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1.
Yakugaku Zasshi ; 139(11): 1403-1415, 2019.
Artigo em Japonês | MEDLINE | ID: mdl-31685737

RESUMO

For my Ph.D. research topic, I isolated endogenous morphine-like analgesic dipeptide, kyotorphin, which mediates Met-enkephalin release, and discovered kyotorphin synthetase, a putative receptor and antagonist. Furthermore, I succeeded in purifying µ-opioid receptor and functional reconstitution with purified G proteins. After receiving my full professor position at Nagasaki University in 1996, I worked on two topics of research, molecular mechanisms of chronic pain through lysophosphatidic acid (LPA) and identification and characterization of neuroprotective protein, prothymosin α. In a series of studies, we have shown that LPA signaling defines the molecular mechanisms of neuropathic pain and fibromyalgia in terms of development and maintenance. Above all, the discovery of feed-forward system in LPA production and pain memory may contribute to better understanding of chronic pain and future analgesic drug discovery. Regarding prothymosin α, we first discovered it as neuronal necrosis-inhibitory molecule through two independent mechanisms, such as toll-like receptor and F0/F1 ATPase, both which protect neurons through indirect mechanisms. Prothymosin α is released by non-classical and non-vesicular mechanisms on various stresses, such as ischemia, starvation, and heat-shock. Thus it may be called a new type of neuroprotective damage-associated molecular patterns (DAMPs)/Alarmins. Heterozygotic mice showed a defect in memory-learning and neurogenesis as well as anxiogenic behaviors. Small peptide, P6Q derived from prothymosin α retains neuroprotective actions, which include blockade of cerebral hemorrhage caused by late treatment with tissue plasminogen activator in the stroke model in mice.


Assuntos
Dor Crônica/etiologia , Dor Crônica/genética , Fármacos Neuroprotetores , Precursores de Proteínas , Receptores de Ácidos Lisofosfatídicos/fisiologia , Transdução de Sinais/fisiologia , Timosina/análogos & derivados , Animais , Endorfinas , Humanos , Camundongos , Precursores de Proteínas/metabolismo , ATPases Translocadoras de Prótons , Receptores de Ácidos Lisofosfatídicos/metabolismo , Receptores Opioides , Acidente Vascular Cerebral , Timosina/metabolismo , Receptores Toll-Like
2.
Life Sci ; 220: 194-200, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30584899

RESUMO

Lysophosphatidic acid (LPA) is the simplest phospholipid found in nature. LPA is mainly biosynthesized in tissues and cells by autotoxin and PA-PLA1α/PA-PLA1ß and is degraded by lipid phosphate phosphatases (LPPs). It is an important component of biofilm, an extracellular signal transmitter and intracellular second messenger. After targeting to endothelial differentiation gene (Edg) family LPA receptors (LPA1, LPA2, LPA3) and non-Edg family LPA receptors (LPA4, LPA5, LPA6), LPA mediates physiological and pathological processes such as embryonic development, angiogenesis, tumor progression, fibrogenesis, wound healing, ischemia/reperfusion injury, and inflammatory reactions. These processes are induced through signaling pathways including mitogen-activated protein kinase (MAPK), phosphatidylinositol-3-kinase (PI3K)/Akt, protein kinase C (PKC)-GSK3ß-ß-catenin, Rho, Stat, and hypoxia-inducible factor 1-alpha (HIF-1α). LPA is involved in multiple physiological and pathological processes in the skin. It not only regulates skin function but also plays an important role in hair follicle development, skin wound healing, pruritus, skin tumors, and scleroderma. Pharmacological inhibition of LPA synthesis or antagonization of LPA receptors is a new strategy for the treatment of various skin disorders. This review focuses on the current understanding of the pathophysiologic role of LPA in the skin.


Assuntos
Lisofosfolipídeos/metabolismo , Lisofosfolipídeos/fisiologia , Pele/metabolismo , Animais , Folículo Piloso/fisiologia , Humanos , Lisofosfolipídeos/farmacologia , Receptores de Ácidos Lisofosfatídicos/metabolismo , Receptores de Ácidos Lisofosfatídicos/fisiologia , Transdução de Sinais/efeitos dos fármacos , Pele/patologia , Cicatrização/fisiologia
3.
J Pharmacol Sci ; 136(2): 93-96, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29409686

RESUMO

Lysophosphatidic acid (LPA) and LPA1 receptor signaling play a crucial role in the initiation of peripheral nerve injury-induced neuropathic pain through the alternation of pain-related genes/proteins expression and demyelination. However, LPA and its signaling in the brain are still poorly understood. In the present study, we revealed that the LPA5 receptor expression in corpus callosum elevated after the initiation of demyelination, and the hyperalgesia through Aδ-fibers following cuprizone-induced demyelination was mediated by LPA5 signaling. These data suggest that LPA5 signaling may play a key role in the mechanisms underlying neuropathic pain following demyelination in the brain.


