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1.
Pharmacol Res Perspect ; 10(1): e00924, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35106949

RESUMO

Gefapixant (MK-7264) is a first-in-class, selective antagonist of the P2X3 purinergic receptor currently being investigated as a therapeutic agent for the treatment of refractory or unexplained chronic cough. In non-clinical studies, gefapixant was eliminated primarily by renal excretion of the parent drug. The objective of this study was to assess the disposition of gefapixant in humans. The absorption, metabolism, and excretion profiles of gefapixant were assessed after oral administration of a single dose of [14 C]gefapixant to six healthy adult males. Following a single-oral [14 C]gefapixant dose to healthy adult males, the mass balance was achieved, with 98.9% of the administered radioactivity recovered in urine and feces. Elimination of gefapixant occurred primarily via renal excretion of the intact drug (64%); metabolism was a minor pathway of elimination of gefapixant (12% and 2% recovered in urine and feces, respectively). Single-dose administration of [14 C]gefapixant 50 mg was generally well tolerated in healthy adult males. The fraction of the anticipated therapeutic oral dose of gefapixant absorbed is estimated to be at least 78%. Gefapixant is expected to be the major circulating drug-related material in plasma, and the majority of the dosed drug will be excreted unchanged in urine.


Assuntos
Antagonistas do Receptor Purinérgico P2X/farmacocinética , Pirimidinas/farmacocinética , Sulfonamidas/farmacocinética , Administração Oral , Adulto , Radioisótopos de Carbono , Humanos , Masculino , Antagonistas do Receptor Purinérgico P2X/administração & dosagem , Antagonistas do Receptor Purinérgico P2X/efeitos adversos , Pirimidinas/administração & dosagem , Pirimidinas/efeitos adversos , Receptores Purinérgicos P2X3/efeitos dos fármacos , Sulfonamidas/administração & dosagem , Sulfonamidas/efeitos adversos , Adulto Jovem
2.
Purinergic Signal ; 18(1): 13-59, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34757513

RESUMO

Hyperinflammation plays an important role in severe and critical COVID-19. Using inconsistent criteria, many researchers define hyperinflammation as a form of very severe inflammation with cytokine storm. Therefore, COVID-19 patients are treated with anti-inflammatory drugs. These drugs appear to be less efficacious than expected and are sometimes accompanied by serious adverse effects. SARS-CoV-2 promotes cellular ATP release. Increased levels of extracellular ATP activate the purinergic receptors of the immune cells initiating the physiologic pro-inflammatory immune response. Persisting viral infection drives the ATP release even further leading to the activation of the P2X7 purinergic receptors (P2X7Rs) and a severe yet physiologic inflammation. Disease progression promotes prolonged vigorous activation of the P2X7R causing cell death and uncontrolled ATP release leading to cytokine storm and desensitisation of all other purinergic receptors of the immune cells. This results in immune paralysis with co-infections or secondary infections. We refer to this pathologic condition as hyperinflammation. The readily available and affordable P2X7R antagonist lidocaine can abrogate hyperinflammation and restore the normal immune function. The issue is that the half-maximal effective concentration for P2X7R inhibition of lidocaine is much higher than the maximal tolerable plasma concentration where adverse effects start to develop. To overcome this, we selectively inhibit the P2X7Rs of the immune cells of the lymphatic system inducing clonal expansion of Tregs in local lymph nodes. Subsequently, these Tregs migrate throughout the body exerting anti-inflammatory activities suppressing systemic and (distant) local hyperinflammation. We illustrate this with six critically ill COVID-19 patients treated with lidocaine.


Assuntos
Trifosfato de Adenosina/metabolismo , COVID-19/imunologia , Síndrome da Liberação de Citocina/etiologia , Inflamação/etiologia , Lidocaína/uso terapêutico , Antagonistas do Receptor Purinérgico P2X/uso terapêutico , Receptores Purinérgicos/fisiologia , Anti-Inflamatórios/uso terapêutico , Cuidados Críticos , Síndrome da Liberação de Citocina/tratamento farmacológico , Humanos , Inflamação/tratamento farmacológico , Infusões Subcutâneas , Lidocaína/administração & dosagem , Lidocaína/farmacologia , Linfonodos/imunologia , Sistema Linfático/imunologia , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Modelos Imunológicos , Antagonistas do Receptor Purinérgico P2X/administração & dosagem , Antagonistas do Receptor Purinérgico P2X/farmacologia , Receptores Purinérgicos/efeitos dos fármacos , Receptores Purinérgicos P1/efeitos dos fármacos , Receptores Purinérgicos P1/fisiologia , Receptores Purinérgicos P2X7/fisiologia , Síndrome do Desconforto Respiratório/tratamento farmacológico , Síndrome do Desconforto Respiratório/etiologia , Transdução de Sinais , Linfócitos T Reguladores/imunologia
3.
Biomed Pharmacother ; 142: 112006, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34392085

