Fig. 1

The role of extracellular matrix (ECM) in blood vessels. A Collagen, renowned for its toughness, provides mechanical support for blood vessels; B elastin imparts fibrous elasticity to blood vessels, rendering them highly adaptable to mechanical forces; C glycosaminoglycans, proteoglycans, and hyaluronic acid form protein–polysaccharide complexes, which can bind a large amount of water and provide viscoelasticity for blood vessels; D fibronectin and laminin are large multi-domain glycoproteins, which interact with other ECM proteins to form connections between the ECM and cells via integrins and transmit signals. ECM proteins can be degraded by proteases. Since most of the proteins found in ECM are substrates of matrix metalloproteinases (MMPs), the balance between MMPs and their endogenous inhibitors is critical for maintaining ECM stability