A Complete Shield from a toxic chemical that causes Parkinson’s disease in a mouse model.

Approximately 1.5 million people in the US with about 60,000 new cases per year are afflicted by a fatal disease called Parkinson’s disease. Parkinson’s disease can be treated by using dopamine, the brain chemical produced by the substantia nigra (a brain region that helps regulate movement), but the treatments effectiveness loses over time. In Parkinson’s disease small number of nerve cells in the substantia nigra is dead. However it was found that adding multiple copies of a gene that makes a protective protein prevented a toxic chemical from destroying the substantia nigra. It completely obliterated the toxin that caused Parkinson’s disease. Jeffrey Johnson, a scientist, says that the protective mechanism is initiated by a protein called Nrf2, which is found in both humans and mice. This protein is made by astrocytes which are brain cells that carry nerve signals to convey to the neurons.

The study took place with mice with extra Nrf2 genes and mice dosed with MPTP, which is used as a classic model for Parkinson’s disease that kills neurons in the substantia nigra. Johnson says that the astrocytes, which make the protein Nrf2, attaches to their DNA and turns hundreds of genes, which produce and release proteins, to protect nearby neurons from reactions that can kill cells. In the picture it shows the control (top) where mice only took up MPTP (colour is pale) and the extra Nrf2 with the MPTP where it was completely unharmed by the toxin (bottom).

Johnson says that because Nrf2 also protects brain cells, fatal brain diseases such as Alzheimer’s, ALS (amyotrophic lateral sclerosis, or Lou Gehrig’s disease), and Huntington’s disease may be protected. The next step is to figure out how to fix a sick astrocyte or prevent it from getting sick in the first place before the disease can fully take affect.

Emmanuel Kim (42061403)

Reference:

http://www.waisman.wisc.edu/news/JOHNSON2.HTML