RESUMO
BACKGROUND: MicroRNAs regulate cardiac hypertrophy development, which precedes and predicts the risk of heart failure. microRNA-204-5p (miR-204) is well expressed in cardiomyocytes, but its role in developing cardiac hypertrophy and cardiac dysfunction (CH/CD) remains poorly understood. METHODS: We performed RNA-sequencing, echocardiographic, and molecular/morphometric analysis of the heart of mice lacking or overexpressing miR-204 five weeks after trans-aortic constriction (TAC). The neonatal rat cardiomyocytes, H9C2, and HEK293 cells were used to determine the mechanistic role of miR-204. RESULTS: The stretch induces miR-204 expression, and miR-204 inhibits the stretch-induced hypertrophic response of H9C2 cells. The mice lacking miR-204 displayed a higher susceptibility to CH/CD during pressure overload, which was reversed by the adeno-associated virus serotype-9-mediated cardioselective miR-204 overexpression. Bioinformatic analysis of the cardiac transcriptomics of miR-204 knockout mice following pressure overload suggested deregulation of apelin-receptor (APJ) signalling. We found that the stretch-induced extracellular signal-regulated kinase 1/2 (ERK1/2) activation and hypertrophy-related genes expression depend on the APJ, and both of these effects are subject to miR-204 levels. The dynamin inhibitor dynasore inhibited both stretch-induced APJ endocytosis and ERK1/2 activation. In contrast, the miR-204-induced APJ endocytosis was neither inhibited by dynamin inhibitors (dynasore and dyngo) nor associated with ERK1/2 activation. We find that the miR-204 increases the expression of ras-associated binding proteins (e.g., Rab5a, Rab7) that regulate cellular endocytosis. CONCLUSIONS: Our results show that miR-204 regulates trafficking of APJ and confers resistance to pressure overload-induced CH/CD, and boosting miR-204 can inhibit the development of CH/CD.
Assuntos
Receptores de Apelina/antagonistas & inibidores , Cardiomegalia/prevenção & controle , MicroRNAs/farmacologia , Animais , Receptores de Apelina/metabolismo , Cardiomegalia/tratamento farmacológico , Modelos Animais de Doenças , Cardiopatias/tratamento farmacológico , Cardiopatias/prevenção & controle , MicroRNAs/metabolismo , Ratos , Transdução de Sinais/efeitos dos fármacosRESUMO
The apelin receptor (APLNR) regulates many biological processes including metabolism, angiogenesis, circulating blood volume and cardiovascular function. Additionally, APLNR is overexpressed in various types of cancer and influences cancer progression. APLNR is reported to regulate tumor recognition during immune surveillance by modulating the IFN-γ response. However, the mechanism of APLNR cross-talk with intratumoral IFN-γ signaling remains unknown. Here, we show that activation of APLNR up-regulates IFN-γ signaling in melanoma cells through APLNR mediated ß-arrestin 1 but not ß-arrestin 2 recruitment. Our data suggests that ß-arrestin 1 directly interacts with STAT1 to inhibit STAT1 phosphorylation to attenuate IFN-γ signaling. The APLNR mutant receptor, I109A, which is deficient in ß-arrestins recruitment, is unable to enhance intratumoral IFN-γ signaling. While APLNR N112G, a constitutively active mutant receptor, increases intratumoral sensitivity to IFN-γ signaling by enhancing STAT1 phosphorylation upon IFN-γ exposure. We also demonstrate in a co-culture system that APLNR regulates tumor survival rate. Taken together, our findings reveal that APLNR modulates IFN-γ signaling in melanoma cells and suggest that APLNR may be a potential target to enhance the efficacy of immunotherapy.
