and balance apoptosis and autophagy in VSMCs, thereby effectively improving vascular remodeling caused by hypertension.

Inhibition of vascular smooth muscle cell PERK/ATF4 ER stress signaling protects against abdominal aortic aneurysms

Abdominal aortic aneurysms (AAA) are a life-threatening cardiovascular disease for which there is a lack of effective therapy preventing aortic rupture. During AAA formation, pathological vascular remodeling is driven by vascular smooth muscle cell (VSMC) dysfunction and apoptosis, for which the mechanisms regulating loss of VSMCs within the aortic wall remain poorly defined. Using single-cell RNA-Seq of human AAA tissues, we identified increased activation of the endoplasmic reticulum stress response pathway, PERK/eIF2α/ATF4, in aortic VSMCs resulting in upregulation of an apoptotic cellular response. Mechanistically, we reported that aberrant TNF-α activity within the aortic wall induces VSMC ATF4 activation through the PERK endoplasmic reticulum stress response, resulting in progressive apoptosis. In vivo targeted inhibition of the PERK pathway, with VSMC-specific genetic depletion (Eif2ak3fl/fl Myh11-CreERT2) or pharmacological inhibition in the elastase and angiotensin II-induced AAA model preserved VSMC function, decreased elastin fragmentation, attenuated VSMC apoptosis, and markedly reduced AAA expansion. Together, our findings suggest that cell-specific pharmacologic therapy targeting the PERK/eIF2α/ATF4 pathway in VSMCs may be an effective intervention to prevent AAA expansion.

Smooth muscle cell-specific CD47 deletion suppresses atherosclerosis

BACKGROUND

Recent smooth muscle cell (SMC)-lineage tracing and single-cell RNA sequencing (scRNA-seq) experiments revealed a significant role of SMC-derived cells in atherosclerosis development. Further, thrombospondin-1 (TSP1), a matricellular protein, and activation of its receptor cluster of differentiation (CD) 47 have been linked with atherosclerosis. However, the role of vascular SMC TSP1-CD47 signaling in regulating VSMC phenotype and atherogenesis remains unknown.

METHODS

We investigated the role of SMC CD47 activation by TSP1 in regulating VSMC phenotype and atherosclerosis development using various in vitro cell-based assays, molecular biological techniques, immunohistological approaches, reanalysis of publicly available scRNA-seq data, and cell-specific knockout mice.

RESULTS

We observed elevated TSP1 expression in human atherosclerotic vascular tissues and VSMCs. TSP1-treated VSMCs exhibited decreased expression of contractile SMC markers (ACTA2, CNN1, and TAGLN) and increased proliferation. Additional experiments and reanalysis of the scRNA-seq dataset showed CD47 as the major TSP1 receptor in VSMCs, with its expression increased in SMC-derived modulated cells of murine atherosclerotic arteries. Knockdown of CD47 gene in human VSMCs upregulated expression of contractile SMC markers and abrogated TSP1's effects on these genes. SMC-specific Cd47 deletion in mice suppressed atherosclerotic lesion formation, reduced macrophage accumulation, and decreased necrotic area. However, no significant differences were observed in weight gain, liver and adipose tissue mass, plasma total cholesterol, and fasting blood glucose between control and SMC-restricted Cd47-deficient mice. Further experiments demonstrated increased efferocytosis of apoptotic CD47-silenced VSMCs by macrophages.

CONCLUSIONS

These findings suggest that CD47 plays a crucial role in regulating VSMC phenotype, and SMC-specific-Cd47 deletion suppresses atherosclerosis.

NEW AND NOTEWORTHY

VSMC phenotypic switching contributes to atherosclerosis development. The present study reports the novel observations that Cd47 levels are upregulated in phenotypically modulated SMCs within atherosclerotic arteries and targeted deletion of Cd47 specifically in SMCs attenuates atherosclerosis. Mechanistic in vitro investigations further showed that TSP1-CD47 signaling regulates VSMC phenotype. Therefore, targeting SMC CD47 represents a promising therapeutic target to suppress atherogenesis.

