FASTER, PLEASE: Scientists find key protein for spinal cord repair.

Of dozens of genes strongly activated by injury, seven coded for proteins that are secreted from cells. One of these, called CTGF or connective tissue growth factor, was intriguing because its levels rose in the supporting cells, or glia, that formed the bridge in the first two weeks following injury.

“We were surprised that it was expressed in only a fraction of glial cells after the injury. We thought that these glial cells and this gene must be important,” said lead author Mayssa Mokalled, a postdoctoral fellow in Poss’s group. Indeed, when they tried deleting CTGF genetically, those fish failed to regenerate.

Humans and zebrafish share most protein-coding genes, and CTGF is no exception. The human CTGF protein is nearly 90% similar in its amino acid building blocks to the zebrafish form. When the team added the human version of CTGF to the injury site in fish, it boosted regeneration and the fish swam better by two weeks after the injury.

“The fish go from paralyzed to swimming in the tank. The effect of the protein is striking,” Mokalled said.

The second half of the CTGF protein seems to be the key to the healing, the group found. It’s a large protein, made of four smaller parts, and it has more than one function. That might make it easier to deliver and more specific as a therapy for spinal injuries.

Like I said, faster, please.