RESUMO
Statins are widely used for the treatment of atherosclerotic cardiovascular diseases. They inhibit cholesterol biosynthesis in the liver and cause pleiotropic effects, including anti-inflammatory and antioxidant effects. To develop novel therapeutic drugs, the effect of blood-borne lipid molecules on the pleiotropic effects of statins must be elucidated. Myocardial infarction-prone Watanabe heritable hyperlipidemic (WHHLMI) rabbits, an animal model for hypercholesterolemia, are suitable for the determination of lipid molecules in the blood in response to statins because their lipoprotein metabolism is similar to that of humans. Herein, lipid molecules were investigated by lipidome analysis in response to pitavastatin using WHHLMI rabbits. Various lipid molecules in the blood were measured using a supercritical fluid chromatography triple quadrupole mass spectrometry. Cholesterol and cholesterol ester blood concentrations decreased by reducing the secretion of very low density lipoproteins from the liver. Independent of the inhibition effects of cholesterol biosynthesis, the concentrations of some lipids with anti-inflammation and antioxidant effects (phospholipid molecules with n-6 fatty acid side chains, lysophosphatidylcholines, phosphatidylethanolamine plasmalogens, and ceramide molecules) were significantly altered. These findings may lead to further investigation of the mechanism of statin action.
Assuntos
Inibidores de Hidroximetilglutaril-CoA Redutases , Hiperlipoproteinemia Tipo II , Quinolinas , Animais , Modelos Animais de Doenças , Hiperlipoproteinemia Tipo II/tratamento farmacológico , Hiperlipoproteinemia Tipo II/genética , Lipoproteínas , Quinolinas/farmacologia , CoelhosRESUMO
Matrix metalloproteinase-9 (MMP-9), or gelatinase B, has been hypothesized to be involved in the progression of atherosclerosis. In the arterial wall, accumulated macrophages secrete considerable amounts of MMP-9 but its pathophysiological functions in atherosclerosis have not been fully elucidated. To examine the hypothesis that macrophage-derived MMP-9 may affect atherosclerosis, we created MMP-9 transgenic (Tg) rabbits to overexpress the rabbit MMP-9 gene under the control of the scavenger receptor A enhancer/promoter and examined their susceptibility to cholesterol diet-induced atherosclerosis. Tg rabbits along with non-Tg rabbits were fed a cholesterol diet for 16 and 28 weeks, and their aortic and coronary atherosclerosis was compared. Gross aortic lesion areas were significantly increased in female Tg rabbits at 28 weeks; however, pathological examination revealed that all the lesions of Tg rabbits fed a cholesterol diet for either 16 or 28 weeks were characterized by increased monocyte/macrophage accumulation and prominent lipid core formation compared with those of non-Tg rabbits. Macrophages isolated from Tg rabbits exhibited higher infiltrative activity towards a chemoattractant, MCP-1 in vitro and augmented capability of hydrolysing extracellular matrix in granulomatous tissue. Surprisingly, the lesions of Tg rabbits showed more advanced lesions with remarkable calcification in both aortas and coronary arteries. In conclusion, macrophage-derived MMP-9 facilitates the infiltration of monocyte/macrophages into the lesions thereby enhancing the progression of atherosclerosis. Increased accumulation of lesional macrophages may promote vascular calcification.
Assuntos
Doença da Artéria Coronariana/genética , Metaloproteinase 9 da Matriz/genética , Calcificação Vascular/genética , Animais , Animais Geneticamente Modificados/genética , Aorta/efeitos dos fármacos , Aorta/crescimento & desenvolvimento , Aorta/patologia , Colesterol na Dieta/efeitos adversos , Doença da Artéria Coronariana/patologia , Vasos Coronários/efeitos dos fármacos , Vasos Coronários/metabolismo , Vasos Coronários/patologia , Modelos Animais de Doenças , Progressão da Doença , Humanos , Macrófagos/metabolismo , Macrófagos/patologia , Coelhos , Calcificação Vascular/patologiaRESUMO
Lipidomics, the mass spectrometry-based comprehensive analysis of lipids, has attracted attention as an analytical approach to provide novel insight into lipid metabolism and to search for biomarkers. However, an ideal method for both comprehensive and quantitative analysis of lipids has not been fully developed. Here, we have proposed a practical methodology for widely targeted quantitative lipidome analysis using supercritical fluid chromatography fast-scanning triple-quadrupole mass spectrometry (SFC/QqQMS) and theoretically calculated a comprehensive lipid multiple reaction monitoring (MRM) library. Lipid classes can be separated by SFC with a normal-phase diethylamine-bonded silica column with high resolution, high throughput, and good repeatability. Structural isomers of phospholipids can be monitored by mass spectrometric separation with fatty acyl-based MRM transitions. SFC/QqQMS analysis with an internal standard-dilution method offers quantitative information for both lipid class and individual lipid molecular species in the same lipid class. Additionally, data acquired using this method has advantages, including reduction of misidentification and acceleration of data analysis. Using the SFC/QqQMS system, alteration of plasma lipid levels in myocardial infarction-prone rabbits to the supplementation of EPA was first observed. Our developed SFC/QqQMS method represents a potentially useful tool for in-depth studies focused on complex lipid metabolism and biomarker discovery.-Takeda, H., Y. Izumi, M. Takahashi, T. Paxton, S. Tamura, T. Koike, Y. Yu, N. Kato, K. Nagase, M. Shiomi, and T. Bamba.
