Mitophagy – keeping brain cells clean and healthy

Neurodegenerative disorders are a group of diseases in which the cells of our central nervous system gradually stop working and die. Among the most well-known are Alzheimer and Parkinson disease that affect millions of people worldwide. During the last 25 years, the incidence of Parkinson Disease has doubled and today the disease affects 2-3% of the world’s population over 65 years of age. Patients with Parkinson have problems with controlling movements, cognition, sleep disorders, depression, etc.

Mitochondria and the process of mitophagy
Often referred to as the powerhouse of our cells, mitochondria are cell organelles that generate the chemical energy needed to power the cell’s functions. The neurons in our brain depend on the mitochondrial function to transmit nerve signals between brain cells and to muscles and to form new neural connections throughout our life.
As mitochondria age and become damaged they are eliminated by a process called mitophagy. If the process of mitophagy is disturbed, damaged mitochondria will build up in the cells and lead to overproduction of toxins that can damage the healthy mitochondria. Once neurons with defective mitophagy cannot meet the energy demands to grow and survive, they will begin to die. This is a characteristic of Parkinson disease.

Several proteins are involved in the mitophagy process and mutations in these proteins are found in patients with Parkinson disease. Two of these are the proteins PINK1 and Parkin who work together to control the process in a so-called signaling pathway.
The PINK1 protein attaches to the membrane of damaged mitochondria and signal Parkin which then brings certain molecules known as ubiquitin molecules to cover the outer membrane of the mitochondria. This “coat” of molecules acts as a signal that starts several processes to keep the toxic elements in the mitochondria from leaking out, and promote the elimination of the mitochondria.

The experiment

In our experiment, we will test the hypothesis that the Parkin protein is essential for the mitophagy process. To test this, we will compare the mitophagy process in cells with normal (known as wild type) Parkin proteins and mutated Parkin proteins. We will follow these steps:

Step 1: We will introduce a plasmid (small DNA molecule) into cells to make them express wild type or mutant Parkin (a mutation found in patients with Parkinson disease) labelled with a protein (named GFP) that emits green fluorescence. This method is called transfection. If the transfection works, our cells will be green when we look at them under a fluorescence microscope.

Step 2: We will induce mitochondrial damage in the cells by using different chemical agents.

Step 3: We will track the process of mitophagy by checking differences in the intensity of green fluorescence in specific areas of the cells where the mitochondria are located. We will take images at different time points that can be used as data in your SRP assignment.

Step 4: We will compare the images from cells expressing wild type and mutant Parkin to address the hypothesis. We will also count the number of green dots in each image to follow the process of mitophagy in time.

Besides the experiment, you will get a chance to interact with young scientists and experience exciting talks about neuro research and about life as a scientist.

Practical information

The experiment will take place at the Biotech Research & Innovation Centre (BRIC), at Ole Maaløesvej 5, 2200 Copenhagen, on 1-2 February 2024

To qualify for the experiment, you need either A-level biology or biotechnology. Please provide documentation in the form of a school statement or transcript.

Participants will be chosen by drawing lots.

Please note that the experiment is meant as an inspiration for your SRP assignment. We do not offer guidance on your SRP after the experiment has ended.

We do not offer help with transportation or accommodation.

Sign up