S100 proteins: a new frontier in fibromyalgia research.

Fibromyalgia (FM) is a chronic condition that causes widespread pain, fatigue, and other symptoms that significantly affect quality of life. The underlying mechanisms of fibromyalgia involve both the immune system and the central nervous system. It has been proposed that changes in multiple ascending and descending pathways in the central nervous system may contribute to increased pain sensitivity in individuals with this condition. Recent research has identified S100 proteins as a new area of interest in fibromyalgia studies. These proteins are a group of small molecular weight proteins involved in inflammation and various functions inside and outside of cells, and they may play a critical role in the development and progression of FM. Although S100B has been the most studied in FM patients, other studies have reported that S100A7, S100A8, S100A9, and S100A12 may also be useful as potential biomarkers or for a deeper understanding of FM pathophysiology. The potential role of S100 proteins in the pathophysiology of fibromyalgia could be mediated by RAGE and TLR4, which signal through JNK, ERK, and p38 to activate AP-1 and NF-κB and induce the release of proinflammatory cytokines, thereby producing the inflammation, fatigue, and chronic pain characteristic of fibromyalgia. To gain new perspectives on targeted therapeutic approaches, it is crucial to understand how S100 proteins could impact the pathophysiology of fibromyalgia. This review examines the potential role of S100 proteins in fibromyalgia and their impact on improving our comprehension of the condition, as well as facilitating further research on this interesting topic.