Lower number of cerebellar Purkinje neurons in psychosis is associated with reduced reelin expression.

Reelin is an extracellular matrix protein synthesized in cerebellar granule cells that plays an important role in Purkinje cell positioning during cerebellar development and in modulating adult synaptic function. In the cerebellum of schizophrenia (SZ) and bipolar (BP) disorder patients, there is a marked decrease ( approximately 50%) of reelin expression. In this study we measured Purkinje neuron density in the Purkinje cell layer of cerebella of 13 SZ and 17 BP disorder patients from the McLean 66 Cohort Collection, Harvard Brain Tissue Resource Center. The mean number of Purkinje neurons (linear density, neurons per millimeter) was 20% lower in SZ and BP disorder patients compared with nonpsychiatric subjects (NPS; n = 24). This decrease of Purkinje neuron linear density was unrelated to postmortem interval, pH, drugs of abuse, or to the presence, dose, or duration of antipsychotic medications. A comparative study in the cerebella of heterozygous reeler mice (HRM), in which reelin expression is down-regulated by approximately 50%, showed a significant loss in the number of Purkinje cells in HRM (10-15%) compared with age-matched (3-9 months) wild-type mice. This finding suggests that lack of reelin impairs GABAergic Purkinje neuron expression and/or positioning during cerebellar development.

Clinical utility of whole-genome DNA methylation profiling as a primary molecular diagnostic assay for central nervous system tumors-A prospective study and guidelines for clinical testing.

Background: Central nervous system (CNS) cancer is the 10th leading cause of cancer-associated deaths for adults, but the leading cause in pediatric patients and young adults. The variety and complexity of histologic subtypes can lead to diagnostic errors. DNA methylation is an epigenetic modification that provides a tumor type-specific signature that can be used for diagnosis. Methods: We performed a prospective study using DNA methylation analysis as a primary diagnostic method for 1921 brain tumors. All tumors received a pathology diagnosis and profiling by whole genome DNA methylation, followed by next-generation DNA and RNA sequencing. Results were stratified by concordance between DNA methylation and histopathology, establishing diagnostic utility. Results: Of the 1602 cases with a World Health Organization histologic diagnosis, DNA methylation identified a diagnostic mismatch in 225 cases (14%), 78 cases (5%) did not classify with any class, and in an additional 110 (7%) cases DNA methylation confirmed the diagnosis and provided prognostic information. Of 319 cases carrying 195 different descriptive histologic diagnoses, DNA methylation provided a definitive diagnosis in 273 (86%) cases, separated them into 55 methylation classes, and changed the grading in 58 (18%) cases. Conclusions: DNA methylation analysis is a robust method to diagnose primary CNS tumors, improving diagnostic accuracy, decreasing diagnostic errors and inconclusive diagnoses, and providing prognostic subclassification. This study provides a framework for inclusion of DNA methylation profiling as a primary molecular diagnostic test into professional guidelines for CNS tumors. The benefits include increased diagnostic accuracy, improved patient management, and refinements in clinical trial design.

Phase 0 Clinical Trial of Everolimus in Patients with Vestibular Schwannoma or Meningioma.

Inhibition of mTORC1 signaling has been shown to diminish growth of meningiomas and schwannomas in preclinical studies, and clinical data suggest that everolimus, an orally administered mTORC1 inhibitor, may slow tumor progression in a subset of patients with neurofibromatosis type 2 (NF2) with vestibular schwannoma. To assess the pharmacokinetics, pharmacodynamics, and potential mechanisms of treatment resistance, we performed a presurgical (phase 0) clinical trial of everolimus in patients undergoing elective surgery for vestibular schwannoma or meningiomas. Eligible patients with meningioma or vestibular schwannoma requiring tumor resection enrolled on study received everolimus 10 mg daily for 10 days immediately prior to surgery. Everolimus blood levels were determined immediately before and after surgery. Tumor samples were collected intraoperatively. Ten patients completed protocol therapy. Median pre- and postoperative blood levels of everolimus were found to be in a high therapeutic range (17.4 ng/mL and 9.4 ng/mL, respectively). Median tumor tissue drug concentration determined by mass spectrometry was 24.3 pg/mg (range, 9.2-169.2). We observed only partial inhibition of phospho-S6 in the treated tumors, indicating incomplete target inhibition compared with control tissues from untreated patients (P = 0.025). Everolimus led to incomplete inhibition of mTORC1 and downstream signaling. These data may explain the limited antitumor effect of everolimus observed in clinical studies for patients with NF2 and will inform the design of future preclinical and clinical studies targeting mTORC1 in meningiomas and schwannomas.

