Search

BackgroundNeurodevelopmental deficits resulting from prenatal stress are associated with neurological disorders that include deficits of social behavior, such as schizophrenia1 and autism2–7. Studies of human brain and animal models indicate that an epitranscriptomic process known as ‘RNA editing’ contributes to the pathophysiology of these disorders, which occur more frequently in males than in females8–20. RNA editing plays an important role in brain development through its modification of excitatory and inhibitory neurotransmission21.MethodsWe exposed pregnant mice to restraint stress three times daily during gestational weeks 2 and 3. We treated the adult male offspring with haloperidol (1mg/kg), clozapine (5mg/kg) or saline twice daily for 5 days. Subsequently we measured social interaction behavior (SI) and locomotor activity, followed by next-generation sequencing analyses of hippocampal RNA editing.ResultsMice exposed to PRS exhibited reduced SI, which correlated with hippocampal RNA editing of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunits GluA2, GluA3 and GluA4, the potassium channel Kv1.1, the calcium channel subunit Cav1.3, calcium-dependent secretion activator (CAPS-1) and the calcium-dependent cell adhesion protein, cadherin 22 (CDH22). Treatment with clozapine, but not haloperidol, normalized SI behavior, and selectively reduced the deficits in GluA2 RNA editing in PRS mice.ConclusionsRNA editing may contribute to impaired hippocampal function after exposure to PRS. The efficacy of clozapine in improving SI behavior may include indirect stimulation of GluA2 RNA editing in the hippocampus. Although these data are from male mice and not humans, the results suggest a new molecular pathway by which PRS leads to life-long impairments of hippocampal function.

Accumulating evidence indicates that the glutamate and monoamine systems contribute to the pathophysiology of major depressive disorder (MDD) and suicide. We have tested the expression of genes encoding glutamate transporters and monoaminergic proteins in the dorsolateral prefrontal cortex (DLPFC) of MDD subjects who died by suicide (MDD-S, n=51), MDD non-suicide subjects (MDD-NS, n=28), and non-psychiatric controls (CTRL, n=32). We analyzed glutamate transporters (EAAT1, EAAT2, VGLUT1, and VGLUT2) and monoaminergic genes (SERT, NET, DAT, PMAT, VMAT, TPH1 and TPH2). Females but not males with MDD showed higher expression of all glutamate transporters relative to CTRLs (P

Accumulating data indicate that the glutamate system is disrupted in major depressive disorder (MDD), and recent clinical research suggests that ketamine, an antagonist of the N-methyl-d-aspartate (NMDA) glutamate receptor (GluR), has rapid antidepressant efficacy. Here we report findings from gene expression studies of a large cohort of postmortem subjects, including subjects with MDD and controls. Our data reveal higher expression levels of the majority of glutamatergic genes tested in the dorsolateral prefrontal cortex (DLPFC) in MDD (F21,59=2.32, P=0.006). Posthoc data indicate that these gene expression differences occurred mostly in the female subjects. Higher expression levels of GRIN1, GRIN2A-D, GRIA2-4, GRIK1-2, GRM1, GRM4, GRM5 and GRM7 were detected in the female patients with MDD. In contrast, GRM5 expression was lower in male MDD patients relative to male controls. When MDD suicides were compared with MDD non-suicides, GRIN2B, GRIK3 and GRM2 were expressed at higher levels in the suicides. Higher expression levels were detected for several additional genes, but these were not statistically significant after correction for multiple comparisons. In summary, our analyses indicate a generalized disruption of the regulation of the GluRs in the DLPFC of females with MDD, with more specific GluR alterations in the suicides and in the male groups. These data reveal further evidence that, in addition to the NMDA receptor, the AMPA, kainate and the metabotropic GluRs may be targets for the development of rapidly acting antidepressant drugs.

