PI: Richard Watt
Co-PI: Jonathan Wisco
The MEG proposal focused on understanding how elevated homocysteine levels cause the inability of cells to control iron levels as a cause for Alzheimer’s disease. Iron is associated with the amyloid plaques and tau tangles that are proposed to cause damage to neurons. Dr. Wisco and I previously submitted an NIH R15 proposal that was viewed positively but was not funded due to a lack of preliminary data. Our goal was to use MEG funding to provide preliminary data supporting the hypothesis. We proposed that Homocysteine was a dangerous trigger for disrupting iron metabolism.
Biochemical techniques, immunohistochemistry techniques and MRI were used in animal models and cell culture models to test the hypothesis that Homocysteine disrupted iron metabolism and leads to accumulation in amyloid plaques and tau tangles. The starting of the mice colony took awhile to get started so many of the results are still in process of being obtained. We are currently studying the 6 month mice of a 1 year experiment.
Evaluation of how well the academic objectives of the proposal were met and Description of the results/findings of the project.
Aim #1 – Homocysteine triggers inflammation and disrupts iron metabolism.
Figure 1 shows Homocysteine triggering inflammation and increases in the Iron Pool based on the increased presence of ferritin.
Initial tests were performed in mice with and without genetic predispositions to express tau, amyloid beta and ApoE. A significant amount of the budget was used to pay for the housing and feeding of these animals. The cohort was raised for 1 year. We are still in the evaluation phase of analyzing the data but we have preliminary data that. Homocysteine does produce pro-inflammatory conditions in cells. ApoE is significantly influenced by homocysteine.
We are in the process of evaluating brains from mice for increased Tau and Amyloid beta after Hcy treatment.
Specific Aim 2: Iron Chelators will Lower the Cytosolic Iron Pools and decrease inflammation.
Cells treated with iron chelators had lower inflammatory response as indicated by activation of inflammatory pathways such as TNF alpha and Stat3 and SMAD. Also the production of matrix metallo proteinase enzymes that activate other inflammatory responses were also lowered with iron chelator treatment.
Aim #3 MRI analysis: MRI was collected on the early stages of mice but these are very early stages for MRI to be useful. Images will be correlated with biochemical analysis as the data is collected. MRI from older mice will be evaluated as the mice age.
Alternatively, iron present in PP-tau tangles or amyloid plaques can be observed and detected using the elemental analysis feature of the TEM called Energy-dispersive X-ray analysis (XEDS). These protein aggregates will be isolated from mice and analyzed.
Evaluation of the mentoring environment – student participation.
Three graduate students were mentored in the Wisco lab and Two graduate students in the Watt lab. Two undergraduate students participated in the Watt lab and Five undergraduate students were mentored in the Wisco lab.
In the future, the two labs will work more to have coordinated lab meetings to do a better job in sharing data and coordinating tasks between the two labs.
Description of how the budget was spent
The budget was spent on:
- Purchasing animals and paying for the cost of care and housing.
- Buying supplies for the analysis, antibodies, immunohistochemistry, other analysis supplies.
- Undergraduate salaries.
Summary: This is still an active and ongoing project but the MEG funding was essential to get it off the ground and running. Thank you.