Role of Glucocorticoid Receptor in the Relation between Stress and Opiate Addiction

Stressful situations can result in relapse in dependent or abstinent causing reinstatement of drug-seeking. In fact, it has been suggested that activation of the brain stress system results in glucocorticoid release that affects the dopaminergic pathways. Also, the noradrenergic system innervates the extrahypothalamic BSS from the nucleus of tractus solitarius (NTS), resulting in a feedforward loop between the corticotropin-releasing factor (CRF) and noradrenaline (NA) crucial in drug addiction and relapses. Glucocorticoids interact with two receptors: mineralocorticoid receptor (MR) and glucocorticoid receptor (GR) which bind to a GRE site located in tyrosine hydroxylase (TH), resulting in the upregulation of TH synthesis and, finally, increasing dopamine (DA) release in the nucleus accumbens. TH upregulation depends on the phosphorylation of serine 31 and/or serine 40. Previous research has shown that protein kinase C (PKC) activates extracellular signal-regulated kinase (ERK) pathway and in turn phosphorylates serine 31 in the NTS. Besides, cAMP response element binding protein (CREB) is regulated by PKA and PKC. The results shown after pretreating morphine-withdrawn rats with mifepristone and spironolactone (GR and MR antagonists, respectively) suggest that glucocorticoids have a prominent role in addiction because GR would activate ERK and CREB in the NTS, phosphorylating serine 31 and activating TH and indeed noradrenergic release in the paraventricular nucleus (PVN)

A stressz rendszer szerepe az ópiát függőség kialakulásában: idegi, sejtszintű és molekuláris mechanizmusok = Involvement of brain stress system in opiate addiction: neuronal substrates, cellular and molecular mechanisms

1. A morfium függőség és megvonás aktiválja a neuroendokrin és az agyi stresszrendszert. 2. A hipotalamusz paravntrikuláris magjában illetve az ""extended"" amigdalában expresszálódó kortikotropin-releasing hormon (CRH) különböző módon szabályozza a morfium addikciót és megvonást kísérő hormonális, élettani és magatartási (érzelmi) reakciókat. 3. Sejtszinten a cAMP-reponse element binding protein (CREB) és a hozzá csatlakozó ko-regulátor fehérjék, mint pl a foszforilált TORC fontos szerepet játszanak a drogmegvonás kapcsán aktiválódó CRH gén szabályozásában mind a hipotalamuszban, mind az ""extended"" amigdalában. 4. A hipotalamikus és extrahipotalamikus területeket beidegző felszálló noradrenerg és orexinerg pályák különböző mechanizmussal vesznek részt a drogfüggőséggel és a drogmegvonással járó megvonási tünetek kialakításában. 5. A morfium függőséggel és a naloxonnal történő morfium megvonás okozta anyagcsere változások a hipotalamuszban eltérő módon befolyásolják a stresszel és a metabolikus szabályozássaél kapcsolatos neuropaptid gének expresszióját. | 1. Morphine dependence and naloxone-precipitated morphine withdrawal results in activation of the neuroendocrine and brain stress systems in the rat brain. 2. Corticotropin-releasing hormone expressed in the hypophyseotropic cells of the hypothalamus as well as in the extended amygdala plays a differential role in the development of hormonal, physiological, emotional and behavioral changes in addicted animals. 3. cAMP-response element binding protein (CREB) and its co-activators (such as pTORC) play a critical role in activation of corticotropin-releasing hormone gene expression both in the hypothalamus and in the extended amygdala. 4. Ascending noradrenergic and orexinergic pathways innervating hypothalamic and extrahypothalamic sites differentially regulate the development of hormonal, somatic and psychological symptoms of morphine withdrawal. 5. Metabolic changes associated by drug dependence and withdrawal result in differential changes of metabolic and stress-related neuropeptides in the hypothalamus

Efectos de agonistas y antagonistas colinérgicos sobre la temperatura corporal de la rata consciente / por María Victoria Milanés Maquilón ; dirigida por José S. Serrano Molina.

