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1.
Nat Commun ; 12(1): 4950, 2021 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-34400635

RESUMO

Upon ligand binding, bone morphogenetic protein (BMP) receptors form active tetrameric complexes, comprised of two type I and two type II receptors, which then transmit signals to SMAD proteins. The link between receptor tetramerization and the mechanism of kinase activation, however, has not been elucidated. Here, using hydrogen deuterium exchange mass spectrometry (HDX-MS), small angle X-ray scattering (SAXS) and molecular dynamics (MD) simulations, combined with analysis of SMAD signaling, we show that the kinase domain of the type I receptor ALK2 and type II receptor BMPR2 form a heterodimeric complex via their C-terminal lobes. Formation of this dimer is essential for ligand-induced receptor signaling and is targeted by mutations in BMPR2 in patients with pulmonary arterial hypertension (PAH). We further show that the type I/type II kinase domain heterodimer serves as the scaffold for assembly of the active tetrameric receptor complexes to enable phosphorylation of the GS domain and activation of SMADs.


Assuntos
Receptores de Ativinas Tipo I/química , Receptores de Ativinas Tipo I/metabolismo , Receptores de Proteínas Morfogenéticas Ósseas Tipo II/química , Receptores de Proteínas Morfogenéticas Ósseas Tipo II/metabolismo , Transdução de Sinais/fisiologia , Receptores de Ativinas Tipo I/genética , Receptores de Proteínas Morfogenéticas Ósseas/metabolismo , Receptores de Proteínas Morfogenéticas Ósseas Tipo II/genética , Proteínas Morfogenéticas Ósseas/metabolismo , Hipertensão Pulmonar Primária Familiar/metabolismo , Humanos , Ligantes , Modelos Moleculares , Mutação , Fosforilação , Ligação Proteica , Domínios Proteicos , Hipertensão Arterial Pulmonar , Espalhamento a Baixo Ângulo , Transdução de Sinais/genética , Proteínas Smad/metabolismo , Difração de Raios X
2.
FASEB J ; 35(8): e21759, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34245608

RESUMO

Life-style change and anti-inflammatory interventions have only transient effects in obesity. It is not clear how benefits obtained by these treatments can be maintained longer term, especially during sustained high caloric intake. Constitutive ablation of the activin receptor ALK7 in adipose tissue enhances catecholamine signaling and lipolysis in adipocytes, and protects mice from diet-induced obesity. Here, we investigated the consequences of conditional ALK7 ablation in adipocytes of adult mice with pre-existing obesity. Although ALK7 deletion had little effect on its own, it synergized strongly with a transient switch to low-fat diet (life-style change) or anti-inflammatory treatment (Na-salicylate), resulting in enhanced lipolysis, increased energy expenditure, and reduced adipose tissue mass and body weight gain, even under sustained high caloric intake. By themselves, diet-switch and salicylate had only a temporary effect on weight gain. Mechanistically, combination of ALK7 ablation with either treatment strongly enhanced the levels of ß3-AR, the main adrenergic receptor for catecholamine stimulation of lipolysis, and C/EBPα, an upstream regulator of ß3-AR expression. These results suggest that inhibition of ALK7 can be combined with simple interventions to produce longer-lasting benefits in obesity.


Assuntos
Receptores de Ativinas Tipo I/deficiência , Adipócitos/metabolismo , Ingestão de Alimentos , Lipólise , Obesidade/metabolismo , Receptores de Ativinas Tipo I/metabolismo , Adipócitos/patologia , Animais , Camundongos , Camundongos Transgênicos , Obesidade/genética , Obesidade/patologia , Salicilatos/farmacologia
3.
Bioorg Med Chem Lett ; 38: 127858, 2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33609658

RESUMO

Mutant activin receptor-like kinase-2 (ALK2) is associated with the pathogenesis of fibrodysplasia ossificans progressiva, making it an attractive target for therapeutic intervention. We synthesized a new series of bicyclic pyrazoles and evaluated their mutant ALK2 enzyme inhibitory activities, leading to the identification of 8 as the most potent inhibitor. This compound showed moderate microsomal metabolic stability and human ether-a-go-go related gene (hERG) safety. In C2C12 cells carrying mutant ALK2 (R206H), 8 efficiently inhibited the bone morphogenetic protein (BMP)-induced alkaline phosphatase activity.