RESUMO

P2X7 receptor promotes inflammatory response and neuropathic pain. New drugs capable of impairing inflammation and pain-reducing adverse effects extracted from plant extracts have been studied. Physalis angulate L. possesses traditional uses and exhibits antiparasitic, anti-inflammatory, antimicrobial, antinociceptive, antimalarial, antileishmanial, immunosuppressive, antiasthmatic. diuretic, and antitumor activities. The most representative phytochemical constituents identified with medicinal importance are the physalins and withanolides. However, the mechanism of anti-inflammatory action is scarce. Although some physalins and withanolides subtypes have anti-inflammatory activity, only four physalins subtypes (B, D, F, and G) have further studies. Therefore, we evaluated the crude ethanolic extract enriched with physalins B, D, F, and G from P. angulata leaves, a pool containing the physalins B, D, F, G, and the physalins individually, as P2X7 receptor antagonists. For this purpose, we evaluated ATP-induced dye uptake, macroscopic currents, and interleukin 1-ß (IL-1ß) in vitro. The crude extract and pool dose-dependently inhibited P2X7 receptor function. Thus, physalin B, D, F, and G individually evaluated for 5'-triphosphate (ATP)-induced dye uptake assay, whole-cell patch-clamp, and cytokine release showed distinct antagonist levels. Physalin D displayed higher potency and efficacy than physalin B, F, and G for all these parameters. In vivo mice model as ATP-induced paw edema was potently inhibited for physalin D, in contrast to physalin B, F, and G. ATP and lipopolysaccharide (LPS)-induced pleurisy in mice were reversed for physalin D treatment. Molecular modeling and computational simulation predicted the intermolecular interactions between the P2X7 receptor and physalin derivatives. In silico results indicated physalin D and F as a potent allosteric P2X7 receptor antagonist. These data confirm physalin D as a promisor source for developing a new P2X7 receptor antagonist with anti-inflammatory action.


Assuntos
Lesão Pulmonar Aguda/tratamento farmacológico , Physalis/química , Extratos Vegetais/farmacologia , Secoesteroides/farmacologia , Lesão Pulmonar Aguda/fisiopatologia , Animais , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/isolamento & purificação , Anti-Inflamatórios/farmacologia , Simulação por Computador , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Células HEK293 , Humanos , Masculino , Camundongos , Modelos Moleculares , Extratos Vegetais/administração & dosagem , Folhas de Planta , Antagonistas do Receptor Purinérgico P2X/administração & dosagem , Antagonistas do Receptor Purinérgico P2X/isolamento & purificação , Antagonistas do Receptor Purinérgico P2X/farmacologia , Receptores Purinérgicos P2X7/efeitos dos fármacos , Secoesteroides/isolamento & purificação
4.
J Chem Neuroanat ; 116: 101993, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34147620

RESUMO

OBJECTIVE: We studied the role of the P2X7 receptor on cognitive dysfunction in a mouse model of schizophrenia. METHODS: An adult mouse model was established by treatment with phencyclidine (PCP), an N-methyl-D-aspartate (NMDA) receptor antagonist. Young mice were divided into three groups: 1) the control (saline-injected) group; 2) experimental 5 mg/kg PCP-injected group; and 3) experimental 10 mg/kg PCP-injected group. The mice were subjected to the open-field and Morris water maze tests at 7 weeks. After intraperitoneal injection of the P2X7 receptor antagonist JNJ-47965567, the behaviour tests were performed again. Samples were taken after testing. The P2X7 receptor protein and mRNA expression levels were detected by immunohistochemistry, Western blotting and PCR. RESULTS: This study revealed that the infant sub-chronic PCP mice model showed severe spatial learning and memory impairment in the Morris water maze and schizophrenia-like symptoms (hypermotor behaviour) in the open-field test. The P2X7 receptor protein was highly expressed in the sub-chronic PCP mouse model and more highly expressed in the hippocampus than the prefrontal lobe. After the P2X7 receptor was blocked with JNJ-47965567, P2X7 receptor protein and mRNA expression in the frontal lobe were significantly increased, and the spatial memory impairment and hypermotor behaviour induced by PCP were reversed. CONCLUSION: PCP-induced cognitive impairment can be significantly improved by antagonizing the P2X7 receptor. Therefore, we believe that the P2X7 receptor plays an important role in the cognition of schizophrenic-like mice.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Fenciclidina/toxicidade , Antagonistas do Receptor Purinérgico P2X/administração & dosagem , Receptores Purinérgicos P2X7/metabolismo , Esquizofrenia/tratamento farmacológico , Esquizofrenia/metabolismo , Animais , Animais Recém-Nascidos , Alucinógenos/toxicidade , Injeções Subcutâneas , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Niacinamida/administração & dosagem , Niacinamida/análogos & derivados , Piperazinas/administração & dosagem , Roedores , Esquizofrenia/induzido quimicamente
5.
Biochem Pharmacol ; 187: 114472, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33587917

RESUMO

For the past three decades, our laboratory has conducted pioneering research to elucidate the complexity of purinergic signaling in the CNS, alone and in collaboration with other groups, inspired by the ground-breaking efforts of Geoffrey Burnstock. This review summarizes our contribution to understand the nucleotide receptor signaling in the CNS with a special focus on the P2X7 receptor.


