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1.
Int J Mol Sci ; 22(16)2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34445337

RESUMO

In fibrotic diseases, myofibroblasts derive from a range of cell types including endothelial-to-mesenchymal transition (EndMT). Increasing evidence suggests that miRNAs are key regulators in biological processes but their profile is relatively understudied in EndMT. In human umbilical vein endothelial cells (HUVEC), EndMT was induced by treatment with TGFß2 and IL1ß. A significant decrease in endothelial markers such as VE-cadherin, CD31 and an increase in mesenchymal markers such as fibronectin were observed. In parallel, miRNA profiling showed that miR-126-3p was down-regulated in HUVECs undergoing EndMT and over-expression of miR-126-3p prevented EndMT, maintaining CD31 and repressing fibronectin expression. EndMT was investigated using lineage tracing with transgenic Cdh5-Cre-ERT2; Rosa26R-stop-YFP mice in two established models of fibrosis: cardiac ischaemic injury and kidney ureteric occlusion. In both cardiac and kidney fibrosis, lineage tracing showed a significant subpopulation of endothelial-derived cells expressed mesenchymal markers, indicating they had undergone EndMT. In addition, miR-126-3p was restricted to endothelial cells and down-regulated in murine fibrotic kidney and heart tissue. These findings were confirmed in patient kidney biopsies. MiR-126-3p expression is restricted to endothelial cells and is down-regulated during EndMT. Over-expression of miR-126-3p reduces EndMT, therefore, it could be considered for miRNA-based therapeutics in fibrotic organs.


Assuntos
Transdiferenciação Celular/genética , Rim/patologia , MicroRNAs/fisiologia , Miocárdio/patologia , Animais , Células Cultivadas , Células Endoteliais/patologia , Células Endoteliais/fisiologia , Fibrose/genética , Células Endoteliais da Veia Umbilical Humana/metabolismo , Células Endoteliais da Veia Umbilical Humana/patologia , Células Endoteliais da Veia Umbilical Humana/fisiologia , Humanos , Rim/metabolismo , Células-Tronco Mesenquimais/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Miocárdio/metabolismo , Miofibroblastos/metabolismo , Miofibroblastos/patologia
2.
FASEB J ; 35(5): e21604, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33913566

RESUMO

Myocardial infarction leads to a rapid innate immune response that is ultimately required for repair of damaged heart tissue. We therefore examined circulating monocyte dynamics immediately after reperfusion of the culprit coronary vessel in STEMI patients to determine whether this correlated with level of cardiac injury. A mouse model of cardiac ischemia/reperfusion injury was subsequently used to establish the degree of monocyte margination to the coronary vasculature that could potentially contribute to the drop in circulating monocytes. We retrospectively analyzed blood samples from 51 STEMI patients to assess the number of non-classical (NC), classical, and intermediate monocytes immediately following primary percutaneous coronary intervention. Classical and intermediate monocytes showed minimal change. On the other hand, circulating numbers of NC monocytes fell by approximately 50% at 90 minutes post-reperfusion. This rapid decrease in NC monocytes was greatest in patients with the largest infarct size (P < .05) and correlated inversely with left ventricular function (r = 0.41, P = .04). The early fall in NC monocytes post-reperfusion was confirmed in a second prospective study of 13 STEMI patients. Furthermore, in a mouse cardiac ischemia model, there was significant monocyte adhesion to coronary vessel endothelium at 2 hours post-reperfusion pointing to a specific and rapid vessel margination response to cardiac injury. In conclusion, rapid depletion of NC monocytes from the circulation in STEMI patients following coronary artery reperfusion correlates with the level of acute cardiac injury and involves rapid margination to the coronary vasculature.


