10 April 2013

The gene for premature aging

Researchers from the University of Western Ontario, working under the guidance of Dr. Nathalie Berube, have demonstrated that the absence of the functional ATRX gene in mice leads to problems in the work of the forebrain – the region of the brain involved in learning and memorization, as well as the anterior pituitary lobe, which directly affects the growth and metabolism of the body.

In clinical practice, children with ATRX gene defects are characterized by impaired cognitive function and developmental abnormalities. The relationship between mutations of this gene and predisposition to the development of brain cancer is also known.

As part of their work, the authors first established that the loss of the ATRX gene leads to DNA damage, mainly localized at the end sites of chromosomes – telomeres. Further study of this phenomenon has shown that the cause of such damage is a violation of the DNA replication process that occurs before the cell division begins. In essence, it turned out that the protein product of the ATRX gene is necessary for successful telomere replication.

The mice created by the researchers that did not have the ATRX gene had a small body size at birth and died very quickly. The study of the animal skeleton showed a very low level of bone mineralization. Moreover, they were found to have a tendency to develop cataracts, hypertrophy of the heart and hypoglycemia, that is, many symptoms associated with aging.

The authors claim that the absence of the ATRX protein in the cells of the anterior pituitary gland disrupts the thyroid gland, which is manifested by low blood levels of a hormone known as insulin-like growth factor-1. According to many experts, low levels of insulin-like growth factor-1 cause depletion of stem cell reserves in the body, which is one of the possible explanations for premature aging of animals without the ATRX gene.

Article by L. Ashley Watson et al. Atrx deficiency induces telomere dysfunction, endocrine defects, and reduced life span is published in the Journal of Clinical Investigation.

Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of the University of Western Ontario:
Shedding light on a gene mutation that causes signs of premature aging.


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