There are currently no validated biomarkers which can be used to accurately diagnose Alzheimer's disease (AD) or to distinguish it from other dementia-causing neuropathologies. Moreover, to date, ...only symptomatic treatments exist for this progressive neurodegenerative disorder. In the search for new, more reliable biomarkers and potential therapeutic options, epigenetic modifications have emerged as important players in the pathogenesis of AD. The aim of the article was to provide a brief overview of the current knowledge regarding the role of epigenetics (including mitoepigenetics) in AD, and the possibility of applying these advances for future AD therapy. Extensive research has suggested an important role of DNA methylation and hydroxymethylation, histone posttranslational modifications, and non-coding RNA regulation (with the emphasis on microRNAs) in the course and development of AD. Recent studies also indicated mitochondrial DNA (mtDNA) as an interesting biomarker of AD, since dysfunctions in the mitochondria and lower mtDNA copy number have been associated with AD pathophysiology. The current evidence suggests that epigenetic changes can be successfully detected, not only in the central nervous system, but also in the cerebrospinal fluid and on the periphery, contributing further to their potential as both biomarkers and therapeutic targets in AD.
Theranostic Biomarkers for Schizophrenia Perkovic, Matea Nikolac; Erjavec, Gordana Nedic; Strac, Dubravka Svob ...
International journal of molecular sciences,
04/2017, Letnik:
18, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Schizophrenia is a highly heritable, chronic, severe, disabling neurodevelopmental brain disorder with a heterogeneous genetic and neurobiological background, which is still poorly understood. To ...allow better diagnostic procedures and therapeutic strategies in schizophrenia patients, use of easy accessible biomarkers is suggested. The most frequently used biomarkers in schizophrenia are those associated with the neuroimmune and neuroendocrine system, metabolism, different neurotransmitter systems and neurotrophic factors. However, there are still no validated and reliable biomarkers in clinical use for schizophrenia. This review will address potential biomarkers in schizophrenia. It will discuss biomarkers in schizophrenia and propose the use of specific blood-based panels that will include a set of markers associated with immune processes, metabolic disorders, and neuroendocrine/neurotrophin/neurotransmitter alterations. The combination of different markers, or complex multi-marker panels, might help in the discrimination of patients with different underlying pathologies and in the better classification of the more homogenous groups. Therefore, the development of the diagnostic, prognostic and theranostic biomarkers is an urgent and an unmet need in psychiatry, with the aim of improving diagnosis, therapy monitoring, prediction of treatment outcome and focus on the personal medicine approach in order to improve the quality of life in patients with schizophrenia and decrease health costs worldwide.
Neuroinflammation plays an important role in Alzheimer's disease (AD). During this process, activated microglia release pro-inflammatory cytokines such as interleukin (IL)-1α, IL-1β, IL-6, and tumor ...necrosis factor α (TNFα) that participate in neuron damage, but also anti-inflammatory cytokines (such as IL-10), which maintain homeostasis of immune response. Previous studies showed the association of IL-1α -889C/T (rs1800587), IL-1β-1473G/C (rs1143623), IL-6 -174C/G (rs1800795), IL-10 -1082G/A (rs1800896), and TNFα -308A/G (rs1800629) polymorphisms with AD.
We aimed to investigate whether people with certain IL-1α, IL-1β, IL-6, IL-10, and TNFα genotypes in these polymorphisms are more prone to develop AD-related pathology, reflected by pathological levels of cerebrospinal fluid (CSF) AD biomarkers including amyloid-β1-42, total tau (t-tau), tau phosphorylated at Thr 181 (p-tau181), Ser 199 (p-tau199), and Thr 231 (p-tau231), and visinin-like protein 1 (VILIP-1).
The study included 115 AD patients, 53 patients with mild cognitive impairment, and 11 healthy controls. The polymorphisms were determined using real-time polymerase chain reaction. Levels of CSF biomarkers were determined by enzyme-linked immunosorbent assay.