Assuntos
Sistema Nervoso Central/metabolismo , Doenças Neurodegenerativas/metabolismo , Receptores Purinérgicos P2X7/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Sinalização do Cálcio/efeitos dos fármacos , Sinalização do Cálcio/fisiologia , Sistema Nervoso Central/efeitos dos fármacos , Humanos , Doenças Neurodegenerativas/tratamento farmacológico , Agonistas do Receptor Purinérgico P2X/administração & dosagem , Antagonistas do Receptor Purinérgico P2X/administração & dosagem , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia
6.
Bioorg Med Chem Lett ; 37: 127833, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33540044

RESUMO

P2X3 receptor is an ATP-gated ion channel, mainly localized on peripheral sensory neurons. Currently, several clinical trials are being conducted with P2X3 receptor antagonists for the treatment of chronic pain or cough. To identify a P2X3 lead compound, we reexamined the HTS evaluation compounds and selected dioxotriazine derivatives from which we identified a hit compound. As a result of the hit-to-lead SAR, we obtained lead compound 1 which had a moderate inhibitory effect on P2X3 receptors (IC50, 128 nM). Further improvement of the potency and PK profiles of this lead compound finally led to the selected compound 74 (P2X3 IC50, 16.1 nM; P2X2/3 IC50, 2931 nM), which demonstrated a strong analgesic effect against allodynia on oral administration in the rat partial sciatic nerve ligation model of neuropathic pain (ED50, 3.1 mg/kg).


Assuntos
Neuralgia/tratamento farmacológico , Antagonistas do Receptor Purinérgico P2X/farmacologia , Receptores Purinérgicos P2X3/metabolismo , Triazinas/farmacologia , Administração Oral , Animais , Relação Dose-Resposta a Droga , Humanos , Microssomos Hepáticos/química , Microssomos Hepáticos/metabolismo , Estrutura Molecular , Neuralgia/metabolismo , Antagonistas do Receptor Purinérgico P2X/administração & dosagem , Antagonistas do Receptor Purinérgico P2X/química , Ratos , Relação Estrutura-Atividade , Triazinas/administração & dosagem , Triazinas/química
7.
Clin Sci (Lond) ; 135(3): 495-513, 2021 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-33463682

RESUMO

Graft-versus-host disease (GVHD) is a severe inflammatory response arising from allogeneic haematopoietic stem cell transplantation. Previous studies revealed that antagonism of the P2X7 receptor with Brilliant Blue G (BBG) reduced liver GVHD but did not alter clinical GVHD in a humanised mouse model. Therefore, the present study aimed to trial a modified injection regime using more frequent dosing of BBG to improve outcomes in this model of GVHD. NOD-scid IL2Rγnull (NSG) mice were injected intraperitoneally (i.p.) with 10 × 106 human peripheral blood mononuclear cells (hPBMCs) (day 0), then daily with BBG (50 mg/kg) or saline (days 0-10). BBG significantly reduced clinical score, mortality and histological GVHD compared with saline treatment (endpoint). BBG significantly increased proportions of human regulatory T cells (Tregs) and human B cells and reduced serum human interferon-γ compared with saline treatment prior to development of clinical GVHD (day 21). To confirm the therapeutic benefit of P2X7 antagonism, NSG mice were injected i.p. with 10 × 106 hPBMCs (day 0), then daily with pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid (PPADS) (300 mg/kg) or saline (days 0-10). PPADS increased human Treg proportions compared with saline treatment (day 21), but potential clinical benefits were confounded by increased weight loss with this antagonist. To investigate the role of P2X7 antagonism on Treg survival, hPBMCs were cultured in reduced serum conditions to promote cell death. BBG increased proportions of Tregs (and B cells) compared with saline under these conditions. In conclusion, P2X7 antagonism reduces clinical and histological GVHD in a humanised mouse model corresponding to an increase in human Tregs.


Assuntos
Doença Enxerto-Hospedeiro/tratamento farmacológico , Antagonistas do Receptor Purinérgico P2X/farmacologia , Receptores Purinérgicos P2X7/efeitos dos fármacos , Corantes de Rosanilina/farmacologia , Adulto , Animais , Linfócitos B , Modelos Animais de Doenças , Feminino , Doença Enxerto-Hospedeiro/patologia , Transplante de Células-Tronco Hematopoéticas , Humanos , Leucócitos Mononucleares , Masculino , Camundongos Endogâmicos NOD , Camundongos SCID , Antagonistas do Receptor Purinérgico P2X/administração & dosagem , Fosfato de Piridoxal/administração & dosagem , Fosfato de Piridoxal/análogos & derivados , Fosfato de Piridoxal/farmacologia , Corantes de Rosanilina/administração & dosagem , Linfócitos T Reguladores/efeitos dos fármacos
8.
Biochem Pharmacol ; 187: 114408, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33444568

