stromelysiner

Stromelysiner are a subgroup within the matrix metalloproteinases (MMPs) that specialize in the degradation and remodeling of the extracellular matrix. The best characterized members are stromelysin-1 and stromelysin-2. Like other MMPs, they are zinc-dependent endopeptidases secreted as inactive proenzymes and activated by proteolytic processing.

They share a modular structure that includes a catalytic domain containing a zinc ion and a hemopexin-like C-terminal domain, which mediates substrate recognition and interactions with inhibitors and other proteins. This architecture enables them to interact with a variety of matrix components and regulatory molecules.

Their substrates include proteoglycans, laminin, fibronectin, and non-fibrillar collagens, supporting cell migration, tissue remodeling, and wound repair. They can also process cytokines and growth factors, influencing local signaling and tissue responses.

Stromelysiner are produced by several cell types, including fibroblasts, macrophages, and epithelial cells. Their expression is upregulated by inflammatory stimuli such as interleukins and TNF-alpha. Activity is tightly regulated by tissue inhibitors of metalloproteinases (TIMPs); imbalances can shift the balance toward excessive matrix breakdown or insufficient remodeling.

Physiological roles encompass normal development, angiogenesis, and connective tissue remodeling during healing. Pathologically, dysregulated stromelysin activity has been linked to inflammatory diseases such as arthritis and to cancer progression, where matrix degradation facilitates invasion and metastasis.

Research and therapeutic interest focus on modulating stromelysin activity to control matrix remodeling. Clinical applications have faced challenges due to redundancy within the MMP family and side effects, but stromelysiner remain important for understanding tissue dynamics and disease processes.