FOLLICLE-STIMULATING HORMONE-PRODUCING PITUITARY ADENOMA: A CASE REPORT AND REVIEW OF THE LITERATURE.

OBJECTIVE: To describe an unusual presentation of a follicle-stimulating hormone-secreting pituitary adenoma leading to ovarian hyperstimulation syndrome. We also discuss the pathophysiology and subsequent management of these tumors. METHODS: This is a case report and review of the literature. A 37-year-old female with menorrhagia was found to have bilateral multilocular adnexal cysts with concern for ovarian hyperstimulation syndrome. RESULTS: Labs revealed elevated follicle-stimulating hormone, and an eminent estradiol level. Pituitary magnetic resonance imaging revealed a macroadenoma with cavernous sinus invasion. The patient went on to have a successful transsphenoidal resection with normalization of hormones and subsequent resumption of menstrual cycles. CONCLUSION: With the help of this case report, we illustrate the pathogenesis of functioning gonadotroph adenomas as well as the management challenges associated with these tumors. Our case is unique in its presentation with severe hyperestrogenemia and cavernous sinus invasion pointing towards a clinically aggressive adenoma. It is important to increase awareness of these tumors to ensure timely and effective management of their complications.

Epigenetic mechanisms expressed in basal ganglia GABAergic neurons differentiate schizophrenia from bipolar disorder.

In the cerebral prefrontal cortex (PFC), DNA-methyltransferase 1 (DNMT1), the enzyme that catalyzes the methylation of cytosine at carbon atoms in position 5 in CpG dinucleotides, is expressed selectively in GABAergic neurons and is upregulated in layers I and II of schizophrenia (SZ) and bipolar disorder patients with psychosis (BDP). To replicate these earlier findings and to verify whether overexpression of DNMT1 and the consequent epigenetic decrease of reelin and glutamic acid decarboxylase (GAD) 67 mRNA expression also occur in GABAergic medium spiny neurons of the caudate nucleus (CN) and putamen (PT) of SZ and BDP, we studied the entire McLean 66 Cohort (Harvard Brain Tissue Resource Center, McLean Hospital, Belmont, MA) including SZ and BDP, which were matched with nonpsychiatric subjects. The data demonstrate that in GABAergic medium spiny neurons of CN and PT, unlike in GABAergic neurons of layer I and II PFC, the increased expression of DNMT1 and the decrease of reelin and GAD67 occur in SZ but not in BDP. This suggests that different epigenetic mechanisms must exist in the pathogenesis underlying SZ and BDP and implies that these disorders might involve two separate entities that are characterized by a well-defined neuropathology.

Optimization of DNA concentration to amplify short tandem repeats of human genomic DNA.

