Biology subjects

Maes, M.

Publications and source records attributed to Maes, M..

4 recordsLinked to original sources

bioRxiv2018

Paranoid schizophrenia and methamphetamine-induced paranoia are both characterized by a similar LINE-1 partial methylation profile, which is more pronounced in paranoid schizophrenia.

BackgroundThere is evidence that schizophrenia is a neuro-immune disorder. Genes linked to intragenic LINE-1 methylation show a strong association with immune-associated disorders including psychosis. The aim of this study was to examine LINE-1 methylation patterns in paranoid schizophrenia and methamphetamine-induced paranoia, a model for schizophrenia.\n\nMethodsThis study recruited 31 patients with paranoid schizophrenia, 94 with methamphetamine-induced paranoia (MIP) and 163 normal controls. LINE-1 methylation patterns were assayed in peripheral blood mononuclear cells and a combined bisulphite restriction analysis and COBRA were used to estimate global methylation (mC) and LINE-1 CpG dinucleotide methylation patterns, namely 2 methylated (mCmC) and 2 unmethylated (uCuC) CpGs and the partially methylated loci mCuC (5m with 3u) and uCmC (5u with 3m).\n\nResultsPatients with paranoid schizophrenia show highly significant changes in LINE-1 partial methylation patterns, namely a higher % mCuC and lower % uCmC as compared with controls and MIP patients, while the latter show higher % mCuC but lower % uCmC as compared with controls. Higher % mCuC significantly predicts paranoid schizophrenia with a sensitivity of 51.6%, specificity of 97.5% and an area under the ROC curve of 0.895.\n\nConclusionsThe results indicate that a common dysfunction in LINE-1 partial methylation may underpin both paranoid schizophrenia and MIP and that this methylation pattern is significantly more expressed in paranoid schizophrenia than MIP. Reciprocal links between impairments in LINE-1 methylation and neuro-immune and neuro-oxidative pathways may underpin the pathophysiology of both MIP and paranoid schizophrenia.

neuroscience↗

bioRxiv2018

Early Life Trauma Predicts Affective Phenomenology and the Effects are Partly Mediated by Staging Coupled with Lowered Lipid-Associated Antioxidant Defences.

BackgroundEarly life trauma (ELT) may drive mood disorder phenomenology, neuro-oxidative and neuro-immune pathways and impairments in semantic memory. Nevertheless, there are no data regarding the impact of ELT on affective phenomenology and whether these pathways are mediated by staging or lowered lipid-associated antioxidant defences.\n\nMethodsThis study examined healthy controls (n=54) and patients with affective disorders including major depression, bipolar disorder and anxiety disorders (n=118). ELT was assessed using the Child Trauma Questionnaire. In addition, we measured affective phenomenology and assayed advanced oxidation protein products; malondialdehyde, paraoxonase 1 (CMPAase) activity, high-sensitivity C-reactive protein (hsCRP), and high-density lipoprotein (HDL) cholesterol.\n\nResultsELT was associated with increased risk for mood and comorbid anxiety disorders and a more severe phenomenology, including staging characteristics (number of mood episodes), severity of depression and anxiety, suicide attempts, suicidal ideation, type of treatments received, disabilities, body mass index, smoking behaviour and hsCRP, as well as lowered health-related quality of life, socio-economic status, antioxidant defences and semantic memory. The number of mood episodes and CMPAase/HDL-cholesterol levels could be reliably combined into a new vulnerability staging-biomarker index, which mediates in part the effects of ELT on affective phenomenology, while lowered antioxidant defences are associated with increased oxidative stress. Moreover, the effects of female sex on mood disorders and affective phenomenology are mediated by ELT.\n\nDiscussionThe cumulative effects of different types of ELT drive many aspects of affective phenomenology either directly or indirectly through effects of staging and/or lipid-associated antioxidant defences. The results show that children, especially girls, with ELT are at great risk to develop mood disorders and more severe phenotypes of affective disorders.

neuroscience↗

bioRxiv2018

Supervised machine learning to decipher the complex associations between neuro-immune biomarkers and quality of life in schizophrenia

