Statins Disrupt Macrophage Rac1 Regulation Leading to Increased Atherosclerotic Plaque Calcification

The role of macrophage polarization in vascular calcification

Vascular calcification is an important factor in the high morbidity and mortality of Cardiovascular and cerebrovascular diseases. Vascular damage caused by calcification of the intima or media impairs the physiological function of the vascular wall. Inflammation is a central factor in the development of vascular calcification. Macrophages are the main inflammatory cells. Dynamic changes of macrophages with different phenotypes play an important role in the occurrence, progression and stability of calcification. This review focuses on macrophage polarization and the relationship between macrophages of different phenotypes and calcification environment, as well as the mechanism of interaction, it is considered that macrophages can promote vascular calcification by releasing inflammatory mediators and promoting the osteogenic transdifferentiation of smooth muscle cells and so on. In addition, several therapeutic strategies aimed at macrophage polarization for vascular calcification are described, which are of great significance for targeted treatment of vascular calcification.

Two sides of the same coin: Non-alcoholic fatty liver disease and atherosclerosis

The prevalence of non-alcoholic fatty liver disease (NAFLD) and atherosclerosis remain high, which is primarily due to widespread adoption of a western diet and sedentary lifestyle. NAFLD, together with advanced forms of this disease such as non-alcoholic steatohepatitis (NASH) and cirrhosis, are closely associated with atherosclerotic-cardiovascular disease (ASCVD). In this review, we discussed the association between NAFLD and atherosclerosis and expounded on the common molecular biomarkers underpinning the pathogenesis of both NAFLD and atherosclerosis. Furthermore, we have summarized the mode of function and potential clinical utility of existing drugs in the context of these diseases.

No evidence of coronary plaque stabilization by allopurinol in patients with acute coronary syndrome

BACKGROUND

Allopurinol, a xanthine inhibitor that lowers uric acid concentration, has been proven to reduce inflammation and oxidative stress in patients with cardiovascular disease. However, it is unknown whether these beneficial effects translate into favorable plaque modification in acute coronary syndromes (ACS). This study aimed to investigate whether allopurinol could improve coronary plaque stabilization using coronary computed tomography angiography (CCTA).

METHODS

This was a prospective, single-center, randomized, double-blind clinical trial began in March 2019. A total of 162 ACS patients aged 18-80 years with a blood level of high-sensitivity C-reactive protein (hsCRP) ​> ​2 ​mg/L were included. The subjects were randomly assigned in a 1:1 ratio to receive either allopurinol sustained-release capsules (at a dose of 0.25 ​g once daily) or placebo for 12 months. The plaque analysis was performed at CCTA. The primary efficacy endpoint was the change in low-attenuation plaque volume (LAPV) from baseline to the 12-month follow-up.

RESULTS

Among 162 patients, 54 in allopurinol group and 51 in placebo group completed the study. The median follow-up duration was 14 months in both groups. Compared with placebo, allopurinol therapy did not significantly alter LAPV (-13.4 ​± ​3.7 ​% vs. -17.8 ​± ​3.6 ​%, p ​= ​0.390), intermediate attenuation plaque volume (-16.1 ​± ​3.0 ​% vs. -16.2 ​± ​2.9 ​%, p ​= ​0.992), dense calcified plaque volume (12.2 ​± ​13.7 ​% vs. 9.7 ​± ​13.0 ​%, p ​= ​0.894), total atheroma volume (-15.2 ​± ​3.2 ​% vs. -16.4 ​± ​3.1 ​%, p ​= ​0.785), remodeling index (2.0 ​± ​3.9 ​% vs. 5.4 ​± ​3.8 ​%, p ​= ​0.536) or hsCRP levels (-73.6 [-91.6-17.9] % vs. -81.2 [-95.4-47.7] %, p ​= ​0.286).

CONCLUSIONS

Our findings suggest that allopurinol does not improve atherosclerotic plaque stability or inflammation in ACS.

Navigating the Statin Landscape: A Comprehensive Review of Stroke Prevention Strategies

This review provides a comprehensive exploration of the intricate relationship between statins and stroke prevention within the broader context of cardiovascular health. Delving into the mechanisms of statins, we elucidate their multifaceted contributions, ranging from cholesterol reduction to pleiotropic effects on the vascular system. Through a meticulous analysis of clinical trials, observational studies, and mechanistic investigations, we underscore the pivotal role of statins as integral components in the arsenal against strokes and associated cardiovascular events. The implications extend beyond statins as standalone interventions, emphasizing the potential for synergistic integration into broader stroke prevention strategies. Tailoring interventions to individual patient profiles and understanding the interplay with lifestyle modifications and other pharmacological approaches present opportunities for optimizing efficacy. Recommendations for future research advocate for continued exploration into the long-term effects of statin therapy, novel intervention combinations, and refined predictive models for personalized risk assessment. On a practical level, enhancing patient education, fostering interdisciplinary collaboration, and addressing barriers to medication adherence emerge as crucial aspects for real-world impact. In navigating this evolving landscape, the insights derived from this review contribute to informed decision-making and advancements in preventive cardiovascular medicine.

The Complex Mechanisms and the Potential Effects of Statins on Vascular Calcification: A Narrative Review

Vascular calcification (VC) is a complex process of calcium deposition on the arterial wall and atherosclerotic plaques and involves interaction between vascular smooth muscle cells, inflammatory and VC mediators. The latter are independent predictors of cardiovascular morbidity and mortality and potential targets of pharmaceutical therapy. This paper is a narrative review of the complex mechanisms of VC development and in this context the potential anti-atherosclerotic effects of statins. At the initial stages of atherosclerosis VC correlates with atherosclerosis burden and in the long-term with cardiovascular morbidity and mortality. A plethora of animal and clinical studies have proposed statins as the cornerstone of primary and secondary prevention of atherosclerotic cardiovascular disease. Based on coronary computed tomography data, high doses of statins may have negligible or even positive effects on the progression of coronary artery calcification. Growing data support an increase in atherosclerotic plaque calcification in peripheral arteries (e.g., carotids), after long-term, statin-therapy. Despite the paradox of increasing VC, those effects of statins have been associated with higher plaque stability, reducing the risk of consequent adverse events. Statins seem to promote a "favorable" atherosclerotic calcification, suppressing atherosclerotic lesion expansion and their vulnerability. More studies are required to clarify the underlying mechanisms.

