RESUMEN
Alcohol relapse is the treatment target for medications development for alcohol dependence. Aticaprant, a selective and short-acting kappa-opioid receptor (KOR) antagonist, has recently been under development for new clinical implications (depression or anhedonia). Recent studies have also found that aticaprant reduces alcohol intake and prevents stress- triggered alcohol seeking in rodents via a KOR-mediated mechanism. Here, we further investigated whether aticaprant alone or in combination with naltrexone (mu-opioid receptor [MOR] antagonist) altered alcohol relapse-like drinking using a mouse alcohol deprivation effect (ADE) paradigm to mimic the relapse episodes in human alcoholics. A long-acting and selective KOR antagonist nor-BNI was used as a reference compound for the effects of the KOR antagonism on the ADE. After 3-week intermittent-access alcohol drinking (two-bottle choice, 24-h access every other day), male and female mice displayed excessive alcohol intake and then pronounced ADE after 1-week abstinence. Aticaprant alone decreased alcohol ADE in a dose- dependent manner (1-3 mg/kg) in both males and females. Aticaprant at a lower dose (0.3 mg/kg) than the effective one (3 mg/kg) combined with a low dose of naltrexone (1 mg/kg) reduced the ADE in both sexes, and the combination was effective after a multi-dosing regimen (5 daily injections during the abstinence) without development of tolerance, suggesting synergistic effects of the combination. In contrast, nor-BNI alone or with naltrexone had no effect on the ADE in either sex. Our present study suggests that a combination of clinically developed, short-acting KOR antagonist aticaprant with low-dose naltrexone has therapeutic potential in alcohol "relapse" treatment.
RESUMEN
Opioid use disorders (OUDs) are diseases of the brain with behavioral, psychological, neurobiological, and medical manifestations. Vulnerability to OUDs can be affected by factors such as genetic background, environment, stress, and prolonged exposure to µ-opioid agonists for analgesia. Two standard-of-care maintenance medications, methadone and buprenorphine-naloxone, have a long-term positive influence on health of persons with opioid addiction. Buprenorphine and another medication, naltrexone, have also been approved for administration as monthly depot injections. However, neither medication is used as widely as needed, due largely to stigma, insufficient medical education or training, inadequate resources, and inadequate access to treatment. Ongoing directions in the field include (i) personalized approaches leveraging genetic factors for prediction of OUD vulnerability and prognosis, or for targeted pharmacotherapy, and (ii) development of novel analgesic medicines with new neurobiological targets with reduced abuse potential, reduced toxicity, and improved effectiveness, especially for chronic pain states other than cancer pain.
Asunto(s)
Investigación Biomédica , Trastornos Relacionados con Opioides/terapia , Analgésicos Opioides/química , Encéfalo/metabolismo , Humanos , Trastornos Relacionados con Opioides/epidemiología , Salud Pública , Receptores Opioides mu/metabolismoRESUMEN
Opioid receptor antagonist naltrexone reduces alcohol consumption and relapse in both humans and rodents. This study investigated whether hypothalamic proopiomelanocortin (POMC) neurons (producing beta-endorphin and melanocortins) play a role in alcohol drinking behaviors. Both male and female mice with targeted deletion of two neuronal Pomc enhancers nPE1 and nPE2 (nPE-/-), resulting in hypothalamic-specific POMC deficiency, were studied in short-access (4-h/day) drinking-in-the-dark (DID, alcohol in one bottle, intermittent access (IA, 24-h cycles of alcohol access every other day, alcohol vs. water in a two-bottle choice) and alcohol deprivation effect (ADE) models. Wild-type nPE+/+ exposed to 1-week DID rapidly established stable alcohol drinking behavior with more intake in females, whereas nPE-/- mice of both sexes had less intake and less preference. Although nPE-/- showed less saccharin intake and preference than nPE+/+, there was no genotype difference in sucrose intake or preference in the DID paradigm. After 3-week IA, nPE+/+ gradually escalated to high alcohol intake and preference, with more intake in females, whereas nPE-/- showed less escalation. Pharmacological blockade of mu-opioid receptors with naltrexone reduced intake in nPE+/+ in a dose-dependent manner, but had blunted effects in nPE-/- of both sexes. When alcohol was presented again after 1-week abstinence from IA, nPE+/+ of both sexes displayed significant increases in alcohol intake (ADE or relapse-like drinking), with more pronounced ADE in females, whereas nPE-/- did not show ADE in either sex. Our results suggest that neuronal POMC is involved in modulation of alcohol 'binge' drinking, escalation and 'relapse', probably via hypothalamic-mediated mechanisms, with sex differences.
