American researchers from the Houston Methodist Hospital managed to find a new method for stopping a serious genetic disease - Progeria, which is characterized by premature rapid aging of the body. It was found that hypothetically, the condition of patients can be improved by using substances aimed at telomeres (areas of chromosomes that shorten with age), and not at a defective gene.
Progeria is a very rare disease. There is a childhood form (called Hutchinsaw-Guildford syndrome) and an adult form (called Werner syndrome). A study by researchers in the Netherlands suggests that approximately one child in four million people is affected by the disease. In total, about 140 cases have been recorded in the world, but at the same time, scientists are convinced that this is far from a complete picture, and there are at least twice as many cases. Children suffering from progeria, as a rule, do not live to adulthood.
However, there are exceptions. So, in particular, the musician and artist from South Africa Leon Botha died at the age of 26. He adhered to a fairly active lifestyle, was engaged in DJing, starred in videos, and also organized art exhibitions. He also worked with the hip-hop group Die Antwoord. At the age of 20, he underwent successful heart surgery. This operation was prophylactic, and was done to prevent attacks of atherosclerosis. About a year before his death, Botha suffered a stroke, after which his health deteriorated markedly.
According to scientists, the main cause of the childhood form of progeria is a random mutation within the LMNA gene, which is responsible for the synthesis of the protein prelamin A, which is involved in the formation of the lamina - the inner membrane of the cell nucleus. This membrane is of great importance in the process of DNA copying and cell division. In addition, this shell provides the level of substances that are necessary to repair damaged DNA. In the event that the LMNA gene is defective, then a damaged analogue of prelamin A, progerin, is formed, which cannot become part of the nuclear membrane. Ultimately, the shell becomes weakened and can no longer provide sufficient structural support to the nucleus. Thus, the cells lose their ability to divide normally.
This has a negative effect on the entire child's body, systemic disorders are manifested from birth, but despite this, the disease can only be determined after a few years. The child's hair begins to fall out, the face acquires specific features (small jaw, pointed nose, big eyes), the skin becomes thinner, muscle atrophy occurs, damage to internal organs and blood vessels. All these changes are the result of rapid molecular changes that are triggered by mutations in a single gene. A patient suffering from progeria dies of renal failure or complications of atherosclerosis.
However, researchers are in no hurry to equate Progeria with aging. Some senile diseases are not typical for people with Hutchinson-Guildford syndrome. As a rule, such patients do not suffer from dementia, do not become more susceptible to osteoarthritis or cancer. At the same time, certain pathological changes, even those that occur at the molecular level, are very similar to those that occur in the body of the elderly. In the case of progeria, telomere shortening is observed (these are the ends of chromosomes that are responsible for protecting genes from damage caused by final underreplication).
Terminal underreplication is a common occurrence during DNA copying. The enzyme DNA polymerase cannot synthesize a copy of DNA from the very beginning. Thus, the new chromosomes are slightly shorter than their predecessors. For cells, this could be a real disaster, but only if important parts of the genes were lost. However, according to scientists, chromosomes have special “caps” - telomeres, which do not carry any important information. In the process of replacing one generation of cells with another, telomeres are gradually shortened. It is quite obvious that this process cannot continue indefinitely. Telomeres at some point become too short, so they can no longer protect important DNA from damage.
The length of telomeres allows a certain maximum number of cell divisions, which is commonly called the Hayflick limit. For cells of the human body, this limit is 52. As cells approach this limit, they acquire signs of aging, and then die. Cells with an active telomerase enzyme, telomeres are able to elongate, which theoretically makes them immortal (cancer cells can be called as an example). At the same time, the relationship between aging of the body as a whole and telomere shortening is still unclear. Some studies have shown that life span and telomere length are not related. But in a scientific study by specialists from the Spanish National Cancer Institute, it was proved that after injections of the telomerase gene in mice, life expectancy increased by 13 percent.
Promotional video:
Thus, the length of telomeres still has a definite connection with the general aging of the organism. But this connection is not direct. This is also indicated by the results of research by scientists from the United States. They found that the state of cells with a mutated LMNA gene can be improved with telomerase. Scientists came to similar conclusions after placing the material responsible for the synthesis of polymerase into cells isolated from sick children. This terraria was more efficient than previously conducted. Various markers of cell aging became less obvious, in particular, the number of inflammatory proteins decreased. In addition, some of the markers have disappeared completely.
As noted by the researchers, in the coming years, there may be studies with human participation. The methods of therapy that exist at the present time are ineffective and can prolong the life of people suffering from progeria by only a few years.