Molecular Interactions Between Vascular Smooth Muscle Cells and Macrophages in Atherosclerosis

Modeling Foam Cell Formation in A Hydrogel-Based 3D-Intimal Model: A Study of The Role of Multi-Diseases During Early Atherosclerosis

Monocyte recruitment and transmigration are crucial in atherosclerotic plaque development. The multi-disease complexities aggravate the situation and continue to be a constant concern for understanding atherosclerosis plaque development. Herein, a 3D hydrogel-based model that integrates disease-induced microenvironments is sought to be designed, allowing us to explore the early stages of atherosclerosis, specifically examining monocyte fate in multi-disease complexities. As a proof-of-concept study, murine cells are employed to develop the model. The model is constructed with collagen embedded with murine aortic smooth muscle cells and a murine endothelial monolayer lining. The model achieves in vitro disease complexities using external stimuli such as glucose and lipopolysaccharide (LPS). Hyperglycemia exhibits a significant increase in monocyte adhesion but no enhancement in monocyte transmigration and foam cell conversion compared to euglycemia. Chronic infection achieved by LPS stimulation results in a remarkable augment in initial monocyte attachment and a significant increment in monocyte transmigration and foam cells in all concentrations. Moreover, the model exhibits synergistic sensitivity under multi-disease conditions such as hyperglycemia and infection, enhancing initial monocyte attachment, cell transmigration, and foam cell formation. Additionally, western blot data prove the enhanced levels of inflammatory biomarkers, indicating the model's capability to mimic disease-induced complexities during early atherosclerosis progression.

Role of dysregulated macrophage subpopulation ratios and functional changes in the development of coronary atherosclerosis

Coronary heart disease is one of the most significant risk factors affecting human health worldwide. Its pathogenesis is intricate, with atherosclerosis being widely regarded as the leading cause. Aberrant lipid metabolism in macrophages is recognized as one of the triggering factors in atherosclerosis development. To investigate the role of macrophages in the formation of coronary artery atherosclerosis, we utilized single-cell data from wild-type mice obtained from the aortic roots and ascending aortas after long-term high-fat diet feeding, as deposited in GSE131776. Seurat software was employed to refine the single-cell data in terms of scale and cell types, facilitating the identification of differentially expressed genes. Through the application of differential expression genes, we conducted Gene Ontology and Kyoto Encyclopedia of Genes and Genomes functional enrichment analyses at 0, 8 and 16 weeks, aiming to uncover pathways with the most pronounced functional alterations as the high-fat diet progressed. The AddModuleScore function was employed to score the expression of these pathways across different cell types. Subsequently, macrophages were isolated and further subdivided into subtypes, followed by an investigation into intercellular communication within these subtypes. Subsequent to this, we induced THP-1 cells to generate foam cells, validating critical genes identified in prior studies. The results revealed that macrophages underwent the most substantial functional changes as the high-fat diet progressed. Furthermore, two clusters were identified as potentially playing pivotal roles in macrophage functional regulation during high-fat diet progression. Additionally, macrophage subtypes displayed intricate functionalities, with mutual functional counterbalances observed among these subtypes. The proportions of macrophage subtypes and the modulation of anti-inflammatory and pro-inflammatory functions played significant roles in the development of coronary artery atherosclerosis.

The Impact of Modern Anti-Diabetic Treatment on Endothelial Progenitor Cells

Diabetes is one of the leading chronic diseases globally with a significant impact on mortality. This condition is associated with chronic microvascular and macrovascular complications caused by vascular damage. Recently, endothelial progenitor cells (EPCs) raised interest due to their regenerative properties. EPCs are mononuclear cells that are derived from different tissues. Circulating EPCs contribute to regenerating the vessel's intima and restoring vascular function. The ability of EPCs to repair vascular damage depends on their number and functionality. Diabetic patients have a decreased circulating EPC count and impaired EPC function. This may at least partially explain the increased risk of diabetic complications, including the increased cardiovascular risk in these patients. Recent studies have confirmed that many currently available drugs with proven cardiovascular benefits have beneficial effects on EPC count and function. Among these drugs are also medications used to treat different types of diabetes. This manuscript aims to critically review currently available evidence about the ways anti-diabetic treatment affects EPC biology and to provide a broader context considering cardiovascular complications. The therapies that will be discussed include lifestyle adjustments, metformin, sulphonylureas, gut glucosidase inhibitors, thiazolidinediones, dipeptidyl peptidase 4 inhibitors, glucagon-like peptide 1 receptor analogs, sodium-glucose transporter 2 inhibitors, and insulin.

