Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study was undertaken to investigate the potential antidepressant-like properties of SL65.0155, a serotonin 5-HT(4) receptor partial agonist, in male rats of the Wistar strain tested in the forced swim test (FST), an experimental model widely used to assess antidepressant-like activity. The expression of hippocampal neurotrophic factors, such as the brain-derived neurotrophic factor (BDNF), the phosphorilated cAMP response element-binding protein (p-CREB), the B cell lymphoma-2 (Bcl-2), the Bax and the vascular endothelium growth factor (VEGF) were also evaluated by Western Blot analysis. Different groups of rats received intraperitoneally (i.p.) injections of SL65.0155 (0.1, 0.5 and 1 mg/kg), clomipramine (50 mg/kg), citalopram (15 mg/kg) or vehicle, respectively, 24, 5 and 1 h prior to the FST. Compared to the control group, SL65.0155 (0.5 and 1 mg/kg), clomipramine or citalopram injected animals showed an increased swimming and climbing behavior and reduced immobility time in the FST. Interestingly, this effect was not due to changes in the locomotor activity since all treated groups failed to show any change in motor ability as assessed in the open field test. Western blot analysis of hippocampal homogenates showed an enhancement of p-CREB, BDNF Bcl-2 and VEGF protein levels in SL65.0155 treated groups, but not in citalopram or clomipramine treated groups, used here as positive control. No change was found in Bax expression in any treated group. These findings give further support to the hypothesis that the stimulation of serotonin 5-HT(4) receptors may be a therapeutic target for depression.
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PMID:Antidepressant properties of the 5-HT4 receptor partial agonist, SL65.0155: behavioral and neurochemical studies in rats. 1959 38

Chronic mild stress (CMS) is suggested to develop dysregulation of the limbic-hypothalamic-pituitary-adrenal (LHPA) stress circuit. Icariin, a major constituent of flavonoids isolated from Epimedium brevicornum, has been previously confirmed to rescue the HPA axis abnormalities in animal models of depression. However, antidepressant treatment of icariin on corticotropin-releasing factor (CRF) system within the LHPA stress circuit and its interaction with serotonergic receptor are still seldom studied in CMS model of animals. The present study further investigated the effects of CMS procedure and subsequent icariin treatment on mRNA and protein levels of CRF, CRF receptor 1 (CRFR1) and CRF binding protein (CRFBP), as well as sucrose intake in rats. Moreover, the levels of cyclic adenosine 3',5'-monophosphate (cAMP) response element binding protein (CREB), glucocorticoid receptor (GR) and 5-hydroxytryptamine 1A receptor (5-HTR1A) in hypothalamus, hippocampus and frontal cortex were simultaneously evaluated for their participations in CRF system in this model. We found that CMS procedure significantly increased CRF expression levels in the brain regions, and decreased GR and 5-HTR1A in hippocampus and frontal cortex, with sucrose intake reduction representing the hedonic deficit in rats. Icariin restored these alterations in CMS rats. These results confirmed the hypothesis that icariin exerted antidepressant-like effect via its regulation of central CRF system. And hippocampus was suggested as an important neural area controlling the LHPA stress circuit in icariin-treated CMS rats. These findings for the first time proved that the potential molecular mechanism of antidepressant action of icariin was targeted on the interaction of the LHPA stress circuit and serotonergic function in CMS rats.
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PMID:Icariin attenuates chronic mild stress-induced dysregulation of the LHPA stress circuit in rats. 1963 74

