RESUMO
BACKGROUND: Galectins have numerous cellular functions in immunity and inflammation. Short-term galectin-2 (Gal-2) blockade in ischemia-induced arteriogenesis shifts macrophages to an anti-inflammatory phenotype and improves perfusion. Gal-2 may also affect other macrophage-related cardiovascular diseases. OBJECTIVES: This study aims to elucidate the effects of Gal-2 inhibition in atherosclerosis. METHODS: ApoE -/- mice were given a high-cholesterol diet (HCD) for 12 weeks. After 6 weeks of HCD, intermediate atherosclerotic plaques were present. To study the effects of anti-Gal-2 nanobody treatment on the progression of existing atherosclerosis, treatment with two llama-derived anti-Gal-2 nanobodies (clones 2H8 and 2C10), or vehicle was given for the remaining 6 weeks. RESULTS: Gal-2 inhibition reduced the progression of existing atherosclerosis. Atherosclerotic plaque area in the aortic root was decreased, especially so in mice treated with 2C10 nanobodies. This clone showed reduced atherosclerosis severity as reflected by a decrease in fibrous cap atheromas in addition to decreases in plaque size.The number of plaque resident macrophages was unchanged; however, there was a significant increase in the fraction of CD206+ macrophages. 2C10 treatment also increased plaque α-smooth muscle content, and Gal-2 may have a role in modulating the inflammatory status of smooth muscle cells. Remarkably, both treatments reduced serum cholesterol concentrations including reductions in very low-density lipoprotein, low-density lipoprotein, and high-density lipoprotein while triglyceride concentrations were unchanged. CONCLUSION: Prolonged and frequent treatment with anti-Gal-2 nanobodies reduced plaque size, slowed plaque progression, and modified the phenotype of plaque macrophages toward an anti-inflammatory profile. These results hold promise for future macrophage modulating therapeutic interventions that promote arteriogenesis and reduce atherosclerosis.
Assuntos
Aterosclerose , Hiperlipidemias , Placa Aterosclerótica , Anticorpos de Domínio Único , Animais , Anti-Inflamatórios/uso terapêutico , Apolipoproteínas E , Aterosclerose/genética , Colesterol , Modelos Animais de Doenças , Galectina 2/farmacologia , Galectina 2/uso terapêutico , Macrófagos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Knockout para ApoERESUMO
Background In the presence of arterial stenosis, collateral artery growth (arteriogenesis) can alleviate ischemia and preserve tissue function. In patients with poorly developed collateral arteries, Gal-2 (galectin 2) expression is increased. In vivo administration of Gal-2 inhibits arteriogenesis. Blocking of Gal-2 potentially stimulates arteriogenesis. This study aims to investigate the effect of Gal-2 inhibition on arteriogenesis and macrophage polarization using specific single-domain antibodies. Methods and Results Llamas were immunized with Gal-2 to develop anti-Gal-2 antibodies. Binding of Gal-2 to monocytes and binding inhibition of antibodies were quantified. To test arteriogenesis in vivo, Western diet-fed LDLR.(low-density lipoprotein receptor)-null Leiden mice underwent femoral artery ligation and received treatment with llama antibodies 2H8 or 2C10 or with vehicle. Perfusion restoration was measured with laser Doppler imaging. In the hind limb, arterioles and macrophage subtypes were characterized by histology, together with aortic atherosclerosis. Llama-derived antibodies 2H8 and 2C10 strongly inhibited the binding of Gal-2 to monocytes (93% and 99%, respectively). Treatment with these antibodies significantly increased perfusion restoration at 14 days (relative to sham, vehicle: 41.3±2.7%; 2H8: 53.1±3.4%, P=0.016; 2C10: 52.0±3.8%, P=0.049). In mice treated with 2H8 or 2C10, the mean arteriolar diameter was larger compared with control (vehicle: 17.25±4.97 µm; 2H8: 17.71±5.01 µm; 2C10: 17.84±4.98 µm; P<0.001). Perivascular macrophages showed a higher fraction of the M2 phenotype in both antibody-treated animals (vehicle: 0.49±0.24; 2H8: 0.73±0.15, P=0.007; 2C10: 0.75±0.18, P=0.006). In vitro antibody treatment decreased the expression of M1-associated cytokines compared with control (P<0.05 for each). Atherosclerotic lesion size was comparable between groups (overall P=0.59). Conclusions Inhibition of Gal-2 induces a proarteriogenic M2 phenotype in macrophages, improves collateral artery growth, and increases perfusion restoration in a murine hind limb model.
