RESUMO
Two heterozygous missense variants (G1 and G2) of Apolipoprotein L1 (APOL1) found in individuals of recent African ancestry can attenuate the severity of infection by some forms of Trypanosoma brucei. However, these two variants within a broader African haplotype also increase the risk of kidney disease in Americans of African descent. Although overexpression of either variant G1 or G2 causes multiple pathogenic changes in cultured cells and transgenic mouse models, the mechanism(s) promoting kidney disease remain unclear. Human serum APOL1 kills trypanosomes through its cation channel activity, and cation channel activity of recombinant APOL1 has been reconstituted in lipid bilayers and proteoliposomes. Although APOL1 overexpression increases whole cell cation currents in HEK-293 cells, the ion channel activity of APOL1 has not been assessed in glomerular podocytes, the major site of APOL1-associated kidney diseases. We characterize APOL1-associated whole cell and on-cell cation currents in HEK-293 T-Rex cells and demonstrate partial inhibition of currents by anti-APOL antibodies. We detect in primary human podocytes a similar cation current inducible by interferon-γ (IFNγ) and sensitive to inhibition by anti-APOL antibody as well as by a fragment of T. brucei Serum Resistance-Associated protein (SRA). CRISPR knockout of APOL1 in human primary podocytes abrogates the IFNγ-induced, antibody-sensitive current. Our novel characterization in HEK-293 cells of heterologous APOL1-associated cation conductance inhibited by anti-APOL antibody and our documentation in primary human glomerular podocytes of endogenous IFNγ-stimulated, APOL1-mediated, SRA and anti-APOL-sensitive ion channel activity together support APOL1-mediated channel activity as a therapeutic target for treatment of APOL1-associated kidney diseases.
Assuntos
Nefropatias , Podócitos , Camundongos , Animais , Humanos , Podócitos/metabolismo , Apolipoproteína L1/genética , Apolipoproteína L1/metabolismo , Células HEK293 , Nefropatias/metabolismo , Camundongos Transgênicos , Canais Iônicos/metabolismoRESUMO
The central amygdala (CeA) is important for fear responses to discrete cues. Recent findings indicate that the CeA also contributes to states of sustained apprehension that characterize anxiety, although little is known about the neural circuitry involved. The stress neuropeptide corticotropin releasing factor (CRF) is anxiogenic and is produced by subpopulations of neurons in the lateral CeA and the dorsolateral bed nucleus of the stria terminalis (dlBST). Here we investigated the function of these CRF neurons in stress-induced anxiety using chemogenetics in male rats that express Cre recombinase from a Crh promoter. Anxiety-like behavior was mediated by CRF projections from the CeA to the dlBST and depended on activation of CRF1 receptors and CRF neurons within the dlBST. Our findings identify a CRFCeAâCRFdlBST circuit for generating anxiety-like behavior and provide mechanistic support for recent human and primate data suggesting that the CeA and BST act together to generate states of anxiety.SIGNIFICANCE STATEMENT Anxiety is a negative emotional state critical to survival, but persistent, exaggerated apprehension causes substantial morbidity. Identifying brain regions and neurotransmitter systems that drive anxiety can help in developing effective treatment. Much evidence in rodents indicates that neurons in the bed nucleus of the stria terminalis (BST) generate anxiety-like behaviors, but more recent findings also implicate neurons of the CeA. The neuronal subpopulations and circuitry that generate anxiety are currently subjects of intense investigation. Here we show that CeA neurons that release the stress neuropeptide corticotropin-releasing factor (CRF) drive anxiety-like behaviors in rats via a pathway to dorsal BST that activates local BST CRF neurons. Thus, our findings identify a CeAâBST CRF neuropeptide circuit that generates anxiety-like behavior.
Assuntos
Tonsila do Cerebelo/fisiopatologia , Ansiedade/fisiopatologia , Hormônio Liberador da Corticotropina/genética , Rede Nervosa/fisiopatologia , Animais , Ansiedade/psicologia , Comportamento Animal , Corticosterona/metabolismo , Relações Interpessoais , Masculino , Neurônios/fisiologia , Ratos , Ratos Wistar , Receptores de Hormônio Liberador da Corticotropina/metabolismo , Núcleos Septais/fisiopatologia , Estresse Psicológico/fisiopatologia , Estresse Psicológico/psicologiaRESUMO
Binge eating disorder is an addiction-like disorder characterized by recurrent, excessive food consumption within discrete periods of time, and it has been linked to increased trait impulsivity. Within impulsivity components, while impulsive action was shown to predict binge-like and addictive-like eating, the role of impulsive choice is instead unknown. The goal of this study was to determine if impulsive choice predicted, or was altered by binge-like eating of a sugary, highly palatable diet. We utilized a modified adjusting delay task procedure in free-fed rats to assess impulsive choice behavior, that is. the tendency to respond for a larger, delayed reward over a lesser, immediate reward. We found that baseline impulsive choice was not a predictor of binge-like eating in 1-h sessions of palatable diet operant self-administration. Furthermore, binge-like eating of the same palatable diet had no effect on later impulsive choice behavior. Thus, our data suggest that, unlike impulsive action, impulsive choice behavior does not predict binge-like eating in rats.