Assuntos
Receptores de Ativinas Tipo I/antagonistas & inibidores , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Miosite Ossificante/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Pirazóis/farmacologia , Receptores de Ativinas Tipo I/genética , Receptores de Ativinas Tipo I/metabolismo , Animais , Compostos Bicíclicos Heterocíclicos com Pontes/síntese química , Compostos Bicíclicos Heterocíclicos com Pontes/química , Linhagem Celular , Relação Dose-Resposta a Droga , Humanos , Camundongos , Estrutura Molecular , Mutação , Miosite Ossificante/metabolismo , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Pirazóis/síntese química , Pirazóis/química , Relação Estrutura-Atividade
4.
Immunity ; 54(2): 308-323.e6, 2021 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-33421362

RESUMO

Th17 cells are known to exert pathogenic and non-pathogenic functions. Although the cytokine transforming growth factor ß1 (TGF-ß1) is instrumental for Th17 cell differentiation, it is dispensable for generation of pathogenic Th17 cells. Here, we examined the T cell-intrinsic role of Activin-A, a TGF-ß superfamily member closely related to TGF-ß1, in pathogenic Th17 cell differentiation. Activin-A expression was increased in individuals with relapsing-remitting multiple sclerosis and in mice with experimental autoimmune encephalomyelitis. Stimulation with interleukin-6 and Activin-A induced a molecular program that mirrored that of pathogenic Th17 cells and was inhibited by blocking Activin-A signaling. Genetic disruption of Activin-A and its receptor ALK4 in T cells impaired pathogenic Th17 cell differentiation in vitro and in vivo. Mechanistically, extracellular-signal-regulated kinase (ERK) phosphorylation, which was essential for pathogenic Th17 cell differentiation, was suppressed by TGF-ß1-ALK5 but not Activin-A-ALK4 signaling. Thus, Activin-A drives pathogenic Th17 cell differentiation, implicating the Activin-A-ALK4-ERK axis as a therapeutic target for Th17 cell-related diseases.


Assuntos
Ativinas/metabolismo , Encefalomielite Autoimune Experimental/imunologia , Esclerose Múltipla/imunologia , Inflamação Neurogênica/imunologia , Células Th17/imunologia , Fator de Crescimento Transformador beta/metabolismo , Receptores de Ativinas Tipo I/genética , Receptores de Ativinas Tipo I/metabolismo , Ativinas/genética , Animais , Diferenciação Celular , Células Cultivadas , Humanos , Camundongos , Camundongos Knockout , Terapia de Alvo Molecular , Transdução de Sinais
5.
Orphanet J Rare Dis ; 16(1): 54, 2021 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-33516233

RESUMO

BACKGROUND: Pain is a highly prevalent symptom experienced by patients across numerous rare musculoskeletal conditions. Much remains unknown regarding the central, neurobiological processes associated with clinical pain in musculoskeletal disease states. Fibrodysplasia ossificans progressiva (FOP) is an inherited condition characterized by substantial physical disability and pain. FOP arises from mutations of the bone morphogenetic protein (BMP) receptor Activin A receptor type 1 (ACVR1) causing patients to undergo painful flare-ups as well as heterotopic ossification (HO) of skeletal muscles, tendons, ligaments, and fascia. To date, the neurobiological processes that underlie pain in FOP have rarely been investigated. We examined pain and central pain mechanism in FOP as a model primary musculoskeletal condition. Central nervous system (CNS) functional properties were investigated in FOP patients (N = 17) stratified into low (0-3; 0-10 Scale) and high (≥ 4) pain cohorts using functional near-infrared spectroscopy (fNIRS). Associations among clinical pain, mental health, and physical health were also quantified using responses derived from a battery of clinical questionnaires. RESULTS: Resting-state fNIRS revealed suppressed power of hemodynamic activity within the slow-5 frequency sub-band (0.01-0.027 Hz) in the prefrontal cortex in high pain FOP patients, where reduced power of slow-5, prefrontal cortex oscillations exhibited robust negative correlations with pain levels. Higher clinical pain intensities were also associated with higher magnitudes of depressive symptoms. CONCLUSIONS: Our findings not only demonstrate a robust coupling among prefrontal cortex functionality and clinical pain in FOP but lays the groundwork for utilizing fNIRS to objectively monitor and central pain mechanisms in FOP and other musculoskeletal disorders.


Assuntos
Miosite Ossificante , Ossificação Heterotópica , Receptores de Ativinas Tipo I/genética , Receptores de Ativinas Tipo I/metabolismo , Humanos , Mutação , Miosite Ossificante/genética , Dor , Córtex Pré-Frontal/metabolismo
6.
Int J Mol Sci ; 22(3)2021 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-33499275

RESUMO

Activin A receptor type 1C (ACVR1C), a type I transforming growth factor-ß (TGF-ß) receptor, has been implicated in sensitive skin and psoriasis and is involved in the regulation of metabolic homeostasis as well as cell proliferation and differentiation. In this study, we identified a novel role of ACVR1C in the ultraviolet (UV)-irradiation-induced reduction of epidermal lipogenesis in human skin. UV irradiation decreased ACVR1C expression and epidermal triglyceride (TG) synthesis in human skin in vivo and in primary normal human epidermal keratinocytes (NHEK) in vitro. Lipogenic genes, including genes encoding acetyl-CoA carboxylase (ACC) and sterol regulatory element binding protein-1 (SREBP1), were significantly downregulated in UV-irradiated NHEK. ACVR1C knockdown by shRNA resulted in greater decreases in SREBP1 and ACC in response to UV irradiation. Conversely, the overexpression of ACVR1C attenuated the UV-induced decreases in SREBP1 and ACC. Further mechanistic study revealed that SMAD2 phosphorylation mediated the ACVR1C-induced lipogenic gene modulation. Taken together, a decrease in ACVR1C may cause UV-induced reductions in SREBP1 and ACC as well as epidermal TG synthesis via the suppression of SMAD2 phosphorylation. ACVR1C may be a target for preventing or treating UV-induced disruptions in lipid metabolism and associated skin disorders.


