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Sodium-glucose cotransporter-2 (SGLT-2) is expressed in the kidney and may contribute to anaemia and cardiovascular diseases. The effect of SGLT-2 inhibition on anaemia and vascular endpoints in sickle cell disease (SCD) is unknown. A murine model of SCD was studied to determine the effects of the SGLT-2 inhibitor, empagliflozin, on anaemia and stroke size. The University of Michigan's Precision Health Database was used to evaluate the effect of SGLT-2 inhibitors on anaemia in humans with SCD. SCD mice treated with daily empagliflozin for 8 weeks demonstrated increases in haemoglobin, haematocrit, erythrocyte counts, reticulocyte percentage and erythropoietin compared to vehicle-treated mice. Following photochemical-induced thrombosis of the middle cerebral artery, mice treated with empagliflozin demonstrated reduced stroke size compared to vehicle treated mice. In the electronic health records analysis, haemoglobin, haematocrit and erythrocyte counts increased in human SCD subjects treated with an SGLT-2 inhibitor. SGLT-2 inhibitor treatment of humans and mice with SCD is associated with improvement in anaemic parameters. Empagliflozin treatment is also associated with reduced stroke size in SCD mice suggesting SGLT-2 inhibitor treatment may be beneficial with regard to both anaemia and vascular complications in SCD patients.
Assuntos
Anemia Falciforme , Anemia , Compostos Benzidrílicos , Modelos Animais de Doenças , Glucosídeos , Inibidores do Transportador 2 de Sódio-Glicose , Acidente Vascular Cerebral , Animais , Anemia Falciforme/complicações , Anemia Falciforme/tratamento farmacológico , Anemia Falciforme/sangue , Anemia Falciforme/patologia , Inibidores do Transportador 2 de Sódio-Glicose/farmacologia , Humanos , Camundongos , Compostos Benzidrílicos/farmacologia , Glucosídeos/farmacologia , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/patologia , Masculino , Anemia/tratamento farmacológico , Anemia/etiologia , Feminino , Transportador 2 de Glucose-Sódio/metabolismo , Camundongos Endogâmicos C57BLRESUMO
Sickle cell disease is a prevalent hematologic condition, but some of the factors that lead to erythrocyte sickling are not fully known. A 58-year-old male patient with a history of sickle cell disease (SCD) and paroxysmal atrial fibrillation was transferred from an outside hospital for further management of refractory sickle cell crisis with acute chest syndrome. Before transfer, the patient received antibiotics and multiple packed red blood cell (pRBC) transfusions, with minimal effect on symptoms or anemia. After transfer, the patient developed rapid supraventricular tachycardia and atrial fibrillation (rates >160) with a drop in blood pressure. He was started on IV amiodarone. His heart rate was subsequently better controlled and converted to sinus rhythm the following day. Three days following initiation of amiodarone, the patient, with a hemoglobin count of 6.4 g/dl, required one additional unit of pRBC. On the fourth day, the patient's hemoglobin count rose to 9.4 g/dl, and he reported a marked improvement in symptoms. The improvements in symptoms and hemoglobin count were sustained, and the patient was discharged two days later. This remarkable improvement in anemia and symptoms triggered a search for potential causes. Amiodarone is a complex drug shown to have effects on multiple cell types, including erythrocytes. A recent preclinical study demonstrated reduced sickling and improved anemia in a murine model of SCD. This case report raises the possibility that amiodarone may have contributed to the rapid improvement in anemia and should be further explored in clinical trials. LEARNING POINTS: Prior studies support a link between erythrocyte sickling and membrane lipid composition.Amiodarone may impact erythrocyte pathophysiology by increasing cellular lipids including bis(mono)acylglycerol phosphate (BMP).Drugs with effects on erythrocyte lipid fractions may be beneficial during sickle cell crises.
