Proprotein Convertase Subtilisin/Kexin 9 (PCSK9) Promotes Macrophage Activation via LDL Receptor-Independent Mechanisms.

BACKGROUND: Activated macrophages contribute to the pathogenesis of vascular disease. Vein graft failure is a major clinical problem with limited therapeutic options. PCSK9 (proprotein convertase subtilisin/kexin 9) increases low-density lipoprotein (LDL)-cholesterol levels via LDL receptor (LDLR) degradation. The role of PCSK9 in macrophage activation and vein graft failure is largely unknown, especially through LDLR-independent mechanisms. This study aimed to explore a novel mechanism of macrophage activation and vein graft disease induced by circulating PCSK9 in an LDLR-independent fashion. METHODS: We used Ldlr-/- mice to examine the LDLR-independent roles of circulating PCSK9 in experimental vein grafts. Adeno-associated virus (AAV) vector encoding a gain-of-function mutant of PCSK9 (rAAV8/D377Y-mPCSK9) induced hepatic PCSK9 overproduction. To explore novel inflammatory targets of PCSK9, we used systems biology in Ldlr-/- mouse macrophages. RESULTS: In Ldlr-/- mice, AAV-PCSK9 increased circulating PCSK9, but did not change serum cholesterol and triglyceride levels. AAV-PCSK9 promoted vein graft lesion development when compared with control AAV. In vivo molecular imaging revealed that AAV-PCSK9 increased macrophage accumulation and matrix metalloproteinase activity associated with decreased fibrillar collagen, a molecular determinant of atherosclerotic plaque stability. AAV-PCSK9 induced mRNA expression of the pro-inflammatory mediators IL-1ß (interleukin-1 beta), TNFα (tumor necrosis factor alpha), and MCP-1 (monocyte chemoattractant protein-1) in peritoneal macrophages underpinned by an in vitro analysis of Ldlr-/- mouse macrophages stimulated with endotoxin-free recombinant PCSK9. A combination of unbiased global transcriptomics and new network-based hyperedge entanglement prediction analysis identified the NF-κB (nuclear factor-kappa B) signaling molecules, lectin-like oxidized LOX-1 (LDL receptor-1), and SDC4 (syndecan-4) as potential PCSK9 targets mediating pro-inflammatory responses in macrophages. CONCLUSIONS: Circulating PCSK9 induces macrophage activation and vein graft lesion development via LDLR-independent mechanisms. PCSK9 may be a potential target for pharmacologic treatment for this unmet medical need.

Overview of the 87th Annual Scientific Meeting of the Japanese Circulation Society (JCS2023)　- New Challenge With Next Generation.

The 87thAnnual Meeting of the Japanese Circulation Society (JCS2023) was held in March 2023 in Fukuoka, Japan, marking the first in-person gathering after the COVID-19 pandemic. With the theme of "New Challenge With Next Generation" the conference emphasized the development of future cardiovascular leaders and technologies such as artificial intelligence (AI). Notable sessions included the Mikamo Lecture on heart failure and the Mashimo Lecture on AI in medicine. Various hands-on sessions and participatory events were well received, promoting learning and networking. Post-event surveys showed high satisfaction among participants, with positive feedback on face-to-face interactions and the overall experience. JCS2023, attended by 17,852 participants, concluded successfully, marking a significant milestone in post-pandemic meetings, and advancing cardiovascular medicine.

Macrophage (Drp1) Dynamin-Related Protein 1 Accelerates Intimal Thickening After Vascular Injury.

OBJECTIVE: Mitochondria consistently change their morphology in a process regulated by proteins, including Drp1 (dynamin-related protein 1), a protein promoting mitochondrial fission. Drp1 is involved in the mechanisms underlying various cardiovascular diseases, such as myocardial ischemia/reperfusion injury, heart failure, and pulmonary arterial hypertension. However, its role in macrophages, which promote various vascular diseases, is poorly understood. We therefore tested our hypothesis that macrophage Drp1 promotes vascular remodeling after injury. METHOD AND RESULTS: To explore the selective role of macrophage Drp1, we created macrophage-selective Drp1-deficient mice and performed femoral arterial wire injury. In these mice, intimal thickening and negative remodeling were attenuated at 4 weeks after injury when compared with control mice. Deletion of macrophage Drp1 also attenuated the macrophage accumulation and cell proliferation in the injured arteries. Gain- and loss-of-function experiments using cultured macrophages indicated that Drp1 induces the expression of molecules associated with inflammatory macrophages. Morphologically, mitochondrial fission was induced in inflammatory macrophages, whereas mitochondrial fusion was induced in less inflammatory/reparative macrophages. Pharmacological inhibition or knockdown of Drp1 decreased the mitochondrial reactive oxygen species and chemotactic activity in cultured macrophages. Co-culture experiments of macrophages with vascular smooth muscle cells indicated that deletion of macrophage Drp1 suppresses growth and migration of vascular smooth muscle cells induced by macrophage-derived soluble factors. CONCLUSIONS: Macrophage Drp1 accelerates intimal thickening after vascular injury by promoting macrophage-mediated inflammation. Macrophage Drp1 may be a potential therapeutic target of vascular diseases.

