Increased cerebrospinal fluid interleukin-6 levels in patients with schizophrenia and those with major depressive disorder

Elevated peripheral levels of interleukin-6 (IL-6) are common findings in schizophrenia and depression. However, previous studies that measured cerebrospinal fluid (CSF) IL-6 levels in these disorders reported controversial results. The present study examined whether CSF IL-6 levels are altered in patients with schizophrenia and those with depression. Lumbar punctures were performed in 32 patients with schizophrenia, 30 with major depressive disorder (MDD), and 35 healthy controls. Serum samples were simultaneously collected from all subjects in the patient groups and from 32 of the control group. CSF and serum IL-6 levels were determined by enzyme-linked immunosorbent assay. Both the patients with schizophrenia and MDD had significantly higher CSF IL-6 levels compared to the controls (schizophrenia: P = 0.0027; MDD: P = 0.012). IL-6 levels were significantly higher in the CSF than in the serum. No significant correlation was observed between CSF and serum IL-6 levels. The present findings suggest that IL-6 of central origin is associated with the pathophysiology of schizophrenia and MDD, although confounding effect of smoking status can not be entirely excluded.

Effects of the CACNA1C risk allele on neurocognition in patients with schizophrenia and healthy individuals

Recent genetic association studies have identified the A-allele of rs1006737 within CACNA1C as a risk factor for schizophrenia as well as mood disorders. Some evidence suggests that this polymorphism plays a role in cognitive function both in schizophrenia patients and healthy individuals; however, the precise nature of this association remains unclear. Here we investigated the possible association of this polymorphism with a wide range of neurocognitive functions in schizophrenia patients and in healthy subjects. Schizophrenia patients exhibited significantly poorer performance on all the cognitive domains as compared to healthy controls. In patients, A-allele carriers demonstrated significantly worse logical memory performance than the G-allele homozygotes. In controls, no significant association was observed between the genotype and any of the cognitive domains examined. These results add to the literature suggesting that rs1006737 may be associated with schizophrenia through its detrimental effect on endophenotypic traits.

Negative correlation between cerebrospinal fluid oxytocin levels and negative symptoms of male patients with schizophrenia

BACKGROUND

Accumulating evidence indicates that oxytocin plays an important role in social interactions. Previous studies also suggest altered oxytocin function in patients with schizophrenia and depression. However, few studies have examined the central oxytocin levels in these disorders.

METHODS

Cerebrospinal fluid (CSF) oxytocin levels were measured by ELISA in male participants consisting of 27 patients with schizophrenia, 17 with major depressive disorder (MDD), and 21 healthy controls.

RESULTS

CSF oxytocin levels of patients with schizophrenia or MDD did not differ significantly with healthy controls. The antidepressant dose or the Hamilton depression rating scale score did not significantly correlate with the oxytocin levels in MDD patients. CSF oxytocin levels in schizophrenic patients significantly negatively correlated with second generation antipsychotic dose (r=-0.49, P=0.010) but not with first generation antipsychotic dose (r=-0.13, P=0.50). A significant correlation was observed between oxytocin levels and negative subscale of PANSS (r=-0.38, P=0.050). This correlation remained significant even after controlling for second generation antipsychotic dose (r=-0.47, P=0.016).

CONCLUSIONS

We obtained no evidence of altered CSF oxytocin levels in patients with schizophrenia or those with MDD. However, lower oxytocin levels may be related to higher second generation antipsychotic dose and more severe negative symptoms in schizophrenia.

Relationship between apathy and diffusion tensor imaging metrics of the brain in Alzheimer's disease

OBJECTIVE

Alzheimer's disease (AD) research has largely concentrated on the study of cognitive decline, but the associated behavioral and neuropsychiatric symptoms are of equal importance in the clinical profile of the disease. Apathy is the most common neuropsychiatric manifestation in AD. Clinical, multimodal neuroimaging studies and pathologic studies of apathy in AD have suggested an association with frontal dysfunction but without a definitive localization. In this study, we examined the association between apathy and white matter integrity using diffusion tensor imaging (DTI).

METHODS

Twenty-one AD patients underwent DTI and neuropsychiatric and cognitive assessments. All fractional anisotropy (FA) maps were normalized to the standard space, and the association between the apathy scale and DTI metrics were evaluated voxel basically.

RESULTS

Statistical parametric mapping analysis showed that there were statistically negative correlations between the apathy scale and FA values in the right anterior cingulate, right thalamus, and bilateral parietal regions using age, Mini-Mental State Examination score and sex as nuisance variables.

