Mast cells participate in smooth muscle cell reprogramming and atherosclerotic plaque calcification

Challenges and advances in the management of inflammation in atherosclerosis

INTRODUCTION

Atherosclerosis, traditionally considered a lipid-related disease, is now understood as a chronic inflammatory condition with significant global health implications.

OBJECTIVES

This review aims to delve into the complex interactions among immune cells, cytokines, and the inflammatory cascade in atherosclerosis, shedding light on how these elements influence both the initiation and progression of the disease.

METHODS

This review draws on recent clinical research to elucidate the roles of key immune cells, macrophages, T cells, endothelial cells, and clonal hematopoiesis in atherosclerosis development. It focuses on how these cells and process contribute to disease initiation and progression, particularly through inflammation-driven processes that lead to plaque formation and stabilization. Macrophages ingest oxidized low-density lipoprotein (oxLDL), which partially converts to high-density lipoprotein (HDL) or accumulates as lipid droplets, forming foam cells crucial for plaque stability. Additionally, macrophages exhibit diverse phenotypes within plaques, with pro-inflammatory types predominating and others specializing in debris clearance at rupture sites. The involvement of CD4+ T and CD8+ T cells in these processes promotes inflammatory macrophage states, suppresses vascular smooth muscle cell proliferation, and enhances plaque instability.

RESULTS

The nuanced roles of macrophages, T cells, and the related immune cells within the atherosclerotic microenvironment are explored, revealing insights into the cellular and molecular pathways that fuel inflammation. This review also addresses recent advancements in imaging and biomarker technology that enhance our understanding of disease progression. Moreover, it points out the limitations of current treatment and highlights the potential of emerging anti-inflammatory strategies, including clinical trials for agents such as p38MAPK, tumor necrosis factor α (TNF-α), and IL-1β, their preliminary outcomes, and the promising effects of canakinumab, colchicine, and IL-6R antagonists.

CONCLUSION

This review explores cutting-edge anti-inflammatory interventions, their potential efficacy in preventing and alleviating atherosclerosis, and the role of nanotechnology in delivering drugs more effectively and safely.

AQP1 Affects Necroptosis by Targeting RIPK1 in Endothelial Cells of Atherosclerosis

Purpose

Aquaporin 1 (AQP1), a transmembrane water channel protein, has been implicated in the regulation of necroptosis. However, its specific role in atherosclerotic plaque stability through the modulation of necroptosis remains unclear. Therefore, in this study, we aim to investigate whether AQP1 influences necroptosis in atherosclerosis by binding to receptor-interacting serine/threonine-protein kinase 1 (RIPK1) and decreasing the expression of receptor-interacting serine/threonine-protein kinase 3 (RIPK3) and mixed lineage kinase domain-like pseudokinase (MLKL).

Patients and Methods

The gene expression of AQP1 and necroptosis-associated genes significantly differ between atherosclerosis and normal groups. Genes linked to necroptosis were screened to influence the AS identified by weighted gene coexpression network analysis (WGCNA). Then we collected femoral atherosclerosis and normal aortic samples, further conducted single-cell sequencing and spatial transcriptomic methods to confirm the potential function and pathway of AQP1 in endothelial cells. Meanwhile, we overexpressed AQP1 in ox-LDL-treated endothelial cells in vitro.

Results

Firstly, via single-sample Gene Set Enrichment Analysis (ssGSEA) scores, we found that necroptosis plays the most important role among all ways of programmed cell death in two kinds of atherosclerosis. AQP1, RIPK1, RIPK3 and MLKL express differently in normal and atherosclerosis tissue by differentially expressed gene (DEG) analysis and Western Blot (WB). WGCNA analysis indicates that AQP1, MLKL and RIPK3 were significantly related to the AS. The area under the curve of the above hub genes was greater than 0.8 (AQP1 0.946, RIPK1 0.908, RIPK3 0.988, MLKL 0.863). We found AQP1 highly enriched in endothelial cells (ECs) by single-cell analysis. We sequenced the samples by spatial transcriptome and found that AQP1 was also mainly enriched in ECs both in expression and spatial location. With AQP1 overexpression in ECs, it significantly inhibited the expression of MLKL and RIPK3 and stimulated EC proliferation.

Conclusion

Our study identified that AQP1 suppresses atherosclerotic necroptosis by inhibiting the expression of RIPK3 and MLKL in ECs which might indicates that AQP1 plays a role in atherosclerosis. This new mechanism contributes to improving the diagnostic, prognostic, and therapeutic outcomes of atherosclerosis.

CPP-calcification of articular cartilage is associated with elevated cytokine levels in synovial fluid

Background

Calcification of articular tissues is commonly observed in later osteoarthritis (OA) stages and can be caused by basic calcium phosphate (BCP) or calcium pyrophosphate (CPP) crystals. Calcification, particularly CPP deposition, has recently been associated with inflammation and cellular senescence. Investigating this association, we analyzed the concentration of various inflammatory mediators in synovial fluid and synovial membrane of OA patients in relation to calcification and the different crystal types.

