Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 430
Filtrar
1.
Int J Mol Sci ; 22(17)2021 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-34502044

RESUMO

Implantation consists of a complex process based on coordinated crosstalk between the endometrium and trophoblast. Furthermore, it is known that the microenvironment of this fetal-maternal interface plays an important role in the development of extravillous trophoblast cells. This is mainly due to the fact that tissues mediate embryonic signaling biologicals, among other molecules, prostaglandins. Prostaglandins influence tissue through several cell processes including differentiation, proliferation, and promotion of maternal immune tolerance. The aim of this study is to investigate the potential pathological mechanism of the prostaglandin E2 receptor 4 (EP4) in modulating extravillous trophoblast cells (EVTs) in unexplained recurrent marriage (uRM). Our results indicated that the expression of EP4 in EVTs was decreased in women experiencing uRM. Furthermore, silencing of EP4 showed an inhibition of the proliferation and induced apoptosis in vitro. In addition, our results demonstrated reductions in ß- human chorionic gonadotropin (hCG), progesterone, and interleukin (IL)-6, which is likely a result from the activation of the cyclic adenosine monophosphate (cAMP)- cAMP-dependent protein kinase A (PKA)-phosphorylating CREB (pCREB) pathway. Our data might provide insight into the mechanisms of EP4 linked to trophoblast function. These findings help build a more comprehensive understanding of the effects of EP4 on the trophoblast at the fetal-maternal interface in the first trimester of pregnancy.


Assuntos
Aborto Habitual/metabolismo , AMP Cíclico/metabolismo , Receptores de Prostaglandina E Subtipo EP4/metabolismo , Transdução de Sinais , Trofoblastos/metabolismo , Aborto Habitual/patologia , Adulto , Apoptose , Linhagem Celular , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Feminino , Gonadotropinas/metabolismo , Humanos , Interleucina-6/metabolismo , Pessoa de Meia-Idade , Gravidez , Progesterona/metabolismo
2.
Anticancer Res ; 41(9): 4333-4341, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34475053

RESUMO

BACKGROUND/AIM: Prostaglandin (PG) E2 mediates malignant aggressiveness by binding to four specific E-type prostanoid receptors (EP1R - 4R). This study aimed to clarify the pathological significance of EPRs in hormone-sensitive prostate cancer (HSPC) and castration-resistant prostate cancer (CRPC). MATERIALS AND METHODS: EP1R - 4R expression was examined in 102 HSPC and 27 CRPC specimens. The relationships between their expression and proliferation index (PI), apoptotic index (AI), and vascular endothelial growth factor (VEGF)-A expression were analyzed. RESULTS: EP4R expression in CRPC was significantly higher compared to that in HSPC, even in advanced disease (T3/4, N1, and/or M1). EP4R expression was significantly correlated with PI, AI, and VEGF-A expression in CRPC. Such significant relationships were not detected between EP1R - 3R and CRPC. CONCLUSION: EP4R expression in CRPC was significantly higher than that in HSPC and was associated with cancer cell proliferation, apoptosis, and pro-angiogenetic potential.


Assuntos
Neoplasias de Próstata Resistentes à Castração/patologia , Receptores de Prostaglandina E Subtipo EP4/metabolismo , Regulação para Cima , Fator A de Crescimento do Endotélio Vascular/metabolismo , Apoptose , Proliferação de Células , Sobrevivência Celular , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Gradação de Tumores , Estadiamento de Neoplasias , Neoplasias de Próstata Resistentes à Castração/metabolismo
3.
Life Sci ; 284: 119869, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34358552

RESUMO

AIMS: Investigate the involvement of Hydrogen sulfide (H2S) in inflammatory parameters and intestinal morphology caused by cholera toxin (CT) in mice. MAIN METHODS: Mice were subjected to the procedure of inducing diarrhea by CT in the isolated intestinal loop model. The intestinal loops were inoculated with H2S donor molecules (NaHS and GYY 4137) or saline and CT. To study the role of EP2 and EP4 prostaglandin E2 (PGE2) receptors in the H2S antisecretory effect, PAG (DL-propargylglycine - inhibitor of cystathionine-γ-lyase (CSE)), PF-04418948 (EP2 antagonist) and ONO-AE3-208 (EP4 antagonist) were used. The intestinal loops were evaluated for intestinal secretion, relation of the depth of villi and intestinal crypts, and real-time PCR for the mRNA of the CXCL2, IL-6, NOS-2, IL-17, NF-κB1, NF-κBIA, SLC6A4 and IFN-γ genes. KEY FINDINGS: H2S restored the villus/crypt depth ratio caused by CT. NaHS and GYY 4137 increased the expression of NF-κB1 and for the NF-κBIA gene, only GYY 4137 increased the expression of this gene. The increased expression of NF-κB inhibitors, NF-κB1 and NF-κBIA by H2S indicates a possible decrease in NF-κB activity. The pretreatment with PAG reversed the protective effect of PF-04418948 and ONO-AE3-208, indicating that H2S probably decreases PGE2 because in the presence of antagonists of this pathway, PAG promotes intestinal secretion. SIGNIFICANCE: Our results point to a protective activity of H2S against CT for promoting a protection of villus and crypt intestine morphology and also that its mechanism occurs at least in part due to decreasing the activity of NF-κB and PGE2.