Assuntos
Transtorno da Compulsão Alimentar/diagnóstico , Transtorno da Compulsão Alimentar/fisiopatologia , Comportamento de Escolha/fisiologia , Comportamento Impulsivo/fisiologia , Animais , Condicionamento Operante/fisiologia , Desvalorização pelo Atraso , Modelos Animais de Doenças , Comportamento Alimentar , Masculino , Valor Preditivo dos Testes , Ratos , Ratos Wistar , Recompensa , Resposta de SaciedadeRESUMO
The prevalence of eating disorders and obesity in western societies is epidemic and increasing in severity. Preclinical research has focused on the development of animal models that can mimic the maladaptive patterns of food intake observed in certain forms of eating disorders and obesity. This study was aimed at characterizing a recently established model of palatable diet alternation in female rats. For this purpose, females rats were fed either continuously with a regular chow diet (Chow/Chow) or intermittently with a regular chow diet for 2 days and a palatable, high-sucrose diet for 1 day (Chow/Palatable). Following diet cycling, rats were administered rimonabant (0, 0.3, 1, 3 mg/kg intraperitoneally) during access to either palatable diet or chow diet and were assessed for food intake and body weight. Finally, rats were pretreated with rimonabant (0, 3 mg/kg, intraperitoneally) and tested in the elevated plus maze during withdrawal from the palatable diet. Female rats with alternating access to palatable food cycled their intake, overeating during access to the palatable diet and undereating upon returning to the regular chow diet. Rimonabant treatment resulted in increased chow hypophagia and anxiety-like behavior in Chow/Palatable rats. No effect of drug treatment was observed on the compulsive eating of palatable food in the diet-cycled rats. The results of this study suggest that withdrawal from alternating access to the palatable diet makes individuals vulnerable to the anxiogenic effects of rimonabant and provides etiological factors potentially responsible for the emergence of severe psychiatric side-effects following rimonabant treatment in obese patients.
Assuntos
Ansiedade/induzido quimicamente , Antagonistas de Receptores de Canabinoides/farmacologia , Ingestão de Alimentos/efeitos dos fármacos , Piperidinas/farmacologia , Pirazóis/farmacologia , Animais , Comportamento Animal/efeitos dos fármacos , Antagonistas de Receptores de Canabinoides/administração & dosagem , Sacarose Alimentar/administração & dosagem , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Transtornos da Alimentação e da Ingestão de Alimentos/induzido quimicamente , Feminino , Aprendizagem em Labirinto/efeitos dos fármacos , Piperidinas/administração & dosagem , Pirazóis/administração & dosagem , Ratos , Ratos Wistar , Receptor CB1 de Canabinoide/antagonistas & inibidores , RimonabantoRESUMO
Binge eating disorder is an addiction-like disorder characterized by excessive food consumption within discrete periods of time. This study was aimed at understanding the role of the opioid system within the medial prefrontal cortex (mPFC) in the consummatory and motivational aspects of binge-like eating. For this purpose, we trained male rats to obtain either a sugary, highly palatable diet (Palatable rats) or a chow diet (Chow rats) for 1 hour/day. We then evaluated the effects of the opioid receptor antagonist, naltrexone, given either systemically or site-specifically into the nucleus accumbens (NAcc) or the mPFC on a fixed ratio 1 (FR1) and a progressive ratio schedule of reinforcement for food. Finally, we assessed the expression of the genes proopiomelanocortin (POMC), pro-dynorphin (PDyn) and pro-enkephalin (PEnk), coding for the opioids peptides in the NAcc and the mPFC in both groups. Palatable rats rapidly escalated their intake by four times. Naltrexone, when administered systemically and into the NAcc, reduced FR1 responding for food and motivation to eat under a progressive ratio in both Chow and Palatable rats; conversely, when administered into the mPFC, the effects were highly selective for binge eating rats. Furthermore, we found a twofold increase in POMC and a â¼50% reduction in PDyn gene expression in the mPFC of Palatable rats, when compared to control rats; however, no changes were observed in the NAcc. Our data suggest that neuroadaptations of the opioid system in the mPFC occur following intermittent access to highly palatable food, which may be responsible for the development of binge-like eating.
