Estrogen produced during pregnancy could reduce multiple sclerosis relapses by 70%.
A new study has uncovered the cellular mechanisms underlying how estrogen can prevent damage to the central nervous system in patients with multiple sclerosis (MS).
The authors found that estrogen therapy has a positive effect on immune cells in the brain and oligodendrocytes, according to a study published by Brain. These findings suggest that dual action on these types of cells may protect against MS.
Previous studies show that relapse rates plummet by 70% during the third trimester of pregnancy among women with MS compared with relapses before pregnancy. Other research has suggested that women with MS who have multiple pregnancies may experience long-term benefits, but the reasons have been unknown.
In prior mice and clinical trials, researchers found that a pregnancy-related estrogen made by the fetus and placenta may be involved in the reduced relapse rate. Results from the animal study showed that estrogen protected the brain by activating the estrogen receptor beta (ERb) protein.
In the current study, the investigators identified which cells are responsible for the protective effect against MS as a result of estrogen.
First, the researchers deleted ERb in immune cells of the brain and in oligendrocytes—both involved in myelin production—to ensure that cells were unresponsive to estrogen, according to the study.
Mice with and without ERb were treated with an estrogen-like compound to determine the level of disease protection. Loss of protection was defined as the treatment was acting on the cell that had the receptor removed, according to the authors.
The results demonstrated that estrogen acted on brain immune cells and oligodendrocytes. This action was shown to induce the repair of myelin and resulted in less disability, according to the study.
The authors noted that current approaches to drug development typically only target a single cell type, which may not be adequate for MS treatment.
The study results suggest that an estrogen-like compound may treat MS by taking a complementary effect on 2 different types of cells, according to the authors.
The researchers said they are currently working to develop a next-generation estrogen-like compound that has biochemical effects on both brain immune cells and oligodendrocytes.