Vascular calcification and cellular signaling pathways as potential therapeutic targets

Increased vascular calcification (VC) is observed in patients with cardiovascular diseases such as atherosclerosis, diabetes, and chronic kidney disease. VC is divided into three types according to its location: intimal, medial, and valvular. Various cellular signaling pathways are associated with VC, including the Wnt, mitogen-activated protein kinase, phosphatidylinositol-3 kinase/Akt, cyclic nucleotide-dependent protein kinase, protein kinase C, calcium/calmodulin-dependent kinase II, adenosine monophosphate-activated protein kinase/mammalian target of rapamycin, Ras homologous GTPase, apoptosis, Notch, and cytokine signaling pathways. In this review, we discuss the literature concerning the key cellular signaling pathways associated with VC and their role as potential therapeutic targets. Inhibitors to these pathways represent good candidates for use as potential therapeutic agents for the prevention and treatment of VC.

Beyond the Basics: Unraveling the Complexity of Coronary Artery Calcification

Coronary artery calcification (CAC) is mainly associated with coronary atherosclerosis, which is an indicator of coronary artery disease (CAD). CAC refers to the accumulation of calcium phosphate deposits, classified as micro- or macrocalcifications, that lead to the hardening and narrowing of the coronary arteries. CAC is a strong predictor of future cardiovascular events, such as myocardial infarction and sudden death. Our narrative review focuses on the pathophysiology of CAC, exploring its link to plaque vulnerability, genetic factors, and how race and sex can affect the condition. We also examined the connection between the gut microbiome and CAC, and the impact of genetic variants on the cellular processes involved in vascular calcification and atherogenesis. We aimed to thoroughly analyze the existing literature to improve our understanding of CAC and its potential clinical and therapeutic implications.

Improving statins production: From non-genetic strategies to genetic strategies

Statins are lipid-lowering drugs that selectively inhibit 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, effectively reducing cholesterol synthesis. With improved nutritional conditions, the demand for statins is increasing in the global market. The use of microbial cell factories for statin biosynthesis has become advantageous due to the rapid advancements in biotechnology. These approaches offer simple operation and easy separation of products. This review provides an overview the strategies for statins production via microbial cell factories, including both traditional fermentation culture (non-genetic) and modern synthetic biology manufacture (genetic). Firstly, the complex fermentation parameters and process control technology on submerged fermentation (SmF) and solid-state fermentation (SSF) are introduced in detail. The potential use of recoverable agricultural wastes/(biomass) as a fermentation substrate in SSF for statin production is emphasized. Additionally, metabolic engineering strategies for constructing robust engineering strains and directed evolution are also discussed. The review highlights the potential and challenges of using microbial cell factories for statin production, and aims to promote greener production modes for statins.

Apigenin inhibits macrophage pyroptosis through regulation of oxidative stress and the NF-κB pathway and ameliorates atherosclerosis

Pyroptosis plays an important role in inflammatory diseases such as viral hepatitis and atherosclerosis. Apigenin exhibits various bioactivities, particularly anti-inflammation, but its effect on pyroptosis remains unclear. The aim of this study is to investigate the effect of apigenin on pyroptosis and explore its potential against inflammatory diseases. THP-1 macrophages treated by lipopolysaccharides/adenosine 5'-triphosphate were used as the in vitro pyroptosis model. Western blot was used to detect the expression of NLRP3 inflammasome components and key regulators. Immunofluorescence was used to observe ROS production and intracellular location of p65. The potential of apigenin against inflammatory diseases was evaluated using atherosclerotic mice. Plaque progression was observed by pathological staining. Immunofluorescence was used to observe the expression of NLRP3 inflammasome components in plaques. The results showed that apigenin inhibited NLRP3 inflammasome activation. Apigenin reduced ROS overproduction and inhibited p65 nuclear translocation. Additionally, apigenin decreased the expression of NLRP3 inflammasome components in the plaque. Plaque progression was inhibited by apigenin. In conclusion, apigenin exhibited a preventive effect on macrophage pyroptosis by reducing oxidative stress and inhibiting the NF-κB pathway. Apigenin may alleviate atherosclerosis at least partially by inhibiting macrophage pyroptosis. These findings suggest apigenin to be a promising therapeutic agent for inflammatory diseases.

Targeting small GTPases: emerging grasps on previously untamable targets, pioneered by KRAS

Small GTPases including Ras, Rho, Rab, Arf, and Ran are omnipresent molecular switches in regulating key cellular functions. Their dysregulation is a therapeutic target for tumors, neurodegeneration, cardiomyopathies, and infection. However, small GTPases have been historically recognized as "undruggable". Targeting KRAS, one of the most frequently mutated oncogenes, has only come into reality in the last decade due to the development of breakthrough strategies such as fragment-based screening, covalent ligands, macromolecule inhibitors, and PROTACs. Two KRAS^G12C covalent inhibitors have obtained accelerated approval for treating KRAS^G12C mutant lung cancer, and allele-specific hotspot mutations on G12D/S/R have been demonstrated as viable targets. New methods of targeting KRAS are quickly evolving, including transcription, immunogenic neoepitopes, and combinatory targeting with immunotherapy. Nevertheless, the vast majority of small GTPases and hotspot mutations remain elusive, and clinical resistance to G12C inhibitors poses new challenges. In this article, we summarize diversified biological functions, shared structural properties, and complex regulatory mechanisms of small GTPases and their relationships with human diseases. Furthermore, we review the status of drug discovery for targeting small GTPases and the most recent strategic progress focused on targeting KRAS. The discovery of new regulatory mechanisms and development of targeting approaches will together promote drug discovery for small GTPases.

