Metalloproteinases in atherosclerosis

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.

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.

PM2.5 Induces the Instability of Atherosclerotic Plaques by Activating the Notch Signaling Pathway In Vivo and In Vitro

Fine particulate matter (PM2.5) can exacerbate the instability of atherosclerotic plaques although the exact chemical process driving atherosclerosis remains unknown. In order to create atherosclerotic models, a high-fat diet and vitamin D3 injections were given to 56 Wistar rats in this investigation. The atherosclerotic rats were split into four groups at random and given different doses of PM2.5 (0, 1.5, 7.5, and 37.5 mg/kg) for 4 weeks. To investigate the mechanism, foam cells were exposed to PM2.5 (0, 25, 50, and 100 μg/mL) for 24 h. The results showed that PM2.5 exposure caused collagen fibers thinner and muscle fibers were disorganized. PM2.5 exposure significantly affected the expression of MMP2, MMP9, TIMP2, and vimentin in aortas of atherosclerotic rats. Moreover, PM2.5 exposure increased the expression of the Notch signaling pathways which was correlated with the expression of atherosclerotic plaque stability-related genes. PM2.5 exposure also increased the apoptosis rate of foam cells. The expression of MMP2, MMP9, and vimentin was increased and TIMP2 was decreased with the increasing PM2.5 dose in foam cells. The inhibition of the Notch signaling pathway can alleviate the alteration of atherosclerotic plaque stability-related genes. The findings demonstrated that PM2.5 exposure can cause atherosclerotic plaques to become unstable, aggravating the progression of atherosclerosis, a process in which the Notch signaling pathway is crucial.

Recent Advances in Micro/Nanomotor for the Therapy and Diagnosis of Atherosclerosis

Atherosclerotic cardiovascular disease poses a significant global public health threat with a high incidence that can result in severe mortality and disability. The lack of targeted effects from traditional therapeutic drugs on atherosclerosis may cause damage to other organs and tissues, necessitating the need for a more focused approach to address this dilemma. Micro/nanomotors are self-propelled micro/nanoscale devices capable of converting external energy into autonomous movement, which offers advantages in enhancing penetration depth and retention while increasing contact area with abnormal sites, such as atherosclerotic plaque, inflammation, and thrombosis, within blood vessel walls. Recent studies have demonstrated the crucial role micro/nanomotors play in treating atherosclerotic cardiovascular disease. Hence, this review highlights the recent progress of micro/nanomotor technology in atherosclerotic cardiovascular disease, including the effective promotion of micro/nanomotors in the circulatory system, overcoming hemorheological barriers, targeting the atherosclerotic plaque microenvironment, and targeting intracellular drug delivery, to facilitate atherosclerotic plaque localization and therapy. Furthermore, we also describe the potential application of micro/nanomotors in the imaging of vulnerable plaque. Finally, we discuss key challenges and prospects for treating atherosclerotic cardiovascular disease while emphasizing the importance of designing individualized management strategies specific to its causes and microenvironmental factors.

Emerging Anti-Inflammatory COPD Treatments: Potential Cardiovascular Impacts

Chronic obstructive pulmonary disease (COPD) is a progressive inflammatory condition often complicated by cardiovascular disease (CVD) due to shared inflammatory pathways. This review explores the cardiovascular impacts of emerging anti-inflammatory therapies in COPD. Phosphodiesterase (PDE) inhibitors may offer anti-inflammatory effects with improved lung function but pose potential risks for arrhythmias when PDE3 is inhibited although PDE4 inhibitors reduce cardiovascular events by improving endothelial function and reducing thrombosis. Similarly, p38 mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K) inhibitors target COPD-related inflammation and may benefit COPD patients with CVD. p38 MAPK inhibitors reduce cardiac fibrosis, enhance contractility and lower the risk of arrhythmia. PI3K inhibitors target the PI3K/Akt pathway, which drives atherosclerosis and cardiac fibrosis, and thus potentially mitigate both plaque instability and fibrosis. Biologic therapies, including monoclonal antibodies that inhibit IL-5, IL-13/IL-4, thymic stromal lymphopoietin, IL-33, and IL-17A, show promise in reducing exacerbations but require close cardiovascular monitoring due to their immunomodulatory effects. Single-target inhibitors of neutrophil elastase or matrix metalloproteinases show limited efficacy in COPD but may aid cardiovascular patients by stabilizing atherosclerotic plaques through promoting vascular smooth muscle cell proliferation. However, their tendency to degrade the extracellular matrix and attract immune cells may heighten plaque rupture risk, contraindicating use in CVD. Alpha-1 antitrypsin replacement therapy holds promise, potentially reducing COPD exacerbations and providing cardiovascular protection, especially in myocardial injury. Understanding the influence of these innovative therapies on CVD is vital, making it imperative to examine these molecules in COPD patients with CVD at an early stage.

Vascular Extracellular Matrix in Atherosclerosis

The extracellular matrix (ECM) plays a central role in the structural integrity and functionality of the cardiovascular system. Moreover, the ECM is involved in atherosclerotic plaque formation and stability. In fact, ECM remodeling affects plaque stability, cellular migration, and inflammatory responses. Collagens, fibronectin, laminin, elastin, and proteoglycans are crucial proteins during atherosclerosis development. This dynamic remodeling is driven by proteolytic enzymes such as matrix metalloproteinases (MMPs), cathepsins, and serine proteases. Exploring and investigating ECM dynamics is an important step to designing innovative therapeutic strategies targeting ECM remodeling mechanisms, thus offering significant advantages in the management of cardiovascular diseases. This review illustrates the structure and role of vascular ECM, presenting a new perspective on ECM remodeling and its potential as a therapeutic target in atherosclerosis treatments.

The Anti-Inflammatory Effect of Lactococcus lactis-Ling-Zhi 8 on Ameliorating Atherosclerosis and Nonalcoholic Fatty Liver in High-Fat Diet Rabbits

Inflammation plays a crucial role in atherosclerosis and nonalcoholic fatty liver disease (NAFLD). We previously engineered a recombinant Lactococcus lactis strain expressing the Ling-Zhi immunomodulatory protein (L. lactis-LZ8). This study investigated the anti-atherosclerotic effects of L. lactis-LZ8 in rabbits fed a high-fat diet (HFD). Changes in body weight, serum lipid profiles, and liver function were monitored. The aorta and liver tissues were analyzed for gross pathology and histopathology. Eight-week administration of L. lactis-LZ8 with HFD ameliorated atherosclerosis by downregulating protein and gene expression associated with lipid metabolism and inflammation in the aortas. The rabbits receiving L. lactis-LZ8 exhibited a significant dose-dependent reduction in hepatic fat accumulation. RNA sequencing of the livers revealed that inflammatory genes in the L. lactis-LZ8 groups were downregulated compared to the HFD group. Disease ontology enrichment analysis indicated that these genes were involved in atherosclerosis. Gene set enrichment analysis plots revealed significant enrichment in the gene sets related to cholesterol homeostasis. CIBERSORT immune cell fraction analysis indicated significant infiltration by regulatory T cells, CD8+ T cells, activated dendritic cells, and natural killer cells in the L. lactis-LZ8 group. Our studies underscore LZ8's role in precision nutrition, providing a potential solution to the current challenges in modifying atherosclerosis and NAFLD.

Extracellular Vesicles as Mediators in Atherosclerotic Cardiovascular Disease

Atherosclerosis is a chronic inflammatory disease of the arterial intima, characterized by accumulation of lipoproteins and accompanying inflammation, leading to the formation of plaques that eventually trigger occlusive thrombotic events, such as myocardial infarction and ischemic stroke. Although many aspects of plaque development have been elucidated, the role of extracellular vesicles (EVs), which are lipid bilayer-delimited vesicles released by cells as mediators of intercellular communication, has only recently come into focus of atherosclerosis research. EVs comprise several subtypes that may be differentiated by their size, mode of biogenesis, or surface marker expression and cargo. The functional effects of EVs in atherosclerosis depend on their cellular origin and the specific pathophysiological context. EVs have been suggested to play a role in all stages of plaque formation. In this review, we highlight the known mechanisms by which EVs modulate atherogenesis and outline current limitations and challenges in the field.

ECM Microenvironment in Vascular Homeostasis: New Targets for Atherosclerosis

Alterations in vascular extracellular matrix (ECM) components, interactions, and mechanical properties influence both the formation and stability of atherosclerotic plaques. This review discusses the contribution of the ECM microenvironment in vascular homeostasis and remodeling in atherosclerosis, highlighting Cartilage oligomeric matrix protein (COMP) and its degrading enzyme ADAMTS7 as examples, and proposes potential avenues for future research aimed at identifying novel therapeutic targets for atherosclerosis based on the ECM microenvironment.

