The researchers have found that spreading of a certain type of cells known as oligodendrocytes present in the central nervous system of mice who already has multiple sclerosis plays a critical role in the development of the disease. This new discovery can help many of the doctors to look for other different therapies which will work on other parts of the body and not only on the immune system.
The findings of the study got published in the journal ‘Nature Medicine’ at the Karolinska Institute in Sweden. Around two and a half million multiple sclerosis cases are there worldwide of which 18,000 are of Sweden. Approximately 1,000 new cases of multiple sclerosis are reported every year.
One suffers from multiple sclerosis when the white blood cells of their own body attack the fatty substance called myelin sheath of the axons in the central nervous system. This disturbs the pathway of proper nerve signal transmission and leads one to the development of the disease.
Though still, the cause of this disease is unknown, as to why the white blood cells attack the myelin sheath, the study led by the researchers at Karolinska Institute finds out that the cells which are responsible for the production of myelin itself play an unexpected role. These cells are oligodendrocytes, which are usually found in the brain and spinal cord of the human being.
“Our study provides a new perspective on how multiple sclerosis might emerge and evolve,” says Gonçalo Castelo-Branco, associate professor at the Department of Medical Biochemistry and Biophysics, Karolinska Institute.
“Current treatments mainly focus on inhibiting the immune system. But we can now show that the target cells of the immune system in the brain and spinal cord, oligodendrocytes, acquire new properties during disease and might have a higher impact on the disease than previously thought.”
As per the researchers, the subset of oligodendrocytes and their progenitor cells are more likely similar to the immune cells of the mouse with multiple sclerosis.
Both oligodendrocytes and its progenitor remove the myelin that is damaged by the disease, showing the same function as immune cells. One of the most amazing facts is that these oligodendrocytes progenitor cells can direct the immune cells to change their behavior and act differently.
“We also see that some genes that have been identified as those that cause a susceptibility to Multiple sclerosis are active (expressed) in oligodendrocytes and their progenitors,” says Ana Mendanha Falcão, joint first author of the study with David van Bruggen, both at the Department of Medical Biochemistry and Biophysics at Karolinska Institute.
“All in all, this suggests that these cells have a significant role to play either in the onset of the disease or in the disease process,” says David van Bruggen.
The study was carried out by one of the newly developed techniques that is single-cell RNA sequencing. This technique is much efficient in providing the snaps of the single cells and helping them to observe the genetic activity as well as the ability to differentiate the characteristics of every single cell.
The technique has now made possible to find out the different roles and functions carried out by various cells. Although the study was conducted out on mice, the results show some similar observations in human samples.
“We will now continue with further studies to ascertain the part played by the oligodendrocytes and their progenitor cells in MS. Further knowledge can eventually lead the way to the development of new treatments for the disease,” says Gonçalo Castelo-Branco.