The rationale of the proposed work is to establish the importance of a novel mechanism for controlling the production of alpha-synuclein, a causative agent in human Parkinson’s disease. Our exciting preliminary results establish a strong link between the activities of nuclear proteins termed GATA factors and alpha-synuclein expression, potentially representing a landmark breakthough that could lead to new therapeutic targets.
We will test whether GATA-2, which is expressed in dopaminergic neurons, is a critical inducer of alpha-synuclein expression in biologically relevant neuronal cell systems. These studies involve elevating or reducing the amount of GATA-2 and determining how these alterations affect the production of alpha-synuclein. We will also investigate the underlying mechanisms of how GATA-2 affects alpha-synuclein expression. Defining such mechanisms is expected to reveal potential targets for therapeutic modulation.
Relevance to Diagnosis/Treatment of Parkinson’s Disease:
There is a consensus that lowering alpha-synuclein levels will be efficacious for the treatment of Parkinson’s. Thus, defining processes that elevate and sustain alpha-synuclein expression opens up completely new doors for developing novel therapeutic approaches. Furthermore, if the link between GATA-2 and alpha-synuclein expression is rigorously validated in relevant neurons, the level of GATA-2 expression and/or its activity has potential to be an important diagnostic parameter.
We expect to establish the importance of GATA-2 for controlling alpha-synuclein levels in relevant neurons. Rigorously testing the proposed hypotheses will therefore provide the requisite foundation for subsequent translational efforts.
We established an assay in which murine embryonic stem cells are differentiated into primitive erythroid colonies (precursors of red blood cells) or tyrosine hydroxylase-positive dopaminergic neurons. We used this assay to compare the capacity of three genetic variations of GATA-2 ES cells(wild-type, Gata2+/-, and Gata2-/- ) to generate neurons. We found that all three ES cell lines were competent to generate neurons that stained positive for tyrosine hydroxylase, a marker of dopaminergic neurons, and also MAP2, a generic neuronal marker. In these ES cell-derived neuronal cultures, we quantitated expression of alpha-synuclein mRNA and are conducting additional analyses to rigorously establish the contribution of GATA-2 to alpha-synuclein expression in primary neurons derived from ES cells.