Paraplegia curable in the future? Scientists find key protein for spinal cord repair

New findings could bring advances in human medicine
A paraplegia is considered to be incurable. However, new therapeutic approaches are constantly being developed to restore the function of injured nerves. Duke University researchers in Durham, North Carolina have now found a key protein in the repair of injured spinal cord through experiments with zebrafish. The results of the research arouse hope, because the protein occurs in a similar form in humans. The results of the study were published in the renowned journal "Science".

Paraplegia due to spinal cord injury
The spinal cord is located in the bony spinal canal of the spine and together with the brain forms the central nervous system (CNS). Its task is inter alia in the communication between the brain and the internal organs as well as the skin and muscles. It is also responsible for monitoring motor skills and body movements. When the nerves in the spinal cord become injured by an accident, threaten permanent damage in the form of paraplegia. This is so far not curable, but the paralysis remains mostly lifelong.

Most of the physical restrictions on paraplegia persist throughout life. A recent zebrafish study raises new hope for recovery. (Image: cunaplus / fotolia.com)

Zebrafish succeed in self-healing
This is not true for zebrafish, according to a Duke University news release in Durham, North Carolina. If the spinal cord of the - also known as zebrafish - injured animals, they also show paralysis phenomena that resemble those of humans.

But unlike us, then begins a healing process in which so-called glial cells first bridge the gap between the ends of the separated nerve fibers, informs the university. Subsequently, nerve cells are created, through which the interruption is gradually closed.

Fish are cured after eight weeks
After about eight weeks, the new nerve tissue has filled the gap and the paralysis phenomena have completely disappeared. In mammals, however, among other things, the resulting scar tissue blocks a renewed growth of nerve cells and thus a linkage of the ends.

Kenneth Poss of Duke University is quoted in the communication as saying, "This is one of the most notable feats of natural regeneration." "Given the limited number of successful therapies available today for repairing lost tissue, we need to look at animals like zebrafish for new clues on how to stimulate regeneration," the scientist continues.

Researchers discover special protein molecules
But how does this extraordinary ability of zebrafish explain itself? To answer this question, a research team led by Kenneth Poss observed the animals during the regeneration process and came up with amazing results. The experts were able to identify seven specific genes that are responsible for the production of certain protein molecules in the event of spinal cord injury. One of these, CTGF (Connective Tissue Growth Factor), was formed in the glial cells, which in the first step of healing form the bridge between the severed nerve endings.

Man has similar protein
"We hypothesized that CTGF might be important as it was activated only in specific cells after injury," co-author Mayssa Mokalled said. A similar protein, whose structure is only ten percent different from zebrafish CTGF, also occurs in humans. The researchers used the human form of CTGF in the animals with spinal cord injuries and realized that in this case too an intensification of the regeneration of the nerve tissue began.

"The previously paralyzed fish were swimming in the aquarium again. The effect of the protein is impressive, "says Mokalled. "I do not think CTGF is the whole secret, but we have something in it that helps us to achieve regeneration," says Poss. Now, experiments with mice are planned to find out at what time and in what cell type CTGF is produced. (No)