S100A9-RAGE Axis Accelerates Formation of Macrophage-Mediated Extracellular Vesicle Microcalcification in Diabetes Mellitus.

OBJECTIVE: Vascular calcification is a cardiovascular risk factor and accelerated in diabetes mellitus. Previous work has established a role for calcification-prone extracellular vesicles in promoting vascular calcification. However, the mechanisms by which diabetes mellitus provokes cardiovascular events remain incompletely understood. Our goal was to identify that increased S100A9 promotes the release of calcification-prone extracellular vesicles from human macrophages in diabetes mellitus. Approach and Results: Human primary macrophages exposed to high glucose (25 mmol/L) increased S100A9 secretion and the expression of receptor for advanced glycation end products (RAGE) protein. Recombinant S100A9 induced the expression of proinflammatory and osteogenic factors, as well as the number of extracellular vesicles with high calcific potential (alkaline phosphatase activity, P<0.001) in macrophages. Treatment with a RAGE antagonist or silencing with S100A9 siRNA in macrophages abolished these responses, suggesting that stimulation of the S100A9-RAGE axis by hyperglycemia favors a procalcific environment. We further showed that an imbalance between Nrf-2 (nuclear factor 2 erythroid related factor 2) and NF-κB (nuclear factor-κB) pathways contributes to macrophage activation and promotes a procalcific environment. In addition, streptozotocin-induced diabetic Apoe-/-S100a9-/- mice and mice treated with S100a9 siRNA encapsulated in macrophage-targeted lipid nanoparticles showed decreased inflammation and microcalcification in atherosclerotic plaques, as gauged by molecular imaging and comprehensive histological analysis. In human carotid plaques, comparative proteomics in patients with diabetes mellitus and histological analysis showed that the S100A9-RAGE axis associates with osteogenic activity and the formation of microcalcification. CONCLUSIONS: Under hyperglycemic conditions, macrophages release calcific extracellular vesicles through mechanisms involving the S100A9-RAGE axis, thus contributing to the formation of microcalcification within atherosclerotic plaques.

Uremic Toxin Indoxyl Sulfate Promotes Proinflammatory Macrophage Activation Via the Interplay of OATP2B1 and Dll4-Notch Signaling.

BACKGROUND: Chronic kidney disease (CKD) increases cardiovascular risk. Underlying mechanisms, however, remain obscure. The uremic toxin indoxyl sulfate is an independent cardiovascular risk factor in CKD. We explored the potential impact of indoxyl sulfate on proinflammatory activation of macrophages and its underlying mechanisms. METHODS: We examined in vitro the effects of clinically relevant concentrations of indoxyl sulfate on proinflammatory responses of macrophages and the roles of organic anion transporters and organic anion transporting polypeptides (OATPs). A systems approach, involving unbiased global proteomics, bioinformatics, and network analysis, then explored potential key pathways. To address the role of Delta-like 4 (Dll4) in indoxyl sulfate-induced macrophage activation and atherogenesis in CKD in vivo, we used 5/6 nephrectomy and Dll4 antibody in low-density lipoprotein receptor-deficient (Ldlr-/-) mice. To further determine the relative contribution of OATP2B1 or Dll4 to proinflammatory activation of macrophages and atherogenesis in vivo, we used siRNA delivered by macrophage-targeted lipid nanoparticles in mice. RESULTS: We found that indoxyl sulfate-induced proinflammatory macrophage activation is mediated by its uptake through transporters, including OATP2B1, encoded by the SLCO2B1 gene. The global proteomics identified potential mechanisms, including Notch signaling and the ubiquitin-proteasome pathway, that mediate indoxyl sulfate-triggered proinflammatory macrophage activation. We chose the Notch pathway as an example of key candidates for validation of our target discovery platform and for further mechanistic studies. As predicted computationally, indoxyl sulfate triggered Notch signaling, which was preceded by the rapid induction of Dll4 protein. Dll4 induction may result from inhibition of the ubiquitin-proteasome pathway, via the deubiquitinating enzyme USP5. In mice, macrophage-targeted OATP2B1/Slco2b1 silencing and Dll4 antibody inhibited proinflammatory activation of peritoneal macrophages induced by indoxyl sulfate. In low-density lipoprotein receptor-deficient mice, Dll4 antibody abolished atherosclerotic lesion development accelerated in Ldlr-/- mice. Moreover, coadministration of indoxyl sulfate and OATP2B1/Slco2b1 or Dll4 siRNA encapsulated in macrophage-targeted lipid nanoparticles in Ldlr-/- mice suppressed lesion development. CONCLUSIONS: These results suggest that novel crosstalk between OATP2B1 and Dll4-Notch signaling in macrophages mediates indoxyl sulfate-induced vascular inflammation in CKD.