Assuntos
Acetil-CoA Carboxilase/metabolismo , Receptores de Ativinas Tipo I/metabolismo , Epiderme/metabolismo , Queratinócitos/metabolismo , Proteína Smad2/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Adulto , Diferenciação Celular , Proliferação de Células , Epiderme/efeitos da radiação , Voluntários Saudáveis , Humanos , Queratinócitos/efeitos da radiação , Metabolismo dos Lipídeos , Lipogênese/genética , Fosforilação , Interferência de RNA , Pele/metabolismo , Triglicerídeos/química , Raios Ultravioleta
7.
FASEB J ; 35(2): e21220, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33230889

RESUMO

Activin A promotes human trophoblast invasion during the first trimester of pregnancy and is associated with preeclampsia and pregnancy-induced hypertension (PE/PIH) in naturally conceived pregnancies. However, whether integrin ß1 mediates activin A-increased trophoblast invasion remains unknown and the evidence is limited regarding the predictive value of activin A for PE/PIH in women receiving in vitro fertilization (IVF) treatment. Here, we studied the role and underlying molecular mechanisms of integrin ß1 in activin A-promoted invasion in immortalized (HTR8/SVneo) and primary human extravillous trophoblast (EVT) cells. A nest case-control study was designed to investigate the predictive/diagnostic value of activin A in IVF pregnancies. Results showed that integrin ß1 expression increased after activin A treatment and knockdown of integrin ß1 significantly decreased both basal and activin A-increased HTR8/SVneo cell invasion. SB431542 (TGF-ß type I receptors inhibitor) abolished activin A-induced SMAD2/SMAD3 phosphorylation and integrin ß1 overexpression. Activin A-upregulated integrin ß1 expression was attenuated after the depletion of ALK4 or SMAD4 in both HTR8/SVneo and primary EVT cells. Furthermore, we found similar first-trimester activin A levels in IVF patients with or without subsequent PE/PIH. These results reveal that integrin ß1 mediates activin A-promoted trophoblast invasion through ALK4-activated SMAD2/3-SMAD4 pathway, and the predictive/diagnostic value of first-trimester maternal serum activin A for hypertensive disorders of pregnancy might be different in IVF population.


Assuntos
Receptores de Ativinas Tipo I/metabolismo , Ativinas/farmacologia , Movimento Celular , Integrina beta1/metabolismo , Trofoblastos/metabolismo , Adulto , Benzamidas/farmacologia , Linhagem Celular , Células Cultivadas , Dioxóis/farmacologia , Feminino , Humanos , Integrina beta1/genética , Gravidez , Proteínas Smad/metabolismo , Trofoblastos/efeitos dos fármacos , Trofoblastos/fisiologia , Regulação para Cima
8.
Dev Biol ; 470: 136-146, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33217406

RESUMO

The development of joints in the mammalian skeleton depends on the precise regulation of multiple interacting signaling pathways including the bone morphogenetic protein (BMP) pathway, a key regulator of joint development, digit patterning, skeletal growth, and chondrogenesis. Mutations in the BMP receptor ACVR1 cause the rare genetic disease fibrodysplasia ossificans progressiva (FOP) in which extensive and progressive extra-skeletal bone forms in soft connective tissues after birth. These mutations, which enhance BMP-pSmad1/5 pathway activity to induce ectopic bone, also affect skeletal development. FOP can be diagnosed at birth by symmetric, characteristic malformations of the great toes (first digits) that are associated with decreased joint mobility, shortened digit length, and absent, fused, and/or malformed phalanges. To elucidate the role of ACVR1-mediated BMP signaling in digit skeletal development, we used an Acvr1R206H/+;Prrx1-Cre knock-in mouse model that mimics the first digit phenotype of human FOP. We have determined that the effects of increased Acvr1-mediated signaling by the Acvr1R206H mutation are not limited to the first digit but alter BMP signaling, Gdf5+ joint progenitor cell localization, and joint development in a manner that differently affects individual digits during embryogenesis. The Acvr1R206H mutation leads to delayed and disrupted joint specification and cleavage in the digits and alters the development of cartilage and endochondral ossification at sites of joint morphogenesis. These findings demonstrate an important role for ACVR1-mediated BMP signaling in the regulation of joint and skeletal formation, show a direct link between failure to restrict BMP signaling in the digit joint interzone and failure of joint cleavage at the presumptive interzone, and implicate impaired, digit-specific joint development as the proximal cause of digit malformation in FOP.


