Cells in our bodies are like cities. Each town has a postal service that allows various packages containing proteins, fats, and genetic materials to be sent from town to town and within itself. The packages carry important cell parts to places where they are needed. For example, these packages bring proteins to the cell’s surface to release neurotransmitters or keep the muscles moving. Without the postal service, our cells will not be able to function properly. In fact, many diseases are caused by the disruption of this postal service. For example, in the brains of Alzheimer’s disease patients, doctors will find patches of protein fragments called amyloid-beta. These amyloid patches trigger symptoms like inflammation and misfiring of neurons, which we see in Alzheimer’s patients, like memory loss and changes in behaviors.
Now the question is, how did these amyloid patches get there in the first place?
Amyloid beta is created by a protein manufacturing defect in brain cells. Typically, these defective parts will be sent to lysosomes, which are tiny incinerators for stuff that the cell doesn’t want, via the cell postal system. But when the postal system fails and the packages start to cause a backup in the system, the cell may say: “you know what, forget about the lysosome, out of sight, out of mind (pun intended).” So, they start sending these toxic packages by the truckload and dump them outside of the city. As time goes by, the toxic amyloid waste accumulates and starts to interfere with normal brain activities, which may lead to Alzheimer’s disease.
Our lab investigates this postal service and its components. We hope that if we can understand why the postal system fails and how we can fix it, we can alleviate some of the symptoms of Alzheimer’s disease.