Submitted by John Casida on
Environmentally induced Parkinson’s disease (PD) is associated with the use of benomyl fungicide, based on epidemiological studies in California farm workers and cell and zebra fish models. A benomyl metabolite inhibits aldehyde dehydrogenase (ALDH) leading to a build-up of its substrate dihydroxyphenylacetaldehyde (DOPAL), the actual toxicant initiating neurodegeneration. There is an urgent need for a mouse model to verify and further examine the relationship between pesticides and PD. Measurement of DOPAL and the corresponding acid (DOPAC) found within a tissue determines the localized activity levels of ALDH. This project seeks to develop a mouse model based on inhibition of ALDH and accumulation of DOPAL in mouse brain striatum after intraperitoneal treatment in vivo with ALDH-inhibiting compounds and other chemicals that either increase or decrease the level of dopamine and DOPAL. Striatum will be collected for analysis via HPLC by a collaborating laboratory. The ratio of dopamine, DOPAL and DOPAC within a tissue can be used to determine the degree of disruption of dopaminergic neurons leading to PD. The activity of ALDH can easily be measured in liver tissues; however, these assays do not easily translate to use with brain tissue and measurement of ALDH against a multitude of substrates or in the presence of an inhibitor. This project will define methods for mouse brain ALDH2 activity assay and determining the role of multiple pesticides as contributors to environmental ALDH inhibition and PD.
Students will assist in mouse studies by preforming intraperitoneal injections, sacrificing mice, dissecting brain tissue, preparing tissue for shipment and HPLC analysis. Students will also work to develop and refine an enzyme assay with increased sensitivity to measure striatal ALDH activity levels against various aldehyde substrates and with both in vivo and in vitro ALDH inhibitors.
Past or concurrent coursework in organismal biology, organic chemistry and biochemistry required; additional coursework in toxicology and lab experience with animals preferred but not required.