Assuntos
Receptores de Apelina/fisiologia , Interferon gama/fisiologia , Janus Quinases/fisiologia , Melanoma/metabolismo , Proteínas de Neoplasias/fisiologia , Fator de Transcrição STAT1/fisiologia , Transdução de Sinais/fisiologia , beta-Arrestina 1/fisiologia , Receptores de Apelina/antagonistas & inibidores , Receptores de Apelina/química , Receptores de Apelina/genética , Linhagem Celular Tumoral , Citotoxicidade Imunológica , Células HEK293 , Humanos , Janus Quinases/antagonistas & inibidores , Melanoma/imunologia , Modelos Moleculares , Mapeamento de Interação de Proteínas , Interferência de RNA , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/farmacologia , Linfócitos T/imunologia , beta-Arrestina 2/análiseRESUMO
BACKGROUND: Apelin and its receptor angiotensin receptor - like 1 (APJ) are closely related to renal fibrosis, but their specific roles in renal fibrosis are still controversial. In this article, we discussed the role of Apelin/APJ system in renal fibrosis and its mechanism. METHODS: Chronic intermittent hypoxia (CIH) rat model was established to induce the environment of renal fibrosis and a competitive antagonist of the APJ receptor ML221 was administered to CIH rats. The rats were divided into Control, CIH and ML221 groups. HE staining was used to detect the inflammatory injury and fibrosis of renal tissue. The expressions of renal fibrosis-related indicators transforming growth factor-ß (TGF-ß), α-smooth muscle actin (α-SMA) and Human type I collagen (Col-â ) were detected by immunohistochemistry. The levels of oxidative stress indexes reactive oxygen species (ROS), Malondialdehyde (MDA), Superoxide Dismutase (SOD) and inflammation-related indexes Interleukin (IL) -6, tumor necrosis factor-α (TNF-α) and IL-1ß were detected by ELISA. At the same time, the levels of Apelin-13 and AngiotensinII (Angâ ¡) were also measured by ELISA. Finally, western blot was used to detect the expression of Apelin pathway and renal fibrosis-related proteins. In addition, at the cellular level, we divided the cells into Control, CIH, Apelin-13 and Apelin-13+ML-221 groups to further verify the specific mechanisms at the cellular level. RESULTS: The expression of Apeline-13 and its related pathways was significantly increased after the induction of CIH in rats. However, the degree of renal fibrosis in ML221 group was further significantly increased after inhibiting the expression of Apelin. At the cellular level, CIH model cells treated with Apelin-13 significantly reduced cell proliferation, oxidative stress and inflammatory response, and decreased the expression of fibrosis-related proteins, which can be reversed by ML221 administration. CONCLUSION: The increased reactivity of Apelin may be one of the protective mechanisms against renal fibrosis induced by CIH.
Assuntos
Apelina/metabolismo , Fibrose/metabolismo , Hipóxia/complicações , Nefropatias/metabolismo , Angiotensina II/metabolismo , Animais , Receptores de Apelina/antagonistas & inibidores , Linhagem Celular , Fibrose/etiologia , Fibrose/patologia , Humanos , Inflamação/etiologia , Inflamação/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Rim/efeitos dos fármacos , Rim/patologia , Nefropatias/etiologia , Nefropatias/patologia , Masculino , Nitrobenzoatos/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Piranos/farmacologia , Ratos WistarRESUMO
Apelin is an endogenous ligand of G protein-coupled receptor APJ. Apelin/APJ system is widely expressed in abundant tissues, especially bone, joint and muscle tissue. This review focus on the effects of apelin/APJ system on locomotor system. An increasing number of evidence suggests that apelin/APJ system plays a crucial role in many physiological and pathological processes of locomotor system. Physiologically, apelin/APJ system promotes bone formation, muscle metabolism and skeletal muscle production. Pathologically, apelin/APJ system exacerbates osteoarthritis pathogenesis, whereas it alleviates osteoporosis. Besides, the level of apelin expression is regulated by different training modes, including continuous aerobic exercise, high-intensity interval training and resistance exercises. More importantly, exercise-induced apelin may be a potent pharmacological agent for the treatment of diseases and the regulation of physiological processes. Considering the pleiotropic effects of apelin on locomotor system, apelin/APJ system may be an important therapeutic target for locomotor system diseases.
Assuntos
Receptores de Apelina/metabolismo , Apelina/metabolismo , Doenças Musculoesqueléticas/tratamento farmacológico , Animais , Apelina/agonistas , Apelina/antagonistas & inibidores , Receptores de Apelina/agonistas , Receptores de Apelina/antagonistas & inibidores , Modelos Animais de Doenças , Humanos , Terapia de Alvo Molecular/métodos , Doenças Musculoesqueléticas/patologia , Transdução de Sinais/efeitos dos fármacosRESUMO
This study aimed to investigate whether inhibition of endoplasmic reticulum stress (ERS) mediated the ameliorative effect of apelin on acute heart failure (AHF). Rabbit model of AHF was induced by sodium pentobarbital. Cardiac dysfunction and injury were detected in the rabbit models of AHF, including impaired hemodynamic parameters and increased levels of CK-MB and cTnI. Apelin treatment dramatically improved cardiac impairment caused by AHF. ERS, indexed by increased GRP78, CHOP, and cleaved-caspase12 protein levels, was simultaneously attenuated by apelin. Apelin also could ameliorate increased protein levels of cleaved-caspase3 and Bax, and improved decreased protein levels of Bcl-2. Two common ERS stimulators, tunicamycin (Tm) and dithiothreitol (DTT) blocked the ameliorative effect of apelin on AHF. Phosphorylated Akt levels increased after apelin treatment in the rabbit models of AHF. The Akt signaling inhibitors wortmannin and LY294002 could block the cardioprotective effect of apelin, which could be relieved by ERS inhibitor 4-phenyl butyric acid (4-PBA). The aforementioned beneficial effects of apelin could all be blocked by APJ receptor antagonist F13A. 4-PBA and SC79, an Akt activator, can restore the ameliorative effect of apelin on AHF blocked by F13A. Apelin treatment dramatically ameliorated cardiac impairment caused by AHF, which might be mediated by APJ/Akt/ERS signaling pathway. These results will shed new light on AHF therapy.