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Traumatic brain injury (TBI) is associated with cardiovascular mortality in humans. Enhanced sympathetic activity following TBI may contribute to accelerated atherosclerosis. The effect of beta1-adrenergic receptor blockade on atherosclerosis progression induced by TBI was studied in apolipoprotein E deficient mice. Mice were treated with metoprolol or vehicle following TBI or sham operation. Mice treated with metoprolol experienced a reduced heart rate with no difference in blood pressure. Six weeks following TBI, mice were sacrificed for analysis of atherosclerosis. Total surface area and lesion thickness, analyzed at the level of the aortic valve, was found to be increased in mice receiving TBI with vehicle treatment but this effect was ameliorated in TBI mice receiving metoprolol. No effect of metoprolol on atherosclerosis was observed in mice receiving only sham operation. In conclusion, accelerated atherosclerosis following TBI is reduced with beta-adrenergic receptor antagonism. Beta blockers may be useful to reduce vascular risk associated with TBI.
Assuntos
Aterosclerose , Lesões Encefálicas Traumáticas , Animais , Camundongos , Antagonistas Adrenérgicos beta/farmacologia , Antagonistas Adrenérgicos beta/uso terapêutico , Aterosclerose/patologia , Pressão Sanguínea , Lesões Encefálicas Traumáticas/complicações , Lesões Encefálicas Traumáticas/tratamento farmacológico , Modelos Animais de Doenças , Metoprolol/farmacologia , Metoprolol/uso terapêutico , Camundongos Endogâmicos C57BLRESUMO
Sickle cell disease (SCD) is associated with altered plasma and erythrocyte lipid profiles. In a previous study, SCD mice with deficiency of proprotein convertase subtilisin/kexin type 9 (PCSK9) were observed to have more severe anemia and increased sickling compared to control SCD mice. Although PCSK9 affects circulating low density lipoprotein (LDL) by regulation of the LDL receptor, the effect of PCSK9 on anemia was independent of LDL receptor expression. In the current study, erythrocyte metabolomics were performed and revealed altered erythrocyte lipid species between SCD mice with and without PCSK9. Of particular interest, the late endosome-specific lipid bis(mono)acylglycerol phosphate (BMP) 44:12 was markedly decreased in erythrocytes from SCD mice deficient in PCSK9 mice relative to control SCD mice. Incubation of sickle erythrocytes with a neutralizing antibody to BMP increased erythrocyte sickling in vitro. In vitro treatment of SCD erythrocytes with amiodarone (1.5 µM) or medroxyprogesterone (6.75 µM), two pharmacologic compounds known to increase BMP, resulted in reduced erythrocyte sickling. Treatment of SCD mice with amiodarone (10 mg/kg) for 2 weeks resulted in increased BMP, improvement in anemia with reduced reticulocytosis, and decreased ex vivo sickling. In conclusion, severity of anemia in SCD is improved with amiodarone treatment, an effect which may be mediated through increased erythrocyte BMP.
Assuntos
Amiodarona , Anemia Falciforme , Amiodarona/farmacologia , Anemia Falciforme/complicações , Anemia Falciforme/tratamento farmacológico , Animais , Anticorpos Neutralizantes/farmacologia , Modelos Animais de Doenças , Eritrócitos/metabolismo , Lipoproteínas LDL/metabolismo , Medroxiprogesterona/farmacologia , Camundongos , Monoglicerídeos/metabolismo , Fosfatos/metabolismo , Pró-Proteína Convertase 9/metabolismo , Receptores de LDL/metabolismo , Subtilisinas/metabolismoRESUMO
Krüppel-like factors (KLFs) play essential roles in multiple biological functions, including maintaining vascular homeostasis. KLF11, a causative gene for maturity-onset diabetes of the young type 7, inhibits endothelial activation and protects against stroke. However, the role of KLF11 in venous thrombosis remains to be explored. Utilizing stasis-induced murine deep vein thrombosis (DVT) model and cultured endothelial cells (ECs), we identified an increase of KLF11 expression under prothrombotic conditions both in vivo and in vitro. The expression change of thrombosis-related genes was determined by utilizing gain- and loss-of-function approaches to alter KLF11 expression in ECs. Among these genes, KLF11 significantly downregulated tumor necrosis factor-α (TNF-α)-induced tissue factor (TF) gene transcription. Using reporter gene assay, chromatin immunoprecipitation assay, and co-immunoprecipitation, we revealed that KLF11 could reduce TNF-α-induced binding of early growth response 1 (EGR1) to TF gene promoter in ECs. In addition, we demonstrated that conventional Klf11 knockout mice were more susceptible to developing stasis-induced DVT. These results suggest that under prothrombotic conditions, KLF11 downregulates TF gene transcription via inhibition of EGR1 in ECs. In conclusion, KLF11 protects against venous thrombosis, constituting a potential molecular target for treating thrombosis.