Assuntos
Transtorno da Compulsão Alimentar/prevenção & controle , Comportamento Alimentar/efeitos dos fármacos , Naltrexona/farmacologia , Peptídeos Opioides/fisiologia , Córtex Pré-Frontal/efeitos dos fármacos , Análise de Variância , Animais , Condicionamento Operante , Modelos Animais de Doenças , Masculino , Motivação/efeitos dos fármacos , Antagonistas de Entorpecentes/farmacologia , Ratos , Ratos Wistar , Reforço PsicológicoRESUMO
Although combination regimens have improved outcomes over monotherapy in chronic lymphocytic leukemia (CLL), patients eventually relapse. Combined fludarabine, cyclophosphamide, and monoclonal anti-CD52 antibody alemtuzumab (FCC) provided synergistic cytotoxicity with effective clearing of minimal residual disease. This phase 2 study determined FCC efficacy and safety in relapsed/refractory CD52(+) B-CLL after ≥ 1 line of treatment. From January 2005 through June 2008, up to 6 courses of oral fludarabine 40 mg/m² per day, oral cyclophosphamide 250 mg/m² per day, and subcutaneous alemtuzumab (Mab-Campath) 10 mg (increased to 20 mg after first 10-patient cohort) were administered days 1 to 3 every 28 days. The primary objective was overall response rate (ORR); secondary objectives included response duration, time to disease progression, and safety and tolerability. ORR was 67% in 43 patients; 30% achieved complete response. ORR significantly improved with 1 versus ≥ 2 prior therapies (P = .018), and without versus with previous monoclonal antibody treatment (P = .003). Median progression-free survival was 24.4 months, not reached in patients achieving complete response. Median overall survival was 33.6 months. Myelosuppression was the most common adverse event, with a low percentage of cytomegalovirus reactivations and manageable infections. However, close vigilance of opportunistic infections is warranted. FCC provides effective immunotherapy in relapsed/refractory CLL, including in patients with poor-risk prognostic factors.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Leucemia Linfocítica Crônica de Células B/prevenção & controle , Administração Oral , Adulto , Idoso , Alemtuzumab , Anticorpos Monoclonais Humanizados/administração & dosagem , Anticorpos Monoclonais Humanizados/efeitos adversos , Anticorpos Antineoplásicos/administração & dosagem , Anticorpos Antineoplásicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Ciclofosfamida/administração & dosagem , Ciclofosfamida/efeitos adversos , Intervalo Livre de Doença , Feminino , Humanos , Injeções Subcutâneas , Leucemia Linfocítica Crônica de Células B/mortalidade , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Recidiva , Taxa de Sobrevida , Fatores de Tempo , Vidarabina/administração & dosagem , Vidarabina/efeitos adversos , Vidarabina/análogos & derivadosRESUMO
Plerixafor, a CXCR4 antagonist, induces the rapid release of hematopoietic progenitor stem cells from the bone marrow into peripheral blood; it is approved for autologous hematopoietic progenitor stem cell mobilization in multiple myeloma and non-Hodgkin's lymphoma patients. We report the case of a 34-year-old patient with metastatic testicular embryonal carcinoma who was extensively and in vain pretreated with chemotherapy and failed to mobilize an adequate number of hematopoietic progenitor stem cells following high-dose chemotherapy, with the support of granulocyte colony-stimulating factors. After a cycle of high-dose cyclophosphamide associated with granulocyte colony-stimulating factors, plerixafor was administered to the patient, with the clinical evidence of an increase in hematopoietic progenitor stem cells in the peripheral blood. The patient achieved a complete engraftment following two cycles of high-dose chemotherapy (paclitaxel, ifosfamide, carboplatin, etoposide), with the support of hematopoietic progenitor stem cells; the patient showed discrete tolerability to the treatment. At biochemical control, the ß-human chorionic gonadotropin value decreased from 86 to less than 1.2 mUI/ml and total body PET-CT scan showed a complete response to chemotherapy. According to this experience, we believe that in patients with advanced germ cell cancer, it is essential to explore the possibility of the use of high-dose chemotherapy to induce a stable and permanent response; in this context, plerixafor, with the support of granulocyte colony-stimulating factors, may be an innovative option for satisfactory mobilization during high-dose chemotherapy protocols.
Assuntos
Compostos Heterocíclicos/uso terapêutico , Neoplasias Embrionárias de Células Germinativas/terapia , Receptores CXCR4/antagonistas & inibidores , Transplante de Células-Tronco/métodos , Neoplasias Testiculares/terapia , Adulto , Antineoplásicos/administração & dosagem , Benzilaminas , Ciclamos , Ciclofosfamida/uso terapêutico , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Células-Tronco Hematopoéticas/efeitos dos fármacos , Compostos Heterocíclicos/administração & dosagem , Humanos , Imunossupressores/uso terapêutico , MasculinoRESUMO
Alcohol use disorders (AUD) have a strong component of heritability; however, the neurobiological mechanisms mediating the propensity to consume excessive amounts of alcohol are still not well understood. Pituitary adenylate cyclase-activating polypeptide (PACAP), a highly conserved neuropeptide which exerts its effects mainly through the PAC1 receptor (PAC1R), has been suggested to be one of the mediators of the effects of drugs of abuse and alcohol. Here, we investigated the role of the PACAP/PAC1R system in excessive alcohol drinking in alcohol-preferring rats, an established animal model of AUD. Intracerebroventricular (i.c.v.) administration of the PAC1R antagonist PACAP(6-38) blocked excessive alcohol drinking and motivation to drink in Sardinian alcohol-preferring (Scr:sP) rats, without affecting water, saccharin, or sucrose intake. Notably, PACAP(6-38) did not affect ethanol responding in outbred Wistar rats. PACAP(6-38) also significantly reduced alcohol-seeking behavior under a second-order schedule of reinforcement. Using immunohistochemistry, a significant increase in the number of PAC1R positive cells was observed selectively in the nucleus accumbens (NAcc) Core of Scr:sP rats, compared to Wistar rats, following alcohol drinking. Finally, excessive drinking in Scr:sP rats was suppressed by intra-NAcc Core, but not intra-NAcc Shell, PACAP(6-38), as well as by virally-mediated PAC1R knockdown in the NAcc Core. The present study shows that hyperactivity of the PACAP/PAC1R system specifically in the NAcc Core mediates excessive drinking of alcohol-preferring rats, and indicates that this system may represent a novel target for the treatment of AUD.
Assuntos
Consumo de Bebidas Alcoólicas , Alcoolismo , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase , Receptores de Polipeptídeo Hipofisário Ativador de Adenilato Ciclase , Consumo de Bebidas Alcoólicas/tratamento farmacológico , Consumo de Bebidas Alcoólicas/metabolismo , Alcoolismo/tratamento farmacológico , Alcoolismo/metabolismo , Animais , Núcleo Accumbens/metabolismo , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/farmacologia , Ratos , Ratos Wistar , Receptores de Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/antagonistas & inibidores , Receptores de Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/metabolismoRESUMO
Emerging evidence indicates that astrogliosis is involved in the pathogenesis of neurodegenerative disorders. Our previous findings suggested cannabinoids and Autacoid Local Injury Antagonism Amides (ALIAmides) attenuate glial response in models of neurodegeneration. The present study was aimed at exploring palmitoylethanolamide (PEA) ability to mitigate ß-amyloid (Aß)-induced astrogliosis. Experiments were carried out to investigate PEA's (10(-7) M) effects upon the expression and release of pro-inflammatory molecules in rat primary astrocytes activated by soluble Aß(1-42) (1 µg/ml) as well as to identify mechanisms responsible for such actions. The effects of Aß and exogenous PEA on the astrocyte levels of the endocannabinoidsand of endogenous ALIAmides were also studied. The peroxisome proliferator-activated receptor (PPAR)-α (MK886, 3 µM) or PPAR-γ (GW9662, 9 nM) antagonists were co-administered with PEA. Aß elevated endogenous PEA and d5-2-arachidonoylglycerol (2-AG) levels. Exogenous PEA blunted the Aß-induced expression of pro-inflammatory molecules. This effect was reduced by PPAR-α antagonist. Moreover, this ALIAmide, like Aß, increased 2-AG levels. These results indicate that PEA exhibits anti-inflammatory properties able to counteract Aß-induced astrogliosis, and suggest novel treatment for neuroinflammatory/ neurodegenerative processes.
Assuntos
Peptídeos beta-Amiloides/efeitos adversos , Anti-Inflamatórios não Esteroides/farmacologia , Astrócitos/efeitos dos fármacos , Gliose/tratamento farmacológico , Inflamação/tratamento farmacológico , Ácidos Palmíticos/farmacologia , Fragmentos de Peptídeos/efeitos adversos , Amidas , Animais , Animais Recém-Nascidos , Astrócitos/citologia , Astrócitos/metabolismo , Western Blotting , Ensaio de Desvio de Mobilidade Eletroforética , Endocanabinoides , Etanolaminas , Imunofluorescência , Gliose/etiologia , Humanos , Inflamação/etiologia , PPAR alfa/antagonistas & inibidores , PPAR alfa/metabolismo , PPAR gama/antagonistas & inibidores , PPAR gama/metabolismo , RNA Mensageiro/genética , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo RealRESUMO
Impulsive action can be defined as the inability to withhold a response and represents one of the dimensions of the broad construct impulsivity. Here, we characterized a modified differential reinforcement of low rates of responding (DRL) task developed in our laboratory, in which impulsive action is measured in ad libitum fed/watered subjects. Specifically, we first determined the effects of both sex and estrous cycle on impulsive action by systematically comparing male and estrous-synchronized female subjects. In addition, we evaluated the convergent validity of this modified DRL task by testing the effects of the D2R/5HT2AR antagonist, aripiprazole, and the noncompetitive NMDAR antagonist, MK-801. Finally, we tested the effects of the selective antagonist BD-1063 and agonist PRE-084 of Sigma-1 receptor (Sig-1R) on impulsive action using this modified DRL task. We found that female rats showed and increased inability to withhold a response when compared to males, and this effect was driven by the metestrus/diestrus phase of the estrous cycle. In addition, aripiprazole and MK-801 fully retained their capability to reduce and increase impulsive action, respectively. Finally, the selective Sig-1R antagonist, BD-1063 dose-dependently reduced the inability to withhold a response in both sexes, though more potently in female rats. In summary, we show that impulsive action, as measured in a modified DRL task which minimizes energy-homeostatic influences, is a function of both sex and estrous cycle. Furthermore, we validate the convergent validity of the task and provide evidence that Sig-1R antagonism may represent a novel pharmacological strategy to reduce impulsive action.