Assuntos
Cromatografia com Fluido Supercrítico , Metabolismo dos Lipídeos , Espectrometria de Massas , Metabolômica/métodos , Animais , Isomerismo , Lipídeos/sangue , Lipídeos/química , Lipídeos/isolamento & purificação , Infarto do Miocárdio/metabolismo , Coelhos , Reprodutibilidade dos Testes , Fatores de TempoRESUMO
OBJECTIVE: This study tested the hypothesis that vasospasm can trigger coronary plaque injury and acute ischemic myocardial damage. APPROACH AND RESULTS: Myocardial infarction-prone strain of the Watanabe heritable hyperlipidemic rabbits received an intravenous bolus of ergonovine maleate (0.45 µmol/kg) during intravenous infusion of norepinephrine (12 nmol/kg per minute) to provoke coronary spasm in vivo. After this treatment, coronary angiography demonstrated vasospasm, and the ECG showed ischemic abnormalities (ST depression/elevation and T-wave inversion) in 77% of animals (23/30). These changes normalized after nitroglycerin injection. In rabbits that demonstrated these ECG findings for >20 minutes, echocardiograms showed left ventricular wall motion abnormality. Serum levels of heart-type fatty acid-binding protein, cardiac troponin-I, and myoglobin increased markedly 4 hours after spasm provocation. In coronary lesions of myocardial infarction-prone strain of the Watanabe heritable hyperlipidemic rabbits with provoked coronary spasm, we observed intimal injury in 60.9% in the form of endothelial cell protrusions (39.1%), denudation (30.4%), and macrophage extravasation (56.5%). Plaque disruption with luminal thrombus, however, was only seen in 2 of 23 animals (8.7%), and mural microthrombus was rarely observed (4.3%). CONCLUSIONS: These observations show that provocation of vasospasm in myocardial infarction-prone strain of the Watanabe heritable hyperlipidemic rabbits associates with subsequent ischemic myocardial damage. Although treatment with spasmogens altered aspects of plaque morphology, for example, endothelial protrusion and macrophage emigration, thrombosis was rare in these animals with chronic atherosclerotic disease.
Assuntos
Doença da Artéria Coronariana/fisiopatologia , Vasoespasmo Coronário/fisiopatologia , Hiperlipidemias/fisiopatologia , Infarto do Miocárdio/fisiopatologia , Isquemia Miocárdica/fisiopatologia , Síndrome Coronariana Aguda/induzido quimicamente , Síndrome Coronariana Aguda/genética , Síndrome Coronariana Aguda/fisiopatologia , Animais , Doença da Artéria Coronariana/genética , Vasoespasmo Coronário/induzido quimicamente , Vasoespasmo Coronário/genética , Vasos Coronários/efeitos dos fármacos , Vasos Coronários/patologia , Modelos Animais de Doenças , Ergonovina/farmacologia , Hiperlipidemias/genética , Infarto do Miocárdio/genética , Isquemia Miocárdica/induzido quimicamente , Isquemia Miocárdica/genética , Norepinefrina/farmacologia , Ocitócicos/farmacologia , Coelhos , Vasoconstrição/efeitos dos fármacos , Vasoconstrição/fisiologia , Vasoconstritores/farmacologiaRESUMO
OBJECTIVE: Apolipoprotein (apo) A-II is the second major apo of high-density lipoproteins, yet its pathophysiological roles in the development of atherosclerosis remain unknown. We aimed to examine whether apo A-II plays any role in atherogenesis and, if so, to elucidate the mechanism involved. METHODS AND RESULTS: We compared the susceptibility of human apo A-II transgenic (Tg) rabbits to cholesterol diet-induced atherosclerosis with non-Tg littermate rabbits. Tg rabbits developed significantly less aortic and coronary atherosclerosis than their non-Tg littermates, while total plasma cholesterol levels were similar. Atherosclerotic lesions of Tg rabbits were characterized by reduced macrophages and smooth muscle cells, and apo A-II immunoreactive proteins were frequently detected in the lesions. Tg rabbits exhibited low levels of plasma C-reactive protein and blood leukocytes compared with non-Tg rabbits, and high-density lipoproteins of Tg rabbit plasma exerted stronger cholesterol efflux activity and inhibitory effects on the inflammatory cytokine expression by macrophages in vitro than high-density lipoproteins isolated from non-Tg rabbits. In addition, ß-very-low-density lipoproteins of Tg rabbits were less sensitive to copper-induced oxidation than ß-very-low-density lipoproteins of non-Tg rabbits. CONCLUSIONS: These results suggest that enrichment of apo A-II in high-density lipoprotein particles has atheroprotective effects and apo A-II may become a target for the treatment of atherosclerosis.