Assuntos
Diarreia/induzido quimicamente , Diarreia/metabolismo , Dinoprostona/metabolismo , Sulfeto de Hidrogênio/farmacologia , Mucosa Intestinal/patologia , NF-kappa B/metabolismo , Animais , Toxina da Cólera , Feminino , Perfilação da Expressão Gênica , Masculino , Camundongos , Morfolinas/farmacologia , Compostos Organotiofosforados/farmacologia , Receptores de Prostaglandina E Subtipo EP2/metabolismo , Receptores de Prostaglandina E Subtipo EP4/metabolismo
4.
Nat Cell Biol ; 23(7): 796-807, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34239062

RESUMO

Inflammatory bowel diseases present with elevated levels of intestinal epithelial cell (IEC) death, which compromises the gut barrier, activating immune cells and triggering more IEC death. The endogenous signals that prevent IEC death and break this vicious cycle, allowing resolution of intestinal inflammation, remain largely unknown. Here we show that prostaglandin E2 signalling via the E-type prostanoid receptor 4 (EP4) on IECs represses epithelial necroptosis and induces resolution of colitis. We found that EP4 expression correlates with an improved IBD outcome and that EP4 activation induces a transcriptional signature consistent with resolution of intestinal inflammation. We further show that dysregulated necroptosis prevents resolution, and EP4 agonism suppresses necroptosis in human and mouse IECs. Mechanistically, EP4 signalling on IECs converges on receptor-interacting protein kinase 1 to suppress tumour necrosis factor-induced activation and membrane translocation of the necroptosis effector mixed-lineage kinase domain-like pseudokinase. In summary, our study indicates that EP4 promotes the resolution of colitis by suppressing IEC necroptosis.


Assuntos
Colite/metabolismo , Colo/metabolismo , Dinoprostona/metabolismo , Células Epiteliais/metabolismo , Mucosa Intestinal/metabolismo , Necroptose , Receptores de Prostaglandina E Subtipo EP4/metabolismo , Animais , Anti-Inflamatórios/farmacologia , Colite/induzido quimicamente , Colite/patologia , Colite/prevenção & controle , Colo/efeitos dos fármacos , Colo/patologia , Sulfato de Dextrana , Modelos Animais de Doenças , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/patologia , Células HT29 , Humanos , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/patologia , MAP Quinase Quinase Quinases/genética , MAP Quinase Quinase Quinases/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Necroptose/efeitos dos fármacos , Organoides , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores/genética , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Receptores de Prostaglandina E Subtipo EP4/agonistas , Receptores de Prostaglandina E Subtipo EP4/genética , Transdução de Sinais
5.
BMC Cancer ; 21(1): 493, 2021 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-33941107

RESUMO

BACKGROUND: Glioblastoma (GBM) is the deadliest and the most common primary brain tumor in adults. The invasiveness and proliferation of GBM cells can be decreased through the inhibition of Wnt/ß-catenin pathway. In this regard, celecoxib is a promising agent, but other COXIBs and 2,5-dimethylcelecoxib (2,5-DMC) await elucidation. Thus, the aim of this study was to analyze the impact of celecoxib, 2,5-DMC, etori-, rofe-, and valdecoxib on GBM cell viability and the activity of Wnt/ß-catenin pathway. In addition, the combination of the compounds with temozolomide (TMZ) was also evaluated. Cell cycle distribution and apoptosis, MGMT methylation level, COX-2 and PGE2 EP4 protein levels were also determined in order to better understand the molecular mechanisms exerted by these compounds and to find out which of them can serve best in GBM therapy. METHODS: Celecoxib, 2,5-DMC, etori-, rofe- and valdecoxib were evaluated using three commercially available and two patient-derived GBM cell lines. Cell viability was analyzed using MTT assay, whereas alterations in MGMT methylation level were determined using MS-HRM method. The impact of COXIBs, in the presence and absence of TMZ, on Wnt pathway was measured on the basis of the expression of ß-catenin target genes. Cell cycle distribution and apoptosis analysis were performed using flow cytometry. COX-2 and PGE2 EP4 receptor expression were evaluated using Western blot analysis. RESULTS: Wnt/ß-catenin pathway was attenuated by COXIBs and 2,5-DMC irrespective of the COX-2 expression profile of the treated cells, their MGMT methylation status, or radio/chemoresistance. Celecoxib and 2,5-DMC were the most cytotoxic. Cell cycle distribution was altered, and apoptosis was induced after the treatment with celecoxib, 2,5-DMC, etori- and valdecoxib in T98G cell line. COXIBs and 2,5-DMC did not influence MGMT methylation status, but inhibited COX-2/PGE2/EP4 pathway. CONCLUSIONS: Not only celecoxib, but also 2,5-DMC, etori-, rofe- and valdecoxib should be further investigated as potential good anti-GBM therapeutics.


Assuntos
Neoplasias Encefálicas/metabolismo , Inibidores de Ciclo-Oxigenase 2/farmacologia , Glioblastoma/metabolismo , Proteínas de Neoplasias/efeitos dos fármacos , Pirazóis/farmacologia , Sulfonamidas/farmacologia , Via de Sinalização Wnt/efeitos dos fármacos , Idoso , Antineoplásicos Alquilantes/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias Encefálicas/tratamento farmacológico , Celecoxib/farmacologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Ciclo-Oxigenase 2/metabolismo , Metilases de Modificação do DNA/efeitos dos fármacos , Metilases de Modificação do DNA/metabolismo , Enzimas Reparadoras do DNA/efeitos dos fármacos , Enzimas Reparadoras do DNA/metabolismo , Dinoprostona/metabolismo , Relação Dose-Resposta a Droga , Etoricoxib/farmacologia , Feminino , Glioblastoma/tratamento farmacológico , Humanos , Isoxazóis/farmacologia , Lactonas/farmacologia , Masculino , Metilação , Pessoa de Meia-Idade , Proteínas de Neoplasias/metabolismo , Receptores de Prostaglandina E Subtipo EP4/efeitos dos fármacos , Receptores de Prostaglandina E Subtipo EP4/metabolismo , Sulfonas/farmacologia , Temozolomida/farmacologia , Proteínas Supressoras de Tumor/efeitos dos fármacos , Proteínas Supressoras de Tumor/metabolismo , beta Catenina/efeitos dos fármacos , beta Catenina/metabolismo
6.
Yakugaku Zasshi ; 141(4): 473-479, 2021.
Artigo em Japonês | MEDLINE | ID: mdl-33790113

RESUMO

Prostanoids [prostaglandins (PGs) and thromboxanes (TXs)] are a series of bioactive lipid metabolites that function in an autacoid manner via activation of cognate G protein-coupled receptors (GPCRs). The nine subtypes of prostanoid receptors (DP1, DP2, EP1, EP2, EP3, EP4, FP, IP, TP) are involved in a wide range of functions, including inflammation, immune response, reproduction, and homeostasis of the intestinal mucosa and cardiovascular system. Among the prostanoid receptors, the structure of antagonist-bound DP2, which belongs to the chemoattractant receptor family, was previously determined. However, the mechanisms of prostanoid recognition and receptor activation remained elusive. To address this issue, we determined the crystal structures of antagonist-bound EP4 and PGE2-bound EP3. The EP3-PGE2 complex exhibits an active-like conformation, including outward movement of the cytoplasmic end of transmembrane (TM) 6 relative to the cytoplasmic end of TM6 of the EP4 complex. The carboxyl moiety of PGE2 is recognized through three hydrogen bonds formed by highly conserved residues: Y1142.65, T206Extracelluar loop 2 (ECL2), and R3337.40 (superscripts denote Ballesteros-Weinstein numbering). In addition, the ω-chain of PGE2 orients toward TM6, which appears to contribute to receptor activation. The structure reveals important insights into the activation mechanism of prostanoid receptors and provides a molecular basis for the binding modes of endogenous ligands. These findings should facilitate the development of subtype-selective and non-PG-like ligands.


Assuntos
Receptores de Prostaglandina/química , Receptores de Prostaglandina/metabolismo , Cristalografia por Raios X , Dinoprostona/química , Dinoprostona/metabolismo , Ligantes , Conformação Molecular , Ligação Proteica , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Prostaglandina/fisiologia , Receptores de Prostaglandina E Subtipo EP3/química , Receptores de Prostaglandina E Subtipo EP3/metabolismo , Receptores de Prostaglandina E Subtipo EP4/química , Receptores de Prostaglandina E Subtipo EP4/metabolismo
7.
Am J Physiol Heart Circ Physiol ; 320(6): H2169-H2184, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33861147

RESUMO

The small lipid-derived paracrine signaling molecules known as prostaglandins have been recognized for their ability to modulate many facets of cardiovascular physiology since their initial discovery more than 85 years ago. Although the role of prostaglandins in the vasculature has gained significant attention across time, a handful of historical studies have also directly implicated the cardiomyocyte in both prostaglandin synthesis and release. Recently, our understanding of how prostaglandin receptor modulation impacts and contributes to myocardial structure and function has gained attention while leaving most other components of myocardial prostaglandin metabolism and signaling unexplored. This mini-review highlights both the key historical studies that underpin modern prostaglandin research in the heart, while concurrently presenting the latest findings related to how prostaglandin metabolism and signaling impact myocardial injury and repair.


Assuntos
Isquemia Miocárdica/metabolismo , Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , Prostaglandinas/metabolismo , Receptores de Prostaglandina E Subtipo EP3/metabolismo , Receptores de Prostaglandina E Subtipo EP4/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Eicosanoides/metabolismo , Fibroblastos/metabolismo , Humanos , Lipoxigenase/metabolismo , Comunicação Parácrina , Prostaglandina-Endoperóxido Sintases/metabolismo , Receptores de Prostaglandina/metabolismo , Regeneração
8.
Biochem Biophys Res Commun ; 548: 196-203, 2021 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-33647796

RESUMO

BACKGROUND: Cardiac fatty acid metabolism is essential for maintaining normal cardiac function at baseline and in response to various disease stress, like diabetes. EP4 is widely expressed in cardiomyocytes and has been demonstrated to play a role in cardio function. However, its function in regulating cardiac fatty acid metabolism is remained unknown. METHODS: Mice were fed with standard chow or high-fat for eight weeks. The effects of EP4 deficiency on cardiac function, cardiomyocytes hypertrophy and myocardial fibrosis were studied. The possible regulatory mechanisms were further investigated. RESULTS: EP4-/- mice exhibited concentric hypertrophy and myocardial fibrosis with cardiac energy deprivation due to reduction of fatty acid uptake and inhibition of ATP generation mediated by FOXO1/CD36 signalling. Moreover, pharmacologically activated EP4 alleviated impaired fatty acid transport and insufficient ATP generation in cardiomyocytes. CONCLUSION: EP4 tightly coordinates the rates of cardiac fatty acid uptake and ATP generation via FOXO1/CD36 signalling axis. Our study provides evidences for the link between EP4 and cardiac fatty acid transport and further pointed out that EP4 could be a potential target for modulating fatty acid metabolism and curbing cardiac tissue-specific impairment of function following diabetes.


