The Effects of Glial Cell Line-Derived Neurotrophic Factor after Spinal Cord Injury

Spinal cord injury (SCI) is a devastating condition affecting 270,000 people in the United States. The use of growth factors is a potential treatment for reducing secondary damage, promoting axon growth, and restoring some of the lost function post-SCI. Glial cell line-derived neurotrophic factor (GDNF) is an important growth factor, because it can affect both neurons and support cells. Here, we give an in-depth review of the previously published literature where GDNF was used to treat SCI. The effects of GDNF have been shown to decrease lesion size, improve allodynia, and regenerate axons in the central nervous system and peripheral nervous system. GDNF is necessary for early development, and lack of GDNF can lead to abnormal development of the autonomic nervous system or death. Exogenous administration of GDNF either before or immediately after SCI is most effective. Even though GDNF can be directly administered, genetically modified cells are often used as a delivery vehicle. Several different types of genetically modified cells have been used with varying success. Although GDNF is effective when used alone, it has been shown to be more effective when used in combination with other neurotrophic factors. Overall, GDNF significantly improved functional recovery, increased the number of sprouting neurons, reduced lesion size at the injury site, and had minimal adverse effects.