Single-cell analysis identifies the CNP/GC-B/cGMP axis as marker and regulator of modulated VSMCs in atherosclerosis

A balanced activity of cGMP signaling contributes to the maintenance of cardiovascular homeostasis. Vascular smooth muscle cells (VSMCs) can generate cGMP via three ligand-activated guanylyl cyclases, the NO-sensitive guanylyl cyclase, the atrial natriuretic peptide (ANP)-activated GC-A, and the C-type natriuretic peptide (CNP)-stimulated GC-B. Here, we study natriuretic peptide signaling in murine VSMCs and atherosclerotic lesions. Correlative profiling of pathway activity and VSMC phenotype at the single-cell level shows that phenotypic modulation of contractile VSMCs to chondrocyte-like plaque cells during atherogenesis is associated with a switch from ANP/GC‑A to CNP/GC‑B signaling. Silencing of the CNP/GC-B axis in VSMCs results in an increase of chondrocyte-like plaque cells. These findings indicate that the CNP/GC-B/cGMP pathway is a marker and atheroprotective regulator of modulated VSMCs, limiting their transition to chondrocyte-like cells. Overall, this study highlights the plasticity of cGMP signaling in VSMCs and suggests analogies between CNP-dependent remodeling of bone and blood vessels.

Dedifferentiation of vascular smooth muscle cells upon vessel injury

Highly differentiated mature vascular smooth muscle cells (VSMCs) are the predominant type of cells constituting arterial walls, which are essential for maintaining the structural and functional integrity of blood vessels. VSMCs demonstrate a notable degree of adaptability following vascular damage, a characteristic that plays a crucial role in the progression of vascular remodeling. Advances in single-cell RNA sequencing in both healthy and pathological vascular tissues have offered profound insights into the complexity of VSMCs, revealing a more intricate diversity than previously recognized. In response to injury, VSMCs undergo dedifferentiation and exhibit pluripotent markers. This review summarizes the researches that have employed lineage tracing alongside single-cell sequencing analysis to explore the dynamics of vascular damage. The primary focus of this study was on the process of dedifferentiation in VSMCs, with particular attention to its underlying mechanisms. The discussion included the impact of microenvironmental cues, the control of transcription factors, and the various molecular pathways involved in VSMCs dedifferentiation. Herein, we provide a comprehensive analysis of cells dedifferentiated from adult VSMCs upon vascular injury.

Reconceptualizing Endothelial-to-mesenchymal transition in atherosclerosis: Signaling pathways and prospective targeting strategies

BACKGROUND

The modification of endothelial cells (ECs) biological function under pathogenic conditions leads to the expression of mesenchymal stromal cells (MSCs) markers, defined as endothelial-to-mesenchymal transition (EndMT). Invisible in onset and slow in progression, atherosclerosis (AS) is a potential contributor to various atherosclerotic cardiovascular diseases (ASCVD). By triggering AS, EndMT, the "initiator" of AS, induces the progression of ASCVD such as coronary atherosclerotic heart disease (CHD) and ischemic cerebrovascular disease (ICD), with serious clinical complications such as myocardial infarction (MI) and stroke. In-depth research of the pathomechanisms of EndMT and identification of potential targeted therapeutic strategies hold considerable research value for the prevention and treatment of ASCVD-associated with delayed EndMT. Although previous studies have progressively unraveled the complexity of EndMT and its pathogenicity triggered by alterations in vascular microenvironmental factors, systematic descriptions of the most recent pathogenic roles of EndMT in the progression of AS, targeted therapeutic strategies, and their future research directions are scarce.