Asunto(s)
Insuficiencia Suprarrenal/metabolismo , Consumo de Bebidas Alcohólicas/metabolismo , Obesidad/metabolismo , Proopiomelanocortina/deficiencia , Insuficiencia Suprarrenal/genética , Consumo de Bebidas Alcohólicas/tratamiento farmacológico , Consumo de Bebidas Alcohólicas/genética , Animales , Etanol/farmacología , Femenino , Genotipo , Hipotálamo/efectos de los fármacos , Hipotálamo/metabolismo , Masculino , Ratones , Ratones Noqueados , Naltrexona/farmacología , Obesidad/genética , Proopiomelanocortina/genética , Proopiomelanocortina/metabolismoRESUMEN
Recent research suggests an involvement of pro-opiomelanocortin (POMC) gene products (e.g., beta-endorphin) in modulating cocaine-induced reward and addiction-like behaviors in rodents. In this study, we investigated whether chronic "binge" cocaine and its withdrawal altered POMC gene expression in the brain of rats. Male Fischer rats were treated with two different chronic (14-day) "binge" pattern cocaine administration regimens (three injections at 1-h intervals, i.p.): steady-dose (45mg/kg/day) and escalating-dose (90mg/kg on the last day). Although there was no POMC mRNA alteration after chronic steady-dose cocaine, a significant decrease in POMC mRNA levels in the hypothalamus was found after chronic escalating-dose cocaine. In contrast, after acute (1-day) withdrawal from chronic "binge" escalating-dose regimen, but not steady-dose regimen, there were increased hypothalamic POMC mRNA levels that persisted into 14days of protracted withdrawal. To study the role of the endogenous opioid systems in the cocaine withdrawal effects, we administered a single naloxone injection (1mg/kg) that caused elevated POMC mRNA levels observed 24h later in cocaine naïve rats, but it did not lead to further increases in cocaine-withdrawn rats. Our results suggest that during withdrawal from chronic "binge" escalating-dose cocaine: (1) there was a persistent increase in hypothalamic POMC gene expression; and (2) hyposensitivity of the POMC gene expression to naloxone indicates altered opioidergic tone at or above the hypothalamic level.
Asunto(s)
Trastornos Relacionados con Cocaína/metabolismo , Cocaína/administración & dosificación , Inhibidores de Captación de Dopamina/administración & dosificación , Hipotálamo/metabolismo , Proopiomelanocortina/metabolismo , Síndrome de Abstinencia a Sustancias/metabolismo , Amígdala del Cerebelo/efectos de los fármacos , Amígdala del Cerebelo/metabolismo , Animales , Peso Corporal/efectos de los fármacos , Corticosterona/sangre , Hipotálamo/efectos de los fármacos , Masculino , Naloxona/farmacología , Antagonistas de Narcóticos/farmacología , ARN Mensajero/metabolismo , Ratas Endogámicas F344 , Esquema de RefuerzoRESUMEN
Abuse and addiction to prescription opioids such as oxycodone (a short-acting Mu opioid receptor (MOP-r) agonist) in adolescence is a pressing public health issue. We have previously shown differences in oxycodone self-administration behaviors between adolescent and adult C57BL/6J mice and expression of striatal neurotransmitter receptor genes, in areas involved in reward. In this study, we aimed to determine whether oxycodone self-administration differentially affects genes regulating synaptic plasticity in the hippocampus of adolescent compared to adult mice, since the hippocampus may be involved in learning aspects associated with chronic drug self administration. Hippocampus was isolated for mRNA analysis from mice that had self administered oxycodone (0.25 mg/kg/infusion) 2h/day for 14 consecutive days or from yoked saline controls. Gene expression was analyzed with real-time polymerase chain reaction (PCR) using a commercially available "synaptic plasticity" PCR array containing 84 genes. We found that adolescent and adult control mice significantly differed in the expression of several genes in the absence of oxycodone exposure, including those coding for mitogen-activated protein kinase, calcium/calmodulin-dependent protein kinase II gamma subunit, glutamate receptor, ionotropic AMPA2 and metabotropic 5. Chronic oxycodone self administration increased proviral integration site 1 (Pim1) and thymoma viral proto-oncogene 1 mRNA levels compared to controls in both age groups. Both Pim1 and cadherin 2 mRNAs showed a significant combined effect of Drug Condition and Age × Drug Condition. Furthermore, the mRNA levels of both cadherin 2 and cAMP response element modulators showed an experiment-wise significant difference between oxycodone and saline control in adult but not in adolescent mice. Overall, this study demonstrates for the first time that chronic oxycodone self-administration differentially alters synaptic plasticity gene expression in the hippocampus of adolescent and adult mice.
Asunto(s)
Hipocampo/efectos de los fármacos , Hipocampo/crecimiento & desarrollo , Narcóticos/administración & dosificación , Trastornos Relacionados con Opioides/metabolismo , Oxicodona/administración & dosificación , Envejecimiento/efectos de los fármacos , Envejecimiento/metabolismo , Animales , Cadherinas/metabolismo , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/metabolismo , Modulador del Elemento de Respuesta al AMP Cíclico/metabolismo , Expresión Génica , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Hipocampo/metabolismo , Masculino , Ratones Endogámicos C57BL , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteínas Proto-Oncogénicas c-pim-1/metabolismo , ARN Mensajero/metabolismo , Receptor del Glutamato Metabotropico 5/metabolismo , Receptores AMPA/metabolismo , AutoadministraciónRESUMEN
BACKGROUND: Stress is a critical risk factor affecting both the development of and the relapse to drug addictions. Drug addictions are caused by genetic, environmental and drug-induced factors. The objective of this hypothesis-driven association study was to determine if genetic variants in stress-related genes are associated with heroin addiction. METHODS: 112 selected genetic variants in 26 stress-related genes were genotyped in 852 case subjects and 238 controls of predominantly European ancestry. The case subjects are former heroin addicts with a history of at least one year of daily multiple uses of heroin, treated at a methadone maintenance treatment program (MMTP). The two most promising SNPs were subsequently tested in an African-American sample comprising of 314 cases and 208 control individuals. RESULTS: Nineteen single nucleotide polymorphisms (SNPs) in 9 genes (AVP, AVPR1A, CRHR1, CRHR2, FKBP5, GAL, GLRA1, NPY1R and NR3C2) showed nominally significant association with heroin addiction. The associations of two FKBP5 SNPs that are part of one haplotype block, rs1360780 (intron 2) and rs3800373 (the 3' untranslated region), remained significant after correction for multiple testing (Pcorrected=0.03; OR=2.35, Pcorrected=0.0018; OR=2.85, respectively). The two SNPs also showed nominally significant association (P<0.05) with heroin addiction in an independent African-American cohort. FKBP5 is a co-chaperone that regulates glucocorticoid sensitivity. These FKBP5 SNPs were previously associated with diverse affective disorders and showed functional differences in gene expression and stress response. This study also supports our and others' previous reports of association of the GAL SNP rs694066 and the AVPR1A SNPs rs11174811, rs1587097 and rs10784339 with heroin and general drug addiction, respectively. CONCLUSIONS: This study suggests that variations in the FKBP5 gene contribute to the development of opiate addiction by modulating the stress response. These findings may enhance the understanding of the interaction between stress and heroin addiction.
