Progesterone, a female hormone that is primarily used in reproductive health, has undergone a drastic change in the world of research. For a period of time, sex hormones were only believed to function in the scope of reproduction and sexual health, with possible implications on how humans develop in the womb. However, further research has suggested that other implications, specifically those in the neurobiological functions, of both women and men could exist. The focus of these studies in neurobiology link progesterone and other steroids to multiple factors in how humans function, but a sub-section of this research is dedicated to its role in myelination. Myelination is the process of lining an axon of a neuron with a protective coating made to provide support, protection from any damage that may occur to the neuron and, most importantly, allow insulation on the axon to allow electrical signaling to become quicker. However, because of its location on the axon of the neuron, it provides easier access to damage from neurological disorders. This damage can also spread to the neuron itself, making it difficult for regeneration. However, progesterone has played a key role in understanding not only the mechanisms of myelinating, but also the process of repairing the damage to myelin sheaths itself for disorders like multiple sclerosis.
In research done by Dr. Abdel Mouman Ghoumari from the University of Paris-Sud, the neurological aspects of progesterone are observed, specifically their effect on myelination and myelin repair in the brain. The process of myelination allows electrical signals from other neurons to travel quicker in the brain and communication between major neurons to become more efficient. Dr. Ghoumari uses the method of cryolesion to isolate sciatic nerves in mice, which keeps the basal lamina tubes intact to support regeneration. A week is given to allow regeneration, and after this week is completed, progesterone was injected to these sites. During this week period however, the myelin sheaths had only reached about 1/3 of the typical size required to provided adequate insulation. The injection of this progesterone (100 micrograms locally) showed an increase in the production of remyelination of axons. The evidence of this study, as well as the meta-analysis of other studies cited in the paper, clearly indicates that progesterone plays a very important role in the creation of myelin sheaths, possibly even Schwann cells as a whole, and also suggested the use of progesterone for disorders in myelination, such as multiple sclerosis.
Further work conducted by this group explored how progesterone could play a role in multiple sclerosis, which is more likely to develop in women when compared to men. Mouse models were once again used, with the mechanism of progesterone and testosterone in relation to the myelinating of pre-mature oligodendrocytes. After the mechanism was developed, progesterone was identified as playing a major role in the regulation of proliferation or the differentiation of myelinating cells, which is a significant event for those who develop multiple sclerosis. In an in vitro study, 3B-HSD (progesterone) was positively identified in cell cultures of pre-mature oligodendrocytes, suggesting that the synthesis of progesterone is a key function of oligodendrocytes’ maturation. After this was understood, cerebellar slice cultures were captured from mice, and upon injection of progesterone, myelination of targeted axons was noticed. This effect was compared against knock-out mice, where the effect was not noticed. In an in vivo study, where male mice had spinal cord injuries, the mice were injected with progesterone showed an increase in the number of pre-mature oligodendrocytes produced, and a decrease in the number of astrocytes and inflammation factors like interleukin-1B.The combination of this research and those conducting similar research to Dr. Ghoumari’s group have identified not only does progesterone and other sex hormones play a major role in neurological aspects of human (and animal function), but also that these effects could be used to reverse the destruction of disorders related to the function of myelination in oligodendrocytes, such as multiple sclerosis.
Citations:
1. Ghoumari, M. A., et. al. (2020). Roles of Progestrone, Testosterone and Their Nuclear Receptors in Central Nervous System Myelination and Remyelination. MDPI, 21 (9). 3163; https://www.mdpi.com/1422-0067/21/9/3163
2. Schumacher, M. et. al. (2022). Progestrone Synthesis in the Nervous System: Implications for Myelination and Myelin Repair. Frontiers in Neuroscience, 8, 9. https://pmc.ncbi.nlm.nih.gov/articles/PMC3274763/
No comments:
Post a Comment