Assuntos
Cuprizona/efeitos adversos , Modelos Animais de Doenças , Esclerose Múltipla/etiologia , Esclerose Múltipla/genética , Neuralgia/etiologia , Neuralgia/genética , Receptores de Ácidos Lisofosfatídicos/fisiologia , Transdução de Sinais/fisiologia , Animais , Corpo Caloso/metabolismo , Feminino , Expressão Gênica , Lisofosfolipídeos/fisiologia , Masculino , Camundongos Endogâmicos , Esclerose Múltipla/metabolismo , Receptores de Ácidos Lisofosfatídicos/genética , Receptores de Ácidos Lisofosfatídicos/metabolismo
4.
Am J Pathol ; 188(2): 353-366, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29128569

RESUMO

Intestinal epithelial cells form a barrier that is critical in protecting the host from the hostile luminal environment. Previously, we showed that lysophosphatidic acid (LPA) receptor 1 regulates proliferation of intestinal epithelial cells, such that the absence of LPA1 mitigates the epithelial wound healing process. This study provides evidence that LPA1 is important for the maintenance of epithelial barrier integrity. The epithelial permeability, determined by fluorescently labeled dextran flux and transepithelial resistance, is increased in the intestine of mice with global deletion of Lpar1, Lpar1-/- (Lpa1-/-). Serum liposaccharide level and bacteria loads in the intestinal mucosa and peripheral organs were elevated in Lpa1-/- mice. Decreased claudin-4, caudin-7, and E-cadherin expression in Lpa1-/- mice further suggested defective apical junction integrity in these mice. Regulation of LPA1 expression in Caco-2 cells modulated epithelial permeability and the expression levels of junctional proteins. The increased epithelial permeability in Lpa1-/- mice correlated with increased susceptibility to an experimental model of colitis. This resulted in more severe inflammation and increased mortality compared with control mice. Treatment of Caco-2 cells with tumor necrosis factor-α and interferon-γ significantly increased paracellular permeability, which was blocked by cotreatment with LPA, but not LPA1 knockdown cells. Similarly, orally given LPA blocked tumor necrosis factor-mediated intestinal barrier defect in mice. LPA1 plays a significant role in maintenance of epithelial barrier in the intestine via regulation of apical junction integrity.


Assuntos
Colite/fisiopatologia , Mucosa Intestinal/metabolismo , Receptores de Ácidos Lisofosfatídicos/fisiologia , Animais , Carga Bacteriana , Células CACO-2 , Colite/genética , Colite/microbiologia , Suscetibilidade a Doenças , Deleção de Genes , Regulação da Expressão Gênica , Humanos , Absorção Intestinal/fisiologia , Mucosa Intestinal/microbiologia , Masculino , Camundongos Knockout , Permeabilidade , Receptores de Ácidos Lisofosfatídicos/deficiência , Receptores de Ácidos Lisofosfatídicos/genética
5.
J Neurochem ; 143(2): 183-197, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28815598

RESUMO

Both lysophosphatidic acid (LPA) and antidepressants have been shown to affect neuronal survival and differentiation, but whether LPA signalling participates in the action of antidepressants is still unknown. In this study, we examined the role of LPA receptors in the regulation of extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) activity and neuronal survival by the tetracyclic antidepressants, mianserin and mirtazapine in hippocampal neurons. In HT22 immortalized hippocampal cells, antidepressants and LPA induced a time- and concentration-dependent stimulation of ERK1/2 phosphorylation. This response was inhibited by either LPA1 and LPA1/3 selective antagonists or siRNA-induced LPA1 down-regulation, and enhanced by LPA1 over-expression. Conversely, the selective LPA2 antagonist H2L5186303 had no effect. Antidepressants induced cyclic AMP response element binding protein phosphorylation and this response was prevented by LPA1 blockade. ERK1/2 stimulation involved pertussis toxin-sensitive G proteins, Src tyrosine kinases and fibroblast growth factor receptor (FGF-R) activity. Tyrosine phosphorylation of FGF-R was enhanced by antidepressants through LPA1 . Serum withdrawal induced apoptotic death, as indicated by increased annexin V staining, caspase activation and cleavage of poly-ADP-ribose polymerase. Antidepressants inhibited the apoptotic cascade and this protective effect was curtailed by blockade of either LPA1 , ERK1/2 or FGF-R activity. Moreover, in primary mouse hippocampal neurons, mianserin acting through LPA1 increased phospho-ERK1/2 and protected from apoptosis induced by removal of growth supplement. These data indicate that in neurons endogenously expressed LPA1 receptors mediate intracellular signalling and neuroprotection by tetracyclic antidepressants.


Assuntos
Antidepressivos de Segunda Geração/farmacologia , Antidepressivos Tricíclicos/farmacologia , Hipocampo/fisiologia , Neurônios/fisiologia , Neuroproteção/fisiologia , Receptores de Ácidos Lisofosfatídicos/fisiologia , Animais , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Células Cultivadas , Relação Dose-Resposta a Droga , Feminino , Hipocampo/efeitos dos fármacos , Humanos , Líquido Intracelular/efeitos dos fármacos , Líquido Intracelular/fisiologia , Masculino , Mianserina/farmacologia , Camundongos , Neurônios/efeitos dos fármacos , Neuroproteção/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia
6.
J Am Soc Nephrol ; 28(11): 3300-3311, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28739650

