Principal Investigator/Program Director (Last, first, middle): Rodriguez, EdgardoAbstractA number of neurological disorders are characterized by the preferential dysfunction and/or loss of specificneuronal cell populations and the mechanisms underlying this cell type specific vulnerability remain poorlyunderstood. It has been proposed that the differential neuronal vulnerability observed in these disorders arisesfrom disruptions in cell type specific gene expression regulatory programs responsible for maintaining thephysiological identity and function of the affected neurons. MicroRNAs (miRNAs) are small, non-coding RNAsinvolved in the regulation of gene expression networks at the posttranscriptional level. Studies, including ours,have implicated altered miRNA expression in the pathogenicity of several neurological disorders. Here, wepropose the development of a novel molecular approach to investigate the role that neural cell type specificchanges in miRNA function play in the pathogenicity of neurological diseases. The approach relies on arecombinant adeno-associated virus (rAAV)-based, Cre recombinase-dependent genetic Flp-excision switch(FLEX switch) that restricts the expression of an ectopically delivered miRNA-binding protein Argonaute-2 toCre expressing cells. We call this approach miFLAGO (miRNA-associated, FLEX switch regulated, AGO2).Experiments in Aim-1 will validate the functionality and reproducibility of miFLEX in the cerebellum of adulttransgenic mice engineered to selectively express Cre recombinase in Purkinje cells. Purkinje cell-specificmiFAGO-miRNA complexes will be isolated and used to build miRNA libraries for high-throughput RNAsequencing analysis.
In Aim -2, we will use miFLAGO to investigate the role that cell type specific changes inmiRNA function play in the pathogenicity of a mouse model of Spinocerebellar ataxia type-1, a polyglutaminedisorder caused by the expansion of a CAG repeat in the ATXN1 gene. The short-term goal of this proposal isto provide the research community with a validated novel molecular tool for the study of cell type specificmiRNA function. Long-term, we aim to fine-tune our understanding of neural cell type specific gene expressionregulatory programs and how they might mediate differential vulnerability in neurological disease, with the goalof identifying novel therapeutic routes.Project Description Page 6
; first; middle): Rodriguez; EdgardoNarrativeThere is an unmet need for molecular tools that can facilitate cell type specific analysis of gene expressionprograms. The proposed studies aim to develop a new method for the analysis of cell type specific miRNAexpression in models of neurological disease. The applicability of this tool will be tested in a mouse model ofSpinocerebellar ataxia type-1; a member of the polyglutamine repeat disease family. The goal of this project isto validate this new approach in order to provide the research community with a new powerful tool for the studyof cell type specific gene expression programs.Public Health Relevance Statement Page 7