Ezetimibe in Combination With Statins Ameliorates Endothelial Dysfunction in Coronary Arteries After Stenting: The CuVIC Trial (Effect of Cholesterol Absorption Inhibitor Usage on Target Vessel Dysfunction After Coronary Stenting), a Multicenter Randomized Controlled Trial.

OBJECTIVES: We sought to investigate whether treatment with ezetimibe in combination with statins improves coronary endothelial function in target vessels in coronary artery disease patients after coronary stenting. APPROACH AND RESULTS: We conducted a multicenter, prospective, randomized, open-label, blinded-end point trial among 11 cardiovascular treatment centers. From 2011 to 2013, 260 coronary artery disease patients who underwent coronary stenting were randomly allocated to 2 arms (statin monotherapy, S versus ezetimibe [10 mg/d]+statin combinational therapy, E+S). We defined target vessel dysfunction as the primary composite outcome, which comprised target vessel failure during treatment and at the 6- to 8-month follow-up coronary angiography and coronary endothelial dysfunction determined via intracoronary acetylcholine testing performed in cases without target vessel failure at the follow-up coronary angiography. Coadministration of ezetimibe with statins further lowered low-density lipoprotein cholesterol levels (83±23 mg/dL in S versus 67±23 mg/dL in E+S; P<0.0001), with significant decreases in oxidized low-density lipoprotein and oxysterol levels. Among patients without target vessel failure, 46 out of 89 patients (52%) in the S arm and 34 out of 96 patients (35%) in the E+S arm were found to have coronary endothelial dysfunction (P=0.0256), and the incidence of target vessel dysfunction at follow-up was significantly decreased in the E+S arm (69/112 (62%) in S versus 47/109 (43%) in E+S; P=0.0059). A post hoc analysis of post-treatment low-density lipoprotein cholesterol-matched subgroups revealed that the incidence of both target vessel dysfunction and coronary endothelial dysfunction significantly decreased in the E+S arm, with significant reductions in oxysterol levels. CONCLUSIONS: The CuVIC trial (Effect of Cholesterol Absorption Inhibitor Usage on Target Vessel Dysfunction after Coronary Stenting) has shown that ezetimibe with statins, compared with statin monotherapy, improves functional prognoses, ameliorating endothelial dysfunction in stented coronary arteries, and was associated with larger decreases in oxysterol levels.

Fatal Cardiac Hemochromatosis in a Patient with Hereditary Spherocytosis.

A 31-year-old man was admitted to our hospital with atrial tachycardia and cardiogenic shock. He had been diagnosed with hereditary spherocytosis (HS) during childhood, but he never received any red blood cell transfusions. Right ventricular endomyocardial biopsy revealed multiple myocardial hemosiderin deposits, and he was diagnosed with cardiac hemochromatosis. In addition to the iron deposition in the heart, the loss of myocyte and severe interstitial fibrosis were present. His cardiac function did not improve even after the cardioversion for atrial tachycardia, and he suffered from recurrent heart failure. Despite intensive medical treatment for heart failure and arrhythmias in combination with iron chelation therapy, he eventually died of progressive and refractory heart failure. Hemochromatosis is a systemic disorder characterized by the excessive deposition of iron in multiple organs. The occurrence of hemochromatosis in HS is extremely rare, and previous reports have shown that the coexistence of heterozygosity for the HFE gene mutation in HS patients causes excess iron storage. The prognosis is poor due to progressive congestive heart failure and refractory arrhythmias. Here we report a rare case of fatal cardiac hemochromatosis associated with HS. The possibility of cardiac hemochromatosis needs to be considered in cases of heart failure or arrhythmia in patients with HS.