Assuntos
Receptores de Ativinas Tipo I/metabolismo , Proteínas Morfogenéticas Ósseas/metabolismo , Articulações/embriologia , Miosite Ossificante/embriologia , Miosite Ossificante/metabolismo , Dedos do Pé/embriologia , Animais , Padronização Corporal , Condrogênese , Modelos Animais de Doenças , Membro Anterior/anormalidades , Membro Anterior/embriologia , Fator 5 de Diferenciação de Crescimento/metabolismo , Lâmina de Crescimento/embriologia , Membro Posterior/anormalidades , Membro Posterior/embriologia , Articulações/anormalidades , Articulações/metabolismo , Camundongos , Osteogênese , Transdução de Sinais , Proteína Smad1/metabolismo , Proteína Smad5/metabolismo , Células-Tronco/fisiologia , Dedos do Pé/anormalidades
9.
Exp Neurol ; 337: 113574, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33345977

RESUMO

Activin A plays important roles in ischemic injury and white matter remyelination, but its mechanisms are unclear. In this study, the adult male C57BL/6 J mice were used to establish the model of 1 h middle cerebral artery occlusion/reperfusion (MCAO/R) 1 d to 28 d-induced ischemic stroke in vivo. We found that the neurological outcome was positively correlated with the levels of myelin associated proteins (include MAG, CNPase, MOG and MBP, n = 6 per group) both in corpus callosum and internal capsule of mice with ischemic stroke. The dynamic changes of Luxol fast blue (LFB) staining intensity, oligodendrocyte (CC1+) and proliferated oligodendrocyte precursor (Ki67+/PDGFRα+) cell numbers indicated demyelination and spontaneous remyelination occurred in the corpus callosum of mice after 1 h MCAO/R 1 d-28 d (n = 6 per group). Activin receptor type I (ACVR1) inhibitor SB431542 aggregated neurological deficits, and reduced MAG, MOG and MBP protein levels of mice with ischemic stroke (n = 6 per group). Meanwhile, recombinant mouse (rm) Activin A enhanced the neurological function recovery, MAG, MOG and MBP protein levels of mice with 1 h MCAO/R 28 d. In addition, the injection of AAV-based ACVR1B shRNA with Olig2 promoter could reverse rmActivin A-induced the increases of CC1+ cell number, LFB intensity, MAG, MOG and MBP protein levels in the corpus callosum (n = 6 per group), and neurological function recovery (n = 10 per group) of mice with 1 h MCAO/R 28 d. These results suggested that Activin A improves the neurological outcome through promoting oligodendroglial ACVR1B-mediated white matter remyelination of mice with ischemic stroke, which may provide a potential therapeutic strategy for ischemic stroke.


Assuntos
Receptores de Ativinas Tipo I/metabolismo , Ativinas/uso terapêutico , AVC Isquêmico/tratamento farmacológico , Bainha de Mielina/efeitos dos fármacos , Fármacos Neuroprotetores/uso terapêutico , Oligodendroglia/efeitos dos fármacos , Substância Branca/patologia , Receptores de Ativinas Tipo I/genética , Animais , Contagem de Células , Proliferação de Células/efeitos dos fármacos , Corpo Caloso/patologia , Doenças Desmielinizantes/tratamento farmacológico , Doenças Desmielinizantes/patologia , AVC Isquêmico/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Bainha de Mielina/patologia , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/genética , Traumatismo por Reperfusão/patologia , Resultado do Tratamento
10.
Artigo em Japonês | MEDLINE | ID: mdl-33342936

RESUMO

Renal tubular cell death is caused by various extracellular stresses including toxic amounts of cadmium, an occupational and environmental pollutant metal, and is responsible for renal dysfunction. While cadmium exposure disrupts many intracellular signaling pathways, the molecular mechanism underlying cadmium-induced renal tubular cell death has not yet been fully elucidated. We have recently identified two important intracellular signaling pathways that promote cadmium-induced renal tubular cell death: the Notch1 signaling and activin receptor-like kinase (ALK) 4/5 signaling (also known as the activin-transforming growth factor ß receptor pathways). In this review paper, we introduce our previous experimental findings, focusing on Notch1 and ALK4/5 signaling pathways, which may uncover the molecular mechanisms involved in cadmium-induced renal tubular cell death.


Assuntos
Receptores de Ativinas Tipo I/metabolismo , Cádmio/toxicidade , Morte Celular/efeitos dos fármacos , Morte Celular/genética , Poluentes Ambientais/toxicidade , Túbulos Renais/citologia , Túbulos Renais/patologia , Exposição Ocupacional/efeitos adversos , Receptor Notch1/metabolismo , Receptor do Fator de Crescimento Transformador beta Tipo I/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Animais , Humanos , Camundongos , Ratos
11.
Proc Natl Acad Sci U S A ; 117(49): 30907-30917, 2020 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-33219121