Assuntos
Traumatismos Cardíacos/sangue , Traumatismos Cardíacos/patologia , Monócitos/patologia , Infarto do Miocárdio com Supradesnível do Segmento ST/complicações , Animais , Feminino , Traumatismos Cardíacos/etiologia , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Retrospectivos
4.
Genes (Basel) ; 12(2)2021 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-33513792

RESUMO

Hereditary haemorrhagic telangiectasia (HHT) is characterised by arteriovenous malformations (AVMs). These vascular abnormalities form when arteries and veins directly connect, bypassing the local capillary system. Large AVMs may occur in the lungs, liver and brain, increasing the risk of morbidity and mortality. Smaller AVMs, known as telangiectases, are prevalent on the skin and mucosal lining of the nose, mouth and gastrointestinal tract and are prone to haemorrhage. HHT is primarily associated with a reduction in endoglin (ENG) or ACVRL1 activity due to loss-of-function mutations. ENG and ACVRL1 transmembrane receptors are expressed on endothelial cells (ECs) and bind to circulating ligands BMP9 and BMP10 with high affinity. Ligand binding to the receptor complex leads to activation of the SMAD1/5/8 signalling pathway to regulate downstream gene expression. Various genetic animal models demonstrate that disruption of this pathway in ECs results in AVMs. The vascular abnormalities underlying AVM formation result from abnormal EC responses to angiogenic and haemodynamic cues, and include increased proliferation, reduced migration against the direction of blood flow and an increased EC footprint. There is growing evidence that targeting VEGF signalling has beneficial outcomes in HHT patients and in animal models of this disease. The anti-VEGF inhibitor bevacizumab reduces epistaxis and has a normalising effect on high cardiac output in HHT patients with hepatic AVMs. Blocking VEGF signalling also reduces vascular malformations in mouse models of HHT1 and HHT2. However, VEGF signalling is complex and drives numerous downstream pathways, and it is not yet clear which pathway (or combination of pathways) is critical to target. This review will consider the recent evidence gained from HHT clinical and preclinical studies that are increasing our understanding of HHT pathobiology and informing therapeutic strategies.


Assuntos
Predisposição Genética para Doença , Telangiectasia Hemorrágica Hereditária/tratamento farmacológico , Telangiectasia Hemorrágica Hereditária/genética , Alelos , Animais , Proteínas Morfogenéticas Ósseas/genética , Proteínas Morfogenéticas Ósseas/metabolismo , Gerenciamento Clínico , Células Endoteliais/metabolismo , Medicina Baseada em Evidências , Fator 2 de Diferenciação de Crescimento/genética , Fator 2 de Diferenciação de Crescimento/metabolismo , Humanos , Mutação , Fenótipo , Telangiectasia Hemorrágica Hereditária/diagnóstico , Telangiectasia Hemorrágica Hereditária/metabolismo
6.
Artigo em Inglês | MEDLINE | ID: mdl-32979174

RESUMO

Ageing is the biggest risk factor for impaired cardiovascular health, with cardiovascular disease being the leading cause of death in 40% of individuals over 65 years old. Ageing is associated with both an increased prevalence of cardiovascular disease including heart failure, coronary artery disease, and myocardial infarction. Furthermore, ageing is associated with a poorer prognosis to these diseases. Genetic models allowing the elimination of senescent cells revealed that an accumulation of senescence contributes to the pathophysiology of cardiovascular ageing and promotes the progression of cardiovascular disease through the expression of a proinflammatory and profibrotic senescence-associated secretory phenotype. These studies have resulted in an effort to identify pharmacological therapeutics that enable the specific elimination of senescent cells through apoptosis induction. These senescent cell apoptosis-inducing compounds are termed senolytics and their potential to ameliorate age-associated cardiovascular disease is the focus of this review.

7.
Aging Cell ; 19(10): e13249, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32996233

RESUMO

A key component of cardiac ischemia-reperfusion injury (IRI) is the increased generation of reactive oxygen species, leading to enhanced inflammation and tissue dysfunction in patients following intervention for myocardial infarction. In this study, we hypothesized that oxidative stress, due to ischemia-reperfusion, induces senescence which contributes to the pathophysiology of cardiac IRI. We demonstrate that IRI induces cellular senescence in both cardiomyocytes and interstitial cell populations and treatment with the senolytic drug navitoclax after ischemia-reperfusion improves left ventricular function, increases myocardial vascularization, and decreases scar size. SWATH-MS-based proteomics revealed that biological processes associated with fibrosis and inflammation that were increased following ischemia-reperfusion were attenuated upon senescent cell clearance. Furthermore, navitoclax treatment reduced the expression of pro-inflammatory, profibrotic, and anti-angiogenic cytokines, including interferon gamma-induced protein-10, TGF-ß3, interleukin-11, interleukin-16, and fractalkine. Our study provides proof-of-concept evidence that cellular senescence contributes to impaired heart function and adverse remodeling following cardiac ischemia-reperfusion. We also establish that post-IRI the SASP plays a considerable role in the inflammatory response. Subsequently, senolytic treatment, at a clinically feasible time-point, attenuates multiple components of this response and improves clinically important parameters. Thus, cellular senescence represents a potential novel therapeutic avenue to improve patient outcomes following cardiac ischemia-reperfusion.

