microRNA Plays Crucial Role in Nerve Pain

A recent study has found a microRNA molecule, miR-30c-5p, that contributes to nerve pain in rats and humans. By regulating protein production and gene activity, microRNAs play an essential role in the body, where they also help to control cancers and other diseases. The tiny molecules often pair with messenger RNA (mRNA) to limit production of various proteins.

From the pharmacology department at the University of Cantabria in Santander, Spain comes the study on miR-30c-5p, which suppresses production of the TGF-beta protein. This protein is important for reducing pain responses in nerve cells in mice, rats and people. The scientists found that injured rats had more of the RNA in their blood, which correlated to pain sensitivity. They also noticed that people with nerve pain have raised amounts of miR-30c-5p in their blood and spinal fluid. Next, they injected rats with either miR-30c-5p or an imposter RNA and tested pain sensitivity. The rats that got the imposter had normal pain responses, while the others became much more sensitive to cold. Then, these pain sensitive rats were injected with with yet another RNA, which binds to miR-30c-5p and prevents its further interaction. These rats then showed normal pain responses once again.

Blocking RNA spread throughout spinal cord section, under fluorescence microscope.

However, just blocking the RNA isn't a viable pain-treatment option, since the molecule plays too many other biological roles. Testing blood levels for miR-30c-5p may be a good indicator of pain for doctors, though. No other biological indicator is known that can distinguish between nerve pain and pain with other causes, such as inflammation.