Progeria at the molecular level
Scientists have found out the causes of early aging of children
Alexey Yevglevsky, Naked Science
Hutchinson-Guilford syndrome is a rare genetic defect that causes signs of early aging in children. Because of this syndrome, children die in adolescence, often before reaching adulthood. Geneticists from St. Louis University have found out the reasons why this defect occurs.
A group of scientists led by Susana Gonzalo called the mechanism that causes Hutchinson-Guilford syndrome "replication stress". It appears due to a mutation in the LMNA gene, which encodes the protein lamin A. Lamin A is responsible for the stable formation of new cells. With the correct operation of this protein, new cells retain their former shape and structure. A shortened version of this protein is called progerin. It causes incorrect cell division, due to which the cell nucleus is copied with an error.
Since the nucleus stores DNA, incorrect replication of the nucleus leads to mutations within the DNA, which leads to the formation of cancer cells and aging.
Gonzalo's team discovered two mechanisms that cause damage to the body. The first one manifests itself in a violation of the well-coordinated work of replication. Usually the cells find a way around the obstacle and continue to divide, but progerin causes this process to stop. Cells that are unable to divide cause premature aging. The second mechanism is associated with the release of DNA outside the nucleus. She told me about him Susana Gonzalo:
"When DNA fragments go beyond the nucleus and enter the cytoplasm, they are perceived by the body as foreign material. This activates an immune response known as an interferon response. In this case, the cell believes that a bacterial infection has penetrated inside and it must be fought. We observed this process in progeria cells, which reduced cell division."
Geneticists have found that the process can be slowed down by using vitamin D: "When we block this pathway with vitamin D, the cells rejuvenate. The immune response is activated by progerin, and then everything is restored by vitamin D."
Gonzalo hopes that their discovery will not only help fight Hutchinson-Guilford syndrome, but also open up new perspectives in understanding the aging process itself. Recently, scientists have found the main cause of aging of human muscles.
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