Assuntos
Antígenos CD36/metabolismo , Cardiomiopatias Diabéticas/prevenção & controle , Ácidos Graxos/metabolismo , Proteína Forkhead Box O1/metabolismo , Miocárdio/metabolismo , Receptores de Prostaglandina E Subtipo EP4/metabolismo , Transdução de Sinais , Trifosfato de Adenosina/metabolismo , Animais , Cardiomegalia/complicações , Cardiomegalia/patologia , Cardiomiopatias Diabéticas/complicações , Dieta Hiperlipídica , Comportamento Alimentar , Fibrose , Metabolismo dos Lipídeos , Masculino , Camundongos , Miocárdio/patologia , Receptores de Prostaglandina E Subtipo EP4/deficiência
9.
Structure ; 29(3): 200-202, 2021 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-33667375

RESUMO

In this issue of Structure, Nojima et al. (2021) report the structure of the PGE2-EP4-Gs complex by cryo-electron microscopy. This work shows unique modes of ligand binding, transduction mechanism, and G protein coupling of EP4, and serves as a starting point for development of more selective drugs.


Assuntos
Aspirina , AMP Cíclico , Microscopia Crioeletrônica , Proteínas de Ligação ao GTP , Receptores de Prostaglandina E Subtipo EP4/metabolismo
10.
Mol Cell Endocrinol ; 526: 111219, 2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33610642

RESUMO

Prostaglandin E2 (PGE2) is a principal lipid mediator mediating various biological processes including immune responses and fluid secretion. As the first line of host defense against infection, vaginal epithelium plays orchestrated roles in vaginal innate immunity. However, the effect of PGE2 triggered by pro-inflammatory stimuli on vaginal epithelium remains elusive. This study aimed to investigate the regulatory role of PGE2 on vaginal epithelium after lipopolysaccharide (LPS) stimulation. RT-PCR and western blot analysis revealed that E-prostanoid (EP) receptors EP2 and EP4 were expressed in rat vagina. Basolateral application of PGE2 induced anion secretion mediated by cystic fibrosis transmembrane conductance regulator (CFTR) via EP-adenylate cyclase-cAMP signaling pathway in rat vaginal epithelial cells. The in vivo study showed that PGE2 promoted fluid secretion in rat vagina. Moreover, LPS stimulation facilitated cyclooxygenase-dependent PGE2 synthesis and vaginal fluid secretion in vivo. Conclusively, LPS stimulation triggered epithelium-derived PGE2 production in vaginal epithelium, leading to CFTR-mediated anion secretion and luminal flushing. This study provides valuable insights into the physiological role of PGE2 during vaginal bacterial infection.


Assuntos
Líquidos Corporais/metabolismo , Dinoprostona/farmacologia , Epitélio/metabolismo , Lipopolissacarídeos/farmacologia , Vagina/metabolismo , Animais , Ânions , Líquidos Corporais/efeitos dos fármacos , AMP Cíclico/metabolismo , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Fenômenos Eletrofisiológicos/efeitos dos fármacos , Epitélio/efeitos dos fármacos , Feminino , Modelos Biológicos , Ratos Sprague-Dawley , Receptores de Prostaglandina E Subtipo EP2/metabolismo , Receptores de Prostaglandina E Subtipo EP4/metabolismo , Transdução de Sinais/efeitos dos fármacos , Membro 2 da Família 12 de Carreador de Soluto/metabolismo , Vagina/efeitos dos fármacos
11.
Exp Eye Res ; 205: 108507, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33609510

RESUMO

Proliferative retinopathies, such as proliferative diabetic retinopathy (PDR) and retinopathy of prematurity (ROP) are major causes of visual impairment and blindness in industrialized countries. Prostaglandin E2 (PGE2) is implicated in cellular proliferation and migration via E-prostanoid receptor (EP4R). The aim of this study was to investigate the role of PGE2/EP4R signaling in the promotion of retinal neovascularisation. In a streptozotocin (STZ)-induced diabetic model and an oxygen-induced retinopathy (OIR) model, rats received an intravitreal injection of PGE2, cay10598 (an EP4R agonist) or AH23848 (an EP4R antagonist). Optical coherence tomography, retinal histology and biochemical markers were assessed. Treatment with PGE2 or cay10598 accelerated pathological retinal angiogenesis in STZ and OIR-induced rat retina, which was ameliorated in rats pretreated with AH23848. Serum VEGF-A was upregulated in the PGE2-treated diabetic rats vs non-treated diabetic rats and significantly downregulated in AH23848-treated diabetic rats. PGE2 or cay10598 treatment also significantly accelerated endothelial tip-cell formation in new-born rat retina. In addition, AH23848 treatment attenuated PGE2-or cay10598-induced proliferation and migration by repressing the EGF receptor (EGFR)/Growth factor receptor bound protein 2-associated binder protein 1 (Gab1)/Akt/NF-κB/VEGF-A signaling network in human retinal microvascular endothelial cells (hRMECs). PGE2/EP4R signaling network is thus a potential therapeutic target for pathological intraocular angiogenesis.