Asunto(s)
Dependencia de Heroína/genética , Estrés Psicológico/genética , Proteínas de Unión a Tacrolimus/fisiología , Adulto , Estudios de Casos y Controles , Femenino , Frecuencia de los Genes , Predisposición Genética a la Enfermedad , Genotipo , Haplotipos , Dependencia de Heroína/epidemiología , Humanos , Desequilibrio de Ligamiento , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Estrés Psicológico/epidemiología , Proteínas de Unión a Tacrolimus/genéticaRESUMEN
Illicit use of prescription opioid analgesics (e.g., oxycodone) in adolescence is a pressing public health issue. Our goal was to determine whether oxycodone self administration differentially affects striatal neurotransmitter receptor gene expression in the dorsal striatum of adolescent compared to adult C57BL/6J mice. Groups of adolescent mice (4 weeks old, n=12) and of adult mice (11 weeks old, n=11) underwent surgery during which a catheter was implanted into their jugular veins. After recovering from surgery, mice self administered oxycodone (0.25 mg/kg/infusion) 2 h/day for 14 consecutive days or served as yoked saline controls. Mice were sacrificed within 1h after the last self-administration session and the dorsal striatum was isolated for mRNA analysis. Gene expression was analyzed with real time PCR using a commercially available neurotransmitter receptor PCR array containing 84 genes. We found that adolescent mice self administered less oxycodone than adult mice over the 14 days. Monoamine oxidase A (Maoa) and neuropeptide Y receptor 5 mRNA levels were lower in adolescent mice than in adult mice without oxycodone exposure. Oxycodone self administration increased Maoa mRNA levels compared to controls in both age groups. There was a positive correlation of the amount of oxycodone self administered in the last session or across 14 sessions with Maoa mRNA levels. Gastrin-releasing peptide receptor mRNA showed a significant Drug × Age interaction, with point-wise significance. More genes in the dorsal striatum of adolescents (19) changed in response to oxycodone self administration compared to controls than in adult (4) mice. Overall, this study demonstrates that repeated oxycodone self administration alters neurotransmitter receptors gene expression in the dorsal striatum of adolescent and adult mice.
Asunto(s)
Cuerpo Estriado/efectos de los fármacos , Cuerpo Estriado/metabolismo , Narcóticos/farmacología , Oxicodona/farmacología , Receptores de Neurotransmisores/metabolismo , Factores de Edad , Animales , Cuerpo Estriado/crecimiento & desarrollo , Comportamiento de Búsqueda de Drogas/fisiología , Expresión Génica/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Monoaminooxidasa/metabolismo , Narcóticos/administración & dosificación , Trastornos Relacionados con Opioides/metabolismo , Oxicodona/administración & dosificación , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Receptores de Neuropéptido Y/metabolismo , AutoadministraciónRESUMEN
Cocaine addiction is driven by genetic, neurologic and environmental components. The D1-like (D1 and D5) and D2-like (D2, D3 and D4) families of dopamine receptors play an important role in modulating the effects of cocaine administration on drug-seeking behavior. The advent of bacterial artificial chromosome-eGFP (enhanced green fluorescent protein) transgenic mice that express eGFP driven by the endogenous D1-receptor (D1-r) or D2-receptor (D2-r) promoters provides a unique opportunity to distinguish between these subpopulations of cells. In an effort to identify cocaine-induced alterations in D1-r- versus D2-r-expressing cells during the initial stages of addiction, we examined cells that expressed D1-rs in Drd1-eGFP mice, or D2-rs in Drd2-eGFP mice, after an acute, 1-day binge pattern of cocaine administration. We used multiphoton confocal microscopy and Visiopharm© software, to conduct unbiased stereological counts of D1-r-labeled or D2-r-labeled cells in various striatal regions. Mice were sacrificed at 30 min and 24-h post cocaine or saline administration. Compared to saline controls, Drd1-eGFP mice that received cocaine had a higher count of D1-r-labeled cells in the dorsolateral (DL) striatum, at the 30-min and 24-h time-points. No changes in the nucleus accumbens (NAc) core or shell were observed in Drd1-eGFP mice. Drd2-eGFP mice that received cocaine had fewer D2-r-labeled cells in the DL striatum and NAc core compared to saline controls. This effect was observed at the 30-min time-point but not at 24h. Drd2-eGFP mice that received cocaine also had fewer numbers of D2-r-labeled cells in the NAc core compared to saline controls, but no significant differences in the number of D2-r-labeled cells in the NAc shell. These results suggest that acute binge pattern cocaine administration may induce region-specific alterations in D1-r or D2-receptor gene expression, and may help elucidate the differential role of dopamine receptors in the initial stages of the addiction cycle.
