The role of microRNAs in amyotrophic lateral sclerosis

Dissertação para obtenção do Grau de Mestre em Genética Molecular e Biomedicina

MicroRNAs (miRNAs) are emerging as a primary mediator of gene regulation in many different cell types. There is increasing evidence that specific subsets of miRNA play a prominent role in the nervous system, both in development and in specific neurodegenerative diseases. This study aims to elucidate the role of microRNA in selective motor neuron death that is the hallmark of amyotrophic Lateral sclerosis (ALS). Pre-symptomatic time-point was chosen since the levels of miRNAs are highly likely to be altered as a secondary consequence of cell injury and death in ALS. Laser capture microdissection (LCM) was used to study miRNA profiles in motor neurons of spinal cord tissue from SOD1G93A mice, the best characterized model of ALS. In preliminary work, using miRNA specific chips we have identified 2 miRNAs which are dramatically upregulated before disease onset. In this study, high RNA quality was achieved from laser captured cells, which consist in a major advance towards obtaining meaningful results of these miRNAs expression in downstream applications. Despite LCM technology has become increasingly sophisticated; rapidly obtaining enough amount of starting material for downstream applications is still extremely challenging. The combination of this optimized technique with microarrays, followed by RT-qPCR may provide insights into potential contribution of microRNAs to progression of neurodegeneration of motor neurons in ALS.