Multiple sclerosis : a molecule induced by testosterone is promising
Published the 30.01.2018 at 08: 30 am
Update the 30.01.2018 at 10: 30
Researchers at Northwestern university, in the United States, have discovered why men were less likely to develop multiple sclerosis than women. By identifying a molecule whose production is triggered by a testosterone level high in the blood – they found that it helped to protect them from disease.
In the course of this study, published in PNAS, female mice from a model of brain disease autoimmune such as multiple sclerosis have been treated with interleukin-33, a molecule that would be protective. Its production is induced by a high level of testosterone in the blood, and their neurological symptoms were eliminated.
“This explains the higher risk reduced in men to develop multiple sclerosis and other autoimmune diseases (lupus, rheumatoid arthritis, multiple sclerosis), compared to women, says Melissa Brown, professor of microbiology at the University of Northwestern. These results could lead to a new type of treatment for the MS, via interleukin-33, or the ways that it stimulates, and which we greatly need.”
Testosterone in rampart
In fact, women have three to four times more likely to suffer from MS than men because their levels of natural testosterone is 7 to 8 times lower than among men. Other by, the SEP is triggered later in life in men, at an age when testosterone levels begin to decline. But until now, scientists had not understood how the testosterone could provide protection to men.
“This is why it is essential to study the differences between the sexes in research”, hammered Dr. Brown. Testosterone, administered to men with MS has had a positive influence on the destruction of myelin and nerve fibre degeneration, but this treatment is not possible in the long term. However provide the protein whose production is induced by testosterone, or stimulate in a different way the immunologic response to Th-2, would be possible.
A disease that attack the myelin
In the case of MS, there is an imbalance of the immune system and immune cells, in particular Th-17, attack the myelin sheath (the white substance that wraps nerve cells or “neurons”). Initially, the myelin sheath acts as an insulator and helps to send nerve signals to the brain and the spinal cord to the rest of the body.
When the myelin sheath is damaged, the normal conduction of the nerve signal is interrupted, which can cause a variety of neurological symptoms, such as sensory disturbances, loss of motor function and cognitive deficits.
A new molecule promising
Testosterone promotes the development of the formation of mast cells (a type of immune cell) that produces a protein with a key role in the cascade of inflammation, the cytokine IL-33. This in turn triggers the activation of a cascade of proteins of the inflammation that prevents the development of another type of immune cell, called Th17 cells, which they can directly attack the myelin. It is thanks to this mechanism of direct inhibition via IL-33, lymphocytes, Th-17, as young men would be better protected from multiple sclerosis as women.