Assuntos
Dinoprostona/fisiologia , Receptores ErbB/metabolismo , Fosfoproteínas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores de Prostaglandina E Subtipo EP4/metabolismo , Neovascularização Retiniana/fisiopatologia , Animais , Animais Recém-Nascidos , Compostos de Bifenilo/farmacologia , Western Blotting , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Diabetes Mellitus Experimental , Modelos Animais de Doenças , Ensaio de Desvio de Mobilidade Eletroforética , Endotélio Vascular/metabolismo , Injeções Intravítreas , Masculino , NF-kappa B/metabolismo , Oxigênio/toxicidade , Fosforilação , Pirrolidinonas/farmacologia , Ratos Sprague-Dawley , Receptores de Prostaglandina E Subtipo EP4/agonistas , Receptores de Prostaglandina E Subtipo EP4/antagonistas & inibidores , Neovascularização Retiniana/metabolismo , Vasos Retinianos/metabolismo , Transdução de Sinais/fisiologia , Tetrazóis/farmacologia , Fator A de Crescimento do Endotélio Vascular/metabolismo
12.
J Physiol Sci ; 71(1): 8, 2021 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-33622238

RESUMO

Colonic motor activity is important for the formation and propulsion of feces. The production of prostaglandins (PGs) in colonic tissue is considered to play a critical role in the generation and regulation of colonic motility. In this study, we investigated the inhibitory effects of PGE2 and selective agonists of four EP receptors on the spontaneous phasic contractions, called 'giant contractions' (GCs), of mucosa-free circular smooth muscle strips from the rat middle colon. Neural blockade with tetrodotoxin (TTX) increased the frequency and amplitude of the GCs by about twofold. However, inhibiting PG production with piroxicam reduced the GC frequency in the presence of TTX, but did not affect the GC amplitude. In the presence of both TTX and piroxicam, exogenous PGE2 and each EP receptor agonist were cumulatively added to the tissue bath. In this setting, PGE2, the EP2 agonist ONO-AE1-259, and the EP4 agonist ONO-AE1-329, but not the EP1 agonist ONO-AE-DI-004 or the EP3 agonist ONO-AE-248, concentration-dependently reduced the GC frequency and amplitude. The PGE2-induced inhibition of GC frequency and amplitude was inhibited by the EP4 antagonist ONO-AE3-208, but not by the EP1/2 antagonist AH6809. Immunohistochemistry revealed the EP2 and EP4 receptors were localized in perinuclear sites in circular smooth muscle cells. EP2 immunoreactivity was also located in GFAP-immunoreactive enteroglia, whereas EP4 immunoreactivity was also located in HU (embryonic lethal, abnormal vision [ELAV] protein; a marker of all myenteric neurons)-immunoreactive myenteric nerve cell bodies. These results suggest that the PGs produced in the colonic tissue inhibit the GC frequency and amplitude of circular muscle in the rat middle colon, and is mediated by EP4 receptors expressed in the smooth muscle cells.


Assuntos
Colo/efeitos dos fármacos , Dinoprostona/farmacologia , Motilidade Gastrointestinal/fisiologia , Músculo Liso/efeitos dos fármacos , Piroxicam/farmacologia , Receptores de Prostaglandina E Subtipo EP4/metabolismo , Animais , Carbacol/farmacologia , Agonistas Colinérgicos/farmacologia , Colo/fisiologia , Imuno-Histoquímica , Masculino , Ratos , Ratos Wistar , Receptores de Prostaglandina E Subtipo EP1 , Receptores de Prostaglandina E Subtipo EP2/agonistas , Receptores de Prostaglandina E Subtipo EP2/antagonistas & inibidores , Receptores de Prostaglandina E Subtipo EP2/metabolismo , Receptores de Prostaglandina E Subtipo EP3 , Receptores de Prostaglandina E Subtipo EP4/agonistas , Receptores de Prostaglandina E Subtipo EP4/antagonistas & inibidores , Bloqueadores dos Canais de Sódio/farmacologia , Tetrodotoxina/farmacologia , Proteínas de Peixe-Zebra
13.
PLoS One ; 16(1): e0245400, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33444342

RESUMO

The Na+/K+ ATPase is a key regulator of the hepatocytes ionic homeostasis, which when altered may lead to many liver disorders. We demonstrated recently, a significant stimulation of the Na+/K+ ATPase in HepG2 cells treated with the S1P analogue FTY 720P, that was mediated through PGE2. The mechanism by which the prostaglandin exerts its effect was not investigated, and is the focus of this work. The type of receptors involved was determined using pharmacological inhibitors, while western blot analysis, fluorescence imaging of GFP-tagged Na+/K+ ATPase, and time-lapse imaging on live cells were used to detect changes in membrane abundance of the Na+/K+ ATPase. The activity of the ATPase was assayed by measuring the amount of inorganic phosphate liberated in the presence and absence of ouabain. The enhanced activity of the ATPase was not observed when EP4 receptors were blocked but still appeared in presence inhibitors of EP1, EP2 and EP3 receptors. The involvement of EP4 was confirmed by the stimulation observed with EP4 agonist. The stimulatory effect of PGE2 did not appear in presence of Rp-cAMP, an inhibitor of PKA, and was imitated by db-cAMP, a PKA activator. Chelating intracellular calcium with BAPTA-AM abrogated the effect of db-cAMP as well as that of PGE2, but PGE2 treatment in a calcium-free PBS medium did not, suggesting an involvement of intracellular calcium, that was confirmed by the results obtained with 2-APB treatment. Live cell imaging showed movement of GFP-Na+/K+ ATPase-positive vesicles to the membrane and increased abundance of the ATPase at the membrane after PGE2 treatment. It was concluded that PGE2 acts via EP4, PKA, and intracellular calcium.