RESUMO

Extracellular purine and pyrimidine nucleotides produce their pharmacological effects through P2 receptors. These were first named by Geoff Burnstock in an extensive review in 1978. They were then subdivided into P2X and P2Y purinoceptors by Burnstock and Kennedy in 1985, based on applying pharmacological criteria to data generated by functional studies in smooth muscle tissues. Several other P2 subtypes, P2T, P2Z, P2U and P2D were subsequently identified in the following years, again using pharmacological criteria. The number and identity of subtypes were clarified and simplified by the cloning of seven ATP-sensitive ligand-gated ion channel subunits and eight adenine and/or uracil nucleotide-sensitive G protein-coupled receptors from 1993 onwards. The former were all classified as members of the P2X receptor family and the latter as members of the P2Y receptor family. More recently, high resolution imaging of the tertiary and quaternary structures of several P2X and P2Y receptor subtypes has provided a much greater understanding of how and where agonists and antagonists bind to the receptors and how this leads to changes in receptor conformation and activity. In addition, medicinal chemistry has produced a variety of subtype-selective agonists and antagonists, some of which are now in clinical use. This progress and success is a testimony to the foresight, intelligence, enthusiasm and drive of Geoff Burnstock, who led the field forward throughout his scientific life.


Assuntos
Trifosfato de Adenosina/metabolismo , Receptores Purinérgicos P2X/metabolismo , Receptores Purinérgicos P2Y/metabolismo , Transdução de Sinais/fisiologia , Animais , Humanos , Agonistas do Receptor Purinérgico P2X/administração & dosagem , Antagonistas do Receptor Purinérgico P2X/administração & dosagem , Agonistas do Receptor Purinérgico P2Y , Antagonistas do Receptor Purinérgico P2Y/administração & dosagem , Transdução de Sinais/efeitos dos fármacos
9.
Biochem Pharmacol ; 187: 114309, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33130129

RESUMO

Chronic pain is a debilitating condition that often occurs following peripheral tissue inflammation and nerve injury. This pain, especially neuropathic pain, is a significant clinical problem because of the ineffectiveness of clinically available drugs. Since Burnstock proposed new roles of nucleotides as neurotransmitters, the roles of extracellular ATP and P2 receptors (P2Rs) in pain signaling have been extensively studied, and ATP-P2R signaling has subsequently received much attention as it can provide clues toward elucidating the mechanisms underlying chronic pain and serve as a potential therapeutic target. This review summarizes the literature regarding the role of ATP signaling via P2X3Rs (as well as P2X2/3Rs) in primary afferent neurons and via P2X4Rs and P2X7Rs in spinal cord microglia in chronic pain, and discusses their respective therapeutic potentials.


Assuntos
Dor Crônica/metabolismo , Nociceptividade/fisiologia , Receptores Purinérgicos P2X3/metabolismo , Receptores Purinérgicos P2X4/metabolismo , Receptores Purinérgicos P2X7/metabolismo , Transdução de Sinais/fisiologia , Trifosfato de Adenosina/metabolismo , Animais , Dor Crônica/tratamento farmacológico , Humanos , Nociceptividade/efeitos dos fármacos , Agonistas do Receptor Purinérgico P2X/administração & dosagem , Antagonistas do Receptor Purinérgico P2X/administração & dosagem , Células Receptoras Sensoriais/efeitos dos fármacos , Células Receptoras Sensoriais/metabolismo , Transdução de Sinais/efeitos dos fármacos , Medula Espinal/efeitos dos fármacos , Medula Espinal/metabolismo
10.
Biochem Pharmacol ; 187: 114385, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33359010

RESUMO

Adenosine triphosphate (ATP) is a molecule that on one hand plays a central role in cellular energetics and which on the other is a ubiquitous signaling molecule when released into the extracellular media. Extracellular ATP accumulates in inflammatory environments where it acts as a damage-associated molecular pattern and activates the purinergic P2X receptor 7 (P2X7) in immune cells. P2X7 receptor activation induces the formation of the nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing 3 (NLRP3) inflammasome and the activation of the inflammatory caspase-1. Caspase-1 causes an inflammatory type of cell death called pyroptosis through the release of pro-inflammatory cytokines and intracellular content. Consequently, intense research efforts have been devoted to the design of novel anti-inflammatory therapies, focusing in particular on the P2X7 receptor and the NLRP3 pathway and the introduction of new blocking molecules in early phase clinical trials.