AIM OF REVIEW

We aim to provide new researchers with comprehensive knowledge of EndMT in AS. We exhaustively review the latest research advancements in the field and provide a theoretical basis for investigating EndMT, a biological process with sophisticated mechanisms.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review summarized that altered hemodynamics with microenvironmental crosstalk consisting of inflammatory responses or glycolysis, oxidative stress, lactate or acetyl-CoA (Ac-CoA), fatty acid oxidation (FAO), intracellular iron overload, and transcription factors, including ELK1 and STAT3, modulate the EndMT and affect AS progression. In addition, we provide new paradigms for the development of promising therapeutic agents against these disease-causing processes and indicate promising directions and challenges that need to be addressed to elucidate the EndMT process.

Non-coding RNAs to treat vascular smooth muscle cell dysfunction

Vascular smooth muscle cell (vSMC) dysfunction is a critical contributor to cardiovascular diseases, including atherosclerosis, restenosis and vein graft failure. Recent advances have unveiled a fascinating range of non-coding RNAs (ncRNAs) that play a pivotal role in regulating vSMC function. This review aims to provide an in-depth analysis of the mechanisms underlying vSMC dysfunction and the therapeutic potential of various ncRNAs in mitigating this dysfunction, either preventing or reversing it. We explore the intricate interplay of microRNAs, long-non-coding RNAs and circular RNAs, shedding light on their roles in regulating key signalling pathways associated with vSMC dysfunction. We also discuss the prospects and challenges associated with developing ncRNA-based therapies for this prevalent type of cardiovascular pathology. LINKED ARTICLES: This article is part of a themed issue Non-coding RNA Therapeutics. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v182.2/issuetoc.

Inhibition of Abdominal Aortic Aneurysm Progression Through the CXCL12/CXCR4 Axis via MiR206-3p Sponge

Notably, the C-X-C Motif Chemokine Ligand 12/C-X-C Chemokine Receptor Type 4 (CXCL12/CXCR4) signalling pathway's activation is markedly increased in a mouse model of abdominal aortic aneurysms (AAA). Nonetheless, the precise contribution of this pathway to AAA development remains to be elucidated. The AAA mouse model was induced by local incubation with elastase and oral administration of β-aminopropionitrile. The activity level of the CXCL12/CXCR4 axis was evaluated in both human AAA patients and the mouse model. Smooth muscle cell lineage tracing determined the expression and localisation of CXCR4 in normal aorta and AAA tissue. By transfecting the MiR206-3p sponge to reduce the level of MiR206-3p in AAA, the effects of the CXCL12/CXCR4 pathway on AAA progression as well as the apoptosis and phenotypic transformation of vascular smooth muscle cells (VSMCs) were studied in vivo and in vitro. Single-cell RNA sequencing analysis, serum ELISA, and in vivo experiments indicate a pronounced activation of the CXCL12/CXCR4 axis in both AAA patients and the mouse model. Specific blocking of the CXCL12/CXCR4 axis significantly inhibited further expansion and rupture of the abdominal aorta and reduced the infiltration of inflammatory cells in the aorta and inhibited the phenotypic transformation of contractile VSMCs into a macrophage-like state. Our findings propose that MiR206-3p sponge represents an innovative therapeutic strategy to attenuate AAA progression and rupture risk, primarily through the suppression of the CXCL12/CXCR4 signalling pathway.

Cellular communication network factor 2 regulates smooth muscle cell transdifferentiation and lipid accumulation in atherosclerosis

AIMS

Accruing evidence illustrates an emerging paradigm of dynamic vascular smooth muscle cell (SMC) transdifferentiation during atherosclerosis progression. However, the molecular regulators that govern SMC phenotype diversification remain poorly defined. This study aims to elucidate the functional role and underlying mechanisms of cellular communication network factor 2 (CCN2), a matricellular protein, in regulating SMC plasticity in the context of atherosclerosis.