RESUMO

Lysophosphatidic acid (LPA) functions through activation of LPA receptors (LPARs). LPA-LPAR signaling has been implicated in development of fibrosis. However, the role of LPA-LPAR signaling in development of diabetic nephropathy (DN) has not been studied. We examined whether BMS002, a novel dual LPAR1 and LPAR3 antagonist, affects development of DN in endothelial nitric oxide synthase-knockout db/db mice. Treatment of these mice with BMS002 from 8 to 20 weeks of age led to a significant reduction in albuminuria, similar to that observed with renin-angiotensin system inhibition (losartan plus enalapril). LPAR inhibition also prevented the decline in GFR observed in vehicle-treated mice, such that GFR at week 20 differed significantly between vehicle and LPAR inhibitor groups (P<0.05). LPAR inhibition also reduced histologic glomerular injury; decreased the expression of profibrotic and fibrotic components, including fibronectin, α-smooth muscle actin, connective tissue growth factor, collagen I, and TGF-ß; and reduced renal macrophage infiltration and oxidative stress. Notably, LPAR inhibition slowed podocyte loss (podocytes per glomerulus ±SEM at 8 weeks: 667±40, n=4; at 20 weeks: 364±18 with vehicle, n=7, and 536±12 with LPAR inhibition, n=7; P<0.001 versus vehicle). Finally, LPAR inhibition minimized the production of 4-hydroxynonenal (4-HNE), a marker of oxidative stress, in podocytes and increased the phosphorylation of AKT2, an indicator of AKT2 activity, in kidneys. Thus, the LPAR antagonist BMS002 protects against GFR decline and attenuates development of DN through multiple mechanisms. LPAR antagonism might provide complementary beneficial effects to renin-angiotensin system inhibition to slow progression of DN.


Assuntos
Nefropatias Diabéticas/prevenção & controle , Receptores de Ácidos Lisofosfatídicos/antagonistas & inibidores , Animais , Diabetes Mellitus Tipo 2/complicações , Nefropatias Diabéticas/etiologia , Modelos Animais de Doenças , Camundongos , Receptores de Ácidos Lisofosfatídicos/fisiologia
7.
Biochem Biophys Res Commun ; 487(1): 103-108, 2017 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-28392399

RESUMO

Human lysophosphatidic acid receptor 2 (LPA2), a member of the G-protein coupled receptor family, mediates lysophosphatidic acid (LPA)-dependent signaling by recruiting various G proteins. Particularly, it is directly implicated in the progression of colorectal and ovarian cancer through G protein signaling cascades. To investigate the biochemical binding properties of LPA2 against various alpha subunits of G protein (Gα), a functional recombinant LPA2 was overexpressed in E. coli membrane with a P9∗ expression system, and the purified protein was stabilized with an amphipathic polymer that had been synthesized by coupling octylamine, glucosamine, and diethyl aminoproylamine at the carboxylic groups of poly-γ-glutamic acid. The purified LPA2 stabilized with the amphipathic polymer showed selective binding activity to the various Gα proteins as well as agonist-dependent dissociation from Gαi3. Understanding the binding properties of LPA2 against various Gα proteins advances the understanding of downstream signaling cascades of LPA2. The functional LPA2 prepared using a P9∗ expression system and an amphipathic polymer could also facilitate the development of LPA2-targeting drugs.


Assuntos
Escherichia coli/metabolismo , Subunidades alfa de Proteínas de Ligação ao GTP/química , Vírus da Anemia Infecciosa Equina/genética , Receptores de Ácidos Lisofosfatídicos/química , Receptores de Ácidos Lisofosfatídicos/fisiologia , Sítios de Ligação , Clonagem Molecular/métodos , Escherichia coli/genética , Humanos , Ligação Proteica
8.
J Physiol ; 595(8): 2681-2698, 2017 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-28176353

RESUMO

KEY POINTS: Lysophosphatidic acid (LPA) is an itch mediator, but not a pain mediator by a cheek injection model. Dorsal root ganglion neurons directly respond to LPA depending on transient receptor potential ankyrin 1 (TRPA1) and vanilloid 1 (TRPV1). LPA-induced itch-related behaviours are decreased in TRPA1-knockout (KO), TRPV1KO or TRPA1TRPV1 double KO mice. TRPA1 and TRPV1 channels are activated by intracellular LPA, but not by extracellular LPA following LPA5 receptor activation with an activity of Ca2+ -independent phospholipase A2 and phospholipase D. Intracellular LPA interaction sites of TRPA1 are KK672-673 and KR977-978 (K: lysine, R: arginine). ABSTRACT: Intractable and continuous itch sensations often accompany diseases such as atopic dermatitis, neurogenic lesions, uremia and cholestasis. Lysophosphatidic acid (LPA) is an itch mediator found in cholestatic itch patients and it induces acute itch and pain in experimental rodent models. However, the molecular mechanism by which LPA activates peripheral sensory neurons remains unknown. In this study, we used a cheek injection method in mice to reveal that LPA induced itch-related behaviours but not pain-related behaviours. The LPA-induced itch behaviour and cellular effects were dependent on transient receptor potential ankyrin 1 (TRPA1) and vanilloid 1 (TRPV1), which are important for itch signal transduction. We also found that, among the six LPA receptors, the LPA5 receptor had the greatest involvement in itching. Furthermore, we demonstrated that phospholipase D (PLD) plays a critical role downstream of LPA5 and that LPA directly and intracellularly activates TRPA1 and TRPV1. These results suggest a unique mechanism by which cytoplasmic LPA produced de novo could activate TRPA1 and TRPV1. We conclude that LPA-induced itch is mediated by LPA5 , PLD, TRPA1 and TRPV1 signalling, and thus targeting TRPA1, TRPV1 or PLD could be effective for cholestatic itch interventions.