Assuntos
Cálcio/metabolismo , Carcinoma Hepatocelular/patologia , Dinoprostona/farmacologia , Neoplasias Hepáticas/patologia , Receptores de Prostaglandina E Subtipo EP4/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/metabolismo , Células Hep G2 , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/metabolismo , Ocitócicos/farmacologia , Proteína Quinase C/metabolismo , Receptores de Prostaglandina E Subtipo EP4/genética , Transdução de Sinais , ATPase Trocadora de Sódio-Potássio/genética
14.
Theranostics ; 11(6): 2742-2754, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33456570

RESUMO

Aim: Immune responsive 12/15 lipoxygenase (12/15LOX)-orchestrate biosynthesis of essential inflammation-resolution mediators during acute inflammatory response in post-myocardial infarction (MI). Lack of 12/15LOX dampens proinflammatory mediator 12-(S)-hydroxyeicosatetraenoic acid (12-(S)-HETE), improves post-MI survival, through the biosynthesis of endogenous mediators epoxyeicosatrienoic acids (EETs; cypoxins) to resolve post-MI inflammation. However, the mechanism that amplifies cypoxins-directed cardiac repair in acute heart failure (AHF) and chronic HF (CHF) remains of interest in MI-directed renal inflammation. Therefore, we determined the role of EETs in macrophage-specific receptor activation in facilitating cardiac repair in 12/15LOX deficient mice experiencing HF. Methods and Results: Risk-free young adult (8 -12 week-old) male C57BL/6J wild-type mice (WT; n = 43) and 12/15LOX-/- mice (n = 31) were subjected to permanent coronary artery ligation and monitored at day (d)1, d5 (as acute HF), and d28 to d56 (8 weeks; chronic HF) post-surgery maintaining no-MI mice that served as d0 naïve controls. Left ventricle (LV) infarcted area of 12/15LOX-/- mice displayed an increase in expression of prostanoid receptor EP4 along with monocyte chemoattractant protein-1 CCL2 in AHF and CHF. The transcriptome analysis of isolated leukocytes (macrophages/neutrophils) from infarcted LV revealed a higher expression of EP4 on reparative macrophages expressing MRC-1 in 12/15LOX-/- mice. Deletion of 12/15LOX differentially modulated the miRNA levels, downregulating miR-23a-3p (~20 fold; p < 0.05) and upregulating miR-125a-5p (~160 fold; p < 0.05) in AHF which promoted polarization of the macrophages towards reparative phenotype. Furthermore, 12/15LOX deletion markedly attenuated renal inflammation with reduced levels of NGAL and KIM-1 and apoptotic markers in the kidney during CHF. Conclusion: In risk-free mice during physiological cardiac repair, absence of 12/15LOX promoted reparative macrophages with marked activation of EP4 signaling thereby improving post-MI survival and limiting renal inflammation in acute and advanced HF. The future studies are warranted to advance the role of EETs in macrophage receptor biology.


Assuntos
Insuficiência Cardíaca/metabolismo , Lipoxigenase/deficiência , Receptores de Prostaglandina E Subtipo EP4/metabolismo , Animais , Apoptose/fisiologia , Araquidonato 12-Lipoxigenase/metabolismo , Araquidonato 15-Lipoxigenase/metabolismo , Biomarcadores/metabolismo , Linhagem Celular Tumoral , Doença Crônica , Regulação para Baixo/fisiologia , Coração/fisiologia , Ventrículos do Coração/metabolismo , Humanos , Inflamação/metabolismo , Mediadores da Inflamação/metabolismo , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/metabolismo , Infarto do Miocárdio/metabolismo , Neutrófilos/metabolismo , Regulação para Cima/fisiologia , Remodelação Ventricular/fisiologia
15.
Can J Vet Res ; 85(1): 68-71, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33390656

RESUMO

In many human cancers, the expression of the prostaglandin receptor EP4 (EP4R) is associated with the development of malignancy and a poor prognosis. The expression of EP4R has not yet been evaluated in canine tumors. The objective of this study was to characterize the messenger RNA (mRNA) expression of EP4R in canine osteosarcoma (OSA). Gene expression of EP4R was evaluated using RNA in-situ hybridization (RNAscope). In all canine OSA samples evaluated, strong universal positive expression of EP4R was identified. Gene expression was significantly higher in OSA tissue samples than in normal nasal turbinate bone, possibly implicating EP4R in the pathogenesis of canine OSA.


Assuntos
Neoplasias Ósseas/veterinária , Doenças do Cão/metabolismo , Osteossarcoma/veterinária , Receptores de Prostaglandina E Subtipo EP4/metabolismo , Animais , Neoplasias Ósseas/genética , Neoplasias Ósseas/metabolismo , Doenças do Cão/genética , Cães , Regulação Neoplásica da Expressão Gênica , Osteossarcoma/genética , Osteossarcoma/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Prostaglandina E Subtipo EP4/genética
16.
Brain Res ; 1750: 147153, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33049240

