Mood Stabilizers and the Influence on Global Leukocyte DNA Methylation in Bipolar Disorder
Lena Backlund,b,d,e,*Ya Bin Wei,b,eLina Martinsson,a,bPhilippe A. Melas,a,eJia Jia Liu,b,e,fNinni Mu,b,eClaes-Göran Östenson,cTomas J. Ekström,a,eMartin Schalling,b,e and Catharina Lavebrattb,e
Little is known about the relationship between treatments for bipolar disorder (BD), their therapeutic responses and the DNA methylation status. We investigated whether global DNA methylation levels differ between healthy controls and bipolar patients under different treatments. Global DNA methylation was measured in leukocyte DNA from bipolar patients under lithium monotherapy (n = 29) or combination therapy (n = 32) and from healthy controls (n = 26). Lithium response was assessed using the Alda scale. Lithium in monotherapy was associated with hypomethylation (F = 4.63, p = 0.036). Lithium + valproate showed a hypermethylated pattern compared to lithium alone (F = 7.27, p = 0.011). Lithium response was not associated with DNA methylation levels. These data suggest that the choice of treatment in BD may lead to different levels of global DNA methylation. However, further research is needed to understand its clinical significance.
My take – In bipolar patients not on medications there could be a global DNA hypomethylation. Whether lithium results in global DNA hypomethylation, there is a pre-existing global DNA hypermethylation in bipolar disorder or both is not clear from this research.
Epigenetic aberrations in leukocytes of patients with schizophrenia: association of global DNA methylation with antipsychotic drug treatment and disease onset
Philippe A. Melas, Maria Rogdaki, Urban Ösby, Martin Schalling, Catharina Lavebratt, Tomas J. Ekström
Even though schizophrenia has a strong hereditary component, departures from simple genetic transmission are prominent. DNA methylation has emerged as an epigenetic explanatory candidate of schizophrenia’s nonmendelian characteristics. To investigate this assumption, we examined genome-wide (global) and gene-specific DNA methylation levels, which are associated with genomic stability and gene expression activity, respectively. Analyses were conducted using DNA from leukocytes of patients with schizophrenia and controls. Global methylation results revealed a highly significant hypomethylation in patients with schizophrenia (P<2.0×10-6) and linear regression among patients generated a model in which antipsychotic treatment and disease onset explained 11% of the global methylation variance (adjusted R2=0.11, ANOVA P>0.001). Specifically, haloperidol was associated with higher (“control-like”) methylation (P=0.001), and early onset (a putative marker of schizophrenia severity) was associated with lower methylation (P=0.002). With regard to the gene-specific methylation analyses, and in accordance with the dopamine hypothesis of psychosis, we found that the analyzed region of S-COMT was hypermethylated in patients with schizophrenia (P=0.004). In summary, these data support the notion of a dysregulated epigenome in schizophrenia, which, at least globally, is more pronounced in early-onset patients and can be partly rescued by antipsychotic medication. In addition, blood DNA-methylation signatures show promise of serving as a schizophrenia biomarker in the future.—Melas, P. A., Rogdaki, M., Ösby, U., Schalling, M., Lavebratt, C., Ekström, T. J. Epigenetic aberrations in leukocytes of patients with schizophrenia: association of global DNA methylation with antipsychotic drug treatment and disease onset. FASEB J. 26, 2712-2718 (2012). www.fasebj.org
Aging as an Epigenetic Phenomenon
Vasily V Ashapkin 1 , Lyudmila I Kutueva 1 , Boris F Vanyushin 1 Affiliations
Introduction: Hypermethylation of genes associated with promoter CpG islands, and hypomethylation of CpG poor genes, repeat sequences, transposable elements and intergenic genome sections occur during aging in mammals. Methylation levels of certain CpG sites display strict correlation to age and could be used as “epigenetic clock” to predict biological age. Multi-substrate deacetylases SIRT1 and SIRT6 affect aging via locus-specific modulations of chromatin structure and activity of multiple regulatory proteins involved in aging. Random errors in DNA methylation and other epigenetic marks during aging increase the transcriptional noise, and thus lead to enhanced phenotypic variation between cells of the same tissue. Such variation could cause progressive organ dysfunction observed in aged individuals. Multiple experimental data show that induction of NF-κB regulated gene sets occurs in various tissues of aged mammals. Upregulation of multiple miRNAs occurs at mid age leading to downregulation of enzymes and regulatory proteins involved in basic cellular functions, such as DNA repair, oxidative phosphorylation, intermediate metabolism, and others.p
Conclusion: Strong evidence shows that all epigenetic systems contribute to the lifespan control in various organisms. Similar to other cell systems, epigenome is prone to gradual degradation due to the genome damage, stressful agents, and other aging factors. But unlike mutations and other kinds of the genome damage, age-related epigenetic changes could be fully or partially reversed to a “young” state.
My take – Increasing activity of TET enzymes could reduce incidences of cancer, slow aging and ameliorate various mental illness, such as schizophrenia. Increasing activity of TET enzymes can be done now.