Assuntos
Aripiprazol/farmacologia , Comportamento Animal/efeitos dos fármacos , Maleato de Dizocilpina/farmacologia , Comportamento Impulsivo/efeitos dos fármacos , Piperazinas/farmacologia , Receptores sigma/efeitos dos fármacos , Animais , Comportamento de Escolha/efeitos dos fármacos , Antagonistas dos Receptores de Dopamina D2/farmacologia , Ciclo Estral/efeitos dos fármacos , Feminino , Masculino , Ratos , Ratos Wistar , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Agonistas do Receptor 5-HT2 de Serotonina/farmacologia , Receptor Sigma-1RESUMO
People of recent sub-Saharan African ancestry develop kidney failure much more frequently than other groups. A large fraction of this disparity is due to two coding sequence variants in the APOL1 gene. Inheriting two copies of these APOL1 risk variants, known as G1 and G2, causes high rates of focal segmental glomerulosclerosis (FSGS), HIV-associated nephropathy and hypertension-associated end-stage kidney disease. Disease risk follows a recessive mode of inheritance, which is puzzling given the considerable data that G1 and G2 are toxic gain-of-function variants. We developed coisogenic bacterial artificial chromosome (BAC) transgenic mice harboring either the wild-type (G0), G1 or G2 forms of human APOL1. Expression of interferon gamma (IFN-γ) via plasmid tail vein injection results in upregulation of APOL1 protein levels together with robust induction of heavy proteinuria and glomerulosclerosis in G1/G1 and G2/G2 but not G0/G0 mice. The disease phenotype was greater in G2/G2 mice. Neither heterozygous (G1/G0 or G2/G0) risk variant mice nor hemizygous (G1/-, G2/-) mice had significant kidney injury in response to IFN-γ, although the heterozygous mice had a greater proteinuric response than the hemizygous mice, suggesting that the lack of significant disease in humans heterozygous for G1 or G2 is not due to G0 rescue of G1 or G2 toxicity. Studies using additional mice (multicopy G2 and a non-isogenic G0 mouse) supported the notion that disease is largely a function of the level of risk variant APOL1 expression. Together, these findings shed light on the recessive nature of APOL1-nephropathy and present an important model for future studies.
Assuntos
Nefropatia Associada a AIDS , Apolipoproteína L1 , Animais , Apolipoproteína L1/genética , Apolipoproteína L1/metabolismo , Cromossomos Artificiais Bacterianos/metabolismo , Mutação com Ganho de Função , Predisposição Genética para Doença , Humanos , Camundongos , Camundongos TransgênicosRESUMO
Alcohol use disorder (AUD) is a major cause of morbidity and mortality worldwide, for which new efficacious treatments are necessary. The opioid receptor system is a mediator of the rewarding effects of alcohol; in particular, while activation of µ opioid receptors enhances ethanol intake in rodents, opioid-receptor antagonists, such as naloxone and naltrexone, reduce its pleasurable and reinforcing effects, thereby decreasing alcohol. Sigma receptors (Sig-Rs) have been proposed as modulators of the effects of alcohol and, therefore, as a potential new pharmacological target for AUD. Somewhat analogously to µ opioid ligands, SigR agonists increase, while SigR antagonists decrease alcohol intake in animal models of excessive alcohol drinking. However, a potential cross-talk between these two receptor systems in relation to alcohol consumption has so far not been investigated. Here, we addressed this question pharmacologically, by testing the effects of either activating or inhibiting opioid receptors on the heavy alcohol drinking induced by chronic stimulation of SigR in alcohol-preferring rats. We found that the opioid receptor agonist morphine, which per se increases ethanol intake, at a sub-threshold dose reduces the binge-like drinking induced by the repeated treatment with the SigR agonist 1,3-di-o-tolylguanidine (DTG); conversely, the opioid receptor antagonist naltrexone, which per se reduces ethanol intake, at a sub-threshold dose potentiates the DTG-induced binge-like drinking. Our data show a cross-talk between the opioid and SigR systems relevant to the modulation of alcohol drinking, which provides important insights into the neurobiology of AUD and may lead to the development of novel therapies, either standalone or in combination.