Tesis - Universidad de Murcia.MEDICINA ESPINARDO. DEPOSITO. MU-Tesis 22

Determinación y cuantificación de aztreonam en suero y tejido prostático y vesical por HPLC : administración via intravenosa vs submucosa anal /Gregorio Hita Villaplana ; directora María Victoria Milanés Maquilón.

Tesis-Universidad de Murcia.MEDICINA ESPINARDO. DEPOSITO. MU-Tesis 542.Consulte la tesis en: BCA. GENERAL. ARCHIVO UNIVERSITARIO. T.M.-1607

Modificaciones cardíacas durante la tolerancia-dependencia a opioides / José Ventura Rabadán Díaz ; directoras Mª Luisa Laorden Carrasco, Mª Victoria Milanés Maquilón.

Tesis-Universidad de Murcia.MEDICINA ESPINARDO. DEPOSITO. MU-Tesis 526.Consulte la tesis en: BCA. GENERAL. ARCHIVO UNIVERSITARIO. T.M.-1551

Influencia del estrés prenatal en la ontogenia de receptores y péptidos opioides en el sistema nervioso central de la rata / M. Dolores Sánchez Carretero ; directoras M. Luisa Laorden Carrasco, M. Victoria Milanés Maquilón.

Tesis-Universidad de Murcia.MEDICINA ESPINARDO. DEPOSITO. MU-Tesis 494.Consulte la tesis en: BCA. GENERAL. ARCHIVO UNIVERSITARIO. T.M.-1478

Sex differences between CRF1 receptor deficient mice following naloxone-precipitated morphine withdrawal in a conditioned place aversion paradigm: implication of HPA axis.

Extinction period of positive affective memory of drug taking and negative affective memory of drug withdrawal, as well as the different response of men and women might be important for the clinical treatment of drug addiction. We investigate the role of corticotropin releasing factor receptor type one (CRF1R) and the different response of male and female mice in the expression and extinction of the aversive memory.We used genetically engineered male and female mice lacking functional CRF1R. The animals were rendered dependent on morphine by intraperitoneally injection of increasing doses of morphine (10-60 mg/kg). Negative state associated with naloxone (1 mg/kg s.c.)-precipitated morphine withdrawal was examined by using conditioned place aversion (CPA) paradigm. No sex differences for CPA expression were found in wild-type (n = 29) or CRF1R knockout (KO) mice (n = 29). However, CRF1R KO mice presented less aversion score than wild-type mice, suggesting that CRF1R KO mice were less responsive than wild-type to continuous associations between drug administration and environmental stimuli. In addition, CPA extinction was delayed in wild-type and CRF1R KO male mice compared with females of both genotypes. The genetic disruption of the CRF1R pathway decreased the period of extinction in males and females suggesting that CRF/CRF1R is implicated in the duration of aversive memory. Our results also showed that the increase in adrenocorticotropic hormone (ACTH) levels observed in wild-type (n = 11) mice after CPA expression, were attenuated in CRF1R KO mice (n = 10). In addition, ACTH returned to the baseline levels in males and females once CPA extinction was finished.These results suggest that, at least, CPA expression is partially due to an increase in plasma ACTH levels, through activation of CRF1R, which can return when CPA extinction is finished

Conditioned aversive memory associated with morphine withdrawal increases brain derived neutrophic factor in dentate gyrus and basolateral amygdala

Morphine has been shown to increase the expression of brain-derived neurotrophic factor (BDNF) in the brain. However, little is known about the effect of conditioned naloxone-precipitated morphine withdrawal on BDNF and its precursor protein, proBDNF. We used the conditioned-place aversion (CPA) paradigm to evaluate the role of corticotropin-releasing factor (CRF)/CRF1 receptor signalling on the BDNF expression and corticosterone plasma levels after CPA expression and extinction. Male mice were rendered dependent on morphine and injected acutely with naloxone before paired to confinement in a naloxone-associated compartment. The expression of BDNF and proBDNF in the dentate gyrus (DG) and basolateral amygdala (BLA) was measured in parallel with the corticosterone plasma levels with and without CRF1 receptor blockade. Mice subjected to conditioned naloxone-induced morphine-withdrawal showed an increased expression of BDNF (in DG and BLA) in parallel with an enhancement of corticosterone plasma levels. These results demonstrated that BDNF expression together with the increased activity of hypothalamic-pituitary-adrenocortical (HPA) axis are critical to the acquisition of aversive memory. However, we have observed a decrease in corticosterone plasma levels and BDNF expression after CPA extinction reaffirming the importance of BDNF in the maintenance of aversive memory. In addition, the pre- treatment with the CRF1 receptor antagonist CP-154,526 before naloxone conditioning session impaired morphine withdrawal-induced aversive memory acquisition, the increased corticosterone plasma levels and the expression of BDNF observed after CPA expression in the DG and BLA. Altogether present results suggesting a clear connexion between HPA axis and BDNF in the formation and extinction of aversive memory