Cardiovascular Calcification Heterogeneity in Chronic Kidney Disease

Patients with chronic kidney disease (CKD) exhibit tremendously elevated risk for cardiovascular disease, particularly ischemic heart disease, due to premature vascular and cardiac aging and accelerated ectopic calcification. The presence of cardiovascular calcification associates with increased risk in patients with CKD. Disturbed mineral homeostasis and diverse comorbidities in these patients drive increased systemic cardiovascular calcification in different manifestations with diverse clinical consequences, like plaque instability, vessel stiffening, and aortic stenosis. This review outlines the heterogeneity in calcification patterning, including mineral type and location and potential implications on clinical outcomes. The advent of therapeutics currently in clinical trials may reduce CKD-associated morbidity. Development of therapeutics for cardiovascular calcification begins with the premise that less mineral is better. While restoring diseased tissues to a noncalcified homeostasis remains the ultimate goal, in some cases, calcific mineral may play a protective role, such as in atherosclerotic plaques. Therefore, developing treatments for ectopic calcification may require a nuanced approach that considers individual patient risk factors. Here, we discuss the most common cardiac and vascular calcification pathologies observed in CKD, how mineral in these tissues affects function, and the potential outcomes and considerations for therapeutic strategies that seek to disrupt the nucleation and growth of mineral. Finally, we discuss future patient-specific considerations for treating cardiac and vascular calcification in patients with CKD-a population in need of anticalcification therapies.

CD163+ macrophages restrain vascular calcification, promoting the development of high-risk plaque

Vascular calcification (VC) is concomitant with atherosclerosis, yet it remains uncertain why rupture-prone high-risk plaques do not typically show extensive calcification. Intraplaque hemorrhage (IPH) deposits erythrocyte-derived cholesterol, enlarging the necrotic core and promoting high-risk plaque development. Pro-atherogenic CD163+ alternative macrophages engulf hemoglobin:haptoglobin (HH) complexes at IPH sites. However, their role in VC has never been examined to our knowledge. Here we show, in human arteries, the distribution of CD163+ macrophages correlated inversely with VC. In vitro experiments using vascular smooth muscle cells (VSMCs) cultured with HH-exposed human macrophage - M(Hb) - supernatant reduced calcification, while arteries from ApoE-/- CD163-/- mice showed greater VC. M(Hb) supernatant-exposed VSMCs showed activated NF-κB, while blocking NF-κB attenuated the anticalcific effect of M(Hb) on VSMCs. CD163+ macrophages altered VC through NF-κB-induced transcription of hyaluronan synthase (HAS), an enzyme that catalyzes the formation of the extracellular matrix glycosaminoglycan, hyaluronan, within VSMCs. M(Hb) supernatants enhanced HAS production in VSMCs, while knocking down HAS attenuated its anticalcific effect. NF-κB blockade in ApoE-/- mice reduced hyaluronan and increased VC. In human arteries, hyaluronan and HAS were increased in areas of CD163+ macrophage presence. Our findings highlight an important mechanism by which CD163+ macrophages inhibit VC through NF-κB-induced HAS augmentation and thus promote the high-risk plaque development.

Vascular calcification: Molecular mechanisms and therapeutic interventions

Vascular calcification (VC) is recognized as a pathological vascular disorder associated with various diseases, such as atherosclerosis, hypertension, aortic valve stenosis, coronary artery disease, diabetes mellitus, as well as chronic kidney disease. Therefore, it is a life-threatening state for human health. There were several studies targeting mechanisms of VC that revealed the importance of vascular smooth muscle cells transdifferentiating, phosphorous and calcium milieu, as well as matrix vesicles on the progress of VC. However, the underlying molecular mechanisms of VC need to be elucidated. Though there is no acknowledged effective therapeutic strategy to reverse or cure VC clinically, recent evidence has proved that VC is not a passive irreversible comorbidity but an active process regulated by many factors. Some available approaches targeting the underlying molecular mechanism provide promising prospects for the therapy of VC. This review aims to summarize the novel findings on molecular mechanisms and therapeutic interventions of VC, including the role of inflammatory responses, endoplasmic reticulum stress, mitochondrial dysfunction, iron homeostasis, metabolic imbalance, and some related signaling pathways on VC progression. We also conclude some recent studies on controversial interventions in the clinical practice of VC, such as calcium channel blockers, renin-angiotensin system inhibitions, statins, bisphosphonates, denosumab, vitamins, and ion conditioning agents.

Molecular Mechanisms of Vascular Health: Insights From Vascular Aging and Calcification

Cardiovascular disease is the most common cause of death worldwide, especially beyond the age of 65 years, with the vast majority of morbidity and mortality due to myocardial infarction and stroke. Vascular pathology stems from a combination of genetic risk, environmental factors, and the biologic changes associated with aging. The pathogenesis underlying the development of vascular aging, and vascular calcification with aging, in particular, is still not fully understood. Accumulating data suggests that genetic risk, likely compounded by epigenetic modifications, environmental factors, including diabetes and chronic kidney disease, and the plasticity of vascular smooth muscle cells to acquire an osteogenic phenotype are major determinants of age-associated vascular calcification. Understanding the molecular mechanisms underlying genetic and modifiable risk factors in regulating age-associated vascular pathology may inspire strategies to promote healthy vascular aging. This article summarizes current knowledge of concepts and mechanisms of age-associated vascular disease, with an emphasis on vascular calcification.

Pitavastatin Induces Apoptosis of Cutaneous Squamous Cell Carcinoma Cells through Geranylgeranyl Pyrophosphate-Dependent c-Jun N-Terminal Kinase Activation

BACKGROUND

Pitavastatin is a cholesterol-lowering drug and is widely used clinically. In addition to this effect, pitavastatin has shown the potential to induce apoptosis in cutaneous squamous cell carcinoma (SCC) cells.

OBJECTIVE

The purpose of this study is to investigate the effects and possible action mechanisms of pitavastatin.

METHODS

SCC cells (SCC12 and SCC13 cells) were treated with pitavastatin, and induction of apoptosis was confirmed by Western blot. To examine whether pitavastatin-induced apoptosis is related to a decrease in the amount of intermediate mediators in the cholesterol synthesis pathway, the changes in pitavastatin-induced apoptosis after supplementation with mevalonate, squalene, geranylgeranyl pyrophosphate (GGPP) and dolichol were investigated.

RESULTS

Pitavastatin dose-dependently induced apoptosis of cutaneous SCC cells, but the viability of normal keratinocytes was not affected by pitavastatin at the same concentrations. In supplementation experiments, pitavastatin-induced apoptosis was inhibited by the addition of mevalonate or downstream metabolite GGPP. As a result of examining the effect on intracellular signaling, pitavastatin decreased Yes1 associated transcriptional regulator and Ras homolog family member A and increased Rac family small GTPase 1 and c-Jun N-terminal kinase (JNK) activity. All these effects of pitavastatin on signaling molecules were restored when supplemented with either mevalonate or GGPP. Furthermore, pitavastatin-induced apoptosis of cutaneous SCC cells was inhibited by a JNK inhibitor.