Assuntos
Proteínas Reguladoras de Apoptose , Proteínas Repressoras , Trombose , Trombose Venosa , Animais , Proteínas Reguladoras de Apoptose/genética , Células Endoteliais/metabolismo , Humanos , Camundongos , Camundongos Knockout , Proteínas Repressoras/genética , Tromboplastina/genética , Fatores de Transcrição/genética , Fator de Necrose Tumoral alfa , Trombose Venosa/genética , Trombose Venosa/prevenção & controleRESUMO
Sickle cell disease (SCD) is associated with haemolytic anaemia and secondary activation of leucocytes and platelets, which in turn may further exacerbate haemolysis. As cytokine signalling pathways may participate in this cycle, the present study investigated whether pharmacological blockade of the interleukin-1 receptor (IL-1R) would mitigate anaemia in a murine model of SCD. Within 2 weeks of treatment, reduced markers of haemolysis were observed in anakinra-treated mice compared to vehicle-treated mice. After 4 weeks of anakinra treatment, mice showed increased numbers of erythrocytes, haemoglobin, and haematocrit, along with reduced reticulocytes. Blood from anakinra-treated mice was less susceptible to ex vivo erythrocyte sickling and was resistant to exogenous IL-1ß-mediated sickling. Supernatant generated from IL-1ß-treated platelets was sufficient to promote erythrocyte sickling, an effect not observed with platelet supernatant generated from IL-1R-/- mice. The sickling effect of IL-1ß-treated platelet supernatant was inhibited by a transforming growth factor-ß (TGF-ß) neutralising antibody, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibition, and superoxide scavengers, but replicated by recombinant TGF-ß. In conclusion, pharmacological IL-1R antagonism leads to improved anaemia in a murine SCD model. IL-1ß stimulation of platelets promotes erythrocyte sickling. This effect may be mediated by platelet-derived TGF-ß-induced reactive oxygen species generation though erythrocyte NADPH oxidase.
Assuntos
Anemia Falciforme/genética , Anemia/fisiopatologia , Plaquetas/metabolismo , Receptores de Interleucina-1/genética , Animais , Modelos Animais de Doenças , Eritrócitos Anormais , Humanos , CamundongosRESUMO
Sickle cell disease (SCD) is associated with chronic hemolytic anemia and a heightened inflammatory state. The causal role of inflammatory pathways in stroke associated with SCD is unclear. Therefore, the hypothesis that deletion of the non-hematopoietic interleukin-1 receptor (IL-1R) pool may be beneficial in SCD was pursued. Since potential deleterious effects of IL-1R signaling in SCD could be mediated via downstream production of interleukin-6 (IL-6), the role of the non-hematopoietic IL-6 pool was also addressed. Bone marrow transplantation (BMT) from SCD to wild-type (WT) recipient mice was used to generate SCD mice (Wt,SCDbmt). To generate mice with non-hematopoietic deficiency of IL-1R or IL-6, SCD marrow was transplanted into IL-1R deficient (IL1R-/-,SCDbmt) or IL-6 deficient recipients (IL6-/-,SCDbmt). Blood counts, reticulocytes, soluble E-selectin (Esel), and IL-6 levels were analyzed 14-15 weeks post-BMT. Ischemic stroke was induced by middle cerebral artery (MCA) photothrombosis at 16 weeks post-BMT. A separate group of Wt,SCDbmt mice was given the IL-1R inhibitor, anakinra, following stroke induction. Seventy-two hours after MCA occlusion, stroke volume was assessed by staining brain sections with 2,3,5-triphenyltetrazolium chloride. Formalin-fixed brain sections were also stained for macrophages with MAC3, for endothelial