Daily Question: How far are human beings from immortality?
Recently, a study that can slow down aging has been released:
Scientists from the United States successfully reset the kidneys, skin and other cells in middle-aged and elderly mice to a youthful state through gene therapy, thereby reversing the aging process of mice.
During this process, the mice did not have any negative effects on their health, behavior, or weight, that is, no side effects were found.
Therefore, scientists say that this is a safe and effective "rejuvenation" technique.
Currently, the results have been published in Nature Aging.
So, exactly, what exactly makes mice "live younger and younger"?
Can this technology be used in humans?
A thing called the "Mountain Factor."
The aging of life is manifested at the microscopic level as the "aging" of cells.
In other words, every cell in an organism carries a "molecular clock" that records the passage of time.
Back in 2006, Japanese scientist Shinya Yamanaka discovered that adding a mixture of four reprogramming molecules (Oct4, Sox2, Klf4, and cMyc, also known as "Yamanaka factors") to cells could reverse the molecular clock and reset the epigenetic markers associated with aging to their original patterns.
This cell therapy manifests itself in the reorganization of adult cells into stem cells that can differentiate into various cells.
Nobuya Yamanaka himself won the Nobel Prize in Physiology or Medicine for this achievement.
As early as 2016, the Salk Institute of Biology in the United States has made preliminary attempts to use mountain factors to extend the lifespan of mice with Progeria disease by 30%.
In 2020, a blockbuster study published in Nature also used three molecules in the Yamanaka factor to restore the vision of older mice (or those with glaucoma) whose vision had deteriorated.
However, the effect of long-term reprogramming using yamanaka factors on naturally aging mice is unclear.
To that end, the Salk Institute decided to find out again.
In this study, the scientists gave three groups of mice of different ages regular injections of Yamanaka factor.
Among them, the first group of mice is 15-22 months old, equivalent to the age of 50-70 years old in humans;
The second group of mice has a large age span, 12-22 months old, equivalent to 35-70 years old in humans;
The last group of mice is 25 months old, equivalent to the age of 80 years in humans.
The first two groups received treatment for 7 months and 10 months, respectively, while the last group was treated for only 1 month.
Scientists also want to see if long-term reprogramming treatments are safe.
Recovery after injury is faster and scarring less likely
What were the results of the experiment?
After months of long-term treatment, the scientists found that there were no abnormalities in the blood, nervous system, and other aspects of the mice, nor did they produce cancerous changes — which was once the biggest concern of scientists about factor-related treatment in yamanaka.
Instead, the mice showed signs of rejuvenation in many ways:
In terms of kidneys and skin, the epigenetic patterns of the mice in the experimental group were more similar to those of young mice;
After injury, the proliferation ability of the skin cells of the mice in the experimental group became stronger and left almost no scars; ordinary elderly mice recovered more slowly after injury and were prone to permanent scars.
In addition, the metabolic molecules in the blood of the mice in the experimental group did not show any changes brought about by age.
However, these effects only appeared in the first two groups of mice, and the mice that had only been treated for one month did not change much.
This suggests that long-term treatment is more effective.
In addition, we also need to note that this treatment is not just a pause in aging, but a direct reversal.
Next, the researchers will explore how long this effect can last.
They also say that although the method is still early in humans (such as treating aging-related diseases: cancer, Alzheimer's, etc.), at least we already see hope in mice.