Miron's Weblog

[ I’ve started this article 2 years ago – will post it now even though I feel it is incomplete. ]

I’d like to propose a somewhat simplified approach to eliminate aging, given early-stage molecular robots and following the SENS approach to aging.

Results in this approach depend on equal amounts of creation of new cells and destruction of old cells to exponentially reduce the amount of aging related defects in the body over time.

Aubrey de Grey proposes 7 mechanisms for aging, which are believed to be comprehensive:

• Cell loss and atrophy
• Nuclear mutations
• Mitochondria mutations
• Death resistant cells
• Extracellular crosslinks
• Extracellular junk
• Intracellular junk

My proposal is to construct three different molecular machines, that perform the following functions:

• A robot (the Checker) that randomly enters cells and mitochondria, checksums the chromosomes and induces cell death if any mutations are detected. If no mutations are detected, the telomeres are restored to full length.
• A second robot (the Remover) that randomly engulfs small ( 2 – 8 ) clusters of cells and removes them from the body. This is very similar to a Phagocyte, but is indiscriminant.
• A third robot (the Renewer) that induces replication where there is a shortage of cells – probably using some kind of stem cell therapy.

These are engineering tasks and may be possible with early-stage molecular engineering.

One might object to the indiscriminant removal of cells by the Remover. However, the body is able to recover from microscopic injury. Random removal of cells reduces the absolute amount of junk, while allowing the body to regenerate to replace the removed cells.

A crucial aspect of the Remover is that it actually removes the entire material engulfed (except for regular water) from the body, e.g. through urine. This means that we don’t have to design ways to break down different proteins and structures – we’ll just physically remove them from the body.

We also don’t bother correcting DNA. We just destroy the mutated cells and depend on non-mutated cells to take their place.

Here are the 7 mechanisms, and how each is addressed:

• Cell loss and atrophy – addressed by the Renewer
• Nuclear & Mitochondrial mutations – addressed by the Checker – mutated cells and mitochondria are destroyed
• Death resistant cells – Remover will exponentially eliminate these
• Extracellular crosslinks, and intra/extracellular junk – addressed by the Remover + Renewer

The density of junk (crosslink/intra/extracelluar) is reduced by a factor of 2 when a cell (and its surrounding space) is removed and replaced by a new cell. This is because one cell worth of junk is eliminated.

The density of junk will be reduced exponentially in the body as a whole. For example, if 1% of cells are removed per week, 40% of junk will be eliminated per year and 93% in 5 years. The rate will have to be higher than the rate of junk production.

I believe there are several advantages to this proposal. Penetrating cells, checking DNA, engulfing and elimination are all processes that appear in nature and are relatively simple to engineer. We don’t have to design novel ways to break down junk. Additionally, I think it is better to maintain correct DNA than to just protect against cancer. As mutations increase over time, the rate of production of toxic proteins and junk will increase, thereby limiting longetivity anyway. This is in contrast with WILT.

There are several open questions, including:

• Can the body regenerate on the order of 1% of all cells in a week, given encouragement with the right signals and without side-effects such as inflammation?
• What about nerves/CNS where connectivity matters, and the cells do not normally divide?
• Are there any microscopic structures that may be disrupted by a high rate of cell turnover?
• What percentage of cells have any mutation? If this number is too high, the Checker may have to correct DNA, not only check it.
• What effects do epigenetics have on this design? Do we have to check for epigenetic mutations? It seems so. We will have to create a baseline catalog of valid epigenetic switches, so that we know which one do not require Remover action.
• Mitochondria may be too small to enter with a robot – might have to just randomly retire some fraction of them and create new ones

Even if the complete proposal is made difficult by such issues, the Checker by itself will cure all forms Cancer.

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