LncRNAs as Regulators of Atherosclerotic Plaque Stability

Current clinical data show that, despite constant efforts to develop novel therapies and clinical approaches, atherosclerotic cardiovascular diseases (ASCVD) are still one of the leading causes of death worldwide. Advanced and unstable atherosclerotic plaques most often trigger acute coronary events that can lead to fatal outcomes. However, despite the fact that different plaque phenotypes may require different treatments, current approaches to prognosis, diagnosis, and classification of acute coronary syndrome do not consider the diversity of plaque phenotypes. Long non-coding RNAs (lncRNAs) represent an important class of molecules that are implicated in epigenetic control of numerous cellular processes. Here we review the latest knowledge about lncRNAs' influence on plaque development and stability through regulation of immune response, lipid metabolism, extracellular matrix remodelling, endothelial cell function, and vascular smooth muscle function, with special emphasis on pro-atherogenic and anti-atherogenic lncRNA functions. In addition, we present current challenges in the research of lncRNAs' role in atherosclerosis and translation of the findings from animal models to humans. Finally, we present the directions for future lncRNA-oriented research, which may ultimately result in patient-oriented therapeutic strategies for ASCVD.

Possible molecular mechanisms underlying the development of atherosclerosis in cancer survivors

Cancer survivors undergone treatment face an increased risk of developing atherosclerotic cardiovascular disease (CVD), yet the underlying mechanisms remain elusive. Recent studies have revealed that chemotherapy can drive senescent cancer cells to acquire a proliferative phenotype known as senescence-associated stemness (SAS). These SAS cells exhibit enhanced growth and resistance to cancer treatment, thereby contributing to disease progression. Endothelial cell (EC) senescence has been implicated in atherosclerosis and cancer, including among cancer survivors. Treatment modalities for cancer can induce EC senescence, leading to the development of SAS phenotype and subsequent atherosclerosis in cancer survivors. Consequently, targeting senescent ECs displaying the SAS phenotype hold promise as a therapeutic approach for managing atherosclerotic CVD in this population. This review aims to provide a mechanistic understanding of SAS induction in ECs and its contribution to atherosclerosis among cancer survivors. We delve into the mechanisms underlying EC senescence in response to disturbed flow and ionizing radiation, which play pivotal role in atherosclerosis and cancer. Key pathways, including p90RSK/TERF2IP, TGFβR1/SMAD, and BH4 signaling are explored as potential targets for cancer treatment. By comprehending the similarities and distinctions between different types of senescence and the associated pathways, we can pave the way for targeted interventions aim at enhancing the cardiovascular health of this vulnerable population. The insights gained from this review may facilitate the development of novel therapeutic strategies for managing atherosclerotic CVD in cancer survivors.

CircRnas in atherosclerosis, with special emphasis on the spongy effect of circRnas on miRnas

Atherosclerosis (AS) is a chronic inflammatory disease, which leads to atherosclerotic rupture, lumen stenosis and thrombosis, and often endangers life. Circular RNAs (circRNAs) are a special class of non-coding RNA molecules, whose abnormal expression has been proved to be closely related to human diseases, including AS. Both the abnormal regulation of circRNAs and the sponging effect on miRNAs would lead to changes in gene expression in the form of epigenetic modification, ultimately leading to the formation of AS. CircRNAs can be used as peripheral blood markers of AS, and play an important regulatory role in the proliferation, migration, inflammation and apoptosis of vascular smooth muscle cells, endothelial cells and macrophage, which are key cells for the development of AS. The in-depth understanding of circRNAs in AS not only provides a new method for the diagnosis of AS, but also provides a new idea for the treatment of AS.

