Since 2006, scientists have been able to turn mature cells back to their embryonic state, producing so-called induced pluripotent stem cells (IPS cells), that can be applied in regenerative medicine, since they represent a single source of cells that could be used to replace those lost to damage or disease. Today, a scientist named Izpisúa Belmonte wants to apply the technique to produce an elixir of youth
How does it work?
Here’s how it works: every somatic cell in the body has the same information coded in DNA, it doesn’t matter if it’s a bone cell, brain cell or a liver cell, the DNA is the same. However, despite identical genetic information, cells develop to have different functions, have different morphology and form different tissues and organs.
Transcription factors are the proteins that work as chemical switches in a cell. They determine which of cells genes are turned on and which are off in order to make sure that particular genes are expressed in the right cell at the right time and in the right amount. By erasing these epigenetic marks, cell forgets its identity, and returns to embryonic state, creating IPS cells.
The technique, called ‘reprogramming’, resets an adult cell and ‘rewinds’ its development, to get a stem cell capable then to be developed in any different type of tissue. The technique could be used to generate transplants without the risk of immune rejection, since the organ would consist of cells with patient’s genetic material.
Great, let’s do that and so we all become immortal!
This technique is frequently used by laboratories to manufacture stem cells, however, there are still a lot of unsolved problems. One of them is low efficiency — only 0.01–0.1% of cells are being reprogrammed. The technique also requires tedious genetic manipulations that might compromise the quality of the generated cells. Another serious issue: the technique may trigger cancer-causing genes, causing the development of tumours.
Back in 2006, Shinya Yamanaka, a Japanese Nobel Prize-winning stem cell researcher, generated IPS cells from adult mouse fibroblasts, the most common cells of connective tissue in animals that play crucial role in wound healing. Later he and his team generated IPS cells from human adult fibroblasts by adding four proteins to human adult cells. These proteins, called after the great scientists as Yamanaka factors, function by wiping the epigenetic marks in a cell.
An elixir of youth
Based on the Yamanaka’s findings, Juan Carlos Izpisua Belmonte, a scientists who works at the Gene Expression Laboratory at San Diego’s Salk Institute for Biological Studies, aims to translate reprogramming technologies to encourage regeneration in living animals.
‘Aging is nothing other than molecular aberrations that occur at the cellular level’ says researcher.
According to Izpisúa Belmonte, as we age the accumulation of changes to our epigenetic marks leads to low efficiently in the cells’ function. Scientist thinks the changes could be a cause of the whole aging process. He believes that reversing these epigenetic changes through reprogramming may turn back this process.
Todays experiments of Izpisúa Belmonte’s team are dedicated to find a way to rejuvenate an entire body. Experiments are conducted on mice suffering from progeria, a disease caused by a gene malfunction that leads to aging at a very early age. The reprogramming occurred inside an animal body, not in a Petri dish, however, the experiments were often fatal for mice. By clearing most of the epigenetic footprints, cell ‘forgets’ its function and the patient dies.
In 2016, after series of unsuccessful experiments, the researcher tried to expose mice to a less lethal reprogramming procedure, while giving them limited doses of antibiotics. It gave quite the results: treated mice became more physically robust and lived 30% longer than their mates.
There are still a lot of questions about the study. The scientific community has been definitely intrigued by IzpisúaBelmonte’s experiments, however, the researcher hasn’t yet applied the technics on normal mice, only on those suffering from progeria. A next step would be to try to apply it to the human body, which is quite different.
Still Izpisúa Belmonte is being quite an optimistic realist: ‘I think the kid that will be living to 130 is already with us. He has already been born. I’m convinced.’
We’ Intrigued: who wouldn’t want to live for up to 130 years?Christina Daumann