Short-Term Atorvastatin Therapy in Healthy Individuals Results in Unaltered Plasma MMP Levels and Disrupted MMP-7 Correlation with Blood Lipids and Blood Count-Derived Inflammatory Markers

Background: Matrix metalloproteinases (MMPs) play an important role in the pathophysiology of atherosclerosis. Reportedly, statins can decrease MMP activity in patients with atherosclerotic cardiovascular disease, but this effect has not been studied in healthy individuals. Methods: MMPs 2, 7, and 9 and several other parameters were measured before and after a four-week course of moderate-dose atorvastatin (20 mg/day) in 21 healthy individuals. Results: Atorvastatin treatment resulted in lower total cholesterol, LDL-cholesterol, non-HDL-cholesterol, and triglycerides (p < 0.001 for all), but higher levels of plasma enzymes AST, ALT, CK, and LDH (p < 0.05 for all). No effect of atorvastatin on plasma MMP median concentrations was recorded. Before treatment, moderate positive significant correlations were found between MMP-7 and age, blood lipids, and blood count-derived inflammatory markers. Pre-treatment MMP-7 was best predicted by the total cholesterol-to-HDL cholesterol ratio in a remnant cholesterol-weighted least squares regression model. After atorvastatin treatment, MMP-7 no longer correlated with these markers. Conclusions: While the effect of statins on plasma MMPs in atherosclerosis is controversial, short-term moderate-dose atorvastatin treatment does not seem to affect levels of MMPs 2, 7, and 9 in healthy individuals. However, an intriguing correlation between MMP-7 and atherosclerosis-related blood lipids and neutrophil-associated inflammatory biomarkers seems to be disrupted by atorvastatin independently of hsCRP, possibly via pleiotropic effects.

Glycosaminoglycans: Participants in Microvascular Coagulation of Sepsis

Sepsis represents a syndromic response to infection and frequently acts as a common pathway leading to fatality in the context of various infectious diseases globally. The pathology of severe sepsis is marked by an excess of inflammation and activated coagulation. A substantial contributor to mortality in sepsis patients is widespread microvascular thrombosis-induced organ dysfunction. Multiple lines of evidence support the notion that sepsis induces endothelial damage, leading to the release of glycosaminoglycans, potentially causing microvascular dysfunction. This review aims to initially elucidate the relationship among endothelial damage, excessive inflammation, and thrombosis in sepsis. Following this, we present a summary of the involvement of glycosaminoglycans in coagulation, elucidating interactions among glycosaminoglycans, platelets, and inflammatory cells. In this section, we also introduce a reasoned generalization of potential signal pathways wherein glycosaminoglycans play a role in clotting. Finally, we discuss current methods for detecting microvascular conditions in sepsis patients from the perspective of glycosaminoglycans. In conclusion, it is imperative to pay closer attention to the role of glycosaminoglycans in the mechanism of microvascular thrombosis in sepsis. Dynamically assessing glycosaminoglycan levels in patients may aid in predicting microvascular conditions, enabling the monitoring of disease progression, adjustment of clinical treatment schemes, and mitigation of both acute and long-term adverse outcomes associated with sepsis.

Advances in the Anti-Atherosclerotic Mechanisms of Epigallocatechin Gallate

Atherosclerosis (AS) is a common clinical sickness and the major pathological basis of ischemic cardiocerebrovascular diseases (CCVDs). The pathogenesis of AS involves a variety of risk factors, and there is a lack of effective preventive and curative drugs that can completely treat AS. In recent years, with the improvement of people's living standards and changes in dietary habits, the morbidity and mortality rates of AS are on the rise, and the age of onset tends to be younger. The formation of AS is closely related to a variety of factors, and the main factors include lipid metabolism disorders, endothelial damage, inflammation, unstable plaques, etc. Epigallocatechin gallate (EGCG), as one of the main components of catechins, has a variety of pharmacological effects, and its role in the prevention of AS and the protection of cardiovascular and cerebral blood vessels has been highly valued. Recent epidemiological investigations and various in vivo and ex vivo experiments have shown that EGCG is capable of resisting atherosclerosis and reducing the morbidity and mortality of AS. In this paper, we reviewed the anti-AS effects of EGCG and its mechanisms in recent years, including the regulation of lipid metabolism, regulation of intestinal flora disorders, improvement of vascular endothelial cell functions, inhibition of inflammatory factors expression, regulation of inflammatory signaling pathways, inhibition of matrix metalloproteinase (MMP) expression, and inhibition of platelet aggregation, which are helpful for the prevention of cardiocerebrovascular diseases.

Macrophage Ferroptosis Promotes MMP2/9 Overexpression Induced by Hemin in Hemorrhagic Plaque

BACKGROUND

 Intra-plaque hemorrhage (IPH) leads to rapid plaque progression and instability through upregulation of matrix metalloproteinases (MMPs) and collagen degradation. Hemoglobin-derived hemin during IPH promotes plaque instability. We investigated whether hemin affects MMP overexpression in macrophages and explored the underlying mechanisms.

MATERIAL AND METHODS

 In vivo, hemorrhagic plaque models were established in rabbits and ApoE-/- mice. Ferrostatin-1 was used to inhibit ferroptosis. Plaque size, collagen, and MMP2/9 levels were evaluated using immunohistochemistry, H&E, Sirius Red, and Masson staining. In vitro, mouse peritoneal macrophages were extracted. Western blot and ELISA were used to measure MMP2/9 levels. Bioinformatics analysis investigated the association between MMPs and ferroptosis pathway genes. Macrophage ferroptosis was assessed by evaluating cell viability, lipid reactive oxygen species, mitochondrial ultrastructure, iron content, and COX2 levels after pretreatment with cell death inhibitors. Hemin's impact on ferroptosis and MMP expression was studied using Ferrostatin-1 and SB202190.

RESULTS

 In the rabbit hemorrhagic plaques, hemin deposition and overexpression of MMP2/9 were observed, particularly in macrophage-enriched regions. In vitro, hemin induced ferroptosis and MMP2/9 expression in macrophages. Ferrostatin-1 and SB202190 inhibited hemin-induced MMP2/9 overexpression. Ferrostatin-1 inhibited p38 phosphorylation in macrophages. Ferostatin-1 inhibits macrophage ferroptosis, reduces MMP2/9 levels in plaques, and stabilizes the hemorrhagic plaques.

CONCLUSION

 Our results suggested that hemin-induced macrophage ferroptosis promotes p38 pathway activation and MMP2/9 overexpression, which may play a crucial role in increasing hemorrhagic plaque vulnerability. These findings provide insights into the pathogenesis of hemorrhagic plaques and suggest that targeting macrophage ferroptosis may be a promising strategy for stabilizing vulnerable plaque.

Comparative Analysis of the Anti-Inflammatory Effects of Liraglutide and Dulaglutide

Inflammation plays a pathophysiological role in atherosclerosis and its clinical consequences. In addition to glycemic control, glucagon-like peptide-1 receptor agonists (GLP-1RAs) are of wide concern for cardioprotective effects. The structure, half-life, homology, and clinical efficacy of GLP-1RAs exhibit remarkable disparity. Several studies have compared the disparities in anti-inflammatory effects between daily and weekly GLP-1RAs. This study aimed to compare the similarities and differences between liraglutide and dulaglutide in terms of inhibiting atherosclerotic inflammation and improving co-cultured endothelial cell function. The expression of inflammation markers was examined by immunofluorescence, Western blotting, and real-time PCR. The tube-forming ability of endothelial cells was tested on Matrigel. The results verify that 10/50/100 nmol/L liraglutide and 100 nmol/L dulaglutide markedly suppressed the expression of inflammatory factors in LPS-induced atherosclerosis after 24 and 72 hours, respectively. Moreover, they promoted the polarization of M1 macrophages toward the M2 phenotype and improved the function of co-cultured endothelial cells. Both liraglutide and dulaglutide ameliorate atherosclerosis development. The difference between the two resided in the extended intervention duration required to observe the effect of dulaglutide, and liraglutide demonstrated a superior dose-dependent manner. We provide a potential strategy to understand the dynamics of drug action and possible timing administration.