METHODS AND RESULTS

In both human and murine atherosclerosis, an up-regulation of CCN2 is observed in transdifferentiated SMCs. Using an inducible murine SMC CCN2 deletion model, we demonstrate that SMC-specific CCN2 knockout mice are hypersusceptible to atherosclerosis development as evidenced by a profound increase in lipid-rich plaques along the entire aorta. Single-cell RNA sequencing studies reveal that SMC deficiency of CCN2 positively regulates machinery involved in endoplasmic reticulum stress, endocytosis, and lipid accumulation in transdifferentiated macrophage-like SMCs during the progression of atherosclerosis, findings recapitulated in CCN2-deficient human aortic SMCs.

CONCLUSION

Our studies illuminate an unanticipated protective role of SMC-CCN2 against atherosclerosis. Disruption of vascular wall homeostasis resulting from vascular SMC CCN2 deficiency predisposes mice to atherosclerosis development and progression.

Mesenchymal stem cell therapy in atherosclerosis: A bibliometric and visual analysis

BACKGROUND

Mesenchymal stem cells (MSCs) are capable of self-renewal and differentiation, and extensive studies have demonstrated their therapeutic potential in atherosclerosis (AS).

AIM

To conduct a bibliometric analysis of studies on the use of MSC therapy for AS over the past two decades, assess key trends and provide insights for future research directions.

METHODS

We systematically searched the Web of Science Core Collection database for articles published between 1999 and 2023, yielding a total of 556 articles. Visual representation and bibliometric analysis of information and trends were facilitated using CiteSpace, the R package 'bibliometrix' and VOSviewer.

RESULTS

The analyzed articles were predominantly from 52 countries/regions, with prominent contributions from China and the United States. A cohort of 3057 authors contributed to these publications, with the works of Libby P distinguished by their influence and citation count. Int J Mol Sci has emerged as the journal with the highest publication volume, prominently disseminating influential papers and identifying citation outbreaks. Furthermore, our analysis identified current research hotspots within the field, focusing on vascular progenitor cells, inflammatory mechanisms, and extracellular vesicles. Emerging research frontiers, such as extracellular vesicles and oxidative stress, have been highlighted as areas of burgeoning interest. Finally, we offer perspectives on the status of research and future directions of MSC therapy in AS.

CONCLUSION

This comprehensive analysis provides valuable insights for advancing scientific research on MSC therapy for AS. By elucidating pivotal trends and research directions, this study aimed to foster innovation and promote the progress of disciplines in this field, thereby contributing to advancing scientific knowledge and clinical practice.

Cannabis sativa extracts inhibit LDL oxidation and the formation of foam cells in vitro, acting as potential multi-step inhibitors of atherosclerosis development

Atherosclerotic disease is the leading cause of death world-wide. Our goal was to explore the effect of phytocannabinoids on the molecular mechanisms triggering the development of the atheromatous lesion. Three cannabis sativa extracts of different chemotypes were chemically characterized by UPLC-DAD. The capacity of the extracts to prevent the oxidation of LDL, the formation of foam cells and the activation of an inflammatory response by J774 cells, were monitored by UV-Vis spectrometry, confocal-microscopy and western blot. Three varieties of cannabis sativa, with high (E1), intermediate (E2) and low (E3) THC/CBD ratios were selected. The three cannabis extracts inhibited the oxidation of LDL by copper ions and the formation of foam cells by J774.1 cells challenged with oxLDL (ED50 5-12 μg mL-1). The effect of the cannabinoid extracts on the endocytic process was independent of the canonical cannabinoid receptors, CB1 and CB2, but related to the action of non-canonical receptors (TRPV1, TRPV4 and GPR55), involved in calcium signaling. Decreased levels of CD36 and OLR1 scavenger receptors were, at least partially, responsible for the diminished uptake of oxLDL induced by phytocannabinoids. The downregulation of CD36 and OLR1 could be explained by the observed inhibitory effect of the cannabis extracts on the activation of the NFκB pathway by oxLDL. Phytocannabinoids interfere with the main events leading to the development of the atheromatous plaque, opening new venues on atherosclerosis therapy.