Assuntos
Lisofosfolipídeos/toxicidade , Fosfolipase D/fisiologia , Prurido/metabolismo , Receptores de Ácidos Lisofosfatídicos/fisiologia , Canais de Cátion TRPV/fisiologia , Canais de Receptores Transientes de Potencial/fisiologia , Animais , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Prurido/induzido quimicamente , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Canal de Cátion TRPA1
9.
J Hepatol ; 66(5): 919-929, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28126468

RESUMO

BACKGROUND & AIMS: Chronic hepatitis C is a global health problem with an estimated 170 million hepatitis C virus (HCV) infected individuals at risk of progressive liver disease and hepatocellular carcinoma (HCC). Autotaxin (ATX, gene name: ENPP2) is a phospholipase with diverse roles in the physiological and pathological processes including inflammation and oncogenesis. Clinical studies have reported increased ATX expression in chronic hepatitis C, however, the pathways regulating ATX and its role in the viral life cycle are not well understood. METHODS: In vitro hepatocyte and ex vivo liver culture systems along with chimeric humanized liver mice and HCC tissue enabled us to assess the interplay between ATX and the HCV life cycle. RESULTS: HCV infection increased hepatocellular ATX RNA and protein expression. HCV infection stabilizes hypoxia inducible factors (HIFs) and we investigated a role for these transcription factors to regulate ATX. In vitro studies show that low oxygen increases hepatocellular ATX expression and transcriptome analysis showed a positive correlation between ATX mRNA levels and hypoxia gene score in HCC tumour tissue associated with HCV and other aetiologies. Importantly, inhibiting ATX-lysophosphatidic acid (LPA) signalling reduced HCV replication, demonstrating a positive role for this phospholipase in the viral life cycle. LPA activates phosphoinositide-3-kinase that stabilizes HIF-1α and inhibiting the HIF signalling pathway abrogates the pro-viral activity of LPA. CONCLUSIONS: Our data support a model where HCV infection increases ATX expression which supports viral replication and HCC progression. LAY SUMMARY: Chronic hepatitis C is a global health problem with infected individuals at risk of developing liver disease that can progress to hepatocellular carcinoma. Autotaxin generates the biologically active lipid lysophosphatidic acid that has been reported to play a tumorigenic role in a wide number of cancers. In this study we show that hepatitis C virus infection increases autotaxin expression via hypoxia inducible transcription factor and provides an environment in the liver that promotes fibrosis and liver injury. Importantly, we show a new role for lysophosphatidic acid in positively regulating hepatitis C virus replication.


Assuntos
Hepacivirus/fisiologia , Diester Fosfórico Hidrolases/fisiologia , Receptores de Ácidos Lisofosfatídicos/fisiologia , Replicação Viral , Animais , Linhagem Celular , Hepatite C Crônica/complicações , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/fisiologia , Neoplasias Hepáticas/etiologia , Camundongos , Diester Fosfórico Hidrolases/genética , Regiões Promotoras Genéticas , RNA Mensageiro/análise , Transdução de Sinais
10.
Mediators Inflamm ; 2017: 9173090, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29430083

RESUMO

Lysophosphatidic acid (LPA) is a ubiquitous lysophospholipid and one of the main membrane-derived lipid signaling molecules. LPA acts as an autocrine/paracrine messenger through at least six G protein-coupled receptors (GPCRs), known as LPA1-6, to induce various cellular processes including wound healing, differentiation, proliferation, migration, and survival. LPA receptors and autotaxin (ATX), a secreted phosphodiesterase that produces this phospholipid, are overexpressed in many cancers and impact several features of the disease, including cancer-related inflammation, development, and progression. Many ongoing studies aim to understand ATX-LPA axis signaling in cancer and its potential as a therapeutic target. In this review, we discuss the evidence linking LPA signaling to cancer-related inflammation and its impact on cancer progression.


Assuntos
Inflamação/etiologia , Lisofosfolipídeos/fisiologia , Neoplasias/etiologia , Diester Fosfórico Hidrolases/fisiologia , Humanos , Lisofosfolipídeos/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Receptores de Ácidos Lisofosfatídicos/fisiologia , Transdução de Sinais/fisiologia
11.
J Pharmacol Sci ; 132(2): 162-165, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27681370

RESUMO

Lysophosphatidic acid (LPA) initiates demyelination following peripheral nerve injury, which causes neuropathic pain. Our previous in vivo and ex vivo studies using mice have demonstrated that LPA-induced demyelination of spinal dorsal roots is attributed by the LPA1-type receptor-mediated down-regulation of myelin-related molecules, such as MBP and MPZ. In this study using S16 mature-type Schwann cells, we found that LPA-induced down-regulation of myelin-related genes is attributed by the activation of LPA1 receptor, Rho kinase, and p300, leading to an acetylation of NFκB, which down-regulates the transcription of Sox10, MBP and MPZ genes.


