Circular RNA circ-4099 is induced by TNF-α and regulates ECM synthesis by blocking miR-616-5p inhibition of Sox9 in intervertebral disc degeneration

Abstract

Spinal disease: Circular RNA linked to disc degeneration A circular RNA molecule helps protect against degenerative disc disease. Hua Wang and coworkers from Sun Yat-Sen University in Guangzhou, China, examined whether circular RNAs, regulatory molecules that take the form of closed RNA loops, contribute to intervertebral disc degeneration, a condition in which connective tissue in the spine breaks down over time, causing back pain and weakness. They found 72 circular RNAs that were either significantly over- or under-expressed in the inner core tissue of intervertebral discs from patients with this condition. They showed that one of these circular RNAs, circ-4099, increased the production of key cartilage proteins. This RNA also blocked the activity of another non-circular regulatory RNA that normally inhibits a molecular pathway needed for proper cartilage formation. Enhancing the activity of this protective molecule could help treat degenerative disc disease.