CONCLUSION

These results suggest that pitavastatin induces apoptosis of cutaneous SCC cells through GGPP-dependent JNK activation.

Targeting Mast Cells in Allergic Disease: Current Therapies and Drug Repurposing

The incidence of allergic disease has grown tremendously in the past three generations. While current treatments are effective for some, there is considerable unmet need. Mast cells are critical effectors of allergic inflammation. Their secreted mediators and the receptors for these mediators have long been the target of allergy therapy. Recent drugs have moved a step earlier in mast cell activation, blocking IgE, IL-4, and IL-13 interactions with their receptors. In this review, we summarize the latest therapies targeting mast cells as well as new drugs in clinical trials. In addition, we offer support for repurposing FDA-approved drugs to target mast cells in new ways. With a multitude of highly selective drugs available for cancer, autoimmunity, and metabolic disorders, drug repurposing offers optimism for the future of allergy therapy.

Evolving Role of Calcium Density in Coronary Artery Calcium Scoring and Atherosclerotic Cardiovascular Disease Risk

Coronary artery calcium (CAC) is a specific marker of coronary atherosclerosis that can be used to measure calcified subclinical atherosclerotic burden. The Agatston method is the most widely used scoring algorithm for quantifying CAC and is expressed as the product of total calcium area and a quantized peak calcium density weighting factor defined by the calcification attenuation in HU on noncontrast computed tomography. Calcium density has emerged as an important area of inquiry because the Agatston score is upweighted based on the assumption that peak calcium density and atherosclerotic cardiovascular disease (ASCVD) risk are positively correlated. However, recent evidence demonstrates that calcium density is inversely associated with lesion vulnerability and ASCVD risk in population-based cohorts when accounting for age and plaque area. Here, we review calcium density by focusing on 3 main areas: 1) CAC scan acquisition parameters; 2) pathophysiology of calcified plaques; and 3) epidemiologic evidence relating calcium density to ASCVD outcomes. Through this process, we hope to provide further insight into the evolution of CAC scoring on noncontrast computed tomography.

Interactions Between Immunomodulatory Biomaterials and Immune Microenvironment: Cues for Immunomodulation Strategies in Tissue Repair

The foreign body response (FBR) caused by biomaterials can essentially be understood as the interaction between the immune microenvironment and biomaterials, which has severely impeded the application of biomaterials in tissue repair. This concrete interaction occurs via cells and bioactive substances, such as proteins and nucleic acids. These cellular and molecular interactions provide important cues for determining which element to incorporate into immunomodulatory biomaterials (IMBs), and IMBs can thus be endowed with the ability to modulate the FBR and repair damaged tissue. In terms of cellular, IMBs are modified to modulate functions of immune cells, such as macrophages and mast cells. In terms of bioactive substances, proteins and nucleic acids are delivered to influence the immune microenvironment. Meanwhile, IMBs are designed with high affinity for spatial targets and the ability to self-adapt over time, which allows for more efficient and intelligent tissue repair. Hence, IMB may achieve the perfect functional integration in the host, representing a breakthrough in tissue repair and regeneration medicine.

Rac1 mediates cadherin-11 induced cellular pathogenic processes in aortic valve calcification

BACKGROUND

Calcific aortic valve disease (CAVD), a major cause for surgical aortic valve replacement, currently lacks available pharmacological treatments. Cadherin-11 (Cad11), a promising therapeutic target, promotes aortic valve calcification in vivo, but direct Cad11 inhibition in clinical trials has been unsuccessful. Targeting of downstream Cad11 effectors instead may be clinically useful; however, the downstream effectors that mediate Cad11-induced aortic valve cellular pathogenesis have not been investigated.

APPROACH AND RESULTS

Immunofluorescence of calcified human aortic valves revealed that GTP-Rac1 is highly upregulated in calcified leaflets and is 2.15 times more co-localized with Cad11 in calcified valves than GTP-RhoA. Using dominant negative mutants in porcine aortic valve interstitial cells (PAVICs), we show that Cad11 predominantly regulates Runx2 nuclear localization via Rac1. Rac1-GEF inhibition via NSC23766 effectively reduces calcification in ex vivo porcine aortic valve leaflets treated with osteogenic media by 2.8-fold and also prevents Cad11-induced cell migration, compaction, and calcification in PAVICs. GTP-Rac1 and Trio, a known Cad11 binding partner and Rac1-GEF, are significantly upregulated in Nfatc1Cre; R26-Cad11Tg/Tg (Cad11 OX) mice that conditionally overexpress Cad11 in the heart valves by 3.1-fold and 6.3-fold, respectively. Finally, we found that the Trio-specific Rac1-GEF inhibitor, ITX3, effectively prevents Cad11-induced calcification and Runx2 induction in osteogenic conditions.

CONCLUSION

Here we show that Cad11 induces many cellular pathogenic processes via Rac1 and that Rac1 inhibition effectively prevents many Cad11-induced aortic disease phenotypes. These findings highlight the therapeutic potential of blocking Rac1-GEFs in CAVD.

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.

In Vivo Pravastatin Treatment Reverses Hypercholesterolemia Induced Mitochondria-Associated Membranes Contact Sites, Foam Cell Formation, and Phagocytosis in Macrophages

