Transcriptional control of a-synuclein and the engrailed genes as risk factor for Parkinsons's desease

• Applicant: Dr. Horst Simon
• Subject Area: Molecular Biology and Physiology of Neurons and Glial Cells
• Term: from 2006 to 2007
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 25985342

Parkinson s disease (PD) is a multi-system neurodegenerative disorder affecting approximately 1% of the human population older than 65 years. Its hallmark is the slow progressive degeneration of dopaminergic neurons in the substantia nigra leading to dopamine deficiency in the caudate putamen and to a debilitating decrease in motor performance. A main feature of PD is the presence of cytoplasmic inclusions, called Lewy Bodies, in postmorten brains. One major component of Lewy Bodies is aggregated ¿-synuclein. The discovery of point mutations in the coding region and triplication of the ¿-synuclein gene as prevalence factors for PD suggests that its protein structure and/or its expression level play an important role in the molecular etiology of the disease. We recently demonstrated that two homeodomain transcription factors, engrailed-1 and engrailed-2, participate in the transcriptional regulation of ¿-synuclein and play an essential role for the survival of nigral dopaminergic neurons. Both expression of ¿-synuclein as well as the survival of the neurons are controlled in a gene dose dependent manner suggesting a tight control of the engrailed expression may be essential for the maintenance of the cells. In order to test this hypothesis, we propose to analyze the ¿-synuclein promoter for engrailed binding sites and transcriptional activity using cell culture approaches, luciferase assays and electrophoretic mobility shift assays. Furthermore, we will sequences the entire engrailed-1 and -2 loci of a small pool of PD patients (<20) and analyze them for nucleotide variations. We will combine the variations identified by our sequencing effort with SNP information retrieved from public databases. This data set will be then employed for allele discrimination assays, in order to evaluate whether these nucleotide variations are sufficient to discriminate Parkinson¿s patients with high precision from healthy individuals. To achieve this, we will develop 5¿ nuclease PCR assay for each nucleotide variation and use the assays on a larger pool of DNA samples (>200), this time including DNA from control individuals.

• DFG Programme: Research Grants