Analysis of the length polymorphisms of short tandem repeats (STR) loci in the human genome has become a standard approach for comparative genotyping in many areas including disease research and diagnostics, parentage assessment, investigations of human diversity, and forensic science. The purpose of this study is to optimize the DNA concentration in ng/10 µL for amplification of DNA markers. AmpFlSTR Identifiler Kit is used to amplify STR markers and capillary electrophoresis is used to analyze DNA profile of human the genome. Two sets of samples with following DNA concentration: 100 pg - 6 ng/25 µL were used for this study. There was no DNA profile detected in samples with concentrations 100 pg - 300 pg/ 25 µL (pictogram), while in some cases partial DNA profile was yielded. On the other hand samples with 0.4 ng - 4 ng/ 25 µL, yielded a full DNA profile. We were not able to obtain any profile using concentrations over 4 ng/ 25 µL. Improvements in detection limits/sensitivity at upper and lower DNA concentrations are of potential benefits to amplify STR of Human Genomic in order to obtain a full DNA profile. The optimal DNA concentrations which produced reliable and balanced peaks, no off scale peaks and full DNA profile for all loci were at range 0.4 ng - 3 ng/ 25 µL.

Selective α4ß2 nicotinic acetylcholine receptor agonists target epigenetic mechanisms in cortical GABAergic neurons.

Nicotine improves cognitive performance and attention in both experimental animals and in human subjects, including patients affected by neuropsychiatric disorders. However, the specific molecular mechanisms underlying nicotine-induced behavioral changes remain unclear. We have recently shown in mice that repeated injections of nicotine, which achieve plasma concentrations comparable to those reported in high cigarette smokers, result in an epigenetically induced increase of glutamic acid decarboxylase 67 (GAD(67)) expression. Here we explored the impact of synthetic α(4)ß(2) and α(7) nAChR agonists on GABAergic epigenetic parameters. Varenicline (VAR), a high-affinity partial agonist at α(4)ß(2) and a lower affinity full agonist at α(7) neuronal nAChR, injected in doses of 1-5 mg/kg/s.c. twice daily for 5 days, elicited a 30-40% decrease of cortical DNA methyltransferase (DNMT)1 mRNA and an increased expression of GAD(67) mRNA and protein. This upregulation of GAD(67) was abolished by the nAChR antagonist mecamylamine. Furthermore, the level of MeCP(2) binding to GAD(67) promoters was significantly reduced following VAR administration. This effect was abolished when VAR was administered with mecamylamine. Similar effects on cortical DNMT1 and GAD(67) expression were obtained after administration of A-85380, an agonist that binds to α(4)ß(2) but has negligible affinity for α(3)ß(4) or α(7) subtypes containing nAChR. In contrast, PNU-282987, an agonist of the homomeric α(7) nAChR, failed to decrease cortical DNMT1 mRNA or to induce GAD(67) expression. The present study suggests that the α(4)ß(2) nAChR agonists may be better suited to control the epigenetic alterations of GABAergic neurons in schizophrenia than the α(7) nAChR agonists.

The Decrease of n-3 Fatty Acid Energy Percentage in an Equicaloric Diet Fed to B6C3Fe Mice for Three Generations Elicits Obesity.

Feeding mice, over 3 generations, an equicaloric diet in which alpha-linolenic acid, the dietary precursor of n-3 polyunsaturated fatty acids, was substituted by linoleic acid, the dietary precursor of n-6 polyunsaturated fatty acids, significantly increased body weight throughout life when compared with standard diet-fed mice. Adipogenesis observed in the low n-3 fatty acid mice was accompanied by a 6-fold upregulation of stearyl-coenzyme A desaturase 1 (Scd1), whose activity is correlated to plasma triglyceride levels. In total liver lipid and phospholipid extracts, the sum of n-3 fatty acids and the individual longer carbon chain acids, eicosapentaenoic acid (20:5n3), docosapentaenoic acid (22:5n3), and docosahexaenoic acid (22:6n3) were significantly decreased whereas arachidonic acid (20:4n6) was significantly increased. In addition, low n-3 fatty acid-fed mice had liver steatosis, heart, and kidney hypertrophy. Hence, reducing dietary alpha-linolenic acid, from 1.02 energy % to 0.16 energy % combined with raising linoleic acid intake resulted in obesity and had detrimental consequences on organ function.

GABAergic promoter hypermethylation as a model to study the neurochemistry of schizophrenia vulnerability.