Assuntos
Aorta/metabolismo , Doenças da Aorta/prevenção & controle , Apolipoproteína A-II/metabolismo , Aterosclerose/prevenção & controle , Doença da Artéria Coronariana/prevenção & controle , Vasos Coronários/metabolismo , Animais , Animais Geneticamente Modificados , Aorta/imunologia , Aorta/patologia , Doenças da Aorta/sangue , Doenças da Aorta/etiologia , Doenças da Aorta/genética , Doenças da Aorta/imunologia , Doenças da Aorta/patologia , Apolipoproteína A-II/sangue , Apolipoproteína A-II/genética , Aterosclerose/sangue , Aterosclerose/etiologia , Aterosclerose/genética , Aterosclerose/imunologia , Aterosclerose/patologia , Colesterol na Dieta/sangue , Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/etiologia , Doença da Artéria Coronariana/genética , Doença da Artéria Coronariana/imunologia , Doença da Artéria Coronariana/patologia , Vasos Coronários/imunologia , Vasos Coronários/patologia , Citocinas/sangue , Modelos Animais de Doenças , Feminino , Humanos , Mediadores da Inflamação/sangue , Lipoproteínas HDL/sangue , Lipoproteínas LDL/sangue , Lipoproteínas VLDL/sangue , Masculino , Oxirredução , Placa Aterosclerótica , Coelhos , Fatores de TempoRESUMO
Lipoprotein, especially high-density lipoprotein (HDL), particles are composed of multiple heterogeneous subgroups containing various proteins and lipids. The molecular distribution among these subgroups is closely related to cardiovascular disease (CVD). Here, we established high-resolution proteomics and lipidomics (HiPL) methods to depict the molecular profiles across lipoprotein (Lipo-HiPL) and HDL (HDL-HiPL) subgroups by optimizing the resolution of anion-exchange chromatography and comprehensive quantification of proteins and lipids on the omics level. Furthermore, based on the Pearson correlation coefficient analysis of molecular profiles across high-resolution subgroups, we achieved the relationship of proteomeâlipidome connectivity (PLC) for lipoprotein and HDL particles. By application of these methods to high-fat, high-cholesterol diet-fed rabbits and acute coronary syndrome (ACS) patients, we uncovered the delicate dynamics of the molecular profile and reconstruction of lipoprotein and HDL particles. Of note, the PLC features revealed by the HDL-HiPL method discriminated ACS from healthy individuals better than direct proteome and lipidome quantification or PLC features revealed by the Lipo-HiPL method, suggesting their potential in ACS diagnosis. Together, we established HiPL methods to trace the dynamics of the molecular profile and PLC of lipoprotein and even HDL during the development of CVD.
Assuntos
Aterosclerose , Doenças Cardiovasculares , Animais , Doenças Cardiovasculares/metabolismo , Lipidômica , Lipoproteínas , Lipoproteínas HDL/metabolismo , Proteoma/metabolismo , CoelhosRESUMO
Loss-of-function mutations in the forkhead box N1 (FOXN1) gene lead to nude severe combined immunodeficiency, a rare inherited syndrome characterized by athymia, severe T cell immunodeficiency, congenital alopecia, and nail dystrophy. We recently produced FOXN1 mutant nude rabbits (NuRabbits) by using CRISPR-Cas9. Here we report the establishment and maintenance of the NuRabbit colony. NuRabbits, like nude mice, are hairless, lack thymic development, and are immunodeficient. To demonstrate the functional applications of NuRabbits in biomedical research, we show that they can successfully serve as the recipient animals in xenotransplantation experiments using human induced pluripotent stem cells or tissue-engineered blood vessels. Our work presents the NuRabbit as a new member of the immunodeficient animal model family. The relatively large size and long lifespan of NuRabbits offer unique applications in regenerative medicine, cancer research, and the study of a variety of other human conditions, including immunodeficiency.
