February 22, 2007
Researchers report that significant changes occur in the tissue of brain and spinal cord of pregnant mice that may help to explain why remission occurs in many women with multiple sclerosis during pregnancy. Christopher Gregg, PhD, and colleagues (University of Calgary, Alberta, Canada) report their findings in the February 21stissue ofJournal of Neuroscience(2007 27:1812-1823).
Understanding the gender differences in MS for example, that women get MS twice as often as men, or that women with MS who are pregnant often experience remissions can provide new information about MS, its cause and even its treatment. Much research has pointed to gender differences in the immune attack launched on nerve fiber-insulating myelin in MS. In addition, recent research funded by the National MS Society showed for the first time functional differences in the myelin itself, indicating that the turnover of myelin-making cells is significantly higher in female mice (The Journal of Neuroscience2006 26:1439-1447).
Dr. Gregg’s team tested the hypothesis that pregnancy would increase the proliferation of myelin-making cells. They found significant increases early in pregnancy of myelin-making cells, myelin formation, and the capacity for myelin repair. Furthermore, prolactin the hormone that stimulates lactation regulated these effects. Administering prolactin treatments to non-pregnant female mice with myelin damage promoted myelin repair.
This study provides exciting new information on gender differences in MS. If confirmed, the findings may present a new therapeutic strategy for MS utilizing prolactin. Others have reported that prolactin affects the immune system; however, it is unclear whether its effects would intensify the immune response which is unfavorable in MS.
Similar results in the field of gender differences already have been translated from the laboratory to clinical trials, most recently withthe firstlarge-scale trialof a pregnancy hormone for the treatment of MS, funded by the Society.