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

Electroconvulsive seizures (ECS) are used for therapy of pharmacoresistent depression and are supposed to induce long-lasting neuronal alterations in morphology and gene expression. In this study, we have investigated the phosphorylation of the transcription factor protein c-Jun at its serine 73 residue by immunohistochemistry and the activity of the c-Jun N-terminal kinase 1 (JNK1) by immunocomplex assay following repetitive ECS in adult rats. In untreated controls, nuclear c-Jun immunoreactivity, but not N-terminal phosphorylation, was present in a variety of neuronal populations including the hippocampus, the temporobasal cortex and the amygdalar complex. Daily ECS for 1, 5 or 10 days (1x, 5x or 10x ECS) did not alter the expression of c-Jun but caused a substantial N-terminal phosphorylation of c-Jun (phospho-c-Jun). Nuclear phospho-c-Jun immunoreactivity was maximal within 15 min following ECS, and became absent after 30 min. The highest levels of phospho-c-Jun labeling were found after 1x ECS in the amygdalar complex, the dorsomedial hypothalamus and the piriform cortex. The inducibility of c-Jun N-terminal phosphorylation was preserved in the medial amygdala and piriform cortex, but significantly declined in the basal amygdala and medial hypothalamus with progressive ECS stimulation. One single ECS 3 or 5 days following 10x ECS yielded a pattern of phospho-c-Jun as seen following 10x ECS; thus, a lag of 5 days was not sufficient to provoke the initial level of N-terminal phosphorylation of c-Jun. In the rostral hippocampus, c-Jun was not phosphorylated at any investigated time inspite of its high constitutive expression. In some contrast with this compartment-specific phosphorylation of c-Jun, immunocomplex assays revealed that the JNK1 activity was strongly enhanced in both amygdala and hippocampus. Our findings demonstrate that rapid JNK activation and phosphorylation of c-Jun as stand-by transcription factor characterize the beginning of neuroplastic changes, e.g., following ECS, a classic treatment of mental disorders. The N-terminal phosphorylation is compartment specific and can habituate following repetitive stimulation suggesting that the differential activation of the JNK/c-Jun axis is part of the neuronal strategy to integrate transynaptic excitation.
 ...
PMID:Repetitive electroconvulsive seizures induce activity of c-Jun N-terminal kinase and compartment-specific desensitization of c-Jun phosphorylation in the rat brain. 1032 Jul 87

The related small GTPases Ras and Rap1 are important for signaling synaptic AMPA receptor (-R) trafficking during long-term potentiation (LTP) and long-term depression (LTD), respectively. Rap2, which shares 60% identity to Rap1, is present at excitatory synapses, but its functional role is unknown. Here, we report that Rap2 activity, stimulated by NR2A-containing NMDA-R activation, depresses AMPA-R-mediated synaptic transmission via activation of JNK rather than Erk1/2 or p38 MAPK. Moreover, Rap2 controls synaptic removal of AMPA-Rs with long cytoplasmic termini during depotentiation. Thus, Rap2-JNK pathway, which opposes the action of the NR2A-containing NMDA-R-stimulated Ras-ERK1/2 signaling and complements the NR2B-containing NMDA-R-stimulated Rap1-p38 MAPK signaling, channels the specific signaling for depotentiating central synapses.
 ...
PMID:Rap2-JNK removes synaptic AMPA receptors during depotentiation. 1595 19

Alcohol dehydrogenase (ADH), which oxidizes ethanol into acetaldehyde, exacerbates ethanol-induced cardiac depression, although the mechanism of action remains unclear. This study was designed to examine the impact of antioxidant catalase (CAT) on cardiac contractile response to ethanol and activation of stress signaling. ADH-CAT double transgenic mice were generated by crossing CAT and ADH lines. Mechanical, intracellular Ca(2+) properties and reactive oxygen species generation were measured in ventricular myocytes. ADH-CAT, ADH, CAT and wild-type FVB myocytes exhibited similar mechanical and intracellular Ca(2+) properties. ADH or ADH-CAT myocytes had higher acetaldehyde-producing ability. Ethanol (80-640 mg/dl) suppressed FVB cell shortening and intracellular Ca(2+) transients with maximal inhibitions of 43.5 and 45.2%, respectively. Ethanol-induced depression on cell shortening and intracellular Ca(2+) was augmented in ADH group with maximal inhibitions of 66.8 and 69.6%, respectively. Interestingly, myocytes from CAT-ADH mice displayed normal ethanol response with maximal inhibitions of 46.0 and 47.2% for cell shortening and intracellular Ca(2+), respectively. CAT transgene lessened ethanol-induced inhibition on cell shortening (maximal inhibition of 30.3%) but not intracellular Ca(2+). ADH amplified ethanol-induced reactive oxygen species generation, which was nullified by the CAT transgene. Western blot analysis showed that ethanol reduced ERK phosphorylation and enhanced JNK phosphorylation without affecting p38 phosphorylation. The ethanol-induced changes in phosphorylation of ERK and JNK were amplified by ADH. CAT transgene itself did not affect ethanol-induced response in ERK and JNK phosphorylation, but it cancelled ADH-induced effects. These data suggest that antioxidant CAT may effectively antagonize ADH-induced enhanced cardiac depression in response to ethanol.
 ...
PMID:Cardiac overexpression of catalase antagonizes ADH-associated contractile depression and stress signaling after acute ethanol exposure in murine myocytes. 1610 28