Asunto(s)
Trastornos Relacionados con Cocaína/metabolismo , Trastornos Relacionados con Cocaína/patología , Cocaína/administración & dosificación , Inhibidores de Captación de Dopamina/administración & dosificación , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D2/metabolismo , Análisis de Varianza , Animales , Recuento de Células , Cocaína/farmacología , Cuerpo Estriado/efectos de los fármacos , Cuerpo Estriado/metabolismo , Cuerpo Estriado/patología , Inhibidores de Captación de Dopamina/farmacología , Proteínas Fluorescentes Verdes/genética , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Microscopía Confocal , Núcleo Accumbens/citología , Núcleo Accumbens/efectos de los fármacos , Núcleo Accumbens/metabolismo , Receptores de Dopamina D1/genética , Receptores de Dopamina D2/genética , Factores de TiempoRESUMEN
C57BL/6J and 129 substrains of mice are known to differ in their basal levels of anxiety and behavioral response to drugs of abuse. We have previously shown strain differences in heroin-induced conditioned place preference (CPP) between C57BL/6J (C57) and 129P3/J (129) mice, and in the regional expression of several receptor and peptide mRNAs. In this study, we examined the contribution of the GABAergic system in the cortex, nucleus accumbens (NAc), caudate putamen (CPu) and the region containing the substantia nigra and ventral tegmental area (SN/VTA) to heroin reward by measuring mRNA levels of 7 of the most commonly expressed GABA-A receptor subunits, and both GABA-B receptor subunits, in these same mice following saline (control) or heroin administration in a CPP design. Using real-time PCR, we studied the effects of strain and heroin administration on GABA-A α1, α2, α3, ß2, and γ2 subunits, which typically constitute synaptic GABA-A receptors, GABA-A α4 and δ subunits, which typically constitute extrasynaptic GABA-A receptors, and GABA-B R1 and R2 subunits. In saline-treated animals, we found an experiment-wise significant strain difference in GABA-Aα2 mRNA expression in the SN/VTA. Point-wise significant strain differences were also observed in GABA-Aα2, GABA-Aα3, and GABA-Aα4 mRNA expression in the NAc, as well as GABA-BR2 mRNA expression in the NAc and CPu, and GABA-BR1 mRNA expression in the cortex. For all differences, 129 mice had higher mRNA expression compared to C57 animals, with the exception of GABA-BR1 mRNA in the cortex where we observed lower levels in 129 mice. Therefore, it may be possible that known behavioral differences between these two strains are, in part, due to differences in their GABAergic systems. While we did not find heroin dose-related changes in mRNA expression levels in C57 mice, we did observe dose-related differences in 129 mice. These results may relate to our earlier behavioral finding that 129 mice are hyporesponsive to the rewarding effects of heroin.
Asunto(s)
Química Encefálica/efectos de los fármacos , Química Encefálica/fisiología , Heroína/farmacología , Narcóticos/farmacología , ARN Mensajero/biosíntesis , Receptores de GABA/biosíntesis , Animales , Condicionamiento Operante/efectos de los fármacos , ADN Complementario/biosíntesis , ADN Complementario/genética , Interpretación Estadística de Datos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos , Reacción en Cadena en Tiempo Real de la Polimerasa , Receptores de GABA-A/metabolismo , Receptores de GABA-B/biosíntesis , Receptores de GABA-B/genética , Especificidad de la EspecieRESUMEN
Addictions are chronic relapsing brain diseases, with behavioral manifestations. Three main factors contribute to the development of an addiction: environment, including stress, the reinforcing effects of the drug, and genetics. In this review we will discuss the involvement of the dysregulation of the stress responsive hypothalamic-pituitary-adrenal (HPA) axis in the acquisition of, and persistence to drug addiction (Section B). Addictions to specific drugs such as cocaine/psychostimulants, alcohol, and mu-opioid receptor agonists (e.g., heroin) have some common direct or downstream effects, including modulation of dopaminergic systems. Through its action on the dopaminergic signaling pathways, cocaine affects the HPA axis, and brain nuclei responsible for movements, and rewarding effects. Several neurobiological systems have been implicated with cocaine addiction, including dopamine, serotonin and glutamate systems, opioid receptor and opioid neuropeptide gene systems, stress-responsive systems including CRF, vasopressin and orexin. The use of animal models (Sections C and D) has been essential for studying the individual vulnerabilities to the effects of drugs of abuse and the neural pathways and neurotransmitters affected by these drugs. Basic clinical research has revealed important relationship between cocaine use, HPA axis responsiveness, and gender (Section E). Finally, we will discuss gene polymorphisms that are associated with drug use (Section F). Results from animal models and basic clinical research have shown important interactions between the dopaminergic and the opioid systems. Hence, compounds modulating the opioid system may be beneficial in treating cocaine addiction.
