Tissue Inhibitors of Metalloproteinases (TIMPs)

Tissue inhibitors of metalloproteinases (TIMPs) are natural inhibitors of matrix metalloproteinases (MMPs) found in most tissues and body fluids. By inhibiting MMP activity, they participate in tissue remodeling of the extracellular matrix (ECM). The balance between MMP and TIMP activities is involved in both normal and pathological events such as wound healing, tissue remodeling, angiogenesis, invasion, tumorigenesis, and metastasis. (Lambert et al. Crit Rev. Oncol Hematol 2004; 49:187–198).

In addition to their MMP inhibition activity, recent studies have suggested that TIMPs themselves may have roles independent of MMPs that include direct modulation of cell growth and differentiation. TIMPs usually form a 1:1 enzymeinhibitor complex with their MMP counterparts. Currently four TIMPs have been identified in humans. They are homologous proteins of 21–29 kDa in size and consist of two domains, an N-terminal inhibitory domain and a C-terminal binding/mediation domain. (Nagase, H. Arthritis Res 2002; 4:S51–S61).