Sequence-Specific Biosensors Report Drug-Induced Changes in Epigenetic Silencing in Living Cells

Treatment with demethylating drugs can induce demethylation and reactivation of abnormally silenced tumor suppressor genes in cancer cells, but it can also induce potentially deleterious loss of methylation of repetitive elements. To enable the observation of unwanted drug effects related to loss of methylation of repetitive DNA, we have developed a novel biosensor capable of reporting changes in DNA accessibility via luminescence, in living cells. The biosensor design comprises two independent modules, each with a polydactyl zinc finger domain fused to a half intein and to a split-luciferase domain that can be joined by conditional protein splicing after binding to adjacent DNA targets. We show that an artificial zinc finger design specifically targeting DNA sequences near the promoter region of the L1PA2 subfamily of Line-1 retroelements is able to generate luminescent signals, reporting loss of epigenetic silencing and increased DNA accessibility of retroelements in human cells treated with the demethylating drugs decitabine or 5-azacytidine

Acceleration of the DNA methylation clock among lynch syndrome‑associated mutation carriers

The research leading to these results has received funding from "la Caixa" Foundation (Ref: CAIXA2017/1) for library preparation, sequencing, and employment of research personnel, from The Fundacion Progreso y Salud, Junta de Andalucia, Spain and from DPI2017-84439-R of MINECO, Madrid and FEDER for sequencing and employment of research personnel. Finally, grant ref. A-BIO-470-UGR20 from University of Granada and FEDER has funded article processing charges (APC) and sample processing expenses.Background: DNA methylation (DNAm) age metrics have been widely accepted as an epigenetic biomarker for biological aging and disease. The purpose of this study is to assess whether or not individuals carrying Lynch Syndromeassociated mutations are affected in their rate of biological aging, as measured by the epigenetic clock. Methods: Genome-wide bisulfite DNA sequencing data were generated using DNA from CD4 + T-cells obtained from peripheral blood using 27 patient samples from Lynch syndrome families. Horvath’s DNAm age model based on penalized linear regression was applied to estimate DNAm age from patient samples with distinct clinical and genetic characteristics to investigate cancer mutation-related aging effects. Results: Both Lynch mutation carriers and controls exhibited high variability in their estimated DNAm age, but regression analysis showed steeper slope for the Lynch mutation carriers. Remarkably, six Lynch Syndrome-associated mutation carriers showed a strong correlation to the control group, and two sisters carrying Lynch Syndrome-associated mutations, with no significant difference in lifestyle and similar chronological age, were assigned very different DNAm age. Conclusions: Future studies will be required to explore, in larger patient populations, whether specific epigenetic age acceleration is predictive of time-to-cancer development, treatment response, and survival. Epigenetic clock DNAm metrics may be affected by the presence of cancer mutations in the germline, and thus show promise of potential clinical utility for stratified surveillance strategies based on the relative risk for imminent emergence of tumor lesions in otherwise healthy Lynch Syndrome-associated mutation carriers.La Caixa Foundation CAIXA2017/1Junta de AndaluciaSpanish Government DPI2017-84439-REuropean CommissionUniversity of Granada A-BIO-470-UGR2

Ethanol and Cognition: Indirect Effects, Neurotoxicity and Neuroprotection: A Review

Ethanol affects cognition in a number of ways. Indirect effects include intoxication, withdrawal, brain trauma, central nervous system infection, hypoglycemia, hepatic failure, and Marchiafava-Bignami disease. Nutritional deficiency can cause pellagra and Wernicke-Korsakoff disorder. Additionally, ethanol is a direct neurotoxin and in sufficient dosage can cause lasting dementia. However, ethanol also has neuroprotectant properties and in low-to-moderate dosage reduces the risk of dementia, including Alzheimer type. In fetuses ethanol is teratogenic, and whether there exists a safe dose during pregnancy is uncertain and controversial

Detection of DNA copy number alterations using penalized least squares regression

doi:10.1093/bioinformatics/bti64