Statins are successful drugs used to treat hypercholesterolemia, a primary cause of atherosclerosis. In this work, we investigated how hypercholesterolemia and pravastatin treatment impact macrophage and mitochondria functions, the key cell involved in atherogenesis. By comparing bone marrow-derived macrophages (BMDM) of wild-type (WT) and LDL receptor knockout (LDLr^−/−) mice, we observed hypercholesterolemia increased the number of contact sites at mitochondria-associated endoplasmic reticulum (ER) membranes (MAMs), enhanced mitochondrial hydrogen peroxide release, altered the gene expression of inflammatory markers, and increased oxidized LDL (ox-LDL) uptake and phagocytic activity. Three months of in vivo pravastatin treatment of LDLr^−/− mice reversed the number of contact sites at the MAM, ox-LDL uptake, and phagocytosis in LDLr^−/− BMDM. Additionally, pravastatin increased BMDM mitochondrial network branching. In peritoneal macrophages (PMs), hypercholesterolemia did not change MAM stability, but stimulated hydrogen peroxide production and modulated gene expression of pro- and anti-inflammatory markers. It also increased mitochondrial branching degree and had no effects on ox-LDL uptake and phagocytosis in PM. Pravastatin treatment increased superoxide anion production and changed inflammation-related gene expression in LDLr^−/− PM. In addition, pravastatin increased markedly the expression of the mitochondrial dynamics-related genes Mfn2 and Fis1 in both macrophages. In summary, our results show that hypercholesterolemia and pravastatin treatment affect macrophage mitochondria network structure as well as their interaction with the endoplasmic reticulum (ER). These effects impact on macrophage conversion rates to foam cell and macrophage phagocytic capacity. These findings associate MAM stability changes with known mechanisms involved in atherosclerosis progression and resolution.

Underappreciated roles for Rho GDP dissociation inhibitors (RhoGDIs) in cell function: Lessons learned from the pancreatic islet β-cell

Rho subfamily of G proteins (e.g., Rac1) have been implicated in glucose-stimulated insulin secretion from the pancreatic β-cell. Interestingly, metabolic stress (e.g., chronic exposure to high glucose) results in sustained activation of Rac1 leading to increased oxidative stress, impaired insulin secretion and β-cell dysfunction. Activation-deactivation of Rho G proteins is mediated by three classes of regulatory proteins, namely the guanine nucleotide exchange factors (GEFs), which facilitate the conversion of inactive G proteins to their active conformations; the GTPase-activating proteins (GAPs), which convert the active G proteins to their inactive forms); and the GDP-dissociation inhibitors (GDIs), which prevent the dissociation of GDP from G proteins. Contrary to a large number of GEFs (82 members) and GAPs (69 members), only three members of RhoGDIs (RhoGDIα, RhoGDIβ and RhoGDIγ) are expressed in mammalian cells.Even though relatively smaller in number, the GDIs appear to play essential roles in G protein function (e.g., subcellular targeting) for effector activation and cell regulation. Emerging evidence also suggests that the GDIs are functionally regulated via post-translational modification (e.g., phosphorylation) and by lipid second messengers, lipid kinases and lipid phosphatases. We highlight the underappreciated regulatory roles of RhoGDI-Rho G protein signalome in islet β-cell function in health and metabolic stress. Potential knowledge gaps in the field, and directions for future research for the identification of novel therapeutic targets to loss of functional β-cell mass under the duress of metabolic stress are highlighted.

Macrophage IL-1β promotes arteriogenesis by autocrine STAT3- and NF-κB-mediated transcription of pro-angiogenic VEGF-A

Peripheral artery disease (PAD) leads to considerable morbidity, yet strategies for therapeutic angiogenesis fall short of being impactful. Inflammatory macrophage subsets play an important role in orchestrating post-developmental angiogenesis, but the underlying mechanisms are unclear. Here, we find that macrophage VEGF-A expression is dependent upon the potent inflammatory cytokine, IL-1β. IL-1β promotes pro-angiogenic VEGF-A₁₆₅a isoform transcription via activation and promoter binding of STAT3 and NF-κB, as demonstrated by gene-deletion, gain-of-function, inhibition, and chromatin immunoprecipitation assays. Conversely, IL-1β-deletion or inhibition of STAT3 or NF-κB increases anti-angiogenic VEGF-A₁₆₅b isoform expression, indicating IL-1β signaling may also direct splice variant selection. In an experimental PAD model of acute limb ischemia, macrophage IL-1β expression is required for pro-angiogenic VEGF-A expression and for VEGF-A-induced blood flow recovery via angio- or arteriogenesis. Though further study is needed, macrophage IL-1β-dependent transcription of VEGF-A via STAT3 and NF-κB may have potential to therapeutically promote angiogenesis in the setting of PAD.

Mantsounga et al. show inflammatory macrophage IL-1β expression to be required for pro-angiogenic VEGF-A expression and consequent post-developmental angio- or arteriogenesis in an experimental model of peripheral artery disease. Autocrine IL-1β signaling promotes transcription of pro-angiogenic VEGF-A₁₆₅a isoform expression relative to anti-angiogenic isoform, VEGF-A₁₆₅b, through activation of STAT3 and NF-κB.

Statins and Bempedoic Acid: Different Actions of Cholesterol Inhibitors on Macrophage Activation

Statins represent the most prescribed class of drugs for the treatment of hypercholesterolemia. Effects that go beyond lipid-lowering actions have been suggested to contribute to their beneficial pharmacological properties. Whether and how statins act on macrophages has been a matter of debate. In the present study, we aimed at characterizing the impact of statins on macrophage polarization and comparing these to the effects of bempedoic acid, a recently registered drug for the treatment of hypercholesterolemia, which has been suggested to have a similar beneficial profile but fewer side effects. Treatment of primary murine macrophages with two different statins, i.e., simvastatin and cerivastatin, impaired phagocytotic activity and, concurrently, enhanced pro-inflammatory responses upon short-term lipopolysaccharide challenge, as characterized by an induction of tumor necrosis factor (TNF), interleukin (IL) 1β, and IL6. In contrast, no differences were observed under long-term inflammatory (M1) or anti-inflammatory (M2) conditions, and neither inducible NO synthase (iNOS) expression nor nitric oxide production was altered. Statin treatment led to extracellular-signal regulated kinase (ERK) activation, and the pro-inflammatory statin effects were abolished by ERK inhibition. Bempedoic acid only had a negligible impact on macrophage responses when compared with statins. Taken together, our data point toward an immunomodulatory effect of statins on macrophage polarization, which is absent upon bempedoic acid treatment.

Association of Statin Treatment With Progression of Coronary Atherosclerotic Plaque Composition

Importance

The density of atherosclerotic plaque forms the basis for categorizing calcified and noncalcified morphology of plaques.

Objective

To assess whether alterations in plaque across a range of density measurements provide a more detailed understanding of atherosclerotic disease progression.

Design, Setting, and Participants

This cohort study enrolled 857 patients who underwent serial coronary computed tomography angiography 2 or more years apart and had quantitative measurements of coronary plaques throughout the entire coronary artery tree. The study was conducted from 2013 to 2016 at 13 sites in 7 countries.

