Old Blood, Young Blood

Death and taxes. We all age and unless Aubrey de Gray's Strategies for Engineered Negligible Senescence actually do work soon, we're all going to die. As we age, bodily functions begin to break down - memories fade and muscles strain. A recent publication in Nature uncovers another piece of the puzzle of how our cells age.

Thomas Rando and coworkers at the Stanford University School of Medicine uncovered that old muscles can repair themselves if they are provided a source of young blood. To show this, the authors connected the circulatory systems of young and old mice muscles, and provided them either young or old mouse blood. They then measured the ability of the muscle tissues to regenerate after being damaged.

Let's look at the cells in all four possible environments to see what happened. The red and green colors in the images below come from dyes and markers added to the tissue cultures to visualize certain portions of the cells (it's not really important to understand what they are; just look at them qualitatively).

1. Young tissues connected to young tissues.		2. Young tissues connected to old tissues.
3. Old tissues connected to old tissues.		4. Old tissues connected to young tissues.

So one of these is not like the other ones, #3, and that's the sample with no young parts. Important, as seen in #4, old muscle cells can repair themselves when provided with young blood. These observations suggest that there is something in the young blood that helps keep those cells fix themselves. Determining which of the components is responsible for this regeneration is going to be a monumental task since there are thousands and thousands of components in blood. Still, this work shows that the environment of a cell may be as important as the cell itself. But don't hold your breath for a Fountain of Youth just yet, Aubrey.

Via: Eurekalert
Wired covered this here.