Cytosolic persistence of mouse brain CYP1A1 in chronic heme deficiency

Previous work has demonstrated that the function of extrahepatic cytochrome P450 CYP1A1 is dependent on the availability of heme. CYP1A1 is involved in the activation of polyaromatic hydrocarbons. In the present study we used a transgenic mouse model with chronic impairment of heme synthesis - female porphobilinogen deaminase-deficient (PBGD-/-) mice - to investigate the effects of limited heme in untreated and β-naphthoflavone (β-NF)-treated animals on the function of CYP1A1 in brain. The heme content of PBGD-/- mice was diminished in the liver and brain compared to wild types. In the liver, partial heme deficiency led to less potent induction of CYP1A1 mRNA after β-NF treatment. In the brain, CYP1A1 protein was detected not only at the endoplasmic reticulum (ER), but also in the cytosol of PBGD-/- mice. Furthermore, 7-deethylation of ethoxyresorufin, an indicator of CYP1A1 metabolic activity, could be restored by heme in cytosol of PBGD-/- mouse brain. Independent of the genotype, we found only one cyp1a1 gene product, indicating that the cytosolic appearance of CYP1A1 most likely did not originate from mutant alleles. We conclude that heme deficiency in the brain leads to incomplete heme saturation of CYP1A1, which causes its improper incorporation into the ER membrane and persistence in the cytosol. It is suggested that diseases caused by relative heme deficiency, such as hepatic porphyrias, may lead to impaired hemoprotein function in brai

Psychiatric staff on the wards does not share attitudes on aggression

Peer reviewe

Genomics and proteomics: role in the management of multiple sclerosis

Epidemiological studies and neuro-imaging have provided important insights into the natural course and prognostic factors of multiple sclerosis (MS), but our ability to predict different courses of the disease, and especially its response to treatment, is still very limited. Pharmacogenetic, pharmacogenomic and proteomic studies aim to assess gene and protein function in disease and promise to help to fill this important gap in our knowledge. Such studies may increase our understanding of disease mechanisms and responses to therapeutic compounds. Large-scale transcriptional expression profiling can be performed using gene chip microarrays; this technology allows screening for differentially expressed genes without having well-defined underlying hypotheses ("discovery-driven research”). To complement the technique, real time reverse transcription and polymerase chain reaction (RT-PCR) can be used for more targeted profiling and provides quantitative data on pre-selected genes. However, to maximise their clinical utility, expression profiling results need to be combined with well-documented clinical and imaging data. Two forthcoming studies will investigate the long-term effects of early treatment with interferon beta-1b (IFNβ) on the course of MS. The BENEFIT (BEtaseron®/Betaferon® in Newly Emerging MS for Initial Treatment) study will incorporate pharmacogenetic and pharmacogenomic analyses to determine the genetic elements controlling treatment response. BEST-PGx (Betaferon®/Betaseron® in Early relapsing-remitting MS Surveillance Trial—Pharmacogenomics) is an exploratory 2-year study that will investigate the value of RNA expression profiling and pharmacogenetics in predicting treatment response to IFNβ in patients with early relapsing MS. The main goal of BEST-PGx is the identification of differences in gene expression profiles of patients showing differential treatment responses. In addition, this study may reveal new information relevant to the mechanism of action of interferon treatment in MS and also to differences in the underlying pathology of the immune system. These data may help us approach the goal of a really "individualised therapy” with increased efficacy, reduced adverse drug reactions and more efficient use of healthcare resource

Antimyelin antibodies in clinically isolated syndromes correlate with inflammation in MRI and CSF

Objective: We investigated the correlation of anti-myelin oligodendrocyte glycoprotein- (anti-MOG) and anti-myelin basic protein antibodies (anti-MBP) in serum of CIS patients with inflammatory signs in MRI and in CSF and, as previously suggested, the incidence of more frequent and rapid progression to clinically definite MS (CDMS). Methods: 133 CIS patients were analysed for anti-MOG and anti-MBP (Western blot). Routine CSF and cranial MRI (quantitatively and qualitatively) measures were analyzed. 55 patients had a follow-up of at least 12 months or until conversion to CDMS. Results: Patients with anti-MOG and anti-MBP had an increased intrathecal IgG production and CSF white blood cell count (p = 0.048 and p = 0.036). When anti-MBP alone, or both antibodies were present the cranial MRI showed significantly more T2 lesions (p = 0.007 and p = 0.01, respectively). There was a trend for more lesion dissemination in anti-MBP positive patients (p = 0.076). Conversely, anti-MOG- and/or anti-MBP failed to predict conversion to CDMS in our follow-up group (n = 55). Only in female patients with at least one MRI lesion (n = 34) did the presence of anti-MOG correlate with more frequent (p = 0.028) and more rapid (p = 0.0209) transition to CDMS. Conclusions: Presence of anti-MOG or anti-MBP or both was not significantly associated with conversion to CDMS in our CIS cohort. However, patients with anti-MOG and anti-MBP had higher lesion load and more disseminated lesions in cranial MRI as well as higher values for CSF leucocytes and intrathecal IgG production. Our data support a correlation of anti-MOG and anti-MBP to inflammatory signs in MRI and CSF. The prognostic value of these antibodies for CDMS, however, seems to be less pronounced than previously reporte