activation with ICAM-1, and for loss of blood brain barrier (BBB) integrity with fibrin(ogen) staining. All SCD mice generated by BMT were anemic and the severity of anemia was not different between Wt,SCDbmt, IL1R-/-,SCDbmt, and IL6-/-,SCDbmt mice. Three days following MCA occlusion, stroke volume was significantly reduced in IL1R-/-,SCDbmt mice compared to Wt,SCDbmt mice and IL6-/-,SCDbmt mice. Plasma levels of sE-sel were lower in IL1R-/-,SCDbmt compared to Wt,SCDbmt and IL-6-/-,SCDbmt mice. Post-stroke treatment of Wt,SCDbmt mice with anakinra decreased stroke size, leukocyte infiltration, ICAM-1 expression, and fibrin(ogen) accumulation compared to vehicle-treated mice. Deficiency of non-hematopoietic IL-1R or treatment with an IL-1R antagonist is sufficient to confer protection against the increased stroke size associated with SCD. These effects of IL1R deficiency are associated with reduced endothelial activation, leukocyte infiltration, and blood brain barrier disruption, and are independent of non-hematopoietic IL-6 signaling.
Assuntos
Anemia Falciforme , Receptores de Interleucina-1 , Anemia Falciforme/complicações , Anemia Falciforme/tratamento farmacológico , Anemia Falciforme/genética , Animais , Modelos Animais de Doenças , Proteína Antagonista do Receptor de Interleucina 1 , Camundongos , Camundongos Endogâmicos C57BL , Camundongos KnockoutRESUMO
We, the Editors of the Journal of the American Heart Association, sincerely regret the publication of the article "Diversity, Inclusion, and Equity: Evolution of Race and Ethnicity Considerations for the Cardiology Workforce in the United States of America From 1969 to 2019".1 We are aware that the publication of this flawed and biased article has caused a great deal of unnecessary pain and anguish to a number of parties, and reflects extremely poorly on us. We fully support the retraction of this article.
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OBJECTIVE: Clopidogrel is a commonly used P2Y12 inhibitor to treat and prevent arterial thrombotic events. Clopidogrel is a prodrug that requires bioactivation by CYP (cytochrome P450) enzymes to exert antiplatelet activity. Diabetes mellitus is associated with an increased risk of ischemic events, and impaired ability to generate the active metabolite (AM) from clopidogrel. The objective of this study is to identify the mechanism of clopidogrel resistance in a murine model of diet-induced obesity (DIO). Approach and Results: C57BL/6J mice and IL-1R-/- mice were given high-fat diet for 10 weeks to generate a murine model of diet-induced obesity. Platelet aggregation and carotid arterial thrombosis were assessed in response to clopidogrel treatment. Wild-type DIO mice exhibited resistance to antiplatelet and antithrombotic effects of clopidogrel that was associated with reduced hepatic expression of CYP genes and reduced generation of the AM. IL (Interleukin)-1 receptor-deficient DIO (IL1R-/- DIO) mice showed no resistance to clopidogrel. Lack of resistance was accompanied by increased exposure of the clopidogrel AM. This resistance was also absent when wild-type DIO mice were treated with the conjugate of the clopidogrel AM, DT-678. CONCLUSIONS: These findings indicate that antiplatelet effects of clopidogrel may be impaired in the setting of diabetes mellitus due to reduced prodrug bioactivation related to IL-1 receptor signaling. Therapeutic targeting of P2Y12 in patients with diabetes mellitus using the conjugate of clopidogrel AM may lead to improved outcomes.