Anisomycin is both a well-established protein synthesis inhibitor and a potent activator of the p38/JNK MAPK pathway. It has been used to block the late phase of long-term potentiation (LTP) and long-term depression (LTD) in hippocampus. In this study, we have found that anisomycin produces a time-dependent decline in the magnitude of the field EPSP (fEPSP) in acute brain slices of mouse primary visual cortex. This anisomycin-mediated fEPSP depression occludes NMDA receptor-dependent LTD induced by low-frequency stimulation (LFS). In contrast, two other protein synthesis inhibitors, emetine and cycloheximide, have no effect either on baseline synaptic transmission or on LTD. Moreover, the decline of the fEPSP caused by anisomycin can be rescued by the application of the p38 inhibitor SB203580 but not by the JNK inhibitor SP600125. These results indicate that activation of p38 MAPK by anisomycin induces LTD and subsequently occludes electrically induced LTD. Also, the occlusion of LFS-LTD by anisomycin suggests that common mechanisms may be shared between the two forms of synaptic depression. Consistent with this view, bath application of a membrane permeant peptide derived from the carboxyl tail of GluR2 subunit of AMPA receptor, which specifically blocks regulated AMPA receptor endocytosis, thereby preventing the expression of LFS-induced LTD, significantly reduced the anisomycin-induced decline of the fEPSP. In conclusion, our results indicate that anisomycin produces long-lasting depression of AMPA receptor-mediated synaptic transmission by activating p38 MAPK-mediated endocytosis of APMA receptors in mouse primary visual cortex.
 ...
PMID:Anisomycin activates p38 MAP kinase to induce LTD in mouse primary visual cortex. 1658 Oct 40

The formation of enduring internal representation of sensory information demands, in many cases, convergence in time and space of two different stimuli. The first conveys the sensory input, mediated via fast neurotransmission. The second conveys the meaning of the input, hypothesized to be mediated via slow neurotransmission. We tested the biochemical conditions and feasibility for fast (NMDA) and slow (dopamine) neurotransmission to converge on the Mitogen Activated Protein Kinase signaling pathways, crucial in several forms of synaptic plasticity, and recorded its effects upon synaptic transmission. We detected differing kinetics of ERK2 activation and synaptic strength changes in the CA1 for low and high doses of neurotransmitters in hippocampal slices. Moreover, when weak fast and slow inputs are given together, they converge on ERK2, but not on p38 or JNK, and induce strong short-term synaptic depression. Surprisingly, pharmacological analysis revealed that a probable site of such convergence is the NMDA receptor itself, suggesting it serves as a detector and integrator of fast and slow neurotransmission in the mature mammalian brain, as revealed by ERK2 activation and synaptic function.
 ...
PMID:NMDA and dopamine converge on the NMDA-receptor to induce ERK activation and synaptic depression in mature hippocampus. 1720 42