Pharmacological Inhibition of MMP-12 Exerts Protective Effects on Angiotensin II-Induced Abdominal Aortic Aneurysms in Apolipoprotein E-Deficient Mice

Human abdominal aortic aneurysms (AAAs) are characterized by increased activity of matrix metalloproteinases (MMP), including MMP-12, alongside macrophage accumulation and elastin degradation, in conjunction with superimposed atherosclerosis. Previous genetic ablation studies have proposed contradictory roles for MMP-12 in AAA development. In this study, we aimed to elucidate if pharmacological inhibition of MMP-12 activity with a phosphinic peptide inhibitor protects from AAA formation and progression in angiotensin (Ang) II-infused Apoe-/- mice. Complimentary studies were conducted in a human ex vivo model of early aneurysm development. Administration of an MMP-12 inhibitor (RXP470.1) protected hypercholesterolemia Apoe-/- mice from Ang II-induced AAA formation and rupture-related death, associated with diminished medial thinning and elastin fragmentation alongside increased collagen deposition. Proteomic analyses confirmed a beneficial effect of MMP-12 inhibition on extracellular matrix remodeling proteins combined with inflammatory pathways. Furthermore, RXP470.1 treatment of mice with pre-existing AAAs exerted beneficial effects as observed through suppressed aortic dilation and rupture, medial thinning, and elastin destruction. Our findings indicate that pharmacological inhibition of MMP-12 activity retards AAA progression and improves survival in mice providing proof-of-concept evidence to motivate translational work for MMP-12 inhibitor therapy in humans.

Effects of mitochondrial dysfunction on cellular function: Role in atherosclerosis

Atherosclerosis, an immunoinflammatory disease of medium and large arteries, is associated with life-threatening clinical events, such as acute coronary syndromes and stroke. Chronic inflammation and impaired lipoprotein metabolism are considered to be among the leading causes of atherosclerosis, while numerous risk factors, including arterial hypertension, diabetes mellitus, obesity, and aging, can contribute to the development of the disease. In recent years, emerging evidence has underlined the key role of mitochondrial dysfunction in the pathogenesis of atherosclerosis. Mitochondrial dysfunction is believed to result in an increase in reactive oxygen species, leading to oxidative stress, chronic inflammation, and intracellular lipid deposition, all of which can contribute to the pathogenesis of atherosclerosis. Critical cells, including endothelial cells, vascular smooth muscle cells, and macrophages, play an important role in atherosclerosis. Mitochondrial function is also involved in maintaining the normal function of these cells. To better understand the relationship between mitochondrial dysfunction and atherosclerosis, this review summarizes the findings of recent studies and discusses the role of mitochondrial dysfunction in the risk factors and critical cells of atherosclerosis. FACTS: OPEN QUESTIONS.

Matrix metalloproteinases in chronic rhinosinusitis

INTRODUCTION

Matrix metalloproteinases (MMPs) are a group of enzymes that are essential in maintaining extracellular matrix (ECM) homeostasis, regulating inflammation and tissue remodeling. In chronic rhinosinusitis (CRS), the overexpression of certain MMPs can contribute to chronic nasal tissue inflammation, ECM remodeling, and tissue repair.

AREAS COVERED

This review provides a comprehensive overview of the biological characteristics and functions of the MMP family, particularly focusing on the expression and activity of MMPs in patients with CRS, and delves into their role in the pathogenesis of CRS and their potential as therapeutic targets.

EXPERT OPINION

MMPs are important in tissue remodeling and have been implicated in the pathophysiology of CRS. Previous studies have shown that the expression of MMPs is upregulated in the nasal mucosa of patients with CRS and positively correlates with the severity of CRS. However, there is still a large gap in the research content of MMP in CRS, and the specific expression and pathogenic mechanism of MMP still need to be clarified. The significance and value of the ratio of MMP to tissue inhibitors of metalloproteinase (TIMP) in diseases still need to be demonstrated. Moreover, further studies are needed to assess the efficacy and safety of biologics that target MMPs in patients with CRS.

Design and Fabrication of Environmentally Responsive Nanoparticles for the Diagnosis and Treatment of Atherosclerosis

Cardiovascular disease poses a significant threat to human health in today's society. A major contributor to cardiovascular disease is atherosclerosis (AS). The development of plaque in the affected areas involves a complex pathological environment, and the disease progresses rapidly. Nanotechnology, combined with emerging diagnostic and treatment methods, offers the potential for the management of this condition. This paper presents the latest advancements in environment-intelligent responsive controlled-release nanoparticles designed specifically for the pathological environment of AS, which includes characteristics such as low pH, high reactive oxygen species levels, high shear stress, and multienzymes. Additionally, the paper summarizes the applications and features of nanotechnology in interventional therapy for AS, including percutaneous transluminal coronary angioplasty and drug-eluting stents. Furthermore, the application of nanotechnology in the diagnosis of AS shows promising real-time, accurate, and continuous effects. Lastly, the paper explores the future prospects of nanotechnology, highlighting the tremendous potential in the diagnosis and treatment of atherosclerotic diseases, especially with the ongoing development in nano gas, quantum dots, and Metal-Organic Frameworks materials.

Invasive coronary imaging of inflammation to further characterize high-risk lesions: what options do we have?

Coronary atherosclerosis remains a leading cause of morbidity and mortality worldwide. The underlying pathophysiology includes a complex interplay of endothelial dysfunction, lipid accumulation and inflammatory pathways. Multiple structural and inflammatory features of the atherosclerotic lesions have become targets to identify high-risk lesions. Various intracoronary imaging devices have been developed to assess the morphological, biocompositional and molecular profile of the intracoronary atheromata. These techniques guide interventional and therapeutical management and allow the identification and stratification of atherosclerotic lesions. We sought to provide an overview of the inflammatory pathobiology of atherosclerosis, distinct high-risk plaque features and the ability to visualize this process with contemporary intracoronary imaging techniques.

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.

Pathogenetic mechanisms of repeated adverse cardiovascular events development in patients with coronary heart disease: the role of chronic inflammation

Stent restenosis is the most unfavorable complication of interventional treatment for coronary heart disease. We already know from various literature sources that the causes for stent restenosis in patients are both mechanical damage (partial opening, stent breakage, extended stented area, calcification, incomplete stent coverage of atherosclerotic plaque, weak radial stiffness of the stent metal frame, lack of stent drug coating), and the neointimal hyperplasia formation which is closely related to the de novo atherosclerosis development, being a predictor of the recurrent cardiovascular event.

RNA interference-based therapies for atherosclerosis: Recent advances and future prospects

Atherosclerosis represents a pathological state that affects the arterial system of the organism. This chronic, progressive condition is typified by the accumulation of atheroma within arterial walls. Modulation of RNA molecules through RNA-based therapies has expanded the range of therapeutic options available for neurodegenerative diseases, infectious diseases, cancer, and, more recently, cardiovascular disease (CVD). Presently, microRNAs and small interfering RNAs (siRNAs) are the most widely employed therapeutic strategies for targeting RNA molecules, and for regulating gene expression and protein production. Nevertheless, for these agents to be developed into effective medications, various obstacles must be overcome, including inadequate binding affinity, instability, challenges of delivering to the tissues, immunogenicity, and off-target toxicity. In this comprehensive review, we discuss in detail the current state of RNA interference (RNAi)-based therapies.

The microenvironment of the atheroma expresses phenotypes of plaque instability

Data from histopathology studies of human atherosclerotic tissue specimens and from vascular imaging studies support the concept that the local arterial microenvironment of a stable atheroma promotes destabilizing conditions that result in the transition to an unstable atheroma. Destabilization is characterized by several different plaque phenotypes that cause major clinical events such as acute coronary syndrome and cerebrovascular strokes. There are several rupture-associated phenotypes causing thrombotic vascular occlusion including simple fibrous cap rupture of an atheroma, fibrous cap rupture at site of previous rupture-and-repair of an atheroma, and nodular calcification with rupture. Endothelial erosion without rupture has more recently been shown to be a common phenotype to promote thrombosis as well. Microenvironment features that are linked to these phenotypes of plaque instability are neovascularization arising from the vasa vasorum network leading to necrotic core expansion, intraplaque hemorrhage, and cap rupture; activation of adventitial and perivascular adipose tissue cells leading to secretion of cytokines, growth factors, adipokines in the outer artery wall that destabilize plaque structure; and vascular smooth muscle cell phenotypic switching through transdifferentiation and stem/progenitor cell activation resulting in the promotion of inflammation, calcification, and secretion of extracellular matrix, altering fibrous cap structure, and necrotic core growth. As the technology evolves, studies using noninvasive vascular imaging will be able to investigate the transition of stable to unstable atheromas in real time. A limitation in the field, however, is that reliable and predictable experimental models of spontaneous plaque rupture and/or erosion are not currently available to study the cell and molecular mechanisms that regulate the conversion of the stable atheroma to an unstable plaque.