Assuntos
Inativação Gênica/fisiologia , Bainha de Mielina/metabolismo , NF-kappa B/metabolismo , Receptores de Ácidos Lisofosfatídicos/fisiologia , Células de Schwann/metabolismo , Quinases Associadas a rho/fisiologia , Acetilação , Animais , Linhagem Celular , Camundongos , Bainha de Mielina/genética
12.
Biol Reprod ; 94(5): 104, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27030044

RESUMO

Lysophosphatidic acid (LPA) is a phospholipid with a variety of fatty acyl groups that mediates diverse biological effects on various types of cells through specific G protein-coupled receptors. LPA appears to play a significant role in many reproductive processes, including luteolysis, implantation, and placentation. Our previous study in pigs demonstrated that LPA and the LPA receptor system are present at the maternal-conceptus interface and that LPA increases uterine endometrial expression of prostaglandin-endoperoxide synthase 2 (PTGS2) through LPA receptor 3 (LPAR3). However, the role of LPA in conceptuses during early pregnancy has not been determined. Therefore, this study examined the effects of LPA in cell proliferation, migration, and activation of the intracellular signaling pathway in porcine conceptuses by using an established porcine trophectoderm (pTr) cell line isolated from Day 12 conceptuses. All examined LPA species with various fatty acid lengths increased proliferation and migration of pTr cells as the dosage increased. Immunoblot analyses found that LPA activated intracellular signaling molecules, extracellular signal-regulated kinase 1/2 (ERK1/2), ribosomal protein S6 kinase 90 kDa (P90RSK), ribosomal protein S6 (RPS6), and P38 in pTr cells. Furthermore, LPA increased expression of PTGS2 and urokinase-type plasminogen activator (PLAU), and the LPA-induced increases in PTGS2 and PLAU expression were inhibited by LPAR3 siRNA. Collectively, these results showed that LPA promotes proliferation, migration, and differentiation of pTr cells by activating the ERK1/2-P90RSK-RPS6 and P38 pathways, indicating that the LPA-LPAR3 system may be involved in the development of trophoblast during early pregnancy in pigs.


Assuntos
Implantação do Embrião , Desenvolvimento Embrionário , Lisofosfolipídeos/metabolismo , Receptores de Ácidos Lisofosfatídicos/fisiologia , Suínos/embriologia , Animais , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Ectoderma/efeitos dos fármacos , Ectoderma/metabolismo , Implantação do Embrião/genética , Desenvolvimento Embrionário/genética , Feminino , Lisofosfolipídeos/farmacologia , Gravidez , Receptores de Ácidos Lisofosfatídicos/genética , Transdução de Sinais/genética , Trofoblastos/efeitos dos fármacos , Trofoblastos/metabolismo
13.
Neuropharmacology ; 103: 92-103, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26700247

RESUMO

BACKGROUND: Lysophosphatidic acid species (LPA) are lipid bioactive signaling molecules that have been recently implicated in the modulation of emotional and motivational behaviors. The present study investigates the consequences of either genetic deletion or pharmacological blockade of lysophosphatidic acid receptor-1 (LPA1) in alcohol consumption. METHODS: The experiments were performed in alcohol-drinking animals by using LPA1-null mice and administering the LPA1 receptor antagonist Ki16425 in both mice and rats. RESULTS: In the two-bottle free choice paradigm, the LPA1-null mice preferred the alcohol more than their wild-type counterparts. Whereas the male LPA1-null mice displayed this higher preference at all doses tested, the female LPA1-null mice only consumed more alcohol at 6% concentration. The male LPA1-null mice were then further characterized, showing a notably increased ethanol drinking after a deprivation period and a reduced sleep time after acute ethanol administration. In addition, LPA1-null mice were more anxious than the wild-type mice in the elevated plus maze test. For the pharmacological experiments, the acute administration of the antagonist Ki16425 consistently increased ethanol consumption in both wild-type mice and rats; while it did not modulate alcohol drinking in the LPA1-null mice and lacked intrinsic rewarding properties and locomotor effects in a conditioned place preference paradigm. In addition, LPA1-null mice exhibited a marked reduction on the expression of glutamate-transmission-related genes in the prefrontal cortex similar to those described in alcohol-exposed rodents. CONCLUSIONS: Results suggest a relevant role for the LPA/LPA1 signaling system in alcoholism. In addition, the LPA1-null mice emerge as a new model for genetic vulnerability to excessive alcohol drinking. The pharmacological manipulation of LPA1 receptor arises as a new target for the study and treatment of alcoholism.