CONCLUSIONS

Apathy in AD is associated with impaired white matter integrity in the anterior cingulate and medial thalamus. These results reinforce the confluence of evidence from other investigational modalities in implicating limbic dysfunction and related neuronal circuits in the neurobiology of apathy in AD.

Prophylactic and therapeutic efficacies of a selective inhibitor of the immunoproteasome for Hashimoto's thyroiditis, but not for Graves' hyperthyroidism, in mice

Major histocompatibility complex (MHC) class I-restricted T cell epitopes are generated mainly by the immunoproteasome in antigen-presenting cells. Therefore, inhibition of activity of this proteolytic complex molecule is thought to be a potential treatment for cell-mediated autoimmune diseases. We therefore studied the efficacy of an immunoproteasome inhibitor, ONX 0914 (formerly PR-957), for the treatment of autoimmune thyroid diseases, including cell-mediated Hashimoto's thyroiditis and autoantibody-mediated Graves' hyperthyroidism using mouse models. Our data show that ONX 0914 was effective prophylactically and therapeutically at suppressing the degree of intrathyroidal lymphocyte infiltration and, to a lesser degree, the titres of anti-thyroglobulin autoantibodies in non-obese diabetic (NOD)-H2(h4) mice, an iodine-induced autoimmune thyroiditis model. It also inhibited differentiation of T cells to T helper type 1 (Th1) and Th17 cells, effector T cell subsets critical for development of thyroiditis in this mouse strain. In contrast, its effect on the Graves' model was negligible. Although ONX 0914 exerts its immune-suppressive effect through not only suppression of immune proteasome but also other mechanism(s), such as inhibition of T cell differentiation, the present results suggest that the immunoproteasome is a novel drug target in treatment of Hashimoto's thyroiditis in particular and cell-mediated autoimmune diseases in general.

Postmortem findings in a patient with cerebral amyloid angiopathy actively treated with corticosteroid

We examined histopathological changes in cerebrovascular amyloid deposition in a patient with cerebral amyloid angiopathy receiving corticosteroid therapy. A 69-year-old female developed subacute onset cognitive decline, and magnetic resonance image (MRI) showed subarachnoid hemorrhage with leptomeningeal enhancement. She entered in an apathetic state due to communicating hydrocephalus and a ventricle-peritoneal (V-P) shunt operation was performed. Brain biopsy disclosed multiple cortical microhemorrhages and severe Congophilic angiopathy with positive Aβ-immunoreactivity in most vessels. Inflammatory mononuclear cells surrounded a few severe amyloid-laden leptomeningeal vessels. She received high-dose corticosteroid, which was slowly tapered. She gradually recovered but finally died 1.5 years later with no recurrence of CAA-related hemorrhages. Postmortem examination of the brain showed multiple old microhemorrhages in the cortex and extensive degeneration of cerebral white matter. The cortical and leptomeningeal vascular walls showed a few Congophilic amyloid deposits, but small deposits with Aβ-immunoreactivity were frequently seen. There was no infiltration of inflammatory cells in either leptomeninges or vascular walls. Electron microscopy revealed sparse aggregation of amyloid fibrils in significant numbers of vascular walls. Biochemical analysis disclosed that Aβ1-40-immunoreactive amyloid protein fractions obtained from the patient's leptomeninges were very small in amount. Comparing the previous biopsy findings with those at autopsy, the total disappearance of the inflammatory cell infiltration and diminishing of the cerebrovascular amyloid deposits were noted.

Association of plasma IL-6 and soluble IL-6 receptor levels with the Asp358Ala polymorphism of the IL-6 receptor gene in schizophrenic patients