Assuntos
Apelina/uso terapêutico , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Insuficiência Cardíaca/tratamento farmacológico , Doença Aguda , Animais , Receptores de Apelina/antagonistas & inibidores , Receptores de Apelina/metabolismo , Modelos Animais de Doenças , Coração/efeitos dos fármacos , Coração/fisiopatologia , Insuficiência Cardíaca/induzido quimicamente , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/patologia , Miocárdio/metabolismo , Pentobarbital/efeitos adversos , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/metabolismo , Coelhos , Transdução de Sinais/efeitos dos fármacosRESUMO
BACKGROUND AND AIMS: Apelin (APLN) is the endogenous ligand of its G protein-coupled receptor, apelin receptor (APJ). APLN serum levels are increased in human liver diseases. We evaluated whether the APLN-APJ axis regulates ductular reaction and liver fibrosis during cholestasis. APPROACH AND RESULTS: We measured the expression of APLN and APJ and serum APLN levels in human primary sclerosing cholangitis (PSC) samples. Following bile duct ligation (BDL) or sham surgery, male wild-type (WT) mice were treated with ML221 (APJ antagonist) or saline for 1 week. WT and APLN-/- mice underwent BDL or sham surgery for 1 week. Multidrug resistance gene 2 knockout (Mdr2-/- ) mice were treated with ML221 for 1 week. APLN levels were measured in serum and cholangiocyte supernatants, and cholangiocyte proliferation/senescence and liver inflammation, fibrosis, and angiogenesis were measured in liver tissues. The regulatory mechanisms of APLN-APJ in (1) biliary damage and liver fibrosis were examined in human intrahepatic biliary epithelial cells (HIBEpiCs) treated with APLN and (2) hepatic stellate cell (HSC) activation in APLN-treated human HSC lines (HHSteCs). APLN serum levels and biliary expression of APLN and APJ increased in PSC samples. APLN levels were higher in serum and cholangiocyte supernatants from BDL and Mdr2-/- mice. ML221 treatment or APLN-/- reduced BDL-induced and Mdr2-/- -induced cholangiocyte proliferation/senescence, liver inflammation, fibrosis, and angiogenesis. In vitro, APLN induced HIBEpiC proliferation, increased nicotinamide adenine dinucleotide phosphate oxidase 4 (Nox4) expression, reactive oxygen species (ROS) generation, and extracellular signal-regulated kinase (ERK) phosphorylation. Pretreatment of HIBEpiCs with ML221, diphenyleneiodonium chloride (Nox4 inhibitor), N-acetyl-cysteine (NAC, ROS inhibitor), or PD98059 (ERK inhibitor) reduced APLN-induced cholangiocyte proliferation. Activation of HHSteCs was induced by APLN but reduced by NAC. CONCLUSIONS: The APLN-APJ axis induces cholangiocyte proliferation through Nox4/ROS/ERK-dependent signaling and HSC activation through intracellular ROS. Modulation of the APLN-APJ axis may be important for managing cholangiopathies.
Assuntos
Receptores de Apelina/metabolismo , Apelina/metabolismo , Colangite Esclerosante/metabolismo , Colestase/metabolismo , Cirrose Hepática/metabolismo , Nitrobenzoatos/farmacologia , Piranos/farmacologia , Acetilcisteína/farmacologia , Animais , Receptores de Apelina/antagonistas & inibidores , Proliferação de Células , Colangite Esclerosante/patologia , Inibidores Enzimáticos/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Flavonoides/farmacologia , Sequestradores de Radicais Livres/farmacologia , Células Estreladas do Fígado/metabolismo , Humanos , Camundongos , NADPH Oxidase 4/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
Parkinson's disease (PD) is characterized by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta. Several brain-gut peptides are able to exert neuroprotective effects on the nigrostriatal dopaminergic system. Apelin-13 is a neuropeptide, conveying potential neuroprotective activities. However, whether, and how, apelin-13 could antagonize rotenone-induced neurotoxicity has not yet been elucidated. In the present study, rotenone-treated SH-SY5Y cells and rats were used to clarify whether apelin-13 has protective effects on dopaminergic neurons, both in vivo and in vitro. The results showed that apelin-13 could protect SH-SY5Y cells from rotenone-induced injury and apoptosis. Apelin-13 was able to activate autophagy, and restore rotenone induced autophagy impairment in SH-SY5Y cells, which could be blocked by the autophagy inhibitor 3-Methyladenine. Apelin-13 activated AMPK/mTOR/ULK-1 signaling, AMPKα inhibitor compound C, as well as apelin receptor blockage via siRNA, which could block apelin-13-induced signaling activation, autophagy activation, and protective effects, in rotenone-treated SH-SY5Y cells. These results indicated that apelin-13 exerted neuroprotective properties against rotenone by stimulating AMPK/mTOR/ULK-1 signaling-mediated autophagy via the apelin receptor. We also observed that intracerebroventricular injection of apelin-13 could alleviate nigrostriatal dopaminergic neuron degeneration in rotenone-treated rats. Our findings provide new insights into the mechanism by which apelin-13 might attenuate neurotoxicity in PD.