Assuntos
Consumo de Bebidas Alcoólicas/fisiopatologia , Receptores de Ácidos Lisofosfatídicos/fisiologia , Consumo de Bebidas Alcoólicas/genética , Animais , Ansiedade/genética , Ansiedade/fisiopatologia , Canabinoides/metabolismo , Etanol/administração & dosagem , Feminino , Ácido Glutâmico/metabolismo , Isoxazóis/administração & dosagem , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Córtex Pré-Frontal/metabolismo , Propionatos/administração & dosagem , Ratos , Ratos Wistar , Receptores de Ácidos Lisofosfatídicos/antagonistas & inibidores , Receptores de Ácidos Lisofosfatídicos/genética , Reflexo de Endireitamento/efeitos dos fármacos , Sono/efeitos dos fármacos
14.
Domest Anim Endocrinol ; 54: 15-29, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26379100

RESUMO

Assisted reproductive technologies, including in vitro embryo production (IVP), have been successfully used in animal reproduction to optimize breeding strategies for improved production and health in animal husbandry. Despite the progress in IVP techniques over the years, further improvements in in vitro embryo culture systems are required for the enhancement of oocyte and embryo developmental competence. One of the most important issues associated with IVP procedures is the optimization of the in vitro culture of oocytes and embryos. Studies in different species of animals and in humans have identified important roles for receptor-mediated lysophosphatidic acid (LPA) signaling in multiple aspects of human and animal reproductive tract function. The data on LPA signaling in the ovary and uterus suggest that LPA can directly contribute to embryo-maternal interactions via its influence on early embryo development beginning from the influence of the ovarian environment on the oocyte to the influence of the uterine environment on the preimplantation embryo. This review discusses the current status of LPA as a potential supplement in oocyte maturation, fertilization, and embryo culture media and current views on the potential involvement of the LPA signaling pathway in early embryo development.


Assuntos
Desenvolvimento Embrionário/efeitos dos fármacos , Lisofosfolipídeos/farmacologia , Animais , Apoptose , Blastocisto/fisiologia , Meios de Cultura , Células do Cúmulo/fisiologia , Técnicas de Cultura Embrionária , Feminino , Fertilização In Vitro/efeitos dos fármacos , Humanos , Técnicas de Maturação in Vitro de Oócitos , Lisofosfolipídeos/fisiologia , Meiose , Oócitos/fisiologia , Ovário/fisiologia , Receptores de Ácidos Lisofosfatídicos/fisiologia , Transdução de Sinais , Útero/fisiologia
15.
J Urol ; 194(1): 238-44, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25524242

RESUMO

PURPOSE: LPA is one of several physiologically active lipid mediators that promote cell proliferation and invasion, and are present in serum, ascites and urine. LPA receptor is a G-protein coupled receptor that is considered a potential therapeutic target for some malignant cancers. We evaluated the expression of LPA receptors in bladder cancer and the effect of LPA in bladder cancer invasion. MATERIALS AND METHODS: Using real-time polymerase chain reaction and immunohistochemical staining we determined LPA receptor expression in bladder cancer specimens from patients with bladder cancer, including 12 with Ta or T1 and 15 with T2-T4 disease. ROCK expression, myosin light chain phosphorylation and Matrigel™ invasion assays were done and morphological observations were made to assess LPA effects in T24 cells, which were derived from bladder cancer. RESULTS: Notably LPA1 mRNA expression was significantly higher in muscle invasive bladder cancer specimens than in nonmuscle invasive specimens. Strong LPA1 expression was evident on cell membranes in muscle invasive specimens. T24 cell invasion was increased by LPA treatment and invasiveness was decreased by LPA1 siRNA or LPA1 inhibitor. LPA treatment increased ROCK1 expression and myosin light chain phosphorylation, and induced morphological changes, including lamellipodia formation and cell rounding. CONCLUSIONS: Results indicate that LPA signaling via LPA1 activation promoted bladder cancer invasion. LPA1 might be useful to detect bladder cancer with highly invasive potential and become a new therapeutic target for invasive bladder cancer treatment.


Assuntos
Receptores de Ácidos Lisofosfatídicos/biossíntese , Receptores de Ácidos Lisofosfatídicos/fisiologia , Neoplasias da Bexiga Urinária/metabolismo , Neoplasias da Bexiga Urinária/patologia , Idoso , Feminino , Humanos , Masculino , Invasividade Neoplásica , Células Tumorais Cultivadas , Neoplasias da Bexiga Urinária/cirurgia
16.
Brain Struct Funct ; 220(6): 3701-20, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25226845

RESUMO

Lysophosphatidic acid (LPA) is an intercellular signaling lipid that regulates multiple cellular functions, acting through specific G-protein coupled receptors (LPA(1-6)). Our previous studies using viable Malaga variant maLPA1-null mice demonstrated the requirement of the LPA1 receptor for normal proliferation, differentiation, and survival of the neuronal precursors. In the cerebral cortex LPA1 is expressed extensively in differentiating oligodendrocytes, in parallel with myelination. Although exogenous LPA-induced effects have been investigated in myelinating cells, the in vivo contribution of LPA1 to normal myelination remains to be demonstrated. This study identified a relevant in vivo role for LPA1 as a regulator of cortical myelination. Immunochemical analysis in adult maLPA1-null mice demonstrated a reduction in the steady-state levels of the myelin proteins MBP, PLP/DM20, and CNPase in the cerebral cortex. The myelin defects were confirmed using magnetic resonance spectroscopy and electron microscopy. Stereological analysis limited the defects to adult differentiating oligodendrocytes, without variation in the NG2+ precursor cells. Finally, a possible mechanism involving oligodendrocyte survival was demonstrated by the impaired intracellular transport of the PLP/DM20 myelin protein which was accompanied by cellular loss, suggesting stress-induced apoptosis. These findings describe a previously uncharacterized in vivo functional role for LPA1 in the regulation of oligodendrocyte differentiation and myelination in the CNS, underlining the importance of the maLPA1-null mouse as a model for the study of demyelinating diseases.