BACKGROUND: Tumor necrosis factor (TNF)-alpha inhibitors and other biologic response modifiers (BRMs) are frequently used to treat a variety of inflammatory diseases. Use of these agents may increase risk of serious infections, malignancies, and other complications such as worsening symptoms of heart failure or demyelinating disease. Because of these risks, a baseline assessment and routine monitoring have been recommended, but standardized guidelines for monitoring have yet to be established. OBJECTIVE: To measure the compliance with the recommended safety monitoring in the Clinical Care Guidelines for BRMs at the University of Illinois Hospitals and Health Sciences System (UI Health). METHODS: The Clinical Care Guidelines for BRMs was developed by a committee of pharmacists, nurses, and physicians based on an assessment of published literature and medication labeling. The guidelines included recommendations for safety monitoring prior to BRM therapy, such as the tuberculosis (TB) test, Hepatitis B surface Antigen (HBsAg) test, liver function test (LFT), complete blood count (CBC), up-to-date vaccinations, risk assessment for cancer, pregnancy testing, monitoring for contraindications with concomitant medications, concomitant disease state risk assessment, and patient education. The guidelines were introduced to UI Health in February 2012 by a systemwide email and by in-services given by the health system’s Specialty Pharmacy Service. In-services were given in the clinics known to generate large numbers of BRM orders (e.g., gastroenterology and rheumatology) and at the outpatient center for infused therapies. The purpose of the in-services was to introduce providers to the guidelines and encourage their compliance. To ensure that guideline requirements were met when BRMs were ordered, a process was established to identify BRM orders, assess the orders for compliance with 4 of the safety monitoring tests from the guidelines (TB, HBsAg, LFT, and CBC), and make interventions. When necessary, Specialty Pharmacy Services coordinated with the pharmacists and other providers in the clinic to order lab tests and ensure they were completed prior to the start of therapy. Feedback was provided during the study to proactively improve compliance with the guidelines. After completion of the study, a report containing outpatient prescription orders for BRMs (abatacept, adalimumab, certolizumab, etanercept, golimumab, infliximab, and tocilizumab) from August 2011 through July 2012 was generated from the electronic medical record. Retrospective analyses of completion of safety monitoring were conducted for patients administered BRM treatment. Completion rates were compared before and after implementation of guidelines in February 2012. Completion was considered to have occurred when all 4 safety monitoring tests had been conducted —TB (unless known to be positive from a previous test), HBsAg, LFT, and CBC. Completion data from August 2011 through January 2012 were before the guidelines were implemented, and data from February 2012 through July 2012 were after the guidelines. Chi square analyses were performed on completion frequencies in the patients before and after the guidelines were implemented. RESULTS: Of the 320 unique patient BRM orders evaluated in this study, 195 (61%) were generated in the Rheumatology clinic, 99 (31%) in the Gastroenterology clinic, 21 (6.5%) in the Dermatology clinic, and 5 (1.5%) in the Transplant clinic. Before the guidelines were implemented, 54 ( 31%) of 173 patient orders complied with the safety monitoring by having all 4 clinical tests performed at the appropriate time points. After guideline implementation, 88 (60%) of 147 patient orders were compliant and had all 4 clinical tests conducted, which represents a statistically significant improvement in the rate of compliance (Pearson chi square = 26.43

Background Impairment of glutamate neurons that relay sensory and cognitive information from the medial dorsal thalamus to the dorsolateral prefrontal cortex and other cortical regions may contribute to the pathophysiology of schizophrenia. In this study, we have assessed the cell-specific expression of glutamatergic transcripts in the medial dorsal thalamus. Methods We used laser capture microdissection to harvest two populations of medial dorsal thalamic cells, one enriched with glutamatergic relay neurons and the other with gamma-aminobutyric acidergic neurons and astroglia, from postmortem brains of subjects with schizophrenia ( n = 14) and a comparison group ( n = 20). Quantitative polymerase chain reaction of extracted RNA was used to assay gene expression in the different cell populations. Results The transcripts encoding the ionotropic glutamate receptor subunits NR2D, GluR3, GluR6, GluR7, and the intracellular proteins GRIP1 and SynGAP1 were significantly decreased in relay neurons but not in the mixed glial and interneuron population in schizophrenia. Conclusions Our data suggest that reduced ionotropic glutamatergic expression occurs selectively in neurons, which give rise to the cortical projections of the medial dorsal thalamus in schizophrenia, rather than in thalamic cells that function locally. Our findings indicate that glutamatergic innervation is dysfunctional in the circuitry between the medial dorsal thalamus and cortex.