Assuntos
Anticorpos/farmacologia , Aterosclerose/metabolismo , Circulação Colateral/fisiologia , Artéria Femoral/metabolismo , Galectina 2/antagonistas & inibidores , Membro Posterior/irrigação sanguínea , Animais , Aterosclerose/patologia , Aterosclerose/fisiopatologia , Modelos Animais de Doenças , Feminino , Artéria Femoral/fisiopatologia , Galectina 2/metabolismo , Humanos , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transdução de SinaisRESUMO
Monocytes are involved in adverse left ventricular (LV) remodelling following myocardial infarction (MI). To provide therapeutic opportunities we aimed to identify gene transcripts in monocytes that relate to post-MI healing and evaluated intervention with the observed gene activity in a rat MI model. In 51 MI patients treated by primary percutaneous coronary intervention (PCI), the change in LV end-diastolic volume index (EDVi) from baseline to 4-month follow-up was assessed using cardiovascular magnetic resonance imaging (CMR). Circulating monocytes were collected at day 5 (Arterioscler Thromb Vasc Biol 35:1066-1070, 2015; Cell Stem Cell 16:477-487, 2015; Curr Med Chem 13:1877-1893, 2006) after primary PCI for transcriptome analysis. Transcriptional profiling and pathway analysis revealed that patients with a decreased LV EDVi showed an induction of type I interferon (IFN) signalling (type I IFN pathway: P value < 0.001; false discovery rate < 0.001). We subsequently administered 15,000 Units of IFN-α subcutaneously in a rat MI model for three consecutive days following MI. Cardiac function was measured using echocardiography and infarct size/cardiac inflammation using (immuno)-histochemical analysis. We found that IFN-α application deteriorated ventricular dilatation and increased infarct size at day 28 post-MI. Moreover, IFN-α changed the peripheral monocyte subset distribution towards the pro-inflammatory monocyte subset whereas in the myocardium, the presence of the alternative macrophage subset was increased at day 3 post-MI. Our findings suggest that induction of type I IFN signalling in human monocytes coincides with adverse LV remodelling. In rats, however, IFN-α administration deteriorated post-MI healing. These findings underscore important but also contradictory roles for the type I IFN response during cardiac healing following MI.
Assuntos
Interferon Tipo I/metabolismo , Monócitos/transplante , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/terapia , Remodelação Ventricular , Adulto , Idoso , Animais , Transplante de Medula Óssea/métodos , Feminino , Humanos , Interferon Tipo I/farmacologia , Masculino , Pessoa de Meia-Idade , Monócitos/metabolismo , Infarto do Miocárdio/patologia , Ratos , Ratos Wistar , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Remodelação Ventricular/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Cicatrização/fisiologiaRESUMO
Coronary artery disease (CAD), also known as ischemic heart disease (IHD), is the leading cause of mortality in the western world, with developing countries showing a similar trend. With the increased understanding of the role of the immune system and inflammation in coronary artery disease, it was shown that macrophages play a major role in this disease. Costimulatory molecules are important regulators of inflammation, and especially, the CD40L-CD40 axis is of importance in the pathogenesis of cardiovascular disease. Although it was shown that CD40 can mediate macrophage function, its exact role in macrophage biology has not gained much attention in cardiovascular disease. Therefore, the goal of this review is to give an overview on the role of macrophage-specific CD40 in cardiovascular disease, with a focus on coronary artery disease. We will discuss the function of CD40 on the macrophage and its (proposed) role in the reduction of atherosclerosis, the reduction of neointima formation, and the stimulation of arteriogenesis.
Assuntos
Antígenos CD40/imunologia , Doença da Artéria Coronariana/patologia , Macrófagos/patologia , Animais , Doença da Artéria Coronariana/imunologia , Humanos , Macrófagos/imunologiaRESUMO
Galectins are an ancient family of ß-galactoside-specific lectins and consist of 15 different types, each with a specific function. They play a role in the immune system, inflammation, wound healing and carcinogenesis. In particular the role of galectin in cancer is widely studied. Lately, the role of galectins in the development of cardiovascular disease has gained attention. Worldwide cardiovascular disease is still the leading cause of death. In ischemic heart disease, atherosclerosis limits adequate blood flow. Angiogenesis and arteriogenesis are highly important mechanisms relieving ischemia by restoring perfusion to the post-stenotic myocardial area. Galectins act ambiguous, both relieving ischemia and accelerating atherosclerosis. Atherosclerosis can ultimately lead to myocardial infarction or ischemic stroke, which are both associated with galectins. There is also a role for galectins in the development of myocarditis by their influence on inflammatory processes. Moreover, galectin acts as a biomarker for the severity of myocardial ischemia and heart failure. This review summarizes the association between galectins and the development of multiple cardiovascular diseases such as myocarditis, ischemic stroke, myocardial infarction, heart failure and atrial fibrillation. Furthermore it focuses on the association between galectin and more general mechanisms such as angiogenesis, arteriogenesis and atherosclerosis.