The neuronal GABAergic mechanisms that mediate the symptomatic beneficial effects elicited by a combination of antipsychotics with valproate (a histone deacetylase inhibitor) in the treatment of psychosis (expressed by schizophrenia or bipolar disorder patients) are unknown. This prompted us to investigate whether the beneficial action of this combination results from a modification of histone tail covalent esterification or is secondary to specific chromatin remodeling. The results suggest that clozapine, or sulpiride associated with valproate, by increasing DNA demethylation with an unknown mechanism, causes a chromatin remodeling that brings about a beneficial change in the epigenetic GABAergic dysfunction typical of schizophrenia and bipolar disorder patients.

Characterization of brain neurons that express enzymes mediating neurosteroid biosynthesis.

Allopregnanolone (ALLO) and tetrahydrodeoxycorticosterone (THDOC) are potent positive allosteric modulators of GABA action at GABA(A) receptors. ALLO and THDOC are synthesized in the brain from progesterone or deoxycorticosterone, respectively, by the sequential action of two enzymes: 5alpha-reductase (5alpha-R) type I and 3alpha-hydroxysteroid dehydrogenase (3alpha-HSD). This study evaluates 5alpha-R type I and 3alpha-HSD mRNA expression level in mouse brain by using in situ hybridization combined with glutamic acid decarboxylase 67/65, vesicular glutamate transporter 2, glial fibrillary acidic protein, and S100beta immunohistochemistry. We demonstrate that 5alpha-R type I and 3alpha-HSD colocalize in cortical, hippocampal, and olfactory bulb glutamatergic principal neurons and in some output neurons of the amygdala and thalamus. Neither 5alpha-R type I nor 3alpha-HSD mRNAs are expressed in S100beta- or glial fibrillary acidic protein-positive glial cells. Using glutamic acid decarboxylase 67/65 antibodies to mark GABAergic neurons, we failed to detect 5alpha-R type I and 3alpha-HSD in cortical and hippocampal GABAergic interneurons. However, 5alpha-R type I and 3alpha-HSD are significantly expressed in principal GABAergic output neurons, such as striatal medium spiny, reticular thalamic nucleus, and cerebellar Purkinje neurons. A similar distribution and cellular location of neurosteroidogenic enzymes was observed in rat brain. Taken together, these data suggest that ALLO and THDOC, which can be synthesized in principal output neurons, modulate GABA action at GABA(A) receptors, either with an autocrine or a paracrine mechanism or by reaching GABA(A) receptor intracellular sites through lateral membrane diffusion.

In psychosis, cortical interneurons overexpress DNA-methyltransferase 1.

Cortical DNA-methyltransferase 1 (DNMT1) is preferentially expressed in interneurons secreting GABA where it very likely contributes to promoter CpG island hypermethylation, thus causing a down-regulation of promoter functions. To consolidate and expand on previous findings that, in the cortex of schizophrenia (SZ) brains, glutamic acid decarboxylase 67 (GAD67) expression is down-regulated whereas that of DNMT1 is up-regulated, we studied both parameters in Brodmann's area (BA) 9 from the McLean 66 Cohort Collection (Harvard Brain Tissue Resource Center, Belmont, MA). In BA9 of SZ and bipolar disorder patients with psychosis, DNMT1 mRNA and protein expression preferentially increases in layer I, II, and IV interneurons, and this increase is paralleled by a decreased number of GAD67 mRNA-positive neurons. The increase in DNMT1 and the decrease in GAD67-expressing neurons were unrelated to postmortem interval, pH, RNA quality, or to the presence, dose, or duration of antipsychotic (APS) medication, with the exception of a subgroup of SZ patients treated with a combination of valproate and APS in which the expression of DNMT1 failed to change. The DNMT1 increase and the GAD67 decrease in BA9 interneurons are significant features of SZ and bipolar disorder with psychosis. Interestingly, the DNMT1 increase failed to occur when patients with psychosis received a combination of valproate and APS treatment but not APS monotherapy.