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)

A confluence of evidence indicates that prolonged elevation in gluco-corticoid level may result in disturbances of mood and cognition. In Cushing's syndrome, hypersecretion of cortisol is associated with a high incidence of depression, impairment in memory and hippocampal atrophy. Pharmacological usage of glucocorticoids is similarly productive of mood change and memory deficit. In patients with endogenous depression, hypercortisolaemia is associated with cognitive dysfunction and possibly a decrease in hippocampal volume. In each of these conditions, reduction of glucocorticoid level, either through discontinuation of steroid treatment or through usage of agents that block glucocorticoid synthesis, ameliorates the adverse behavioural effects. Traditional antidepressant agents may, in addition, stabilise mood through actions on the hypothalamic-pituitary adrenocortical (HPA) system. Although clinical usage of the currently available antiglucocorticoid drugs is limited by significant adverse side effect profiles, development of drugs specifically targeting the glucocorticoid receptor may lead to innovative strategies in the treatment of mood disorders.
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PMID:Antiglucocorticoid drugs in the treatment of depression. 1177 85

Ageing of the brain is an important factor in overall ageing and mortality, and new insights have clarified the relationship between neuroregulation and ageing. First, neuronal loss in normal ageing is now known to be a minor change. Loss of synapses through dystrophic neuronal change is the hallmark of normal ageing. Second, similar dystrophic changes occur in the brain with chronic stress. In both instances, forebrain sites experience loss of synaptic input from brainstem regulatory nuclei. Third, functional ageing is attributed in part to lifetime stress, under the concept of 'allostatic load'. Being inseparable from the functions of appraising and responding to stress, the brain is an ultimate mediator of stress-related mortality, through hormonal changes that lead to proximate pathologies like hypertension, glucose intolerance, cardiovascular disease and immunological impairment. In chronic stress the brain shows clear allostatic compensations that lead to pathology. Two subtle and chronic mechanisms that may mediate brain pathology and accelerated ageing in chronic stress are proposed. These are abnormal glucocorticoid receptor (GR) occupancy over the 24 h cycle, and elevated body temperature. These factors lead to GR-mediated tissue changes and to acceleration of general cellular ageing mechanisms. Human depression is discussed as an exemplary demonstration of these principles.
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PMID:Ageing, stress and the brain. 1185 92

Overactivity of the hypothalamic-pituitary-adrenal (HPA) axis has been frequently described in depression. Due to the closed-loop nature of the HPA axis, one possible cause of this overactivity may be a defect in negative feedback regulation, in particular an abnormality of the glucocorticoid receptor (GR). In the present study, the vasoconstrictor response to the topical glucocorticoid, beclomethasone, was used to examine GR function in depression. Topical beclomethasone was applied in four concentrations (10 microl each of 3, 10, 30 and 100 microg/ml) to the forearms of 22 subjects with major depression and their age- and sex-matched controls. Skin blanching responses were compared between the depressed and control groups and, within the depressed group, on the basis of the modified dexamethasone suppression test (DST), between cortisol suppressors and non-suppressors. Depressed subjects demonstrated a significantly reduced vasoconstrictor response compared to controls (P=0.0001). No difference was detected between cortisol suppressors and non-suppressors in their skin blanching responses. These findings suggest that peripheral GR function is abnormal in depression but that the reduced vasoconstrictor response to beclomethasone is not necessarily a secondary effect of hypercortisolaemia or HPA axis overactivity.
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PMID:Vasoconstrictor response to topical beclomethasone in major depression. 1191

Various effects of antidepressant drugs on gene transcription have been described and altered gene expression has been proposed as being a common biological basis underlying depressive illness. One target for the common action of antidepressants is a modifying effect on the regulation of postreceptor pathways and genes related to the cAMP cascade. Recent studies have demonstrated that long-term antidepressant treatment resulted in sustained activation of the cyclic adenosine 3',5'-monophosphate system and in increased expression of the transcription factor cAMP response element binding protein (CREB). A transgenic animal model of depression with impaired glucocorticoid receptor function was used to investigate the effect of chronic antidepressant treatments on CREB expression in different brain areas. Wild-type and transgenic mice received one administration of saline, desipramine, or fluoxetine, daily for 21 days. The effects of antidepressants on CREB mRNA were analyzed using a sensitive RNase protection assay. Antidepressant treatment resulted in a neuroanatomically and animal specific expression pattern of CREB. Our findings suggest that life-long central glucocorticoid receptor dysfunction results in an altered sensitivity with respect to the effects of antidepressants on the expression of CREB.
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PMID:Altered regulation of CREB by chronic antidepressant administration in the brain of transgenic mice with impaired glucocorticoid receptor function. 1192 85

