Honorable Mention Excerpts

Blake Holman

Lake Dallas High School
Teacher: Cynthia Powers


Gene Therapy for Parkinson’s Disease Using Adeno-associated Virus Vectors

Parkinson’s disease (PD) is a degenerative disorder of the central nervous system that gradually causes motor system dysfunction. This dysfunction is the result of the death of dopaminergic neurons in the pars compacta, which is part of the substantia nigra of the midbrain (Pfeiffer 21). While the reasons for the death of the neurons is uncertain, it is most likely a combination of the misfolding and aggregation of proteins and mitochondrial impairment (Pfeiffer 22). A developing method for treating the underlying cause of PD is a form of somatic gene therapy using recombinant adeno-associated virus vectors, known as rAAV vectors (Chtarto et al.)…

…rAAV is used in gene therapy to protect against the long-term degrading of the nigrostriatal pathways. To do this, rAAV must have genes that encode for neurotrophic factors, particularly the glial cell line-derived neurotrophic factor or GDNF (Chtarto et al.). The rAAV expressing GDNF is injected into the bilateral putamen and substantia nigra, and the dopaminergic neurons stop the degradation of the nigrostriatal pathways and promote nervous tissue growth, causing recovery even when a significant amount of the neurons are dysfunctional. In one trial, there was a 25-36% increase in motor function as described by the unified Parkinson’s disease rating scale, known as UPDRS (Muramatsu)…<

…The problem with the blood brain barrier has recently been addressed by a new application of sonogram technology. A focused ultrasound can be used to oscillate given microbubbles to allow large molecules through the blood brain barrier. In fact, neurotrophic factors were able to be passed through with relative ease, with much less invasiveness (Wang et al.)…