Assuntos
Clopidogrel/farmacocinética , Clopidogrel/uso terapêutico , Resistência a Medicamentos , Obesidade/complicações , Receptores de Interleucina-1/fisiologia , Animais , Trombose das Artérias Carótidas/prevenção & controle , Clopidogrel/farmacologia , Sistema Enzimático do Citocromo P-450/genética , Diabetes Mellitus , Dieta Hiperlipídica , Modelos Animais de Doenças , Fibrinolíticos , Expressão Gênica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microssomos Hepáticos/enzimologia , Obesidade/etiologia , Obesidade/metabolismo , Agregação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária , Pró-Fármacos/farmacocinética , Pró-Fármacos/uso terapêutico , Receptores de Interleucina-1/deficiênciaRESUMO
Aging is characterized by increased aortic stiffness, an early, independent predictor and cause of cardiovascular disease. Oxidative stress from excess reactive oxygen species (ROS) production increases with age. Mitochondria and NADPH oxidases (NOXs) are two major sources of ROS in cardiovascular system. We showed previously that increased mitochondrial ROS levels over a lifetime induce aortic stiffening in a mouse oxidative stress model. Also, NADPH oxidase 4 (NOX4) expression and ROS levels increase with age in aortas, aortic vascular smooth muscle cells (VSMCs) and mitochondria, and are correlated with age-associated aortic stiffness in hypercholesterolemic mice. The present study investigated whether young mice (4 months-old) with increased mitochondrial NOX4 levels recapitulate vascular aging and age-associated aortic stiffness. We generated transgenic mice with low (Nox4TG605; 2.1-fold higher) and high (Nox4TG618; 4.9-fold higher) mitochondrial NOX4 expression. Young Nox4TG618 mice showed significant increase in aortic stiffness and decrease in phenylephrine-induced aortic contraction, but not Nox4TG605 mice. Increased mitochondrial oxidative stress increased intrinsic VSMC stiffness, induced aortic extracellular matrix remodeling and fibrosis, a leftward shift in stress-strain curves, decreased volume compliance and focal adhesion turnover in Nox4TG618 mice. Nox4TG618 VSMCs phenocopied other features of vascular aging such as increased DNA damage, increased premature and replicative senescence and apoptosis, increased proinflammatory protein expression and decreased respiration. Aortic stiffening in young Nox4TG618 mice was significantly blunted with mitochondrial-targeted catalase overexpression. This demonstration of the role of mitochondrial oxidative stress in aortic stiffness will galvanize search for new mitochondrial-targeted therapeutics for treatment of age-associated vascular dysfunction.
Assuntos
Aorta/metabolismo , Genes Mitocondriais , NADPH Oxidase 4/genética , Rigidez Vascular/genética , Fatores Etários , Animais , Aorta/fisiopatologia , Senescência Celular/genética , Matriz Extracelular/metabolismo , Expressão Gênica , Estudos de Associação Genética , Peróxido de Hidrogênio/metabolismo , Imuno-Histoquímica , Camundongos , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , NADPH Oxidase 4/metabolismo , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Superóxidos/metabolismo , Vasculite/genética , Vasculite/metabolismo , Vasculite/patologiaRESUMO
Objective- Mutations in Krüppel like factor-11 ( KLF11), a gene also known as maturity-onset diabetes mellitus of the young type 7, contribute to the development of diabetes mellitus. KLF11 has anti-inflammatory effects in endothelial cells and beneficial effects on stroke. However, the function of KLF11 in the cardiovascular system is not fully unraveled. In this study, we investigated the role of KLF11 in vascular smooth muscle cell biology and arterial thrombosis. Approach and Results- Using a ferric chloride-induced thrombosis model, we found that the occlusion time was significantly reduced in conventional Klf11 knockout mice, whereas bone marrow transplantation could not rescue this phenotype, suggesting that vascular KLF11 is critical for inhibition of arterial thrombosis. We further demonstrated that vascular smooth muscle cell-specific Klf11 knockout mice also exhibited significantly reduced occlusion time. The expression of tissue factor (encoded by the F3 gene), a main initiator of the coagulation cascade, was increased in the artery of Klf11 knockout mice, as determined by real-time quantitative polymerase chain reaction and immunofluorescence. Furthermore, vascular smooth muscle cells isolated from Klf11 knockout mouse aortas showed increased tissue factor expression, which was rescued by KLF11 overexpression. In human aortic smooth muscle cells, small interfering RNA-mediated knockdown of KLF11 increased tissue factor expression. Consistent results were observed on adenovirus-mediated overexpression of KLF11. Mechanistically, KLF11 downregulates F3 at the transcriptional level as determined by reporter and chromatin immunoprecipitation assays. Conclusions- Our data demonstrate that KLF11 is a novel transcriptional suppressor of F3 in vascular smooth muscle cells, constituting a potential molecular target for inhibition of arterial thrombosis.