9.
Circ Res ; 127(9): 1122-1137, 2020 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-32762495

RESUMO

RATIONALE: Hereditary hemorrhagic telangiectasia (HHT) is a genetic disease caused by mutations in ENG, ALK1, or SMAD4. Since proteins from all 3 HHT genes are components of signal transduction of TGF-ß (transforming growth factor ß) family members, it has been hypothesized that HHT is a disease caused by defects in the ENG-ALK1-SMAD4 linear signaling. However, in vivo evidence supporting this hypothesis is scarce. OBJECTIVE: We tested this hypothesis and investigated the therapeutic effects and potential risks of induced-ALK1 or -ENG overexpression (OE) for HHT. METHODS AND RESULTS: We generated a novel mouse allele (ROSA26Alk1) in which HA (human influenza hemagglutinin)-tagged ALK1 and bicistronic eGFP expression are induced by Cre activity. We examined whether ALK1-OE using the ROSA26Alk1 allele could suppress the development of arteriovenous malformations (AVMs) in wounded adult skin and developing retinas of Alk1- and Eng-inducible knockout (iKO) mice. We also used a similar approach to investigate whether ENG-OE could rescue AVMs. Biochemical and immunofluorescence analyses confirmed the Cre-dependent OE of the ALK1-HA transgene. We could not detect any pathological signs in ALK1-OE mice up to 3 months after induction. ALK1-OE prevented the development of retinal AVMs and wound-induced skin AVMs in Eng-iKO as well as Alk1-iKO mice. ALK1-OE normalized expression of SMAD and NOTCH target genes in ENG-deficient endothelial cells (ECs) and restored the effect of BMP9 (bone morphogenetic protein 9) on suppression of phosphor-AKT levels in these endothelial cells. On the other hand, ENG-OE could not inhibit the AVM development in Alk1-iKO models. CONCLUSIONS: These data support the notion that ENG and ALK1 form a linear signaling pathway for the formation of a proper arteriovenous network during angiogenesis. We suggest that ALK1 OE or activation can be an effective therapeutic strategy for HHT. Further research is required to study whether this therapy could be translated into treatment for humans.


Assuntos
Receptores de Activinas Tipo II/metabolismo , Malformações Arteriovenosas/prevenção & controle , Células Endoteliais/metabolismo , Telangiectasia Hemorrágica Hereditária/metabolismo , Receptores de Activinas Tipo II/deficiência , Receptores de Activinas Tipo II/genética , Alelos , Animais , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Malformações Arteriovenosas/genética , Modelos Animais de Doenças , Endoglina/deficiência , Endoglina/genética , Endoglina/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Fator 2 de Diferenciação de Crescimento/metabolismo , Camundongos , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , RNA não Traduzido , Receptores Notch/genética , Receptores Notch/metabolismo , Vasos Retinianos/anormalidades , Transdução de Sinais , Pele/irrigação sanguínea , Pele/lesões , Proteína Smad4/genética , Proteína Smad4/metabolismo , Telangiectasia Hemorrágica Hereditária/genética , Fator de Crescimento Transformador beta
10.
Angiogenesis ; 23(4): 559-566, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32506200