Assuntos
Trifosfato de Adenosina/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Receptores Purinérgicos P2X7/metabolismo , Animais , Humanos , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/antagonistas & inibidores , Agonistas do Receptor Purinérgico P2X/administração & dosagem , Antagonistas do Receptor Purinérgico P2X/administração & dosagem , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia
11.
Biochem Pharmacol ; 187: 114350, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33253643

RESUMO

It is increasingly appreciated that ion channels have a crucial role in tumors, either as promoters of cancer cell growth, or modulators of immune cell functions, or both. Among ion channels, P2X receptors have a special status because they are gated by ATP, a common and abundant component of the tumor microenvironment. Furthermore, one P2X receptor, i.e. P2X7, may also function as a conduit for ATP release, thus fuelling the increased extracellular ATP level in the tumor interstitium. These findings show that P2X receptors and extracellular ATP are indissoluble partners and key regulators of tumor growth, and suggest the exploitation of the extracellular ATP-P2X partnership to develop innovative therapeutic approaches to cancer.


Assuntos
Progressão da Doença , Neoplasias/metabolismo , Receptores Purinérgicos P2X/metabolismo , Microambiente Tumoral/fisiologia , Trifosfato de Adenosina/imunologia , Trifosfato de Adenosina/metabolismo , Animais , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/imunologia , Agonistas do Receptor Purinérgico P2X/administração & dosagem , Antagonistas do Receptor Purinérgico P2X/administração & dosagem , Receptores Purinérgicos P2X/imunologia , Microambiente Tumoral/efeitos dos fármacos
12.
Dis Model Mech ; 13(10)2020 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-33174532

RESUMO

Neuroinflammation is one of the main physiopathological mechanisms of amyotrophic lateral sclerosis (ALS), produced by the chronic activation of microglia in the CNS. This process is triggered by the persistent activation of the ATP-gated P2X7 receptor (P2RX7, hereafter referred to as P2X7R). The present study aimed to evaluate the effects of the chronic treatment with the P2X7R antagonist JNJ-47965567 in the development and progression of ALS in the SOD1G93A murine model. SOD1G93A mice were intraperitoneally (i.p.) injected with either 30 mg/kg of JNJ-47965567 or vehicle 4 times per week, from pre-onset age (here, postnatal day 60; P60) until study endpoint. Body weight, motor coordination, phenotypic score, disease onset and survival were measured throughout the study, and compared between vehicle- and drug-injected groups. Treatment with the P2X7R antagonist JNJ-47965567 delayed disease onset, reduced body weight loss and improved motor coordination and phenotypic score in female SOD1G93A mice, although it did not increase lifespan. Interestingly, neither beneficial nor detrimental effects were observed in males in any of the analyzed parameters. Treatment did not affect motor neuron survival or ChAT, Iba-1 and P2X7R protein expression in endpoint individuals of mixed sexes. Overall, chronic administration of JNJ-47965567 for 4 times per week to SOD1G93A mice from pre-onset stage altered disease progression in female individuals while it did not have any effect in males. Our results suggest a partial, yet important, effect of P2X7R in the development and progression of ALS.


Assuntos
Esclerose Lateral Amiotrófica/tratamento farmacológico , Esclerose Lateral Amiotrófica/fisiopatologia , Progressão da Doença , Atividade Motora , Niacinamida/análogos & derivados , Piperazinas/administração & dosagem , Piperazinas/uso terapêutico , Antagonistas do Receptor Purinérgico P2X/administração & dosagem , Antagonistas do Receptor Purinérgico P2X/uso terapêutico , Receptores Purinérgicos P2X7/metabolismo , Animais , Sobrevivência Celular/efeitos dos fármacos , Determinação de Ponto Final , Feminino , Humanos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Atividade Motora/efeitos dos fármacos , Neurônios Motores/efeitos dos fármacos , Neurônios Motores/patologia , Niacinamida/administração & dosagem , Niacinamida/química , Niacinamida/farmacologia , Niacinamida/uso terapêutico , Piperazinas/química , Piperazinas/farmacologia , Antagonistas do Receptor Purinérgico P2X/química , Antagonistas do Receptor Purinérgico P2X/farmacologia , Teste de Desempenho do Rota-Rod , Análise de Sobrevida , Redução de Peso/efeitos dos fármacos
13.
Neurotherapeutics ; 17(3): 826-838, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33009633

RESUMO

Current therapies for the treatment of chronic pain provide inadequate relief for millions of suffering patients, demonstrating the need for better therapies that will treat pain effectively and improve the quality of patient's lives. Better understanding of the mechanisms that mediate chronic pain is critical for developing drugs with improved clinical outcomes. Adenosine triphosphate (ATP) is a key modulator in nociceptive pathways. Release of ATP from injured tissue or sympathetic efferents has sensitizing effects on sensory neurons in the periphery, and presynaptic vesicular release of ATP from the central terminals can increase glutamate release thereby potentiating downstream central sensitization mechanisms, a condition thought to underlie many chronic pain conditions. The purinergic receptors on sensory nerves primarily responsible for ATP signaling are P2X3 and P2X2/3. Selective knockdown experiments, or inhibition with small molecules, demonstrate P2X3-containing receptors are key targets to modulate nociceptive signals. Preclinical studies have identified that P2X3-containing receptors are critical for sensory transduction for bladder function, and clinical studies have shown promise in treatment for bladder pain and pain associated with osteoarthritis. Further clinical characterization of antagonists to P2X3-containing receptors may lead to improved therapies in the treatment of chronic pain.