Assuntos
Doenças Cardiovasculares/metabolismo , Galectinas/metabolismo , Animais , Biomarcadores/metabolismo , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/fisiopatologia , Humanos , Neovascularização Patológica , Neovascularização Fisiológica , Valor Preditivo dos Testes , Prognóstico , Índice de Gravidade de Doença , Transdução de SinaisRESUMO
The flow-responsive transcription factor Krüppel-like factor 2 (KLF2) maintains an anti-coagulant, anti-inflammatory endothelium with sufficient nitric oxide (NO)-bioavailability. In this study, we aimed to explore, both in vitro and in human vascular tissue, expression of the NO-transporting transmembrane pore aquaporin-1 (AQP1) and its regulation by atheroprotective KLF2 and atherogenic inflammatory stimuli. In silico analysis of gene expression profiles from studies that assessed the effects of KLF2 overexpression in vitro and atherosclerosis in vivo on endothelial cells, identifies AQP1 as KLF2 downstream gene with elevated expression in the plaque-free vessel wall. Biomechanical and pharmaceutical induction of KLF2 in vitro is accompanied by induction of AQP1. Chromosome immunoprecipitation (CHIP) confirms binding of KLF2 to the AQP1 promoter. Inflammatory stimulation of endothelial cells leads to repression of AQP1 transcription, which is restrained by KLF2 overexpression. Immunohistochemistry reveals expression of aquaporin-1 in non-activated endothelium overlying macrophage-poor intimae, irrespective whether these intimae are characterized as being plaque-free or as containing advanced plaque. We conclude that AQP1 expression is subject to KLF2-mediated positive regulation by atheroprotective shear stress and is downregulated under inflammatory conditions both in vitro and in vivo. Thus, endothelial expression of AQP1 characterizes the atheroprotected, non-inflamed vessel wall. Our data provide support for a continuous role of KLF2 in stabilizing the vessel wall via co-temporal expression of eNOS and AQP1 both preceding and during the pathogenesis of atherosclerosis.
Assuntos
Aquaporina 1/metabolismo , Endotélio Vascular/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Óxido Nítrico/metabolismo , Aquaporina 1/genética , Transporte Biológico/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Imuno-Histoquímica , Mediadores da Inflamação/farmacologia , Fatores de Transcrição Kruppel-Like/genética , Placa Aterosclerótica/patologia , Regiões Promotoras Genéticas/genética , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Estresse Mecânico , Transcrição Gênica/efeitos dos fármacos , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
A defect in neo-vascularization process involving circulating angiogenic mononuclear cells (CACs) dysfunction is associated with diabetes. We showed that oxidative stress was elevated in CACs cultured from blood of individuals with metabolic syndrome (MetS) and diabetes. We then assessed the action of palmitic acid (PA), a deregulated and increased NEFA in metabolic disorders, focusing on its oxidant potential. We observed that the phyto-polyphenol resveratrol normalized oxidative stress both in CACs isolated from MetS patients or treated with PA. Resveratrol further decreased the deleterious action of PA on gene expression of vascularization factors (TNFα, VEGF-A, SDF1α, PECAM-1, VEGFR2, Tie2 and CXCR4) and improved CAC motility. Particularly, resveratrol abolished the PA-induced over-expression of the pro-oxidant protein p66Shc. Neither KLF2 nor SIRT1, previously shown in resveratrol and p66Shc action, was directly involved. Silencing p66Shc normalized PA action on VEGF-A and TNFα specifically, without abolishing the PA-induced oxidative stress, which suggests a deleterious role of p66Shc independently of any major modulation of the cellular oxidative status in a high NEFA levels context. Besides showing that resveratrol reverses PA-induced harmful effects on human CAC function, certainly through profound cellular modifications, we establish p66Shc as a major therapeutic target in metabolic disorders, independent from glycemic control.
