July 30, 2009

Weekly News UpdateBlue Dye May Prove Useful in Treatment of Spinal Cord Injuries

Researchers at the University of Rochester Medical Center (URMC) have found that a substance similar to the common food dye that gives M&Ms their bright blue color has been shown to help reduce the effects of spinal cord injuries if injected soon after the injury occurs.

Five years ago, scientists at URMC found that after a spinal cord injury, ATP floods into the injury site, killing off healthy and uninjured cells. This results in an expansion of the injury site and often worsens paralysis in the injured patient. Neurons in the spinal cord are particularly susceptible to ATP due to the presence of so-called "death receptors." Also known as P2X7, these receptors let ATP connect to the motor neurons, flooding the neurons with signals that lead to cell death.

Using this knowledge, the scientists tested the effect of injecting oxidized ATP into the spinal cord of injured rats. The oxidized ATP injection blocked the affect of ATP on the spinal cord injury. Furthermore, the rats were able to recover much of their limb function that had been lost due to the spinal cord injury. However, injecting oxidized ATP into a human spinal cord injury patient is not practical for several reasons. First, inserting a needle into an injured spinal cord is a precarious process that could result in further injury. Second, injecting oxidized ATP into the bloodstream is not possible due to its dangerous side effects on the human body.

The scientists' next step was to look for a compound that could be used in place of oxidized ATP. Given their knowledge about P2X7, the death receptor on motor neurons, they decided to look for a substance that could prevent ATP from attaching to P2X7 and be administered intravenously. Through a stroke of luck, the scientists discovered that the compound Brilliant Blue G (BBG) meets both these criteria. BBG is a dye commonly used in gel electrophoresis. It is structurally and functionally similar to FD&C blue dye No. 1, which as been approved for human consumption by the FDA since 1982. Due to this similarity, it is considered safe to inject BBG into the bloodstream.

When BBG was injected intravenously into rats with spinal cord injuries, the scientists found that secondary injury due to ATP was significantly reduced. In addition, the rats were able to heal to the point that they were able to walk again. Injured rats that did not receive the injection did not recover from their spinal cord injuries. One side effect of the BBG injection was a temporary slight blue tint to the rat's skin color.

Though these results are promising, much more research and testing is needed before this technique can be used in human clinical trials. The researchers are hopeful that new treatments for acute spinal cord injuries could be ready for human use within the next few years.

The results of the scientists' research were published online in the July 28, 2009 edition of the journal . Researchers who contributed to the study included Weiguo Peng, Maria L. Cotrina, Xiaoning Han, Hongmei Yu, Lane Bekar, Livnat Blum, Takahiro Takano, Guo-Feng Tia, Steven Goldman, and Maiken Nedergaard.

More to Explore

• Common Food Dye May Hold Promise in Treating Spinal Cord Injury
• Systemic administration of an antagonist of the ATP-sensitive receptor P2X7 improves recovery after spinal cord injury [abstract]

Last updated July 30, 2009 | Comments (4) | Permalink | Weekly News Update