Rejuvenation

Rejuvenation is the procedure of reversing the aging process, thus regaining youth. As people get older, their health worsens, strength and intelligence diminishes, beauty goes away. Historically, people in all societies have looked for a way to regain the qualities of youth.

Historical and Cultural Background

Various myths tell the stories about the quest for rejuvenation. It was believed that magic or intervention of a supernatural power can bring back the youth and many mythical adventurers set out on a journey to do that, for themselves, their relatives or some authority that sent them.

In some religions people were to be rejuvenated after death prior to placing them in heaven.

The stories continued well into the 16th century. A famous Spanish explorer Juan Ponce de León led the expedition around the Caribbean islands and into Florida to find the Fountain of Youth. Led by the rumours, the expedition continued the search and many perished. The Fountain was nowhere to be found as locals were unaware of its exact location.

Since the emergence of philosophy, sages and self-proclaimed wizards always made enormous efforts to find the secret of youth, both for themselves and for their noble patrons and sponsors. It was widely believed that some potions may restore the youth.

Another commonly cited approach was attempting to transfer the essence of youth from young people to old. Some examples of this approach were sleeping with virgins or children (sometimes literally sleeping, not necessarily having sex), drinking their blood.

The quest for rejuvenation reached its height with Alchemy. All around the Europe and also beyond alchemists were looking for the Philosopher's Stone, the mythical substance that, as it was believed, could not only turn lead into gold, but also prolong life and restore youth. Although the set goal was not achieved, Alchemy paved the way to the scientific method and so to the medical advances of today.

In fiction, there is an increasing amount of work being done on possibilities of rejuvenation treatments, and the effect this would have on society. Misspent Youth as well as the commonwealth saga by Peter F Hamilton are one of the most well known examples of this, dealing with the short and long term effects of a near perfect 80 yr old to 20 yr old body change with mind intact. Also the Mars trilogy deals with a much more inperfect type of rejuvenation, including problems such as long term memory loss and sheer boredom that comes with such age. Also the post mortal characters in the Revelation Space series often illustrate this issue with long term or essentially infinite lifespans, sheer boredom unduces them to undertake activities of extreme risk.

Modern developments

According to modern science, there are no natural laws preventing successful rejuvenation. Aging is an accumulation of damage to macromolecules, cells, tissues and organs. If any of that damage can be repaired, the result is rejuvenation.

There have been many experiments which have been shown to increase the maximum life span of laboratory animals, thereby achieving life extension. A few experimental methods have had limited success in partially rejuvenating laboratory animals and humans, such as replacing hormones to youthful levels.

Yet another option involves cosmetic changes to the individual to create the appearance of youth. Cosmetic surgery is a large industry offering treatments such as removal of wrinkles ("face lift"), removal of extra fat (liposuction) and reshaping or augmentation of various body parts (abdomen, breasts, face). There are also, as always in history, many fake rejuvenation products that do not work.

The leading modern exponent of scientific rejuvenation is the modern biomedical gerontologist Dr. Aubrey de Grey. He calls his project to reverse the damage we call aging SENS (Strategies for Engineered Negligible Senescence). He has proposed seven strategies for the "seven deadly sins":

1. Cell loss can be repaired (reversed) just by suitable exercise in the case of muscle. For other tissues it needs various growth factors to stimulate cell division, or in some cases it needs stem cells.
2. Senescent cells, can be removed by activating the immune system against them. Or they can be destroyed by gene therapy to introduce "suicide genes" that only kill senescent cells.
3. Protein cross-linking can largely be reversed by drugs that break the links. But to break some of the cross-links we may need to develop enzymatic methods.
4. Extracellular garbage (like amyloid) can be eliminated by vaccination that gets immune cells to "eat" the garbage.
5. For intracellular junk we need to introduce new enzymes, possibly enzymes from soil bacteria, that can degrade the junk (lipofuscin) that our own natural enzymes cannot degrade.
6. For mitochondrial mutations the plan is not to repair them but to prevent harm from the mutations by putting suitably modified copies of the mitochondrial genes into the cell nucleus by gene therapy. The mitochondrial DNA experiences a high degree of mutagenic damage because most free radicals are generated in the mitochondria. A copy of the mitochondrial DNA located in the nucleus will be better protected from free radicals, and there will be better DNA repair when damage occurs. All mitochondrial proteins would then be imported into the mitochondria.
7. For cancer (the most lethal consequence of mutations) the strategy is to use gene therapy to delete the genes for telomerase and to eliminate telomerase-independent mechanisms of turning normal cells into "immortal" cancer cells. To compensate for the loss of telomerase in stem cells we would introduce new stem cells every decade or so.

Dr. de Grey has created the Methuselah Mouse Prize, which awards money to researchers who can rejuvenate mice.

Scientific Journal

• Rejuvenation Research Editor: Aubrey de Grey. Publisher: Mary Ann Liebert, Inc. ISSN 1549-1684 - Published Quarterly

See also

• Aubrey de Grey
• Biogerontology
• Biological immortality
• DNA repair
• Engineered negligible senescence
• Facial rejuvenation
• Immortality
• Life extension
• The Methuselah Mouse Prize
• Senescence

External links

• Regenerative Medicine and Rejuvenation
• Strategies for Engineered Negligible Senescence (SENS)