Assuntos
Fatores de Transcrição Forkhead/fisiologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Modelos Animais , Linfócitos T/metabolismo , Teratoma/metabolismo , Animais , Animais Geneticamente Modificados/fisiologia , Prótese Vascular , Humanos , Camundongos , Camundongos Nus , Mutação , Coelhos , Imunodeficiência Combinada Severa/genética , Transplante HeterólogoRESUMO
BACKGROUND AND AIMS: Apolipoprotein A-II (apoAII) is the second major apolipoprotein of the high-density lipoprotein (HDL) particle, after apoAI. Unlike apoAI, the biological and physiological functions of apoAII are unclear. We aimed to gain insight into the specific roles of apoAII in lipoprotein metabolism and atherosclerosis using a novel rabbit model. METHODS: Wild-type (WT) rabbits are naturally deficient in apoAII, thus their HDL contains only apoAI. Using TALEN technology, we replaced the endogenous apoAI in rabbits through knock-in (KI) of human apoAII. The newly generated apoAII KI rabbits were used to study the specific function of apoAII, independent of apoAI. RESULTS: ApoAII KI rabbits expressed exclusively apoAII without apoAI, as confirmed by RT-PCR and Western blotting. On a standard diet, the KI rabbits exhibited lower plasma triglycerides (TG, 52%, p < 0.01) due to accelerated clearance of TG-rich particles and higher lipoprotein lipase activity than the WT littermates. ApoAII KI rabbits also had higher plasma HDL-C (28%, p < 0.05) and their HDL was rich in apoE, apoAIV, and apoAV. When fed a cholesterol-rich diet for 16 weeks, apoAII KI rabbits were resistant to diet-induced hypertriglyceridemia and developed significantly less aortic atherosclerosis compared to WT rabbits. HDL isolated from rabbits with apoAII KI had similar cholesterol efflux capacity and anti-inflammatory effects as HDL isolated from the WT rabbits. CONCLUSIONS: ApoAII KI rabbits developed less atherosclerosis than WT rabbits, possibly through increased plasma HDL-C, reduced TG and atherogenic lipoproteins. These results suggest that apoAII may serve as a potential target for the treatment of atherosclerosis.
Assuntos
Apolipoproteína A-II , Aterosclerose , Animais , Apolipoproteína A-I/genética , Aterosclerose/genética , Aterosclerose/prevenção & controle , Colesterol , Humanos , Lipoproteínas HDL , CoelhosRESUMO
BACKGROUND: Although there is a statistically significant association between modestly raised baseline plasma C-reactive protein (CRP) values and future cardiovascular events, the debate is still unsettled in regard to whether CRP plays a causal role in the pathogenesis of atherosclerosis. METHODS AND RESULTS: We generated 2 lines of transgenic (Tg) rabbits expressing human CRP (hCRP). The plasma levels of hCRP in hCRP-Tg-1 and hCRP-Tg-2 rabbits were 0.4+/-0.13 (n=14) and 57.8+/-20.6 mg/L (n=12), respectively. In addition, hCRP isolated from Tg rabbit plasma exhibited the ability to activate the rabbit complement. To define the role of hCRP in atherosclerosis, we compared the susceptibility of hCRP-Tg rabbits to cholesterol-rich diet-induced aortic and coronary atherosclerosis with that of non-Tg rabbits. After being fed with a cholesterol-rich diet for 16 weeks, Tg and non-Tg rabbits developed similar hypercholesterolemia and lesion sizes in both aortic and coronary arteries. Immunohistochemical staining and Western blotting revealed that hCRP was indeed present in the lesions but did not affect macrophage accumulation and smooth muscle cell proliferation of the lesions. CONCLUSIONS: Neither high nor low plasma concentrations of hCRP affected aortic or coronary atherosclerosis lesion formation in hCRP-Tg rabbits.
Assuntos
Aterosclerose/etiologia , Proteína C-Reativa/fisiologia , Animais , Animais Geneticamente Modificados , Aterosclerose/diagnóstico , Biomarcadores , Proteína C-Reativa/análise , Colesterol na Dieta/administração & dosagem , Humanos , Masculino , CoelhosRESUMO
OBJECTIVE: Apolipoprotein AII (apoAII) is the second major apolipoprotein in high-density lipoprotein (HDL). However, the physiological functions of apoAII in lipoprotein metabolism have not been fully elucidated. METHODS AND RESULTS: We generated human apoAII transgenic (Tg) rabbits, a species that normally does not have an endogenous apoAII gene. Plasma levels of human apoAII in Tg rabbits were approximately 30 mg/dL, similar to the plasma levels in healthy humans. The expression of human apoAII in Tg rabbits resulted in increased levels of plasma triglycerides, total cholesterol, and phospholipids accompanied by a marked reduction in HDL-cholesterol levels compared with non-Tg littermates. Analysis of lipoprotein fractions showed that hyperlipidemia exhibited by Tg rabbits was caused by elevated levels of very-low-density lipoproteins (VLDL) and intermediate-density lipoproteins. Furthermore, postheparin lipoprotein lipase activity significantly decreased in Tg rabbits compared with non-Tg rabbits. CONCLUSIONS: These results indicate that apoAII plays an important role in both VLDL and HDL metabolism, possibly through the inhibition of lipoprotein lipase activity. ApoAII Tg rabbits may become a new model for the study of human familial combined hyperlipidemia.
