Who is to blame for the aging of bones?
Researchers at the University of Buffalo in a new study have shown that the absence of a protein that regulates inflammation accelerates the processes of bone resorption, increasing the risk of periodontitis and, possibly, osteoporosis.
Osteoporosis leads to a decrease in the mechanical strength of bones. Patients suffer from pathological fractures that occur with frivolous falls and bumps. A decrease in bone mineral density is observed in 55% of people over 50 years of age. By 2020, 61 million people worldwide are projected to have osteoporosis.
The situation with periodontitis is also gloomy – a disease characterized by inflammation of the gums, destruction of the jaw bones and leading to the loss of teeth. It affects 70% of people over 65 years of age.
Inflammation is an important part of the body's immune response, protecting against infections and damage. But excessive inflammation leads to bone destruction and disruption of bone synthesis.
The protein tristetraproline (TTP) plays the role of a brake on the immune system. Without it, the processes of inflammation and resorption of bone tissue occur uncontrollably and uncontrollably.
The results of an experiment with suppression of the production of TTP. On the left – the control group, in the middle – the experimental group. Removal of the gene responsible for the synthesis of TTP leads to an increase in the number of osteoclasts (purple), which destroy bone tissue. Source: Keith Kirkwood.
A decrease in the level of TTP with age causes the development of aging–related diseases - osteoporosis and periodontitis. It remains unclear what is the reason for the decrease in TTP synthesis. Understanding the factors underlying the expression of genes encoding TTP will help develop new ways to treat bone diseases.
To assess the effect of TTP levels on the risk of periodontitis, the researchers conducted an experiment with three groups of mice. In the first, the synthesis of TTP was completely suppressed, in the second, on the contrary, it was strengthened. The third group of mice was a control group.
In animals, inflammatory changes, jaw bone density and the number of osteoclasts (cells that destroy bone tissue) were monitored three, six and nine months after the start of observation.
In mice of the first group (with suppression of TTP synthesis), periodontal bone density it decreased by 14% after three months and by 19% after nine months. In addition to periodontitis, they were diagnosed with eczema, arthritis and other inflammatory diseases. The level of osteoclasts was higher than in the other two groups.
The absence of TTP also led to a change in the microflora of the oral cavity, despite the content of all mice participating in the experiment in the same conditions. The authors suggested that long-term chronic inflammation led to this. It remains to be seen whether the growth of pathogenic microflora plays a role in the development of periodontitis.
Increased expression of TTP in the second group of mice led to resistance to inflammation. Bone resorption processes were 13% lower compared to the control. The number of osteoclasts in this and control groups was the same.
Currently, it is planned to study the effect of the TTP level on bone density over a two-year period.
Article by H.M. Steinkamp et al. Tristetraprolin Is Required for Alveolar Bone Homeostasis published in the Journal of Dental Research.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru based on the materials of the University of Buffalo: Absence of key protein, TTP, rapidly turns young bones old.