Assuntos
Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Rotenona/toxicidade , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Receptores de Apelina/antagonistas & inibidores , Receptores de Apelina/genética , Receptores de Apelina/metabolismo , Autofagia/efeitos dos fármacos , Autofagia/fisiologia , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/metabolismo , Linhagem Celular , Neurônios Dopaminérgicos/patologia , Humanos , Masculino , Fármacos Neuroprotetores/metabolismo , Fármacos Neuroprotetores/farmacologia , Neurotoxinas/toxicidade , Transtornos Parkinsonianos/tratamento farmacológico , Transtornos Parkinsonianos/metabolismo , Transtornos Parkinsonianos/patologia , RNA Interferente Pequeno/genética , Ratos , Ratos Wistar , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismoRESUMO
Hybridoma and phage display are two powerful technologies for isolating target-specific monoclonal antibodies based on the binding. However, for complex membrane proteins, such as G protein-coupled receptors (GPCRs), binding-based screening rarely results in functional antibodies. Here we describe a function-based high-throughput screening method for quickly identifying antibody antagonists and agonists against GPCRs by combining glycosylphosphatidylinositol-anchored antibody cell display with ß-arrestin recruitment-based cell sorting and screening. This method links antibody genotype with phenotype and is applicable to all GPCR targets. We validated this method by identifying a panel of antibody antagonists and an antibody agonist to the human apelin receptor from an immune antibody repertoire. In contrast, we obtained only neutral binders and antibody antagonists from the same repertoire by phage display, suggesting that the new approach described here is more efficient than traditional methods in isolating functional antibodies. This new method may create a new paradigm in antibody drug discovery.
Assuntos
Anticorpos/farmacologia , Receptores de Apelina/agonistas , Receptores de Apelina/antagonistas & inibidores , Descoberta de Drogas , Ensaios de Triagem em Larga Escala , Animais , Receptores de Apelina/genética , Receptores de Apelina/metabolismo , Células CHO , Linhagem Celular Tumoral , Técnicas de Visualização da Superfície Celular , Cricetulus , Citometria de Fluxo , Genes Reporter , Células HEK293 , Humanos , Hibridomas , Estudo de Prova de Conceito , Transdução de Sinais , beta-Arrestinas/genética , beta-Arrestinas/metabolismoRESUMO
Apelin is an endogenous ligand of G protein-coupled receptor APJ. It is extensively expressed in many tissues such as heart, liver, and kidney, especially in lung tissue. A growing body of evidence suggests that apelin/APJ system is closely related to the development of respiratory diseases. Therefore, in this review, we focus on the role of apelin/APJ system in respiratory diseases, including pulmonary arterial hypertension (PAH), pulmonary embolism (PE), acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), obstructive sleep apnoea syndrome (OSAS), non-small cell lung cancer (NSCLC), pulmonary edema, asthma, and chronic obstructive pulmonary diseases. In detail, apelin/APJ system attenuates PAH by activating AMPK-KLF2-eNOS-NO signaling and miR424/503-FGF axis. Also, apelin protects against ALI/ARDS by reducing mitochondrial ROS-triggered oxidative damage, mitochondria apoptosis, and inflammatory responses induced by the activation of NF-κB and NLRP3 inflammasome. Apelin/APJ system also prevents the occurrence of pulmonary edema via activating AKT-NOS3-NO pathway. Moreover, apelin/APJ system accelerates NSCLC cells' proliferation and migration via triggering ERK1/2-cyclin D1 and PAK1-cofilin signaling, respectively. Additionally, apelin/APJ system may act as a predictor in the development of OSAS and PE. Considering the pleiotropic actions of apelin/APJ system, targeting apelin/APJ system may be a potent therapeutic avenue for respiratory diseases.
Assuntos
Receptores de Apelina/metabolismo , Apelina/metabolismo , Pneumopatias/patologia , Neoplasias Pulmonares/patologia , Apelina/agonistas , Apelina/antagonistas & inibidores , Receptores de Apelina/agonistas , Receptores de Apelina/antagonistas & inibidores , Humanos , Pneumopatias/metabolismo , Neoplasias Pulmonares/metabolismo , MicroRNAs/metabolismo , NF-kappa B/metabolismo , Oxirredutases/metabolismo , Proteínas Quinases/metabolismo , Transdução de SinaisRESUMO
Introduction: The apelinergic system is regarded as a novel therapeutic target for cardiovascular health, fluid homeostasis, the hypothalamic-pituitary-adrenal (HPA) axis as well as carbohydrate and fat metabolism. Two endogenous peptide ligands, namely apelin and elabela, have been demonstrated to moderate its various metabolic and neurological functions. Both bind with high (sub)-nanomolar affinity to APJR but get degraded rapidly in circulation. In addition, various diseases have been associated with the depletion of these regulatory peptides. Besides blocking the degrading proteases, a common strategy in targeting drugs to APJR is the development of metabolically stable peptide analogs or small molecule modulators. Supporting this trend, patent literature has evolved from 121 patents in 2014 to a total of almost 1000 patents today.Areas covered: This review includes WIPO-listed small molecule and peptide-based agonists, antagonists and allosteric modulators of APJR published between 2014 and 2019.Expert opinion: Both apelin peptide analogues and small molecule modulators are emerging, only recently including one example of an elabela-based analogue. Patent activity is predominantly on agonistic modulators since they show higher affinity and fewer off-target effects. Although several low nanomolar binders with half-lives exceeding 24 h have been confirmed in animal models, clinical validation of these drug-targets is sparse.