In Alzheimer's disease there is an increased production of the toxic beta-amyloid peptides (Abeta), especially the longer forms such as Abeta(1-42). Using the patch-clamp technique we have studied the contribution of early pro-inflammatory processes to the acute effects of 1 microM Abeta(1-42) on the parallel fiber EPSC (PF-EPSC) of Purkinje cells in cerebellar slices. Abeta(1-42) induces a decrease in the PF-EPSC amplitude. This decrease is accompanied by a decrease in the frequency and amplitude of the miniature EPSCs, suggesting that Abeta acts at both pre- and post-synaptic sites. In the presence of L-NAME, a nitric oxide synthase inhibitor, the effects of Abeta were partially blocked. The frequency of mEPSCs was unchanged while Abeta still reduced the mEPSCs amplitude. The anti-inflammatory agent flurbiprofen blocked the depressant action of Abeta on the mEPSCs amplitude but not its effect on mEPSCs frequency. Both a p38 inhibitor (SB203580) and a JNK inhibitor (SP600125) reverse the effects of Abeta as an increase in the mEPSCs frequency and amplitude was observed. This study provides evidence that the Abeta-induced depression of the PF-EPSCs was mediated via an activation of JNK and p38 and by the action of NO and raises the possibility of the involvement of an early pro-inflammatory process.
 ...
PMID:Beta-amyloid(1-42) induces a reduction in the parallel fiber responses of Purkinje cells: possible involvement of pro-inflammatory processes. 1759 99

Mitogen-activated protein kinases (MAPKs) are serine/threonine kinases that play an instrumental role in signal transduction from the cell surface to the nucleus. These enzymes are major intracellular mediators of developmental events and recently have been shown to control also synaptic plasticity processes [Sweatt, J.D., 2004. Mitogen-activated protein kinases in synaptic plasticity and memory. Curr. Opin. Neurobiol. 14, 311-317; Thomas, G.M., Huganir, R.L., 2004. MAPK cascade signalling and synaptic plasticity. Nat. Rev. Neurosci. 5, 173-183]. Mammalian members of this family are extracellular signal-regulated kinases 1/2 (ERK 1/2), c-Jun amino-terminal kinases or stress-activated protein kinases (JNK/SAPKs) and p38 kinases (p38(MAPK)). At the level of the visual system, it has been demonstrated that the ERK pathway regulates developmental plastic processes at both retino-thalamic and thalamo-cortical level and that p38(MAPK) controls a peculiar form of long-term depression in the visual cortex [Di Cristo, G., Berardi, N., Cancedda, L., Pizzorusso, T., Putignano, E., Ratto, G.M., Maffei, L., 2001. Requirement of ERK activation for visual cortical plasticity. Science 292, 2337-2340; Naska, S., Cenni, M.C., Menna, E., Maffei, L., 2004. ERK signaling is required for eye-specific retino-geniculate segregation. Development 131, 3559-3570; Xiong, W., Kojic, L.Z., Zhang, L., Prasad, S.S., Douglas, R., Wang, Y., Cynader, M.S., 2006. Anisomycin activates p38 MAP kinase to induce LTD in mouse primary visual cortex. Brain Res. 1085, 68-76]. Here, as a first approach to gain more insight on the role of two MAPKs - ERK1/2 and p38(MAPK) - in visual system maturation, we characterized by western blot the regulation of their phosphorylation/activation in rat retina, superior colliculus and visual cortex, during postnatal development from birth to adult age. Our main results show that: (i) in the retina p38(MAPK) activation peaks at P4, and then, from P15 to P45, both ERK1/2 and p38(MAPK) phosphorylation increases; (ii) in the superior colliculus phosphorylation of both MAPKs increases between P4 and P15; (iii) in the visual cortex ERK1/2 phosphorylation increases from P15 to P45, while phosphorylation of p38(MAPK) increases starting from P4. The present data demonstrate a distinct regulation of the activation of ERK1/2 and p38(MAPK) in the three visual areas analyzed which occurs in temporal correlation with critical events for visual system maturation. These results suggest an important role for ERK1/2 and p38(MAPK) in the postnatal development of the rat visual system.
 ...
PMID:The activation of ERK1/2 and p38 mitogen-activated protein kinases is dynamically regulated in the developing rat visual system. 1828 Jun 91