Sustained low-grade inflammation in young participants with childhood onset type 1 diabetes: The Norwegian atherosclerosis and childhood diabetes (ACD) study

BACKGROUND AND AIMS

Persons with type 1 diabetes (T1D) have increased mortality from cardiovascular disease. Early inflammation is important in the development of atherosclerosis. We aimed to evaluate the extent of inflammation and difference in mean over a five-year period in young persons with T1D compared to healthy controls.

METHODS

The Norwegian Atherosclerosis and Childhood Diabetes (ACD) study is a prospective population-based cohort study on atherosclerosis development in childhood-onset T1D compared to healthy controls, with follow-ups every fifth year. The original study cohort consisted of 314 children with T1D on intensive insulin treatment and 120 healthy controls of similar age. Circulating levels of VCAM-1, TNA-α, P-selectin, E-selectin, CRP, IL-6, IL-18, MCP-1, MMP-9 and TIMP-1 were measured by ELISAs at baseline and at the five-year follow-up.

RESULTS

The group with T1D had mean age 13.7 (SD = 2.8) years, disease duration 5.6 (SD = 3.4) years and HbA1c 68 (SD = 13.1) mmol/mol at baseline. Levels of almost all inflammatory markers were significantly increased in the group with T1D compared to controls, and significant mean-difference between the two groups over the five-year period was observed in four markers: IL-18, P-selectin, E-selectin and TIMP-1.

CONCLUSIONS

The early low-grade inflammation present in young individuals with T1D five years after diagnosis is sustained at ten-year disease duration, with moderate changes for most markers of inflammation over time. The evolving inflammatory profile indicates an accelerated chain of events in the progression of early atheromatosis in T1D.

Proteomics Studies Suggest That Nitric Oxide Donor Furoxans Inhibit In Vitro Vascular Smooth Muscle Cell Proliferation by Nitric Oxide-Independent Mechanisms

Physiologically, smooth muscle cells (SMC) and nitric oxide (NO) produced by endothelial cells strictly cooperate to maintain vasal homeostasis. In atherosclerosis, where this equilibrium is altered, molecules providing exogenous NO and able to inhibit SMC proliferation may represent valuable antiatherosclerotic agents. Searching for dual antiproliferative and NO-donor molecules, we found that furoxans significantly decreased SMC proliferation in vitro, albeit with different potencies. We therefore assessed whether this property is dependent on their thiol-induced ring opening. Indeed, while furazans (analogues unable to release NO) are not effective, furoxans' inhibitory potency parallels with the electron-attractor capacity of the group in 3 of the ring, making this effect tunable. To demonstrate whether their specific block on G1-S phase could be NO-dependent, we supplemented SMCs with furoxans and inhibitors of GMP- and/or of the polyamine pathway, which regulate NO-induced SMC proliferation, but they failed in preventing the antiproliferative effect. To find the real mechanism of this property, our proteomics studies revealed that eleven cellular proteins (with SUMO1 being central) and networks involved in cell homeostasis/proliferation are modulated by furoxans, probably by interaction with adducts generated after degradation. Altogether, thanks to their dual effect and pharmacological flexibility, furoxans may be evaluated in the future as antiatherosclerotic molecules.

Investigating the association between serum ADAM/ADAMTS levels and bone mineral density by mendelian randomization study

PURPOSE

A Disintegrin and Metalloproteinase (ADAM) and A Disintegrin and Metalloproteinase with Thrombospondin Motif (ADAMTS) have been reported potentially involved in bone metabolism and related to bone mineral density. This Mendelian Randomization (MR) analysis was performed to determine whether there are causal associations of serum ADAM/ADAMTS with BMD in rid of confounders.

METHODS

The genome-wide summary statistics of four site-specific BMD measurements were obtained from studies in individuals of European ancestry, including forearm (n = 8,143), femoral neck (n = 32,735), lumbar spine (n = 28,498) and heel (n = 426,824). The genetic instrumental variables for circulating levels of ADAM12, ADAM19, ADAM23, ADAMTS5 and ADAMTS6 were retrieved from the latest genome-wide association study of European ancestry (n = 5336 ~ 5367). The estimated causal effect was given by the Wald ratio for each variant, the inverse-variance weighted model was used as the primary approach to combine estimates from multiple instruments, and sensitivity analyses were conducted to assess the robustness of MR results. The Bonferroni-corrected significance was set at P < 0.0025 to account for multiple testing, and a lenient threshold P < 0.05 was considered to suggest a causal relationship.

RESULTS

The causal effects of genetically predicted serum ADAM/ADAMTS levels on BMD measurements at forearm, femoral neck and lumbar spine were not statistically supported by MR analyses. Although causal effect of ADAMTS5 on heel BMD given by the primary MR analysis (β = -0.006, -0.010 to 0.002, P = 0.004) failed to reach Bonferroni-corrected significance, additional MR approaches and sensitivity analyses indicated a robust causal relationship.

CONCLUSION

Our study provided suggestive evidence for the causal effect of higher serum levels of ADAMTS5 on decreased heel BMD, while there was no supportive evidence for the associations of ADAM12, ADAM19, ADAM23, and ADAMTS6 with BMD at forearm, femoral neck and lumbar spine in Europeans.

Targeting mitochondrial function in macrophages: A novel treatment strategy for atherosclerotic cardiovascular disease?

Atherosclerotic cardiovascular disease is a major cause of morbidity and mortality due to chronic arterial injury caused by hyperlipidemia, hypertension, inflammation and oxidative stress. Recent studies have shown that the progression of this disease is associated with mitochondrial dysfunction and with the accumulation of mitochondrial alterations within macrophages of atherosclerotic plaques. These alterations contribute to processes of inflammation and oxidative stress. Among the many players involved, macrophages play a pivotal role in atherogenesis as they can exert both beneficial and deleterious effects due to their anti- and pro-inflammatory properties. Their atheroprotective functions, such as cholesterol efflux and efferocytosis, as well as the maintenance of their polarization towards an anti-inflammatory state, are particularly dependent on mitochondrial metabolism. Moreover, in vitro studies have demonstrated deleterious effects of oxidized LDL on macrophage mitochondrial function, resulting in a switch to a pro-inflammatory state and to a potential loss of atheroprotective capacity. Therefore, preservation of mitochondrial function is now considered a legitimate therapeutic strategy. This review focuses on the potential therapeutic strategies that could improve the mitochondrial function of macrophages, enabling them to maintain their atheroprotective capacity. These emerging therapies could play a valuable role in counteracting the progression of atherosclerotic lesions and possibly inducing their regression.

Serum levels of Matrix Metalloproteinases (MMPs) in patients undergoing endovascular intervention for peripheral arterial disease

OBJECTIVES

Matrix metalloproteinases (MMPs) play a significant role in the development and progression of atherosclerotic vascular disease. The purpose of this study was to measure and document the profile of plasma circulating MMPs in patients with peripheral arterial disease (PAD) undergoing endovascular revascularization.

METHODS

This was a single centre prospective observational study with 80 patients with PAD enrolled. They underwent percutaneous balloon angioplasty and/or angioplasty with stent. Exclusion criteria were acute limb ischemia, active inflammation, wet gangrene, liver disease, end stage renal failure and cancer. Patients that underwent open or hybrid (open and endovascular) approach, were also excluded from the study. Venous blood samples were taken preoperatively, 24 hours and 6 months postoperatively. The values of MMP-2, MMP-3, MMP-7, MMP-9 and their inhibitors (Tissue Inhibitor of metalloproteinases, TIMP), TIMP-1 and TIMP-2 were measured.

RESULTS

The mean age was 67.1 years and 66 of them (82.5%) were male. During the clinical follow up (mean 35.8% months), 12 patients died (16.4%), 15 (20.5%) of them had a major adverse limb event (MALE) and 14 (19.2%) of them had a major adverse cardiovascular event (MACE). There was a statistically significant raise in the values of MMP-2. MMP-3 and MMP-7 at 6 months postoperatively, when compared to the preoperative and 24 hours postoperative values. There was no correlation of MMP and TIMP values with mortality, MALE and MACE events.