Pioglitazone-Incorporated Nanoparticles Prevent Plaque Destabilization and Rupture by Regulating Monocyte/Macrophage Differentiation in ApoE-/- Mice.

OBJECTIVE: Inflammatory monocytes/macrophages produce various proteinases, including matrix metalloproteinases, and degradation of the extracellular matrix by these activated proteinases weakens the mechanical strength of atherosclerotic plaques, which results in a rupture of the plaque. Peroxisome proliferator-activated receptor-γ induces a polarity shift of monocytes/macrophages toward less inflammatory phenotypes and has the potential to prevent atherosclerotic plaque ruptures. Therefore, we hypothesized that nanoparticle-mediated targeted delivery of the peroxisome proliferator-activated receptor-γ agonist pioglitazone into circulating monocytes could effectively inhibit plaque ruptures in a mouse model. APPROACH AND RESULTS: We prepared bioabsorbable poly(lactic-co-glycolic-acid) nanoparticles containing pioglitazone (pioglitazone-NPs). Intravenously administered poly(lactic-co-glycolic-acid) nanoparticles incorporated with fluorescein isothiocyanate were found in circulating monocytes and aortic macrophages by flow cytometric analysis. Weekly intravenous administration of pioglitazone-NPs (7 mg/kg per week) for 4 weeks decreased buried fibrous caps, a surrogate marker of plaque rupture, in the brachiocephalic arteries of ApoE(-/-) mice fed a high-fat diet and infused with angiotensin II. In contrast, administration of control-NPs or an equivalent dose of oral pioglitazone treatment produced no effects. Pioglitazone-NPs inhibited the activity of matrix metalloproteinases and cathepsins in the brachiocephalic arteries. Pioglitazone-NPs regulated inflammatory cytokine expression and also suppressed the expression of extracellular matrix metalloproteinase inducer in bone marrow-derived macrophages. CONCLUSIONS: Nanoparticle-mediated delivery of pioglitazone inhibited macrophage activation and atherosclerotic plaque ruptures in hyperlipidemic ApoE(-/-) mice. These results demonstrate a promising strategy with a favorable safety profile to prevent atherosclerotic plaque ruptures.

Nanoparticle-mediated delivery of pitavastatin inhibits atherosclerotic plaque destabilization/rupture in mice by regulating the recruitment of inflammatory monocytes.

BACKGROUND: Preventing atherosclerotic plaque destabilization and rupture is the most reasonable therapeutic strategy for acute myocardial infarction. Therefore, we tested the hypotheses that (1) inflammatory monocytes play a causative role in plaque destabilization and rupture and (2) the nanoparticle-mediated delivery of pitavastatin into circulating inflammatory monocytes inhibits plaque destabilization and rupture. METHODS AND RESULTS: We used a model of plaque destabilization and rupture in the brachiocephalic arteries of apolipoprotein E-deficient (ApoE(-/-)) mice fed a high-fat diet and infused with angiotensin II. The adoptive transfer of CCR2(+/+)Ly-6C(high) inflammatory macrophages, but not CCR2(-/-) leukocytes, accelerated plaque destabilization associated with increased serum monocyte chemoattractant protein-1 (MCP-1), monocyte-colony stimulating factor, and matrix metalloproteinase-9. We prepared poly(lactic-co-glycolic) acid nanoparticles that were incorporated by Ly-6G(-)CD11b(+) monocytes and delivered into atherosclerotic plaques after intravenous administration. Intravenous treatment with pitavastatin-incorporated nanoparticles, but not with control nanoparticles or pitavastatin alone, inhibited plaque destabilization and rupture associated with decreased monocyte infiltration and gelatinase activity in the plaque. Pitavastatin-incorporated nanoparticles inhibited MCP-1-induced monocyte chemotaxis and the secretion of MCP-1 and matrix metalloproteinase-9 from cultured macrophages. Furthermore, the nanoparticle-mediated anti-MCP-1 gene therapy reduced the incidence of plaque destabilization and rupture. CONCLUSIONS: The recruitment of inflammatory monocytes is critical in the pathogenesis of plaque destabilization and rupture, and nanoparticle-mediated pitavastatin delivery is a promising therapeutic strategy to inhibit plaque destabilization and rupture by regulating MCP-1/CCR2-dependent monocyte recruitment in this model.

