Matrilin (MATN)

Matrilins are a family of four oligomeric extracellular matrix (ECM) proteins (Matrilin-1 to -4) that serve as essential adaptors for the assembly and stabilization of the ECM network [11, 19]. They are characterized by a modular structure containing von Willebrand factor A (vWFA) domains, epidermal growth factor (EGF)-like domains, and a C-terminal coiled-coil domain that facilitates oligomerization into homo- and hetero-multimers [1, 13]. Matrilin-1 and Matrilin-3 are predominantly expressed in cartilage, where they interconnect collagen II/IX fibrils and aggrecan, while Matrilin-2 and -4 have a broader distribution in various connective tissues, including the basement membrane and peripheral nerves [2, 11]. In disease, mutations in the MATN3 gene are a primary cause of skeletal dysplasias such as Multiple Epiphyseal Dysplasia (MED) and are strongly associated with early-onset osteoarthritis [7, 21]. Matrilin-2 has been implicated in neuroinflammation and cancer progression, acting as a damage-associated molecular pattern (DAMP) that signals through TLR4 [6, 10]. Although no drugs targeting matrilins are currently FDA-approved, they are actively being investigated as therapeutic targets for cartilage regeneration, anti-angiogenic therapy, and as diagnostic biomarkers for degenerative joint diseases [30, 31]. Experimental strategies include the use of recombinant matrilin proteins to restore matrix function or small molecules to modulate their signaling interactions with TGF-beta and BMP pathways [8, 31].

Other names

MATN1MATN2MATN3MATN4Cartilage matrix proteinCMP

Matrilins function as adaptor proteins that bridge collagen fibrils and proteoglycans to maintain ECM structural integrity. Matrilin-3 specifically acts as a BMP-2 antagonist to inhibit chondrocyte hypertrophy and induces IL-1 receptor antagonists to suppress inflammation. Matrilin-1 inhibits angiogenesis by blocking growth factor-stimulated endothelial cell proliferation.