CONCLUSIONS

The present single-centre prospective study documented increased circulating levels of MMPs post-operatively in PAD patients undergoing endovascular treatment. Vascular trauma caused by angioplasty, could trigger expression of MMPs and TIMPs, but the absence of any association with clinical complications requires further investigation.

MMPs, ADAMs and ADAMTSs are associated with mammalian sperm fate

Metalloproteinases include matrix metalloproteinases and disintegrin metalloproteinases. They are important members of the ECM degradation and reconstruction process and are associated with tissue development and disease. The ECM is a three-dimensional network of large molecules consisting of a variety of proteins. It is a physical scaffold for organs, and all types of cells can be found within the ECM. The testicle, where sperm are produced, is an organ that is constantly in dynamic flux. Metalloproteinases can regulate testicular tissue development and the maturation of sperm by affecting the ECM. Metalloproteinase disorders can lead to cryptorchidism, azoospermia, poor semen quality and other diseases. As a member of the metalloproteinase family, ADAMTS plays an important role in testicular slippage to the scrotum. ADAM is involved in the fertilization process, and excessive MMP can damage the BTB. In the testis, metalloproteinase stability represents the stability of the extracellular microenvironment in which germ cells are located and is associated with reproductive function. Metalloproteinases have a definite relationship with male reproduction, but the underlying mechanism is still unclear. This paper summarizes the literature on various metalloproteinases in testicular tissue physiology and pathology to elucidate their role in reproductive function and male reproductive mechanisms.

Berberine regulates bone metabolism in apical periodontitis by remodelling the extracellular matrix

OBJECTIVES

The objectives of this study were to explore the role and related mechanism of berberine in repairing bone destruction in apical periodontics (AP).

MATERIALS AND METHODS

AP was established in 14 of 21 male Wistar rats (four weeks of age; 70-80 g) for 3 weeks. The canals were cleaned and administered berberine (2 mg/ml; n = 7) or calcium hydroxide (100 mg/ml; control; n = 7), followed by glass ionomer cement sealing. After 3 weeks, specimen collection followed by micro-computed tomography (μ-CT) and histological staining was performed, including haematoxylin and eosin staining, Masson's trichrome staining, tartrate-resistant acid phosphatase staining, immunohistochemistry and immunofluorescence histochemistry.

RESULTS

μ-CT showed that AP lesion volume reduced in the berberine group. Histopathology showed that berberine decreased the activity and number of osteoclasts but increased the expression of proteins related to osteoblast differentiation, including alkaline phosphatase and osterix. The immune cell, T cell, dendritic cell and macrophage counts were significantly decreased in the berberine group. In the berberine group, the expression of extracellular matrix-degraded proteases, metalloproteinases, was decreased; however, that of extracellular matrix-stable proteases, lysyl oxidases, was increased.

CONCLUSIONS

Berberine controlled the inflammatory response and regulated bone metabolism in AP by reducing metalloproteinase expression and increasing lysyl oxidases expression.

Cadmium exposure induces histological damage and cytotoxicity in the cardiovascular system of mice

Epidemiological studies have reported an association between chronic cadmium (Cd) exposure and increased cardiovascular risk; however, their causal relationship remains unclear. The aim of this study is to explore the effects of Cd exposure on the cardiac and arterial systems in mice. According to the concentration of cadmium chloride in drinking water, male mice were randomly divided into control and low-dose and high-dose Cd exposure groups. The intervention duration was 12 weeks. In cardiac tissues, Cd exposure led to focal necrosis, myofibril disarray, perivascular and interstitial fibrosis, and disorganized sarcomere structures. Cd also induced the apoptosis of cardiomyocytes and increased the expression levels of matrix metalloproteinase (MMP)-2 and MMP-14 in cardiac tissues. In the arterial tissues, Cd exposure damaged the intimal and medial layers of the aorta. Cd further reduced the viability of aortic smooth muscle cells in vitro. This study provides evidence for the Cd-induced damage of the cardiovascular system, which may contribute to various cardiovascular diseases.

Properties and fate of human mesenchymal stem cells upon miRNA let-7f-promoted recruitment to atherosclerotic plaques

AIMS

Atherosclerosis is a chronic inflammatory disease of the arteries leading to the formation of atheromatous plaques. Human mesenchymal stem cells (hMSCs) are recruited from the circulation into plaques where in response to their environment they adopt a phenotype with immunomodulatory properties. However, the mechanisms underlying hMSC function in these processes are unclear. Recently, we described that miRNA let-7f controls hMSC invasion guided by inflammatory cytokines and chemokines. Here, we investigated the role of let-7f in hMSC tropism to human atheromas and the effects of the plaque microenvironment on cell fate and release of soluble factors.

METHODS AND RESULTS

Incubation of hMSCs with LL-37, an antimicrobial peptide abundantly found in plaques, increased biosynthesis of let-7f and N-formyl peptide receptor 2 (FPR2), enabling chemotactic invasion of the cells towards LL-37, as determined by qRT-PCR, flow cytometry, and cell invasion assay analysis. In an Apoe-/- mouse model of atherosclerosis, circulating hMSCs preferentially adhered to athero-prone endothelium. This property was facilitated by elevated levels of let-7f in the hMSCs, as assayed by ex vivo artery perfusion and two-photon laser scanning microscopy. Exposure of hMSCs to homogenized human atheromatous plaque material considerably induced the production of various cytokines, chemokines, matrix metalloproteinases, and tissue inhibitors of metalloproteinases, as studied by PCR array and western blot analysis. Moreover, exposure to human plaque extracts elicited differentiation of hMSCs into cells of the myogenic lineage, suggesting a potentially plaque-stabilizing effect.

CONCLUSIONS

Our findings indicate that let-7f promotes hMSC tropism towards atheromas through the LL-37/FPR2 axis and demonstrate that hMSCs upon contact with human plaque environment develop a potentially athero-protective signature impacting the pathophysiology of atherosclerosis.

Association of LDLR, TP53 and MMP9 Gene Polymorphisms With Atherosclerosis in a Malaysian Study Population

Preliminary research has shown that low density lipoprotein receptor (LDLR), tumor protein (TP53) and matrix metalloproteinase 9 (MMP9) genes expression levels were significantly increased in atherosclerosis coronary artery tissue (ACAT) compared to non-atherosclerotic coronary artery tissue (NCAT) samples. Thus, further investigation was carried out to study the association of LDLR, TP53 and MMP9 gene polymorphisms and the risk of developing atherosclerosis (ATH) in a Malaysian population. Single nucleotide polymorphisms of C88S, TP53 codon 72 and MMP9C>T were analyzed in 76 ACAT samples and 149 NCAT samples, representing cases and controls, respectively. In results, heterozygous CT genotype of MMP9C>T polymorphism was significantly higher in ACAT compared to NCAT samples (57.9% vs 27.5%, χ² = 19.758, df= 1, P < 0.05). The CT genotype was found to be significantly associated with the risk of developing ATH (OR = 3.622, 95% CI = 2.028-6.470). However, the distribution of the CT genotype in a healthy Malaysian study population was incomparable regardless of gender and ethnicity. The DNA sequencing results validated the C88S, TP53 codon 72, and MMP9C>T polymorphisms. In conclusion, the CT genotype of the MMP9-1562C>T polymorphism was found to have a strong association with the risk of developing ATH.

LIM Homeobox 2 Increases Adhesion-Regulating Molecule 1 Transcription to Facilitate the Pathological Progression of Oxidized Low-Density Lipoprotein-Stimulated Atherosclerotic Cell Models

Endothelial-mesenchymal transition (EndMT) and endothelial cell apoptosis have been documented to have a role in atherosclerosis (AS) progression. To deepen knowledge in this aspect, our study investigated the effect of LIM homeobox 2 (LHX2) and adhesion-regulating molecule 1 (ADRM1) on EndMT and endothelial cell apoptosis in the oxidized low-density lipoprotein (ox-LDL) -stimulated AS cell model.Ox-LDL was utilized to treat human umbilical vein endothelial cells (HUVECs) for constructing an AS model in vitro, followed by measurement of LHX2 and ADRM1 expressions. Afterward, gain- and loss-of-function assays were performed in HUVECs, followed by detection of cell viability, invasion, migration, and apoptosis and the expression of inflammatory factors [tumor necrosis factor (TNF) -α, interleukin (IL) -1β, and IL-6], EndMT-related proteins [CD31, vascular epithelium (VE) -cadherin, vimentin, α-smooth muscle actin (SMA), Snai1, Snai2, and Twist1], and the apoptotic protein cleaved caspase-3. Interactions between LHX2 and ADRM1 were analyzed with dual-luciferase reporter gene and chromatin immunoprecipitation assays.High levels of LHX2 and ADRM1 were observed in ox-LDL-induced HUVECs. In ox-LDL-treated HUVECs, LHX2, or ADRM1 knockdown promoted CD31 and VE-cadherin levels, viability, invasion, and migration and reduced apoptosis and the expressions of TNF-α, IL-1β, IL-6, vimentin, α-SMA, Snai1, Snai2, Twist1, and cleaved caspase-3. Mechanistically, LHX2 bound to the ADRM1 promoter to promote ADRM1 transcription. Overexpression of ADRM1 annulled the aforementioned effects of LHX2 knockdown on ox-LDL-induced HUVECs.LHX2 facilitates the pathological progression of ox-LDL-stimulated AS cell models by increasing ADRM1 transcription.

