Increased dietary salt was reported to increase the immune attack on myelin in three studies this week. All three were published in the journal Nature.
- A study by Kleinewietfeld, et al, looked at TH17 cells, which is a type of lymphocyte that is highly inflammatory and that causes substantial tissue damage. These cells were grown in cultures in the lab. Some had normal and others high salt levels in their cultures. Those grown in a high salt environment had increased markers for inflammation. This seemed to be due to activation of one particular set of chemical signals in the cell, called the p38/MAPK pathway. They also looked at mice with an MS-like disease called experimental allergic encephalomyelitis (EAE). Mice fed a high salt diet had worse EAE than those fed a normal diet.
- A study by Wu, et al, also looked at TH17 cells. An analysis was done on genes associated with activation of TH17 cells, and SGK1 was identified as an important protein in this process. The SGK1 pathway was found to be more active if cells were cultured in a high salt environment. This was then studied in mice with EAE. Mice fed a high salt diet had more severe EAE. Blocking the SGK1 pathway seemed to reverse the effect of the high salt diet on the EAE.
- A study by Yosef, et al, also looked a the genes associated with activation of TH17 cells. They identified 22 sets of related genes that increased TH17 cell activity and 5 that decreased activity.
TH17 cells are highly inflammatory and likely contribute to the severe damage done to tissues in a number of diseases. Their precise role in MS is not fully understood, but it is believed that ...