Single-cell analysis identified key macrophage subpopulations associated with atherosclerosis

Background

Atherosclerosis is a lipid-driven inflammatory disease characterized by plaque formation in major arteries. These plaques contain lipid-rich macrophages that accumulate through monocyte recruitment, local macrophage differentiation, and proliferation.

Objective

We identify the macrophage subsets that are closely related to atherosclerosis and reveal the key pathways in the progression of atherosclerotic disease.

Materials and methods

In this study, we characterize the single-cell landscape of atherosclerosis, identifying macrophage subsets closely related to the disease and revealing key pathways in its progression. Using analytical methods like CytoTRACE, Monocle2, Slingshot, and CellChat, we study macrophage differentiation and infer cell trajectory.

Results

The 8,417 macrophages were divided into six subtypes, macrophages: C0 C1QC+ macrophages, C1 SPP1+ macrophages, C2 FCN1+ macrophages, C3 IGKC+ macrophages, C4 FCER1A+ macrophages, C5CALD1+ macrophages. The results of gene set enrichment analysis, Monocle2, and Slingshot suggest that C2 FCN1+ macrophages may play an important role in the progression of atherosclerosis. C2 FCN1+ macrophages interact with endothelial cells via CCL, CXCL, APP, and other pathways to regulate the progression of atherosclerosis.

Conclusion

We identify a key macrophage subgroup (C2 FCN1+ macrophages) associated with atherosclerosis, which interacts with endothelial cells via CCL, CXCL, APP, and other pathways to regulate disease progression.

Insulin receptors in vascular smooth muscle cells regulate plaque stability of atherosclerosis

AIMS

Increased prevalence of acute myocardial infarction related to diabetes and insulin resistance is associated with an elevated risk of unstable atherosclerotic plaques, which are characterized by reduced vascular smooth muscle cells (VSMCs) and extracellular matrix (ECM) and increased inflammation. Thus, insulin resistance may reduce plaque stability, as deleting insulin receptors (IRs) in VSMCs decreases their proliferation and enhances apoptosis.

METHODS AND RESULTS

Direct effects of insulin on VSMCs to alter plaque composition were studied using mice with double knockout of ApoE and IR genes in VSMCs with SMIRKO/ApoE-/-, Myh11-CreERT2EYFP+/ApoE-/-, and Myh11-CreERT2EYFP+IRKO/ApoE-/- mice, which were also used for lineage tracing studies. Compared with ApoE-/- mice, SMIRKO/ApoE-/- mice exhibited more atherosclerotic plaques, which contained less VSMCs and collagen but increased levels of VSMC apoptosis and necrotic areas. Lineage tracing studies showed that Icam1+ Vcam1+ VSMC was inflammatory, which increased in the aortas of Myh11-CreERT2EYFP+IRKO/ApoE-/- mice compared with control mice. Isolated VSMCs lacking IRs expressed higher inflammatory cytokines than cells with IRs. Cell-based studies indicated that insulin's anti-apoptotic and pro-proliferative effects in VSMCs were mediated via activation of the IR/Akt pathway, which were decreased in VSMCs from SMIRKO or high-fat diet mice. An analysis of the IR targets that regulated inflammatory cytokines in VSMCs showed that thrombospondin 1 (Thbs1) and Mmp2 were consistently increased with a loss of IRs. Insulin inhibited Thbs1 expression, but not Mmp2 expression, through p-Akt/p-FoxO1 pathways in VSMCs from ApoE-/- mice, and was impaired in cells from SMIRKO/ApoE-/- mice. Thbs1 further induced Icam1 and Mmp2 expressions in VSMCs.

CONCLUSION

Insulin via IRs has significant actions in VSMCs to decrease inflammation, apoptosis, and ECM turnover via the activation of Akt and FoxO1 pathways. The inhibition of insulin actions and related pathways related to insulin resistance and diabetes may contribute to the formation of unstable atherosclerotic plaques.