Schizophrenia is a severe psychiatric disorder which influences around 1 % of the worldwide population. Differences between male and female patients with schizophrenia have been noted. There is an earlier age of onset in males compared with females with this diagnosis, and in addition, there are differences in symptom profiles between the sexes. The underlying molecular mechanism of sex difference remains unclear. Here we present a comprehensive analysis to reveal the sex differences in gene expression in schizophrenia with stringent statistics criteria. We compiled a data set consisting of 89 male controls, 90 male schizophrenia patients, 35 female controls and 32 female schizophrenia patients from six independent studies of the prefrontal cortex (PFC) in postmortem brain. When we tested for a sex by diagnosis interaction on gene expression, 23 genes were up-regulated and 23 genes were down-regulated in the male group (q-value

article GABAergic dysfunction has been strongly implicated in the pathophysiology of schizophrenia. In this study, we analyzed the expression levels of several GABAergic genes in the anterior cingulate cortex (ACC) of postmortem subjects with schizophrenia (n = 21) and a comparison group of individuals without a history of psychiatric ill- ness (n = 18). Our analyses revealed a significant sex by diagnosis effect, along with significant differences in GABAergic gene expression based on medication status. Analyses revealed that in male groups, the expression of GABAergic genes was generally lower in schizophrenia cases compared to the controls, with significantly lower expression levels of GABA-Aα5, GABA-Aβ1, and GABA-Ae. In females, the expression of GABAergic genes was higher in the schizophrenia cases, with significantly higher expression of the GABA-Aβ1 and GAD67 genes. Analysis of the effect of medication in the schizophrenia subjects revealed significantly higher expression ofGABA-Aα1-3,GABA-Aβ2,GABA-Aγ2,andGAD67inthemedicatedgroupcomparedtotheunmedicatedgroup. These data show that sex differences in the expression of GABAergic genes occur in the ACC in schizophrenia. Therefore, our data support previous findings of GABAergic dysfunction in schizophrenia and emphasize the importance of considering sex in analyses of the pathophysiology of schizophrenia. Sex differences in the GABAergic regulation of ACC function may contribute to the differences observed in the symptoms of male and female patients with schizophrenia. In addition, our findings indicate that antipsychotic medications may alter GABAergic signaling in the ACC, supporting the potential of GABAergic targets for the development of novel antipsychotic medication.

Epidemiological research suggests that both an individual's genes and the environment underlie the pathophysiology of schizophrenia. Molecular mechanisms mediating the interplay between genes and the environment are likely to have a significant role in the onset of the disorder. Recent work indicates that epigenetic mechanisms, or the chemical markings of the DNA and the surrounding histone proteins, remain labile through the lifespan and can be altered by environmental factors. Thus, epigenetic mechanisms are an attractive molecular hypothesis for environmental contributions to schizophrenia. In this review, we first present an overview of schizophrenia and discuss the role of nature versus nurture in its pathology, where 'nature' is considered to be inherited or genetic vulnerability to schizophrenia, and 'nurture' is proposed to exert its effects through epigenetic mechanisms. Second, we define DNA methylation and discuss the evidence for its role in schizophrenia. Third, we define posttranslational histone modifications and discuss their place in schizophrenia. This research is likely to lead to the development of epigenetic therapy, which holds the promise of alleviating cognitive deficits associated with schizophrenia.