Assuntos
Apolipoproteína A-II/sangue , Apolipoproteína A-II/genética , Hiperlipidemia Familiar Combinada/sangue , Hiperlipidemia Familiar Combinada/genética , Animais , Animais Geneticamente Modificados , Apolipoproteína A-II/metabolismo , Colesterol/sangue , HDL-Colesterol/sangue , Modelos Animais de Doenças , Expressão Gênica , Humanos , Hiperlipidemia Familiar Combinada/etiologia , Lipase Lipoproteica/sangue , Lipoproteínas IDL/sangue , Lipoproteínas VLDL/sangue , Fígado/metabolismo , Coelhos , Proteínas Recombinantes/sangue , Proteínas Recombinantes/genética , Triglicerídeos/sangueRESUMO
Nonalcoholic fatty liver disease (NAFLD) including nonalcoholic steatohepatitis (NASH) has reached epidemic proportions with no pharmacological therapy approved. Lower circulating glycine is consistently reported in patients with NAFLD, but the causes for reduced glycine, its role as a causative factor, and its therapeutic potential remain unclear. We performed transcriptomics in livers from humans and mice with NAFLD and found suppression of glycine biosynthetic genes, primarily alanine-glyoxylate aminotransferase 1 (AGXT1). Genetic (Agxt1 -/- mice) and dietary approaches to limit glycine availability resulted in exacerbated diet-induced hyperlipidemia and steatohepatitis, with suppressed mitochondrial/peroxisomal fatty acid ß-oxidation (FAO) and enhanced inflammation as the underlying pathways. We explored glycine-based compounds with dual lipid/glucose-lowering properties as potential therapies for NAFLD and identified a tripeptide (Gly-Gly-L-Leu, DT-109) that improved body composition and lowered circulating glucose, lipids, transaminases, proinflammatory cytokines, and steatohepatitis in mice with established NASH induced by a high-fat, cholesterol, and fructose diet. We applied metagenomics, transcriptomics, and metabolomics to explore the underlying mechanisms. The bacterial genus Clostridium sensu stricto was markedly increased in mice with NASH and decreased after DT-109 treatment. DT-109 induced hepatic FAO pathways, lowered lipotoxicity, and stimulated de novo glutathione synthesis. In turn, inflammatory infiltration and hepatic fibrosis were attenuated via suppression of NF-κB target genes and TGFß/SMAD signaling. Unlike its effects on the gut microbiome, DT-109 stimulated FAO and glutathione synthesis independent of NASH. In conclusion, impaired glycine metabolism may play a causative role in NAFLD. Glycine-based treatment attenuates experimental NAFLD by stimulating hepatic FAO and glutathione synthesis, thus warranting clinical evaluation.
Assuntos
Microbioma Gastrointestinal , Hepatopatia Gordurosa não Alcoólica , Animais , Dieta Hiperlipídica , Ácidos Graxos , Glutationa , Glicina , Humanos , Fígado , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológicoRESUMO
BACKGROUND AND AIMS: The development of serum markers specific for coronary lesions is important to prevent coronary events. However, analyses of serum markers in humans are affected by environmental factors and non-target diseases. Using an appropriate model animal can reduce these effects. To identify specific markers for coronary atherosclerosis, we comprehensively analyzed the serum of WHHLMI rabbits, which spontaneously develop coronary atherosclerosis. METHODS: Female WHHLMI rabbits were fed standard chow. Serum and plasma were collected under fasting at intervals of 4 months from 4 months old, and a total of 313 lipid molecules, 59 metabolites, lipoprotein lipid levels, and various plasma biochemical parameters were analyzed. The severity of coronary lesions was evaluated with cross-sectional narrowing (CSN) corrected with a frequency of 75%-89% CSN and CSN> 90%. RESULTS: There was a large variation in the severity of coronary lesions in WHHLMI rabbits despite almost no differences in plasma biochemical parameters and aortic lesion area between rabbits with severe and mild coronary lesions. The metabolites and lipid molecules selected as serum markers for coronary atherosclerosis were lysophosphatidylcholine (LPC) 22:4 and diacylglycerol 18:0-18:0â¯at 4 months old, LPC 20:4 (sn-2), ceramide d18:1-18:2, citric acid plus isocitric acid, and pyroglutamic acid at 8 months old, and phosphatidylethanolamine plasminogen 16:1p-22:2â¯at 16 months old. CONCLUSIONS: These serum markers were coronary lesion-specific markers independent of cholesterol levels and aortic lesions and may be useful to detect patients who develop cardiovascular disease.
