A common SNP risk variant MT1-MMP causative for Dupuytren's disease has a specific defect in collagenolytic activity

Dupuytren's Disease (DD) is a common fibroproliferative disease of the palmar fascia. We previously identified a causal association with a non-synonymous variant (rs1042704, p.D273N) in MMP14 (encoding MT1-MMP). In this study, we investigated the functional consequences of this variant, and demonstrated that the variant MT1-MMP (MT1-N₂₇₃) exhibits only 17% of cell surface collagenolytic activity compared to the ancestral enzyme (MT1-D₂₇₃). Cells expressing both MT1-D₂₇₃ and MT1-N₂₇₃ in a 1:1 ratio, mimicking the heterozygous state, possess 38% of the collagenolytic activity compared to the cells expressing MT1-D₂₇₃, suggesting that MT1-N₂₇₃ acts in a dominant negative manner. Consistent with the above observation, patient-derived DD myofibroblasts with the alternate allele demonstrated around 30% of full collagenolytic activity detected in ancestral G/G genotype cells, regardless of the heterozygous (G/A) or homozygous (A/A) state. Small angle X-ray scattering analysis of purified soluble Fc-fusion enzymes allowed us to construct a 3D-molecular envelope of MT1-D₂₇₃ and MT1-N₂₇₃, and demonstrate altered flexibility and conformation of the ectodomains due to D₂₇₃ to N substitution. Taking together, rs1042704 significantly reduces collagen catabolism in tissue, which tips the balance of homeostasis of collagen in tissue, contributing to the fibrotic phenotype of DD. Since around 30% of the worldwide population have at least one copy of the low collagenolytic alternate allele, further investigation of rs1042704 across multiple pathologies is needed.