Recent studies indicate a role of excessive interleukin-6 (IL-6) signaling in the pathogenesis of schizophrenia. A previous study reported a significant association of schizophrenia with the IL-6 receptor (IL-6R) gene Asp358Ala polymorphism, which is known to regulate circulating IL-6 and soluble IL-6R (sIL-6R) levels in healthy subjects. To further examine the influence of the polymorphism in schizophrenic patients, we compared the plasma levels of IL-6 and sIL-6R between schizophrenic patients and healthy controls for each genotype of the Asp358Ala polymorphism. Asp358Ala genotyping and plasma IL-6 level measurements were performed in 104 patients with schizophrenia and 112 healthy controls. Of these participants, 53 schizophrenic patients and 49 controls were selected for the measurement of plasma sIL-6R levels. A two-way factorial analysis of covariance was performed with the transformed plasma levels as the dependent variable, diagnosis and genotype as independent variables, and sex and age as covariates. No significant diagnosis × genotype interaction was observed for IL-6 and sIL-6R levels. The Ala allele of Asp358Ala was significantly associated with higher levels of both IL-6 and sIL-6R. IL-6 levels were significantly elevated in schizophrenic patients compared to those in controls, whereas no significant difference in sIL-6R levels was observed between schizophrenic patients and controls. Our findings suggest that the presence of schizophrenia is associated with elevated IL-6 levels, whereas sIL-6R levels are mainly predetermined by the Asp358Ala genotype and are not associated with the disease status. Increased IL-6 levels without alterations in sIL-6R levels may result in excessive IL-6 signaling in schizophrenia.

Phosphorylated Syk expression is enhanced in Nasu-Hakola disease brains

Nasu-Hakola disease (NHD) is a rare autosomal recessive disorder, characterized by progressive presenile dementia and formation of multifocal bone cysts, caused by a loss-of-function mutation of DNAX-activation protein 12 (DAP12) or triggering receptor expressed on myeloid cells 2 (TREM2). TREM2 and DAP12 constitute a receptor/adaptor complex on myeloid cells. The post-receptor signals are transmitted via rapid phosphorylation of the immunoreceptor tyrosine-based activating motif (ITAM) of DAP12, mediated by Src protein tyrosine kinases, followed by binding of phosphorylated ITAM to Src homology 2 (SH2) domains of spleen tyrosine kinase (Syk), resulting in autophosphorylation of the activation loop of Syk. To elucidate the molecular mechanism underlying the pathogenesis of NHD, we investigated Syk expression and activation in the frontal cortex and the hippocampus of three NHD and eight control brains by immunohistochemistry. In NHD brains, the majority of neurons expressed intense immunoreactivities for Syk and Y525/Y526-phosphorylated Syk (pSyk) chiefly located in the cytoplasm, while more limited populations of neurons expressed Src. The levels of pSyk expression were elevated significantly in NHD brains compared with control brains. In both NHD and control brains, substantial populations of microglia and macrophages expressed pSyk, while the great majority of reactive astrocytes and myelinating oligodendrocytes did not express pSyk, Syk or Src. These observations indicate that neuronal expression of pSyk was greatly enhanced in the cerebral cortex and the hippocampus of NHD brains, possibly via non-TREM2/DAP12 signaling pathways involved in Syk activation.

Expression of Ca²⁺-dependent activator protein for secretion 2 is increased in the brains of schizophrenic patients

Ca(2+)-dependent activator protein for secretion 2 (CADPS2), a secretory granule associate protein, mediates monoamine transmission and the release of neurotrophins including brain-derived neurotrophic factor (BDNF) which have been implicated in psychiatric disorders. Furthermore, the expression of CADPS2deltaExon3, a defective splice variant of CADPS2, has been reported to be associated with autism. Based on these observations, we examined whether expression levels of CADPS2 and CADPS2deltaExon3 are altered in psychiatric disorders. Quantitative polymerase chain reaction analysis was performed for postmortem frontal cortex tissues (BA6) from 15 individuals with schizophrenia, 15 with bipolar disorder, 15 with major depression, and 15 controls (Stanley neuropathology consortium). The mean CADPS2 expression levels normalized to human glyceraldehyde-3phosphate dehydrogenase (GAPDH) or TATA-box binding protein levels was found to be significantly increased in the brains of the schizophrenia group, compared to the control group. On the other hand, the ratio of CADPS2deltaExon3 to total CADPS2 was similar in the 4 diagnostic groups. We then analyzed CADPS2 expression in blood samples from 121 patients with schizophrenia and 318 healthy controls; however, there was no significant difference between the two groups. Chronic risperidone treatment did not alter the expression of CADPS2 in frontal cortex of mice. The observed increase in the expression of CADPS2 may be related to the impaired synaptic function in schizophrenia.

Criterion and construct validity of the CogState Schizophrenia Battery in Japanese patients with schizophrenia

Background

The CogState Schizophrenia Battery (CSB), a computerized cognitive battery, covers all the same cognitive domains as the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Consensus Cognitive Battery but is briefer to conduct. The aim of the present study was to evaluate the criterion and construct validity of the Japanese language version of the CSB (CSB-J) in Japanese patients with schizophrenia.