Main Outcomes and Measures

The main outcome was progression of plaque composition of individual coronary plaques. Six plaque composition types were defined on a voxel-level basis according to the plaque attenuation (expressed in Hounsfield units [HU]): low attenuation (-30 to 75 HU), fibro-fatty (76-130 HU), fibrous (131-350 HU), low-density calcium (351-700 HU), high-density calcium (701-1000 HU), and 1K (>1000 HU). The progression rates of these 6 compositional plaque types were evaluated according to the interaction between statin use and baseline plaque volume, adjusted for risk factors and time interval between scans. Plaque progression was also examined based on baseline calcium density. Analysis was performed among lesions matched at baseline and follow-up. Data analyses were conducted from August 2019 through March 2020.

Results

In total, 2458 coronary lesions in 857 patients (mean [SD] age, 62.1 [8.7] years; 540 [63.0%] men; 548 [63.9%] received statin therapy) were included. Untreated coronary lesions increased in volume over time for all 6 compositional types. Statin therapy was associated with volume decreases in low-attenuation plaque (β, -0.02; 95% CI, -0.03 to -0.01; P = .001) and fibro-fatty plaque (β, -0.03; 95% CI, -0.04 to -0.02; P < .001) and greater progression of high-density calcium plaque (β, 0.02; 95% CI, 0.01-0.03; P < .001) and 1K plaque (β, 0.02; 95% CI, 0.01-0.03; P < .001). When analyses were restricted to lesions without low-attenuation plaque or fibro-fatty plaque at baseline, statin therapy was not associated with a change in overall calcified plaque volume (β, -0.03; 95% CI, -0.08 to 0.02; P = .24) but was associated with a transformation toward more dense calcium. Interaction analysis between baseline plaque volume and calcium density showed that more dense coronary calcium was associated with less plaque progression.

Conclusions and Relevance

The results suggest an association of statin use with greater rates of transformation of coronary atherosclerosis toward high-density calcium. A pattern of slower overall plaque progression was observed with increasing density. All findings support the concept of reduced atherosclerotic risk with increased densification of calcium.

Rac GTPase Signaling in Immune-Mediated Mechanisms of Atherosclerosis

Coronary artery disease caused by atherosclerosis is a major cause of morbidity and mortality around the world. Data from preclinical and clinical studies support the belief that atherosclerosis is an inflammatory disease that is mediated by innate and adaptive immune signaling mechanisms. This review sought to highlight the role of Rac-mediated inflammatory signaling in the mechanisms driving atherosclerotic calcification. In addition, current clinical treatment strategies that are related to targeting hypercholesterolemia as a critical risk factor for atherosclerotic vascular disease are addressed in relation to the effects on Rac immune signaling and the implications for the future of targeting immune responses in the treatment of calcific atherosclerosis.

Atorvastatin Promotes Macrocalcification, But Not Microcalcification in Atherosclerotic Rabbits: An 18F-NaF PET/CT Study

INTRODUCTION

Our study aimed to investigate the effect of atorvastatin on plaque calcification by matching the results obtained by 18F-sodium fluoride (18F-NaF) positron emission tomography (PET)/computed tomography (CT) with data from histologic sections.

METHODS AND RESULTS

The rabbits were divided into 2 groups as follows: an atherosclerosis group (n = 10) and an atorvastatin group (n = 10). All rabbits underwent an abdominal aortic operation and were fed a high-fat diet to induce atherosclerosis. Plasma samples were used to analyze serum inflammation markers and blood lipid levels. 18F-NaF PET/CT scans were performed twice. The plaque area, macrophage number and calcification were measured, and the data from the pathological sections were matched with the 18F-NaF PET/CT scan results. The mean standardized uptake value (0.725 ± 0.126 vs. 0.603 ± 0.071, P < 0.001) and maximum standardized uptake value (1.024 ± 0.116 vs. 0.854 ± 0.091, P < 0.001) significantly increased in the atherosclerosis group, but only slightly increased in the atorvastatin group (0.616 ± 0.103 vs. 0.613 ± 0.094, P = 0.384; 0.853 ± 0.099 vs.0.837 ± 0.089, P < 0.001, respectively). The total calcium density was significantly increased in rabbits treated with atorvastatin compared with rabbits not treated with atorvastatin (1.64 ± 0.90 vs. 0.49 ± 0.35, P < 0.001), but the microcalcification level was significantly lower. There were more microcalcification deposits in the areas with increased radioactive uptake of 18F-NaF.

CONCLUSIONS

Our study suggests that the anti-inflammatory activity of atorvastatin may promote macrocalcification but not microcalcification within atherosclerotic plaques. 18F-NaF PET/CT can detect plaque microcalcifications.

Pioglitazone combined with atorvastatin promotes plaque stabilization in a rabbit model

OBJECTIVE

It is not yet clear whether plaque inflammation and cardiovascular events are reduced further when pioglitazone and atorvastatin are combined. Our study aimed to determine whether pioglitazone combined with atorvastatin can restrain the progression of atherosclerosis and promote plaque stabilization in a rabbit model.

METHOD AND RESULT

Thirty rabbits were randomly divided into an atherosclerosis group, an atorvastatin group, and an atorvastatin plus pioglitazone group. The atherosclerosis model was induced using balloon injury and feeding a high-fat diet. Plasma samples were then used to analyze glucose, triglycerides (TG), high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), high-sensitivity C-reactive protein (hs-CRP), and matrix metalloproteinase-9 (MMP-9). The area percentage of atherosclerotic plaques was analyzed by hematoxylin-eosin staining. The relative reductions in TG and LDL-C and the increase in HDL-C levels were significantly greater in the combination therapy group than in the atorvastatin monotherapy group (TG: -33.60 ± 7.17% vs -24.16 ± 8.04%, p < 0.001; LDL-C: -42.89 ± 1.63% vs -37.13 ± 1.35%, p < 0.001; and HDL-C: 25.18 ± 5.53% vs 10.43 ± 6.31%, p < 0.001). The relative reductions in hs-CRP and MMP-9 levels were significantly greater in the combination therapy group than in the atorvastatin monotherapy group (-69.38 ± 1.06% vs-53.73 ± 1.92%, p < 0.001; -32.77 ± 2.49% vs -13.36 ± 1.66%, p < 0.001). The area percentage of atherosclerotic plaques was significantly smaller in the atorvastatin group (47.75%, p < 0.05) and in the atorvastatin plus pioglitazone group (22.57%, p < 0.05) than in the atherosclerosis group (84.08%, p < 0.05).

