Transcriptional correlates of the pathological phenotype in a Huntington’s disease mouse model

Huntington disease (HD) is a fatal neurodegenerative disorder without a cure that is caused by an aberrant expansion of CAG repeats in exon 1 of the huntingtin (HTT) gene. Although a negative correlation between the number of CAG repeats and the age of disease onset is established, additional factors may contribute to the high heterogeneity of the complex manifestation of symptoms among patients. This variability is also observed in mouse models, even under controlled genetic and environmental conditions. To better understand this phenomenon, we analysed the R6/1 strain in search of potential correlates between pathological motor/cognitive phenotypical traits and transcriptional alterations. HD-related genes (e.g., Penk, Plk5, Itpka), despite being downregulated across the examined brain areas (the prefrontal cortex, striatum, hippocampus and cerebellum), exhibited tissue-specific correlations with particular phenotypical traits that were attributable to the contribution of the brain region to that trait (e.g., striatum and rotarod performance, cerebellum and feet clasping). Focusing on the striatum, we determined that the transcriptional dysregulation associated with HD was partially exacerbated in mice that showed poor overall phenotypical scores, especially in genes with relevant roles in striatal functioning (e.g., Pde10a, Drd1, Drd2, Ppp1r1b). However, we also observed transcripts associated with relatively better outcomes, such as Nfya (CCAAT-binding transcription factor NF-Y subunit A) plus others related to neuronal development, apoptosis and differentiation. In this study, we demonstrated that altered brain transcription can be related to the manifestation of HD-like symptoms in mouse models and that this can be extrapolated to the highly heterogeneous population of HD patients

Biofluid Biomarkers in Huntington's Disease

Huntington's disease (HD) is a chronic progressive neurodegenerative condition where new markers of disease progression are needed. So far no disease-modifying interventions have been found, and few interventions have been proven to alleviate symptoms. This may be partially explained by the lack of reliable indicators of disease severity, progression, and phenotype.Biofluid biomarkers may bring advantages in addition to clinical measures, such as reliability, reproducibility, price, accuracy, and direct quantification of pathobiological processes at the molecular level; and in addition to empowering clinical trials, they have the potential to generate useful hypotheses for new drug development.In this chapter we review biofluid biomarker reports in HD, emphasizing those we feel are likely to be closest to clinical applicability

Fibroblasts from patients with major depressive disorder show distinct transcriptional response to metabolic stressors

Major depressive disorder (MDD) is increasingly viewed as interplay of environmental stressors and genetic predisposition, and recent data suggest that the disease affects not only the brain, but the entire body. As a result, we aimed at determining whether patients with major depression have aberrant molecular responses to stress in peripheral tissues. We examined the effects of two metabolic stressors, galactose (GAL) or reduced lipids (RL), on the transcriptome and miRNome of human fibroblasts from 16 pairs of patients with MDD and matched healthy controls (CNTR). Our results demonstrate that both MDD and CNTR fibroblasts had a robust molecular response to GAL and RL challenges. Most importantly, a significant part (messenger RNAs (mRNAs): 26-33%; microRNAs (miRNAs): 81-90%) of the molecular response was only observed in MDD, but not in CNTR fibroblasts. The applied metabolic challenges uncovered mRNA and miRNA signatures, identifying responses to each stressor characteristic for the MDD fibroblasts. The distinct responses of MDD fibroblasts to GAL and RL revealed an aberrant engagement of molecular pathways, such as apoptosis, regulation of cell cycle, cell migration, metabolic control and energy production. In conclusion, the metabolic challenges evoked by GAL or RL in dermal fibroblasts exposed adaptive dysfunctions on mRNA and miRNA levels that are characteristic for MDD. This finding underscores the need to challenge biological systems to bring out disease-specific deficits, which otherwise might remain hidden under resting conditions

Transcription, Epigenetics and Ameliorative Strategies in Huntington’s Disease: a Genome-Wide Perspective

ease (HD) is an early event that shapes the brain transcriptome by both the depletion and ectopic activation of gene products that eventually affect survival and neuronal functions. Disrup-tion in the activity of gene expression regulators, such as transcription factors, chromatin-remodeling proteins, and non-coding RNAs, accounts for the expression changes observed in multiple animal and cellular models of HD and in samples from patients. Here, I review the recent advances in the study of HD transcriptional dysregulation and its causes to finally discuss the possible implications in ameliorative strategies from a genome-wide perspective. To date, the use of genome-wide approaches, predominantly based on microar-ray platforms, has been successful in providing an extensive catalog of differentially regulated genes, including biomarkers aimed at monitoring the progress of the pathology. Although still incipient, the introduction of combined next-generation sequencing techniques is enhancing our comprehension of the mechanisms underlying altered transcriptional dysregulation in HD by providing the first genomic landscapes associated with epigenetics and the occupancy of transcription factors. In addition, the use of genome-wide approaches is becoming more and more necessary to evaluate the efficacy and safety of ameliorative strategies and to identify novel mechanisms of amelioration that may help in the improvement of current preclinical therapeutics. Finally, the major conclusions obtain-ed from HD transcriptomics studies have the potential to be extrapolated to other neurodegenerative disorders

Heroin; science and ethics of the new treatment pluralism

As approaches to treating heroin addiction grow in number, their ethics and their meaningful contribution to the science in this field need more careful consideration

Changes in alcohol history taking and management of alcohol dependence by interns at The Royal Adelaide Hospital

ObjectiveThe objective of this study is to determine whether the presence of a drug and alcohol unit and comprehensive medical education have made a difference to the detection and management of alcohol-related problems in a general teaching hospital.MethodsData were obtained from hospital case notes before and after the introduction of the drug and alcohol unit and medical education. Samples of general admissions and admissions with an alcohol diagnosis were obtained. The outcome measures included alcohol history taking, quantification of alcohol consumption and management of alcohol dependence.ResultsIt was found that for the general admission sample, interns were more likely to take an alcohol history, both in the accident and emergency (A&E) department and on the ward, in 1994 compared to 1988. The difference in the A&E department was statistically significant (P = 0.009). In the A&E department in 1994 there was a greater prevalence of alcohol history taking for male patients (odds ratio (OR) 10.09, 95% confidence interval (CI) 1.89 to 53.70, P = 0.007) compared with female patients (OR = 1.81, 95% CI 0.38 to 8.57, P = 0.045). There were no differences in alcohol history taking by interns in the samples of alcohol-related admissions. There were no statistically significant differences in the prevalence of documenting alcohol histories quantitatively in either sample. The use of alcohol withdrawal charts, ordering diazepam for alcohol withdrawal and ordering drugs which conformed to the hospital formulary all increased significantly by 1994. The prevalence of ordering thiamine and consulting the drug and alcohol unit both decreased slightly by 1994, but not significantly.ConclusionImprovements have been found in the detection and management of alcohol use since the introduction of the Drug and Alcohol Unit and medical education, but there is still room for further improvement and particular areas where greater attention is needed are identified.Matt Gaughwin, Jane Dodding, Jason M White, Philip Rya