RESUMO

Prostaglandin E2 (PGE2) is a lipid mediator which plays a role in the generation of inflammatory and neuropathic pain. In the peripheral nervous system, PGE2 sensitizes nociceptive afferent neurons through E-prostanoid (EP) receptors. In the central nervous system, PGE2 modulates pain sensitivity and contributes to the development of neuropathic pain. However, the distribution of PGE2 and EP receptors in the spinal cord remains unclear. In the present study, we examined the expression of PGE2 synthases (microsomal PGE synthase [mPGES]-1, mPGES-2, and cytosolic PGE synthase [cPGES]) and EP receptors (EP1-4) in a rat model of neuropathic pain. We identified that mPGES-1 mRNA was upregulated in spinal endothelial cells after nerve injury and exhibited co-localization with cyclooxygenase-2 (COX-2). We detected that mPGES-2 mRNA and cPGES mRNA were expressed in spinal neurons and noted that their expression level was not affected by nerve injury. With respect to EP receptors, EP2 mRNA and EP4 mRNA were expressed in spinal neurons in the dorsal horn. EP3 mRNA was expressed in motor neurons, whereas EP1 mRNA was not detected in the spinal cord. Intrathecal injection of tumor necrosis factor alpha (TNFα) upregulated mPGES-1 mRNA in blood vessels in the spinal cord. Intrathecal injection of a TNFα-neutralizing antibody partially inhibited the upregulation of mPGES-1 mRNA after nerve injury. These results indicate that PGE2 is synthesized by COX-2/mPGES-1 in spinal endothelial cells after nerve injury. These results suggest that in neuropathic pain condition, endothelial cell-derived PGE2 may act on EP2 and EP4 receptors on spinal neurons and modulate pain sensitivity.


Assuntos
Neuralgia/fisiopatologia , Prostaglandina-E Sintases/metabolismo , Receptores de Prostaglandina E/metabolismo , Animais , Sistema Nervoso Central/metabolismo , Ciclo-Oxigenase 2/metabolismo , Modelos Animais de Doenças , Células Endoteliais/metabolismo , Expressão Gênica/genética , Oxirredutases Intramoleculares/metabolismo , Masculino , Limiar da Dor/efeitos dos fármacos , Prostaglandina-E Sintases/fisiologia , Ratos , Ratos Sprague-Dawley , Receptores de Prostaglandina E/fisiologia , Receptores de Prostaglandina E Subtipo EP4/metabolismo , Medula Espinal/fisiologia
17.
Biochem Pharmacol ; 183: 114352, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33278351

RESUMO

Treatment of patients with relapsed or refractory chronic lymphocytic leukemia (CLL) has significantly improved more recently with the approval of several new agents, including ibrutinib, idelalisib, and venetoclax. Despite the outstanding efficacies observed with these agents, these treatments are sometimes discontinued due to toxicity, unresponsiveness, transformation of the disease and/or resistance. Constitutive NF-κB activation that protects CLL cells from apoptotic stimuli represents one of molecular mechanisms that underlie the emergence of drug resistance. As prostaglandin E (EP)4 receptor agonists have been shown to successfully inhibit the NF-κB pathway in B-cell lymphoma cells, we investigated the potential of the highly specific EP4 receptor agonist L-902688 for the potential treatment of patients with CLL. We show here that low micromolar concentrations of L-902688 can indeed induce selective cytotoxicity towards several B-cell malignancies, including CLL. Moreover, L-902688-mediated activation of the EP4 receptor in patient derived CLL cells resulted in inhibition of the NF-κB pathway, cell proliferation, and induction of apoptosis. Most importantly, we show for the first time that in combination with ibrutinib, idelalisib, or venetoclax, L-902688 induces synergistic cytotoxic activity against patient derived CLL cells. To conclude, the modulation of NF-κB activity by EP4 receptor agonists represents an innovative approach to improve the treatment of patients with CLL. In particular, EP4 receptor agonists appear to represent promising adjuncts to the already existing therapies for patients with CLL due to these promising synergistic activities.


Assuntos
Adenina/análogos & derivados , Compostos Bicíclicos Heterocíclicos com Pontes/administração & dosagem , Leucemia Linfocítica Crônica de Células B , Piperidinas/administração & dosagem , Purinas/administração & dosagem , Pirrolidinonas/administração & dosagem , Quinazolinonas/administração & dosagem , Receptores de Prostaglandina E Subtipo EP4/agonistas , Sulfonamidas/administração & dosagem , Tetrazóis/administração & dosagem , Adenina/administração & dosagem , Adulto , Antineoplásicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Humanos , Células Jurkat , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Leucemia Linfocítica Crônica de Células B/metabolismo , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Receptores de Prostaglandina E Subtipo EP4/metabolismo , Células U937
18.
J Cell Physiol ; 236(6): 4764-4777, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33275302

RESUMO

Primary cilia have been found to function as mechanosensors in low-magnitude high-frequency vibration (LMHFV)-induced osteogenesis. The PGE2 also regulates bone homeostasis and mechanical osteogenesis through its receptor EP4 signaling, but its involvement in LMHFV-induced or in primary cilia-induced osteogenesis has not been investigated. We hypothesized that LMHFV stimulates osteoblast (OB) differentiation by activating the COX2-PGE2-EP pathway in a manner dependent on primary cilia and that primary cilia are also affected by the PGE2 pathway. In this study, through western blot analysis, RNA interference, enzyme-linked immunosorbent assay, real-time quantitative polymerase chain reaction, and cytochemical staining, we observed that COX2, mPGES-1, and PGE2 levels were markedly elevated in cells treated with LMHFV and were greatly decreased in LMHFV-treated cells following IFT88 silencing. EP4 expression was significantly increased in OBs following LMHFV treatment, but IFT88 silencing significantly blocked this increase. EP4 localized to the bases of primary cilia. LMHFV reduced the length and abundance of primary cilia, but the cells could self-repair their primary cilia after mechanical damage. EP4 antagonism significantly blocked the LMHFV-induced increase in IFT88 expression and blocked the recovery of primary cilia length and the proportion of cells with primary cilia. In addition, COX2 or EP4 antagonism disrupted LMHFV-induced osteogenesis. These results demonstrate the integration of and crosstalk between primary cilia and the COX2-PGE2-EP4 signaling pathway under mechanical stimulation.