Assuntos
Receptores de Apelina/antagonistas & inibidores , Sistema Renina-Angiotensina/efeitos dos fármacos , Animais , Humanos , Patentes como Assunto , Bibliotecas de Moléculas PequenasRESUMO
The predicted protein encoded by the APJ gene discovered in 1993 was originally classified as a class A G protein-coupled orphan receptor but was subsequently paired with a novel peptide ligand, apelin-36 in 1998. Substantial research identified a family of shorter peptides activating the apelin receptor, including apelin-17, apelin-13, and [Pyr1]apelin-13, with the latter peptide predominating in human plasma and cardiovascular system. A range of pharmacological tools have been developed, including radiolabeled ligands, analogs with improved plasma stability, peptides, and small molecules including biased agonists and antagonists, leading to the recommendation that the APJ gene be renamed APLNR and encode the apelin receptor protein. Recently, a second endogenous ligand has been identified and called Elabela/Toddler, a 54-amino acid peptide originally identified in the genomes of fish and humans but misclassified as noncoding. This precursor is also able to be cleaved to shorter sequences (32, 21, and 11 amino acids), and all are able to activate the apelin receptor and are blocked by apelin receptor antagonists. This review summarizes the pharmacology of these ligands and the apelin receptor, highlights the emerging physiologic and pathophysiological roles in a number of diseases, and recommends that Elabela/Toddler is a second endogenous peptide ligand of the apelin receptor protein.
Assuntos
Receptores de Apelina/metabolismo , Hormônios Peptídicos/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia , Sequência de Aminoácidos , Animais , Apelina/metabolismo , Apelina/farmacologia , Receptores de Apelina/agonistas , Receptores de Apelina/antagonistas & inibidores , Receptores de Apelina/química , Humanos , Ligantes , Modelos Moleculares , Hormônios Peptídicos/química , Hormônios Peptídicos/farmacologia , Conformação Proteica , Transdução de Sinais/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/metabolismo , Distribuição TecidualRESUMO
Angiogenesis is a hallmark of cancer, promoting growth and metastasis. Anti-angiogenic treatment has limited efficacy due to therapy-induced blood vessel alterations, often followed by local hypoxia, tumor adaptation, progression, and metastasis. It is therefore paramount to overcome therapy-induced resistance. We show that Apelin inhibition potently remodels the tumor microenvironment, reducing angiogenesis, and effectively blunting tumor growth. Functionally, targeting Apelin improves vessel function and reduces polymorphonuclear myeloid-derived suppressor cell infiltration. Importantly, in mammary and lung cancer, Apelin prevents resistance to anti-angiogenic receptor tyrosine kinase (RTK) inhibitor therapy, reducing growth and angiogenesis in lung and breast cancer models without increased hypoxia in the tumor microenvironment. Apelin blockage also prevents RTK inhibitor-induced metastases, and high Apelin levels correlate with poor prognosis of anti-angiogenic therapy patients. These data identify a druggable anti-angiogenic drug target that reduces tumor blood vessel densities and normalizes the tumor vasculature to decrease metastases.