Ox-LDL-Induced Vascular Smooth Muscle Cell Dysfunction Partly Depends on the Circ_0044073/miR-377-3p/AURKA Axis in Atherosclerosis

Atherosclerosis (AS) is the main reason for most cardiovascular diseases. Circular RNA hsa_circ_0044073 (circ_0044073) has been found to promote AS progression. However, the specific regulatory mechanism of circ_0044073 in AS progression remains unclear.In this study, oxidized low-density lipoprotein (Ox-LDL) -stimulated human vascular smooth muscle cells (VSMCs) were used as AS cell models. The expression changes of circ_0044073 in serum samples and Ox-LDL-stimulated human VSMCs were assessed via real-time quantitative polymerase chain reaction (RT-qPCR). Cell viability, proliferation, colony formation, migration, and invasion were assessed using 3- (4,5-Dimethylthiazol-2-yl) -2,5-Diphenyltetrazolium Bromide (MTT), 5-ethynyl-2'-deoxyuridine (EDU), colony formation, and transwell assays. Some protein levels were detected via Western blotting. The regulatory mechanism of circ_0044073 was predicted using bioinformatics analysis and validated by dual-luciferase reporter and RNA pull-down assays.We observed an overt increase in circ_0044073 expression in serum samples derived from AS patients and Ox-LDL-stimulated human VSMCs. Circ_0044073 was identified as a miR-377-3p sponge. Either circ_0044073 knockdown or miR-377-3p overexpression could impair Ox-LDL-induced human VSMC proliferation, migration, invasion, and inflammation. AURKA served as a miR-377-3p target, and circ_0044073 regulated AURKA expression by adsorbing miR-377-3p. Furthermore, AURKA overexpression partly reversed the effects of circ_0044073 inhibition on Ox-LDL-induced human VSMC proliferation, migration, invasion, and inflammation.Circ_0044073 promoted AS progression by elevating AURKA expression by functioning as a miR-377-3p sponge. Providing a proof-of-concept demonstration to support circ_0044073 might be a target for AS treatment.

Circulating Biomarkers for Laboratory Diagnostics of Atherosclerosis-Literature Review

Atherosclerosis is still considered a disease burden with long-term damaging processes towards the cardiovascular system. Evaluation of atherosclerotic stages requires the use of independent markers such as those already considered traditional, that remain the main therapeutic target for patients with atherosclerosis, together with emerging biomarkers. The challenge is finding models of predictive markers that are particularly tailored to detect and evaluate the evolution of incipient vascular lesions. Important advances have been made in this field, resulting in a more comprehensible and stronger linkage between the lipidic profile and the continuous inflammatory process. In this paper, we analysed the most recent data from the literature studying the molecular mechanisms of biomarkers and their involvement in the cascade of events that occur in the pathophysiology of atherosclerosis.

Role of metalloproteases in the CD95 signaling pathways

CD95L (also known as FasL or CD178) is a member of the tumor necrosis family (TNF) superfamily. Although this transmembrane ligand has been mainly considered as a potent apoptotic inducer in CD95 (Fas)-expressing cells, more recent studies pointed out its role in the implementation of non-apoptotic signals. Accordingly, this ligand has been associated with the aggravation of inflammation in different auto-immune disorders and in the metastatic occurrence in different cancers. Although it remains to decipher all key factors involved in the ambivalent role of this ligand, accumulating clues suggest that while the membrane bound CD95L triggers apoptosis, its soluble counterpart generated by metalloprotease-driven cleavage is responsible for its non-apoptotic functions. Nonetheless, the metalloproteases (MMPs and ADAMs) involved in the CD95L shedding, the cleavage sites and the different stoichiometries and functions of the soluble CD95L remain to be elucidated. To better understand how soluble CD95L triggers signaling pathways from apoptosis to inflammation or cell migration, we propose herein to summarize the different metalloproteases that have been described to be able to shed CD95L, their cleavage sites and the biological functions associated with the released ligands. Based on these new findings, the development of CD95/CD95L-targeting therapeutics is also discussed.

Vitamin D deficiency in British South Asians, a persistent but avoidable problem associated with many health risks (including rickets, T2DM, CVD, COVID-19 and pregnancy complications): the case for correcting this deficiency

High vitamin D deficiency rates, with rickets and osteomalacia, have been common in South Asians (SAs) arriving in Britain since the 1950s with preventable infant deaths from hypocalcaemic status-epilepticus and cardiomyopathy. Vitamin D deficiency increases common SA disorders (type 2 diabetes and cardiovascular disease), recent trials and non-linear Mendelian randomisation studies having shown deficiency to be causal for both disorders. Ethnic minority, obesity, diabetes and social deprivation are recognised COVID-19 risk factors, but vitamin D deficiency is not, despite convincing mechanistic evidence of it. Adjusting analyses for obesity/ethnicity abolishes vitamin D deficiency in COVID-19 risk prediction, but both factors lower serum 25(OH)D specifically. Social deprivation inadequately explains increased ethnic minority COVID-19 risks. SA vitamin D deficiency remains uncorrected after 70 years, official bodies using 'education', 'assimilation' and 'diet' as 'proxies' for ethnic differences and increasing pressures to assimilate. Meanwhile, English rickets was abolished from ~1940 by free 'welfare foods' (meat, milk, eggs, cod liver oil), for all pregnant/nursing mothers and young children (<5 years old). Cod liver oil was withdrawn from antenatal clinics in 1994 (for excessive vitamin A teratogenicity), without alternative provision. The take-up of the 2006 'Healthy-Start' scheme of food-vouchers for low-income families with young children (<3 years old) has been poor, being inaccessible and poorly publicised. COVID-19 pandemic advice for UK adults in 'lockdown' was '400 IU vitamin D/day', inadequate for correcting the deficiency seen winter/summer at 17.5%/5.9% in White, 38.5%/30% in Black and 57.2%/50.8% in SA people in representative UK Biobank subjects when recruited ~14 years ago and remaining similar in 2018. Vitamin D inadequacy worsens many non-skeletal health risks. Not providing vitamin D for preventing SA rickets and osteomalacia continues to be unacceptable, as deficiency-related health risks increase ethnic health disparities, while abolishing vitamin D deficiency would be easier and more cost-effective than correcting any other factor worsening ethnic minority health in Britain.

Epigenetic regulation in myocardial infarction: Non-coding RNAs and exosomal non-coding RNAs

Myocardial infarction (MI) is one of the leading causes of deaths globally. The early diagnosis of MI lowers the rate of subsequent complications and maximizes the benefits of cardiovascular interventions. Many efforts have been made to explore new therapeutic targets for MI, and the therapeutic potential of non-coding RNAs (ncRNAs) is one good example. NcRNAs are a group of RNAs with many different subgroups, but they are not translated into proteins. MicroRNAs (miRNAs) are the most studied type of ncRNAs, and have been found to regulate several pathological processes in MI, including cardiomyocyte inflammation, apoptosis, angiogenesis, and fibrosis. These processes can also be modulated by circular RNAs and long ncRNAs via different mechanisms. However, the regulatory role of ncRNAs and their underlying mechanisms in MI are underexplored. Exosomes play a crucial role in communication between cells, and can affect both homeostasis and disease conditions. Exosomal ncRNAs have been shown to affect many biological functions. Tissue-specific changes in exosomal ncRNAs contribute to aging, tissue dysfunction, and human diseases. Here we provide a comprehensive review of recent findings on epigenetic changes in cardiovascular diseases as well as the role of ncRNAs and exosomal ncRNAs in MI, focusing on their function, diagnostic and prognostic significance.