Methods

Synovial fluid was collected from OA patients during joint replacement surgery. Cytokine concentrations were measured using magnetic bead-based multiplex assay using Luminex® technology. Radiographs were used to determine and grade calcification of the knee joint and involved calcium crystal types were identified via Raman spectroscopy.

Results

Synovial fluid of patients with radiological calcification showed elevated levels of multiple cytokines (IL-10, IL-15, IL-1ra, GM-CSF), chemokines (IL-8, MCP-1, MIP-1b) and growth factors (PDGF-AB/BB, VEGF). Crystal differentiation revealed higher synovial fluid concentrations of IL-15, IL-1ra, IL-10, GM-CSF, PDGF-AB/BB and MIP-1b in patients with CPP- compared to BCP-calcified cartilage.

Conclusion

We show an elevated cytokine profile in synovial fluid of patients with radiological calcification that may be linked to CPP depositison in cartilage.

Cellular and Molecular Mechanisms of Mast Cells in Atherosclerotic Plaque Progression and Destabilization

Mast cells (MCs) are commonly recognized for their crucial involvement in the pathogenesis of allergic diseases, but over time, it has come to light that they also play a role in the pathophysiology of non-allergic disorders including atherosclerosis. The involvement of MCs in the pathology of atherosclerosis is supported by their accumulation in atherosclerotic plaques upon their progression and the association of intraplaque MC numbers with acute cardiovascular events. MCs that accumulate within the atherosclerotic plaque release a cocktail of mediators through which they contribute to neovascularization, plaque progression, instability, erosion, rupture, and thrombosis. At a molecular level, MC-released proteases, especially cathepsin G, degrade low-density lipoproteins (LDL) and mediate LDL fusion and binding of LDL to proteoglycans (PGs). Through a complicated network of chemokines including CXCL1, MCs promote the recruitment of among others CXCR2+ neutrophils, therefore, aggravating the inflammation of the plaque environment. Additionally, MCs produce extracellular traps which worsen inflammation and contribute to atherothrombosis. Altogether, evidence suggests that MCs actively, via several underlying mechanisms, contribute to atherosclerotic plaque destabilization and acute cardiovascular syndromes, thus, making the study of interventions to modulate MC activation an interesting target for cardiovascular medicine.

Recent Advances of Using Exosomes as Diagnostic Markers and Targeting Carriers for Cardiovascular Disease

Cardiovascular diseases (CVDs) are the leading cause of human death worldwide. Exosomes act as endogenous biological vectors; they possess advantages of low immunogenicity and low safety risks, also providing tissue selectivity, including the inherent targeting the to heart. Therefore, exosomes not only have been applied as biomarkers for diagnosis and therapeutic outcome confirmation but also showed potential as drug carriers for cardiovascular targeting delivery. This review aims to summarize the progress and challenges of exosomes as novel biomarkers, especially many novel exosomal noncoding RNAs (ncRNAs), and also provides an overview of the improved targeting functions of exosomes by unique engineered approaches, the latest developed administration methods, and the therapeutic effects of exosomes used as the biocarriers of medications for cardiovascular disease treatment. Also, the possible therapeutic mechanisms and the potentials for transferring exosomes to the clinic for CVD treatment are discussed. The advances, in vivo and in vitro applications, modifications, mechanisms, and challenges summarized in this review will provide a general understanding of this promising strategy for CVD treatment.

Targeting gut microbiota and immune crosstalk: potential mechanisms of natural products in the treatment of atherosclerosis

Atherosclerosis (AS) is a chronic inflammatory reaction that primarily affects large and medium-sized arteries. It is a major cause of cardiovascular disease and peripheral arterial occlusive disease. The pathogenesis of AS involves specific structural and functional alterations in various populations of vascular cells at different stages of the disease. The immune response is involved throughout the entire developmental stage of AS, and targeting immune cells presents a promising avenue for its treatment. Over the past 2 decades, studies have shown that gut microbiota (GM) and its metabolites, such as trimethylamine-N-oxide, have a significant impact on the progression of AS. Interestingly, it has also been reported that there are complex mechanisms of action between GM and their metabolites, immune responses, and natural products that can have an impact on AS. GM and its metabolites regulate the functional expression of immune cells and have potential impacts on AS. Natural products have a wide range of health properties, and researchers are increasingly focusing on their role in AS. Now, there is compelling evidence that natural products provide an alternative approach to improving immune function in the AS microenvironment by modulating the GM. Natural product metabolites such as resveratrol, berberine, curcumin, and quercetin may improve the intestinal microenvironment by modulating the relative abundance of GM, which in turn influences the accumulation of GM metabolites. Natural products can delay the progression of AS by regulating the metabolism of GM, inhibiting the migration of monocytes and macrophages, promoting the polarization of the M2 phenotype of macrophages, down-regulating the level of inflammatory factors, regulating the balance of Treg/Th17, and inhibiting the formation of foam cells. Based on the above, we describe recent advances in the use of natural products that target GM and immune cells crosstalk to treat AS, which may bring some insights to guide the treatment of AS.