Introducing Circulating Vasculature-Related Transcripts as Biomarkers in Coronary Artery Disease

BACKGROUND

Atherosclerotic plaque is considered the hallmark of atherosclerotic lesions in coronary atherosclerosis (CAS), the primary pathogenesis in coronary artery disease (CAD), which develops and progresses through a complex interplay between immune cells, vascular cells, and endothelial shear stresses. Early diagnosis of CAS is critical for avoiding plaque rupture and sudden death. Therefore, identifying new CAD biomarkers linked to vessel wall functions, such as RNA molecules with their distinct signature, is a promising development for these patients. With this rationale, the present study investigated the expression level of the vascular-related RNA transcripts (lncRNA ANRIL, miRNA-126-5p, CDK4, CDK6, TGF-β, E-cadherin, and TNF-α) implicated in the cellular vascular function, proliferation, and inflammatory processes.

METHODS

A case-control study design with a total of 180 subjects classified participants into two groups; CAD and control groups. The relative expression levels of the seven transcripts under study-selected using online bioinformatics tools and current literature-were assessed in the plasma of all study participants using RT-qPCR. Their predictive significance testing, scoring of disease prioritization, enrichment analysis, and the miRNA-mRNA regulatory network was investigated.

RESULTS

The relative expression levels of all seven of the circulating vascular-related transcripts under study were statistically significant between CAD patients and controls. Receiver operating characteristic (ROC) analysis results indicated the statistical significance of all the transcripts under study with CDK4 showing the highest area under the curve (AUC) equivalent to 0.91, followed by E-cadherin (0.90), miRNA-126-5p (0.83), ANRIL (0.82), TNF-α (0.63), TGF-β (0.62), and CDK6 (0.59), in descending order. A strong association was detected between most of the transcripts studied in CAD patients with a significant Spearman's correlation coefficient with a two-tailed significance of p < 0.001. Network analysis revealed a strong relationship between the five circulating vasculature transcripts studied and their target miRNAs and miR-126-5p, but not for ANRIL.

CONCLUSION

The seven circulating vascular-related RNA transcripts under study could serve as potential CAD biomarkers, reflecting the cellular vascular function, proliferation, and inflammatory processes in CAD patients. Therefore, blood transcriptome analysis opens new frontiers for the non-invasive diagnosis of CAD.

Mitochondrial dynamics in vascular remodeling and target-organ damage

Vascular remodeling is the pathological basis for the development of many cardiovascular diseases. The mechanisms underlying endothelial cell dysfunction, smooth muscle cell phenotypic switching, fibroblast activation, and inflammatory macrophage differentiation during vascular remodeling remain elusive. Mitochondria are highly dynamic organelles. Recent studies showed that mitochondrial fusion and fission play crucial roles in vascular remodeling and that the delicate balance of fusion-fission may be more important than individual processes. In addition, vascular remodeling may also lead to target-organ damage by interfering with the blood supply to major body organs such as the heart, brain, and kidney. The protective effect of mitochondrial dynamics modulators on target-organs has been demonstrated in numerous studies, but whether they can be used for the treatment of related cardiovascular diseases needs to be verified in future clinical studies. Herein, we summarize recent advances regarding mitochondrial dynamics in multiple cells involved in vascular remodeling and associated target-organ damage.

Single-cell transcriptomic, transcriptomic, and metabolomic characterization of human atherosclerosis

Background

Atherosclerosis is the main cause of many cardiovascular and cerebrovascular diseases (CVDs), and gaining a deeper understanding of the intercellular connections and key central genes which mediate formation of atherosclerotic plaques is required.

Methods

We performed a comprehensive bioinformatics analysis of differential genetic screening, Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathway annotation, protein-protein interactions (PPIs), pseudo-timing, intercellular communication, transcription factors on carotid single-cell sequencing data, and aortic bulk transcriptome and metabolomic data.

Results

Ten cell types were identified in the data: T cells, monocytes, smooth muscle cells, endothelial cells, B cells, fibroblasts, plasma cells, mast cells, dendritic cells, and natural killer cells. Endothelial, fibroblast, macrophage, and smooth muscle cell subtype differentiation trajectories, interaction networks, and important transcription factors were characterized in detail. Finally, using this information combined with transcriptome and metabolome analyses, we found the key genes and signaling pathways of atherosclerosis, especially the advanced glycation end products and receptor for advanced glycation end products signaling pathway (AGE-RAGE signaling pathway) in diabetic complications, linked the differential metabolites with fibroblasts and atherosclerosis and contributed to it in patients with diabetes.