Glucocorticoids are key elements in the maintenance of an organism's homeostasis, a dynamic balance that is constantly challenged by internal and external stressors. Chronic exposure to elevated glucocorticoids may induce profound effects on an individual's physical and mental well-being. Therefore, a complex neuroendocrine system, the limbic-hypothalamo-pituitary-adrenocortical (LHPA) axis, exists to regulate glucocorticoid homeostasis. Dysregulation of the LHPA axis has been linked to numerous psychiatric disorders, including eating disorders, anxiety, depression, posttraumatic stress disorder, memory impairment, neurodegenerative disorders, and even Alzheimer disease. At a molecular level, the actions of glucocorticoids are mediated by two different cytoplasmic receptors, the mineralocorticoid receptor and the glucocorticoid receptor. These corticosteroid receptors are heteromeric complexes found in dynamic association with a still growing number of chaperone proteins and other factors mediating their actions. Because this dynamic association is extremely sensitive to changes in cellular environment, energy, and metabolic state, we hypothesize that these corticosteroid receptors act as "sensor" signal transducers critical for homeostasis. In this review, we focus on the interplay among protein folding, transport, and function of the corticosteroid receptors at the cellular level, which provides a foundation for understanding the pathogenesis of glucocorticoid resistance or hypersensitivity, causing imbalances in the LHPA axis, and possibly triggering psychiatric disorders.
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PMID:Corticosteroid receptors: a dynamic interplay between protein folding and homeostatic control. Possible implications in psychiatric disorders. 1239 67

Macrophages produced proinflammatory cytokines and inflammatory responses can cause many symptoms of depression, including direct stimulation of the HPA axis and secretion of cortisol. In depressed patients, hypercortisolism has been well described as one of the major symptoms and also as the cause for hippocampal atrophy and memory impairment. In this paper, the relationships between thymectomy, increased IL-1 levels, and changes in corticosterone and neurotransmitter concentrations in rats are discussed, as well as their implications for memory impairments and depression. In thymectomized rats, deficits in both spatial and fear conditioned memory have been observed. Thymectomy decreases noradrenaline and dopamine levels, and increases serotonergic neurotransmission in limbic areas, without affecting corticosterone concentrations. In a depression model, thymopeptides or IL-2 treatment significantly attenuated changes in behavior, lymphocyte proliferation and neurotransmitters caused by bulbectomy. The reduction of thymic functions may increase IL-1 synthesis. Central IL-1beta administration impairs rat's spatial memory in the Morris water maze and 8 arms radial maze, but enhances conditioned memory in the passive avoidance. These changes can be reversed by either IL-1 receptor antagonist or a glucocorticoid receptor antagonist (RU 486). Furthermore, IL-1-induced changes in some neurotransmitter systems are similar to those observed in thymectomized rats. However, both acute and sub-chronic IL-1 administration increases plasma corticosterone concentrations. Together, these findings suggest that changes in the function of the thymus gland may play an important role in the unbalance between macrophages, cytokines, and lymphocytes, which induces neurotransmitter and neuroendocrine changes, and memory disturbances in depressive illness.
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PMID:The effect of thymectomy and IL-1 on memory: implications for the relationship between immunity and depression. 1240 69

Psychiatric diseases are genetically complex and consequently, altered programs of gene expression have been hypothesized as the molecular basis of psychopathology. Since transcription factors represent the final communicative link between receptor activation and the orchestration of programs of gene expression, they are prime targets for studies on both the pharmacotherapy and the etiology of depression. The cyclic AMP response element binding protein (CREB) and the glucocorticoid receptor (GR) are altered by chronic treatment with antidepressants. Since it is phosphorylated CREB (pCREB) that determines its transcriptional activity, it is pertinent that some antidepressants have been shown to reduce pCREB in brain in vivo and in tissue culture in vitro. Moreover, pCREB is down-regulated in human fibroblasts from patients with major depression and in postmortem brain of suicide victims with a history of depression. With regard to GR, its mRNA, immunoreactivity, density and cytoplasmic-nuclear translocation are increased by antidepressants. While transcription factor mediated programs of gene expression relevant to either the pharmacotherapy or the etiology of depression are still largely elusive, studies utilizing modern technologies such as differential display and cDNA microarrays promise to lead eventually to the identification of structure and function of psychopathologically relevant target genes.
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PMID:The role of CREB and other transcription factors in the pharmacotherapy and etiology of depression. 1245 79