Depression is one of the most common and most devastating psychiatric disorders. Although a variety of treatment strategies is available, a major problem in its therapy consists of the unpredictability of the drug response. Furthermore, most antidepressant drugs, which usually increase 5-HT and norepinephrine levels in the synaptic cleft, are likely to produce side effects. Therefore, the quest for new options in antidepressant treatment is urgent. A novel therapeutic approach beyond manipulating the neurotransmitter-receptor interaction consists of targeting signal transduction and gene expression pathways. One of the best investigated pathways is the cyclic AMP second messenger system which ultimately influences gene expression by activating the transcription factor cyclic AMP response element binding protein via phosphorylation. There is evidence that this cAMP-PKA-CREB system is disturbed in depression and that an increased cyclic AMP response element binding protein activity may result in an improved neural plasticity, which in turn could contribute to amelioration of the clinical symptoms of depression.
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PMID:Cyclic AMP response element-binding protein and depression. 1981 Aug 66

Increasing evidence suggests that depression may be both a cause and consequence of neurological disorders such as Alzheimer's disease (AD), and that anti-depressants could provide an alternative strategy to current AD therapies. Association of side effect and herbal-drug interaction with conventional anti-depressant and St. John's wort warrant investigating new anti-depressant drugs. Anti-depressant effects of ginkgo biloba extract (EGb 761) have been demonstrated in animal models of depression and in human volunteers. We report here that ginkgo flavonols quercetin and kaempferol stimulates depression-related signaling pathways involving brain-derived neurotrophic factor BDNF/phosphorylation of cyclic AMP response element binding protein CREB/postsynaptic density proteins PSD95, and reduces amyloid-beta peptide (Abeta) in neurons isolated from double transgenic AD mouse (TgAPPswe/PS1e9). In addition, enhanced BDNF expression and reduction of Abeta oligomers was confirmed in hippocampus of the double transgenic mice administered with flavonol, which correlates with cognitive improvement behaviors in these mice. The present results suggest that stimulating BDNF and reducing Abeta toxicity by natural flavonols provide a therapeutic implication for treatment of AD.
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PMID:Anti-depressant natural flavonols modulate BDNF and beta amyloid in neurons and hippocampus of double TgAD mice. 1991 99

Stressors differ in their physiological and behavioral outcomes. One of the major mechanisms by which stressors affect the brain and behavior is alteration in neuronal plasticity. We investigated in the rat the effects of a single exposure to psychophysical (electrical foot shock) vs. psychological (social defeat) stressors on anxiety- and depression-related behaviors, serum levels of corticosterone and the expression of plasticity-related genes CAM-L1, CREB, GAP-43, and laminin in the prefrontal cortex (PFC), the amygdala and the hippocampus. Rats were examined for 24 h or 1 week after the exposure to stress. Footshocks enhanced anxiety-related behaviors, whereas social defeat induced depression-related behaviors at both time points and less pronounced anxiety 1 week post-exposure. Serum corticosterone concentrations were enhanced 24 h after shocks, but only 1 week after exposure to the social stressor. Moreover, the shock-stressed rats exhibited decreased CAM-L1 protein level in the hippocampus 24 h post-exposure and decreased GAP-43 protein level in the PFC 1 week post-exposure. By contrast, the social stressor enhanced expression of the plasticity-related proteins in the amygdala and the hippocampus, mostly 1 week after the exposure. These results indicate stressor-specific time-dependent changes in different neuronal pathways, and suggest consideration of a cause-specific approach to the treatment of stress-related disorders.
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PMID:Physical stress differs from psychosocial stress in the pattern and time-course of behavioral responses, serum corticosterone and expression of plasticity-related genes in the rat. 1992 44