Smooth muscle-specific deletion of cellular communication network factor 2 causes severe aorta malformation and atherosclerosis

AIMS

Cellular communication network factor 2 (CCN2) is a matricellular protein implicated in fibrotic diseases, with ongoing clinical trials evaluating anti-CCN2-based therapies. By uncovering CCN2 as abundantly expressed in non-diseased artery tissue, this study aimed to investigate the hypothesis that CCN2 plays a pivotal role in maintaining smooth muscle cell (SMC) phenotype and protection against atherosclerosis.

METHODS AND RESULTS

Global- and SMC-specific Ccn2 knockout mouse models were employed to demonstrate that Ccn2 deficiency leads to SMC de-differentiation, medial thickening, and aorta elongation under normolipidaemic conditions. Inducing hyperlipidaemia in both models resulted in severe aorta malformation and a 17-fold increase in atherosclerosis formation. Lipid-rich lesions developed at sites of the vasculature typically protected from atherosclerosis development by laminar blood flow, covering 90% of aortas and extending to other vessels, including coronary arteries. Evaluation at earlier time points revealed medial lipid accumulation as a lesion-initiating event. Fluorescently labelled LDL injection followed by confocal microscopy showed increased LDL retention in the medial layer of Ccn2 knockout aortas, likely attributed to marked proteoglycan enrichment of the medial extracellular matrix. Analyses leveraging data from the Athero-Express study cohort indicated the relevance of CCN2 in established human lesions, as CCN2 correlated with SMC marker transcripts across 654 transcriptomically profiled carotid plaques. These findings were substantiated through in situ hybridization showing CCN2 expression predominantly in the fibrous cap.

CONCLUSION

This study identifies CCN2 as a major constituent of the normal artery wall, critical in regulating SMC differentiation and aorta integrity and possessing a protective role against atherosclerosis development. These findings underscore the need for further investigation into the potential effects of anti-CCN2-based therapies on the vasculature.

How the bone microenvironment shapes the pre-metastatic niche and metastasis

The bone is a frequent metastatic site, with changes in the mineralized bone and the bone marrow milieu that can also prime other sites for metastasis by educating progenitor cells to support metastatic spread. Stromal and immune populations cooperatively maintain the organizationally complex bone niches and are dysregulated in the presence of a distant primary tumor and metastatic disease. Interrogating the bone niches that facilitate metastatic spread using innovative technologies holds the potential to aid in preventing metastasis in and mediated by the bone. Here, we review recent advances in bone niche biology and its adaptations in the context of cancer.

Chronic inflammation and vascular cell plasticity in atherosclerosis

Vascular smooth muscle cells, endothelial cells and macrophages undergo phenotypic conversions throughout atherosclerosis progression, both as a consequence of chronic inflammation and as subsequent drivers of it. The inflammatory hypothesis of atherosclerosis has been catapulted to the forefront of cardiovascular research as clinical trials have shown that anti-inflammatory therapy reduces adverse cardiovascular events. However, no current therapies have been specifically designed to target the phenotype of plaque cells. Fate mapping has revealed that plaque cells convert to detrimental and beneficial cell phenotypes during atherosclerosis, with cumulative evidence highlighting that vascular cell plasticity is intimately linked with plaque inflammation, ultimately impacting lesion stability. Here we review vascular cell plasticity during atherosclerosis in the context of the chronic inflammatory plaque microenvironment. We highlight the need to better understand how plaque cells behave during therapeutic intervention. We then propose modulating plaque cell phenotype as an unexplored therapeutic paradigm in the clinical setting.