Assuntos
Diferenciação Celular , Cílios/enzimologia , Ciclo-Oxigenase 2/metabolismo , Dinoprostona/metabolismo , Mecanotransdução Celular , Osteoblastos/enzimologia , Osteogênese , Receptores de Prostaglandina E Subtipo EP4/metabolismo , Células 3T3 , Animais , Diferenciação Celular/efeitos dos fármacos , Cílios/efeitos dos fármacos , Ciclo-Oxigenase 2/genética , Inibidores de Ciclo-Oxigenase 2/farmacologia , Camundongos , Osteoblastos/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Estimulação Física , Antagonistas de Prostaglandina/farmacologia , Prostaglandina-E Sintases/genética , Prostaglandina-E Sintases/metabolismo , Receptores de Prostaglandina E Subtipo EP4/antagonistas & inibidores , Receptores de Prostaglandina E Subtipo EP4/genética , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo , Vibração
19.
Structure ; 29(3): 252-260.e6, 2021 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-33264604

RESUMO

Prostaglandin E receptor EP4, a class A G protein-coupled receptor (GPCR), is a common drug target in various disorders, such as acute decompensated heart failure and ulcerative colitis. Here, we report the cryoelectron microscopy (cryo-EM) structure of the EP4-heterotrimeric G protein (Gs) complex with the endogenous ligand at a global resolution of 3.3 Å. In this structure, compared with that in the inactive EP4 structure, the sixth transmembrane domain is shifted outward on the intracellular side, although the shift is smaller than that in other class A GPCRs bound to Gs. Instead, the C-terminal helix of Gs is inserted toward TM2 of EP4, and the conserved C-terminal hook structure formsthe extended state. These structural features are formed by the conserved residues in prostanoid receptors (Phe542.39 and Trp3277.51). These findings may be important for the thorough understanding of the G protein-binding mechanism of EP4 and other prostanoid receptors.


Assuntos
Proteínas de Ligação ao GTP/química , Receptores de Prostaglandina E Subtipo EP4/química , Animais , Sítios de Ligação , Microscopia Crioeletrônica , Proteínas de Ligação ao GTP/metabolismo , Células HEK293 , Humanos , Simulação de Acoplamento Molecular , Ligação Proteica , Conformação Proteica em alfa-Hélice , Receptores de Prostaglandina E Subtipo EP4/metabolismo , Células Sf9 , Spodoptera
20.
J Pharmacol Exp Ther ; 376(2): 161-180, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33158942

RESUMO

There is a clear, unmet clinical need to identify new drugs to treat individuals with asthma, chronic obstructive pulmonary disease (COPD), and idiopathic pulmonary fibrosis (IPF) in whom current medications are either inactive or suboptimal. In preclinical models, EP4-receptor agonists display efficacy, but their mechanism of action is unclear. In this study, using human bronchial epithelial cells as a therapeutically relevant drug target, we hypothesized that changes in gene expression may play an important role. Several prostanoid receptor mRNAs were detected in BEAS-2B cells, human primary bronchial epithelial cells (HBECs) grown in submersion culture and HBECs grown at an air-liquid interface with PTGER4 predominating. By using the activation of a cAMP response element reporter in BEAS-2B cells as a surrogate of gene expression, Schild analysis determined that PTGER4 mRNAs encoded functional EP4-receptors. Moreover, inhibitors of phosphodiesterase 4 (roflumilast N-oxide [RNO]) and cAMP-dependent protein kinase augmented and attenuated, respectively, reporter activation induced by 2-[3-[(1R,2S,3R)-3-hydroxy-2-[(E,3S)-3-hydroxy-5-[2-(methoxymethyl)phenyl]pent-1-enyl]-5-oxo-cyclopentyl]sulphanylpropylsulphanyl] acetic acid (ONO-AE1-329), a selective EP4-receptor agonist. ONO-AE1-329 also enhanced dexamethasone-induced activation of a glucocorticoid response element reporter in BEAS-2B cells, which was similarly potentiated by RNO. In each airway epithelial cell variant, numerous genes that may impart therapeutic benefit in asthma, COPD, and/or IPF were differentially expressed by ONO-AE1-329, and those changes were often augmented by RNO and/or dexamethasone. We submit that an EP4-receptor agonist, either alone or as a combination therapy, may be beneficial in individuals with chronic lung diseases in whom current treatment options are inadequate. SIGNIFICANCE STATEMENT: Using human bronchial epithelial cells as a therapeutically relevant drug target, we report that EP4-receptor activation promoted gene expression changes that could provide therapeutic benefit in individuals with asthma, COPD, and IPF in whom current treatment options are ineffective or suboptimal.


Assuntos
Brônquios/citologia , Células Epiteliais/metabolismo , Receptores de Prostaglandina E Subtipo EP4/metabolismo , Aminopiridinas/farmacologia , Anti-Inflamatórios/farmacologia , Benzamidas/farmacologia , Linhagem Celular , AMP Cíclico/metabolismo , Ciclopropanos/farmacologia , Dexametasona/farmacologia , Células Epiteliais/efeitos dos fármacos , Humanos , Éteres Metílicos/farmacologia , Inibidores da Fosfodiesterase 4/farmacologia , Receptores de Prostaglandina E Subtipo EP4/agonistas , Elementos de Resposta , Transcriptoma
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...