Asunto(s)
Trastornos Relacionados con Cocaína/tratamiento farmacológico , Estrés Fisiológico/fisiología , Trastornos Relacionados con Sustancias/tratamiento farmacológico , Animales , Conducta Adictiva/fisiopatología , Trastornos Relacionados con Cocaína/fisiopatología , Modelos Animales de Enfermedad , Dopamina/metabolismo , Humanos , Sistema Hipotálamo-Hipofisario/efectos de los fármacos , Sistema Hipotálamo-Hipofisario/metabolismo , Sistema Hipófiso-Suprarrenal/efectos de los fármacos , Sistema Hipófiso-Suprarrenal/metabolismo , Recompensa , Factores Sexuales , Transducción de Señal/efectos de los fármacos , Trastornos Relacionados con Sustancias/fisiopatologíaRESUMEN
In heroin-dependent individuals, the drive to avoid or ameliorate the negative affective/emotional state associated with the discontinuation of heroin contributes to the chronic relapsing nature of the disease. Here, we investigate changes in proopiomelanocortin (POMC) expression at three time points across an extended period of heroin withdrawal in a clinically relevant rodent model of addiction using conditioned place aversion (CPA) in POMC-EGFP (POMC-enhanced green fluorescent protein) bacterial artificial chromosome (BAC) transgenic mice. Neurons expressing POMC-EGFP were found in the medial nucleus of the amygdala (MeA), basomedial amygdala (BMA) and dentate gyrus of hippocampus (DG), as well as the arcuate nucleus of hypothalamus (ARC). Heroin-treated mice displayed robust CPA after acute spontaneous withdrawal (12h), which persisted across the extended (14days) withdrawal period. After 12-h withdrawal, heroin-treated mice showed lower signal intensity of POMC-EGFP-positive cells in the ARC, higher levels of POMC mRNA in the amygdala but lower levels in the hippocampus than saline controls. After 7-d withdrawal, heroin-treated mice showed fewer POMC-EGFP-positive cells in the MeA and lower POMC mRNA in the amygdala than saline controls. After extended (14days) withdrawal, heroin-treated mice showed more POMC-EGFP-positive cells in BMA and DG, increased intensity of POMC-EGFP signal in DG, and higher POMC mRNA levels in the hippocampus compared to controls. Our results show dynamic changes in POMC in hypothalamic and extra-hypothalamic regions that may contribute to the negative affective/emotional state of heroin withdrawal shown by CPA from acute to extended periods of heroin withdrawal.
Asunto(s)
Encéfalo/metabolismo , Dependencia de Heroína/metabolismo , Proopiomelanocortina/biosíntesis , Síndrome de Abstinencia a Sustancias/metabolismo , Animales , Condicionamiento Operante , Modelos Animales de Enfermedad , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Ratones , Ratones Transgénicos , Regiones Promotoras GenéticasRESUMEN
Recent research suggests an involvement of pro-opiomelanocortin (POMC) gene products in modulating cocaine reward and addiction-like behaviors in rodents. In this study, we investigated whether cocaine-induced conditioned place preference (CPP) alters POMC gene expression in the brain or pituitary of rats. Sprague-Dawley rats were conditioned with 4 injections of 0, 10 or 30 mg/kg cocaine (i.p.) over 8 days and tested 4 days after the last conditioning session. Another group received the same pattern of cocaine injections without conditioning. POMC mRNA levels in the hypothalamus (including arcuate nucleus), amygdala and anterior pituitary, as well as plasma ACTH and corticosterone levels were measured. Cocaine place conditioning at 10 and 30 mg/kg doses increased POMC mRNA levels in a dose-dependent manner in the hypothalamus, with no effect in the amygdala. Cocaine CPP had no effect on POMC mRNA levels in the anterior pituitary or on plasma ACTH or corticosterone levels. In rats that received cocaine at 30 mg/kg without conditioning, there was no such effect on hypothalamic POMC mRNA levels. Alteration of POMC gene expression in the hypothalamus is region-specific after cocaine place conditioning, and dose-dependent. The increased POMC gene expression in the hypothalamus suggests that it is involved in the reward/learning process of cocaine-induced conditioning.