RESUMO

INTRODUCTION: Endoglin (ENG) forms a receptor complex with ALK1 in endothelial cells (ECs) to promote BMP9/10 signalling. Loss of function mutations in either ENG or ALK1 genes lead to the inherited vascular disorder hereditary haemorrhagic telangiectasia (HHT), characterised by arteriovenous malformations (AVMs). However, the vessel-specific role of ENG and ALK1 proteins in protecting against AVMs is unclear. For example, AVMs have been described to initiate in arterioles, whereas ENG is predominantly expressed in venous ECs. To investigate whether ENG has any arterial involvement in protecting against AVM formation, we specifically depleted the Eng gene in venous and capillary endothelium whilst maintaining arterial expression, and investigated how this affected the incidence and location of AVMs in comparison with pan-endothelial Eng knockdown. METHODS: Using the mouse neonatal retinal model of angiogenesis, we first established the earliest time point at which Apj-Cre-ERT2 activity was present in venous and capillary ECs but absent from arterial ECs. We then compared the incidence of AVMs following pan-endothelial or venous/capillary-specific ENG knockout. RESULTS: Activation of Apj-Cre-ERT2 with tamoxifen from postnatal day (P) 5 ensured preservation of arterial ENG protein expression. Specific loss of ENG expression in ECs of veins and capillaries led to retinal AVMs at a similar frequency to pan-endothelial loss of ENG. AVMs occurred in the proximal as well as the distal part of the retina consistent with a defect in vascular remodelling during maturation of the vasculature. CONCLUSION: Expression of ENG is not required in arterial ECs to protect against AVM formation.

11.
Circ Res ; 126(2): 243-257, 2020 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-31805812

RESUMO

RATIONALE: ENG (endoglin) is a coreceptor for BMP (bone morphogenetic protein) 9/10 and is strongly expressed in endothelial cells. Mutations in ENG lead to the inherited vascular disorder hereditary hemorrhagic telangiectasia characterized by local telangiectases and larger arteriovenous malformations (AVMs); but how ENG functions to regulate the adult vasculature is not understood. OBJECTIVE: The goal of the work was to determine how ENG maintains vessel caliber in adult life to prevent AVM formation and thereby protect heart function. METHODS AND RESULTS: Genetic depletion of endothelial Eng in adult mice led to a significant reduction in mean aortic blood pressure. There was no evidence of hemorrhage, anemia, or AVMs in major organs to explain the reduced aortic pressure. However, large AVMs developed in the peripheral vasculature intimately associated with the pelvic cartilaginous symphysis-a noncapsulated cartilage with a naturally high endogenous expression of VEGF (vascular endothelial growth factor). The increased blood flow through these peripheral AVMs explained the drop in aortic blood pressure and led to increased cardiac preload, and high stroke volumes, ultimately resulting in high-output heart failure. Development of pelvic AVMs in this region of high VEGF expression occurred because loss of ENG in endothelial cells leads to increased sensitivity to VEGF and a hyperproliferative response. Development of AVMs and associated progression to high-output heart failure in the absence of endothelial ENG was attenuated by targeting VEGF signaling with an anti-VEGFR2 (VEGF receptor 2) antibody. CONCLUSIONS: ENG promotes the normal balance of VEGF signaling in quiescent endothelial cells to maintain vessel caliber-an essential function in conditions of increased VEGF expression such as local hypoxia or inflammation. In the absence of endothelial ENG, increased sensitivity to VEGF drives abnormal endothelial proliferation in local regions of high VEGF expression, leading to AVM formation and a rapid injurious impact on heart function.


Assuntos
Malformações Arteriovenosas/metabolismo , Endoglina/genética , Endotélio Vascular/metabolismo , Insuficiência Cardíaca/etiologia , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Malformações Arteriovenosas/complicações , Malformações Arteriovenosas/genética , Malformações Arteriovenosas/patologia , Pressão Sanguínea , Proliferação de Células , Endoglina/metabolismo , Células Endoteliais/metabolismo , Células Endoteliais/fisiologia , Endotélio Vascular/patologia , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Transdução de Sinais , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo
12.
Proc Natl Acad Sci U S A ; 116(36): 17800-17808, 2019 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-31431534

