Matrix metalloproteinase and tissue inhibitor of metalloproteinase responses to muscle damage after eccentric exercise

High-intensity eccentric exercise is known to induce muscle damage leading to inflammatory responses and extracellular matrix (ECM) degradation. These degradation processes involve enzymes such as matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs). MMPs are calcium and zinc-dependent proteolytic enzymes that play a role in ECM degradation and recruitment of inflammatory and myogenic cells into the damaged site. In contrast, TIMPs inhibit MMP-induced ECM degradation to maintain normal homeostasis in ECM. Recently, several studies have examined the process of muscle remodeling and the roles of ECM, MMPs, and TIMPs in exercise-induced muscle damage. However, the results of these studies are not inconsistent. In the present mini-review, we will discuss the responses of MMP and TIMP to eccentric exercise based on the literature review.