RESUMO

Myostatin (MSTN) is a transforming growth factor-ß (TGF-ß) family member that normally acts to limit muscle growth. The function of MSTN is partially redundant with that of another TGF-ß family member, activin A. MSTN and activin A are capable of signaling through a complex of type II and type I receptors. Here, we investigated the roles of two type II receptors (ACVR2 and ACVR2B) and two type I receptors (ALK4 and ALK5) in the regulation of muscle mass by these ligands by genetically targeting these receptors either alone or in combination specifically in myofibers in mice. We show that targeting signaling in myofibers is sufficient to cause significant increases in muscle mass, showing that myofibers are the direct target for signaling by these ligands in the regulation of muscle growth. Moreover, we show that there is functional redundancy between the two type II receptors as well as between the two type I receptors and that all four type II/type I receptor combinations are utilized in vivo. Targeting signaling specifically in myofibers also led to reductions in overall body fat content and improved glucose metabolism in mice fed either regular chow or a high-fat diet, demonstrating that these metabolic effects are the result of enhanced muscling. We observed no effect, however, on either bone density or muscle regeneration in mice in which signaling was targeted in myofibers. The latter finding implies that MSTN likely signals to other cells, such as satellite cells, in addition to myofibers to regulate muscle homeostasis.


Assuntos
Receptores de Activinas Tipo II/metabolismo , Receptores de Ativinas Tipo I/metabolismo , Ativinas/metabolismo , Desenvolvimento Muscular , Miostatina/metabolismo , Animais , Camundongos Endogâmicos C57BL , Fibras Musculares Esqueléticas/metabolismo , Músculos/metabolismo , Tamanho do Órgão
12.
FASEB J ; 34(12): 16129-16143, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33047388

RESUMO

Locally produced in human granulosa cells of the developing follicle, bone morphogenetic protein 2 (BMP2) plays a crucial role in the regulation of ovarian folliculogenesis and luteal formation. Brain-derived neurotrophic factor (BDNF) is an intraovarian neurotrophic factor that has been shown to promote oocyte maturation and subsequent fertilization competency. At present, little is known regarding the intracellular regulation, assembly and secretion of endogenous BDNF in human granulosa cells. The aim of this study was to explore the effect of BMP2 on the expression and production of BDNF in human granulosa cells and the molecular mechanisms underlying this effect. An immortalized human granulosa cell line (SVOG) and primary human granulosa-lutein (hGL) cells were utilized as in vitro study models. Our results showed that BMP2 significantly increased the mRNA and secreted levels of BDNF. Additionally, BMP2 upregulated the expression of furin at the transcriptional and translational levels. Knockdown of endogenous furin partially attenuated the BMP2-induced increase in BDNF production, indicating that furin is involved in the maturation process of BDNF. Using pharmacological (kinase receptor inhibitors) and siRNA-mediated inhibition approaches, we demonstrated that BMP2-induced upregulation of BDNF and furin expression is most likely mediated by the activin receptor-like kinase (ALK)2/ALK3-SMAD4 signaling pathway. Notably, analysis using clinical samples revealed that there was a positive correlation between follicular fluid concentrations of BMP2 and those of BDNF. These results indicate that BMP2 increases the production of mature BDNF by upregulating the precursor BDNF and promoting the proteolytic processing of mature BDNF. Finally, we also investigated the effects of BMP2 on ovarian steroidogenesis and the results showed that BMP2 treatment significantly increased the accumulated level of estradiol (by upregulating the expression of FSH receptor and cytochrome P450 aromatase), whereas it decreased the accumulated level of progesterone (by downregulating the expression of LH receptors and steroidogenic acute regulatory protein) in primary hGL cells. Our findings provide a novel paracrine mechanism underlying the regulation of an intraovarian growth factor in human granulosa cells.


Assuntos
Proteína Morfogenética Óssea 2/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Furina/metabolismo , Células da Granulosa/metabolismo , Células Lúteas/metabolismo , Regulação para Cima/fisiologia , Receptores de Ativinas Tipo I/metabolismo , Adulto , Receptores de Proteínas Morfogenéticas Ósseas Tipo I/metabolismo , Células Cultivadas , Regulação para Baixo/fisiologia , Feminino , Humanos , Ovário/metabolismo , Fosfoproteínas/metabolismo , Progesterona/metabolismo , Transdução de Sinais/fisiologia , Proteína Smad4/metabolismo
13.
Int J Mol Sci ; 21(18)2020 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-32899497

RESUMO

Activins transduce the TGF-ß pathway through a heteromeric signaling complex consisting of type I and type II receptors, and activins also inhibit bone morphogenetic protein (BMP) signaling mediated by type I receptor ALK2. Recent studies indicated that activin A cross-activates the BMP pathway through ALK2R206H, a mutation associated with Fibrodysplasia Ossificans Progressiva (FOP). How activin A inhibits ALK2WT-mediated BMP signaling but activates ALK2R206H-mediated BMP signaling is not well understood, and here we offer some insights into its molecular mechanism. We first demonstrated that among four BMP type I receptors, ALK2 is the only subtype able to mediate the activin A-induced BMP signaling upon the dissociation of FKBP12. We further showed that BMP4 does not cross-signal TGF-ß pathway upon FKBP12 inhibition. In addition, although the roles of type II receptors in the ligand-independent BMP signaling activated by FOP-associated mutant ALK2 have been reported, their roles in activin A-induced BMP signaling remains unclear. We demonstrated in this study that the known type II BMP receptors contribute to activin A-induced BMP signaling through their kinase activity. Together, the current study provided important mechanistic insights at the molecular level into further understanding physiological and pathophysiological BMP signaling.


