Photobiomodulation of extracellular matrix enzymes in human nucleus pulposus cells as a potential treatment for intervertebral disk degeneration

Intervertebral disc (IVD) degeneration is associated with imbalances between catabolic and anabolic responses, regulated by extracellular matrix (ECM)-modifying enzymes such as matrix metalloproteinases (MMPs) and their endogenous tissue inhibitors of metalloproteinases (TIMPs). Potential contributing factors, such as interleukin (IL)-1β and tumor necrosis factor (TNF)-α, derived from infiltrated, activated macrophages within IVD tissues, can trigger abnormal production of ECM-modifying enzymes and progression of IVD degeneration. Novel therapies for regulating ECM-modifying enzymes can prevent or ameliorate IVD degeneration. Photobiomodulation (PBM), known to regulate wound repair, exhibits regenerative potential by modulating biological molecules. This study examined the effects of PBM, administered at various wavelengths (630, 525, and 465 nm) and energy densities (16, 32, and 64 J/cm 2 ), on the production of ECM-modifying enzymes in replicated degenerative IVD. Our results showed that PBM selectively inhibited the production of ECM-modifying enzymes in a dose- and wavelength-dependent manner, suggesting that it could be a novel tool for treating symptomatic IVD degeneration.