Assuntos
Doença da Artéria Coronariana/sangue , Animais , Biomarcadores , Modelos Animais de Doenças , Progressão da Doença , Feminino , Hiperlipoproteinemia Tipo II , CoelhosRESUMO
AIMS: The relationship between the coronary artery running pattern and development of coronary lesions was re-examined herein using WHHLMI rabbits, an animal model of spontaneous coronary atherosclerosis. METHODS: The coronary artery running pattern was analyzed using an X-ray computed tomography (CT) apparatus after perfusion. Pathological sections were prepared (Victoria blue-HE staining) at 100 µm intervals from the origin of the left circumflex artery (LCX). The severity of coronary lesions was evaluated based on cross-sectional narrowing (lesion area/inner area of the internal elastic lamina). RESULTS: In the CT analysis, the angle of the main curvature of the LCX negatively correlated with the percentage of sections with lesions and cross-sectional narrowing. The percentage of sections with lesions was significantly higher in acute angle-type LCX than in obtuse angle-type LCX. Cross-sectional narrowing was also significantly greater in acute angle-type LCX than in obtuse angle-type LCX. The percentage of fibrous lesions was high at the proximal region of LCX, whereas that of lipid-rich lesions was high at the curvature. In 24 months age group, the percentage of sections with calcification in acute angle-type LCX was about twice that in obtuse angle-type LCX. CONCLUSIONS: Individual differences were observed in the angle of the main curvature of the LCX, which affected the occurrence and extension of atherosclerotic lesions.
Assuntos
Doença da Artéria Coronariana/patologia , Vasos Coronários/patologia , Modelos Animais de Doenças , Hipercolesterolemia/fisiopatologia , Índice de Gravidade de Doença , Animais , Doença da Artéria Coronariana/etiologia , Progressão da Doença , Feminino , Hipercolesterolemia/complicações , Masculino , Coelhos , Fatores de RiscoRESUMO
Improvements induced in lipid metabolism in the liver by D-47, a newly developed compound, were examined herein. WHHLMI rabbits, an animal model of hypercholesterolemia and coronary atherosclerosis, was fed D-47-supplemented chow for 5 weeks at a dose of 30mg/kg. Lipid concentration were assayed using enzymatic methods. Plasma lipoproteins were fractionated with an ultracentrifuge. mRNA expression was analyzed with real-time PCR. Lipidome analyses of lipoproteins were performed using supercritical fluid chromatography mass spectrometry. In the D-47-treated group, serum lipid levels decreased by 23% for total cholesterol and by 40% for triglycerides. These reductions were mainly attributed to decreases in the VLDL fraction. Compared with the control, in the D-47 group, lipid contents in the liver were decreased by 22% in cholesterol and by 69% in triglycerides, and fat accumulation was decreased by 57% in pericardial fat and by 17% in mesenteric fat. In lipidome analyses of VLDL fraction, lysophosphatidylcholine, phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylethanolamine plasmalogen, sphingomyelin, and ceramide were decreased by the D-47 treatment. mRNA expression in the liver was 51% lower for FAS and 24% lower for MTP, but 5.9- and 5.1-fold higher for CYP7A1 and CPT-1, respectively, in the D-47 group than in the control. mRNA expression was 72%, 64%, and 36% higher for LPL, CTP-1, and PPARγ, respectively, in mesenteric fat in the D-47 group. D-47 is a potent lipid-lowering compound that uses a different mechanism of action from that of statins. It has potential as a compound in the treatment of steatohepatitis and metabolic syndrome.
Assuntos
Desenho de Fármacos , Éteres de Hidroxibenzoatos/farmacologia , Hiperlipoproteinemia Tipo II/tratamento farmacológico , Hiperlipoproteinemia Tipo II/metabolismo , Hipolipemiantes/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Pirrolidinonas/farmacologia , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/metabolismo , Animais , Modelos Animais de Doenças , Éteres de Hidroxibenzoatos/uso terapêutico , Hiperlipoproteinemia Tipo II/genética , Hipolipemiantes/uso terapêutico , Lipoproteínas/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Pirrolidinonas/uso terapêutico , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , CoelhosRESUMO
BACKGROUND: Macrophage metalloelastase (matrix metalloproteinase [MMP]-12) is upregulated in atherosclerotic lesions and aneurysm; thus, increased MMP-12 activity may play an important role in the pathogenesis of atherosclerosis. However, the pathological roles of MMP-12 in the initiation and progression of atherosclerosis have not been defined. METHODS AND RESULTS: We compared the susceptibility of MMP-12 transgenic (Tg) rabbits to cholesterol-rich diet-induced atherosclerosis with that of non-Tg littermate rabbits. The rabbits were maintained at either relatively lower levels of hypercholesterolemia for shorter periods or higher levels of hypercholesterolemia for longer periods through a diet containing different amounts of cholesterol. We found no significant difference in the aortic atherosclerotic lesion size or quality between Tg and non-Tg rabbits at lower hypercholesterolemia. At higher hypercholesterolemia for longer periods, however, Tg rabbits developed more extensive atherosclerosis in the aortas and coronary arteries than did non-Tg rabbits. Histological examinations revealed that atherosclerotic lesions of Tg rabbits contained prominent macrophage infiltration associated with marked disruption of the elastic lamina in the tunica media with occasional formation of aneurysm-like lesions. Furthermore, increased expression of MMP-12 derived from macrophages was associated with elevated expression of MMP-3, suggesting that MMP-12 may play a pivotal role in the cascade activation of other MMPs, thereby exacerbating extracellular matrix degradation during the progression of atherosclerosis. CONCLUSIONS: Overexpression of MMP-12 causes accelerated atherosclerosis in Tg rabbits. These results suggest that macrophage-derived MMP-12 participates in the progression of atherosclerosis.