Assuntos
Diferenciação Celular , Córtex Cerebral/fisiologia , Bainha de Mielina/fisiologia , Oligodendroglia/fisiologia , Receptores de Ácidos Lisofosfatídicos/fisiologia , Animais , Apoptose , Axônios/ultraestrutura , Córtex Cerebral/metabolismo , Córtex Cerebral/ultraestrutura , Espectroscopia de Ressonância Magnética , Masculino , Camundongos , Camundongos Knockout , Proteínas da Mielina/metabolismo , Bainha de Mielina/metabolismo , Bainha de Mielina/ultraestrutura , Transporte Proteico , Receptores de Ácidos Lisofosfatídicos/genética
17.
Exp Cell Res ; 333(2): 171-7, 2015 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-25499971

RESUMO

Lysophospholipids (LPs), including lysophosphatidic acid (LPA), sphingosine 1-phospate (S1P), lysophosphatidylinositol (LPI), and lysophosphatidylserine (LysoPS), are bioactive lipids that transduce signals through their specific cell-surface G protein-coupled receptors, LPA1-6, S1P1-5, LPI1, and LysoPS1-3, respectively. These LPs and their receptors have been implicated in both physiological and pathophysiological processes such as autoimmune diseases, neurodegenerative diseases, fibrosis, pain, cancer, inflammation, metabolic syndrome, bone formation, fertility, organismal development, and other effects on most organ systems. Advances in the LP receptor field have enabled the development of novel small molecules targeting LP receptors for several diseases. Most notably, fingolimod (FTY720, Gilenya, Novartis), an S1P receptor modulator, became the first FDA-approved medicine as an orally bioavailable drug for treating relapsing forms of multiple sclerosis. This success is currently being followed by multiple, mechanistically related compounds targeting S1P receptor subtypes, which are in various stages of clinical development. In addition, an LPA1 antagonist, BMS-986020 (Bristol-Myers Squibb), is in Phase 2 clinical development for treating idiopathic pulmonary fibrosis, as a distinct compound, SAR100842 (Sanofi) for the treatment of systemic sclerosis and related fibrotic diseases. This review summarizes the current state of drug discovery in the LP receptor field.


Assuntos
Receptores de Ácidos Lisofosfatídicos/antagonistas & inibidores , Receptores de Lisoesfingolipídeo/antagonistas & inibidores , Animais , Descoberta de Drogas , Humanos , Lisofosfolipídeos/fisiologia , Terapia de Alvo Molecular , Esclerose Múltipla/tratamento farmacológico , Receptores de Ácidos Lisofosfatídicos/fisiologia , Receptores de Lisoesfingolipídeo/fisiologia , Transdução de Sinais , Esfingosina/análogos & derivados , Esfingosina/fisiologia
18.
J Pathol ; 235(3): 456-65, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25294670

RESUMO

Undifferentiated nasopharyngeal carcinoma (NPC) is a highly metastatic disease that is consistently associated with Epstein-Barr virus (EBV) infection. In this study, we have investigated the contribution of lysophosphatidic acid (LPA) signalling to the pathogenesis of NPC. Here we demonstrate two distinct functional roles for LPA in NPC. First, we show that LPA enhances the migration of NPC cells and second, that it can inhibit the activity of EBV-specific cytotoxic T cells. Focusing on the first of these phenotypes, we show that one of the LPA receptors, LPA receptor 5 (LPAR5), is down-regulated in primary NPC tissues and that this down-regulation promotes the LPA-induced migration of NPC cell lines. Furthermore, we found that EBV infection or ectopic expression of the EBV-encoded LMP2A was sufficient to down-regulate LPAR5 in NPC cell lines. Our data point to a central role for EBV in mediating the oncogenic effects of LPA in NPC and identify LPA signalling as a potential therapeutic target in this disease.


Assuntos
Regulação para Baixo/fisiologia , Infecções por Vírus Epstein-Barr/fisiopatologia , Regulação Neoplásica da Expressão Gênica/fisiologia , Lisofosfolipídeos/fisiologia , Neoplasias Nasofaríngeas/fisiopatologia , Receptores de Ácidos Lisofosfatídicos/fisiologia , Transdução de Sinais/fisiologia , Adenocarcinoma/patologia , Adenocarcinoma/fisiopatologia , Carcinoma , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Herpesvirus Humano 4/fisiologia , Humanos , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/patologia , Diester Fosfórico Hidrolases/fisiologia , Receptores de Ácidos Lisofosfatídicos/genética , Linfócitos T Citotóxicos/patologia , Proteínas da Matriz Viral/fisiologia
19.
J Biol Chem ; 289(10): 6551-64, 2014 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-24429286