Assuntos
Proteínas Reguladoras de Apoptose/fisiologia , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Proteínas Repressoras/fisiologia , Tromboplastina/biossíntese , Trombose/prevenção & controle , Animais , Antitrombina III/análise , Proteínas Reguladoras de Apoptose/antagonistas & inibidores , Proteínas Reguladoras de Apoptose/deficiência , Proteínas Reguladoras de Apoptose/genética , Transplante de Medula Óssea , Células Cultivadas , Cloretos/toxicidade , Imunoprecipitação da Cromatina , Regulação para Baixo , Feminino , Compostos Férricos/toxicidade , Regulação da Expressão Gênica , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Peptídeo Hidrolases/análise , Agregação Plaquetária , Interferência de RNA , Proteínas Recombinantes/metabolismo , Proteínas Repressoras/antagonistas & inibidores , Proteínas Repressoras/deficiência , Proteínas Repressoras/genética , Tromboplastina/genética , Trombose/induzido quimicamente , Transcrição GênicaRESUMO
Traumatic brain injury (TBI) has been associated with atherosclerosis and cardiovascular mortality in humans. However the causal relationship between TBI and vascular disease is unclear. This study investigated the direct role of TBI on vascular disease using a murine model of atherosclerosis. Apolipoprotein E deficient mice were placed on a western diet beginning at 10 weeks of age. Induction of TBI or a sham operation was performed at 14 weeks of age and mice were sacrificed 6 weeks later at 20 weeks of age. MRI revealed evidence of uniform brain injury in all mice subjected to TBI. There were no differences in total cholesterol levels or blood pressure between the groups. Complete blood counts and flow cytometry analysis performed on peripheral blood 6 weeks following TBI revealed a higher percentage of Ly6C-high monocytes in mice subjected to TBI compared to sham-treated mice. Mice with TBI also showed elevated levels of plasma soluble E-selectin and bone marrow tyrosine hydroxylase. Analysis of atherosclerosis at the time of sacrifice revealed increased atherosclerosis with increased Ly6C/G immunostaining in TBI mice compared to sham-treated mice. In conclusion, progression of atherosclerosis is accelerated following TBI. Targeting inflammatory pathways in patients with TBI may reduce subsequent vascular complications.
Assuntos
Apolipoproteínas E/deficiência , Aterosclerose/etiologia , Aterosclerose/patologia , Lesões Encefálicas Traumáticas/fisiopatologia , Animais , Determinação da Pressão Arterial , Modelos Animais de Doenças , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos KnockoutRESUMO
Endothelial dysfunction precedes atherosclerosis and may constitute a critical link between obesity-related inflammation and cardiovascular disease. Neutrophil extracellular traps (NETs) have been shown to promote vascular damage in murine models of autoimmune disease and atherosclerosis. The impact of NETs towards endothelial dysfunction associated with obesity is unknown. Using a diet-induced obesity (DIO) mouse model, this study investigated whether the inhibition or degradation of NETs could reduce the endothelial dysfunction observed in DIO mice. Following induction of DIO, there were elevated plasma concentrations of monocyte chemoattractant protein-1 (MCP-1) and impairment of mesenteric arteriolar vasorelaxation in response to acetylcholine as measured by pressure myography. A marker of NET formation, cathelicidin-related antimicrobial peptide (CRAMP), was markedly increased in mesenteric arterial walls of DIO mice compared to mice on standard chow. Prevention of NET formation with Cl-amidine or dissolution of NETs with DNase restored endothelium-dependent vasodilation to the mesenteric arteries of DIO mice. These findings suggest an instrumental role for NETs in obesity-induced endothelial dysfunction.
