Fibrinogen: Blood-Clotting Protein, Inhibits Spinal Cord Regeneration

Filed in archive Genomics, Proteomics and Bioinformatics on July 10, 2007

The growth of central nervous system neuronal cells is a process that is necessary for the regeneration of the spinal cord after traumatic injury.

A blood-clotting protein found in circulating blood - fibrinogen- has been found by UCSD researchers to inhibit the growth of the said central nervous system neuronal cells, thereby inhibiting spinal cord regeneration.

According to Katerina Akassoglou, Ph.D., assistant professor in UCSD's Department of Pharmacology who led the study:

"Our study shows that fibrinogen directly affects neurons by inhibiting their ability for repair. Fibrinogen -- contained in the blood which leaks at the site of injury -- begins the process of inhibiting axonal growth by binding to the beta 3 integrin receptor. This binding, in turn, induces the activation of another receptor on the neuronal cells, called the epidermal growth factor receptor. When the second receptor is activated, it inhibits the axonal growth. Other inhibitors have been identified that use the same epidermal growth factor receptor, but this is the first blood-derived inhibitor that has been found.

Inhibiting the damaging effects of fibrinogen on neurons may potentially facilitate repair in the nervous system after injury. A similar mechanism could be at work in other neurological diseases that result in paralysis, such as multiple sclerosis or hemorrhagic stroke, where blood vessels break and bleed into the brain. She added that such a therapeutic approach wouldn't interfere with fibrinogen's essential role in coagulation, because its blood-clotting mechanism depends on binding with a different receptor.

Findings have been published in the online issue of the Proceedings of the National Academy of Sciences on July 2.

Find more details from the full report.