Increasing data indicate that brain endocannabinoid system plays a role in the effects of antidepressant medications. Here we examined the effect of in vivo exposure to the selective serotonin uptake inhibitor fluoxetine on cannabinoid type 1 (CB(1)) receptor density and functionality in the rat prefrontal cortex (PFC) and cerebellum. Long-term treatment with fluoxetine (10 mg/kg/day) enhanced CB(1) receptor inhibition of adenylyl cyclase (AC) in the PFC and reduced it in the cerebellum without altering receptor density and agonist stimulation of guanosine 5'-O-(3-[(35)S]thio) triphosphate ([(35)S]GTP gamma S) in either area. Analysis of [(35)S]GTP gamma S-labeled G alpha subunits allowed for the detection of up-regulated CB(1) receptor coupling to G alpha(i2), G alpha(i3) in the PFC, and reduced coupling to G alpha(i3) in the cerebellum of fluoxetine-treated rats. Concomitant administration of the 5-HT(1A) receptor antagonist N-[2-[4- (2-methoxyphenyl)-1-piperazinyl]ethyl]-N-2-pyridinylcyclohexanecarboxamide maleate (WAY100635; 0.1 mg/kg/day) reduced fluoxetine-induced modulation of CB(1) receptor coupling to G alpha subunits and AC in the PFC but not in the cerebellum. These results indicate that increased CB(1) receptor signaling at the G alpha(i)-AC transduction level is a long-term adaptation induced by fluoxetine in the PFC and point to a role for 5-HT(1A) receptors in this effect. Basal AC activity, protein kinase A (PKA) catalytic subunit expression, and phospho-cAMP response element-binding protein (pCREB)/CREB ratio were also up-regulated in the PFC of fluoxetine-treated animals, whereas no differences were detected in the cerebellum. It is interesting that long-term Delta(9)-tetrahydrocannabinol treatment did not elicit antidepressant-like effects or modulated behavioral responses of fluoxetine in an animal model of depression (olfactory bulbectomy). These data suggest that altered signal transduction through CB(1) receptors in the PFC may participate in the regulation of the AC-PKA-CREB cascade induced by fluoxetine in this brain area.
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PMID:Long-term fluoxetine treatment modulates cannabinoid type 1 receptor-mediated inhibition of adenylyl cyclase in the rat prefrontal cortex through 5-hydroxytryptamine 1A receptor-dependent mechanisms. 1999 40

Studies have shown that maternal chronic stress or depression is linked to an increased risk for affective disorders in progeny. However, the impact of maternal chronic stress before pregnancy on their progeny in animal models has not been well studied. We investigated the behaviors and the neurobiology in 60-day-old male progeny of maternal rats exposed to a 21-day chronic unpredictable stress (CUS) before pregnancy, with male progeny of unstressed maternal rats as the control. Sucrose consumption test showed that both sucrose intake and sucrose consumption percentage of the CUS progeny were lower than those of the control progeny (P<0.05). The number of times crossing the removed hidden platform in the CUS progeny was significantly fewer than that in the control progeny in Morris water maze test (P<0.05). The level of 5-hydroxytryptamine (5-HT) in the hypothalamus was reduced but the level of norepinephrine (NE) in the hippocampus was increased in CUS progeny when compared to the control (P<0.05). Western blotting showed that the relative level of phosphorylated CREB (P-CREB) in the CUS progeny was lower than that in the control progeny (P<0.05). There were significant positive correlations between sucrose consumption percentage and the level of 5-HT in hypothalamus P<0.05) or the level of P-CREB in hippocampus (P<0.05). In conclusion, depression or stressful events before pregnancy was also associated with high risk of depression in progeny, and the down-regulation of P-CREB in the hippocampus might be one of the mechanisms underlying depression in the CUS progeny.
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PMID:Behavioral and neurobiological studies on the male progeny of maternal rats exposed to chronic unpredictable stress before pregnancy. 2001 28

Recent biological studies suggest the existence of the common pathophysiological aspects in alcoholism and depression. Postmortem studies have revealed the impairment of cAMP signaling in the patients with alcoholism. The similar alteration of cAMP signaling was also reported in postmortem brains of depressed patients. In this study, we supported the notion that neurogenesis would be essential in pathophysiology of both alcoholism and depression. Alcohol affected the function of neural stem cells (NSCs) and decreased neurogenesis at doses which did not affects cell survival, and treatment of antidepressant or moodstabilizer rescued the alcohol-induced suppression of neurogenesis. As the key mechanism of NSC differentiation change by ethanol and psychotropics, we focused on the transcriptional repressor, NRSF/REST activity change. Our in vitro studies demonstrated the NRSF/REST activation by ethanol and suppressive effect of antidepressants and lithium against its activation by ethanol. We further described the ERK reduction and ER stress in the cellular mechanism of NRSF/REST activation. All these findings suggested that cAMP-CREB cascade reduction and NRSF/REST activation may be common underlying mechanisms in the pathophysiology of alcoholism and depression.
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PMID:The common aspects of pathophysiolgy of alcoholism and depression. 2007 63

