The muscle–intervertebral disc interaction mediated by L-BAIBA modulates extracellular matrix homeostasis and PANoptosis in nucleus pulposus cells

Upon engaging in physical activity, skeletal muscle synthesizes myokines, which not only facilitate crosstalk with various organs, including the brain, adipose tissue, bone, liver, gut, pancreas, and skin but also promote intramuscular signaling. Crosstalk is vital for maintaining various physiological processes. However, the specific interactions between skeletal muscle and intervertebral discs remain largely unexplored. β-Aminoisobutyric acid (BAIBA), an exercise-induced myokine and a metabolite of branched-chain amino acids in skeletal muscle, has emerged as a key player in this context. Our study demonstrated that exercise significantly elevates BAIBA levels in skeletal muscle, plasma, and nucleus pulposus (NP) tissues. Moreover, exercise enhances extracellular matrix (ECM) synthesis in NP tissues and upregulates L-BAIBA synthase in skeletal muscle. Both in vivo and in vitro evidence revealed that L-BAIBA impedes PANoptosis and ECM degradation in NP cells by activating the AMPK/NF-κB signaling pathway. These findings suggest that exercise, coupled with the resulting increase in L-BAIBA, may serve as an effective intervention to decelerate the progression of intervertebral disc degeneration (IDD). Consequently, L-BAIBA, which originates from skeletal muscle, is a promising new therapeutic approach for IDD. Intervertebral disc degeneration affects many people globally. Researchers investigated how exercise and a muscle-produced molecule, L-BAIBA, can slow IDD. They used human tissue samples, cell cultures, and rat models to study how exercise affects IDD and how L-BAIBA protects disc cells. The study combined lab and animal research, using human disc tissues and rats to understand disc degeneration and exercise effects. They found exercise increases L-BAIBA production, which benefits disc cells by promoting essential disc components and reducing cell death, a degeneration contributor. This could lead to non-invasive IDD treatments using the body’s exercise responses. The results showed exercise and L-BAIBA improved disc health by increasing essential disc components and reducing cell death. They suggest L-BAIBA could be a new IDD treatment, using exercise benefits at a molecular level. This summary was initially drafted using artificial intelligence, then revised and fact-checked by the author.