Asunto(s)
Trastornos Relacionados con Cocaína/fisiopatología , Cocaína/farmacología , Condicionamiento Psicológico/efectos de los fármacos , Hipotálamo/efectos de los fármacos , Hipotálamo/fisiología , Proopiomelanocortina/genética , Amígdala del Cerebelo/efectos de los fármacos , Amígdala del Cerebelo/fisiología , Animales , Condicionamiento Psicológico/fisiología , Inhibidores de Captación de Dopamina/farmacología , Relación Dosis-Respuesta a Droga , Expresión Génica/efectos de los fármacos , Expresión Génica/fisiología , Masculino , Hipófisis/efectos de los fármacos , Hipófisis/fisiología , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , RecompensaRESUMEN
Antagonism of the kappa opioid receptor (KOR) has been reported to have anti-depressant-like properties. The dynorphin/KOR system is a crucial neurochemical substrate underlying the pathologies of addictive diseases, affective disorders and other disease states. However, the molecular underpinnings and neuroanatomical localization of the dysregulation of this system have not yet been fully elucidated. Utilizing the Porsolt Forced Swim Test (FST), an acute stressor commonly used as in rodent models measuring antidepressant efficacy, male Sprague-Dawley rats were subject to forced swimming for 15 min, treated 1h with vehicle or norbinaltorphimine (nor-BNI) (5 or 10mg/kg), and then 1 day later subject to FST for 5 min. In accordance with previous findings, nor-BNI dose dependently increased climbing time and reduced immobility. In comparison to control animals not exposed to FST, we observed a significant elevation in prodynorphin (pDyn) mRNA levels following FST using real-time optical polymerase chain reaction (PCR) in the caudate putamen but not in the nucleus accumbens, hypothalamus, amygdala, frontal cortex, or hippocampus. nor-BNI treatment did not affect pDyn mRNA levels in comparison to animals that received vehicle. The corresponding brain regions from the opposite hemisphere were analyzed for underlying chromatin modifications of the prodynorphin gene promoter region using chromatin immunoprecipitation with antibodies against specifically methylated histones H3K27Me2, H3K27Me3, H3K4Me2, and H3K4Me3, as well as CREB-1 and MeCP2. Significant alterations in proteins bound to DNA in the Cre-3, Cre-4, and Sp1 regions of the prodynorphin promoter were found in the caudate putamen of the FST saline-treated animals compared to control animals, with no changes observed in the hippocampus. Epigenetic changes resulting in elevated dynorphin levels specifically in the caudate putamen may in part underlie the enduring effects of stress.
Asunto(s)
Núcleo Caudado/metabolismo , Cromatina/genética , Encefalinas/genética , Precursores de Proteínas/genética , Estrés Psicológico/genética , Transcripción Genética , Animales , Inmunoprecipitación de Cromatina , Encefalinas/biosíntesis , Regulación de la Expresión Génica , Masculino , Precursores de Proteínas/biosíntesis , Ratas , Ratas Sprague-Dawley , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
Despite a high prevalence of hepatitis C virus (HCV) among drug users, HCV evaluation and treatment acceptance are extremely low among these patients when referred from drug treatment facilities for HCV management. We sought to increase HCV treatment effectiveness among patients from a methadone maintenance treatment program (MMTP) by maintaining continuity of care. We developed, instituted and retrospectively assessed the effectiveness of an integrated, co-localized care model in which an internist-addiction medicine specialist from MMTP was embedded in the hepatitis clinic. Methadone maintenance treatment program patients were referred, evaluated by the internist and hepatologist in hepatitis clinic and provided HCV treatment with integration between both sites. Of 401 evaluated patients, anti-HCV antibody was detected in 257, 86% of whom were older than 40 years. Hepatitis C virus RNA levels were measured in 222 patients, 65 of whom were aviremic. Of 157 patients with detectable HCV RNA, 125 were eligible for referral to the hepatitis clinic, 76 (61%) of whom accepted and adhered with the referral. Men engaged in MMTP <36 months were significantly less likely to be seen in hepatitis clinic than men in MMTP more than 36 months (odds ratio = 7.7; 95% confidence interval 2.6-22.9) or women. We evaluated liver histology in 63 patients, and 83% had moderate to advanced liver disease. Twenty-four patients initiated treatment with 19 completing and 13 (54%) achieving sustained response. In conclusion, integrated care between the MMTP and the hepatitis clinic improves adherence with HCV evaluation and treatment compared to standard referral practices.
Asunto(s)
Hepatitis C/tratamiento farmacológico , Hepatitis C/epidemiología , Interferón-alfa/uso terapéutico , Metadona/administración & dosificación , Polietilenglicoles/uso terapéutico , Trastornos Relacionados con Sustancias/complicaciones , Adulto , Antivirales/uso terapéutico , Conducta Adictiva , Manejo de la Enfermedad , Femenino , Genotipo , Hepacivirus/efectos de los fármacos , Hepacivirus/genética , Hepacivirus/patogenicidad , Hepatitis C/complicaciones , Humanos , Hígado/patología , Hígado/virología , Cirrosis Hepática/tratamiento farmacológico , Cirrosis Hepática/patología , Cirrosis Hepática/virología , Masculino , Metadona/uso terapéutico , Persona de Mediana Edad , Tratamiento de Sustitución de Opiáceos , ARN Viral/sangre , Proteínas Recombinantes/uso terapéutico , Resultado del TratamientoRESUMEN
Opioid addiction is a chronic disease with high genetic contribution and a large inter-individual variability in therapeutic response. The goal of this study was to identify pharmacodynamic factors that modulate methadone dose requirement. The neurotrophin family is involved in neural plasticity, learning, memory and behavior and deregulated neural plasticity may underlie the pathophysiology of drug addiction. Brain-derived neurotrophic factor (BDNF) was shown to affect the response to methadone maintenance treatment. This study explores the effects of polymorphisms in the nerve growth factor (ß polypeptide) gene, NGFB, on the methadone doses required for successful maintenance treatment for heroin addiction. Genotypes of 14 NGFB polymorphisms were analyzed for association with the stabilizing methadone dose in 72 former severe heroin addicts with no major co-medications. There was significant difference in methadone doses required by subjects with different genotypes of the NGFB intronic single-nucleotide polymorphism rs2239622 (P=0.0002). These results may have clinical importance.