Corticosteroids regulate a variety of essential physiological functions, such as mineral balance and stress. The great interest in these steroids, especially the glucocorticoids, stems from roles they are thought to play in neuropsychiatric disorders, such as severe depression and anxiety.The development of glucocorticoid receptor (GR) ligands which are appropriately labeled with short-lived positron-emitting radioisotopes would allow the non-invasive in-vivo imaging and mapping of brain GRs by means of positron emission tomography (PET). In this context we have synthesized a series of novel arylpyrazolo steroids exhibiting different substitution patterns at the D-ring of the steroid skeleton, as ligands for brain GRs. Special attention was given to 4-fluorophenyl pyrazolo steroids, which are known to display high binding affinity toward the GR. The compounds were evaluated in a competitive radiometric receptor binding assay to determine their relative binding affinities (RBA) to the GR. Some compounds show good binding affinities of up to 56% in comparison to dexamethasone (100%). In initial experiments, selected candidates were labeled with the positron emitter fluorine-18 and in one case with the gamma-emitter iodine-131.
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PMID:Synthesis of novel arylpyrazolo corticosteroids as potential ligands for imaging brain glucocorticoid receptors. 1260 9

Clinical and preclinical studies have gathered substantial evidence that stress response alterations play a major role in the development of major depression, panic disorder, and post-traumatic stress disorder. The stress response, the hypothalamic pituitary adrenocortical (HPA) system and its modulation by corticotropin-releasing hormones (CRH),corticosteroids,and their receptors, and the roles of natriuretic peptides and neuroactive steroids are described. We review the role of the HPA system in major depression, panic disorder, and post-traumatic stress disorder and its possible relevance for treatment. Impaired glucocorticoid receptor function in major depression is associated with an excessive release of neurohormones such as CRH, to which a number of signs and symptoms characteristic of depression can be ascribed. In panic disorder, a role of central CRH in panic attacks has been suggested. Atrial natriuretic peptide (ANP) is causally involved in sodium lactate-induced panic attacks. Furthermore, preclinical and clinical data on its anxiolytic activity suggest that nonpeptidergic ANP receptor ligands may be potentially useful in the treatment of anxiety disorders. Post-traumatic stress disorder is characterized by a peripheral hyporesponsive HPA system and elevated CRH concentrations in the CSF. This dissociation is probably related to an increased risk of this disorder. We further review recent data that describe an important role of GABA(A)-receptor modulatory,3 alpha-reduced neuroactive steroids in major depression, anxiety, and its treatment. Antidepressants are effective in both depression and anxiety disorders and have major effects on the HPA system,especially on glucocorticoid and mineralocorticoid receptors. Normalization of HPA system abnormalities is a strong predictor of the clinical course, at least in major depression and panic disorder. Currently,CRH-R1 or glucocorticoid receptor antagonists and ANP receptor agonists are being studied and may provide future treatment options more closely related to the pathophysiology of these disorders.
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PMID:[The neuroendocrinology of stress and the pathophysiology and therapy of depression and anxiety]. 1262 45

There is growing evidence from neuroimaging and ostmortem studies that severe mood disorders, which have traditionally been conceptualized as neurochemical disorders, are associated with impairments of structural plasticity and cellular resilience. It is thus noteworthy that recent preclinical studies have shown that critical molecules in neurotrophic signaling cascades (most notably cyclic adenosine monophosphate [cAMP] response element binding protein, brain-derived neurotrophic factor, bcl-2, and mitogen activated protein [MAP] kinases) are long-term targets for antidepressant agents and antidepressant potentiating modalities. This suggests that effective treatments provide both trophic and neurochemical support, which serves to enhance and maintainnormal synaptic connectivity, thereby allowing the chemical signal to reinstate the optimal functioning of critical circuits necessary for normal affective functioning. For many refractory patients, drugs mimicking "traditional" strategies, which directly or indirectly alter monoaminergic levels, may be of limited benefit. Newer "plasticity enhancing" strategies that may have utility in the treatment of refractory depression include N-methyl-D-aspartate antagonists, alpha-amino-3-hydroxy-5-methylisoxazole propionate (AMPA) potentiators, cAMP phosphodiesterase inhibitors, and glucocorticoid receptor antagonists. Small-molecule agents that regulate the activity f growth factors, MAP kinases cascades, and the bcl-2 family of proteins are also promising future avenues. The development of novel, nonaminergic-based therapeutics holds much promise for improved treatment of severe, refractory mood disorders.
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PMID:Enhancing neuronal plasticity and cellular resilience to develop novel, improved therapeutics for difficult-to-treat depression. 1270 57


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