The hopes of many quadriplegics (like me) and otherwise injured individuals have been dashed since Korean stem-cell researcher Hwang Woo-suk, who claimed to be on track for curing spinal cord injuries among other ailments, turned out to be an apparent fraud. But I never hung all of my hopes on Hwang or stem-cell research.
That’s because scientists who study spinal cord injury, or SCI, know that it won’t be stem cells or any other single therapy that will cure paralysis.
At the Society for Neuroscience conference in November, I was surrounded by the top researchers in the country dedicated to curing SCI. Not one of them touted stem cells as the only way to a cure.
I should know, because I was on a focused mission on that trip to Washington, D.C. With no ability to move below my shoulders, my travels are extremely limited. My goal was to swiftly identify, isolate and interrogate the researchers who were most likely to discover treatments for paralysis. I wanted to know which labs were closest to bringing an effective therapy into human trials. I had some ideas, but preferred hard evidence.
I had done significant research in preparation for my trip, so my list of primary targets was small: The Tuszynski Lab at the University of California at San Diego and representatives from Acorda Therapeutics. They were both working on treatments that combined multiple therapies. According to my intelligence gathering, a combination approach is my best bet — regardless of the hype surrounding stem cells as a cure-all.
World-renowned SCI researcher Dr. Wise Young reassured me that combination therapies are going to be key for curing spinal cord injuries. At an intimate open house he convened during the conference, he updated families living with paralysis on the latest progress in research.
A combination therapy, he said, is likely the best chance for a paralysis cure because the injury itself is so complex.
A healthy spinal cord works like this: Messages travel from the brain to the body through a network of neurons in the spinal cord. Neurons connect at synapses, where neuronal extensions called axons and dendrites meet. The messages are transmitted across synapses by small electrical impulses, requiring the axons to be insulated in a white, fatty substance called Myelin.
A spinal cord injury disrupts the flow of information by damaging the nerves. The damage initiates a cellular cascade of events that causes neighboring nerve cells to commit suicide, and then this unhealthy cycle of violence repeats. This process can continue for up to two weeks, leaving a paralyzing Lesion in its place and causing the axons of surviving neurons to lose their insulation.
An early therapy, methylprednisolone, focused on limiting this damage and saw some success in patients who received the drug within hours after injury. But researchers didn’t have the same success with longer-term injuries (I sustained a contusion to my third vertebra in a car accident nine years ago when I was 16).
Researchers have also focused on restoring function by remyelinating spared axons, bridging the injury site by transplanting nerve grafts, and overcoming environmental cues that inhibit nerve Regeneration, all to varying degrees of success.
Young’s approach is a five-part combination strategy involving a bridging substrate, growth inhibitor blockers, remyelinating substances, molecules that guide axons to reconnect to their proper targets and something that would entice the axons to grow out of and beyond the bridging substrate. Scientists presented similar strategies recently at the International Spinal Cord Injury Treatments and Trials Symposium in Hong Kong.
Many of the researchers I spoke to at the neuroscience conference were focusing on single, rather than combination, therapies. I was disappointed at first, but I soon realized that researchers finally have all the pieces they need — some cruder than others — and all that remains is for someone to put them together in the right order. And a few labs are attempting just that.
Researchers in the Tuszynski Lab confirmed they were planning to test combination therapies in primates, as noted in a grant application.
Acorda applied for a grant to test a promising combination therapy in rodents. H. David Shine’s lab at Baylor University filed a similar grant application.
My mission, it seems, was a success. Call me an optimist, but the Hwang Woo-suk debacle is not a disaster for people living with spinal cord injuries.
By Steven Edwards