Asunto(s)
Dependencia de Heroína/tratamiento farmacológico , Metadona/uso terapéutico , Factor de Crecimiento Nervioso/genética , Adolescente , Adulto , Anciano , Femenino , Humanos , Masculino , Metadona/administración & dosificación , Persona de Mediana Edad , Polimorfismo de Nucleótido SimpleRESUMEN
We have previously shown strain and dose differences in heroin-induced behavior, reward and regional expression of somatostatin receptor mRNAs in C57BL/6J and 129P3/J mice. Using Real Time PCR we examined the effects of five doses of heroin on the levels of the transcripts of endogenous opioid peptides and their receptors and dopaminergic receptors in the mesocorticolimbic and nigrostriatal pathways in these same mice. Compared to C57BL/6J animals, 129P3/J mice had higher mRNA levels of Oprk1 in the nucleus accumbens and of Oprd1 in the nucleus accumbens and a region containing both the substantia nigra and ventral tegmental area (SN/VTA). In the cortex of 129P3/J mice, lower levels of both Oprk1 and Oprd1 mRNAs were observed. Pdyn mRNA was also lower in the caudate putamen of 129P3/J mice. Strain differences were not found in the levels of Oprm1, Penk or Pomc mRNAs in any region examined. Within strains, complex patterns of heroin dose-dependent changes in the levels of Oprm1, Oprk1 and Oprd1 mRNAs were observed in the SN/VTA. Additionally, Oprd1 mRNA was dose-dependently elevated in the hypothalamus. Also in the hypothalamus, we found higher levels of Drd1a mRNA in C57BL/6J mice than in 129P3/J animals and higher levels of DAT (Slc6a3) mRNA in the caudate putamen of C57BL/6J animals than in 129P3/J counterparts. Heroin had dose-related effects on Drd1a mRNA in the hypothalamus and on Drd2 mRNA in the caudate putamen.
Asunto(s)
Química Encefálica/genética , Regulación de la Expresión Génica , Heroína/farmacología , ARN Mensajero/biosíntesis , Animales , Química Encefálica/efectos de los fármacos , Masculino , Ratones , Ratones de la Cepa 129 , Ratones Endogámicos C57BL , ARN Mensajero/genética , Receptores Opioides delta/agonistas , Receptores Opioides delta/genética , Receptores Opioides kappa/agonistas , Receptores Opioides kappa/genética , Receptores Opioides mu/agonistas , Receptores Opioides mu/genética , Especificidad de la EspecieRESUMEN
Cocaine-induced plasticity of mesocorticolimbic dopamine (DA) neurons, originating in the ventral tegmental area (VTA), persists in the absence of cocaine and may contribute to both drug-craving and relapse. Glutamate AMPA receptors (AMPARs) in these neurons are implicated in this plasticity. However, there is no ultrastructural evidence that the absence of cocaine following repeated administrations affects the critical surface/synaptic availability of AMPAR GluR1 subunits in either DA or non-DA, putative GABAergic neurons within the VTA. To assess this, we used electron microscopic immunolabeling in the VTA of adult male mice sacrificed at 30 min or 72 h after receiving the final of six (15 mg/kg) cocaine injections, a dosing paradigm that resulted in development of locomotor sensitization. At each time point, both cocaine- and saline-injected mice showed AMPAR GluR1 immunogold labeling in somatodendritic profiles, many of which contained immunoperoxidase labeling for the DA-synthesizing enzyme, tyrosine hydroxylase (TH). At 30 min after the last injection, when cocaine was systemically present, only the non-TH labeled dendrites showed a significant increase in the synaptic/plasmalemmal density of GluR1 immunogold particles. At 72 h, when systemic cocaine was depleted, synaptic GluR1 labeling was greatly enhanced in TH-containing dendrites throughout the VTA and in non-TH dendrites of the limbic-associated paranigral VTA. Our results demonstrate that systemic cocaine produces GluR1 trafficking specifically in non-DA neurons of the VTA, which may subsequently contribute to the abstinent-induced enhancement of AMPA receptor synaptic transmission in mesocorticolimbic DA neurons leading to heightened drug seeking behavior.
Asunto(s)
Trastornos Relacionados con Cocaína/fisiopatología , Cocaína/efectos adversos , Neuronas GABAérgicas/efectos de los fármacos , Proteínas del Tejido Nervioso/metabolismo , Plasticidad Neuronal/efectos de los fármacos , Receptores AMPA/metabolismo , Área Tegmental Ventral/efectos de los fármacos , Animales , Cocaína/administración & dosificación , Cocaína/análogos & derivados , Cocaína/sangre , Trastornos Relacionados con Cocaína/sangre , Trastornos Relacionados con Cocaína/metabolismo , Trastornos Relacionados con Cocaína/patología , Dendritas/efectos de los fármacos , Dendritas/metabolismo , Dendritas/ultraestructura , Inhibidores de Captación de Dopamina/administración & dosificación , Inhibidores de Captación de Dopamina/efectos adversos , Inhibidores de Captación de Dopamina/sangre , Neuronas Dopaminérgicas/efectos de los fármacos , Neuronas Dopaminérgicas/metabolismo , Neuronas Dopaminérgicas/ultraestructura , Neuronas GABAérgicas/metabolismo , Neuronas GABAérgicas/ultraestructura , Masculino , Ratones , Ratones Endogámicos C57BL , Cuerpos Multivesiculares/efectos de los fármacos , Cuerpos Multivesiculares/metabolismo , Cuerpos Multivesiculares/ultraestructura , Subunidades de Proteína/metabolismo , Transporte de Proteínas/efectos de los fármacos , Distribución Aleatoria , Síndrome de Abstinencia a Sustancias/metabolismo , Síndrome de Abstinencia a Sustancias/patología , Síndrome de Abstinencia a Sustancias/fisiopatología , Tirosina 3-Monooxigenasa/metabolismo , Área Tegmental Ventral/metabolismo , Área Tegmental Ventral/fisiopatología , Área Tegmental Ventral/ultraestructuraRESUMEN
Drug addiction remains a substantial health issue with limited treatment options currently available. Despite considerable advances in the understanding of human genetic architecture, the genetic underpinning of complex disorders remains elusive. On the basis of our current understanding of neurobiology, numerous candidate genes have been implicated in the etiology and response to treatment for different addictions. Genome-wide association (GWA) studies have also identified novel targets. However, replication of these studies is often lacking, and this complicates interpretation. The situation is expected to improve as issues such as phenotypic characterization, the apparent "missing heritability," the identification of functional variants, and possible gene-environment (G × E) interactions are addressed. In addition, there is growing evidence that genetic information can be useful in refining the choice of addiction treatment. As genetic testing becomes more common in the practice of medicine, a variety of ethical and practical challenges, some of which are unique to drug addiction, will also need to be considered.