Assuntos
Consumo Excessivo de Bebidas Alcoólicas/tratamento farmacológico , Consumo Excessivo de Bebidas Alcoólicas/etiologia , Depressores do Sistema Nervoso Central/administração & dosagem , Etanol/administração & dosagem , Guanidinas/efeitos adversos , Guanidinas/farmacologia , Morfina/administração & dosagem , Naltrexona/administração & dosagem , Antagonistas de Entorpecentes/administração & dosagem , Receptores sigma/agonistas , Receptores sigma/antagonistas & inibidores , Animais , Relação Dose-Resposta a Droga , Masculino , Morfina/farmacologia , Naltrexona/farmacologia , Antagonistas de Entorpecentes/farmacologia , Ratos , AutoadministraçãoRESUMO
There is increasing interest in developing drugs that act at α4ß2 nicotinic acetylcholine receptors (nAChRs) to treat alcohol use disorder. The smoking cessation agent varenicline, a partial agonist of α4ß2 nAChRs, reduces alcohol intake, but its use can be limited by side effects at high therapeutic doses. There are two stoichiometric forms of α4ß2 nAChRs, (α4)3(ß2)2 and (α4)2(ß2)3. Here we investigated the hypothesis that NS9283, a positive allosteric modulator selective for the (α4)3(ß2)2 form, reduces ethanol consumption. NS9283 increased the potency of varenicline to activate and desensitize (α4)3(ß2)2 nAChRs in vitro without affecting other known targets of varenicline. In male and female C57BL/6J mice, NS9283 (10 mg/kg) reduced ethanol intake in a two-bottle choice, intermittent drinking procedure without affecting saccharin intake, ethanol-induced incoordination or ethanol-induced loss of the righting reflex. Subthreshold doses of NS9283 (2.5 mg/kg) plus varenicline (0.1 mg/kg) synergistically reduced ethanol intake in both sexes. Finally, despite having no aversive valence of its own, NS9283 enhanced ethanol-conditioned place aversion. We conclude that compounds targeting the (α4)3(ß2)2 subtype of nAChRs can reduce alcohol consumption, and when administered in combination with varenicline, may allow use of lower varenicline doses to decrease varenicline side effects.
Assuntos
Consumo de Bebidas Alcoólicas/tratamento farmacológico , Consumo de Bebidas Alcoólicas/metabolismo , Etanol/administração & dosagem , Agonistas Nicotínicos/administração & dosagem , Receptores Nicotínicos/metabolismo , Consumo de Bebidas Alcoólicas/psicologia , Animais , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Oxidiazóis/administração & dosagem , Piridinas/administração & dosagem , Autoadministração , Vareniclina/administração & dosagemRESUMO
Cannabidiol (CBD) is the main non-psychotropic component of the glandular hairs of Cannabis sativa. It displays a plethora of actions including anticonvulsive, sedative, hypnotic, antipsychotic, antiinflammatory and neuroprotective properties. However, it is well established that CBD produces its biological effects without exerting significant intrinsic activity upon cannabinoid receptors. For this reason, CBD lacks the unwanted psychotropic effects characteristic of marijuana derivatives, so representing one of the bioactive constituents of Cannabis sativa with the highest potential for therapeutic use.The present review reports the pharmacological profile of CBD and summarizes results from preclinical and clinical studies utilizing CBD, alone or in combination with other phytocannabinoids, for the treatment of a number of CNS disorders.
Assuntos
Canabidiol/farmacologia , Cannabis/química , Doenças do Sistema Nervoso Central/tratamento farmacológico , Animais , Canabidiol/uso terapêutico , Canabidiol/toxicidade , HumanosRESUMO
BACKGROUND: Despite the high cost and widespread prevalence of alcohol use disorders, treatment options are limited, underscoring the need for new, effective medications. Previous results using protein kinase C epsilon (PKCε) knockout mice, RNA interference against PKCε, and peptide inhibitors of PKCε predict that small-molecule inhibitors of PKCε should reduce alcohol consumption in humans. METHODS: We designed a new class of PKCε inhibitors based on the Rho-associated protein kinase (ROCK) inhibitor Y-27632. In vitro kinase and binding assays were used to identify the most potent compounds. Their effects on ethanol-stimulated synaptic transmission; ethanol, sucrose, and quinine consumption; ethanol-induced loss of righting; and ethanol clearance were studied in mice. RESULTS: We identified two compounds that inhibited PKCε with Ki <20 nM, showed selectivity for PKCε over other kinases, crossed the blood-brain barrier, achieved effective concentrations in mouse brain, prevented ethanol-stimulated gamma-aminobutyric acid release in the central amygdala, and reduced ethanol consumption when administered intraperitoneally at 40 mg/kg in wild-type but not in Prkce-/- mice. One compound also reduced sucrose and saccharin consumption, while the other was selective for ethanol. Both transiently impaired locomotion through an off-target effect that did not interfere with their ability to reduce ethanol intake. One compound prolonged recovery from ethanol-induced loss of righting but this was also due to an off-target effect since it was present in Prkce-/- mice. Neither altered ethanol clearance. CONCLUSIONS: These results identify lead compounds for development of PKCε inhibitors that reduce alcohol consumption.
