Extracellular matrix substrates of MSC-secreted matrix metalloproteinases (ECM substrates)

Extracellular matrix (ECM) substrates of mesenchymal stem cell (MSC)-secreted matrix metalloproteinases (MMPs) represent a complex network of structural and functional proteins, including various types of collagen, fibronectin, laminin, and elastin (Yue, 2014, J Carcinog Mutagen). Mesenchymal stem cells actively secrete specific MMPs, such as MMP-1, MMP-2, and MMP-9, to proteolytically modify these substrates, which is a fundamental requirement for MSC migration, tissue infiltration, and the dynamic remodeling of the cellular microenvironment (Mannello et al., 2006, Stem Cells). This interaction is critical in physiological processes like wound healing and bone regeneration, where the controlled breakdown of the ECM allows for tissue reorganization and the release of bioactive molecules (Almalki and Agrawal, 2016, Stem Cells International). In pathological conditions such as cancer metastasis or chronic fibrosis, the dysregulation of this MMP-substrate axis leads to basement membrane degradation and excessive tissue scarring (Overall and Kleifeld, 2006, Nature Reviews Cancer). While the ECM substrates themselves are generally structural components rather than direct drug targets, the enzymes that degrade them (MMPs) have been the focus of extensive therapeutic development. However, clinical trials for MMP inhibitors like Marimastat have often failed due to a lack of selectivity and the development of musculoskeletal syndrome, highlighting the complexity of targeting these interactions (Coussens et al., 2002, Science).

Other names

Extracellular matrix componentsECM proteinsMMP substratesMesenchymal stem cell secretome substratesConnective tissue proteins

Proteolytic degradation of structural proteins by matrix metalloproteinases (MMPs) to facilitate tissue remodeling, cell motility, and the release of sequestered growth factors.