UMLS:C0036341 - FACTA Search

Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036341 (schizophrenia)
60,220 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Homocysteine is increased during pathological conditions, endangering vascular and cognitive functions, and elevated homocysteine during pregnancy may be correlated with an increased incidence of schizophrenia in the offspring. This study showed that millimolar homocysteine concentrations in saline medium cause phosphorylation of extracellular-signal regulated kinases 1 and 2 (ERK(1/2)) in cerebellar granule neurons, inhibitable by metabotropic but not ionotropic glutamate receptor antagonists. These findings are analogous to observations by Zieminska et al. (2003), that similar concentrations cause neuronal death. However, these concentrations are much higher than those occurring clinically during hyperhomocysteinemia. It is therefore important that a approximately 10-fold increase in potency occurred in the presence of the glutamate precursor glutamine, when ERK(1/2) phosphorylation became inhibitable by NMDA or non-NMDA antagonists and dependent upon epidermal growth factor (EGF) receptor transactivation. However, glutamate release to the medium was reduced, suggesting that reversal of the cystine/glutamate antiporter, system X(c)(-) could be involved in potentiation of the response by causing a localized release of initially accumulated homocysteine. In agreement with this hypothesis further enhancement of ERK(1/2) phosphorylation occurred in the additional presence of cystine. Pharmacological inhibition of system X(c)(-) prevented the effect of micromolar homocysteine concentrations, and U0126-mediated inhibition of ERK(1/2) phosphorylation enhanced homocysteine-induced death. In conclusion, homocysteine interacts with system X(c)(-) like quisqualate (Venkatraman et al. 1994), by "self-sensitization" with initial accumulation and subsequent release in exchange with cystine and/or glutamate, establishing high local homocysteine concentrations, which activate adjacent ionotropic glutamate receptors and cause neurotoxicity.
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PMID:Potent homocysteine-induced ERK phosphorylation in cultured neurons depends on self-sensitization via system Xc(-). 1985 60

Schizophrenia is a common psychiatric disorder with a complex genetic aetiology. Evidence shows that the oligodendrocyte and myelin-related genes including ERBB3 are closely related to schizophrenia. Two recent studies (Kanazawa et al. (Am J Med Genet B Neuropsychiatr Genet 2007;144:113)) and Watanabe et al. (Neurosci Res 2007;57:574) reported there was no association between ERBB3 and schizophrenia in Japanese population. We investigated the ERBB3 gene given the putative functional nature of the gene and population heterogeneity between Asian and Caucasian. Scottish case and control samples were sequenced with four SNPs (rs705708 at intron 15, rs2271189, rs773123, rs2271188 at exon 27). We detected rs773123, which is a nonsynonymous Ser/Cys polymorphism located seven bases downstream of rs2271189, with P=0.034. The subgroups of male patients and patients with age at onset <45 showed evidence of significant association with P values of 0.0046 and 0.0055, respectively. To our knowledge, this is the first association study between ERBB3 and schizophrenia in the Caucasian population. Further investigation with large sample size should be helpful to clarify the nature of the gene.
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PMID:Case-control study of association between the functional candidate gene ERBB3 and schizophrenia in Caucasian population. 1999 12

Based on NMDA hypofunction hypothesis for negative symptoms and cognitive deficits in schizophrenia, MK-801-induced animal models of schizophrenia may help us understand the different effects between typical and atypical antipsychotics. On the other hand, the mitogen-activated protein kinase (MAPK) signaling pathways may participate in antipsychotic actions. The aim of this study was to investigate the effects of aripiprazole on MK-801-induced prepulse inhibition (PPI) disruption and MAPK phosphorylation in mice. To clarify the effects of aripiprazole on MK-801-induced PPI disruption, we measured PPI of 51 ddY male mice after aripiprazole was administered 15 min prior to the injection of MK-801, and measured activation of cytosol and nuclear MAPK phosphorylation by western blotting. Aripiprazole (4.0 mg/kg) significantly reversed the MK-801 (0.15 mg/kg)-induced PPI deficits. Pretreatment of aripiprazole (40 mg/kg) had a tendency to suppress MK-801 (1.0 mg/kg)-induced pMEK/MEK (Ser218/222) activation. In addition, aripiprazole treatment showed a significant decrease of pERK/ERK. Our data suggested that aripiprazole may reverse MK-801-induced PPI deficits through regulation of MAPK phosphorylation in the same way as the atypical antipsychotic drug, clozapine.
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PMID:Effects of aripiprazole on MK-801-induced prepulse inhibition deficits and mitogen-activated protein kinase signal transduction pathway. 2008 64