RESUMO

Endoglin (ENG) is a coreceptor of the transforming growth factor-ß (TGFß) family signaling complex, which is highly expressed on endothelial cells and plays a key role in angiogenesis. Its extracellular domain can be cleaved and released into the circulation as soluble ENG (sENG). High circulating levels of sENG contribute to the pathogenesis of preeclampsia (PE). Circulating bone morphogenetic protein 9 (BMP9), a vascular quiescence and endothelial-protective factor, binds sENG with high affinity, but how sENG participates in BMP9 signaling complexes is not fully resolved. sENG was thought to be a ligand trap for BMP9, preventing type II receptor binding and BMP9 signaling. Here we show that, despite cell-surface ENG being a dimer linked by disulfide bonds, sENG purified from human placenta and plasma from PE patients is primarily in a monomeric form. Incubating monomeric sENG with the circulating form of BMP9 (prodomain-bound form) in solution leads to the release of the prodomain and formation of a sENG:BMP9 complex. Furthermore, we demonstrate that binding of sENG to BMP9 does not inhibit BMP9 signaling. Indeed, the sENG:BMP9 complex signals with comparable potency and specificity to BMP9 on human primary endothelial cells. The full signaling activity of the sENG:BMP9 complex required transmembrane ENG. This study confirms that rather than being an inhibitory ligand trap, increased circulating sENG might preferentially direct BMP9 signaling via cell-surface ENG at the endothelium. This is important for understanding the role of sENG in the pathobiology of PE and other cardiovascular diseases.


Assuntos
Endoglina/metabolismo , Fator 2 de Diferenciação de Crescimento/metabolismo , Placenta/metabolismo , Pré-Eclâmpsia/metabolismo , Proteínas da Gravidez/metabolismo , Transdução de Sinais , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Feminino , Humanos , Placenta/patologia , Pré-Eclâmpsia/patologia , Gravidez
13.
JCI Insight ; 52019 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-30835717

RESUMO

Sarcomeric disarray is a hallmark of gene mutations in patients with Hypertrophic Cardiomyopathy (HCM). However, it is unknown when detrimental sarcomeric changes first occur and whether they originate in the developing embryonic heart. Furthermore, Rho Kinase (ROCK) is a serine threonine protein kinase that is critical for regulating the function of several sarcomeric proteins and therefore, our aim was to determine if disruption of ROCK signalling during the earliest stages of heart development would disrupt the integrity of sarcomeres altering heart development and function. Using a mouse model in which the function of ROCK is specifically disrupted in embryonic cardiomyocytes we demonstrate a progressive cardiomyopathy that first appeared as sarcomeric disarray during cardiogenesis. This led to abnormalities in the structure of embryonic ventricular wall and compensatory cardiomyocyte hypertrophy during foetal development. This sarcomeric disruption and hypertrophy persisted throughout adult life, triggering left ventricular concentric hypertrophy with systolic dysfunction, and re-activation of foetal gene expression and cardiac fibrosis, all typical features of HCM. Taken together, our findings establish a novel mechanism for the developmental origin of the sarcomeric phenotype of HCM and suggest that variants in the ROCK genes or disruption of ROCK signalling could, in part, contribute to its pathogenesis.


Assuntos
Cardiomiopatia Hipertrófica/genética , Ventrículos do Coração/patologia , Sarcômeros/patologia , Quinases Associadas a rho/genética , Animais , Cardiomiopatia Hipertrófica/patologia , Modelos Animais de Doenças , Embrião de Mamíferos , Ventrículos do Coração/citologia , Ventrículos do Coração/embriologia , Humanos , Mutação com Perda de Função , Camundongos , Camundongos Transgênicos , Miócitos Cardíacos/citologia , Miócitos Cardíacos/patologia , Sarcômeros/metabolismo , Quinases Associadas a rho/metabolismo
14.
Aging Cell ; 18(3): e12945, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30920115

RESUMO

Cardiovascular disease is the leading cause of death in individuals over 60 years old. Aging is associated with an increased prevalence of coronary artery disease and a poorer prognosis following acute myocardial infarction (MI). With age, senescent cells accumulate in tissues, including the heart, and contribute to age-related pathologies. However, the role of senescence in recovery following MI has not been investigated. In this study, we demonstrate that treatment of aged mice with the senolytic drug, navitoclax, eliminates senescent cardiomyocytes and attenuates profibrotic protein expression in aged mice. Importantly, clearance of senescent cells improved myocardial remodelling and diastolic function as well as overall survival following MI. These data provide proof-of-concept evidence that senescent cells are major contributors to impaired function and increased mortality following MI and that senolytics are a potential new therapeutic avenue for MI.