A significant increase in p-tau CSF levels was found in patients with the AA IL-10 -1082G/A and GG TNFα -308A/G genotypes, and in carriers of a G allele in IL-1β -1473C/G and IL-6 -174C/G polymorphisms. t-tau levels were increased in carriers of a G allele in IL-1β -1473C/G polymorphism. An increase in VILIP-1 levels was observed in patients with CG and GG IL-1β -1473C/G, GC IL-6 -174C/G, and GG TNFα -308A/G genotype.
These results suggest that persons carrying certain genotypes in IL10 (-1082G/A), IL1β (1473C/G), IL6 (-174C/G), and TNFIα (-308A/G) could be more vulnerable to development of neuroinflammation, and consequently of AD.
Antipsychotic drugs target primarily dopaminergic system which makes catechol-O-methyltransferase (COMT) an interesting target in studies searching for treatment response predictors in schizophrenia. ...The study assessed the association of the COMT rs4680 and rs4818 polymorphisms with therapeutic response to olanzapine, risperidone, clozapine or other antipsychotic medication after 8 weeks of monotherapy in patients with schizophrenia. 521 Caucasian patients with schizophrenia received a monotherapy with olanzapine (10-20 mg/day; N = 190), risperidone (3-6 mg/day; N = 99), or clozapine (100-500 mg/day; N = 102). The fourth group (N = 130) consisted of patients receiving haloperidol (3-15 mg/day), fluphenazine (4-25 mg/day) or quetiapine (50-800 mg/day). Treatment response was defined as a 50% reduction from the baseline positive and negative syndrome scale (PANSS) total and subscale scores, but also as an observed percentage reduction from the initial PANSS
total and subscale scores. Carriers of the COMT rs4680 A allele and carriers of the COMT rs4680-rs4818 C-A haplotype block had greater reduction in the PANSS total scores following olanzapine treatment, compared to carriers of the COMT rs4680 GG genotype and other COMT rs4680-rs4818 haplotypes. The COMT rs4680 A allele, and COMT rs4680-rs4818 C-A haplotype, were significantly associated with therapeutic response in patients treated with olanzapine, but not in patients treated with other antipsychotics.
The molecular underpinnings of post-traumatic stress disorder (PTSD) are still unclear due to the complex interactions of genetic, psychological, and environmental factors. Glycosylation is a common ...post-translational modification of proteins, and different pathophysiological states, such as inflammation, autoimmune diseases, and mental disorders including PTSD, show altered N-glycome. Fucosyltransferase 8 (FUT8) is the enzyme that catalyzes the addition of core fucose on glycoproteins, and mutations in the
gene are associated with defects in glycosylation and functional abnormalities. This is the first study that investigated the associations of plasma N-glycan levels with
-related rs6573604, rs11621121, rs10483776, and rs4073416 polymorphisms and their haplotypes in 541 PTSD patients and control participants. The results demonstrated that the rs6573604 T allele was more frequent in the PTSD than in the control participants. Significant associations of plasma N-glycan levels with PTSD and
-related polymorphisms were observed. We also detected associations of rs11621121 and rs10483776 polymorphisms and their haplotypes with plasma levels of specific N-glycan species in both the control and PTSD groups. In carriers of different rs6573604 and rs4073416 genotypes and alleles, differences in plasma N-glycan levels were only found in the control group. These molecular findings suggest a possible regulatory role of
-related polymorphisms in glycosylation, the alternations of which could partially explain the development and clinical manifestation of PTSD.
