The therapeutic potential of siRNA in gene therapy of neurodegenerative disorders

RNA interference using small inhibitory RNA (siRNA) has become a powerful tool to downregulate mRNA levels by cellular nucleases that become activated when a sequence homology between the siRNA and a respective mRNA molecule is detected. Therefore siRNA can be used to silence genes involved in the pathogenesis of various diseases associated with a known genetic background. As for many neurodegenerative disorders a causative therapy is unavailable, siRNA holds a promising option for the development of novel therapeutic strategies. Here we discuss different siRNA target strategies aiming for an allele-specific degradation of disease-inducing mRNA and we review the literature in the field of siRNA and its application in animal models of neurodegenerative diseases, including Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), Huntington's disease (HD) and spinocerebellar ataxia (SCA1).