Assuntos
Envelhecimento/efeitos dos fármacos , Compostos de Anilina/farmacologia , Antineoplásicos/farmacologia , Senescência Celular/efeitos dos fármacos , Infarto do Miocárdio/tratamento farmacológico , Sulfonamidas/farmacologia , Doença Aguda , Compostos de Anilina/administração & dosagem , Animais , Antineoplásicos/administração & dosagem , Sobrevivência Celular/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Infarto do Miocárdio/patologia , Sulfonamidas/administração & dosagem
15.
EMBO J ; 38(5)2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30737259

RESUMO

Ageing is the biggest risk factor for cardiovascular disease. Cellular senescence, a process driven in part by telomere shortening, has been implicated in age-related tissue dysfunction. Here, we address the question of how senescence is induced in rarely dividing/post-mitotic cardiomyocytes and investigate whether clearance of senescent cells attenuates age-related cardiac dysfunction. During ageing, human and murine cardiomyocytes acquire a senescent-like phenotype characterised by persistent DNA damage at telomere regions that can be driven by mitochondrial dysfunction and crucially can occur independently of cell division and telomere length. Length-independent telomere damage in cardiomyocytes activates the classical senescence-inducing pathways, p21CIP and p16INK4a, and results in a non-canonical senescence-associated secretory phenotype, which is pro-fibrotic and pro-hypertrophic. Pharmacological or genetic clearance of senescent cells in mice alleviates detrimental features of cardiac ageing, including myocardial hypertrophy and fibrosis. Our data describe a mechanism by which senescence can occur and contribute to age-related myocardial dysfunction and in the wider setting to ageing in post-mitotic tissues.


Assuntos
Cardiomegalia/patologia , Senescência Celular , Dano ao DNA , Fibrose/patologia , Mitose , Miócitos Cardíacos/patologia , Encurtamento do Telômero , Envelhecimento , Animais , Cardiomegalia/etiologia , Feminino , Fibrose/etiologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Monoaminoxidase/fisiologia , Miócitos Cardíacos/metabolismo , Fenótipo , RNA/fisiologia , Ratos Sprague-Dawley , Telomerase/fisiologia
16.
Circulation ; 138(23): 2698-2712, 2018 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-30571259

RESUMO

BACKGROUND: Hereditary Hemorrhagic Telangiectasia type 2 (HHT2) is an inherited genetic disorder characterized by vascular malformations and hemorrhage. HHT2 results from ACVRL1 haploinsufficiency, the remaining wild-type allele being unable to contribute sufficient protein to sustain endothelial cell function. Blood vessels function normally but are prone to respond to angiogenic stimuli, leading to the development of telangiectasic lesions that can bleed. How ACVRL1 haploinsufficiency leads to pathological angiogenesis is unknown. METHODS: We took advantage of Acvrl1+/- mutant mice that exhibit HHT2 vascular lesions and focused on the neonatal retina and the airway system after Mycoplasma pulmonis infection, as physiological and pathological models of angiogenesis, respectively. We elucidated underlying disease mechanisms in vitro by generating Acvrl1+/- mouse embryonic stem cell lines that underwent sprouting angiogenesis and performed genetic complementation experiments. Finally, HHT2 plasma samples and skin biopsies were analyzed to determine whether the mechanisms evident in mice are conserved in humans. RESULTS: Acvrl1+/- retinas at postnatal day 7 showed excessive angiogenesis and numerous endothelial "tip cells" at the vascular front that displayed migratory defects. Vascular endothelial growth factor receptor 1 (VEGFR1; Flt-1) levels were reduced in Acvrl1+/- mice and HHT2 patients, suggesting similar mechanisms in humans. In sprouting angiogenesis, VEGFR1 is expressed in stalk cells to inhibit VEGFR2 (Flk-1, KDR) signaling and thus limit tip cell formation. Soluble VEGFR1 (sVEGFR1) is also secreted, creating a VEGF gradient that promotes orientated sprout migration. Acvrl1+/- embryonic stem cell lines recapitulated the vascular anomalies in Acvrl1+/- (HHT2) mice. Genetic insertion of either the membrane or soluble form of VEGFR1 into the ROSA26 locus of Acvrl1+/- embryonic stem cell lines prevented the vascular anomalies, suggesting that high VEGFR2 activity in Acvrl1+/- endothelial cells induces HHT2 vascular anomalies. To confirm our hypothesis, Acvrl1+/- mice were infected by Mycoplasma pulmonis to induce sustained airway inflammation. Infected Acvrl1+/- tracheas showed excessive angiogenesis with the formation of multiple telangiectases, vascular defects that were prevented by VEGFR2 blocking antibodies. CONCLUSIONS: Our findings demonstrate a key role of VEGFR1 in HHT2 pathogenesis and provide mechanisms explaining why HHT2 blood vessels respond abnormally to angiogenic signals. This supports the case for using anti-VEGF therapy in HHT2.