Assuntos
Estresse Oxidativo/efeitos dos fármacos , Ácido Palmítico/metabolismo , Proteínas Adaptadoras da Sinalização Shc/genética , Estilbenos/farmacologia , Antioxidantes/farmacologia , Estudos de Casos e Controles , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Diabetes Mellitus Tipo 2/fisiopatologia , Regulação da Expressão Gênica/efeitos dos fármacos , Inativação Gênica , Humanos , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Masculino , Síndrome Metabólica/fisiopatologia , Pessoa de Meia-Idade , Neovascularização Fisiológica/efeitos dos fármacos , Resveratrol , Proteína 1 de Transformação que Contém Domínio 2 de Homologia de SrcRESUMO
AIMS: IFN-beta (IFNß) signalling is increased in patients with insufficient coronary collateral growth (i.e. arteriogenesis) and IFNß hampers arteriogenesis in mice. A downside of most pro-arteriogenic agents investigated in the past has been their pro-atherosclerotic properties, rendering them unsuitable for therapeutic application. Interestingly, type I IFNs have also been identified as pro-atherosclerotic cytokines and IFNß treatment increases plaque formation and accumulation of macrophages. We therefore hypothesized that mAb therapy to inhibit IFNß signalling would stimulate arteriogenesis and simultaneously attenuate-rather than aggravate-atherosclerosis. METHODS AND RESULTS: In a murine hindlimb ischaemia model, atherosclerotic low-density lipoprotein receptor knockout (LDLR(-/-)) mice were treated during a 4-week period with blocking MAbs specific for mouse IFN-α/ß receptor subunit 1 (IFNAR1) or murine IgG isotype as a control. The arteriogenic response was quantified using laser Doppler perfusion imaging (LDPI) as well as immunohistochemistry. Effects on atherosclerosis were determined by quantification of plaque area and analysis of plaque composition. Downstream targets of IFNß were assessed by real-time PCR (RT-PCR) in the aortic arch. Hindlimb perfusion restoration after femoral artery ligation was improved in mice treated with anti-IFNAR1 compared with controls as assessed by LDPI. This was accompanied by a decrease in CXCL10 expression in the IFNAR1 MAb-treated group. Anti-IFNAR1 treatment reduced plaque apoptosis without affecting total plaque area or other general plaque composition parameters. Results were confirmed in a short-term model and in apolipoprotein E knockout (APOE)(-/-) mice. CONCLUSION: Monoclonal anti-IFNAR1 therapy during a 4-week treatment period stimulates collateral artery growth in mice and did not enhance atherosclerotic burden. This is the first reported successful strategy using MAbs to stimulate arteriogenesis.
Assuntos
Anticorpos Monoclonais/uso terapêutico , Aterosclerose/tratamento farmacológico , Artéria Femoral/imunologia , Membro Posterior/efeitos dos fármacos , Membro Posterior/imunologia , Isquemia/tratamento farmacológico , Receptor de Interferon alfa e beta/imunologia , Animais , Anticorpos Monoclonais/imunologia , Aterosclerose/metabolismo , Circulação Colateral/efeitos dos fármacos , Modelos Animais de Doenças , Artéria Femoral/fisiologia , Membro Posterior/irrigação sanguínea , Isquemia/imunologia , Isquemia/metabolismo , Macrófagos/imunologia , Camundongos Knockout , Monócitos/metabolismoRESUMO
Galectin-2 is a monocyte-expressed carbohydrate-binding lectin, for which increased expression is genetically determined and associated with decreased collateral arteriogenesis in obstructive coronary artery disease patients. The inhibiting effect of galectin-2 on arteriogenesis was confirmed in vivo, but the mechanism is largely unknown. In this study we aimed to explore the effects of galectin-2 on monocyte/macrophage phenotype in vitro and vivo, and to identify the receptor by which galectin-2 exerts these effects. We now show that the binding of galectin-2 to different circulating human monocyte subsets is dependent on monocyte surface expression levels of CD14. The high affinity binding is blocked by an anti-CD14 antibody but not by carbohydrates, indicating a specific protein-protein interaction. Galectin-2 binding to human monocytes modulated their transcriptome by inducing proinflammatory cytokines and inhibiting pro-arteriogenic factors, while attenuating monocyte migration. Using specific knock-out mice, we show that galectin-2 acts through the CD14/toll-like receptor (TLR)-4 pathway. Furthermore, galectin-2 skews human macrophages to a M1-like proinflammatory phenotype, characterized by a reduced motility and expression of an anti-arteriogenic cytokine/growth factor repertoire. This is accompanied by a switch in surface protein expression to CD40-high and CD206-low (M1). In a murine model we show that galectin-2 administration, known to attenuate arteriogenesis, leads to increased numbers of CD40-positive (M1) and reduced numbers of CD206-positive (M2) macrophages surrounding actively remodeling collateral arteries. In conclusion galectin-2 is the first endogenous CD14/TLR4 ligand that induces a proinflammatory, non-arteriogenic phenotype in monocytes/macrophages. Interference with CD14-Galectin-2 interaction may provide a new intervention strategy to stimulate growth of collateral arteries in genetically compromised cardiovascular patients.
