Researchers in Russia found for a first time an association between variants in GAL, a gene that codes for the galanin protein, and multiple sclerosis (MS). Importantly, they also found that this association is sex specific.
The study, “Single-nucleotide polymorphism rs948854 in human galanin gene and multiple sclerosis: a gender-specific risk factor,” was published in a special issue of the Journal of Neuroscience Research dedicated to research into brain differences, at all levels, between men and women.
Galanin is a neuropeptide encoded by the GAL gene that is widely expressed in the brain, spinal cord, and gut of humans and other mammals. Evidence from recent studies points to elevated levels of the galanin protein in post-mortem brain samples of MS patients.
Dr. Victoria Lioudyno with the Pavlov Department of Physiology, Institute of Experimental Medicine in St. Petersburg, and colleagues compared the frequency of “more active” and “less active” variants of the DNA sequences that control expression of galanin in 111 MS patients and 115 healthy matched controls.
Initially, the researchers found no group differences, but when they considered gender, they observed a twofold decrease in the “less active” genetic variant in healthy men compared to healthy women.
Analyses also revealed that the presence of this variant increased susceptibility to MS in men but not in women, and in men was significantly associated with a delayed MS onset.
Researchers also found that this GAL variant affected the rate of MS progression depending on the sex of the patients. Women with the “less active” genetic variant had a significantly faster progression rate than those who did not.
“We hope that our findings will foster development of a personalized strategy for the prevention and treatment of multiple sclerosis, one that takes into account the gender-specific contribution of galanin gene variants to susceptibility and disease progression,” Lioudyno, the study’s lead author, said in a news release.
“Neuroscience today is at a crossroads. Do we continue the status quo and ignore sex as a biological variable, or do we acknowledge that sex influences the brain at all levels and address the major gaps in knowledge?” said Dr. Eric M Prager, the journal’s editor-in-chief. “The work published in this issue unequivocally concludes that sex matters and that researchers can no longer allow for the over-reliance on male animals and cells, which obscure key differences that might influence clinical studies.”