Functional analysis of a hypomorphic allele shows that MMP14 catalytic activity is the prime determinant of the Winchester syndrome phenotype

Abstract

Winchester syndrome (WS, MIM #277950) is an extremely rare autosomal recessive skeletal dysplasia characterized by progressive joint destruction and osteolysis. To date, only one missense mutation in MMP14, encoding the membrane-bound matrix metalloprotease 14, has been reported in WS patients. Here, we report a novel hypomorphic MMP14 p.Arg111His (R111H) allele, associated with a mitigated form of WS. Functional analysis demonstrated that this mutation, in contrast to previously reported human and murine MMP14 mutations, does not affect MMP14’s transport to the cell membrane. Instead, it partially impairs MMP14’s proteolytic activity. This residual activity likely accounts for the mitigated phenotype observed in our patients. Based on our observations as well as previously published data, we hypothesize that MMP14’s catalytic activity is the prime determinant of disease severity. Given the limitations of our in vitro assays in addressing the consequences of MMP14 dysfunction, we generated a novel mmp14a/b knockout zebrafish model. The fish accurately reflected key aspects of the WS phenotype including craniofacial malformations, kyphosis, short-stature and reduced bone density owing to defective collagen remodeling. Notably, the zebrafish model will be a valuable tool for developing novel therapeutic approaches to a devastating bone disorder.

Zebrafish Models for Human Skeletal Disorders

“…These are the dysmorphologies generated by the altered migration of neural crest cells in ids morphants or CRISPR/Cas9 mutant ( Moro et al, 2010 ; Bellesso et al, 2018 ) or several phenotypes shown by morphants and TALEN-edited mutants of gnptab ( Flanagan-Steet et al, 2009 , 2016 , 2018 ; Petrey et al, 2012 ). Finally, the morpholino downregulation of zebrafish lmna gene or the transgenic overexpression of mutant human alleles of LMNA ( Koshimizu et al, 2011 ) has been proposed as models of mandibuloacral dysplasia, whereas the CRISPR/Cas9 editing of mmp14 ( De Vos et al, 2018 ) has been proposed as a model of MONA syndrome.…”

Different roles of matrix metalloproteinase 2 in osteolysis of skeletal dysplasia and bone metastasis (Review)

“…Both of them are autosomal recessive disorders characterized by highly similar phenotypes of progressive multicentric osteolysis and arthritis. Although not directly associated with MMP2 mutation, the pathogenesis of WS is thought to be linked with deficient MMP2 activity, since intact function of MMP14 is critical for activation of MMP2 ( 33 ).…”

Genetic regulation of linear growth

“…MMPs have been shown to play an integral role in regulating chondrocyte proliferation, extracellular matrix degradation, and release of extracellular matrix proteins [26]. However, there have not yet been reports of mutations in MMP-encoding genes causing skeletal defects in humans, although there has been a case report of Winchester syndrome due to a hypomorphic mutation in MMP14 [27]. The precise functions of these enzymes have not been wellestablished but many family members were identified by GWA studies to be associated with height variation ( ADAM28, ADAMTS19, ADAMTS2, ADAMTS3, ADAMTS6, ADAMTSL1, ADAMTSL3 ) suggesting a possible role in linear growth.…”