Assuntos
Circulação Colateral/fisiologia , Galectina 2/fisiologia , Inflamação/fisiopatologia , Macrófagos/fisiologia , Monócitos/fisiologia , Animais , Antígenos CD40/biossíntese , Diferenciação Celular , Células Cultivadas , Circulação Colateral/efeitos dos fármacos , Células Dendríticas/metabolismo , Galectina 2/deficiência , Galectina 2/genética , Galectina 2/farmacologia , Regulação da Expressão Gênica , Humanos , Lectinas Tipo C/biossíntese , Receptores de Lipopolissacarídeos/imunologia , Receptores de Lipopolissacarídeos/fisiologia , Macrófagos/classificação , Macrófagos/efeitos dos fármacos , Receptor de Manose , Lectinas de Ligação a Manose/biossíntese , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Monócitos/efeitos dos fármacos , Fenótipo , Ligação Proteica/efeitos dos fármacos , Células RAW 264.7 , Receptores de Superfície Celular/biossíntese , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes de Fusão/farmacologia , Transdução de Sinais , Linfócitos T/metabolismo , Receptor 4 Toll-Like/metabolismoRESUMO
In this review we discuss the current literature on the effects of type I interferons (IFN) and their downstream effectors on vascular growth in experimental models in vitro and in vivo. In addition to its well-documented role in angiogenesis, that is, the growth of new capillaries from existing vessels, we will also describe emerging evidence and mechanisms by which type I IFN may inhibit arteriogenesis, that is, the expansive remodeling of existing collateral arteries. Crucial in both processes is the common role of circulating monocytes, which are known to act as pivotal cellular modulators in revascularization through secreted chemokines, proteases, and growth factors. These secreted molecules, which are all modulated by IFN signaling, act via degradation of the extracellular matrix and by stimulating the proliferation of vascular smooth muscle cells and endothelial cells. Thus, next to the antiviral and immunomodulatory activities of type I IFNs, a potent role of IFN-ß as modulator of revascularization is now emerging and may be considered a potential clinical target for the stimulation of angiogenesis and arteriogenesis in ill-perfused tissues.
Assuntos
Estenose da Valva Aórtica/metabolismo , Interferon beta/farmacologia , Morfogênese/efeitos dos fármacos , Isquemia Miocárdica/metabolismo , Neovascularização Fisiológica/efeitos dos fármacos , Animais , Estenose da Valva Aórtica/imunologia , Estenose da Valva Aórtica/patologia , Artérias/citologia , Artérias/efeitos dos fármacos , Artérias/imunologia , Proliferação de Células/efeitos dos fármacos , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/imunologia , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/imunologia , Matriz Extracelular/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/imunologia , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Interferon beta/genética , Interferon beta/imunologia , Monócitos/citologia , Monócitos/efeitos dos fármacos , Monócitos/imunologia , Músculo Liso Vascular/citologia , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/imunologia , Isquemia Miocárdica/imunologia , Isquemia Miocárdica/patologia , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/imunologiaRESUMO
BACKGROUND: Peroxisome proliferator-activated receptor-γ (PPARγ) agonists, which have been used as insulin sensitizers in diabetic patients, may improve functions of endothelial cells (ECs). We investigated the effect of PPARγ on angiogenic activities of murine ECs and bone marrow-derived proangiogenic cells (PACs). METHODS: PACs were isolated from bone marrow of 10-12 weeks old, wild type, db/db and PPARγ heterozygous animals. Cells were cultured on fibronectin and gelatin coated dishes in EGM-2MV medium. For in vitro stimulations, rosiglitazone (10 µmol/L) or GW9662 (10 µmol/L) were added to 80% confluent cell cultures for 24 hours. Angiogenic potential of PACs and ECs was tested in vitro and in vivo in wound healing assay and hind limb ischemia model. RESULTS: ECs and PACs isolated from diabetic db/db mice displayed a reduced angiogenic potential in ex vivo and in vitro assays, the effect partially rescued by incubation of cells with rosiglitazone (PPARγ activator). Correction of diabetes by administration of rosiglitazone in vivo did not improve angiogenic potential of isolated PACs or ECs. In a hind limb ischemia model we demonstrated that local injection of conditioned media harvested from wild type PACs improved the blood flow restoration in db/db mice, confirming the importance of paracrine action of the bone marrow-derived cells. CONCLUSIONS: In summary, activation of PPARγ by rosiglitazone improves angiogenic potential of diabetic ECs and PACs, but decreased expression of PPARγ in diabetes does not impair angiogenesis.
Assuntos
Células da Medula Óssea/citologia , Medula Óssea/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , PPAR gama/metabolismo , Células-Tronco/metabolismo , Animais , Células da Medula Óssea/efeitos dos fármacos , Células Cultivadas , Células Endoteliais/metabolismo , Hipoglicemiantes/farmacologia , Isquemia/tratamento farmacológico , Camundongos Endogâmicos C57BL , Neovascularização Fisiológica/efeitos dos fármacos , PPAR gama/genética , Rosiglitazona , Células-Tronco/citologia , Células-Tronco/efeitos dos fármacos , Tiazolidinedionas/farmacologia , Cicatrização/efeitos dos fármacosRESUMO
Acute myocardial infarction (AMI) is accompanied by increased expression of Toll like receptors (TLR)-2 and TLR4 on circulating monocytes. In animal models, blocking TLR2/4 signaling reduces inflammatory cell influx and infarct size. The clinical consequences of TLR activation during AMI in humans are unknown, including its role in long-term cardiac functional outcome Therefore, we analyzed gene expression in whole blood samples from 28 patients with an acute ST elevation myocardial infarction (STEMI), enrolled in the EXenatide trial for AMI patients (EXAMI), both at admission and after 4-month follow-up, by whole genome expression profiling and real-time PCR. Cardiac function was determined by cardiac magnetic resonance (CMR) imaging at baseline and after 4-month follow-up. TLR pathway activation was shown by increased expression of TLR4 and its downstream genes, including IL-18R1, IL-18R2, IL-8, MMP9, HIF1A, and NFKBIA. In contrast, expression of the classical TLR-induced genes, TNF, was reduced. Bioinformatics analysis and in vitro experiments explained this noncanonical TLR response by identification of a pivotal role for HIF-1α. The extent of TLR activation and IL-18R1/2 expression in circulating cells preceded massive troponin-T release and correlated with the CMR-measured ischemic area (R=0.48, p=0.01). In conclusion, we identified a novel HIF-1-dependent noncanonical TLR activation pathway in circulating leukocytes leading to enhanced IL-18R expression which correlated with the magnitude of the ischemic area. This knowledge may contribute to our mechanistic understanding of the involvement of the innate immune system during STEMI and may yield diagnostic and prognostic value for patients with myocardial infarction.