Assuntos
Receptores de Ativinas Tipo I/metabolismo , Ativinas/metabolismo , Proteínas Morfogenéticas Ósseas/metabolismo , Receptores de Ativinas Tipo I/genética , Receptores de Activinas Tipo II/genética , Receptores de Activinas Tipo II/metabolismo , Ativinas/fisiologia , Animais , Receptores de Proteínas Morfogenéticas Ósseas Tipo I/genética , Receptores de Proteínas Morfogenéticas Ósseas Tipo II/genética , Proteínas Morfogenéticas Ósseas/fisiologia , Diferenciação Celular/fisiologia , Linhagem Celular , Regulação da Expressão Gênica/genética , Células HEK293 , Células Hep G2 , Humanos , Camundongos , Ossificação Heterotópica/genética , Fosforilação , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Fator de Crescimento Transformador beta/metabolismo
14.
Elife ; 92020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32897189

RESUMO

Fibrodysplasia ossificans progressiva (FOP) is a rare human genetic disorder characterized by altered skeletal development and extraskeletal ossification. All cases of FOP are caused by activating mutations in the type I BMP/TGFß cell surface receptor ACVR1, which over-activates signaling through phospho-Smad1/5 (pSmad1/5). To investigate the mechanism by which FOP-ACVR1 enhances pSmad1/5 activation, we used zebrafish embryonic dorsoventral (DV) patterning as an assay for BMP signaling. We determined that the FOP mutants ACVR1-R206H and -G328R do not require their ligand binding domain to over-activate BMP signaling in DV patterning. However, intact ACVR1-R206H has the ability to respond to both Bmp7 and Activin A ligands. Additionally, BMPR1, a type I BMP receptor normally required for BMP-mediated patterning of the embryo, is dispensable for both ligand-independent signaling pathway activation and ligand-responsive signaling hyperactivation by ACVR1-R206H. These results demonstrate that FOP-ACVR1 is not constrained by the same receptor/ligand partner requirements as WT-ACVR1.


Assuntos
Receptores de Ativinas Tipo I/genética , Proteínas de Peixes/genética , Miosite Ossificante/genética , Peixe-Zebra/genética , Receptores de Ativinas Tipo I/metabolismo , Animais , Modelos Animais de Doenças , Embrião não Mamífero/metabolismo , Proteínas de Peixes/metabolismo , Miosite Ossificante/metabolismo , Peixe-Zebra/embriologia , Peixe-Zebra/crescimento & desenvolvimento , Peixe-Zebra/metabolismo
15.
Circ Res ; 127(9): e210-e231, 2020 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-32755283

RESUMO

RATIONALE: Brain arteriovenous malformations (AVMs) are abnormal tangles of vessels where arteries and veins directly connect without intervening capillary nets, increasing the risk of intracerebral hemorrhage and stroke. Current treatments are highly invasive and often not feasible. Thus, effective noninvasive treatments are needed. We previously showed that AVM-brain endothelial cells (BECs) secreted higher VEGF (vascular endothelial growth factor) and lower TSP-1 (thrombospondin-1) levels than control BEC; and that microRNA-18a (miR-18a) normalized AVM-BEC function and phenotype, although its mechanism remained unclear. OBJECTIVE: To elucidate the mechanism of action and potential clinical application of miR-18a as an effective noninvasive treatment to selectively restore the phenotype and functionality of AVM vasculature. METHODS AND RESULTS: The molecular pathways affected by miR-18a in patient-derived BECs and AVM-BECs were determined by Western blot, RT-qPCR (quantitative reverse transcription polymerase chain reaction), ELISA, co-IP, immunostaining, knockdown and overexpression studies, flow cytometry, and luciferase reporter assays. miR-18a was shown to increase TSP-1 and decrease VEGF by reducing PAI-1 (plasminogen activator inhibitor-1/SERPINE1) levels. Furthermore, miR-18a decreased the expression of BMP4 (bone morphogenetic protein 4) and HIF-1α (hypoxia-inducible factor 1α), blocking the BMP4/ALK (activin-like kinase) 2/ALK1/ALK5 and Notch signaling pathways. As determined by Boyden chamber assays, miR-18a also reduced the abnormal AVM-BEC invasiveness, which correlated with a decrease in MMP2 (matrix metalloproteinase 2), MMP9, and ADAM10 (ADAM metallopeptidase domain 10) levels. In vivo pharmacokinetic studies showed that miR-18a reaches the brain following intravenous and intranasal administration. Intranasal co-delivery of miR-18a and NEO100, a good manufacturing practices-quality form of perillyl alcohol, improved the pharmacokinetic profile of miR-18a in the brain without affecting its pharmacological properties. Ultra-high-resolution computed tomography angiography and immunostaining studies in an Mgp-/- AVM mouse model showed that miR-18a decreased abnormal cerebral vasculature and restored the functionality of the bone marrow, lungs, spleen, and liver. CONCLUSIONS: miR-18a may have significant clinical value in preventing, reducing, and potentially reversing AVM.