miR-146-5p restrains calcification of vascular smooth muscle cells by suppressing TRAF6

Vascular calcification is a prominent manifestation of advanced atherosclerosis. Tumor necrosis factor-receptor-associated factors (TRAFs) were reported to participate in atherosclerosis development. In this study, the role and mechanism of TRAF6 in vascular calcification were explored. To induce the vascular calcification, oxidized low-density lipoprotein (Ox-LDL) was applied to treat vascular smooth muscle cells (VSMCs). TRAF6 protein expression in VSMCs was assessed by western blotting. Osteogenic differentiation of VSMCs was assessed by alkaline phosphatase activity analysis. Mineral deposition in VSMCs was evaluated by von Kossa staining. VSMC proliferation, migration, apoptosis, inflammation, and reactive oxygen species (ROS) generation were detected using cell counting kit-8, Transwell, flow cytometry, reverse transcriptase quantitative polymerase chain reaction (RT-qPCR), and dichlorodihydrofluorescein diacetate staining, respectively. Luciferase reporter assay was utilized to identify the binding relationship between miR-146-5p and TRAF6 in VSMCs. We found that Ox-LDL administration induced the calcification of VSMCs and elevated the TRAF6 level. TRAF6 knockdown restrained VSMC calcification, proliferation, migration, inflammation, and ROS generation caused by Ox-LDL. Mechanically, TRAF6 was targeted by miR-146-5p in VSMCs. Furthermore, TRAF6 overexpression offset the inhibitory effects of miR-146-5p upregulation on vascular calcification in VSMCs under the Ox-LDL condition. Overall, miR-146-5p restrains the calcification of VSMCs by suppressing TRAF6.

TIMP-1 expression in coronary thrombi associate with myocardial injury in ST-elevation myocardial infarction patients

BACKGROUND

Matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) are considered important both in atherosclerosis and remodeling after acute myocardial infarction (AMI). We aimed to study genetic expression and presence of MMP-2, MMP-9, TIMP-1, TIMP-2 and the extracellular MMP-inducer (EMMPRIN) in coronary thrombi. Circulating levels and genetic expression in circulating leukocytes were also assessed, and relations to degree of myocardial injury measured by troponin T and time from symptom to PCI were explored. Expression of cell markers were also analyzed, indicating relations to cell types.

METHODS

Intracoronary thrombi were aspirated from 33 patients with ST-elevation myocardial infarction (STEMI). Blood samples with Pax-gene tubes were drawn at end of PCI and the next day. RNA was isolated from thrombi and leukocytes, and genes were relatively quantified by RT-PCR. Each thrombus was preserved for histology and immunohistochemistry analyzes.

RESULTS

Genes coding for the five markers were present in 84-100% of thrombi and immunohistochemically stained in 96-100%. Expression of TIMP-1 in thrombi and in leukocytes correlated significantly to peak troponin T ( r = 0.393 P = 0.026, r = 0.469 P = 0.006, respectively). No significant correlations between genes expressed in thrombi and time from symptom to PCI were observed. TIMP-1 was connected mainly to monocytes/macrophages in the thrombi.

CONCLUSION

MMP-2, MMP-9, TIMP-1, TIMP-2 and EMMPRIN were highly expressed in human coronary thrombi. The correlation between troponin T and the expression of TIMP-1 both in thrombi and in leukocytes at time of PCI indicates that TIMP-1 plays a role in myocardial damage early post-MI.

Endothelial Glycocalyx

The glycocalyx is a polysaccharide structure that protrudes from the body of a cell. It is primarily conformed of glycoproteins and proteoglycans, which provide communication, electrostatic charge, ionic buffering, permeability, and mechanosensation-mechanotransduction capabilities to cells. In blood vessels, the endothelial glycocalyx that projects into the vascular lumen separates the vascular wall from the circulating blood. Such a physical location allows a number of its components, including sialic acid, glypican-1, heparan sulfate, and hyaluronan, to participate in the mechanosensation-mechanotransduction of blood flow-dependent shear stress, which results in the synthesis of nitric oxide and flow-mediated vasodilation. The endothelial glycocalyx also participates in the regulation of vascular permeability and the modulation of inflammatory responses, including the processes of leukocyte rolling and extravasation. Its structural architecture and negative charge work to prevent macromolecules greater than approximately 70 kDa and cationic molecules from binding and flowing out of the vasculature. This also prevents the extravasation of pathogens such as bacteria and virus, as well as that of tumor cells. Due to its constant exposure to shear and circulating enzymes such as neuraminidase, heparanase, hyaluronidase, and matrix metalloproteinases, the endothelial glycocalyx is in a continuous process of degradation and renovation. A balance favoring degradation is associated with a variety of pathologies including atherosclerosis, hypertension, vascular aging, metastatic cancer, and diabetic vasculopathies. Consequently, ongoing research efforts are focused on deciphering the mechanisms that promote glycocalyx degradation or limit its syntheses, as well as on therapeutic approaches to improve glycocalyx integrity with the goal of reducing vascular disease. © 2022 American Physiological Society. Compr Physiol 12: 1-31, 2022.

OLDER PATIENTS AND PATIENTS WITH SEVERE ARTERIOSCLEROSIS ARE LESS LIKELY TO DEVELOP KELOIDS AND HYPERTROPHIC SCARS AFTER THORACIC MIDLINE INCISION: A SURVEY-BASED ANALYSIS OF 328 CASES

BACKGROUND

Surgery is a well-known trigger of keloid and hypertrophic scarring. Sternotomy scars are subject to high skin tension, which is also known to promote pathological scarring. This suggests that sternotomies in adults associate with high pathological-scarring rates, which is also our anecdotal experience. However, this notion has never been formally examined. Therefore, we conducted a survey-based cohort study of patients who had undergone a sternotomy.

STUDY DESIGN

All consecutive Japanese adults (≥18 years) who underwent cardiovascular surgery with sternotomy in 2014-2017 were identified in 2019 by chart review and sent a questionnaire. Respondents formed the study cohort. The questionnaire presented randomly-ordered photos of representative mature, keloid, and hypertrophic scars and asked the patients to choose the image that best resembled their midline scar when it was particularly noticeable. The incidence of self-reported pathological scarring (keloids and hypertrophic scars were grouped together) and the patient demographic (age and sex) and clinical characteristics (e.g. intima media thickness of the left and right common and internal carotid arteries) that associated with pathological scarring were determined.

RESULTS

Of the 548 sternotomy patients, 328 (mean age, 67 years; 68.0% male) responded (60% response rate). Of these, 195 (59.5%) reported they had a pathological scar. Compared to mature-scar patients, pathological-scar patients had lower mean age (65 vs. 69 years, p=0.0002) and intima-media thickness (0.92 vs. 1.05 mm, p=0.028).

CONCLUSION

Sternotomy was associated with a high rate of pathological scarring. An older age and arteriosclerosis were associated with less pathological scarring.

Matrix metaloproteinases in vascular pathology

Vascular diseases are the main cause of morbidity and mortality. The vascular extracellular matrix (ECM) is essential in mechanical support, also regulating the cellular behavior fundamental to vascular function and homeostasis. Vascular remodeling is an adaptive response to various physiological and pathological changes and is associated with aging and vascular diseases. The aim of this review is provide a general overview of the involvement of MMPs in the pathogenesis of vascular diseases, namely, arterial hypertension, atherosclerosis, aortic aneurysms and myocardial infarction. The change in the composition of the ECM by matrix metalloproteinases (MMPs) generates a pro-inflammatory microenvironment that modifies the phenotypes of endothelial cells and vascular smooth muscle cells. They play a central role in morphogenesis, tissue repair and remodeling in response to injury, e.g., after myocardial infarction, and in progression of diseases such as atherosclerosis. Alterations in specific MMPs could influence arterial remodeling and lead to various pathological disorders such as hypertension and aneurysm formation. MMPs are regulated by endogenous tissue inhibitors of metalloproteinases (TIMPs), and the MMP/TIMP ratio generally determines the extent of ECM protein degradation and tissue remodeling. Studies are currently focused on improving the diagnostic and prognostic value of MMPs involved in the pathogenic process, increasing their therapeutic potential, and monitoring the disease. New selective MMP inhibitors may improve the specificity of these inhibitors, target specific MMPs in relevant pathological conditions and mitigate some of the side effects.