Assuntos
Aterosclerose/etiologia , Metaloendopeptidases/fisiologia , Animais , Animais Geneticamente Modificados , Movimento Celular , Doença da Artéria Coronariana/enzimologia , Humanos , Imuno-Histoquímica , Macrófagos/fisiologia , Metaloproteinase 12 da Matriz , Metaloproteinase 9 da Matriz/análise , Metaloproteinases da Matriz/análise , Metaloproteinases da Matriz Associadas à Membrana , Metaloendopeptidases/análise , Músculo Liso Vascular/patologia , CoelhosRESUMO
Elevated plasma levels of LDL and lipoprotein (a) [Lp(a)] are associated with an increased risk of atherosclerosis and coronary heart disease. However, it is not known whether Lp(a) would enhance the atherogenic effect of LDL on coronary atherosclerosis and myocardial infarction. To address this issue, we cross-bred human Lp(a) transgenic (Tg) rabbits with Watanabe heritable hyperlipidemic (WHHL) rabbits and evaluated the long-term (at the age of 2 years) effects of Lp(a) on the development of coronary atherosclerosis. Compared to non-Tg WHHL rabbits, Tg WHHL rabbits did not show significant changes in plasma total cholesterol, triglycerides, or HDL-C. However, Tg WHHL rabbits showed significantly larger lesions in the right coronary arteries (p<0.05). Immunohistochemical staining revealed that the lesions of Tg WHHL rabbits were enriched in the extracellular matrix contents whereas the cellular components were not different from those in non-Tg WHHL rabbits. Increased atherosclerosis in the coronary arteries in Tg WHHL rabbit hearts was also associated with a higher incidence of chronic ischemia and myocardial infarction. These results suggest that increased plasma levels of Lp(a) enhance coronary atherosclerosis and myocardial infarction in the setting of hypercholesterolemia.
Assuntos
Doença da Artéria Coronariana/fisiopatologia , Hiperlipidemias/fisiopatologia , Lipoproteína(a)/efeitos adversos , Infarto do Miocárdio/fisiopatologia , Animais , Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/patologia , Hiperlipidemias/sangue , Lipoproteína(a)/sangue , Infarto do Miocárdio/sangue , Infarto do Miocárdio/patologia , Organismos Geneticamente Modificados , CoelhosRESUMO
AIM: Abnormal lipid metabolism results in the alteration of lipid compositions in lipoproteins; therefore an accurate and quantitative analytical approach is required for the detailed structural characterization of lipoproteins. However, the specific lipid composition of each lipoprotein particle is poorly understood. MATERIALS & METHODS: Lipid composition of very-low-density lipoprotein and low-density lipoprotein particles derived from myocardial infarction-prone rabbits was determined by normalization of lipidomics data using apoB-100 levels. RESULTS: The ratio of lipid levels between very-low-density lipoprotein and low-density lipoprotein particles was different according to not only lipid classes, but also phosphatidylethanolamine subclasses by applying our developed methodology to myocardial infarction-prone rabbits. CONCLUSION: Our novel analytical approach represents to be a potentially useful tool to obtain particle-specific lipid components of lipoproteins.
Assuntos
Apolipoproteínas/análise , Lipoproteínas/análise , Espectrometria de Massas em Tandem/métodos , Animais , Apolipoproteína B-100/análise , Apolipoproteína B-100/sangue , Apolipoproteínas/sangue , Cromatografia Líquida/métodos , Feminino , Lipoproteínas/sangue , Lipoproteínas LDL/análise , Lipoproteínas LDL/sangue , Lipoproteínas VLDL/análise , Lipoproteínas VLDL/sangue , Masculino , Infarto do Miocárdio/sangue , Infarto do Miocárdio/patologia , CoelhosRESUMO
In order to examine their suitability for studies on coronary atherosclerosis, we evaluated the features of coronary atherosclerotic plaques in myocardial infarction-prone Watanabe heritable hyperlipidemic (WHHLMI) rabbits, a spontaneous animal model for coronary atherosclerosis and myocardial infarction. Coronary segments of the hearts of 187 WHHLMI rabbits (10-29 months old) were sectioned serially and stained histopathologically and immunohistologically. Progression of coronary lesions was prominent in rabbits that had died suddenly. The degree of coronary lesions of females was higher than that of males. Various types of atherosclerotic lesions were observed in the coronary arteries, such as plaques with a large lipid core covered by a thin fibrous cap, fatty streaks, early and advanced fibroatheromas, fibrous lesions, and advanced lesions with calcium accumulation and the vasa vasorum. In rabbits that had died suddenly, the frequencies of fibroatheromas or advanced lesions were higher than those of rabbits euthanized. Matrix metalloproteinase (MMP)-positive macrophages were detected in gaps among endothelial cells at the plaque surface, beneath the fibrous cap of thin-capped fibroatheromas, and at the bottom of the intimal plaques in which the tunica media was attenuated. Immunohistological results suggest that MMP-positive macrophages are involved in the initiation, progression, and destabilization of coronary plaques, in addition to vascular remodeling, even in WHHLMI rabbits. In conclusion, coronary lesions in WHHLMI rabbits resemble human atherosclerotic lesions, and thus, the WHHLMI rabbit is a suitable animal model for studies on human coronary plaques.