Nanoparticle-based itaconate treatment recapitulates low-cholesterol/low-fat diet-induced atherosclerotic plaque resolution

Current pharmacologic treatments for atherosclerosis do not completely protect patients; additional protection can be achieved by dietary modifications, such as a low-cholesterol/low-fat diet (LCLFD), that mediate plaque stabilization and inflammation reduction. However, this lifestyle modification can be challenging for patients. Unfortunately, incomplete understanding of the underlying mechanisms has thwarted efforts to mimic the protective effects of a LCLFD. Here, we report that the tricarboxylic acid cycle intermediate itaconate (ITA), produced by plaque macrophages, is key to diet-induced plaque resolution. ITA is produced by immunoresponsive gene 1 (IRG1), which we observe is highly elevated in myeloid cells of vulnerable plaques and absent from early or stable plaques in mice and humans. We additionally report development of an ITA-conjugated lipid nanoparticle that accumulates in plaque and bone marrow myeloid cells, epigenetically reduces inflammation via H3K27ac deacetylation, and reproduces the therapeutic effects of LCLFD-induced plaque resolution in multiple atherosclerosis models.

Mechanistic insights into the regression of atherosclerotic plaques

Atherosclerosis is a major contributor to cardiovascular diseases and mortality globally. The progression of atherosclerotic disease results in the expansion of plaques and the development of necrotic cores. Subsequent plaque rupture can lead to thrombosis, occluding blood vessels, and end-organ ischemia with consequential ischemic injury. Atherosclerotic plaques are formed by the accumulation of lipid particles overloaded in the subendothelial layer of blood vessels. Abnormally elevated blood lipid levels and impaired endothelial function are the initial factors leading to atherosclerosis. The atherosclerosis research has never been interrupted, and the previous view was that the pathogenesis of atherosclerosis is an irreversible and chronic process. However, recent studies have found that the progression of atherosclerosis can be halted when patients' blood lipid levels are reversed to normal or lower. A large number of studies indicates that it can inhibit the progression of atherosclerosis lesions and promote the regression of atherosclerotic plaques and necrotic cores by lowering blood lipid levels, improving the repair ability of vascular endothelial cells, promoting the reverse cholesterol transport in plaque foam cells and enhancing the ability of macrophages to phagocytize and clear the necrotic core of plaque. This article reviews the progress of research on the mechanism of atherosclerotic plaque regression. Our goal is to provide guidance for developing better therapeutic approaches to atherosclerosis by reviewing and analyzing the latest scientific findings.

Generation of a novel constitutive smooth muscle cell-specific Myh11 -driven Cre mouse model

Dysfunction in either embryonic or postnatal vascular smooth muscle cells (SMCs) significantly contributes to the progression of various cardiovascular diseases. Therefore, elucidating the molecular mechanisms governing VSMC development and homeostasis is crucial. MYH11 is the most reliable lineage gene for SMCs and has been utilized to develop tamoxifen-inducible Cre driver lines for achieving SMC-specific gene manipulation by crossing with mice carrying the lox P -flanked gene, particularly in adult mice. For studies involving SMCs during embryogenesis, the commonly used constitutive Cre driver is controlled by the Tagln ( Sm22α ) promoter. However, this Cre driver exhibits activity in multiple non-SMC populations, including cardiomyocytes and skeletal muscle precursors, introducing confounding effects. Additionally, most existing SMC-specific Cre drivers are generated using a transgenic approach, raising concerns about random site integration and variable gene copy numbers. To address these limitations, we report a novel Cre mouse model generated by knock-in (KI) of a nuclear-localized Cre recombinase into the Myh11 gene locus using homologous recombination. We confirmed that the Cre activity precisely recapitulates endogenous Myh11 expression by crossing with Rosa26 mTmG or tdTomato reporter mice. Moreover, Myh11 -driven Cre can efficiently delete the floxed allele of the transcription factor Tead1 specifically in SMCs. The Tead1 SMC-specific knockout mice did not exhibit an overt phenotype, thereby circumventing the embryonic lethal phenotype mediated by Tagln -driven Cre, as we previously reported. These findings establish this novel Cre driver line as a robust tool for tracing the Myh11 -positive SMC lineage and manipulating gene function specifically in SMCs during embryonic development in mice.

