October 28, 2021

I, Science

The science magazine of Imperial College

What would you give to stay alive longer? Think about it quickly, the telemere clock is ticking ...

The Business of Immortality

Everlasting life is a concept that we all at some stage have pondered. The creative human mind has found ways to cope with the frightening prospect of mortality since ancient times and the value of living forever is, for many, immeasurable. But what if we were to put a price on it? How much would you be willing to pay to live forever?

Achieving immortality or a ‘cure’ for old age is an enormous driver for business. In 2006, news coverage of the apparently revolutionary drug Resveratrol (which is derived from Japanese Knotweed) prompted enormous sales of the compound, despite the absence of evidence that it actually extends human lifespan. Today, serious attempts are being made by scientists to freeze the bodies of humans to preserve life, or even upload the human mind onto a computer.

The Philosopher’s stone

High and occasionally outlandish expenditure on attempts to either scientifically or religiously extend life is by no means modern. As far back as the 3rd century, Greek writings by Zosimos of Panopolis mention the search for the Philosopher’s stone (named then as Cheirokmeta). It was thought the stone could revive dead plants and create homunculi (a homunculus is a small clone of yourself, a bit like Mini-Me). Throughout the Middle Ages, Renaissance and Early Modern Period, alchemists obsessed desperately in their workshops, working harsh chemistry with metal compounds to extract or create the priceless stone and for many, the fruitless search was life-long.

Ancient Egypt’s Immortals

Possibly the most magnificent symbol of the lengths to which humans are willing to go to for immortality are the great pyramids of Egypt. For the Egyptians, preservation of the body following death was the key to everlasting life. Egyptian culture was heavily based around the river Nile; it was believed that death was in fact a journey across the Nile, from life on the east to everlasting afterlife on the western bank.

Upon coming into power, a new Pharaoh would immediately secure the mines needed to generate the millions of tons of stone that would be used for his pyramidal tomb. Pyramid Khufu for example, was built of 2.3 million stone blocks averaging 3.5 tons each. These colossal structures demonstrate the Egyptian king’s enormous dedication to generating wealth and coordinating a workforce in order to secure his immortal afterlife.

The process of Egyptian mummification was a skilful art. Following the death of Pharaoh Ramses the Great, a 70-day process began in which the corpse was carefully prepared for the afterlife by the high priest Anubis. It was cleansed, purified and dried. The brain was removed by inserting a hook up the nose, and the internal organs were extracted via a slit in the side of the torso. The body was stuffed with herbs, spices and salts then left to dry. The process was highly ritualistic, steeped in prayers and special perfumes were anointed upon the mummy.

Today, most of the pyramids lie in ruin. The mummies themselves are cared for by the Egyptian government. Ramses the Great, for example, is preserved in a glass box in Cairo Museum surrounded by inert gases that will protect his body from further decay.

So what actually happens when we age?

Essentially, over time the body accumulates damage, which causes our body to physiologically malfunction. Not only this, but a ticking ‘molecular clock’ in the body actually causes a cell to signal to itself to die when the body ages. The damage we accumulate, coupled with our altered cellular program leads to a multitude of age-related diseases, such as pulmonary fibrosis, cirrhosis and type two diabetes. As our cells age, they secrete pro-inflammatory and pro-tumorigenic factorsthat increase the likelihood of impaired immune function and certain cancers.

The telomere clock is ticking

Our DNA is linear, and every time the cell divides some DNA is lost from the end of the chromosome because of the way DNA polymerase – the enzyme used to replicate DNA – functions. Without special protection, the telomeres shorten, fray and break. This is known as ‘telomere attrition’ and occurs when the telomeres lose the structure that protects the ends of chromosomes, which causes the chromosome ends to become sticky and fuse to one another leading to genomic instability and gene misregulation.

In some cells the telomeres are regenerated every cell cycle by the enzyme telomerase but the vast majority of human somatic cells do not have this enzyme. This is central to ageing: with every cell division, our chromosomes become a bit shorter and a bit more vulnerable, if the division isn’t accompanied by telomerase activity.

Telomerase, therefore, must be the secret of long live and a way for some plucky scientist to make their fortune, but the enzyme can also be problematic. Over 80% of cancers rely on reactivated telomerase in order to immortalise themselves and divide indefinitely so the lack of telomerase in the majority probably protects against cancer.

Despite the cancer risk, laboratories are looking for ways to supply our telomeres with exactly what they need to prevent damage and shortening, without making them malignantly immortalised. Studying long-lived animals such as the naked mole rat could solve the telomerase conundrum and unlock a multi-billion pound industry in lengthening life.

Cryonics: freeze your body and save it for later

The concept of cryonics is simple: preserve the human body at temperatures of -192°C so that it exists in frozen suspended animation. The tissues can be warmed at a later date in the hope that future technology will allow us to bring the cryogenically frozen human back to life.

You pay for membership with the Cryonics organisation then, when your heart stops beating, a team bounces into action, supplying your brain with oxygen, packing your body with ice and filling your circulatory system with heparin to prevent blood clotting. The body cannot be simply frozen, since the ice crystals that form would make mincemeat of body’s cells. Instead, the cryonics team fills the tissues with cryoprotectant: an elusive human antifreeze which apparently protects cells from the freezing process. The result is then placed in dry ice to cool and, finally, into liquid nitrogen at -192°C.

The cryonics institute is making a lot of money using this technique. Their website describes how cryonics is incredibly affordable, but at a minimal cost of $150, 000, many would beg to differ. In a fun twist, you can pay a meagre $50,000 to have only your head preserved in this way.

So does cryonics actually work? The addition of cryoprotectant to cells has an untested effect, but could permanently poison them. Furthermore, there is currently absolutely no technology that can bring a dead, frozen organism back to life.

Image: Monochrome from Wikipedia.com