Conclusions

Collectively, this study provides key genes, signaling pathways, cellular communication, and transcription factors among endothelial cells, fibroblasts, macrophages, and smooth muscle cells for the study of atherosclerotic plaques, and provides a basis for the diagnosis and treatment of atherosclerosis-like sclerosis.

Smooth Muscle Cell—Macrophage Interactions Leading to Foam Cell Formation in Atherosclerosis: Location, Location, Location

Cholesterol-overloaded cells or “foam cells” in the artery wall are the biochemical hallmark of atherosclerosis, and are responsible for much of the growth, inflammation and susceptibility to rupture of atherosclerotic lesions. While it has previously been thought that macrophages are the main contributor to the foam cell population, recent evidence indicates arterial smooth muscle cells (SMCs) are the source of the majority of foam cells in both human and murine atherosclerosis. This review outlines the timeline, site of appearance and proximity of SMCs and macrophages with lipids in human and mouse atherosclerosis, and likely interactions between SMCs and macrophages that promote foam cell formation and removal by both cell types. An understanding of these SMC-macrophage interactions in foam cell formation and regression is expected to provide new therapeutic targets to reduce the burden of atherosclerosis for the prevention of coronary heart disease, stroke and peripheral vascular disease.

Coagulation Factor XIII Val34Leu Polymorphism in the Prediction of Premature Cardiovascular Events-The Results of Two Meta-Analyses

Background: Polymorphisms within the gene that encodes for coagulation factor XIII (FXIII) have been suggested to be involved in the pathogeneses of ischemic stroke (IS) and myocardial infarction (MI). The Val34Leu polymorphism is one of the most commonly analysed FXIII polymorphisms. However, studies on the role of the Val34Leu polymorphism in the aetiology of vascular diseases often show contradictory results. In the present meta-analysis, we aimed to pool data from available articles to assess the relationship between the FXIII Val34Leu polymorphism and the susceptibilities to IS of undetermined source and premature MI in patients aged below 55 years. Methods: We searched databases (PubMed, Embase, Google Scholar, SciELO, and Medline) using specific keywords (the last search was in January 2022). Eventually, 18 studies (627 cases and 1639 controls for IS; 2595 cases and 4255 controls for MI) met the inclusion criteria. Data were analysed using RevMan 5.4 and StatsDirect 3 link software. The relation between Val34Leu polymorphism and disease was analysed in five genetic models, i.e., dominant, recessive, additive, heterozygous, and allelic. Results: No relation between Val34Leu polymorphism and IS in young adults was observed in all analysed genetic models. For premature MI, significant pooled OR was found between the carrier state of the Leu allele (Val/Leu + Leu/Leu vs. Val/Val) and a lack of MI, suggesting its protective role (OR = 0.80 95%CI 0.64–0.99, p = 0.04). A similar finding was observed for the heterozygous model in MI (Val/Leu vs. Val/Val) (OR = 0.77 95%CI 0.61–0.98, p = 0.03). No relation was found for the recessive, additive, and allelic models in MI. Conclusions: In the population of young adults, no positive correlation was found between the FXIII Val34Leu polymorphism and IS of undetermined source in any of the analysed genetic models. In turn, the carrier state of the 34Leu allele as well as FXIII heterozygotes themselves were found to play a protective role in relation to premature MI.

The Immunomodulatory Effects of Statins on Macrophages

Statins are 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors used worldwide to manage dyslipidaemia and thus limit the development of atherosclerotic disease and its complications. These atheroprotective drugs are now known to exert pleiotropic actions outside of their cholesterol-lowering activity, including altering immune cell function. Macrophages are phagocytic leukocytes that play critical functional roles in the pathogenesis of atherosclerosis and are directly targeted by statins. Early studies documented the anti-inflammatory effects of statins on macrophages, but emerging evidence suggests that these drugs can also enhance pro-inflammatory macrophage responses, creating an unresolved paradox. This review comprehensively examines the in vitro, in vivo, and clinical literature to document the statin-induced changes in macrophage polarization and immunomodulatory functions, explore the underlying mechanisms involved, and offer potential explanations for this paradox. A better understanding of the immunomodulatory actions of statins on macrophages should pave the way for the development of novel therapeutic approaches to manage atherosclerosis and other chronic diseases and conditions characterised by unresolved inflammation.