Assuntos
Proteína Morfogenética Óssea 4/antagonistas & inibidores , Células Endoteliais/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/antagonistas & inibidores , Malformações Arteriovenosas Intracranianas/terapia , MicroRNAs/uso terapêutico , Trombospondina 1/metabolismo , Fatores de Crescimento do Endotélio Vascular/metabolismo , Proteína ADAM10/metabolismo , Receptores de Ativinas Tipo I/metabolismo , Receptores de Activinas Tipo II/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Encéfalo/irrigação sanguínea , Encéfalo/metabolismo , Humanos , Malformações Arteriovenosas Intracranianas/genética , Malformações Arteriovenosas Intracranianas/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Proteínas de Membrana/metabolismo , Camundongos , Monoterpenos/administração & dosagem , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Receptor do Fator de Crescimento Transformador beta Tipo I/metabolismo
16.
Bone ; 140: 115549, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32730927

RESUMO

The Bone Morphogenetic Proteins (BMPs) are the largest class signaling molecules within the greater Transforming Growth Factor Beta (TGFß) family, and are responsible for a wide array of biological functions, including dorsal-ventral patterning, skeletal development and maintenance, as well as cell homeostasis. As such, dysregulation of BMPs results in a number of diseases, including fibrodysplasia ossificans progressiva (FOP) and pulmonary arterial hypertension (PAH). Therefore, understanding BMP signaling and regulation at the molecular level is essential for targeted therapeutic intervention. This review discusses the recent advances in the structural and biochemical characterization of BMPs, from canonical ligand-receptor interactions to co-receptors and antagonists. This work aims to highlight how BMPs differ from other members of the TGFß family, and how that information can be used to further advance the field. Lastly, this review discusses several gaps in the current understanding of BMP structures, with the aim that discussion of these gaps will lead to advancements in the field.


Assuntos
Proteínas Morfogenéticas Ósseas , Miosite Ossificante , Receptores de Ativinas Tipo I/metabolismo , Humanos , Ligantes , Transdução de Sinais , Fator de Crescimento Transformador beta
17.
Elife ; 92020 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-32515349

RESUMO

Activin A functions in BMP signaling in two ways: it either engages ACVR1B to activate Smad2/3 signaling or binds ACVR1 to form a non-signaling complex (NSC). Although the former property has been studied extensively, the roles of the NSC remain unexplored. The genetic disorder fibrodysplasia ossificans progressiva (FOP) provides a unique window into ACVR1/Activin A signaling because in that disease Activin can either signal through FOP-mutant ACVR1 or form NSCs with wild-type ACVR1. To explore the role of the NSC, we generated 'agonist-only' Activin A muteins that activate ACVR1B but cannot form the NSC with ACVR1. Using one of these muteins, we demonstrate that failure to form the NSC in FOP results in more severe disease pathology. These results provide the first evidence for a biological role for the NSC in vivo and pave the way for further exploration of the NSC's physiological role in corresponding knock-in mice.


Assuntos
Receptores de Ativinas Tipo I/metabolismo , Ativinas/metabolismo , Proteínas Morfogenéticas Ósseas/metabolismo , Miosite Ossificante/genética , Transdução de Sinais/genética , Receptores de Ativinas Tipo I/genética , Ativinas/genética , Animais , Receptores de Proteínas Morfogenéticas Ósseas Tipo II/genética , Receptores de Proteínas Morfogenéticas Ósseas Tipo II/metabolismo , Proteínas Morfogenéticas Ósseas/genética , Técnicas de Introdução de Genes , Camundongos , Camundongos Transgênicos , Mutação , Miosite Ossificante/patologia
18.
Bone ; 138: 115472, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32522605

RESUMO

Bone morphogenetic proteins (BMPs) are secreted cytokines that control the fate and function of many different cell types. They exert their cellular responses via heteromeric complexes of specific BMP type I and type II serine/threonine kinase receptors, e.g. BMPRIA and BMPRII. Three type II and four type I receptors, also termed activin receptor-like kinases (ALKs), have been identified. The constitutively active type II kinase phosphorylates the type I receptor, which upon activation initiates intracellular signaling by phosphorylating SMAD effectors. Auxiliary cell surface receptors without intrinsic enzymatic motifs, such as Endoglin and Repulsive guidance molecules (RGM), can fine-tune signaling by regulating the interaction of the BMP ligands with the BMPRs. The functional annotation of the BMPR encoding genes has helped to understand underlying mechanisms of diseases in which these genes are mutated. Loss of function mutations in BMPRII, Endoglin or RGMc are causally linked to pulmonary arterial hypertension, hereditary hemorrhagic telangiectasia and juvenile hemochromatosis, respectively. In contrast, gain of function mutations in ACVR1, encoding ALK2, are linked to Fibrodysplasia ossificans progressiva and diffuse intrinsic pontine glioma. Here, we discuss BMPR identification, structure and function in health and disease. Moreover, we highlight the therapeutic promise of small chemical compounds that act as selective BMPR kinase inhibitors to normalize overactive BMPR signaling.