Assuntos
Interleucina-18/metabolismo , Infarto do Miocárdio/fisiopatologia , Receptor 4 Toll-Like/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Humanos , Interleucina-18/sangue , Interleucina-18/genética , Leucócitos/metabolismo , Pessoa de Meia-Idade , Receptor 4 Toll-Like/sangue , Receptor 4 Toll-Like/genética , Regulação para CimaRESUMO
The formation of collateral vessels (arteriogenesis) to sustain perfusion in ischemic tissue is native to the body and can compensate for coronary stenosis. However, arteriogenesis is a complex process and is dependent on many different factors. Although animal studies on collateral formation and stimulation show promising data, clinical trials have failed to replicate these results. Further research to the exact mechanisms is needed in order to develop a pharmalogical stimulant. This review gives an overview of recent data in the field of arteriogenesis.
Assuntos
Circulação Colateral/fisiologia , Doença da Artéria Coronariana/fisiopatologia , Neovascularização Fisiológica/fisiologia , Indutores da Angiogênese/uso terapêutico , Inibidores da Angiogênese/uso terapêutico , Animais , Bradicinina/fisiologia , Circulação Coronária/fisiologia , Vasos Coronários/fisiologia , Modelos Animais de Doenças , Fator Estimulador de Colônias de Granulócitos/fisiologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/fisiologia , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/fisiologia , Macrófagos/fisiologia , Camundongos , Monócitos/fisiologia , Músculo Liso Vascular/fisiologia , Neurregulinas/fisiologia , Plasma Rico em Plaquetas/fisiologia , Receptores da Bradicinina/fisiologia , Transdução de Sinais/fisiologia , Células-Tronco/fisiologia , Fator A de Crescimento do Endotélio Vascular/fisiologia , Vasodilatadores/uso terapêuticoRESUMO
AIMS: Monocytes are critical mediators of healing following acute myocardial infarction (AMI), making them an interesting target to improve myocardial repair. The purpose of this study was a gain of insight into the source and recruitment of monocytes following AMI in humans. METHODS AND RESULTS: Post-mortem tissue specimens of myocardium, spleen and bone marrow were collected from 28 patients who died at different time points after AMI. Twelve patients who died from other causes served as controls. The presence and localization of monocytes (CD14(+) cells), and their CD14(+)CD16(-) and CD14(+)CD16(+) subsets, were evaluated by immunohistochemical and immunofluorescence analyses. CD14(+) cells localized at distinct regions of the infarcted myocardium in different phases of healing following AMI. In the inflammatory phase after AMI, CD14(+) cells were predominantly located in the infarct border zone, adjacent to cardiomyocytes, and consisted for 85% (78-92%) of CD14(+)CD16(-) cells. In contrast, in the subsequent post-AMI proliferative phase, massive accumulation of CD14(+) cells was observed in the infarct core, containing comparable proportions of both the CD14(+)CD16(-) [60% (31-67%)] and CD14(+)CD16(+) subsets [40% (33-69%)]. Importantly, in AMI patients, of the number of CD14(+) cells was decreased by 39% in the bone marrow and by 58% in the spleen, in comparison with control patients (P = 0.02 and <0.001, respectively). CONCLUSIONS: Overall, this study showed a unique spatiotemporal pattern of monocyte accumulation in the human myocardium following AMI that coincides with a marked depletion of monocytes from the spleen, suggesting that the human spleen contains an important reservoir function for monocytes.