Assuntos
Telangiectasia Hemorrágica Hereditária/patologia , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Receptores de Ativinas Tipo I/genética , Receptores de Activinas Tipo II , Adulto , Animais , Anticorpos/administração & dosagem , Anticorpos/imunologia , Malformações Arteriovenosas/etiologia , Modelos Animais de Doenças , Feminino , Heterozigoto , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Células-Tronco Embrionárias Murinas/citologia , Células-Tronco Embrionárias Murinas/metabolismo , Mycoplasma pulmonis/fisiologia , Neovascularização Fisiológica , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Vasos Retinianos/fisiologia , Transdução de Sinais , Pele/patologia , Telangiectasia Hemorrágica Hereditária/metabolismo , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/genética , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/imunologia
17.
Dis Model Mech ; 11(9)2018 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-30108051

RESUMO

Endoglin is a transmembrane glycoprotein expressed in vascular endothelium that plays a key role in angiogenesis. Mutations in the endoglin gene (ENG) cause hereditary hemorrhagic telangiectasia type 1 (HHT1), characterized by arteriovenous malformations (AVMs) in different organs. These vascular lesions derive from abnormal processes of angiogenesis, whereby aberrant vascular remodeling leads to focal loss of capillaries. Current treatments for HHT1 include antiangiogenic therapies. Interestingly, a circulating form of endoglin (also known as soluble endoglin, sEng), proteolytically released from the membrane-bound protein and displaying antiangiogenic activity, has been described in several endothelial-related pathological conditions. Using human and mouse endothelial cells, we find that sEng downregulates several pro-angiogenic and pro-migratory proteins involved in angiogenesis. However, this effect is much reduced in endothelial cells that lack endogenous transmembrane endoglin, suggesting that the antiangiogenic activity of sEng is dependent on the presence of endogenous transmembrane endoglin protein. In fact, sEng partially restores the phenotype of endoglin-silenced endothelial cells to that of normal endothelial cells. Moreover, using an established neonatal retinal model of HHT1 with depleted endoglin in the vascular endothelium, sEng treatment decreases the number of AVMs and has a normalizing effect on the vascular phenotype with respect to vessel branching, vascular density and migration of the vascular plexus towards the retinal periphery. Taken together, these data show that circulating sEng can influence vascular development and AVMs by modulating angiogenesis, and that its effect on endothelial cells depends on the expression of endogenous endoglin.This article has an associated First Person interview with the first author of the paper.


Assuntos
Malformações Arteriovenosas/genética , Malformações Arteriovenosas/patologia , Endoglina/metabolismo , Regulação da Expressão Gênica , Neovascularização Patológica/genética , Telangiectasia Hemorrágica Hereditária/genética , Telangiectasia Hemorrágica Hereditária/patologia , Animais , Biomarcadores/metabolismo , Movimento Celular , Modelos Animais de Doenças , Endoglina/genética , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Pulmão/patologia , Camundongos Knockout , Modelos Biológicos , Retina/patologia , Solubilidade , Cicatrização
18.
Angiogenesis ; 21(1): 169-181, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29147802

RESUMO

Hereditary hemorrhagic telangiectasia is an autosomal dominant trait affecting approximately 1 in 5000 people. A pathogenic DNA sequence variant in the ENG, ACVRL1 or SMAD4 genes, can be found in the majority of patients. The 12th International Scientific HHT Conference was held on June 8-11, 2017 in Dubrovnik, Croatia to present and discuss the latest scientific achievements, and was attended by over 200 scientific and clinical researchers. In total 174 abstracts were accepted of which 58 were selected for oral presentations. This article covers the basic science and clinical talks, and discussions from three theme-based workshops. We focus on significant emergent themes and unanswered questions. Understanding these topics and answering these questions will help to define the future of HHT research and therapeutics, and ultimately bring us closer to a cure.