Assuntos
Consumo de Bebidas Alcoólicas/tratamento farmacológico , Núcleo Central da Amígdala/enzimologia , Proteína Quinase C-épsilon/genética , Inibidores de Proteínas Quinases/farmacologia , Transmissão Sináptica/efeitos dos fármacos , Alcoolismo/enzimologia , Alcoolismo/fisiopatologia , Amidas/farmacocinética , Amidas/farmacologia , Animais , Núcleo Central da Amígdala/efeitos dos fármacos , Núcleo Central da Amígdala/fisiopatologia , Depressores do Sistema Nervoso Central/farmacologia , Condicionamento Psicológico , Modelos Animais de Doenças , Etanol , Injeções Intraperitoneais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Inibidores de Proteínas Quinases/farmacocinética , Piridinas/farmacocinética , Piridinas/farmacologiaRESUMO
RATIONALE: Anxiety disorders are the most common mental disorders in the USA. Characterized by feelings of uncontrollable apprehension, they are accompanied by physical, affective, and behavioral symptoms. The neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) and its receptor PAC1 (PAC1R) are highly expressed in the central nucleus of the amygdala (CeA), and they have gained growing attention for their proposed role in mediating the body's response to stress. OBJECTIVES: The aim of this study was to evaluate the anxiogenic effects of PACAP in the CeA and its effects on the hypothalamic-pituitary-adrenal (HPA) axis. Furthermore, the mechanism of action of PACAP in the CeA was investigated. METHODS: PACAP was microinfused into the CeA of rats, and its effects in the elevated plus maze (EPM), the defensive withdrawal tests, and plasma corticosterone levels were evaluated. The ability of the melanocortin receptor antagonist SHU9119 to block PACAP effect in the EPM was assessed. RESULTS: Intra-CeA PACAP exerted a dose-dependent anxiogenic effect and activated the HPA axis. In contrast, PACAP microinfused into the basolateral nucleus of the amygdala (BlA) had no effect. Finally, the anxiogenic effect of intra-CeA PACAP was prevented by SHU9119. CONCLUSIONS: These data prove an anxiogenic role for the PACAP system of the CeA and reveal that the melanocortin receptor 4 (MC4R) system of CeA mediates these effects. Our data provide insights into this neuropeptide system as a mechanism for modulating the behavioral and endocrine response to stress and suggest that dysregulations of this system may contribute to the pathophysiology of anxiety-related disorders.
Assuntos
Ansiedade , Comportamento Animal/efeitos dos fármacos , Núcleo Central da Amígdala/efeitos dos fármacos , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Neurotransmissores/farmacologia , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/farmacologia , Sistema Hipófise-Suprarrenal/efeitos dos fármacos , Receptor Tipo 4 de Melanocortina/efeitos dos fármacos , Animais , Transtornos de Ansiedade , Complexo Nuclear Basolateral da Amígdala/efeitos dos fármacos , Complexo Nuclear Basolateral da Amígdala/metabolismo , Núcleo Central da Amígdala/metabolismo , Corticosterona/sangue , Emoções/efeitos dos fármacos , Sistema Hipotálamo-Hipofisário/metabolismo , Masculino , Hormônios Estimuladores de Melanócitos/farmacologia , Sistema Hipófise-Suprarrenal/metabolismo , Ratos , Receptor Tipo 4 de Melanocortina/metabolismo , Receptores de Melanocortina/antagonistas & inibidores , Receptores de Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/metabolismoRESUMO
BACKGROUND: Major depressive disorder (MDD) is a chronic, life-threatening psychiatric condition characterized by depressed mood, psychomotor alterations, and a markedly diminished interest or pleasure in most activities known as anhedonia. Available pharmacotherapies have limited success and the need for new strategies is clear. Recent studies attribute a major role to the pituitary adenylate cyclase-activating polypeptide (PACAP) system in mediating the response to stress. PACAP knockout mice display profound alterations in depressive-like behaviors, and genetic association studies have demonstrated that genetic variants of the PACAP gene are associated with MDD. However, the effects of PACAP administration on depressive-like behaviors in rodents have not yet been systematically examined. OBJECTIVES: The present study investigated the effects of central administration of PACAP in rats on depressive-like behaviors, using well-established animal models that represent some of the endophenotypes of depression. METHODS: We used intracranial self-stimulation (ICSS) to assess the brain reward function, saccharin preference test to assess anhedonia, social interaction to assess social withdrawal, and forced swim test (FST) to assess behavioral despair. RESULTS: PACAP raised the current threshold for ICSS, elevation blocked by the PACAP antagonist PACAP(6-38). PACAP reduced the preference for a sweet saccharin solution and reduced the time the rats spent interacting with a novel animal. Interestingly, PACAP administration did not affect immobility in the FST. CONCLUSIONS: Our results demonstrate a role for the central PACAP/PAC1R system in the regulation of depressive-like behaviors and suggest that hyperactivity of the PACAP/PAC1R system may contribute to the pathophysiology of depression, particularly the associated anhedonic symptomatology and social dysfunction.