Assuntos
Doença da Artéria Coronariana/patologia , Vasos Coronários/patologia , Modelos Animais de Doenças , Hiperlipoproteinemia Tipo II/patologia , Placa Aterosclerótica/patologia , Animais , Feminino , Humanos , Macrófagos/enzimologia , Macrófagos/patologia , Masculino , Metaloproteinases da Matriz/metabolismo , Coelhos , Túnica Média/patologiaRESUMO
OBJECTIVE: This study was designed to address the effects of increased lipoprotein lipase (LPL) activity on atherosclerosis in the setting of LDL receptor deficiency. METHODS: We generated transgenic (Tg) Watanabe heritable hyperlipidemic (WHHL) rabbits overexpressing human LPL and compared their plasma lipids and aortic atherosclerosis with non-Tg WHHL rabbits. RESULTS: Increased expression of LPL significantly ameliorated hypertriglyceridemia and hypercholesterolemia in Tg WHHL rabbits [64% reduction in total cholesterol (TC) and 91% reduction in triglycerides (TG) vs. non-Tg]. In spite of this beneficial effect of LPL, Tg WHHL rabbits had two-fold greater aortic atherosclerosis than non-Tg WHHL rabbits. Analysis of plasma lipoprotein profiles revealed that increased LPL activity in Tg WHHL rabbits resulted in the dramatic reduction of large TG-rich lipoproteins (VLDL, d<1.006 g/ml and IDL, d=1.006-1.02) but concomitant increases in LDL fractions, especially those of small and dense LDL particles (d=1.04-1.06, 2.6-fold over non-Tg). Using apoB-containing lipoproteins, we found that small-sized LDL from Tg WHHL rabbits contained more oxidizable substrate and exhibited higher affinity to biglycan than large TG-rich LDL of non-Tg WHHL rabbits. CONCLUSIONS: We conclude that in the absence of LDL receptor function, increased LPL activity accelerates the catabolism of large TG-rich VLDL (possibly via the LRP pathway) and subsequently improves hyperlipidemia. However, LPL may also enhance the generation and accumulation of small dense LDLs, which are more atherogenic.
Assuntos
Doenças da Aorta/enzimologia , Arteriosclerose/enzimologia , Hiperlipidemias/enzimologia , Lipase Lipoproteica/genética , Animais , Animais Geneticamente Modificados , Aorta/patologia , Doenças da Aorta/sangue , Doenças da Aorta/patologia , Apolipoproteínas B/análise , Arteriosclerose/sangue , Arteriosclerose/patologia , Colesterol/sangue , LDL-Colesterol/sangue , VLDL-Colesterol/sangue , Feminino , Humanos , Hiperlipidemias/patologia , Processamento de Imagem Assistida por Computador , Lipase Lipoproteica/sangue , Lipoproteínas/metabolismo , Masculino , Microscopia Eletrônica , Coelhos , Triglicerídeos/sangueRESUMO
We examined the relationship between atherosclerosis and the provocation of coronary spasm as well as the influence of coronary spasm on the onset of acute ischemic myocardial disease. Coronary spasm was provoked in anesthetized normal Japanese white (JW) rabbits and myocardial infarction-prone Watanabe heritable hyperlipidemic (WHHLMI) rabbits, an animal model for coronary atherosclerosis and myocardial infarction, by injecting ergonovine during the infusion of norepinephrine through a marginal ear vein. A decrease in contrast flow in the left circumflex artery was observed on coronary angiograms. Ischemic changes were observed on the electrocardiograms of 29% (2/7) of JW and 79% (27/34, P=0.007) of WHHLMI rabbits. The frequency of coronary spasm was significantly high in rabbits with severe coronary plaques showing diffuse lesions. Left ventricle motility in vasospasm-positive rabbits, which was evaluated with echocardiograms, was decreased by 29% following the ergonovine injection (P<0.001), and every serum ischemic marker markedly increased 4 h after the provocation of vasospasm. These results demonstrate that atherosclerotic coronary arteries are positively related to the provocation of vasospasm, and vasospasm in severe atherosclerotic coronary segments evokes angina pectoris-like findings and/or non-fatal myocardial infarction. WHHLMI rabbits may be a novel animal model for angina pectoris and acute ischemic heart disease.