“And until recently, I don’t think anybody would have looked. “To my knowledge, no one has connected an Mfn2 mutation to Parkinson’s disease,” Dorn says. How do these self-destruct signals inside the mitochondria communicate with proteins far away in the surrounding cell that orchestrate the actual destruction?” “Scientists would draw the middle part of the chain as a black box. And since 2006, scientists have been working to identify the mysterious middle section of the chain – the part that allows the internal environment of sick mitochondria to communicate to the rest of the cell that it needs to be destroyed. Both the beginning and end of the chain of events are well understood. Over the past 15 years, scientists have described much of this quality-control system. Most of the time, quality-control systems in a healthy cell make sure damaged or dysfunctional mitochondria are identified and removed. This damage eventually can lead to Parkinson’s or heart failure, depending on the organ affected. If bad mitochondria are allowed to build up, not only do they stop making fuel, they begin consuming it and produce molecules that damage the cell. Heart muscle cells and neurons in the brain have huge numbers of mitochondria that must be tightly monitored. “This suggested they are somehow related, and now we have identified a fundamental mechanism that links the two.” “If you have Parkinson’s disease, you have a more than two-fold increased risk of developing heart failure and a 50 percent higher risk of dying from heart failure,” says senior author Gerald W. The new discovery in heart cells provides some explanation for the long known epidemiologic link between Parkinson’s disease and heart failure. The findings are reported April 26 in the journal Science. Working in mouse and fruit fly hearts, the researchers found that a protein known as mitofusin 2 (Mfn2) is the long-sought missing link in the chain of events that control mitochondrial quality. These same molecules implicated in heart failure also play roles in Parkinson’s disease. It also shows signs of failure because it is missing Parkin, another key molecule in mitochondrial quality control. Superimposed on the mouse heart is a fruit fly heart tube, shown in color. Dorn II, MD A mouse heart, in gray, shows signs of heart failure because it is missing Mfn2, newly identified as a key molecule in the process that culls unhealthy mitochondria from cells. And while heart and brain tissue may seem entirely different in form and function, one vital characteristic they share is a massive need for fuel. They manufacture the energy the cell requires to perform its many duties. These cellular power plants are called mitochondria. Understanding how damage to the body’s cellular power plants leads to Parkinson’s disease and, perhaps surprisingly, to some forms of heart failure. Researchers at Washington University School of Medicine in St.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |