Genome-wide Association Study of Alcohol Dependence

Identification of genes contributing to alcohol dependence will improve our understanding of the mechanisms underlying this disorder

Design and Development of a qPCR-Based Mitochondrial Analysis Workflow for Medical Laboratories

Mitochondrial DNA (mtDNA) damage is closely associated with typical diseases of aging, such as Alzheimer’s or Parkinson’s disease, and other health conditions, such as infertility. This damage manifests in reduced mitochondrial copy number and deletion mutations in mtDNA. Consequently, the analysis of mitochondrial damage by determining the parameters copy number and deletion ratio using quantitative real-time PCR (qPCR) is of interest for clinical diagnostics. To bring the findings from research into laboratory practice, a suitable and reliable process is needed, which must be thoroughly validated. This process includes the software used for the analysis, which must meet extensive regulatory and process requirements. Existing software does not adequately implement the requirements of laboratories and, in particular, does not provide direct support for the calculation of the aforementioned mtDNA parameters. The paper discusses the development of a new software-based analysis workflow that is designed specifically for laboratories to help with the calculation of mtDNA parameters. The software was developed using the User-Centered Design method and is based on the recently introduced prototype, “PlateFlow”. Initial user tests provide positive feedback. In the future, this workflow could form the basis for validations of mitochondrial tests in medical laboratories

Differential gene regulation in the anterior cingulate cortex and superior temporal cortex in schizophrenia:A molecular network approach

The closely connected anterior cingulate cortex (ACC) and superior temporal cortex (STC) are important for higher cognitive functions. Both brain regions are disturbed in schizophrenia, i.e., functional and structural alterations have been reported. This postmortem investigation in brains from patients with schizophrenia and controls compared gene expression in the left ACC and left STC. Most differentially expressed genes were unique to each brain region, but some clusters of genes were equally dysregulated in both, giving rise to a more general disease-specific pattern of gene regulation. The data was used to construct a molecular network of the genes identically expressed in both regions as primary nodes and the metabolically connected genes as secondary nodes. The network analysis identified downregulated clusters of immune-associated gene products and upregulated clusters belonging to the ubiquitin-proteasome system. These findings could help to identify new potential therapeutic targets for future approaches. (c) 2021 Elsevier B.V. All rights reserved

Regulation of immune-modulatory genes in left superior temporal cortex of schizophrenia patients: A genome-wide microarray study

Objectives. The role of neuroinflammation in schizophrenia has been an issue for long time. There are reports supporting the hypothesis of ongoing inflammation and others denying it. This may be partly ascribed to the origin of the materials (CSF, blood, brain tissue) or to the genes selected for the respective studies. Moreover, in some locations, inflammatory genes may be up-regulated, others may be down-regulated. Methods. Genome-wide microarrays have been used for expression profiling in post-mortem brains of schizophrenia patients. Array data have been analyzed by gene set enrichment analysis (GSEA) and further confirmed with selected genes by real-time PCR. Results. In Brodman Area 22 of left superior temporal cortex, at least 70 genes (19%) out of 369 down-regulated genes (P < 0.05) belonged to the immune system. 23 from those 70 genes were randomly selected for real-time PCR. Six reached significance level at P < 0.05. Conclusions. The present data support a brain-specific vie

Effects of the circadian rhythm gene period 1 (Per1) on psychosocial stress-Induced alcohol drinking

Objective: Circadian and stress-response systems mediate environmental changes that affect alcohol drinking. Psychosocial stress is an environmental risk factor for alcohol abuse. Circadian rhythm gene period 1 (Per1) is targeted by stress hormones and is transcriptionally activated in corticotropin releasing factor-expressing cells. The authors hypothesized that Per1 is involved in integrating stress response and circadian rhythmicity and explored its relevance to alcohol drinking.Method: In mice, the effects of stress on ethanol intake in mPer1-mutant and wild-type mice were assessed. In humans, single nucleotide polymorphisms (SNPs) in hPer1 were tested for association with alcohol drinking behavior in 273 adolescents and an adult case-control sample of 1,006 alcohol-dependent patients and 1,178 comparison subjects. In vitro experiments were conducted to measure genotype-specific expression and transcription factor binding to hPer1.Results: The mPer1-mutant mice showed enhanced alcohol consumption in response to social defeat stress relative to their wild-type littermates. An association with the frequency of heavy drinking in adolescents with the hPer1 promoter SNP rs3027172 and with psychosocial adversity was found. There was significant interaction between the rs3027172 genotype and psychosocial adversity on this drinking measure. In a confirmatory analysis, association of hPer1 rs3027172 with alcohol dependence was shown. Cortisol- induced transcriptional activation of hPer1 was reduced in human B- lymphoblastoid cells carrying the risk genotype of rs3027172. Binding affinity of the transcription factor Snail1 to the risk allele of the hPer1 SNP rs3027172 was also reduced.Conclusions: The findings indicate that the hPer1 gene regulates alcohol drinking behavior during stressful conditions and provide evidence for underlying neurobiological mechanisms