Assuntos
Monócitos/fisiologia , Infarto do Miocárdio/patologia , Baço/fisiologia , Idoso , Antígenos CD/metabolismo , Células da Medula Óssea/fisiologia , Estudos de Casos e Controles , Feminino , Humanos , Imuno-Histoquímica , Masculino , Monócitos/classificação , Infarto do Miocárdio/imunologia , Miocárdio/patologia , Baço/imunologiaRESUMO
AIMS: Heme oxygenase-1 (HO-1) is a cytoprotective enzyme that can be down-regulated in diabetes. Its importance for mature endothelium has been described, but its role in proangiogenic progenitors is not well known. We investigated the effect of HO-1 on the angiogenic potential of bone marrow-derived cells (BMDCs) and on blood flow recovery in ischemic muscle of diabetic mice. RESULTS: Lack of HO-1 decreased the number of endothelial progenitor cells (Lin(-)CD45(-)cKit(-)Sca-1(+)VEGFR-2(+)) in murine bone marrow, and inhibited the angiogenic potential of cultured BMDCs, affecting their survival under oxidative stress, proliferation, migration, formation of capillaries, and paracrine proangiogenic potential. Transcriptome analysis of HO-1(-/-) BMDCs revealed the attenuated up-regulation of proangiogenic genes in response to hypoxia. Heterozygous HO-1(+/-) diabetic mice subjected to hind limb ischemia exhibited reduced local expression of vascular endothelial growth factor (VEGF), placental growth factor (PlGF), stromal cell-derived factor 1 (SDF-1), VEGFR-1, VEGFR-2, and CXCR-4. This was accompanied by impaired revascularization of ischemic muscle, despite a strong mobilization of bone marrow-derived proangiogenic progenitors (Sca-1(+)CXCR-4(+)) into peripheral blood. Blood flow recovery could be rescued by local injections of conditioned media harvested from BMDCs, but not by an injection of cultured BMDCs. INNOVATION: This is the first report showing that HO-1 haploinsufficiency impairs tissue revascularization in diabetes and that proangiogenic in situ response, not progenitor cell mobilization, is important for blood flow recovery. CONCLUSIONS: HO-1 is necessary for a proper proangiogenic function of BMDCs. A low level of HO-1 in hyperglycemic mice decreases restoration of perfusion in ischemic muscle, which can be rescued by a local injection of conditioned media from cultured BMDCs.
Assuntos
Células da Medula Óssea/fisiologia , Heme Oxigenase-1/fisiologia , Proteínas de Membrana/fisiologia , Neovascularização Fisiológica , Células-Tronco/fisiologia , Animais , Apoptose , Movimento Celular , Proliferação de Células , Células Cultivadas , Feminino , Haploinsuficiência , Membro Posterior/irrigação sanguínea , Hiperglicemia/metabolismo , Isquemia/enzimologia , Masculino , Camundongos , Camundongos Knockout , Regeneração , Transplante de Células-Tronco , TranscriptomaAssuntos
Peptídeo 1 Semelhante ao Glucagon , Infarto do Miocárdio/sangue , Infarto do Miocárdio/tratamento farmacológico , Peptídeos/administração & dosagem , Intervenção Coronária Percutânea , Peçonhas/administração & dosagem , Administração Intravenosa , Idoso , Exenatida , Estudos de Viabilidade , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/cirurgia , Intervenção Coronária Percutânea/métodos , Resultado do TratamentoRESUMO
BACKGROUND: Episodes of microvascular proliferation associated with volume expansion have been observed in arteriovenous malformations (AVMs) of skin and soft tissue. OBJECTIVE: We sought to investigate the relationship between a microvascular proliferative response and flow velocity in AVMs. METHODS: Resection specimens of 80 AVMs were clinically categorized as either high- or low-flow lesions, and histopathologically screened for the presence of microvessels, inflammation, thrombosis, or a combination of these. Immunohistochemistry was performed with endoglin (CD105), von Willebrand factor, and fibrinogen antibodies. RESULTS: Clinically, 37 AVMs were classified as high-flow lesions and 43 as low-flow lesions. In 81% of high-flow lesions microvascular proliferations were seen versus in 14% of low-flow lesions (P < .005). In high-flow lesions, which were embolized before surgery (30% of all), 88% showed microvascular proliferation, 88% inflammation, and 33% thrombosis. However, similar vasoproliferative responses were also observed in nonembolized AVM (69% high-flow and 14% low-flow lesions). Endoglin was more frequently expressed in high-flow lesions. Extracellular von Willebrand factor staining was found in most lesions, irrespective of flow type or presence of microvascular proliferations. LIMITATIONS: The study was carried out at a single tertiary referral center. CONCLUSIONS: Microvascular proliferative masses in AVMs appear to be strongly associated with high-flow characteristics. This could be explained to some extent by previous therapeutic embolization and/or inflammation in the lesion. However, occurrence of similar microvascular responses in AVM that were not embolized before surgery suggests that the biomechanical effects of high flow in these lesions may also have an angiogenic effect.