Assuntos
Inibidores da Angiogênese/farmacologia , Receptores de Apelina/metabolismo , Apelina/metabolismo , Movimento Celular/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Mamárias Experimentais/tratamento farmacológico , Neovascularização Patológica , Inibidores de Proteínas Quinases/farmacologia , Sunitinibe/farmacologia , Animais , Apelina/antagonistas & inibidores , Apelina/deficiência , Apelina/genética , Receptores de Apelina/antagonistas & inibidores , Receptores de Apelina/deficiência , Receptores de Apelina/genética , Linhagem Celular Tumoral , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Neoplasias Mamárias Experimentais/genética , Neoplasias Mamárias Experimentais/metabolismo , Neoplasias Mamárias Experimentais/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células-Tronco Embrionárias Murinas/efeitos dos fármacos , Células-Tronco Embrionárias Murinas/metabolismo , Células-Tronco Embrionárias Murinas/patologia , Metástase Neoplásica , Transdução de Sinais , Carga Tumoral/efeitos dos fármacos , Microambiente TumoralRESUMO
Neovascularization is the pathological driver of blinding eye diseases such as retinopathy of prematurity, proliferative diabetic retinopathy, and wet age-related macular degeneration. The loss of vision resulting from these diseases significantly impacts the productivity and quality of life of patients, and represents a substantial burden on the health care system. Current standard of care includes biologics that target vascular endothelial growth factor (VEGF), a key mediator of neovascularization. While anti-VGEF therapies have been successful, up to 30% of patients are non-responsive. Therefore, there is a need for new therapeutic targets, and small molecule inhibitors of angiogenesis to complement existing treatments. Apelin and its receptor have recently been shown to play a key role in both developmental and pathological angiogenesis in the eye. Through a cell-based high-throughput screen, we identified 4-aminoquinoline antimalarial drugs as potent selective antagonists of APJ. The prototypical 4-aminoquinoline, amodiaquine was found to be a selective, non-competitive APJ antagonist that inhibited apelin signaling in a concentration-dependent manner. Additionally, amodiaquine suppressed both apelin-and VGEF-induced endothelial tube formation. Intravitreal amodaiquine significantly reduced choroidal neovascularization (CNV) lesion volume in the laser-induced CNV mouse model, and showed no signs of ocular toxicity at the highest doses tested. This work firmly establishes APJ as a novel, chemically tractable therapeutic target for the treatment of ocular neovascularization, and that amodiaquine is a potential candidate for repurposing and further toxicological, and pharmacokinetic evaluation in the clinic.
Assuntos
Aminoquinolinas/uso terapêutico , Antimaláricos/uso terapêutico , Reposicionamento de Medicamentos , Neovascularização Retiniana/tratamento farmacológico , Aminoquinolinas/química , Aminoquinolinas/farmacocinética , Inibidores da Angiogênese/química , Inibidores da Angiogênese/farmacologia , Inibidores da Angiogênese/uso terapêutico , Animais , Antimaláricos/química , Antimaláricos/farmacocinética , Apelina/metabolismo , Receptores de Apelina/antagonistas & inibidores , Receptores de Apelina/metabolismo , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Neovascularização de Coroide/tratamento farmacológico , Neovascularização de Coroide/patologia , Modelos Animais de Doenças , Feminino , Humanos , Lasers , Camundongos , Camundongos Endogâmicos C57BL , Neovascularização Retiniana/patologia , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/uso terapêutico , Distribuição Tecidual , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
G-protein-coupled receptors (GPCRs) are recognized as the largest protein receptor superfamily, which are widely distributed in various tissues and organs. In addition, GPCRs are involved in many physiological and pathological longitudinal responses. Studies have indicated that putative receptor protein related to AT1 (APJ receptor) is an orphan GPCRs until its endogenous ligand apelin is found. Recently, Elabela, a new APJ receptor endogenous ligand was also found. Some evidence showed that the APJ receptor is distributed in the central nervous and cardiovascular systems. Moreover, the APJ receptor and its ligand are involved in many physiological functions and pathophysiological effects, making it a promising drug target for future treatment of diseases such as ischemic heart disease, hypertension, heart failure, and others. Although APJ is closely associated with many diseases, there are no drugs that can activate or inhibit APJ directly. In the current review, we try our best to summarize all agonists and antagonists targeting APJ, including peptides and small molecules. Given the role of apelin/APJ and Elabela/APJ in cardiovascular and other diseases, we believe that the combination of these agonists and antagonists with apelin and Elabela will play a corresponding role in various pathophysiological effects with further development of research.
Assuntos
Receptores de Apelina/genética , Apelina/genética , Hipertensão/tratamento farmacológico , Hormônios Peptídicos/genética , Receptores de Apelina/agonistas , Receptores de Apelina/antagonistas & inibidores , Sistema Cardiovascular/metabolismo , Sistema Cardiovascular/patologia , Sistema Nervoso Central/metabolismo , Sistema Nervoso Central/patologia , Sistemas de Liberação de Medicamentos , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/patologia , Humanos , Hipertensão/genética , Hipertensão/patologia , Ligantes , Receptores Acoplados a Proteínas G/genéticaRESUMO
Diabetic macular edema is major cause of vision loss associated with diabetic retinopathy. Breakdown of blood-retinal barrier, especially inner BRB, is an early event in pathogenesis of DR. Apelin, an endogenous ligand of APJ, mediates angiogenesis and is involved in the development of DR. The present study aimed to investigate effects and mechanism of apelin-13 in vascular permeability during DME. We verified apelin-13 was upregulated in DME patients' vitreous. High glucose incubation led to a progressive increase of apelin-13, APJ, cytoskeleton, and tight junction proteins, including VE-Cadherin, FAK, Src, ZO-1, and occludin. Apelin-13 promoted HRMEC proliferation and migration and phosphorylation of both cytoskeleton and tight junction under both normal and high glucose conditions. Besides, apelin-13 activated PI-3K/Akt and MAPK/Erk signaling pathways, including PLCγ1, p38, Akt, and Erk both in HRMEC and in C57BL/6 mice. Meanwhile, F13A performed opposite effects compared with apelin-13. In in vivo study, apelin-13 was also upregulated in retina of db/db mice. Taken together, apelin-13 increased biologic activity of HRMEC, as well as expression of both cytoskeleton and tight junction in DME via PI-3K/Akt and MAPK/Erk signaling pathways. Apelin-13 as an early promoter of vascular permeability may offer a new perspective strategy in early treatment of DR.