Assuntos
Dor Crônica/tratamento farmacológico , Dor Crônica/metabolismo , Sistemas de Liberação de Medicamentos/métodos , Antagonistas do Receptor Purinérgico P2X/metabolismo , Receptores Purinérgicos P2X3/metabolismo , Trifosfato de Adenosina/antagonistas & inibidores , Trifosfato de Adenosina/metabolismo , Animais , Humanos , Antagonistas do Receptor Purinérgico P2X/administração & dosagem , Células Receptoras Sensoriais/efeitos dos fármacos , Células Receptoras Sensoriais/metabolismo , Resultado do Tratamento
14.
Am J Physiol Regul Integr Comp Physiol ; 319(2): R223-R232, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32609538

RESUMO

Purinergic 2X (P2X) receptors on the endings of group III and IV afferents play a role in evoking the exercise pressor reflex. Particular attention has been paid to P2X3 receptors because their blockade in the periphery attenuated this reflex. In contrast, nothing is known about the role played by P2X receptors in the spinal cord in evoking the exercise pressor reflex in rats. P2X7 receptors, in particular, may be especially important in this regard because they are found in abundance on spinal glial cells and may communicate with neurons to effect reflexes controlling cardiovascular function. Consequently, we investigated the role played by spinal P2X7 receptors in evoking the exercise pressor reflex in decerebrated rats. We found that intrathecal injection of the P2X7 antagonist brilliant blue G (BBG) attenuated the exercise pressor reflex (blood pressure index: 294 ± 112 mmHg·s before vs. 7 ± 32 mmHg·s after; P < 0.05). Likewise, intrathecal injection of minocycline, which inhibits microglial cell output, attenuated the reflex. In contrast, intrathecal injection of BBG did not attenuate the pressor response evoked by intracarotid injection of sodium cyanide, a maneuver that stimulated carotid chemoreceptors. Moreover, injections of BBG either into the arterial supply of the contracting hindlimb muscles or into the jugular vein did not attenuate the exercise pressor reflex. Our findings support the hypothesis that P2X7 receptors on microglial cells within the spinal cord play a role in evoking the exercise pressor reflex.


Assuntos
Pressão Sanguínea/efeitos dos fármacos , Condicionamento Físico Animal , Antagonistas do Receptor Purinérgico P2X/administração & dosagem , Reflexo/efeitos dos fármacos , Corantes de Rosanilina/administração & dosagem , Animais , Estado de Descerebração/fisiopatologia , Injeções Espinhais , Masculino , Minociclina/farmacologia , Ratos , Ratos Sprague-Dawley
15.
J Psychopharmacol ; 34(9): 1030-1042, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32248747

RESUMO

BACKGROUND: This is the first report of the pharmacodynamic (PD) effects of the selective, potent and brain-penetrant P2X7 receptor (P2X7R) antagonist JNJ-54175446. Activation of the P2X7R, an adenosine triphosphate-gated ion channel, leads to the production of pro-inflammatory cytokines, which have been linked to neuroinflammation and play a role in the pathogenesis of mood disorders. Previous clinical studies with JNJ-54175446 demonstrated peripheral target engagement of JNJ-54175446 by assessing ex vivo lipopolysaccharide (LPS)-stimulated cytokine production. Blood-brain barrier penetration and a clear dose-receptor occupancy relationship was demonstrated using positron emission tomography. AIMS: The objectives of this double-blind, placebo-controlled, translational study were to assess the safety and tolerability of administering multiple doses of JNJ-54175446 and to explore its PD effects using a dexamphetamine challenge. METHODS: Subjects (N = 64) were randomised to either JNJ-54175446 (50-450 mg; n = 48) or placebo (n = 16) and underwent a baseline oral 20 mg dexamphetamine challenge followed by 11 consecutive days q.d. dosing with JNJ-54175446/placebo and a randomised crossover dexamphetamine/placebo challenge. RESULTS: At all doses tested, JNJ-54175446 was well tolerated and suppressed the ex vivo LPS-induced release of cytokines. At doses ⩾100 mg, JNJ-54175446 attenuated dexamphetamine-induced increases in locomotion and enhanced the mood-elevating effects of dexamphetamine, suggesting that a dose that is approximately twice as high is needed to obtain a central PD response compared to the dose needed for maximum peripheral occupancy. CONCLUSION: Overall, the observed pharmacological profile of JNJ-54175446 in the dexamphetamine challenge paradigm is compatible with a potential mood-modulating effect.