EVs-miR-17-5p attenuates the osteogenic differentiation of vascular smooth muscle cells potentially via inhibition of TGF-ß signaling under high glucose conditions.

Vascular calcification, which is a major complication of diabetes mellitus, is an independent risk factor for cardiovascular disease. Osteogenic differentiation of vascular smooth muscle cells (VSMCs) is one of the key mechanisms underlying vascular calcification. Emerging evidence suggests that macrophage-derived extracellular vesicles (EVs) may be involved in calcification within atherosclerotic plaques in patients with diabetes mellitus. However, the role of macrophage-derived EVs in the progression of vascular calcification is largely unknown. In this study, we investigated whether macrophage-derived EVs contribute to the osteogenic differentiation of VSMCs under high glucose conditions. We isolated EVs that were secreted by murine peritoneal macrophages under normal glucose (EVs-NG) or high glucose (EVs-HG) conditions. miRNA array analysis in EVs from murine macrophages showed that miR-17-5p was significantly increased in EVs-HG compared with EVs-NG. Prediction analysis with miRbase identified transforming growth factor ß receptor type II (TGF-ß RII) as a potential target of miR-17-5p. EVs-HG as well as miR-17-5p overexpression with lipid nanoparticles inhibited the gene expression of Runx2, and TGF-ß RII. Furthermore, we demonstrated that VSMCs transfected with miR-17-5p mimic inhibited calcium deposition. Our findings reveal a novel role of macrophage-derived EVs in the negative regulation of osteogenic differentiation in VSMCs under high glucose conditions.

Cyclophilin D induces necrotic core formation by mediating mitochondria-associated macrophage death in advanced atherosclerotic lesions.

BACKGROUND AND AIMS: In advanced atherosclerotic lesions, macrophage deaths result in necrotic core formation and plaque vulnerability. Cyclophilin D (CypD) is a mitochondria-specific cyclophilin involved in the process of cell death after organ ischemia-reperfusion. However, the role of CypD in atherosclerosis, especially in necrotic core formation, is unknown. Therefore, this experiment aims to clarify the role of CypD in necrotic core formation. METHODS: To clarify the specific role of CypD, encoded by Ppif in mice, apolipoprotein-E/CypD-double knockout (Apoe-/-Ppif-/-) mice were generated. These mice were fed a high-fat diet containing 0.15 % cholesterol for 24 weeks to accelerate atherosclerotic lesion development. RESULTS: Deletion of CypD decreased the necrotic core size, accompanied by a reduction of macrophage apoptosis compared to control Apoe-/- mice. In RAW264.7 cells, siRNA-mediated knockdown of CypD attenuated the release of cytochrome c from the mitochondria to the cytosol induced by endoplasmic reticulum stress inducer thapsigargin. In addition, necroptosis, induced by TNF-α and caspase inhibitor, was attenuated by knockdown of CypD. Ly-6Chigh inflammatory monocytes in peripheral blood leukocytes and mRNA expression of Il1b in the aorta were decreased by deletion of CypD. In contrast, siRNA-mediated knockdown of CypD did not significantly decrease Il1b nor Ccl2 mRNA expression in RAW264.7 cells treated with LPS and IFN-γ, suggesting that inhibition of inflammation in vivo is likely due to decreased cell death in the atherosclerotic lesions rather than a direct action of CypD deletion on the macrophage. CONCLUSIONS: These results indicate that CypD induces macrophage death and mediates necrotic core formation in advanced atherosclerotic lesions. CypD could be a novel therapeutic target for treating atherosclerotic vascular diseases.

Impact of the Coronavirus Disease 2019 (COVID-19) Pandemic on the Severity and the Mortality of Acute Myocardial Infarction in Japan　- Analysis From the JROAD-DPC Database.

Background: Coronavirus disease 2019 (COVID-19) has impacted on cardiovascular disease. However, it remains unclear whether the COVID-19 pandemic has impacted on disease severity and patients' prognosis of acute myocardial infarction (AMI) in Japan. Methods and Results: We retrospectively accumulated data from the Japanese Registry of All Cardiac and Vascular Diseases-Diagnosis Procedure Combination (JROAD-DPC) study (April 2019 to March 2021). Patients were divided into a before COVID-19 pandemic group or a during COVID-19 pandemic group. The proportion of patients who presented with cardiogenic shock (Killip class IV) was compared between groups, in association with 30-day mortality as the primary outcome. Killip class IV AMI significantly increased in the during COVID-19 pandemic group (15.7% vs. 14.5% in the before pandemic group, P<0.0001). The 30-day mortality was higher in the during COVID-19 pandemic group (9.6% vs. 9.2% in the before COVID-19 pandemic group, P=0.049). However, there was no significant difference in the adjusted 30-day mortality in each Killip class between the before and during COVID-19 pandemic groups. Conclusions: During the early stage of the COVID-19 pandemic in Japan, 30-day mortality of AMI increased, mainly because of the increase of Killip class IV AMI patients. However, irrespective of the COVID-19 pandemic, the adjusted 30-day mortality of each Killip classification group was unchanged.