Stable phase schizophrenia is characterized by altered patterning in tryptophan catabolites (TRYCATs) and memory impairments, which are associated with PHEMN (psychosis, hostility, excitation, mannerism and negative) and DAPS (depression, anxiety and physio-somatic) symptoms. This study was carried out to examine the association between TRYCAT patterning, memory impairments, psychopathological features and health-related quality of life (HR-QoL) in schizophrenia.\n\nThe World Health Organization (WHO) QoL instrument-Abbreviated version (WHO-QoL-BREF), IgA/IgM responses to TRYCATs, cognitive tests, Scale for the Assessment of Negative Symptoms (SANS), Hamilton and Depression (HAMD) and Anxiety (HAMA) Rating Scales and the Fibromyalgia and Chronic Fatigue Syndrome Rating Scale (FF) were measured in 80 schizophrenia patients and 40 controls.\n\nNeural Network analysis shows that the total HR-Qol score is best predicted by (in descending order) FF, HAMA and SANS scores, Mini Mental State examination, hostility, ratio noxious/protective TRYCATs and HAMD score. Partial least Squares (PLS) analysis shows that 55.1% of the variance in Domain1 (physical) is predicted by PHEMN and DAPS latent vector (LV) scores, while 57.9% of domain2 (psychological), 32.7% of domain3 (social) and 55.0% of domain4 (environment) are explained by DAPS LV scores. TRYCATs and episodic/semantic memory impairments have specific indirect effects on domains 2, 3 and 4, which are mediated by DAPS symptoms, while the effects of TRYCATs on domain1 are mediated by PHEMN and DAPS symptoms. Picolinic acid, xanthurenic acid and 3-hydroxy-kynurenine decrease WHO-QoL scores, whilst anthranilic acid is protective.\n\nThe results show that lowered HR-Qol in schizophrenia is strongly predicted by noxious TRYCATs, impairments in episodic and semantic memory and DAPS symptoms, especially physio-somatic symptoms and anxiety. Neuro-immune pathways and the consequent cognitive impairments determine to a great extent lowered HR-QoL in schizophrenia.

neuroscience↗

bioRxiv2018

A new schizophrenia model: immune activation is associated with induction of thetryptophan catabolite pathway and increased eotaxin levels which together determinememory impairments and schizophrenia symptom dimensions.

AbstractO_ST_ABSObjectiveC_ST_ABSRecently, we reported that stable-phase schizophrenia is characterized by two interrelated symptom dimensions: PHEMN (psychotic, hostility, excitation, mannerism and negative symptoms); and DAPS (depressive, anxiety and physio-somatic symptoms) and that Major Neuro-Cognitive psychosis (MNP) is the full blown phenotype of schizophrenia (largely overlapping with deficit schizophrenia). Herein we examined the effects of immune activation in association with tryptophan catabolite (TRYCAT) patterning and memory disorders on PHEMN/DAPS dimensions and MNP.\n\nMethodSerum levels of macrophage inflammatory protein-1 (MIP-1), soluble interleukin (IL)-1 receptor antagonist (sIL-1RA), IL-10, eotaxin, IgA/IgM responses to TRYCATs, and Consortium to Establish a Registry for Alzheimers disease (CERAD) tests were assessed in 40 controls and 80 schizophrenia patients.\n\nResultsSchizophrenia and MNP were predicted by significantly increased levels of IL-10, eotaxin and TRYCATs. A large part of the variance in both PHEMN/DAPS symptom dimensions (42.8%) was explained by cytokine levels and TRYCATs combined. The MTP+sTL-1R A+IL-10 composite score and eotaxin explained each around 19% of the variance in symptom dimensions, and approximately 18% of memory deficits. Moreover, MIP+sIL-1RA+IL-10 was significantly associated with elevations in picolinic acid, xanthurenic acid and 3-OH-kynurenine. Partial Least Squares path modeling shows that the highly significant effects of MIP+sIL-1RA+IL-10 on symptomatology are mediated by the effects of noxious TRYCATs on memory deficits.\n\nConclusionsCurrent findings indicate that in schizophrenia, immune activation may underpin activation of indoleamine-2,3-dioxygenase and kynurenine monooxygenase, while impairments in episodic and semantic memory may be caused by the neurotoxic effects of TRYCATs and eotaxin. The combined effects of immune activation, eotaxin and memory defects determine to a large extent PHEMN/DAPS symptoms and the MNP phenotype. These findings indicate that schizophrenia phenomenology is largely mediated by multiple neuro-immune pathways and that immune activation, increased production of eotaxin and neurotoxic TRYCATs (picolinic acid, xanthurenic acid and 3-HO-kynurenine) are new drug targets in schizophrenia and MNP.

neuroscience↗