Animals with the neonatal ventral hippocampal lesion (NVHL) demonstrate altered responsiveness to stress and various drugs reminiscent of that in schizophrenia. Post-pubertal onset of abnormalities suggests the possibility of sex differences in NVHL effects that may model sex differences in schizophrenia. Here we demonstrate that novelty- and MK-801-induced hyperactivity is evident in both male and female NVHL rats, whereas only NVHL males were hyperactive in response to apomorphine. Next, we examined the sex- and NVHL-dependent differences in the activity of the ERK and Akt pathways. The basal activity of both pathways was higher in females than in males. NVHL reduces the level of phosphorylation of ERK1/2, Akt, and GSK-3 in both sexes, although males show more consistent down-regulation. Females had higher levels of G-protein-coupled kinases [G-protein-coupled receptor kinase (GRK)] 3 and 5, whereas the concentrations of other GRKs and arrestins were the same. In the nucleus accumbens, the concentration of GRK5 in females was elevated by NVHL to the male level. The data demonstrate profound sex differences in the expression and activity of signalling molecules that may underlie differential susceptibility to schizophrenia.
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PMID:Sex differences in the activity of signalling pathways and expression of G-protein-coupled receptor kinases in the neonatal ventral hippocampal lesion model of schizophrenia. 2015 34

Galantamine, a drug used to treat Alzheimer's disease, inhibits acetylcholinesterase (AChE) and allosterically modulates nicotinic acetylcholine receptors (nAChRs) resulting in stimulation of catecholamine neurotransmission. In this study, we investigated whether galantamine exerts cognitive-improving effects through the allosteric modulation of nAChRs in an animal model of methamphetamine (Meth) psychosis. The mice treated with Meth (1 mg/kg.d) for 7 d showed memory impairment in a novel object recognition test. Galantamine (3 mg/kg) ameliorated the memory impairment, and it increased the extracellular dopamine release in the prefrontal cortex (PFC) of Meth-treated mice. Donepezil, an AChE inhibitor (1 mg/kg) increased the extracellular ACh release in the PFC, whereas it had no effect on the memory impairment in Meth-treated mice. The nAChR antagonist, mecamylamine, and dopamine D1 receptor antagonist, SCH 23390, blocked the ameliorating effect of galantamine on Meth-induced memory impairment, whereas the muscarinic AChR antagonist, scopolamine, had no effect. The effects of galantamine on extracellular dopamine release were also antagonized by mecamylamine. Galantamine attenuated the defect of the novelty-induced activation of extracellular signal-regulated kinase 1/2 (ERK1/2). The ameliorating effect of galantamine on recognition memory in Meth-treated mice was negated by microinjection of an ERK inhibitor, PD98059, into the PFC. These results suggest that the ameliorating effect of galantamine on Meth-induced memory impairment is associated with indirect activation of dopamine D1 receptor-ERK1/2 following augmentation with dopaminergic neurotransmission in the PFC through the allosteric activation of nAChRs. Galantamine could be a useful therapeutic agent for treating cognitive deficits in schizophrenia/Meth psychosis, as well as Alzheimer's disease.
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PMID:Galantamine ameliorates the impairment of recognition memory in mice repeatedly treated with methamphetamine: involvement of allosteric potentiation of nicotinic acetylcholine receptors and dopaminergic-ERK1/2 systems. 2021 55

Schizophrenia is a complex disorder that interferes with the function of several brain systems required for cognition and normal social behaviour. Although the most notable clinical aspects of the disease only become apparent during late adolescence or early adulthood, many lines of evidence suggest that schizophrenia is a neurodevelopmental disorder with a strong genetic component. Several independent studies have identified neuregulin 1 (NRG1) and its receptor ERBB4 as important risk genes for schizophrenia, although their precise role in the disease process remains unknown. Here we show that Nrg1 and ErbB4 signalling controls the development of inhibitory circuitries in the mammalian cerebral cortex by cell-autonomously regulating the connectivity of specific GABA (gamma-aminobutyric acid)-containing interneurons. In contrast to the prevalent view, which supports a role for these genes in the formation and function of excitatory synapses between pyramidal cells, we found that ErbB4 expression in the mouse neocortex and hippocampus is largely confined to certain classes of interneurons. In particular, ErbB4 is expressed by many parvalbumin-expressing chandelier and basket cells, where it localizes to axon terminals and postsynaptic densities receiving glutamatergic input. Gain- and loss-of-function experiments, both in vitro and in vivo, demonstrate that ErbB4 cell-autonomously promotes the formation of axo-axonic inhibitory synapses over pyramidal cells, and that this function is probably mediated by Nrg1. In addition, ErbB4 expression in GABA-containing interneurons regulates the formation of excitatory synapses onto the dendrites of these cells. By contrast, ErbB4 is dispensable for excitatory transmission between pyramidal neurons. Altogether, our results indicate that Nrg1 and ErbB4 signalling is required for the wiring of GABA-mediated circuits in the postnatal cortex, providing a new perspective to the involvement of these genes in the aetiology of schizophrenia.
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PMID:Control of cortical GABA circuitry development by Nrg1 and ErbB4 signalling. 2039 64