Schizophrenia is a debilitating lifelong disorder affecting up to 1% of the population worldwide, producing significant financial and emotional hardship for patients and their families. As yet, the causes of schizophrenia and the mechanism of action of antipsychotic drugs are unknown, and many patients do not respond well to currently available medications. Attempts to find risk factors for the disorder using epidemiological methods have shown that schizophrenia is highly heritable, and path analyses predict that the disorder is caused by several genes in combination with nongenetic factors. Therefore, intensive research efforts have been made to identify genes creating vulnerability to schizophrenia and also genes predicting response to treatment. Interactions of the glutamatergic system with dopaminergic and serotonergic circuitry are crucial for normal brain function, and their disruption may be a mechanism by which the pathophysiology of schizophrenia is manifest. Genes within the glutamatergic system are therefore strong candidates for investigation, and these include the glutamate receptor genes in addition to genes encoding neuregulin, dysbindin, D-amino acid oxidase and G72/G30. These genetic studies could eventually reveal new targets for antipsychotic drug treatment, which currently focuses on inhibition of the dopaminergic system. However, a recent breakthrough indicates clinical efficacy of a drug stimulating the metabotropic glutamate receptor II, LY2140023, which has improved efficacy for negative and cognitive symptoms of schizophrenia. Studies of larger patient samples are required to consolidate these data. Further investigation of glutamatergic targets is likely to reinvigorate antipsychotic drug development.

Catechol-o-methyltransferase (COMT) and proline dehydrogenase (PRODH) may both be susceptibility genes for schizophrenia. As part of the evaluation of their roles in psychosis, we used reverse transcription-polymerase chain reaction to measure COMT and PRODH mRNAs in the dorsolateral prefrontal cortex in schizo- phrenia, bipolar disorder, major depression, and normal controls (n 15 subjects in each group). We also genotyped two common COMT polymorphisms (-287A/G and 158Val/ Met) which might affect its expression. Neither COMT nor PRODH mRNA abundance differed between diagnostic groups, nor when controls were compared with all psychotic patients. COMT mRNA levels were unrelated to COMT genotypes. We conclude that any involvement of COMT and PRODH genes in schizophrenia is not accompanied by significant alterations in their overall mRNA expression, at least in dorsolateral pre- frontal cortex. As COMT and PRODH are both located on chromosome 22q11, the results also argue against the hypothesis that schizophrenia is associated with a decrease in expression of all 22q11 genes, as had been suggested by the high prevalence of psychosis in people with hemizygous 22q11 deletions. Synapse 51:112-118, 2004. © 2003 Wiley-Liss, Inc.

5-HT(2C) receptor (5HT(2C)R, serotonin-2C) RNA undergoes editing to produce several receptor variants, some with pharmacological differences. This investigation comprised two parts: the characterisation of 5-HT(2C)R RNA editing in a larger human control sample than previously examined, and a comparative study in subjects with schizophrenia. Secondary structure analysis of the putative edited region of the human 5-HT(2C)R gene predicted the existence of a double stranded (ds) RNA loop, essential for RNA editing in this receptor. RNA was then extracted from frontal cortex of five controls and five subjects with schizophrenia. RT-PCR products of the edited region were cloned and sequenced (n = 100). Reduced RNA editing, increased expression of the unedited 5-HT(2C-INI) isoform in schizophrenia (P = 0.001) and decreased expression of the 5-HT(2C-VSV) and 5-HT(2C-VNV) isoforms were detected in the schizophrenia group. In addition, two novel mRNA edited variants were identified: 5-HT(2C-MNI) and 5-HT(2C-VDI). Screening of the 5-HT(2C)R gene did not reveal any mutations likely to disrupt the dsRNA loop, suggesting that the reduced RNA editing in schizophrenia may instead be caused by altered activity of the editing enzyme(s). Since the unedited 5-HT(2C-INI) is more efficiently coupled to G proteins than the other isoforms, its increased expression in schizophrenia may lead to enhanced 5-HT(2C)R-mediated effects. The results also illustrate that potentially important receptor alterations may occur in schizophrenia which are not detectable merely in terms of receptor abundance.