Temporal Trends in Antithrombotic Therapy for Patients With Atrial Fibrillation Undergoing Percutaneous Coronary Intervention From 2014 to 2022 in Japan.

Background: Recent revisions of clinical guidelines by the Japanese Circulation Society, American Heart Association/American College of Cardiology, and European Society of Cardiology updated the management of antithrombotic strategies for patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI). However, the extent to which these guidelines have been implemented in real-world daily clinical practice is unclear. Methods and Results: We conducted surveys on the status of antithrombotic therapy for patients with AF undergoing PCI every 2 years from 2014 to 2022 in 14 cardiovascular centers in Japan. The primary use of drug-eluting stents increased from 10% in 2014 to 95-100% in 2018, and the use of direct oral anticoagulants increased from 15% in 2014 to 100% in 2018, in accordance with the revised practice guidelines. In patients with acute coronary syndrome, the duration of triple therapy within 1 month was approximately 10% until 2018, and increased to >70% from 2020. In patients with chronic coronary syndrome, the duration of triple therapy within 1 month was approximately 10% until 2016, and >75% from 2018. Since 2020, the most common timing of discontinuation of dual antiplatelet therapy to transition to anticoagulation monotherapy during the chronic phase of PCI has been 1 year after PCI. Conclusions: Japanese interventional cardiologists have updated their treatment strategies for patients with AF undergoing PCI according to revisions of clinical practice guidelines.

Association of Serum Oxysterols with Cholesterol Metabolism Markers and Clinical Factors in Patients with Coronary Artery Disease: A Covariance Structure Analysis.

Oxysterols have been implicated in the pathogenesis of cardiovascular diseases. Serum levels of oxysterols could be positively correlated with cholesterol absorption and synthesis. However, physiological regulation of various serum oxysterols is largely unknown. The aim of this study was to investigate the relationship between clinical factors and cholesterol metabolism markers, and identify oxysterols associated with cholesterol absorption and synthesis in patients with coronary artery disease. Subjects (n = 207) who underwent coronary stenting between 2011 and 2013 were studied cross-sectionally. We measured lipid profiles including serum oxysterols. As for the serum biomarkers of cholesterol synthesis and absorption, oxysterol levels were positively correlated with campesterol and lathosterol. Covariance structure analysis revealed that dyslipidemia and statin usage had a positive correlation with "cholesterol absorption". Statin usage also had a positive correlation with "cholesterol synthesis". Several oxysterols associated with cholesterol absorption and/or synthesis. In conclusion, we elucidated the potential clinical factors that may affect cholesterol metabolism, and the associations between various oxysterols with cholesterol absorption and/or synthesis in patients with coronary artery disease.

Association between Serum Oxysterols and Coronary Plaque Regression during Lipid-Lowering Therapy with Statin and Ezetimibe: Insights from the CuVIC Trial.

AIM: Several clinical trials using intravascular ultrasound (IVUS) evaluation have demonstrated that intensive lipid-lowering therapy by statin or a combination therapy with statin and ezetimibe results in significant regression of coronary plaque volume. However, it remains unclear whether adding ezetimibe to statin therapy affects coronary plaque composition and the molecular mechanisms of plaque regression. We conducted this prospective IVUS analysis in a subgroup from the CuVIC trial. METHODS: The CuVIC trial was a prospective randomized, open, blinded-endpoint trial conducted among 11 cardiovascular centers, where 260 patients with coronary artery disease who received coronary stenting were randomly allocated into either the statin group (S) or the combined statin and ezetimibe group (S＋E). We enrolled 79 patients (S group, 39 patients; S＋E group, 40 patients) in this substudy, for whom serial IVUS images of nonculprit lesion were available at both baseline and after 6-8 months of follow-up. RESULTS: After the treatment period, the S＋E group had significantly lower level of low-density lipoprotein cholesterol (LDL-C; 80.9±3.7 vs. 67.7±3.8 mg/dL, p=0.0143). Campesterol, a marker of cholesterol absorption, and oxysterols (ß-epoxycholesterol, 4ß-hydroxycholesterol, and 27-hydroxycholesterol) were also lower in the S＋E group. IVUS analyses revealed greater plaque regression in the S＋E group than in the S group (-6.14% vs. -1.18% for each group, p=0.042). It was noteworthy that the lowering of campesterol and 27-hydroxycholesterol, but not LDL-C, had a significant positive correlation with plaque regression. CONCLUSIONS: Compared with statin monotherapy, ezetimibe in combination with statin achieved significantly lower LDL-C, campesterol, and 27-hydroxycholesterol, which resulted in greater coronary plaque regression.

