Fight Aging!

Over at the Scientist, you'll find an interesting researcher's perspective on a topic that's come up here a couple of times: the relationship between the mechanics of cell division, garbage management, and aging. In essence we might look back at the origins of cellular life and decide that aging was in some way an inevitable adaptation in bacteria and other single celled life, stemming from the need to manage their garbage load. A cell, after all, accumulates garbage in the form of malformed proteins and gunk that cannot be broken down. If allowed to build up indefinitely, that garbage will destroy the cell. In order to preserve a lineage, cells therefore practice garbage management when they divide: one daughter cell is given all the garbage, allowing the other to continue pristine.

This works out well for single celled organisms - after all, they can just write off the occasional daughter lineage turned into a garbage disposal mechanism. It isn't so helpful for the multi-cellular organisms that later evolved. Now the garbage-cluttered cells can't just be written off: they're still present in the organism, being broken, inefficient, and gradually messing up the cellular environment. The ugly realities of cellular garbage gives rise to the garbage catastrophe in aging, and related issues, such as the age-related failure of garbage recycling mechanisms that have evolved to deal with multi-cellular existence.

The bigger picture is far more complex and less certain than the simple outline I provide, of course, so you might look back into the Fight Aging! archives for a longer introduction.

• The Relevance of Bacterial Aging
• Aubrey de Grey on Bacterial Aging
• The Deep Roots of Aging

And here's that article from the Scientist, which ranges from personal account to speculation on information theory applied to cell biology to outline of aging research:

Unicellular organisms were thought to be capable of dividing forever, as long as conditions allowed: one generation begetting the next down through time - a sort of immortality. If unicellular organisms were like somatic cells, then they would age as they divide, reach the Hayflick limit, and die. It wasn't until the 1950s that researchers who thought about aging began to change their minds. It became clear that the daughter cells of some unicellular organisms seemed to rejuvenate, to start from scratch, while the mother cells accumulated the cellular aberrations that signaled aging. This pattern of aging was seen in such evolutionarily distant organisms like Saccharomyces cerevisiae, known as budding or baker’s yeast, and bacteria such as Caulobacter crescentus and Escherichia coli.

...

For me, that realization begged a more fundamental question, one that as biologists, we are scarcely allowed to ponder: Why do cells allow some mistakes to accumulate? If evolution is such a powerful process - one that finds solutions to all manner of problems - how could there be processes or problems that can’t be fixed? As I continued my research into aging and cell division, I couldn't help but think about how to categorize these "unfixable" problems like aging. Could there be a mathematical description that might capture and explain biology's fallibility?

Read the whole thing; it's an interesting line of thought.