Assuntos
Apelina/farmacologia , Citoesqueleto/metabolismo , Retinopatia Diabética/patologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Edema Macular/patologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Junções Íntimas/metabolismo , Adulto , Idoso , Animais , Receptores de Apelina/antagonistas & inibidores , Receptores de Apelina/metabolismo , Permeabilidade Capilar/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Citoesqueleto/efeitos dos fármacos , Retinopatia Diabética/enzimologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/enzimologia , Células Epiteliais/metabolismo , Feminino , Glucose/toxicidade , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Edema Macular/enzimologia , Masculino , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Fosforilação/efeitos dos fármacos , Junções Íntimas/efeitos dos fármacos , Corpo Vítreo/efeitos dos fármacos , Corpo Vítreo/metabolismoRESUMO
Pathological retinal angiogenesis is caused by the progression of ischemic retinal diseases and can result in retinal detachment and irreversible blindness. This neovascularization is initiated from the retinal veins and their associated capillaries and involves the overgrowth of vascular endothelial cells. Since expression of the apelin receptor (APJ) is restricted to the veins and proliferative endothelial cells during physiological retinal angiogenesis, in the present study, we investigated the effect of APJ inhibition on pathological retinal angiogenesis in a mouse model of oxygen-induced retinopathy (OIR). In vitro experiments revealed that ML221, an APJ antagonist, suppressed cultured-endothelial cell proliferation in a dose-dependent manner. Intraperitoneal administration of ML221 inhibited pathological angiogenesis but enhanced the recovery of normal vessels into the ischemic regions in the retina of the OIR model mice. ML221 did not affect the expression levels of vascular endothelial growth factor (VEGF) and its receptor (VEGFR2) in the retina. APJ was highly expressed in the endothelial cells within abnormal vessels but was only detected in small amounts in morphologically normal vessels. These results suggest that APJ inhibitors selectively prevent pathological retinal angiogenesis and that the drugs targeting APJ may be new a candidate for treating ischemic retinopathy.
Assuntos
Receptores de Apelina/antagonistas & inibidores , Nitrobenzoatos/farmacologia , Piranos/farmacologia , Doenças Retinianas/prevenção & controle , Neovascularização Retiniana/prevenção & controle , Animais , Apelina/genética , Apelina/metabolismo , Receptores de Apelina/genética , Receptores de Apelina/metabolismo , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Modelos Animais de Doenças , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Expressão Gênica/efeitos dos fármacos , Isquemia/genética , Isquemia/metabolismo , Isquemia/prevenção & controle , Camundongos , Doenças Retinianas/genética , Doenças Retinianas/metabolismo , Neovascularização Retiniana/genética , Neovascularização Retiniana/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genética , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismoRESUMO
KEY POINTS: Dysfunctions in CNS regulation of arterial blood pressure lead to an increase in sympathetic nerve activity that participates in the pathogenesis of hypertension. The apelin-apelin receptor system affects arterial blood pressure homeostasis; however, the central mechanisms underlying apelin-mediated changes in sympathetic nerve activity and blood pressure have not been clarified. We explored the mechanisms involved in the regulation of [Pyr1 ]apelin-13-mediated cardiovascular control within the rostral ventrolateral medulla (RVLM) using selective receptor antagonists. We show that [Pyr1 ]apelin-13 acts as a modulating neurotransmitter in the normotensive RVLM to affect vascular tone through interaction with the vasopressin V1a receptor but that [Pyr1 ]apelin-13-induced sympathoexcitation is independent of angiotensin II receptor type 1, oxytocin, ionotropic glutamate and GABAA receptors. Our data confirm a role for the apelin peptide system in cardiovascular regulation at the level of the RVLM and highlight that this system is a possible potential therapeutic target for the treatment of hypertension. ABSTRACT: Apelin is a ubiquitous peptide that can elevate arterial blood pressure (ABP) yet understanding of the mechanisms involved remain incomplete. Bilateral microinjection of [Pyr1 ]apelin-13 into the rostral ventrolateral medulla (RVLM), a major source of sympathoexcitatory neurones, increases ABP and sympathetic nerve activity. We aimed to investigate the potential involvement of neurotransmitter systems through which the apelin pressor response may occur within the RVLM. Adult male Wistar rats were anaesthetized and ABP was monitored via a femoral arterial catheter. Bilateral RVLM microinjection of [Pyr1 ]apelin-13 significantly increased ABP (9 ± 1 mmHg) compared to saline (-1 ± 2mmHg; P < 0.001), which was blocked by pretreatment with the apelin receptor antagonist, F13A (0 ± 1 mmHg; P < 0.01). The rise in ABP was associated with an increase in the low frequency spectra of systolic BP (13.9 ± 4.3% total power; P < 0.001), indicative of sympathetic vasomotor activation. The [Pyr1 ]apelin-13-mediated pressor response and the increased low frequency spectra of systolic BP response were fully maintained despite RVLM pretreatment with the angiotensin II type 1 receptor antagonist losartan, the oxytocin receptor antagonist desGly-NH2 , d(CH2 )5 [D-Tyr2 ,Thr4 ]OVT, the ionotropic glutamate receptor antagonist kynurenate or the GABAA antagonist bicuculline (P > 0.05). By contrast, the [Pyr1 ]apelin-13 induced pressor and sympathoexcitatory effects were abolished by pretreatment of the RVLM with the vasopressin V1a receptor antagonist, SR 49059 (-1 ± 1 mmHg; 1.1 ± 1.1% total power, respectively; P < 0.001). These findings suggest that the pressor action of [Pyr1 ]apelin-13 in the RVLM of normotensive rats is not mediated via angiotensin II type 1 receptor, oxytocin, ionotropic glutamate or GABAA receptors but instead involves a close relationship with the neuropeptide modulator vasopressin.
Assuntos
Hipertensão/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Bulbo/metabolismo , Receptores de Vasopressinas/metabolismo , Animais , Antagonistas dos Receptores de Hormônios Antidiuréticos/farmacologia , Receptores de Apelina/antagonistas & inibidores , Pressão Sanguínea/efeitos dos fármacos , Hipertensão/fisiopatologia , Masculino , Bulbo/fisiologia , Ratos , Ratos WistarRESUMO
The apelin/apelin receptor system is widely distributed and has a dominant role in cardiovascular homeostasis and disease. The apelin gene is X-linked and is synthesized as a 77 amino acid pre-pro-peptide that is subsequently cleaved to generate a family of apelin peptides that possess similar functions but display different tissue distribution, potency and receptor binding affinity. Loss-of-function experiments using the apelin and the apelin receptor knockout mice and gain-of-function experiments using apelin peptides have delineated a well-defined role of the apelin axis in cardiovascular physiology and diseases. Activation of the apelin receptor by its cognate peptide ligand, apelin, induces a wide range of physiological effects, including vasodilation, increased myocardial contractility, angiogenesis, and balanced energy metabolism and fluid homeostasis. The apelin/apelin receptor pathway is also implicated in atherosclerosis, hypertension, coronary artery disease, heart failure, diabetes and obesity, making it a promising therapeutic target. Hence, research is expanding to develop novel therapies that inhibit degradation of endogenous apelin peptides or their analogues. Chemical synthesis of stable apelin receptor agonists aims to more efficiently enhance the activation of the apelin system. Targeting the apelin/apelin receptor axis has emerged as a novel therapeutic approach against cardiovascular diseases and an increased understanding of cardiovascular actions of the apelin system will help to develop effective interventions.
Assuntos
Receptores de Apelina , Apelina , Doenças Cardiovasculares , Transdução de Sinais , Animais , Apelina/agonistas , Apelina/antagonistas & inibidores , Apelina/genética , Apelina/metabolismo , Receptores de Apelina/agonistas , Receptores de Apelina/antagonistas & inibidores , Receptores de Apelina/genética , Receptores de Apelina/metabolismo , Doenças Cardiovasculares/tratamento farmacológico , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/metabolismo , Doenças Cardiovasculares/patologia , Metabolismo Energético , Humanos , Camundongos , Camundongos Knockout , Contração Miocárdica , Neovascularização FisiológicaRESUMO
The G-protein-coupled receptor APJ and its endogenous ligand apelin are widely expressed in many peripheral tissues and central nervous system, including adipose tissue, skeletal muscles and hypothalamus. Apelin/APJ system, involved in numerous physiological functions like angiogenesis, fluid homeostasis and energy metabolism regulation, is notably implicated in the development of different pathologies such as diabetes and its complications. Increasing evidence suggests that apelin regulates insulin sensitivity, stimulates glucose utilization and enhances brown adipogenesis in different tissues associated with diabetes. Moreover, apelin is also involved in the regulation of diabetic complications via binding to APJ receptor. Apelin improves diabetes-induced kidney hypertrophia, normalizes obesity-associated cardiac hypertrophy and negatively promotes retinal angiogenesis in diabetic retinopathy. In this review, we provide a comprehensive overview about the role of apelin/APJ system in different tissues related with diabetes. Furthermore, we describe the pathogenesis of diabetic complications associated with apelin/APJ system. Finally, agonists and antagonists targeted to APJ receptor are described in the literature. Thus, we highlight apelin/APJ system as a novel therapeutic target for pharmacological intervention in treating diabetes and its complications.