The transcription factor CREB regulates adaptive responses like memory consolidation, addiction, and synaptic refinement. Recently, chronic psychosocial stress as animal model of depression has been shown to stimulate CREB transcriptional activity in the brain; this stimulation was prevented by treatment with the antidepressant imipramine, which inhibits both noradrenaline and serotonin reuptake. However, it was unknown whether the selective inhibition of serotonin reuptake is sufficient for inhibition of stress-induced CREB activation, as it is for the clinical antidepressant effect. Therefore, the effect of two selective serotonin reuptake inhibitors (SSRIs), citalopram and fluoxetine, was examined in this study. Transgenic CRE-luciferase reporter gene mice were used to monitor gene transcription directed by the CREB DNA binding site (CRE) in vivo. Chronic psychosocial stress for 25days stimulated CRE/CREB-directed luciferase expression in the hippocampus and other brain regions. When applied alone to non-stressed mice, citalopram caused a transient increase after 24h that was lost after 21days of treatment, whereas fluoxetine had no effect after 24h and produced an inhibition in the pons and hypothalamus after 21days of treatment. However, both citalopram and fluoxetine treatment completely abolished the increase in CRE/CREB-directed transcription induced by chronic psychosocial stress. As indicated by Western blots, the changes in CRE/CREB-directed transcription were accompanied by corresponding changes in the phosphorylation of CREB at serine-119. These results further emphasize the role of CREB in stress-induced gene expression and suggest furthermore that inhibition of stress-induced CREB activity may be a common mechanism of action of SSRIs underlying their antidepressive effect.
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PMID:A common mechanism of action of the selective serotonin reuptake inhibitors citalopram and fluoxetine: reversal of chronic psychosocial stress-induced increase in CRE/CREB-directed gene transcription in transgenic reporter gene mice. 2012 21

Nitric oxide (NO), physical exercise and/or antidepressant drugs, through the increased release of norepinephrine and brain-derived neurotrophic factor (BDNF), have been shown to exert profound protective, pro-survival effects on neurons otherwise compromised by injury, disease, prolonged stress, and subsequent depression in vivo. We sought, therefore, to evaluate such survival and neuroprotection in hippocampal neurons in culture, which, in an analogous model of in vivo cellular stress, was deprived of several vital nutrients. We assessed pro-survival outcomes following the application of norepinephrine or the noradrenergic partial agonist, clonidine, a general nitric oxide synthase inhibitor and NO donor, using a cell survival assay and quantitative Western blotting of the survival signaling molecules, BDNF, P-CREB, P-Akt, and P-MAPK in hippocampal neuronal lysates. We demonstrate that norepinephrine, clonidine, the NO donor and various combinations of these drugs increased cell survival and the immunoreactivity of the four survival signaling molecules in the face of nutrient deprivation stress, whereas the NO synthase inhibitor, and each of several survival signaling pathway inhibitors all decreased cell survival even below that of controls without nutrient supplementation. These results demonstrate that conditions that make cells vulnerable to environmental/toxic insult can be offset by norepinephrine and its related drugs or by NO donors and exacerbated by drugs that specifically inhibit a key survival signaling pathway. These results indicate that pharmacological intervention can promote neuroprotection and survival signaling in the face of nutrient withdrawal, but that this may require that several pathways remain intact.
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PMID:Norepinephrine and nitric oxide promote cell survival signaling in hippocampal neurons. 2014 90


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