Can estrogen hormones slow MS progression? Study says maybe yes.
Estradiol in particular may help when disease is triggered by viral infections
In progressive forms of multiple sclerosis (MS), treatment with estrogen hormones such as estradiol may help reduce inflammation and nerve damage — especially among patients for whom the disease may be triggered or worsened by viral infections — a mouse study has found.
U.S. researchers investigating the impact of sex hormones in a mouse model of MS discovered that disease symptoms were fewer or less severe in treated animals, particularly those given estradiol, six months after a viral infection.
The use of estradiol also was seen to reduce damage to the myelin sheath, the protective coating around nerve fibers whose loss underlies MS.
According to the researchers, the study’s findings “support estrogen’s potential as [a] multiple sclerosis therapy in virus-driven disease.”
The study, “Therapeutic effects of estrogens on inflammatory demyelination in a mouse model of multiple sclerosis,” was published in the Journal of Neurobiology by researchers at Texas A&M University.
MS occurs when the body’s immune system mistakenly attacks the myelin sheath, which coats nerves in the brain and spinal cord much like insulation around electrical wires. The damage caused by such attacks interferes with nerve signals and leads to a range of symptoms.
In progressive forms of MS, symptoms gradually worsen over time due to ongoing nerve damage, which can eventually lead to increasing disability, even without clear relapses.
Researchers focused on MS progression in females
Overall, the disease is diagnosed 2-3 times more often in women than in men, and the point at which MS becomes progressive in female patients overlaps with the age of menopause. This may be linked to how sex hormones fluctuate as women transition from one stage of life to the next.
After menopause, the body stops producing significant amounts of estradiol — the main form of estrogen in women during their reproductive years — which may explain the worsening of disability from that point onward. In contrast, sex hormones present during pregnancy or in contraceptives for birth control appear to ease symptoms of MS.
To understand how these sex hormones may affect the underlying mechanisms of MS, the researchers turned to a mouse model that mimics the disease. The scientists infected female mice with the Theiler’s murine encephalomyelitis virus (TMEV), which causes the myelin sheath to become inflamed and damaged in a way that closely resembles MS. Some mice were left uninfected to serve as controls.
Fifteen weeks after infection, all mice had their ovaries removed to eliminate naturally produced sex hormones. They were then given slow-release hormone pellets containing either estradiol, estriol — a type of estrogen that increases during pregnancy — or a placebo.
Given the current acknowledgment that viral infections are causative agents in MS [disease mechanisms], these observations may be beneficial in therapeutic interventions in human MS. … [These findings] support estrogen’s potential as [a] multiple sclerosis therapy in virus-driven disease.
The goal was to watch for changes in the course of the disease over time, with a focus on determining their potential effectiveness.
The data showed that, compared with mice given the placebo, those treated with the sex hormones, particularly estradiol, had significantly fewer or less severe symptoms at about six months after infection.
Estrogen hormone estriol may protect nerves from demyelination
At the end of the study, the researchers examined the mice’s spinal cords. Both estradiol and estriol reduced inflammation, but estradiol was the only one that reduced damage to the myelin sheath.
This suggests that while both sex hormones help reduce inflammation, estradiol may better protect nerves from demyelination, or the loss of the myelin sheath, the researchers noted.
“Given the current acknowledgment that viral infections are causative agents in MS [disease mechanisms], these observations may be beneficial in therapeutic interventions in human MS,” the team wrote.
According to the researchers, “these results suggest that estrogens may be effective therapies for progressive multiple sclerosis induced by viral infections.”
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