Gene expression in fetal Down syndrome brain as revealed by subtractive hybridization

Birth asphyxia as the major complication in newborns: moving towards improved individual outcomes by prediction, targeted prevention and tailored medical care

Perinatal Asphyxia—oxygen deficit at delivery—can lead to severe hypoxic ischaemic organ damage in newborns followed by a fatal outcome or severe life-long pathologies. The severe insults often cause neurodegenerative diseases, mental retardation and epilepsies. The mild insults lead to so-called “minimal brain-damage disorders” such as attention deficits and hyperactivity, but can also be associated with the development of schizophrenia and life-long functional psychotic syndromes. Asphyxia followed by re-oxygenation can potentially lead to development of several neurodegenerative pathologies, diabetes type 2 and cancer. The task of individual prediction, targeted prevention and personalised treatments before a manifestation of the life-long chronic pathologies usually developed by newborns with asphyxic deficits, should be given the extraordinary priority in neonatology and paediatrics. Socio-economical impacts of educational measures and advanced strategies in development of robust diagnostic approaches targeted at effected molecular pathways, biomarker-candidates and potential drug-targets for tailored treatments are reviewed in the paper.

The abnormal regulation of gene expression in autistic brain tissue

Autism is a pervasive developmental disorder of unknown etiology. It is likely caused by mutations in one or more genes. One approach to understanding the molecular changes that occur in autism is to measure gene expression in post-mortem brain samples from individuals diagnosed with autism. This may be accomplished with techniques such as cDNA microarrays or subtractive hybridization. In general, gene expression is regulated as a function of body region, developmental time, and physiological state. A premise of the approaches we describe is that gene expression is regulated in cells from autistic individuals as a consequence of the disease process. It may be useful to detect such changes in order to identify selective biological markers for autism. Additionally, the abnormal regulation of gene expression may reveal cellular pathways that have been disrupted, suggesting strategies for therapeutic intervention.

Differential display reveals deteriorated mRNA levels of NADH3 (complex I) in cerebellum of patients with Down syndrome

Although gene hunting has been carried out in Down Syndrome (DS) cells, information on expressional differences in DS brain is limited. We have recently described expressional differences in fetal DS brain but cannot assign these findings to "DS per" se or simply to "neurodegeneration". We therefore performed gene hunting in cerebellum of adult patients with DS and Alzheimer's disease (AD) neuropathology, AD and controls. The gene hunting method used was differential display and pools of the individual groups were examined to rule out allelic differences. Differential display revealed the absence of a band, identified by sequencing and gene bank work as matching the NADH3 gene (99.1% identity) in cerebellum of DS patients. Dot blots showed the presence of NADH3 signals in only two out of 7 DS patients. We show at the transcriptional level that a mitochondrial enzyme, the complex I, NADH3, is significantly downregulated in DS cerebellum. This extends previous work on deficiencies of the electron transport chain in platelets of patients with DS.