Methodology/Principal Findings

Forty Japanese patients with schizophrenia and 40 Japanese healthy controls with matching age, gender, and premorbid intelligence quotient were enrolled. The CSB-J and the Brief Assessment of Cognition in Schizophrenia, Japanese-language version (BACS-J) were performed once. The structure of the CSB-J was also evaluated by a factor analysis. Similar to the BACS-J, the CSB-J was sensitive to cognitive impairment in Japanese patients with schizophrenia. Furthermore, there was a significant positive correlation between the CSB-J composite score and the BACS-J composite score. A factor analysis showed a three-factor model consisting of memory, speed, and social cognition factors.

Conclusions/Significance

This study suggests that the CSB-J is a useful and rapid automatically administered computerized battery for assessing broad cognitive domains in Japanese patients with schizophrenia.

Cerebral small-vessel disease protein HTRA1 controls the amount of TGF-β1 via cleavage of proTGF-β1

Cerebral small-vessel disease is a common disorder in elderly populations; however, its molecular basis is not well understood. We recently demonstrated that mutations in the high-temperature requirement A (HTRA) serine peptidase 1 (HTRA1) gene cause a hereditary cerebral small-vessel disease, cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL). HTRA1 belongs to the HTRA protein family, whose members have dual activities as chaperones and serine proteases and also repress transforming growth factor-β (TGF-β) family signaling. We demonstrated that CARASIL-associated mutant HTRA1s decrease protease activity and fail to decrease TGF-β family signaling. However, the precise molecular mechanism for decreasing the signaling remains unknown. Here we show that increased expression of ED-A fibronectin is limited to cerebral small arteries and is not observed in coronary, renal arterial or aortic walls in patients with CARASIL. Using a cell-mixing assay, we found that HTRA1 decreases TGF-β1 signaling triggered by proTGF-β1 in the intracellular space. HTRA1 binds and cleaves the pro-domain of proTGF-β1 in the endoplasmic reticulum (ER), and cleaved proTGF-β1 is degraded by ER-associated degradation. Consequently, the amount of mature TGF-β1 is reduced. These results establish a novel mechanism for regulating the amount of TGF-β1, specifically, the intracellular cleavage of proTGF-β1 in the ER.

Absence of small-vessel abnormalities in alternating hemiplegia of childhood

OBJECTIVE

To investigate whether Japanese patients with alternating hemiplegia of childhood (AHC) have the similar small-vessel abnormalities in skin reported in European patients with AHC.

METHODS

Electron microscopic observation of biopsied skin specimens were carried out in six Japanese patients with AHC. All patients (aged 5-17, all boys) had been diagnosed with AHC through their typical clinical courses and symptoms.

RESULTS

No abnormal findings in both endothelial cells and smooth muscle cells in skin small-vessels were obtained in the present study, either in the five flunarizine responders or in the one non-responder.

CONCLUSIONS

From our observations, we hypothesized that there may be some subtypes of AHC. The diverse clinical courses in patients with AHC and the differing efficacy of flunarizine treatment could be explained because of the heterogeneity of AHC subtypes.

Possible association of the semaphorin 3D gene (SEMA3D) with schizophrenia

Semaphorins are ligands of plexins, and the plexin-semaphorin signaling system is widely involved in many neuronal events including axon guidance, cell migration, axon pruning, and synaptic plasticity. The plexin A2 gene (PLXNA2) has been reported to be associated with schizophrenia. This finding prompted us to examine the possible association between the semaphorin 3D gene (SEMA3D) and schizophrenia in a Japanese population. We genotyped 9 tagging single nucleotide polymorphisms (SNPs) of SEMA3D including a non-synonymous variation, Lys701Gln (rs7800072), in a sample of 506 patients with schizophrenia and 941 healthy control subjects. The Gln701 allele showed a significant protective effect against the development of schizophrenia (p = 0.0069, odds ratio = 0.76, 95% confidence interval 0.63 to 0.93). Furthermore, the haplotype-based analyses revealed a significant association. The four-marker analysis (rs2190208-rs1029564-rs17159614-rs12176601), in particular, not including the Lys701Gln, revealed a highly significant association (p = 0.00001, global permutation), suggesting that there may be other functional polymorphisms within SEMA3D. Our findings provide strong evidence that SEMA3D confers susceptibility to schizophrenia, which could contribute to the neurodevelopmental impairments in the disorder.