Assuntos
Miosite Ossificante , Receptores de Ativinas Tipo I/metabolismo , Receptores de Proteínas Morfogenéticas Ósseas , Proteínas Morfogenéticas Ósseas/metabolismo , Humanos , Fosforilação , Transdução de Sinais
19.
Biochem Biophys Res Commun ; 528(2): 299-304, 2020 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-32473755

RESUMO

The pathogenesis of primary focal hyperhidrosis (PFH) is still not clear. PFH is thought to be a genetic disease. Whether activin A receptor type 1 (ACVR1) is involved in the pathogenesis of PFH is unknown. In this study, the expression of ACVR1 in sweat glands of patients with PAH was detected by western blot and immunofluorescence. The primary sweat gland cells obtained from primary axillary hyperhidrosis (PAH) patients were transfected with acvr1 vector. Cell proliferation, apoptosis and cell cycling of gland cells were measured after transfection with acvr1 vector. The mRNA and protein expression of aquaporin 5 (AQP5) and Na:K:2Cl Cotransporter 1 (NKCC1/SLC12A2) were detected. Our data showed that ACVR1 expression in axillary sweat gland tissue of PAH patients was significantly higher than that of normal control group. The function of ACVR1 was further investigated in the gland cells obtained from PAH patients. Compared with NC group, ACVR1 overexpression significantly promoted the proliferation of sweat gland cells and inhibited the apoptosis of sweat gland cells. Meanwhile, ACVR1 overexpression significantly reduced the percentage of cells in G0/G1 and G2/M phases, and increased the percentage of cells in S phase. In addition, ACVR1 overexpression significantly promoted the expression of AQP5 and NKCC1 at both mRNA and protein levels. Together, ACVR1 expression is related to PFH and ACVR1 overexpression can promote the proliferation of sweat gland cells and inhibit apoptosis by promoting the expression of AQP5 and NKCC1.


Assuntos
Receptores de Ativinas Tipo I/metabolismo , Hiperidrose/metabolismo , Hiperidrose/patologia , Apoptose , Aquaporina 5/genética , Aquaporina 5/metabolismo , Proliferação de Células , Regulação da Expressão Gênica , Humanos , Hiperidrose/genética , Membro 2 da Família 12 de Carreador de Soluto/genética , Membro 2 da Família 12 de Carreador de Soluto/metabolismo , Glândulas Sudoríparas/metabolismo , Glândulas Sudoríparas/patologia
20.
Cancer Res ; 80(16): 3359-3371, 2020 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-32554750

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is a deadly and aggressive cancer. Understanding mechanisms that drive preneoplastic pancreatic lesions is necessary to improve early diagnostic and therapeutic strategies. Mutations and inactivation of activin-like kinase (ALK4) have been demonstrated to favor PDAC onset. Surprisingly, little is known regarding the ligands that drive ALK4 signaling in pancreatic cancer or how this signaling pathway limits the initiation of neoplastic lesions. In this study, data mining and histologic analyses performed on human and mouse tumor tissues revealed that activin A is the major ALK4 ligand that drives PDAC initiation. Activin A, which is absent in normal acinar cells, was strongly induced during acinar-to-ductal metaplasia (ADM), which was promoted by pancreatitis or the activation of KrasG12D in mice. Activin A expression during ADM was associated with the cellular senescence program that is induced in precursor lesions. Blocking activin A signaling through the use of a soluble form of activin receptor IIB (sActRIIB-Fc) and ALK4 knockout in mice expressing KrasG12D resulted in reduced senescence associated with decreased expression of p21, reduced phosphorylation of H2A histone family member X (H2AX), and increased proliferation. Thus, this study indicates that activin A acts as a protective senescence-associated secretory phenotype factor produced by Kras-induced senescent cells during ADM, which limits the expansion and proliferation of pancreatic neoplastic lesions. SIGNIFICANCE: This study identifies activin A to be a beneficial, senescence-secreted factor induced in pancreatic preneoplastic lesions, which limits their proliferation and ultimately slows progression into pancreatic cancers.


Assuntos
Receptores de Ativinas Tipo I/metabolismo , Ativinas/biossíntese , Carcinoma Ductal Pancreático/etiologia , Senescência Celular/fisiologia , Neoplasias Pancreáticas/etiologia , Lesões Pré-Cancerosas/etiologia , Receptores de Ativinas Tipo I/genética , Receptores de Activinas Tipo II/metabolismo , Ativinas/antagonistas & inibidores , Animais , Carcinoma Ductal Pancreático/metabolismo , Progressão da Doença , Genes ras , Humanos , Camundongos , Neoplasias Pancreáticas/metabolismo , Fosforilação , Lesões Pré-Cancerosas/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Ativação Transcricional
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