Association of Serum Levels of Cholesterol Absorption and Synthesis Markers with the Presence of Cardiovascular Disease: The CACHE Study CVD Analysis.

AIM: Serum levels of cholesterol absorption and synthesis markers have been associated with cardiovascular risk in the United States and European countries. In this study, we examined the relevance of these biomarkers and the presence of cardiovascular disease (CVD) in Japanese individuals. METHODS: The CACHE consortium, comprising of 13 research groups in Japan possessing data on campesterol, an absorption marker, and lathosterol, a synthesis marker measured by gas chromatography, compiled the clinical data using the REDCap system. RESULTS: Among the 2,944 individuals in the CACHE population, those with missing campesterol or lathosterol data were excluded. This cross-sectional study was able to analyze data from 2,895 individuals, including 339 coronary artery disease (CAD) patients, 108 cerebrovascular disease (CeVD) patients, and 88 peripheral artery disease (PAD) patients. The median age was 57 years, 43% were female, and the median low-density lipoprotein cholesterol and triglyceride levels were 118 mg/dL and 98 mg/dL, respectively. We assessed the associations of campesterol, lathosterol, and the ratio of campesterol to lathosterol (Campe/Latho ratio) with the odds of CVD using multivariable-adjusted nonlinear regression models. The prevalence of CVD, especially CAD, showed positive, inverse, and positive associations with campesterol, lathosterol, and the Campe/Latho ratio, respectively. These associations remained significant even after excluding individuals using statins and/or ezetimibe. The associations of the cholesterol biomarkers with PAD were determined weaker than those with CAD. Contrarily, no significant association was noted between cholesterol metabolism biomarkers and CeVD. CONCLUSION: This study showed that both high cholesterol absorption and low cholesterol synthesis biomarker levels were associated with high odds of CVD, especially CAD.

Comparison of Endothelial Dysfunction in Coronary Arteries with Bare Metal and 2nd-Generation Drug-Eluting Stents.

AIMS: Previous studies suggested that implantation with a 1st-generation DES was associated with coronary endothelial dysfunction, which was associated with Rho-kinase activation. Second-generation drug-eluting stents (DESs) may preserve coronary endothelial function in stented coronary arteries; however, because of methodological limitations, further study is needed to clarify the association between 2 nd-generation DESs and coronary endothelial dysfunction. METHODS: We retrospectively analysed the CuVIC trial database, where we identified 112 patients who underwent coronary stenting in the left coronary arteries with either a bare metal stent (BMS, n=53) or 2nd-generation DES (n=59). We compared vasomotions of target vessels with stents and non-target vessels without stents. Furthermore, we measured the Rho-kinase activation detected in mononucleocytes from aortic and coronary sinus blood. RESULTS: ACh-induced vasoconstrictive responses of target vessels were not enhanced with a 2nd-generation DES (45±21% vs. 44±20%, P=0.56, paired t-test), but significantly enhanced in the coronary arteries with a BMS (50±18% vs. 42±20%, P=0.002). Rho-kinase activation did not differ between patients with a BMS and 2nd-generation DES. In the target vessels with a BMS, large late lumen loss and acute coronary syndrome (ACS) at the index percutaneous coronary intervention (PCI) were associated with ACh-induced enhanced coronary vasoconstrictive responses. CONCLUSIONS: Evaluation of ACh-induced vasomotion of target vessels comparing with non-target vessels revealed that 2nd-generation DESs were not associated with coronary endothelial dysfunction in target vessels, nor activation of Rho-kinase in the coronary sinus blood 6-8 months after stenting.

Nanoparticle-Mediated Delivery of Pitavastatin to Monocytes/Macrophages Inhibits Angiotensin II-Induced Abdominal Aortic Aneurysm Formation in Apoe-/- Mice.

