The proteoglycan chondroitin sulfate (CSPG) plays an important role not just in the formation of the glial scar but also in the repair of spinal cord injury, according to an article released on August 18, 2008 in the open-access journal PLoS Medicine.
In injuries to the central nervous system such as spinal cord injury, the glial scar is formed in a similar manner to scars in other parts of the body. However, while protecting the damaged area in many ways, it simultaneously releases chemicals that inhibit further regeneration. Within the glial scar, several major types of cells appear, in particular microglia and macrophages. The proteoglycan molecule chondroitin sulfate plays a vital role in the inhibition of neuronal regeneration, but according to the article, the increased synthesis of this compound indicates it might actually play a dual rold in this process.
Michal Schwartz, of the Weizmann Institute of Science, and colleagues performed several experiments in mice to explore this dual role in the acute phase of healing after a spinal cord injury. Evaluating spinal cord damage through the proteins and cells that are present, the researchers postulate that the proteoglycan in fact has an important role in the healing process by controlling intervening cells in communication pathways.
They conclude that the present goal to reduce expression of chondroitin sulfate may not be productive, and that it may be more important to modulate it in therapies for such injuries. They say that “timing and the extent of degradation should be carefully selected according to the changing requirements of the ongoing dynamic repair process.”
They conclude with a call for further research in the formation and maintenance of the glial scar: “Moreover, since CSPG is a major constituent of the glial scar, the present findings raises the potential need to revisit the overall perception of the glial scar and its role in recovery. A better understanding of the regulation of the scar tissue and the role of the naturally occurring CSPG in health and disease will enable us to increase the benefit of endogenous repair mechanisms and improve many of the available therapies for CNS injury.”
Two faces of chondroitin sulfate proteoglycan in spinal cord repair: A role in microglia/macrophage activation.
Rolls A, Shechter R, London A, Segev Y, Jacob-Hirsch J, et al.
PLoS Med 5(8): e171.
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Written by Anna Sophia McKenney