Assuntos
Endotélio Vascular/metabolismo , Armadilhas Extracelulares/metabolismo , Animais , Peptídeos Catiônicos Antimicrobianos/análise , Peptídeos Catiônicos Antimicrobianos/sangue , Doenças Cardiovasculares/fisiopatologia , Quimiocina CCL2/análise , Quimiocina CCL2/sangue , Dieta Hiperlipídica , Modelos Animais de Doenças , Armadilhas Extracelulares/fisiologia , Inflamação/metabolismo , Masculino , Artérias Mesentéricas/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Obesidade/fisiopatologia , Doenças Vasculares/fisiopatologia , Vasodilatação , CatelicidinasRESUMO
Identification of inflammatory mediators that regulate the vascular response to vasopressor molecules may aid in the development of novel therapeutic agents to treat or prevent hypertensive vascular diseases. Leukocytes have recently been shown to be capable of modifying blood pressure responses to vasopressor molecules. The purpose of this study was to test the hypothesis that deficiency of the leukocyte ligand, Psgl-1, would reduce the pressor response to angiotensin II (Ang II). Mice deficient in Psgl-1 (Psgl-1-/-) along with wild-type (WT) controls were treated for 2 weeks with a continuous infusion of Ang II. No differences in blood pressure between the groups were noted at baseline, however after 5 days of Ang II infusion, systolic blood pressures were higher in WT compared to Psgl-1-/- mice. The pressor response to acute administration of high dose Ang II was also attenuated in Psgl-1-/- compared to WT mice. Chimeric mice with hematopoietic deficiency of Psgl-1 similarly showed a reduced pressor response to Ang II. This effect was associated with reduced plasma interleukin-17 (IL-17) levels in Psgl-1-/- mice and the reduced pressor response was restored by administration of recombinant IL-17. In conclusion, hematopoietic deficiency of Psgl-1 attenuates Ang II-induced hypertension, an effect that may be mediated by reduced IL-17.
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Angiotensina II/metabolismo , Hipertensão/fisiopatologia , Glicoproteínas de Membrana/metabolismo , Vasoconstritores/metabolismo , Angiotensina II/administração & dosagem , Animais , Pressão Sanguínea/efeitos dos fármacos , Modelos Animais de Doenças , Interleucina-17/metabolismo , Glicoproteínas de Membrana/deficiência , Camundongos , Camundongos KnockoutRESUMO
The effect of lipid lowering on the incidence of deep venous thrombosis (DVT) is controversial. The purpose of this study was to determine the effect of proprotein convertase subtilisin/kexin type 9 (PCSK9) deficiency on development of DVT in mice. Pcsk9 deficient (pcsk9 -/-) and wild-type (WT) littermates underwent partial inferior vena cava (IVC) ligation to induce venous thrombosis. 48 hours following IVC ligation, IVC thrombosis was evident in 60% of WT mice and 25% of pcsk9 -/- mice (p < 0.05). Analysis of IVC thrombosis revealed greater thrombus weight, length, myeloid cell recruitment, and more neutrophil extracellular trap formation (NETs) in WT compared to pcsk9 -/- mice. Intravital microscopy performed two hours following partial IVC ligation revealed that leukocyte firm attachment was increased in WT mice compared to mice undergoing a sham operation, however leukocyte attachment was reduced in pcsk9 -/- mice compared to WT mice. In conclusion, deficiency of PCSK9 is associated with protection from venous thrombosis. This protection is associated with reduced leukocyte recruitment and NET formation at the site of thrombosis.