Neutralizing antibodies against IFN‐β in multiple sclerosis: antagonization of IFN‐β mediated suppression of MMPs

Neutralizing antibodies (NAb) against interferon‐β (IFN‐β) develop in about a third of treated multiple sclerosis patients and are believed to reduce therapeutic efficacy of IFN‐β on clinical and MRI measures. The expression of the interferon acute‐response protein, myxovirus resistance protein A (MxA) is a sensitive measure of the biological activity of therapeutically applied IFN‐β and of its reduced bioavailability due to NAb. However, MxA may not be operative in the pathogenesis of multiple sclerosis or the therapeutic effect of IFN‐β. Instead, matrix metalloproteinases (MMPs) are increased in brain tissue, CSF and blood circulation of multiple sclerosis patients and function as effector molecules in several steps of multiple sclerosis pathogenesis. One of the molecular mechanisms by which IFN‐β exerts its beneficial effect in multiple sclerosis is reduction of MMP‐9 expression and increase of its endogenous tissue inhibitor, TIMP‐1. Quantitative PCR measurements of MMP‐2 and MMP‐9, TIMP‐1 and TIMP‐2, and MxA were performed in peripheral mononuclear cells from clinically stable multiple sclerosis patients with relapsing remitting disease course after short‐term and long‐term treatment with IFN‐β. IFN‐β therapy down‐regulated the expression of MMP‐9 and abolished that of MMP‐2 in long‐term, but not short‐term treated multiple sclerosis, while levels of MxA were increased in both instances. The presence of NAb reversed these effects, i.e. led to reduced MxA and increased MMP‐2/MMP‐9 expression levels compared with NAb- patients. In contrast, expression of TIMPs in peripheral blood mononuclear cells remained unaffected by IFN‐β therapy and the presence of NAb. While MxA is able to detect the biological action and reduced bioavailability of IFN‐β on the basis of single injections, only MMP‐9 shows quantitative correlation with the NAb titre. Together with evidence that an imbalance between MMP and TIMP expression is a crucial pathogenetic feature in multiple sclerosis, these findings support the concept of a significant role of NAb in reducing the therapeutic efficacy of IFN‐

Anabolic and catabolic responses of human articular chondrocytes to varying oxygen percentages

Oxygen is a critical parameter proposed to modulate the functions of chondrocytes ex-vivo as well as in damaged joints. This article investigates the effect of low (more physiological) oxygen percentage on the biosynthetic and catabolic activity of human articular chondrocytes (HAC) at different phases of in vitro culture

Interventions following a high violence risk assessment score : a naturalistic study on a Finnish psychiatric admission ward

Background: Patient aggression and violence against staff members and other patients are common concerns in psychiatric units. Many structured clinical risk assessment tools have recently been developed. Despite their superiority to unaided clinical judgments, staff has shown ambivalent views towards them. A constant worry of staff is that the results of risk assessments would not be used. The aims of the present study were to investigate what were the interventions applied by the staff of a psychiatric admission ward after a high risk patient had been identified, how frequently these interventions were used and how effective they were. Methods: The data were collected in a naturalistic setting during a 6-month period in a Finnish psychiatric admission ward with a total of 331 patients with a mean age of 42.9 years (SD 17.39) suffering mostly from mood, schizophrenia-related and substance use disorders. The total number of treatment days was 2399. The staff assessed the patients daily with the Dynamic Appraisal of Situational Aggression (DASA), which is a structured violence risk assessment considering the upcoming 24 h. The interventions in order to reduce the risk of violence following a high DASA total score (>= 4) were collected from the patients' medical files. Inductive content analysis was used. Results: There were a total of 64 patients with 217 observations of high DASA total score. In 91.2% of cases, at least one intervention aiming to reduce the violence risk was used. Pro re nata (PRN)-medication, seclusion and focused discussions with a nurse were the most frequently used interventions. Non-coercive and non-pharmacological interventions like daily activities associated significantly with the decrease of perceived risk of violence. Conclusion: In most cases, a high score in violence risk assessment led to interventions aiming to reduce the risk. Unfortunately, the most frequently used methods were psychopharmacological or coercive. It is hoped that the findings will encourage the staff to use their imagination when choosing violence risk reducing intervention techniques.Peer reviewe