Assuntos
Estimulantes do Sistema Nervoso Central/farmacologia , Dextroanfetamina/farmacologia , Antagonistas do Receptor Purinérgico P2X/farmacologia , Piridinas/farmacologia , Triazóis/farmacologia , Adolescente , Adulto , Estimulantes do Sistema Nervoso Central/administração & dosagem , Transtorno Depressivo Maior/tratamento farmacológico , Dextroanfetamina/administração & dosagem , Método Duplo-Cego , Eletroencefalografia , Humanos , Inflamação/tratamento farmacológico , Masculino , Antagonistas do Receptor Purinérgico P2X/administração & dosagem , Antagonistas do Receptor Purinérgico P2X/efeitos adversos , Antagonistas do Receptor Purinérgico P2X/farmacocinética , Piridinas/administração & dosagem , Piridinas/efeitos adversos , Piridinas/farmacocinética , Pesquisa Translacional Biomédica , Triazóis/administração & dosagem , Triazóis/efeitos adversos , Triazóis/farmacocinética , Adulto Jovem
16.
Lancet Respir Med ; 8(8): 775-785, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32109425

RESUMO

BACKGROUND: Gefapixant is a P2X3 receptor antagonist that has shown promise for the treatment of refractory and unexplained chronic cough. The aim of this study was to evaluate the efficacy of gefapixant compared with placebo after 12 weeks of treatment for refractory chronic cough or unexplained chronic cough. METHODS: We did a 12-week, phase 2b, randomised, double-blind, placebo-controlled study in patients with refractory chronic cough or unexplained chronic cough aged 18-80 years who were recruited from 44 primarily outpatient pulmonologist or allergist sites in the UK and the USA. Eligible patients had refractory or unexplained chronic cough lasting 1 year or longer, no radiographic chest abnormality, and 40 mm or more on a 100-mm cough severity visual analogue scale at enrolment. Patients were randomly assigned to receive placebo or one of three doses (7·5 mg, 20 mg, or 50 mg) of oral gefapixant twice daily, every day, for 84 days; visits to investigative sites were on days 1, 28, 42, 56, 70, 84, and 85. The randomisation schedule was computer generated using a permuted block algorithm by Advance Research Associates (Santa Clara, CA, USA). Patients and all personnel involved in the conduct and interpretation of the study were masked to treatment assignment. The primary endpoint was placebo-adjusted change from baseline in awake cough frequency after 12 weeks, assessed in the full analysis set, which is a subset of the intention-to-treat population. Adverse events were monitored and safety was evaluated in all patients receiving one or more doses of study drug. This trial is registered with ClinicalTrials.gov, NCT02612610. FINDINGS: Between Dec 21, 2015, and July 26, 2016, 253 patients were randomly assigned to placebo (n=63), gefapixant 7·5 mg (n=64), gefapixant 20 mg (n=63), or gefapixant 50 mg (n=63) twice daily. The mean age of patients was 60·2 (SD 9·9) years and 193 (76%) were women. At 12 weeks, patients' geometric mean awake cough frequency was 18·2 coughs per h (geometric SD 3·1) with placebo, and 14·5 coughs per h (3·7) with 7·5 mg, 12·0 coughs per h (4·2) with 20 mg, and 11·3 coughs per h (2·8) with 50 mg gefapixant. Estimated percentage change relative to placebo was -22·0% (-41·8 to 4·6; p=0·097) with 7·5 mg, -22·2% (-42·0 to 4·3; p=0·093) with 20 mg, and -37·0% (95% CI -53·3 to -14·9; p=0·0027) with 50 mg gefapixant. Dysgeusia was the most common adverse event, occurring in three (5%) patients given placebo, six (10%) given 7·5 mg gefapixant, 21 (33%) given 20 mg gefapixant, and 30 (48%) given 50 mg gefapixant. INTERPRETATION: Targeting purinergic receptor P2X3 with gefapixant at a dose of 50 mg twice daily significantly reduced cough frequency in patients with refractory chronic cough or unexplained chronic cough after 12 weeks of treatment compared with placebo. Further development of gefapixant is warranted for the treatment of chronic cough. FUNDING: Afferent Pharmaceuticals (acquired by Merck & Co., Inc., Kenilworth, NJ, USA).


Assuntos
Doença Crônica/tratamento farmacológico , Tosse/tratamento farmacológico , Antagonistas do Receptor Purinérgico P2X/administração & dosagem , Pirimidinas/administração & dosagem , Sulfonamidas/administração & dosagem , Adulto , Idoso , Relação Dose-Resposta a Droga , Método Duplo-Cego , Disgeusia/induzido quimicamente , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Antagonistas do Receptor Purinérgico P2X/efeitos adversos , Pirimidinas/efeitos adversos , Sulfonamidas/efeitos adversos , Reino Unido , Estados Unidos , Adulto Jovem
18.
J Med Chem ; 63(5): 2074-2094, 2020 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-31525963