The aim of the present study was to investigate effects of some classical and new antidepressants on functional activity of the glucocorticoid receceptor (GR) induced by low corticosterone concentration in mouse fibroblast cells stably transfected with mouse mammary tumor virus-chloramphenicol acetyltransferase plasmid (LMCAT cells). We found that the transcriptional activity of GR stimulated by 50 nM corticosterone was strongly attenuated by imipramine, desipramine, fluoxetine and tianeptine in a concentration-dependent way, whereas reboxetine had only a weak effect and venlafaxine was inactive. Further study revealed that the inhibitor of c-Jun N-terminal kinase - mitogen-activated protein kinase (JNK-MAPK), SP600125 (0.1 microM), reversed the imipramine-induced suppression of GR function, whereas the inhibitor of extracellular signal-regulated kinase (ERK)-MAPK, PD 98059 (15 microM), potentiated the antidepressant action. No effect of selective inhibitors of p38-MAPK, phosphatidylinositol 3-kinase (PI3-K)/Akt, and glycogen synthase kinase (GSK-3) on the imipramine-induced inhibition of GR function was detected. These data indicate that the functional activity of GR evoked by low corticosterone concentration in LMCAT cells is efficiently inhibited by tricyclic antidepressants. Moreover, it was found that JNK- and ERK-MAPK were oppositely involved in the regulation of the imipramine-induced inhibition of the GR functional activity. Thus, the present study supports the notion that the interaction of antidepressants with GR may play a role in attenuating pathological hyperactivity of HPA axis in depression.
 ...
PMID:Effect of some antidepressants on the low corticosterone concentration-induced gene transcription in LMCAT fibroblast cells. 1844 95

Oxidative stress and endoplasmic reticulum (ER) stress have been implicated in cardiovascular diseases although the interplay between the two is not clear. This study was designed to examine the influence of oxidative stress through glutathione depletion on myocardial ER stress and contractile function in the absence or presence of the heavy metal scavenger antioxidant metallothionein (MT). FVB and MT overexpression transgenic mice received the GSH synthase inhibitor buthionine sulfoximine (BSO, 30 mM) in drinking water for 2 weeks. Oxidative stress, ER stress, apoptosis, cardiac function and ultrastructure were assessed using GSH/GSSG assay, reactive oxygen species (ROS), immunoblotting, caspase-3 activity, Langendorff perfused heart function (LVDP and +/-dP/dt), and transmission electron microscopy. BSO led to a robust decrease in the GSH/GSSG ratio and increased ROS production, consolidating oxidative stress. Cardiac function and ultrastructure were compromised following BSO treatment, the effect of which was obliterated by MT. BSO promoted overt ER stress as evidenced by upregulated BiP, calregulin, phospho-IRE1 alpha and phospho-eIF2 alpha without affecting total IRE1 alpha and eIF2 alpha. BSO treatment led to apoptosis manifested as elevated expression of CHOP/GADD153, caspase-12 and Bax as well as caspase-3 activity, reduced Bcl-2 expression and JNK phosphorylation, all of which was ablated by MT. Moreover, both antioxidant N-acetylcysteine and the ER stress inhibitor tauroursodeoxycholic acid reversed the oxidative stress inducer menadione-elicited depression in cardiomyocyte contractile function. Taken together, these data suggested that ER stress occurs likely downstream of oxidative stress en route to cardiac dysfunction.
 ...
PMID:Metallothionein alleviates oxidative stress-induced endoplasmic reticulum stress and myocardial dysfunction. 1934 29

Much research has indicated that the mitogen-activated protein kinase (MAPK)-cAMP response element-binding protein (CREB) signal transduction pathway is involved in the pathophysiological mechanism of depression. But as to the question of which MAPKs are more relevant to stress effects, there is no definite answer. In the present study, 32 male Sprague-Dawley rats were divided into chronic unpredictable stress (CUS) and control groups, with 16 rats in each group. The CUS rats were exposed to 21-day chronic unpredictable stressors, and the controls were stress-free. After stress, 16 rats (8 in each group) were tested for spatial memory using Morris Water Maze, and 16 rats (8 from each group) were decapitated for detection of the three most extensively studied subgroups of MAPKs, ERK1/2, JNK and P38, and CREB in the hippocampus. The results showed that there was no statistical difference in the body weight between the two groups. The CUS rats showed impaired spatial memory in MWM. Western blot of hippocampus showed that CUS significantly decreased pCREB and pJNK levels, but there was no statistical difference between two groups in CREB, ERK1/2, pERK1/2, P38, pP38 and JNK levels. Immunohistochemistry showed that the reduced pCREB occurred in the dentate gyrus, not in the hippocampus proper. In conclusion, this study highlights that the JNK-CREB pathway, not the P38-CREB or ERK1/2-CREB pathway, in the hippocampus played an important role in the 21-day-CUS, and that the impaired spatial memory acquisition in the CUS rats can be restored to the level comparable to the pre-stressed state.
 ...
PMID:Differential expression of mitogen-activated protein kinase signaling pathway in the hippocampus of rats exposed to chronic unpredictable stress. 1957 50


1 2 3 4 5 6 Next >>