The Ras family GTPases (Ras, Rap1, and Rap2) and their downstream mitogen-activated protein kinases (ERK, JNK, and p38MAPK) and PI3K signaling cascades control various physiological processes. In neuronal cells, recent studies have shown that these parallel cascades signal distinct forms of AMPA-sensitive glutamate receptor trafficking during experience-dependent synaptic plasticity and adaptive behavior. Interestingly, both hypo- and hyperactivation of Ras/ Rap signaling impair the capacity of synaptic plasticity, underscoring the importance of a "happy-medium" dynamic regulation of the signaling. Moreover, accumulating reports have linked various genetic defects that either up- or down-regulate Ras/Rap signaling with several mental disorders associated with learning disability (e.g., Alzheimer's disease, Angelman syndrome, autism, cardio-facio-cutaneous syndrome, Coffin-Lowry syndrome, Costello syndrome, Cowden and Bannayan-Riley-Ruvalcaba syndromes, fragile X syndrome, neurofibromatosis type 1, Noonan syndrome, schizophrenia, tuberous sclerosis, and X-linked mental retardation), highlighting the necessity of happy-medium dynamic regulation of Ras/Rap signaling in learning behavior. Thus, the recent advances in understanding of neuronal Ras/Rap signaling provide a useful guide for developing novel treatments for mental diseases.
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PMID:Ras and Rap signaling in synaptic plasticity and mental disorders. 2043 Oct 46

Schizophrenia is a psychiatric disorder with onset in late adolescence and unclear etiology characterized by both positive and negative symptoms, as well as cognitive deficits. To identify copy number variations (CNVs) that increase the risk of schizophrenia, we performed a whole-genome CNV analysis on a cohort of 977 schizophrenia cases and 2,000 healthy adults of European ancestry who were genotyped with 1.7 million probes. Positive findings were evaluated in an independent cohort of 758 schizophrenia cases and 1,485 controls. The Gene Ontology synaptic transmission family of genes was notably enriched for CNVs in the cases (P = 1.5 x 10(-7)). Among these, CACNA1B and DOC2A, both calcium-signaling genes responsible for neuronal excitation, were deleted in 16 cases and duplicated in 10 cases, respectively. In addition, RET and RIT2, both ras-related genes important for neural crest development, were significantly affected by CNVs. RET deletion was exclusive to seven cases, and RIT2 deletions were overrepresented common variant CNVs in the schizophrenia cases. Our results suggest that novel variations involving the processes of synaptic transmission contribute to the genetic susceptibility of schizophrenia.
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PMID:Strong synaptic transmission impact by copy number variations in schizophrenia. 2048 79

There is a relatively high genetic heritability of schizophrenia as shown by family, twin and adoption studies. A large number of hypotheses on the causes of schizophrenia occurred over time. In this review we focus on genetic findings related to potential alterations of intracellular Ca-homeostasis in association with schizophrenia. First, we provide evidence for the NMDA/glutamatergic theory of schizophrenia including calcium processes. We mainly focus on genes including: DAO (D-amino acid oxidase), DAOA (D-amino acid oxidase activator), DTNBP1 (Dysbindin 1, dystrobrevin-binding protein 1), NRG1 (Neuregulin 1), ERBB4 (v-erb-a erythroblastic leukemia viral oncogene homolog 4, avian), NOS1 (nitric oxide synthase 1, neuronal) and NRGN (Neurogranin). Furthermore, a gene coding for a calcium channel subunit (CACNA1C: calcium channel, voltage-dependent, L type, alpha 1C subunit) is discussed in the light of schizophrenia whereas genetic findings related to alterations in the intracellular Ca-homeostasis associated specifically with dopaminergic and serotonergic neurotransmission in schizophrenia are not herein closer reviewed. Taken together there is converging evidence for the contribution of genes potentially related to alterations in intracellular Ca-homeostasis to the risk of schizophrenia. Replications and functional studies will hopefully provide further insight into these genetic variants and the underlying processes.
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PMID:Genetic findings in schizophrenia patients related to alterations in the intracellular Ca-homeostasis. 2060 Apr 64

Cellular, animal and human studies support the involvement of aberrant NRG-ErbB signaling in the pathogenesis of schizophrenia. The aim of the present study was to examine whether genetic variation in the human ERBB4 gene is associated with susceptibility to schizophrenia. Two hundred and twenty-seven unrelated chronic inpatients with schizophrenia were enrolled in the study, and the genetic variation in the polymorphisms of the ERBB4 gene in the patients was compared with that of the control group, which consisted of 223 subjects free of psychiatric illness. The results showed that one coding-synonymous polymorphism (rs3748962, Val1065Val) was in genotypic (p=0.0027) and allelic (p=0.0007) association with schizophrenia. In comparison with subjects of the rs3748962-TT type, those of the rs3748962-CT and rs3748962-CC types were at 1.74- and 2.64-fold greater risk of schizophrenia (CT vs. TT: OR=1.71 (95% CI=1.15-2.53), p=0.0014; CC vs. TT: OR=2.64 (95% CI=1.37-5.23), p=0.0047), which supports the hypothesis of an additive model of transmission (p=0.0006). Furthermore, the frequency of haplotype ATC of rs3791709-rs2289086-rs3748962 was found to be significantly higher in the patients with schizophrenia than in the controls (case vs. control=36.0% vs. 24.4%, permutation p-value=0.0002). The findings support the involvement of the ERBB4 gene in schizophrenia in Han Chinese.
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PMID:Support for the involvement of the ERBB4 gene in schizophrenia: a genetic association analysis. 2060 May 94

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