Collagen fibrils and associated extracellular matrix proteoglycans

Collagen fibrils and associated extracellular matrix (ECM) proteoglycans form the fundamental structural scaffold of the interstitial matrix in vertebrate tissues [Lodish et al., Molecular Cell Biology]. Collagen fibrils, predominantly composed of fibrillar collagens like Type I and III, provide the necessary tensile strength to tissues, while associated small leucine-rich proteoglycans (SLRPs), such as decorin and biglycan, decorate the fibril surface to regulate diameter and spacing [Nature Reviews Molecular Cell Biology, 2006]. Beyond their structural role, these components act as dynamic regulators of cell behavior by sequestering growth factors like TGF-beta and modulating mechanotransduction pathways [Journal of Cell Science, 2010]. Dysregulation of this complex is a hallmark of various pathologies, including systemic sclerosis, pulmonary fibrosis, and the desmoplastic response in solid tumors, which can physically impede the penetration of chemotherapeutic agents [Nature Reviews Cancer, 2004]. Therapeutic interventions often focus on either degrading excess collagen using specialized enzymes or inhibiting the biosynthetic pathways and cross-linking mechanisms that lead to pathological ECM accumulation [NEJM, 2014; FDA Xiaflex Label].

Other names

Extracellular matrixCollagen-proteoglycan complexFibrillar collagenSLRP-associated collagen

Drugs targeting this complex act through enzymatic lysis of collagen peptide bonds, inhibition of collagen synthesis, or suppression of extracellular matrix cross-linking [FDA Xiaflex Label; NEJM 2014].