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Pró-Proteína Convertase 9/fisiologia , Trombose Venosa/prevenção & controle , Animais , HDL-Colesterol/sangue , HDL-Colesterol/efeitos dos fármacos , LDL-Colesterol/sangue , LDL-Colesterol/efeitos dos fármacos , Metabolismo dos Lipídeos/fisiologia , Lipídeos/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pró-Proteína Convertase 9/deficiência , Pró-Proteína Convertase 9/metabolismo , Pró-Proteína Convertases , Serina Endopeptidases , Subtilisinas , Trombose Venosa/metabolismoRESUMO
Antiphospholipid antibodies, present in one-third of lupus patients, increase the risk of thrombosis. We recently reported a key role for neutrophils - neutrophil extracellular traps (NETs), in particular - in the thrombotic events that define antiphospholipid syndrome (APS). To further elucidate the role of neutrophils in APS, we performed a comprehensive transcriptome analysis of neutrophils isolated from patients with primary APS. Moreover, APS-associated venous thrombosis was modeled by treating mice with IgG prepared from APS patients, followed by partial restriction of blood flow through the inferior vena cava. In patients, APS neutrophils demonstrated a proinflammatory signature with overexpression of genes relevant to IFN signaling, cellular defense, and intercellular adhesion. For in vivo studies, we focused on P-selectin glycoprotein ligand-1 (PSGL-1), a key adhesion molecule overexpressed in APS neutrophils. The introduction of APS IgG (as compared with control IgG) markedly potentiated thrombosis in WT mice, but not PSGL-1-KOs. PSGL-1 deficiency was also associated with reduced leukocyte vessel wall adhesion and NET formation. The thrombosis phenotype was restored in PSGL-1-deficient mice by infusion of WT neutrophils, while an anti-PSGL-1 monoclonal antibody inhibited APS IgG-mediated thrombosis in WT mice. PSGL-1 represents a potential therapeutic target in APS.
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Síndrome Antifosfolipídica/imunologia , Armadilhas Extracelulares/imunologia , Neutrófilos/imunologia , Animais , Anticorpos Antifosfolipídeos/imunologia , Síndrome Antifosfolipídica/genética , Humanos , Imunoglobulina G/administração & dosagem , Imunoglobulina G/imunologia , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/imunologia , Camundongos , Camundongos Knockout , Transcriptoma , Regulação para CimaRESUMO
BACKGROUND: The MMP (matrix metalloproteinase) family plays diverse and critical roles in directing vascular wall remodeling in atherosclerosis. Unlike secreted-type MMPs, a member of the membrane-type MMP family, MT1-MMP (membrane-type 1 MMP; MMP14), mediates pericellular extracellular matrix degradation that is indispensable for maintaining physiological extracellular matrix homeostasis. However, given the premature mortality exhibited by MT1-MMP-null mice, the potential role of the proteinase in atherogenesis remains elusive. We sought to determine the effects of both MT1-MMP heterozygosity and tissue-specific gene targeting on atherogenesis in APOE (apolipoprotein E)-null mice. METHODS AND RESULTS: MT1-MMP heterozygosity in the APOE-null background (Mmp14+/-Apoe-/- ) significantly promoted atherogenesis relative to Mmp14+/+Apoe-/- mice. Furthermore, the tissue-specific deletion of MT1-MMP from vascular smooth muscle cells (VSMCs) in SM22α-Cre(+)Mmp14F/FApoe-/- (VSMC-knockout) mice likewise increased the severity of atherosclerotic lesions. Although VSMC-knockout mice also developed progressive atherosclerotic aneurysms in their iliac arteries, macrophage- and adipose-specific MT1-MMP-knockout mice did not display this sensitized phenotype. In VSMC-knockout mice, atherosclerotic lesions were populated by hyperproliferating VSMCs (smooth muscle actin- and Ki67-double-positive cells) that were characterized by a proinflammatory gene expression profile. Finally, MT1-MMP-null VSMCs cultured in a 3-dimensional spheroid model system designed to mimic in vivo-like cell-cell and cell-extracellular matrix interactions, likewise displayed markedly increased proliferative potential. CONCLUSIONS: MT1-MMP expressed by VSMCs plays a key role in limiting the progression of atherosclerosis in APOE-null mice by regulating proliferative responses and inhibiting the deterioration of VSMC function in atherogenic vascular walls.