ATP6V1H Deficiency Impairs Bone Development through Activation of MMP9 and MMP13

• DOI: 10.1371/journal.pgen.1006481
• Publication Date: 2017-02-03T18:37:22Z
• Authors: Yihan Zhang; Haigen Huang; Gexin Zhao; Tadafumi Yokoyama; Hugo Vega; Yan Huang; Raman Sood; Kevin Bishop; Valerie Maduro; John Accardi; Camilo Toro; Cornelius F. Boer...; Karen Lyons; William A. Gahl; Xiaohong Duan; May Christine V. ...; Shuo Lin
• Keywords: Adult; 0301 basic medicine; Vacuolar Proton-Translocating ATPases; QH426-470; Mice; 03 medical and health sciences; Chondrocytes; Bone Density; 616; Matrix Metalloproteinase 13; Genetics; 2.1 Biological and endogenous factors; Animals; Humans; Aetiology; Zebrafish; Bone Development; Prevention; 3. Good health; Matrix Metalloproteinase 9; Musculoskeletal; Mutation; Osteoporosis; CRISPR-Cas Systems; Biotechnology; Developmental Biology; Research Article; Signal Transduction

ATP6V1H is a component of a large protein complex with vacuolar ATPase (V-ATPase) activity. We identified two generations of individuals in which short stature and osteoporosis co-segregated with a mutation in ATP6V1H. Since V-ATPases are highly conserved between human and zebrafish, we generated loss-of-function mutants in atp6v1h in zebrafish through CRISPR/Cas9-mediated gene knockout. Homozygous mutant atp6v1h zebrafish exhibited a severe reduction in the number of mature calcified bone cells and a dramatic increase in the expression of mmp9 and mmp13. Heterozygous adults showed curved vertebra that lack calcified centrum structure and reduced bone mass and density. Treatment of mutant embryos with small molecule inhibitors of MMP9 and MMP13 significantly restored bone mass in the atp6v1h mutants. These studies have uncovered a new, ATP6V1H-mediated pathway that regulates bone formation, and defines a new mechanism of disease that leads to bone loss. We propose that MMP9/MMP13 could be therapeutic targets for patients with this rare genetic disease.