Assuntos
Depressão/induzido quimicamente , Depressão/metabolismo , Fenótipo , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/administração & dosagem , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/toxicidade , Adenilil Ciclases/metabolismo , Animais , Depressão/psicologia , Relação Dose-Resposta a Droga , Infusões Intraventriculares , Masculino , Ratos , Ratos WistarRESUMO
Sigma-1 receptor (Sig-1R) has been proposed as a novel therapeutic target for drug and alcohol addiction. We have shown previously that Sig-1R agonists facilitate the reinforcing effects of ethanol and induce binge-like drinking, while Sig-1R antagonists on the other hand block excessive drinking in genetic and environmental models of alcoholism, without affecting intake in outbred non-dependent rats. Even though significant progress has been made in understanding the function of Sig-1R in alcohol reinforcement, its role in the early and late stage of alcohol addiction remains unclear. Administration of the selective Sig-1R antagonist BD-1063 dramatically reduced the acquisition of alcohol drinking behavior as well as the preference for alcohol in genetically selected TSRI Sardinian alcohol preferring (Scr:sP) rats; the treatment had instead no effect on total fluid intake, food intake or body weight gain, proving selectivity of action. Furthermore, BD-1063 dose-dependently decreased alcohol-seeking behavior in rats trained under a second-order schedule of reinforcement, in which responding is maintained by contingent presentation of a conditioned reinforcer. Finally, an innate elevation in Sig-1R protein levels was found in the nucleus accumbens of alcohol-preferring Scr:sP rats, compared to outbred Wistar rats, alteration which was normalized by chronic, voluntary alcohol drinking. Taken together these findings demonstrate that Sig-1R blockade reduces the propensity to both acquire alcohol drinking and to seek alcohol, and point to the nucleus accumbens as a potential key region for the effects observed. Our data suggest that Sig-1R antagonists may have therapeutic potential in multiple stages of alcohol addiction.
Assuntos
Consumo de Bebidas Alcoólicas/fisiopatologia , Comportamento de Procura de Droga/fisiologia , Receptores sigma/fisiologia , Consumo de Bebidas Alcoólicas/tratamento farmacológico , Animais , Núcleo Central da Amígdala/metabolismo , Comportamento de Procura de Droga/efeitos dos fármacos , Etanol , Masculino , Núcleo Accumbens/metabolismo , Piperazinas/administração & dosagem , Ratos , Ratos Wistar , Receptores sigma/antagonistas & inibidores , Receptores sigma/metabolismo , Receptor Sigma-1RESUMO
Corticotrophin-releasing factor (CRF) is a 41 amino acid neuropeptide that coordinates adaptive responses to stress. CRF projections from neurons in the central nucleus of the amygdala (CeA) to the brainstem are of particular interest for their role in motivated behavior. To directly examine the anatomy and function of CRF neurons, we generated a BAC transgenic Crh-Cre rat in which bacterial Cre recombinase is expressed from the Crh promoter. Using Cre-dependent reporters, we found that Cre expressing neurons in these rats are immunoreactive for CRF and are clustered in the lateral CeA (CeL) and the oval nucleus of the BNST. We detected major projections from CeA CRF neurons to parabrachial nuclei and the locus coeruleus, dorsal and ventral BNST, and more minor projections to lateral portions of the substantia nigra, ventral tegmental area, and lateral hypothalamus. Optogenetic stimulation of CeA CRF neurons evoked GABA-ergic responses in 11% of non-CRF neurons in the medial CeA (CeM) and 44% of non-CRF neurons in the CeL. Chemogenetic stimulation of CeA CRF neurons induced Fos in a similar proportion of non-CRF CeM neurons but a smaller proportion of non-CRF CeL neurons. The CRF1 receptor antagonist R121919 reduced this Fos induction by two-thirds in these regions. These results indicate that CeL CRF neurons provide both local inhibitory GABA and excitatory CRF signals to other CeA neurons, and demonstrate the value of the Crh-Cre rat as a tool for studying circuit function and physiology of CRF neurons.
RESUMO
Highly palatable foods and dieting are major contributing factors for the development of compulsive eating in obesity and eating disorders. We previously demonstrated that intermittent access to palatable food results in corticotropin-releasing factor-1 (CRF1) receptor antagonist-reversible behaviors, which include excessive palatable food intake, hypophagia of regular chow, and anxiety-like behavior. However, the brain areas mediating these effects are still unknown. Male Wistar rats were either fed chow continuously for 7 days/week (Chow/Chow group), or fed chow intermittently 5 days/week, followed by a sucrose, palatable diet 2 days/week (Chow/Palatable group). Following chronic diet alternation, the effects of microinfusing the CRF1 receptor antagonist R121919 (0, 0.5, 1.5 µg/side) in the central nucleus of the amygdala (CeA), the basolateral nucleus of the amygdala (BlA), or the bed nucleus of the stria terminalis (BNST) were evaluated on excessive intake of the palatable diet, chow hypophagia, and anxiety-like behavior. Furthermore, CRF immunostaining was evaluated in the brain of diet cycled rats. Intra-CeA R121919 blocked both excessive palatable food intake and anxiety-like behavior in Chow/Palatable rats, without affecting chow hypophagia. Conversely, intra-BlA R121919 reduced the chow hypophagia in Chow/Palatable rats, without affecting excessive palatable food intake or anxiety-like behavior. Intra-BNST treatment had no effect. The treatments did not modify the behavior of Chow/Chow rats. Immunohistochemistry revealed an increased number of CRF-positive cells in CeA--but not in BlA or BNST--of Chow/Palatable rats, during both withdrawal and renewed access to the palatable diet, compared with controls. These results provide functional evidence that the CRF-CRF1 receptor system in CeA and BlA has a differential role in mediating maladaptive behaviors resulting from palatable diet cycling.