Assuntos
Malformações Arteriovenosas/patologia , Malformações Arteriovenosas/fisiopatologia , Embolização Terapêutica/efeitos adversos , Inflamação/complicações , Microvasos/patologia , Adolescente , Adulto , Idoso , Velocidade do Fluxo Sanguíneo , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto JovemRESUMO
BACKGROUND: The role of bone marrow-derived cells in stimulating angiogenesis, vascular repair or remodelling has been well established, but the nature of the circulating angiogenic cells is still controversial. DESIGN: The existing literature on different cell types that contribute to angiogenesis in multiple pathologies, most notably ischaemic and tumour angiogenesis, is reviewed, with a focus on subtypes of angiogenic mononuclear cells and their local recruitment and activation. RESULTS: A large number of different cells of myeloid origin support angiogenesis without incorporating permanently into the newly formed vessel, which distinguishes these circulating angiogenic cells (CAC) from endothelial progenitor cells (EPC). Although CAC frequently express individual endothelial markers, they all share multiple characteristics of monocytes and only express a limited set of discriminative surface markers in the circulation. When cultured ex vivo, or surrounding the angiogenic vessel in vivo, however, many of them acquire similar additional markers, making their discrimination in situ difficult. CONCLUSION: Different subsets of monocytes show angiogenic properties, but the distinct microenvironment, in vitro or in vivo, is needed for the development of their pro-angiogenic function.
Assuntos
Células Endoteliais/fisiologia , Monócitos/fisiologia , Neovascularização Patológica/fisiopatologia , Neovascularização Fisiológica/fisiologia , Células-Tronco/fisiologia , Humanos , Isquemia/fisiopatologiaRESUMO
Vascular endothelial cells contain unique storage organelles, designated Weibel-Palade bodies (WPBs), that deliver inflammatory and hemostatic mediators to the vascular lumen in response to agonists like thrombin and vasopressin. The main component of WPBs is von Willebrand factor (VWF), a multimeric glycoprotein crucial for platelet plug formation. In addition to VWF, several other components are known to be stored in WPBs, like osteoprotegerin, monocyte chemoattractant protein-1 and angiopoetin-2 (Ang-2). Here, we used an unbiased proteomics approach to identify additional residents of WPBs. Mass spectrometry analysis of purified WPBs revealed the presence of several known components such as VWF, Ang-2, and P-selectin. Thirty-five novel candidate WPB residents were identified that included insulin-like growth factor binding protein-7 (IGFBP7), which has been proposed to regulate angiogenesis. Immunocytochemistry revealed that IGFBP7 is a bona fide WPB component. Cotransfection studies showed that IGFBP7 trafficked to pseudo-WPB in HEK293 cells. Using a series of deletion variants of VWF, we showed that targeting of IGFBP7 to pseudo-WPBs was dependent on the carboxy-terminal D4-C1-C2-C3-CK domains of VWF. IGFBP7 remained attached to ultralarge VWF strings released upon exocytosis of WPBs under flow. The presence of IGFBP7 in WPBs highlights the role of this subcellular compartment in regulation of angiogenesis.
Assuntos
Células Endoteliais/química , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina/química , Proteômica/métodos , Corpos de Weibel-Palade/química , Células Endoteliais/fisiologia , Exocitose , Vetores Genéticos , Células HEK293 , Células Endoteliais da Veia Umbilical Humana , Humanos , Imuno-Histoquímica , Espectrometria de Massas , Neovascularização Fisiológica , Selectina-P/química , Estrutura Terciária de Proteína , Transporte Proteico , Transfecção , Corpos de Weibel-Palade/fisiologia , Fator de von Willebrand/químicaRESUMO
RATIONALE: Aging represents a major risk factor for coronary artery disease and aortic aneurysm formation. MicroRNAs (miRs) have emerged as key regulators of biological processes, but their role in age-associated vascular pathologies is unknown. OBJECTIVE: We aim to identify miRs in the vasculature that are regulated by age and play a role in age-induced vascular pathologies. METHODS AND RESULTS: Expression profiling of aortic tissue of young versus old mice identified several age-associated miRs. Among the significantly regulated miRs, the increased expression of miR-29 family members was associated with a profound downregulation of numerous extracellular matrix (ECM) components in aortas of aged mice, suggesting that this miR family contributes to ECM loss, thereby sensitizing the aorta for aneurysm formation. Indeed, miR-29 expression was significantly induced in 2 experimental models for aortic dilation: angiotensin II-treated aged mice and genetically induced aneurysms in Fibulin-4(R/R) mice. More importantly, miR-29b levels were profoundly increased in biopsies of human thoracic aneurysms, obtained from patients with either bicuspid (n=79) or tricuspid aortic valves (n=30). Finally, LNA-modified antisense oligonucleotide-mediated silencing of miR-29 induced ECM expression and inhibited angiotensin II-induced dilation of the aorta in mice. CONCLUSION: In conclusion, miR-29-mediated downregulation of ECM proteins may sensitize the aorta to the formation of aneurysms in advanced age. Inhibition of miR-29 in vivo abrogates aortic dilation in mice, suggesting that miR-29 may represent a novel molecular target to augment matrix synthesis and maintain vascular wall structural integrity.