RESUMO

Lysophosphatidic acid (LPA) is a natural bioactive lipid that acts through six different G protein-coupled receptors (LPA1-6) with pleiotropic activities on multiple cell types. We have previously demonstrated that LPA is necessary for successful in vitro osteoclastogenesis of bone marrow cells. Bone cells controlling bone remodeling (i.e. osteoblasts, osteoclasts, and osteocytes) express LPA1, but delineating the role of this receptor in bone remodeling is still pending. Despite Lpar1(-/-) mice displaying a low bone mass phenotype, we demonstrated that bone marrow cell-induced osteoclastogenesis was reduced in Lpar1(-/-) mice but not in Lpar2(-/-) and Lpar3(-/-) animals. Expression of LPA1 was up-regulated during osteoclastogenesis, and LPA1 antagonists (Ki16425, Debio0719, and VPC12249) inhibited osteoclast differentiation. Blocking LPA1 activity with Ki16425 inhibited expression of nuclear factor of activated T-cell cytoplasmic 1 (NFATc1) and dendritic cell-specific transmembrane protein and interfered with the fusion but not the proliferation of osteoclast precursors. Similar to wild type osteoclasts treated with Ki16425, mature Lpar1(-/-) osteoclasts had reduced podosome belt and sealing zone resulting in reduced mineralized matrix resorption. Additionally, LPA1 expression markedly increased in the bone of ovariectomized mice, which was blocked by bisphosphonate treatment. Conversely, systemic treatment with Debio0719 prevented ovariectomy-induced cancellous bone loss. Moreover, intravital multiphoton microscopy revealed that Debio0719 reduced the retention of CX3CR1-EGFP(+) osteoclast precursors in bone by increasing their mobility in the bone marrow cavity. Overall, our results demonstrate that LPA1 is essential for in vitro and in vivo osteoclast activities. Therefore, LPA1 emerges as a new target for the treatment of diseases associated with excess bone loss.


Assuntos
Reabsorção Óssea/patologia , Proteínas de Membrana/metabolismo , Fatores de Transcrição NFATC/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Osteoclastos/patologia , Receptores de Ácidos Lisofosfatídicos/fisiologia , Animais , Células da Medula Óssea/patologia , Reabsorção Óssea/tratamento farmacológico , Reabsorção Óssea/genética , Diferenciação Celular/efeitos dos fármacos , Movimento Celular , Feminino , Isoxazóis/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Ácidos Oleicos/farmacologia , Organofosfatos/farmacologia , Osteoclastos/efeitos dos fármacos , Osteoclastos/metabolismo , Propionatos/farmacologia , Receptores de Ácidos Lisofosfatídicos/antagonistas & inibidores , Receptores de Ácidos Lisofosfatídicos/genética
20.
PLoS One ; 8(4): e61056, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23593389

RESUMO

UNLABELLED: Hepatocellular carcinoma (HCC) is a prevalent disease worldwide, and the majority of HCC-related deaths occur due to local invasion and distant metastasis. Cancer stem cells (CSCs) are a small subpopulation of cancer cells that have been hypothesized to be responsible for metastatic disease. Recently, we and others have identified a CSC population from human HCC cell lines and xenograft tumors characterized by their expression of CD133. However, the precise molecular mechanisms by which CD133(+) cancer stem-like cells mediate HCC metastasis have not been sufficiently analyzed. Here, we have sorted HCC cells using CD133 as a cancer stem cell (CSC) marker by magnetic-activated cell sorting (MACS) and demonstrated that the CD133(+) HCC cells not only possess greater migratory and invasive capacity in vitro but are also endowed with enhanced metastatic capacity in vivo and in human HCC specimens when compared to CD133(-) HCC cells. Gene expression analysis of the CD133(+) and CD133(-) cells of the HCC line SMMC-7721 revealed that G protein-coupled receptor 87 (GPR87) is highly expressed in CD133(+) HCC cells. In this study, we explored the role of GPR87 in the regulation of CD133 expression. We demonstrated that the overexpression of GPR87 up-regulated CD133 expression, promoted CSC-associated migratory and invasive properties in vitro, and increased tumor initiation in vivo. Conversely, silencing of GPR87 expression reduced the levels of CD133 expression. CONCLUSION: GPR87 promotes the growth and metastasis of CD133(+) cancer stem-like cells, and our findings may reveal new targets for HCC prevention or therapy.


Assuntos
Antígenos CD/imunologia , Carcinoma Hepatocelular/patologia , Divisão Celular/fisiologia , Glicoproteínas/imunologia , Neoplasias Hepáticas/patologia , Metástase Neoplásica , Células-Tronco Neoplásicas/imunologia , Peptídeos/imunologia , Receptores de Ácidos Lisofosfatídicos/fisiologia , Antígeno AC133 , Sequência de Bases , Carcinoma Hepatocelular/imunologia , Carcinoma Hepatocelular/metabolismo , Linhagem Celular Tumoral , Primers do DNA , Humanos , Neoplasias Hepáticas/imunologia , Neoplasias Hepáticas/metabolismo , Invasividade Neoplásica , Reação em Cadeia da Polimerase
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