Abstract Aims The inability of kidneys to prevent urinary protein leakage represents the earliest sign of renal damage in diabetic kidney disease (DKD). Recent data suggest the possible ...nephroprotective role of the dipeptidyl peptidase-4 (DPP-4) inhibitors. We aimed to investigate whether serum DPP-4 activity is associated with urine albumin excretion (UAE) in patients with type 1 diabetes (type 1 DM). Methods DPP-4 activity and UAE measurement were performed in 113 patients with type 1 DM and glomerular filtration rate (GFR) within normal range. They were divided into three groups according to UAE tertiles. Results Worse lipid profile and higher waist circumference were observed in the group with highest DPP-4 activity. Patients within lowest UAE tertile group had lowest DPP-4 activity value (p < 0.001) compared to group within second and third tertile of UAE. DPP-4 activity correlated with systolic blood pressure (ρ = 0.142; p = 0.001), HbA1c (ρ = 0.133; p = 0.013) and UAE (ρ = 0.349; p < 0.001). In the linear regression analysis when DPP-4 activity was adjusted for age, gender, disease duration, HbA1c, waist circumference, the use of ACEI and hypolipemic agents the association remained significant; UAE increased for 8.136 mg/24 h by each increase of DPP-4 activity of 1 U/L (p < 0.008). Conclusion Our results indicate that serum DPP-4 activity is associated with albuminuria in type 1 diabetes. This arises the question whether the use of DPP-4 inhibitors might serve as an additional therapeutic strategy to prevent proteinuria in patients with DKD.
Monoamine oxidase and agitation in psychiatric patients Nikolac Perkovic, Matea; Svob Strac, Dubravka; Nedic Erjavec, Gordana ...
Progress in neuro-psychopharmacology & biological psychiatry,
08/2016, Letnik:
69
Journal Article
Recenzirano
Subjects with schizophrenia or conduct disorder display a lifelong pattern of antisocial, aggressive and violent behavior and agitation. Monoamine oxidase (MAO) is an enzyme involved in the ...degradation of various monoamine neurotransmitters and neuromodulators and therefore has a role in various psychiatric and neurodegenerative disorders and pathological behaviors. Platelet MAO-B activity has been associated with psychopathy- and aggression-related personality traits, while variants of the MAOA and MAOB genes have been associated with diverse clinical phenotypes, including aggressiveness, antisocial problems and violent delinquency. The aim of the study was to evaluate the association of platelet MAO-B activity, MAOB rs1799836 polymorphism and MAOA uVNTR polymorphism with severe agitation in 363 subjects with schizophrenia and conduct disorder. The results demonstrated significant association of severe agitation and smoking, but not diagnosis or age, with platelet MAO-B activity. Higher platelet MAO-B activity was found in subjects with severe agitation compared to non-agitated subjects. Platelet MAO-B activity was not associated with MAOB rs1799836 polymorphism. These results suggested the association between increased platelet MAO-B activity and severe agitation. No significant association was found between severe agitation and MAOA uVNTR or MAOB rs1799836 polymorphism, revealing that these individual polymorphisms in MAO genes are not related to severe agitation in subjects with schizophrenia and conduct disorder. As our study included 363 homogenous Caucasian male subjects, our data showing this negative genetic association will be a useful addition to future meta-analyses.
•MAO and severe agitation were studied in schizophrenia and conduct disorder.•Higher platelet MAO-B activity was found in subjects with severe agitation.•MAOA and MAOB polymorphisms were not significantly associated with severe agitation.•Platelet MAO-B activity was not associated with MAOB rs1799836 polymorphism.•Platelet MAO-B activity was suggested as a peripheral marker of severe agitation.
Schizophrenia, depression and posttraumatic stress disorder (PTSD) are severe mental disorders and complicated diagnostic entities, due to their phenotypic, biological and genetic heterogeneity, ...unknown etiology, and poorly understood alterations in biological pathways and biological mechanisms. Disturbed homeostasis between overproduction of oxidant species, overcoming redox regulation and a lack of cellular antioxidant defenses, resulting in free radical-mediated pathology and subsequent neurotoxicity contributes to development of depression, schizophrenia and PTSD, their heterogeneous clinical presentation and resistance to treatment. Metabolomics is a discipline that combines different strategies with the aim to extract, detect, identify and quantify all metabolites that are present in a biological sample and might provide mechanistic insights into the etiology of various psychiatric disorders. Therefore, oxidative stress research combined with metabolomics might offer a novel approach in dissecting psychiatric disorders, since these data-driven but not necessarily hypothesis-driven methods might identify new targets, molecules and pathways responsible for development of schizophrenia, depression or PTSD. Findings from the oxidative research in psychiatry together with metabolomics data might facilitate development of specific and validated prognostic, therapeutic and clinical biomarkers. These methods might reveal bio-signatures of individual patients, leading to individualized treatment approach. In reviewing findings related to oxidative stress and metabolomics in selected psychiatric disorders, we have highlighted how these novel approaches might make a unique contribution to deeper understanding of psychopathological alterations underlying schizophrenia, depression and PTSD.
