Growth Factor Could Pave Way for New Painkiller

Neurobiology of Disease.

A new type of painkiller may be on the way due to a recent breakthrough, according to a study published in

Investigators from The University of Nottingham wanted to explore vascular endothelial growth factor (VEGF), a signal protein that could lead the way to a new type of painkiller. Currently, VEGF controls the regrowth of blood vessels in damaged tissue. It is also used in eye diseases and other various illnesses where abnormal blood vessel growth is common. When used in cancer, VEGF blocks the formation of new blood cells that would otherwise provide oxygen and nutrients to tumors.

In 2002, the researchers learned VEGF appears in 2 forms and work as a switch — one activates the growth of blood vessels and the other that blocks their growth.

The researchers showed in their study that the 2 forms have opposite effects on pain in their study of 64 adult rats and mice (with 24 matched controls). The animals were eased into their testing environment and not probed for at least 15 minutes while they adjusted. Nociceptive behaviors were determined in the mice after various doses of treatments. However, the characteristics and distribution of VEGF sensitive affterents are not fully known in any species. The researchers noted bias was unavoidable, but only was brought to their attention in post-hoc analysis.

The researchers note that both the regrowth of blood cells and the control of blood cells types of VEGF are important for pain modulation in normal conditions as well as sensory neuropathy.

“Although differential expression of several alternatively spliced growth factors has been reported after peripheral nerve injury, and injured peripheral neurons show altered RNA splicing, control of pain through targeting of alternative RNA splicing has not been previously reported,” the authors wrote. “We have shown, for the first time, that peripheral axotomy activates changes in alternative RNA splicing in the area of damage, where mediators in the local environment can profoundly affect neuronal properties, possibly through transient receptor potential vanilloid 1 activation on sensory nerve fibers, as well as in the damaged neurons themselves.”

In the future, the researchers plan to investigate this protein’s effects in humans. They believe the compounds could form the guidelines to new drugs for human clinical trials.