CONCLUSION

We can thus conclude that the combination treatment of atorvastatin and pioglitazone provided additive benefits on inflammatory parameters and lipid metabolism. Pioglitazone combined with atorvastatin can further restrain the progression of atherosclerosis and promote plaque stabilization in a rabbit model.

Inhibition of Rac1 GTPase Decreases Vascular Oxidative Stress, Improves Endothelial Function, and Attenuates Atherosclerosis Development in Mice

Aims: Oxidative stress and inflammation contribute to atherogenesis. Rac1 GTPase regulates pro-oxidant NADPH oxidase activity, reactive oxygen species (ROS) formation, actin cytoskeleton organization and monocyte adhesion. We investigated the vascular effects of pharmacological inhibition of Rac1 GTPase in mice.

Methods and Results: We treated wild-type and apolipoprotein E-deficient (ApoE^−/−) mice with Clostridium sordellii lethal toxin (LT), a Rac1 inhibitor, and assessed vascular oxidative stress, expression and activity of involved proteins, endothelial function, macrophage infiltration, and atherosclerosis development. LT-treated wild-type mice displayed decreased vascular NADPH oxidase activity and ROS production. Therapeutic LT doses had no impact on behavior, food intake, body weight, heart rate, blood pressure, vascular and myocardial function, differential blood count, and vascular permeability. ApoE^−/− mice were fed a cholesterol-rich diet and were treated with LT or vehicle. LT treatment led to decreased aortic Rac1 GTPase activity, NADPH oxidase activity and ROS production, but had no impact on expression and membrane translocation of NADPH oxidase subunits and RhoA GTPase activity. LT-treated mice showed improved aortic endothelium-dependent vasodilation, attenuated atherosclerotic lesion formation and reduced macrophage infiltration of atherosclerotic plaques. Concomitant treatment of cholesterol-fed ApoE^−/− mice with LT, the specific synthetic Rac1 inhibitor NSC 23766 or simvastatin comparably reduced aortic Rac1 activity, NADPH oxidase activity, oxidative stress, endothelial dysfunction, atherosclerosis development, and macrophage infiltration.

Conclusions: These findings identify an important role of the small GTPase Rac1 in atherogenesis and provide a potential target for anti-atherosclerotic therapy.

Coronary Artery Disease Genetics Enlightened by Genome-Wide Association Studies

Many cardiovascular diseases are facilitated by strong inheritance. For example, large-scale genetic studies identified hundreds of genomic loci that affect the risk of coronary artery disease. At each of these loci, common variants are associated with disease risk with robust statistical evidence but individually small effect sizes. Only a minority of candidate genes found at these loci are involved in the pathophysiology of traditional risk factors, but experimental research is making progress in identifying novel, and, in part, unexpected mechanisms. Targets identified by genome-wide association studies have already led to the development of novel treatments, specifically in lipid metabolism. This review summarizes recent genetic and experimental findings in this field. In addition, the development and possible clinical usefulness of polygenic risk scores in risk prediction and individualization of treatment, particularly in lipid metabolism, are discussed.

Statin Effects on Vascular Calcification: Microarchitectural Changes in Aortic Calcium Deposits in Aged Hyperlipidemic Mice

[Figure: see text].

Emerging views of statin pleiotropy and cholesterol lowering

Over the past four decades, no class of drugs has had more impact on cardiovascular health than the HMC-CoA reductase inhibitors or statins. Developed as potent lipid-lowering agents, statins were later shown to reduce morbidity and mortality of patients who are at risk for cardiovascular disease. However, retrospective analyses of some of these clinical trials have uncovered some aspects of their clinical benefits that may be additional to their lipid-lowering effects. Such "pleiotropic" effects of statins garnered intense interest and debate over its contribution to cardiovascular risk reduction. This review will provide a brief background of statin pleiotropy, assess the available clinical evidence for and against their non-lipid-lowering benefits, and propose future research directions in this field.

Rho GTPase regulation of reactive oxygen species generation and signalling in platelet function and disease

Platelets are master regulators and effectors of haemostasis with increasingly recognized functions as mediators of inflammation and immune responses. The Rho family of GTPase members Rac1, Cdc42 and RhoA are known to be major components of the intracellular signalling network critical to platelet shape change and morphological dynamics, thus playing a major role in platelet spreading, secretion and thrombus formation. Initially linked to the regulation of actomyosin contraction and lamellipodia formation, recent reports have uncovered non-canonical functions of platelet RhoGTPases in the regulation of reactive oxygen species (ROS), where intrinsically generated ROS modulate platelet function and contribute to thrombus formation. Platelet RhoGTPases orchestrate oxidative processes and cytoskeletal rearrangement in an interconnected manner to regulate intracellular signalling networks underlying platelet activity and thrombus formation. Herein we review our current knowledge of the regulation of platelet ROS generation by RhoGTPases and their relationship with platelet cytoskeletal reorganization, activation and function.

Coronary Artery Calcification Under Statin Therapy and Its Effect on Cardiovascular Outcomes: A Systematic Review and Meta-Analysis

Objective: To compare Agatston scores between patients without statin therapy and those under standard and intensive statin therapy and to systematically review the relationship between coronary artery calcification (CAC) progression under statin therapy and cardiovascular outcomes.

Methods: Literature search was conducted across databases. Randomized controlled trials and observational studies that reported Agatston scores at baseline and follow-up from patients with and without statin therapy were included. A systematic review and meta-analysis was conducted.

Results: Seven studies were subjected to qualitative and quantitative analyses. Agatston scores in all groups were increased at follow-up. Meta-analysis of data from the included studies revealed an insignificantly lower CAC score at follow-up in the experimental groups. Subgroup analysis showed that statins slowed down CAC progression mildly but with statistical significance in population with baseline CAC score >400 in the experimental groups (P = 0.009). Despite that calcification progressors had worse cardiovascular outcome than did non-progressors, it appeared that baseline CAC score had more decisive effects on cardiovascular outcomes. CAC progression under statin therapy did not increase cardiovascular risk, although more supportive data are needed.