Conditioned aversive memory associated with morphine withdrawal increases brain-derived neurotrophic factor in dentate gyrus and basolateral amygdala.

Morphine has been shown to increase the expression of brain-derived neurotrophic factor (BDNF) in the brain. However, little is known about the effect of conditioned naloxone-precipitated morphine withdrawal on BDNF and its precursor protein, proBDNF. We used the conditioned-place aversion (CPA) paradigm to evaluate the role of corticotropin-releasing factor (CRF)/CRF1 receptor signalling on the BDNF expression and corticosterone plasma levels after CPA expression and extinction. Male mice were rendered dependent on morphine and injected acutely with naloxone before paired to confinement in a naloxone-associated compartment. The expression of BDNF and proBDNF in the dentate gyrus (DG) and basolateral amygdala (BLA) was measured in parallel with the corticosterone plasma levels with and without CRF1 receptor blockade. Mice subjected to conditioned naloxone-induced morphine-withdrawal showed an increased expression of BDNF (in DG and BLA) in parallel with an enhancement of corticosterone plasma levels. These results demonstrated that BDNF expression together with the increased activity of hypothalamic-pituitary-adrenocortical (HPA) axis are critical to the acquisition of aversive memory. However, we have observed a decrease in corticosterone plasma levels and BDNF expression after CPA extinction reaffirming the importance of BDNF in the maintenance of aversive memory. In addition, the pre- treatment with the CRF1 receptor antagonist CP-154,526 before naloxone conditioning session impaired morphine withdrawal-induced aversive memory acquisition, the increased corticosterone plasma levels and the expression of BDNF observed after CPA expression in the DG and BLA. Altogether present results suggesting a clear connexion between HPA axis and BDNF in the formation and extinction of aversive memory

Binge ethanol and MDMA combination exacerbates HSP27 and Trx-1 (biomarkers of toxic cardiac effects) expression in right ventricle

Aims Oxidative stress caused by exposure to drugs of abuse such as ethanol or 3, 4 methylenedioxymethamphetamine (MDMA) may derive from direct or indirect effects in many organs including the heart. The aim of the present work was to evaluate cardiac sympathetic activity and the expression and activation of two antioxidant proteins: heat shock protein27 (HSP27) and thioredoxin-1 (Trx-1) after voluntary binge ethanol consumption, alone and in combination with MDMA. Material and Methods Adolescent mice received MDMA, ethanol or both. Drinking in the dark (DID) procedure was used as a model of binge. HSP27 expression and phosphorylation at serine 82 (pHSP27), Trx-1 expression, tyrosine hydroxylase (TH) and TH phosphorylated at serine 31 (pTH) were evaluated in adolescent mice 48h and 7 days after treatments in the right ventricle. TH, HSP27 expression and phosphorylation and Trx-1 expression were measured by quantitative blot immunolabeling using specific antibodies. Key Findings The expression of HSP27, pHSP27, Trx-1, total TH and pTH in the right ventricle was increased after binge ethanol or MDMA alone. In addition, the combination of binge ethanol+MDMA enhanced TH expression and phosphorylation versus their individual administration. Significance These results indicate that this combination could produce higher activation of sympathetic pathways, which could trigger an increased cell stress. On the other hand, increased HSP27, 3 pHSP27 and Trx-1 expression in the right ventricle by ethanol+MDMA could be a protective mechanism to reduce the adverse effects of oxidative stress caused by both drugs of abuse