Researchers have discovered new targets for recovery of motor function after spinal cord injury. The study, which will be published in the April 2012 issue of The American Journal of Pathology, suggest that FTY720 administration can cause nerve regeneration, and therefore recovery of locomotor function.
FTY720 acts as an S1P receptor modulator, that is sphingosine 1-phosphate, a lysophospholipid mediator. Researchers from the Jichi Medical University School of Medicine and the Graduate School of Medicine at the University of Tokyo, have found that sphingosine 1-phosphate (S1P) is found in high concentrations at the site of nerve injury. The role of the lysophospholipid mediator is to attract nerve progenitor cells at contusions, helping to regenerate. Researchers have thought that by acting on S1P receptor might help in the treatment of central nervous system diseases, such as spinal cord injury or SCI.
Spinal cord injury refers to the damage of the spinal cord. Symptoms vary depending on where one is injured: if the injury is located on the cervical spine, the patient will lose motor function of both arms and legs. In this case, the condition is called quadriplegia. If the damage is below the lumbar spine, only the feet will be affected, and it is called paraplegia. Besides the loss of motor function, there are other disorders, such as difficulty when breathing, incontinence, spasticity and many others.
The study has promising results so far and is especially valuable as, until now, no therapies have been found in order to help the regeneration of nerve injury.The researchers found that there is a significant improvement soon after administration of FTY720 in mice. In other words, FTY720 help recover motor function by immunomodulation. In addition, scientists have noted that FTY720 cause lymphopenia, that is decreasing the number of lymphocytes in the blood. This is beneficial in the spinal injury because T cell infiltration is reduced. However, this does not affect and infiltration of neutrophils, which play a role in microglial activation. It is important to note that microglial have an important function in the regeneration of spinal injury.
Lead investigator Yoichi Sakata, MD, PhD, Research Division of Cell and Molecular Medicine, Center for Molecular Medicine, Jichi Medical University School of Medicine, underscores the importance of this discovery and the enormous potential this research has : ‘These data clearly indicate the importance of immune-independent functions of FTY720 in the amelioration of functional deficits after SCI in mice.” He also added that targeting S1P receptors by FTY720 is an attractive therapeutic approach for treating spinal cord injury.