Effects of uric acid-lowering therapy in patients with essential arterial hypertension

OBJECTIVES

Asymptomatic hyperuricemia (AHU) is elevated serum uric acid (UA) without symptoms. This study aimed to determine the effects of AHU treatment with allopurinol on selected hypertension-mediated organ damage (HMOD) indices in patients with uncomplicated essential arterial hypertension (AH).

METHODS

Patients aged 30-70 years with AHU and AH grade 1-2 with adequate blood pressure (BP) control, without previous urate-lowering therapy (ULT), were divided into two groups: (a) ULT (receiving allopurinol) and (b) control (age- and sex-matched patients without ULT). Both received a UA-lowering diet. BP (office, 24 h and central), echocardiographic parameters, carotid intima-media thickness (IMT) and lab tests [high-sensitivity C-reactive protein (hs-CRP)] were measured at baseline and at 6 months follow-up.

RESULTS

Of 100 participants, 87 (44 ULT, 43 controls) completed the study. At 6 months follow-up, there was a greater reduction in serum UA concentration in the ULT group than in the control group. Patients receiving allopurinol had significant reductions in office systolic and diastolic BP, central systolic BP, pulse pressure, IMT (0.773 ± 0.121 vs. 0.752 ± 0.13 mm, P = 0.044) and hs-CRP (3.36 ± 2.73 vs. 2.74 ± 1.91 mg/L, P = 0.028) compared to controls. Multivariate regression analysis revealed the independent relationship between reduction in IMT and UA lowering (P < 0.026).

CONCLUSION

In patients with AH and AHU, treatment with allopurinol leads to improvement in BP control and reduction in HMOD intensity, in particular IMT. The decrease in hs-CRP concentration associated with ULT may have a beneficial effect on a patient's long-term prognosis.

Effect of Extracellular Vesicles From Multiple Cells on Vascular Smooth Muscle Cells in Atherosclerosis

Atherosclerosis (AS)-related diseases are still the main cause of death in clinical patients. The phenotype switching, proliferation, migration, and secretion of vascular smooth muscle cells (VSMCs) have a pivotal role in atherosclerosis. Although numerous research studies have elucidated the role of VSMCs in AS, their potential functional regulations continue to be explored. The formation of AS involves various cells, such as endothelial cells, smooth muscle cells, and macrophages. Therefore, intercellular communication of blood vessels cannot be ignored due to closely connected endothelia, media, and adventitia. Extracellular vesicles (EVs), as the vectors of cell-to-cell communication, can deliver proteins and nucleic acids of parent cells to the recipient cells. EVs have emerged as being central in intercellular communication and play a vital role in the pathophysiologic mechanisms of AS. This review summarizes the effects of extracellular vesicles (EVs) derived from multiple cells (endothelial cells, macrophages, mesenchymal stem cells, etc.) on VSMCs in AS. The key findings of this review are as follows: 1) endothelial cell–derived EVs (EEVs) have anti- or pro-atherogenic effects on VSMCs; 2) macrophage-derived EVs (MEVs) aggravate the proliferation and migration of VSMCs; 3) mesenchymal stem cells can inhibit VSMCs; and 4) the proliferation and migration of VSMCs can be inhibited by the treatment of EVs with atherosclerosis-protective factors and promoted by noxious stimulants. These results suggested that EVs have the same functional properties as treated parent cells, which might provide vital guidance for treating AS.

ONOO- -mediated oxidative modification of extracellular matrix aggravates atherosclerosis by affecting biological behaviors of vascular smooth muscle cells

Atherosclerosis (AS) is a principal contributor to stroke and coronary heart disease in humans characterized by chronic low-grade inflammation. The extracellular matrix (ECM) plays critical roles in regulating the function of arteries. However, the effect of changes in ECM on AS development is rarely studied. In this context, we intend to study the effect of oxidizing agent peroxynitrite (ONOO^- )-mediated oxidization of ECM proteins on the biological behaviors of vascular smooth muscle cells (SMCs) and the development of AS. AS mouse models were established, and mouse coronary artery smooth muscle cells (MCASMCs) were cultured in vitro to derive ECM (SMC-ECM), which was obtained by deoxycholate (DOC)-based decellularization. Further, MCASMCs were subjected to the determination of ECM oxidative damage and ECM protein structure. Finally, roles of ONOO^- -mediated oxidization of ECM in SMC adhesion and migration and in AS development were explored through Transwell assay, transcriptome sequencing, and gene enrichment analysis. High concentration of ONOO^- was found in the serum of AS mice, and ONOO^- could stimulate the development of AS. SMC-ECM with intact structure can be obtained in vitro by DOC treatment. Functionally, ONOO^- -mediated oxidization destroyed the three-dimensional structure of SMC-ECM proteins, affected SMC adhesion and migration and promoted the absorption efficiency of lipids while reducing the efflux of cholesterol. In addition, the expression of inflammation- and oxidative stress-related genes was significantly increased in ECM subjected to ONOO^- -mediated oxidization, thereby contributing to AS progression. ONOO^- -mediated oxidative modification of ECM aggravates AS by affecting the biological behavior of SMCs.

Pathogenic role of microRNAs in atherosclerotic ischemic stroke: Implications for diagnosis and therapy

Ischemic stroke resulting from atherosclerosis (particularly in the carotid artery) is one of the major subtypes of stroke and has a high incidence of death. Disordered lipid homeostasis, lipid deposition, local macrophage infiltration, smooth muscle cell proliferation, and plaque rupture are the main pathological processes of atherosclerotic ischemic stroke. Hepatocytes, macrophages, endothelial cells and vascular smooth muscle cells are the main cell types participating in these processes. By inhibiting the expression of the target genes in these cells, microRNAs play a key role in regulating lipid disorders and atherosclerotic ischemic stroke. In this article, we listed the microRNAs implicated in the pathology of atherosclerotic ischemic stroke and aimed to explain their pro- or antiatherosclerotic roles. Our article provides an update on the potential diagnostic use of miRNAs for detecting growing plaques and impending clinical events. Finally, we provide a perspective on the therapeutic use of local microRNA delivery and discuss the challenges for this potential therapy.

Major Vault Protein Prevents Atherosclerotic Plaque Destabilization by Suppressing Macrophage ASK1-JNK Signaling

BACKGROUND

Macrophages are implicated in atherosclerotic plaque instability by inflammation and degradation of extracellular matrix. However, the regulatory mechanisms driving these macrophage-associated processes are not well understood. Here, we aimed to identify the plaque destabilization-associated cytokines and signaling pathways in macrophages.

METHODS

The atherosclerotic models of myeloid-specific MVP (major vault protein) knockout mice and control mice were generated. Atherosclerotic instability, macrophage inflammatory signaling, and active cytokines released by macrophages were examined in vivo and in vitro by using cellular and molecular biological approaches.

RESULTS

MVP deficiency in myeloid cells exacerbated murine plaque instability by increasing production of both MMP (matrix metallopeptidase)-9 and proinflammatory cytokines in artery wall. Mechanistically, expression of MMP-9 was mediated via ASK1 (apoptosis signal-regulating kinase 1)-MKK-4 (mitogen-activated protein kinase kinase 4)-JNK (c-Jun N-terminal kinase) signaling in macrophages. MVP and its α-helical domain could bind with ASK1 and inhibit its dimerization and phosphorylation. A 62 amino acid peptide (MVP-[686-747]) in the α-helical domain of MVP showed a crucial role in preventing macrophage MMP-9 production and plaque instability.

CONCLUSIONS

MVP may act as an inhibitor for ASK1-JNK signaling-mediated MMP-9 production in macrophages and, thereby, attenuate unstable plaque formation. Our findings suggest that suppression of macrophage ASK1-JNK signaling may be a useful strategy antagonizing atherosclerotic diseases.

Interleukin 17, the double-edged sword in atherosclerosis

Cardiovascular diseases, including atherosclerosis, are the number one cause of death worldwide. These diseases have taken the place of pneumonia and other infectious diseases in the epidemiological charts. Thus, their importance should not be underestimated. Atherosclerosis is an inflammatory disease. Therefore, immunological signaling molecules and immune cells carry out a central role in its etiology. One of these signaling molecules is interleukin (IL)-17. This relatively newly discovered signaling molecule might have a dual role as acting both pro-atherogenic and anti-atherogenic depending on the situation. The majority of articles have discussed IL-17 and its action in atherosclerosis, and it may be a new target for the treatment of patients with this disease. In this review, the immunological basis of atherosclerosis with an emphasis on the role of IL-17 and a brief explanation of the role of IL-17 on atherosclerogenic disorders will be discussed.