[Research resource network and Parkinson disease brain bank donor registration program in Japan]

In spite of the increasing need for brain tissue in biomedical research, overall brain banking activities in Japan has been lagging behind. On the initiative of the National Center of Neurology and Psychiatry, 2 projects have been carried out; the Research Resource Network (RRN) and the Parkinson's Disease Brain Bank (PDBB) donor registration program. RRN is a nation-wide network that links 15 brain repositories, and 1,463 autopsy brains have been registered in this network as of December 2009. The brain donor registration program for PDBB was established in 2006. A donor without cognitive impairment can enroll in this PDBB donor registration program. When the donor dies, the next-of-kin will contact the PDBB coordinators for subsequent autopsy services and brain retention. On obtaining the next-of-kin's consent at the time of donor's death, autopsy will be performed at PDBB collaborating hospitals of National Center of Neurology and Psychiatry, Juntendo University Hospital, and Tokyo Metropolitan Geriatric Hospital. In order to arouse public interest, lecture meetings for citizens have been held on a regular basis. Fifty individuals have registered in the PDBB donor registration program including 27 patients with PD, 4 patient with Parkinson syndrome, 1 patient with progressive supranuclear palsy, and 18 individuals without PD or related disorders as of December 2009. Autopsies have been performed for 2 of these donors. To promote brain banking activities,it is necessary to establish legal and ethical guidelines for the use of autopsied materials in biomedical research.

Contribution of anti-CCP antibodies, proximal interphalangeal joint involvement, HLA-DRB1 shared epitope, and PADI4 as risk factors for the development of rheumatoid arthritis in palindromic rheumatism

OBJECTIVES

To determine which variables at baseline are predictive for the development of rheumatoid arthritis (RA) from palindromic rheumatism (PR) in a Japanese population.

METHODS

Anti-cyclic citrullinated peptide (anti-CCP) antibodies, joint involvement pattern, genotypes of HLA-DRB1, peptidylarginine deiminase (PADI4), and protein tyrosine phosphatase (PTPN22) were examined in 28 patients with PR at baseline, and their clinical outcome was prospectively evaluated. The same variables were also investigated in 38 healthy controls.

RESULTS

Eleven out of 28 patients with PR developed RA. The prevalence of anti-CCP antibodies in the PR patients who developed RA was significantly higher compared to the patients who did not. Proximal interphalangeal (PIP) joint involvement at baseline was also predictive towards the development of RA. Compared with the controls, differences in the frequency of single-nucleotide polymorphism (SNP) on padi4_104 [T(RA susceptible)-->C(RA non-susceptible)] and the presence of an RA susceptible homozygote of the PADI4 haplotype were detected in patients with PR whereas we could not find any further difference in PR patients who developed RA compared to PR patients who do not develop RA in PADI4. None of the subjects possessed the PTPN22 SNP (1858C-->T). Cox regression analysis revealed that anti-CCP antibodies as well as PIP involvement are the most relevant variables for the development of RA from PR. None of the PR patients with either HLA-DRB1*SE alleles (or the HLA-DRB1*0405 allele) or anti-CCP antibodies developed RA.

CONCLUSIONS

Anti-CCP antibodies, in relation to HLA-DRB1*SE carriership, and PIP involvement are predictive for the development of RA from PR in the Japanese population.

Milk-clotting Enzyme from Microorganisms: V. Purification and Crystallization of Mucor Rennin from Mucor pusillus var. Lindt

A rennin crystal was obtained from the crude milk-clotting enzyme of Mucor pusillus var. Lindt. The crude enzyme was purified by using columns of Amberlite CG-50, diethylaminoethyl Sephadex A-50, and Sephadex G-100. This purified enzyme was dissolved in 0.1 M sodium acetate (pH 5.0) buffer to a final concentration of 2 to 3%; ammonium sulfate (to 40% saturation) was added, and the resulting solution was placed in cellophane tubes. The enzyme solution was dialyzed against 0.1 M sodium acetate buffer (pH 5) containing ammonium sulfate was added dropwise to the outside solution of the cellophane tube, and the concentration of ammonium sulfate in the cellophane tube increased gradually. The crystals of enzyme were formed in the cellophane tube when the concentration reached approximately 50% saturation. After the enzyme solution was concentrated in the freezer, the crystals were obtained. The activity of the crystalline enzyme was inhibited by Hg, Ag, Zn, and KMnO(4).