Asunto(s)
Genómica/métodos , Farmacogenética/métodos , Trastornos Relacionados con Sustancias/tratamiento farmacológico , Trastornos Relacionados con Sustancias/genética , Pruebas Genéticas/métodos , Pruebas Genéticas/tendencias , Variación Genética/genética , Genómica/tendencias , Humanos , Metadona/uso terapéutico , Naltrexona/uso terapéutico , Farmacogenética/tendencias , Trastornos Relacionados con Sustancias/diagnósticoRESUMEN
Cocaine administration increases AMPA GluR1 expression and receptor-mediated activation of the ventral tegmental area (VTA). Functionality is determined, however, by surface availability of these receptors in transmitter- and VTA-region-specific neurons, which may also be affected by cocaine. To test this hypothesis, we used electron microscopic immunolabeling of AMPA GluR1 subunits and tyrosine hydroxylase (TH), the enzyme needed for dopamine synthesis, in the cortical-associated parabrachial (PB) and in the limbic-associated paranigral (PN) VTA of adult male C57BL/6 mice receiving either a single injection (acute) or repeated escalating-doses for 14 days (chronic) of cocaine. Acute cocaine resulted in opposing VTA-region-specific changes in TH-containing dopaminergic dendrites. TH-labeled dendrites within the PB VTA showed increased cytoplasmic GluR1 immunogold particle density consistent with decreased AMPA receptor-mediated glutamatergic transmission. Conversely, TH-labeled dendrites within the PN VTA showed greater surface expression of GluR1 with increases in both synaptic and plasmalemmal GluR1 immunogold density after a single injection of cocaine. These changes diminished in both VTA subregions after chronic cocaine administration. In contrast, non-TH-containing, presumably GABAergic dendrites showed VTA-region-specific changes only after repeated cocaine administration such that synaptic GluR1 decreased in the PB, but increased in the PN VTA. Taken together, these findings provide ultrastructural evidence suggesting that chronic cocaine not only reverses the respective depression and facilitation of mesocortical (PB) and mesolimbic (PN) dopaminergic neurons elicited by acute cocaine, but also differentially affects synaptic availability of these receptors in non-dopaminergic neurons of each region. These adaptations may contribute to increased cocaine seeking/relapse and decreased reward that is reported with chronic cocaine use.
Asunto(s)
Cocaína/farmacología , Neuronas/metabolismo , Receptores AMPA/metabolismo , Área Tegmental Ventral/metabolismo , Animales , Dendritas/metabolismo , Dopamina/metabolismo , Relación Dosis-Respuesta a Droga , Masculino , Ratones , Ratones Endogámicos C57BLRESUMEN
There is evidence that the kappa opioid system plays an important role in cocaine addiction and that chronic cocaine administration and withdrawal from chronic cocaine alter kappa opioid receptor (KOPr) density. The present study employed in situ [(35)S]guanosine 5'-O-[gamma-thio]triphosphate acid (GTPgammaS) binding autoradiography to measure KOPr-stimulated activation of G-protein in the caudate putamen, nucleus accumbens core and shell, lateral hypothalamus, basolateral amygdala, substantia nigra compacta, substantia nigra reticulata and ventral tegmental area (VTA), in response to chronic cocaine administration or acute and chronic withdrawal from chronic cocaine. Male Fischer rats were injected i.p. with saline or cocaine three times daily at 1 h intervals in an escalating-dose paradigm for 14 days (from 3x15 mg/kg/injection on days 1-3 up to 3x30 mg/kg/injection on days 10-14). Identically treated separate groups were withdrawn from cocaine or saline for 24 h or 14 days. No significant change in KOPr agonist U-69593-stimulated [(35)S]GTPgammaS was found in the seven regions studied 30 min or 14 days after chronic 14 days escalating-dose binge cocaine administration. However there was an increase in KOPr -stimulated [(35)S]GTPgammaS binding in the VTA (P<0.01) of rats withdrawn for 24 h from chronic cocaine. Our results show a cocaine withdrawal induced increase of KOPr signaling in the VTA, and suggest that the KOPr may play a role in acute withdrawal from cocaine.