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Nowadays depression is considered as a systemic illness with different biological mechanisms involved in its etiology, including inflammatory response, hypothalamic-pituitary-adrenal (HPA) axis ...dysregulation and neurotransmitter and neurotrophic systems imbalance. Novel “omics” approaches, such as metabolomics and glycomics provide information about altered metabolic pathways and metabolites, as well as disturbances in glycosylation processes affected by or causing the development of depression. The clinical diagnosis of depression continues to be established based on the presence of the specific symptoms, but due to its heterogeneous underlying biological background, that differs according to the disease stage, there is an unmet need for treatment response biomarkers which would facilitate the process of appropriate treatment selection. This paper provides an overview of the role of major stress response system, the HPA axis, and its dysregulation in depression, possible involvement of neurotrophins, especially brain-derived neurotrophic factor, glial cell line–derived neurotrophic factor and insulin-like growth factor-1, in the development of depression. Article discusses how activated inflammation processes and increased cytokine levels, as well as disturbed neurotransmitter systems can contribute to different stages of depression and could specific metabolomic and glycomic species be considered as potential biomarkers of depression. The second part of the paper includes the most recent findings about available medical treatment of depression. The described biological factors impose an optimistic conclusion that they could represent easy obtainable biomarkers potentially predicting more personalized treatment and diagnostic options.
•Depression is characterized by elevated levels of stress and proinflammatory factors.•Decreased neurotrophins indicate the pathophysiological processes in depression.•Antidepressants normalize 5-HT neurotransmission which is decreased in depression.•Products of amino and fatty acid metabolisms reflect the pathogenesis of depression.•Increased N-glycan sialyation is associated with the severity of depression.
The noradrenergic and dopaminergic systems are affected in Alzheimer's disease (AD). Polymorphisms in genes encoding enzymes and proteins that are components of these systems can affect products of ...transcription and translation and lead to altered enzymatic activity and alterations in overall dopamine and noradrenaline levels. Catechol-O-methyltransferase (COMT) and monoamine oxidase B (MAOB) are the enzymes that regulate degradation of dopamine, while dopamine β-hydroxylase (DBH) is involved in synthesis of noradrenaline. COMT Val158Met (rs4680), DBH rs1611115 (also called -1021C/T or -970C/T), and MAOB rs1799836 (also called A644G) polymorphisms have been previously associated with AD. We assessed whether these polymorphisms are associated with cerebrospinal fluid (CSF) AD biomarkers including total tau (t-tau), phosphorylated tau proteins (p-tau181, p-tau199, and p-tau231), amyloid-β42 (Aβ42), and visinin-like protein 1 (VILIP-1) to test possible relationships of specific genotypes and pathological levels of CSF AD biomarkers. The study included 233 subjects: 115 AD, 53 mild cognitive impairment, 54 subjects with other primary causes of dementia, and 11 healthy controls. Significant decrease in Aβ42 levels was found in patients with GG compared to AG COMT Val158Met genotype, while t-tau and p-tau181 levels were increased in patients with AA compared to AG COMT Val158Met genotype. Aβ42 levels were also decreased in carriers of A allele in MAO-B rs1799836 polymorphism, while p-tau181 levels were increased in carriers of T allele in DBH rs1611115 polymorphism. These results indicate that COMT Val158Met, DBH rs1611115, and MAOB rs1799836 polymorphisms deserve further investigation as genetic markers of AD.
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