GWAS breakthroughs: mapping the journey from one locus to 393 significant coronary artery disease associations

Coronary artery disease (CAD) poses a substantial threat to global health, leading to significant morbidity and mortality worldwide. It has a significant genetic component that has been studied through genome-wide association studies (GWAS) over the past 17 years. These studies have made progress with larger sample sizes, diverse ancestral backgrounds, and the discovery of multiple genomic regions related to CAD risk. In this review, we provide a comprehensive overview of CAD GWAS, including information about the genetic makeup of the disease and the importance of ethnic diversity in these studies. We also discuss challenges of identifying causal genes and variants within GWAS loci with a focus on non-coding regions. Additionally, we highlight tissues and cell types relevant to CAD, and discuss clinical implications of GWAS findings including polygenic risk scores, sex-specific differences in CAD genetics, ethnical aspects of personalized interventions, and GWAS guided drug development.

Efferocytosis in atherosclerosis

Cardiovascular disease is the leading cause of death worldwide, and it commonly results from atherosclerotic plaque progression. One of the increasingly recognized drivers of atherosclerosis is dysfunctional efferocytosis, a homeostatic mechanism responsible for the clearance of dead cells and the resolution of inflammation. In atherosclerosis, the capacity of phagocytes to participate in efferocytosis is hampered, leading to the accumulation of apoptotic and necrotic tissue within the plaque, which results in enlargement of the necrotic core, increased luminal stenosis and plaque inflammation, and predisposition to plaque rupture or erosion. In this Review, we describe the different forms of programmed cell death that can occur in the atherosclerotic plaque and highlight the efferocytic machinery that is normally implicated in cardiovascular physiology. We then discuss the mechanisms by which efferocytosis fails in atherosclerosis and other cardiovascular and cardiometabolic diseases, including myocardial infarction and diabetes mellitus, and discuss therapeutic approaches that might reverse this pathological process.

Spatial Transcriptomic Approach to Understanding Coronary Atherosclerotic Plaque Stability

BACKGROUND

Coronary atherosclerotic plaques susceptible to acute coronary syndrome have traditionally been characterized by their surrounding cellular architecture. However, with the advent of intravascular imaging, novel mechanisms of coronary thrombosis have emerged, challenging our contemporary understanding of acute coronary syndrome. These intriguing findings underscore the necessity for a precise molecular definition of plaque stability. Considering this, our study aimed to investigate the vascular microenvironment in patients with stable and unstable plaques using spatial transcriptomics.

METHODS

Autopsy-derived coronary arteries were preserved and categorized by plaque stability (n=5 patients per group). We utilized the GeoMx spatial profiling platform and Whole Transcriptome Atlas to link crucial histological morphology markers in coronary lesions with differential gene expression in specific regions of interest, thereby mapping the vascular transcriptome. This innovative approach allowed us to conduct cell morphological and spatially resolved transcriptional profiling of atherosclerotic plaques while preserving crucial intercellular signaling.

RESULTS

We observed intriguing spatial and cell-specific transcriptional patterns in stable and unstable atherosclerotic plaques, showcasing regional variations within the intima and media. These regions exhibited differential expression of proinflammatory molecules (eg, IFN-γ [interferon-γ], MHC [major histocompatibility complex] class II, proinflammatory cytokines) and prothrombotic signaling pathways. By using lineage tracing through spatial deconvolution of intimal CD68+ (cluster of differentiation 68) cells, we characterized unique, intraplaque subpopulations originating from endothelial, smooth muscle, and myeloid lineages with distinct regional locations associated with plaque instability. In addition, unique transcriptional signatures were observed in vascular smooth muscle and CD68+ cells among plaques exhibiting coronary calcification.

CONCLUSIONS

Our study illuminates distinct cell-specific and regional transcriptional alterations present in unstable plaques. Furthermore, we characterize spatially resolved, in situ evidence supporting cellular transdifferentiation and intraplaque plasticity as significant contributors to plaque instability in human coronary atherosclerosis. Our results provide a powerful resource for the identification of novel mediators of acute coronary syndrome, opening new avenues for preventative and therapeutic treatments.