Conclusion: Statins do not reduce or enhance CAC as measured by Agatston score in asymptomatic populations at high risk of cardiovascular diseases, but seem to slow down CAC progression. Although our result was robust, it was restricted by small sample size and relatively short follow-up period. Further studies on the relationship between CAC progression under statin therapy and cardiovascular outcomes are needed.

Depletion of essential isoprenoids and ER stress induction following acute liver-specific deletion of HMG-CoA reductase

HMG-CoA reductase (Hmgcr) is the rate-limiting enzyme in the mevalonate pathway and is inhibited by statins. In addition to cholesterol, Hmgcr activity is also required for synthesizing nonsterol isoprenoids, such as dolichol, ubiquinone, and farnesylated and geranylgeranylated proteins. Here, we investigated the effects of Hmgcr inhibition on nonsterol isoprenoids in the liver. We have generated new genetic models to acutely delete genes in the mevalonate pathway in the liver using AAV-mediated delivery of Cre-recombinase (AAV-Cre) or CRISPR/Cas9 (AAV-CRISPR). The genetic deletion of Hmgcr by AAV-Cre resulted in extensive hepatocyte apoptosis and compensatory liver regeneration. At the biochemical level, we observed decreased levels of sterols and depletion of the nonsterol isoprenoids, dolichol and ubiquinone. At the cellular level, Hmgcr-null hepatocytes showed ER stress and impaired N-glycosylation. We further hypothesized that the depletion of dolichol, essential for N-glycosylation, could be responsible for ER stress. Using AAV-CRISPR, we somatically disrupted dehydrodolichyl diphosphate synthase subunit (Dhdds), encoding a branch point enzyme required for dolichol biosynthesis. Dhdds-null livers showed ER stress and impaired N-glycosylation, along with apoptosis and regeneration. Finally, the combined deletion of Hmgcr and Dhdds synergistically exacerbated hepatocyte ER stress. Our data show a critical role for mevalonate-derived dolichol in the liver and suggest that dolichol depletion is at least partially responsible for ER stress and apoptosis upon potent Hmgcr inhibition.

Age-associated arterial calcification: the current pursuit of aggravating and mitigating factors

PURPOSE OF REVIEW

The incidence of arterial calcification increases with age, can occur independently of atherosclerosis and hyperlipidemia, contributes to vessel stiffening, and is associated with adverse cardiovascular outcomes. Here, we provide an up-to-date review of how aging leads to arterial calcification and discuss potential therapies.

RECENT FINDINGS

Recent research suggests that mitochondrial dysfunction (impaired efficiency of the respiratory chain, increased reactive oxygen species production, and a high mutation rate of mitochondrial DNA), cellular senescence, ectonucleotidases, and extrinsic factors such as hyperglycemia promote age-determined calcification. We discuss the future potential impact of antilipidemics, senolytics, and poly(ADP-ribose)polymerases inhibitors on age-associated arterial calcification.

SUMMARY

Understanding how mechanisms of aging lead to arterial calcification will allow us to pinpoint prospective strategies to mitigate arterial calcification, even after the effects of aging have already begun to occur.

Evaluation of active Rac1 levels in cancer cells: A case of misleading conclusions from immunofluorescence analysis

A large number of aggressive cancer cell lines display elevated levels of activated Rac1, a small GTPase widely implicated in cytoskeleton reorganization, cell motility, and metastatic dissemination. A commonly accepted methodological approach for detecting Rac1 activation in cancer cells involves the use of a conformation-sensitive antibody that detects the active (GTP-bound) Rac1 without interacting with the GDP-bound inactive form. This antibody has been extensively used in fixed cell immunofluorescence and immunohistochemistry. Taking advantage of prostate and pancreatic cancer cell models known to have high basal Rac1-GTP levels, here we have established that this antibody does not recognize Rac1 but rather detects the intermediate filament protein vimentin. Indeed, Rac1-null PC3 prostate cancer cells or cancer models with low levels of Rac1 activation still show a high signal with the anti-Rac1-GTP antibody, which is lost upon silencing of vimentin expression. Moreover, this antibody was unable to detect activated Rac1 in membrane ruffles induced by epidermal growth factor stimulation. These results have profound implications for the study of this key GTPase in cancer, particularly because a large number of cancer cell lines with characteristic mesenchymal features show simultaneous up-regulation of vimentin and high basal Rac1-GTP levels when measured biochemically. This misleading correlation can lead to assumptions about the validity of this antibody and inaccurate conclusions that may affect the development of appropriate therapeutic approaches for targeting the Rac1 pathway.

Effects of Eicosapentaenoic Acid on Arterial Calcification

Arterial calcification is a hallmark of advanced atherosclerosis and predicts cardiovascular events. However, there is no clinically accepted therapy that prevents progression of arterial calcification. HMG-CoA reductase inhibitors, statins, lower low-density lipoprotein-cholesterol and reduce cardiovascular events, but coronary artery calcification is actually promoted by statins. The addition of eicosapentaenoic acid (EPA) to statins further reduced cardiovascular events in clinical trials, JELIS and REDUCE-IT. Additionally, we found that EPA significantly suppressed arterial calcification in vitro and in vivo via suppression of inflammatory responses, oxidative stress and Wnt signaling. However, so far there is a lack of evidence showing the effect of EPA on arterial calcification in a clinical situation. We reviewed the molecular mechanisms of the inhibitory effect of EPA on arterial calcification and the results of some clinical trials.

Role of Macrophages in the Progression and Regression of Vascular Calcification

Vascular calcification is an abnormal cell-mediated process in which bone-specific hydroxyapatite crystals are actively deposited on the blood vessel wall and is a significant pathological basis for the increased incidence and mortality of adverse cardiovascular events. Macrophages play an important regulatory role in the occurrence, development, and regression of vascular calcification. After the tissue microenvironment changes, macrophages subsequently change their polarity and phenotype or secrete functional substances as an adaptive response. As research on macrophages continue to move into this field, we gain a new understanding of the mechanism of the formation and regression of vascular calcification, which might offer valuable new intervention targets for the prevention and inhibition of vascular calcification. This review summarizes a wealth of research in this field and explores the roles of macrophages in the development process of vascular calcification.