RESUMO

This report deals with the design, the synthesis, and the pharmacological evaluation of pyroglutamide-based P2X7 antagonists. A dozen were shown to possess improved properties, among which inhibition of YO-PRO-1/TO-PRO-3 uptake and IL1ß release upon BzATP activation of the receptor and dampening signs of DSS-induced colitis on mice, in comparison with reference antagonist GSK1370319A. Docking study and biological evaluation of synthesized compounds has highlighted new SAR, and low toxicity profiles of pyroglutamides herein described are clues for the finding of a usable h-P2X7 antagonist drug. Such a drug would raise the hope for a cure to many P2X7-dependent pathologies, including inflammatory, neurological, and immune diseases.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Doenças Inflamatórias Intestinais/tratamento farmacológico , Doenças Inflamatórias Intestinais/metabolismo , Antagonistas do Receptor Purinérgico P2X/administração & dosagem , Antagonistas do Receptor Purinérgico P2X/metabolismo , Receptores Purinérgicos P2X7/metabolismo , Animais , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Sulfato de Dextrana/toxicidade , Feminino , Células HEK293 , Humanos , Doenças Inflamatórias Intestinais/induzido quimicamente , Camundongos , Camundongos Endogâmicos C57BL
19.
Clin Transl Sci ; 13(2): 309-317, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31642608

RESUMO

Positron emission tomography (PET) provides useful information in target engagement or receptor occupancy in the brain for central nervous system (CNS) drug development, however, dose selection for human PET studies is challenging and largely empirical. Here, we describe a translational pharmacokinetic/pharmacodynamic (PK/PD) modeling work to inform dose selection for a human PET study of JNJ-54175446, a CNS-penetrating P2X7 receptor antagonist. Models were developed using data on monkey brain occupancy and plasma drug exposures from a monkey PET study and early human clinical studies that provided data on drug exposures and human ex vivo-stimulated peripheral interleukin (IL)-1ß release. The observed plasma PK of JNJ-54175446 in human was adequately described by a one-compartment model with parallel zero-order and first-order absorption and first-order elimination. An exposure-occupancy model was extrapolated from monkey to human assuming a similar unbound potency (all other model parameters remained unchanged). This model was then used to simulate human brain occupancy to guide human PET study dose selection, together with the human population PK model. The corroboration of model predicted occupancy by the observed occupancy data from the human PET study supports the use of a monkey as a predictive model for human PET target engagement. Potency estimate for brain occupancy was generally comparable to that for the suppression of the provoked peripheral IL-1ß release ex vivo, indicating that blood IL-1ß release may be used as a surrogate of central occupancy for JNJ-54175446. Translational PK/PD modeling approach could be used for selecting optimal doses for human PET and other clinical studies.


Assuntos
Tomografia por Emissão de Pósitrons , Antagonistas do Receptor Purinérgico P2X/farmacocinética , Piridinas/farmacocinética , Compostos Radiofarmacêuticos/farmacocinética , Receptores Purinérgicos P2X7/metabolismo , Triazóis/farmacocinética , Adolescente , Adulto , Idoso , Animais , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Ensaios Clínicos Fase I como Assunto , Simulação por Computador , Conjuntos de Dados como Assunto , Relação Dose-Resposta a Droga , Desenvolvimento de Medicamentos/métodos , Feminino , Radioisótopos de Flúor/administração & dosagem , Humanos , Interleucina-1beta/metabolismo , Macaca mulatta , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Antagonistas do Receptor Purinérgico P2X/administração & dosagem , Piridinas/administração & dosagem , Cintilografia , Compostos Radiofarmacêuticos/administração & dosagem , Ensaios Clínicos Controlados Aleatórios como Assunto , Triazóis/administração & dosagem , Adulto Jovem
20.
Brain Res Bull ; 155: 19-28, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31778766

RESUMO

Neuropathic Pain (NPP) is caused by direct or indirect damage to the nervous system and is a common symptom of many diseases. Clinically, drugs are usually used to suppress pain, such as (lidocaine, morphine, etc.), but the effect is short-lived, poor analgesia, and there are certain dependence and side effects. Therefore, the investigation of the treatment of NPP has become an urgent problem in medical, attracting a lot of research attention. P2X7 is dependent on Adenosine triphosphate (ATP) ion channel receptors and has dual functions for the development of nerve damage and pain. In this review, we explored the link between the P2X7 receptor (P2X7R) and NPP, providing insight into the P2X7R and NPP, discussing the pathological mechanism of P2 X7R in NPP and the biological characteristics of P2X7R antagonist inhibiting its over-expression for the targeted therapy of NPP.


Assuntos
Encéfalo/fisiopatologia , Neuralgia/fisiopatologia , Receptores Purinérgicos P2X7/fisiologia , Trifosfato de Adenosina/fisiologia , Animais , Humanos , Inflamação/fisiopatologia , Microglia/fisiologia , Neuralgia/tratamento farmacológico , Antagonistas do Receptor Purinérgico P2X/administração & dosagem , Transdução de Sinais/efeitos dos fármacos
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