Cocapture of cognate and bystander antigens can activate autoreactive B cells

Autoantibodies against myelin oligodendrocyte glycoprotein (MOG) are associated with autoimmune central nervous system diseases like acute disseminated encephalomyelitis (ADEM). For ADEM, it is speculated that a preceding infection is the trigger of the autoimmune response, but the mechanism connecting the infection to the production of MOG antibodies remains a mystery. We reasoned that the ability of B cells to capture cognate antigen from cell membranes, along with small quantities of coexpressed “bystander” antigens, might enable B-cell escape from tolerance. We tested this hypothesis using influenza hemagglutinin as a model viral antigen and transgenic, MOG-specific B cells. Using flow cytometry and live and fixed cell microscopy, we show that MOG-specific B cells take up large amounts of MOG from cell membranes. Uptake of the antigen from the membrane leads to a strong activation of the capturing B cell. When influenza hemagglutinin is also present in the membrane of the target cell, it can be cocaptured with MOG by MOG-specific B cells via the B-cell receptor. Hemagglutinin and MOG are both presented to T cells, which in turn are activated and proliferate. As a consequence, MOG-specific B cells get help from hemagglutinin-specific T cells to produce anti-MOG antibodies. In vivo, the transfer of MOG-specific B cells into recipient mice after the cocapture of MOG and hemagglutinin leads to the production of class-switched anti-MOG antibodies, dependent on the presence of hemagglutinin-specific T cells. This mechanism offers a link between infection and autoimmunity. Keywords: tolerance; autoantibodies; antigen capture; antigen presentation; influenz

Anti-MOG antibodies are present in a subgroup of patients with a neuromyelitis optica phenotype

Background: Antibodies against myelin oligodendrocyte glycoprotein (MOG) have been identified in a subgroup of pediatric patients with inflammatory demyelinating disease of the central nervous system (CNS) and in some patients with neuromyelitis optica spectrum disorder (NMOSD). The aim of this study was to examine the frequency, clinical features, and long-term disease course of patients with anti-MOG antibodies in a European cohort of NMO/NMOSD. Findings: Sera from 48 patients with NMO/NMOSD and 48 patients with relapsing-remitting multiple sclerosis (RR-MS) were tested for anti-aquaporin-4 (AQP4) and anti-MOG antibodies with a cell-based assay. Anti-MOG antibodies were found in 4/17 patients with AQP4-seronegative NMO/NMOSD, but in none of the AQP4-seropositive NMO/NMOSD (n = 31) or RR-MS patients (n = 48). MOG-seropositive patients tended towards younger disease onset with a higher percentage of patients with pediatric (<18 years) disease onset (MOG+, AQP4+, MOG-/AQP4-: 2/4, 3/31, 0/13). MOG-seropositive patients presented more often with positive oligoclonal bands (OCBs) (3/3, 5/29, 1/13) and brain magnetic resonance imaging (MRI) lesions during disease course (2/4, 5/31, 1/13). Notably, the mean time to the second attack affecting a different CNS region was longer in the anti-MOG antibody-positive group (11.3, 3.2, 3.4 years). Conclusions: MOG-seropositive patients show a diverse clinical phenotype with clinical features resembling both NMO (attacks mainly confined to the spinal cord and optic nerves) and MS with an opticospinal presentation (positive OCBs, brain lesions). Anti-MOG antibodies can serve as a diagnostic and maybe prognostic tool in patients with an AQP4-seronegative NMO phenotype and should be tested in those patients

Gut microbiota composition as a candidate risk factor for dimethyl fumarate-induced lymphopenia in multiple sclerosis

Mounting evidence points towards a pivotal role of gut microbiota in multiple sclerosis (MS) pathophysiology. Yet, whether disease-modifying treatments alter microbiota composition and whether microbiota shape treatment response and side-effects remain unclear. In this prospective observational pilot study, we assessed the effect of dimethyl fumarate (DMF) on gut microbiota and on host/microbial metabolomics in a cohort of 20 MS patients. Combining state-of-the-art microbial sequencing, metabolome mass spectrometry, and computational analysis, we identified longitudinal changes in gut microbiota composition under DMF-treatment and an increase in citric acid cycle metabolites. Notably, DMF-induced lymphopenia, a clinically relevant safety concern, was correlated with distinct baseline microbiome signatures in MS patients. We identified gastrointestinal microbiota as a key therapeutic target for metabolic properties of DMF. By characterizing gut microbial composition as a candidate risk factor for DMF-induced lymphopenia, we provide novel insights into the role of microbiota in mediating clinical side-effects