AIM: Abdominal aortic aneurysm (AAA) is a lethal and multifactorial disease. To prevent a rupture and dissection of enlarged AAA, prophylactic surgery and stenting are currently available. There are, however, no medical therapies preventing these complications of AAA. Statin is one of the candidates, but its efficacy on AAA formation/progression remains controversial. We have previously demonstrated that nanoparticles (NPs) incorporating pitavastatin (Pitava-NPs)-clinical trials using these nanoparticles have been already conducted-suppressed progression of atherosclerosis in apolipoprotein E-deficient ( Apoe-/-) mice. Therefore, we have tested a hypothesis that monocytes/macrophages-targeting delivery of pitavastatin prevents the progression of AAA. METHODS: Angiotensin II was intraperitoneally injected by osmotic mini-pumps to induce AAA formation in Apoe-/- mice. NPs consisting of poly(lactic-co-glycolic acid) were used for in vivo delivery of pitavastatin to monocytes/macrophages. RESULTS: Intravenously administered Pitava-NPs (containing 0.012 mg/kg/week pitavastatin) inhibited AAA formation accompanied with reduction of macrophage accumulation and monocyte chemoattractant protein-1 (MCP-1) expression. Ex vivo molecular imaging revealed that Pitava-NPs not only reduced macrophage accumulation but also attenuated matrix metalloproteinase activity in the abdominal aorta, which was underpinned by attenuated elastin degradation. CONCLUSION: These results suggest that Pitava-NPs inhibit AAA formation associated with reduced macrophage accumulation and MCP-1 expression. This clinically feasible nanomedicine could be an innovative therapeutic strategy that prevents devastating complications of AAA.

Dietary 7-ketocholesterol exacerbates myocardial ischemia-reperfusion injury in mice through monocyte/macrophage-mediated inflammation.

Emerging evidence suggests that 7-ketocholesterol (7-KC), one of the most abundant dietary oxysterols, causes inflammation and cardiovascular diseases. Here we show the deteriorating effects of dietary 7-KC on myocardial ischemia-reperfusion (IR) injury and detailed the molecular mechanisms. A high-fat high-cholesterol diet containing 7-KC (7KWD) for 3 weeks increased the plasma 7-KC level compared with high-fat high-cholesterol diet in mice. In wild-type mice but not in CCR2-/- mice, dietary 7-KC increased the myocardial infarct size after IR. Flow cytometry revealed that the ratio of Ly-6Chigh inflammatory monocytes to total monocytes was increased in the 7KWD group. Unbiased RNA sequencing using murine primary macrophages revealed that 7-KC regulated the expression of transcripts related to inflammation and cholesterol biosynthesis. We further validated that in vitro, 7-KC induced endoplasmic reticulum stress, mitochondrial reactive oxygen species production, and nuclear factor-kappa B activation, which are associated with increased mRNA levels of proinflammatory cytokines. Administration of N-acetyl-L-cysteine or siRNA-mediated knockdown of PKR-like endoplasmic reticulum kinase or endoplasmic reticulum oxidase 1α suppressed the levels of 7-KC-induced inflammation. Dietary 7-KC exacerbates myocardial IR injury through monocyte/macrophage-mediated inflammation. Endoplasmic reticulum stress and oxidative stress are involved in the 7-KC-induced proinflammatory response in macrophages.

Patient hiPSCs Identify Vascular Smooth Muscle Arylacetamide Deacetylase as Protective against Atherosclerosis.

Although susceptibility to cardiovascular disease (CVD) is different for every patient, why some patients with type 2 diabetes mellitus (T2DM) develop CVD while others are protected has not yet been clarified. Using T2DM-patient-derived human induced pluripotent stem cells (hiPSCs), we found that in patients protected from CVD, there was significantly elevated expression of an esterase, arylacetamide deacetylase (AADAC), in vascular smooth muscle cells (VSMCs). We overexpressed this esterase in human primary VSMCs and VSMCs differentiated from hiPSCs and observed that the number of lipid droplets was significantly diminished. Further metabolomic analyses revealed a marked reduction in storage lipids and an increase in membrane phospholipids, suggesting changes in the Kennedy pathway of lipid bioassembly. Cell migration and proliferation were also significantly decreased in AADAC-overexpressing VSMCs. Moreover, apolipoprotein E (Apoe)-knockout mice overexpressing VSMC-specific Aadac showed amelioration of atherosclerotic lesions. Our findings suggest that higher AADAC expression in VSMCs protects T2DM patients from CVD.