Assuntos
Telangiectasia Hemorrágica Hereditária , Receptores de Activinas Tipo II/genética , Receptores de Activinas Tipo II/metabolismo , Malformações Arteriovenosas/genética , Malformações Arteriovenosas/metabolismo , Malformações Arteriovenosas/patologia , Malformações Arteriovenosas/terapia , Croácia , Endoglina/genética , Endoglina/metabolismo , Epistaxe/genética , Epistaxe/metabolismo , Variação Genética , Humanos , Proteína Smad4/genética , Proteína Smad4/metabolismo , Telangiectasia Hemorrágica Hereditária/genética , Telangiectasia Hemorrágica Hereditária/metabolismo , Telangiectasia Hemorrágica Hereditária/patologia , Telangiectasia Hemorrágica Hereditária/terapia
19.
PLoS One ; 12(12): e0189805, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29253907

RESUMO

AIMS: Hereditary Hemorrhagic Telangiectasia type-1 (HHT1) is a genetic vascular disorder caused by haploinsufficiency of the TGFß co-receptor endoglin. Dysfunctional homing of HHT1 mononuclear cells (MNCs) towards the infarcted myocardium hampers cardiac recovery. HHT1-MNCs have elevated expression of dipeptidyl peptidase-4 (DPP4/CD26), which inhibits recruitment of CXCR4-expressing MNCs by inactivation of stromal cell-derived factor 1 (SDF1). We hypothesize that inhibiting DPP4 will restore homing of HHT1-MNCs to the infarcted heart and improve cardiac recovery. METHODS AND RESULTS: After inducing myocardial infarction (MI), wild type (WT) and endoglin heterozygous (Eng+/-) mice were treated for 5 days with the DPP4 inhibitor Diprotin A (DipA). DipA increased the number of CXCR4+ MNCs residing in the infarcted Eng+/- hearts (Eng+/- 73.17±12.67 vs. Eng+/- treated 157.00±11.61, P = 0.0003) and significantly reduced infarct size (Eng+/- 46.60±9.33% vs. Eng+/- treated 27.02±3.04%, P = 0.03). Echocardiography demonstrated that DipA treatment slightly deteriorated heart function in Eng+/- mice. An increased number of capillaries (Eng+/- 61.63±1.43 vs. Eng+/- treated 74.30±1.74, P = 0.001) were detected in the infarct border zone whereas the number of arteries was reduced (Eng+/- 11.88±0.63 vs. Eng+/- treated 6.38±0.97, P = 0.003). Interestingly, while less M2 regenerative macrophages were present in Eng+/- hearts prior to DipA treatment, (WT 29.88±1.52% vs. Eng+/- 12.34±1.64%, P<0.0001), DPP4 inhibition restored the number of M2 macrophages to wild type levels. CONCLUSIONS: In this study, we demonstrate that systemic DPP4 inhibition restores the impaired MNC homing in Eng+/- animals post-MI, and enhances cardiac repair, which might be explained by restoring the balance between the inflammatory and regenerative macrophages present in the heart.


Assuntos
Dipeptidil Peptidase 4/química , Inibidores da Dipeptidil Peptidase IV/química , Macrófagos/metabolismo , Infarto do Miocárdio/metabolismo , Telangiectasia Hemorrágica Hereditária/genética , Animais , Quimiocina CXCL12/metabolismo , Modelos Animais de Doenças , Endoglina/metabolismo , Fibrose/metabolismo , Haploinsuficiência , Ventrículos do Coração/patologia , Heterozigoto , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Infarto do Miocárdio/complicações , Miocárdio/metabolismo , Miocárdio/patologia , Regeneração , Telangiectasia Hemorrágica Hereditária/patologia , Fator de Crescimento Transformador beta/metabolismo
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