| First Author | Liang T | Year | 2022 |
| Journal | Sci Rep | Volume | 12 |
| Issue | 1 | Pages | 16477 |
| PubMed ID | 36183038 | Mgi Jnum | J:332462 |
| Mgi Id | MGI:7345114 | Doi | 10.1038/s41598-022-20684-9 |
| Citation | Liang T, et al. (2022) Enamel defects in Acp4(R110C/R110C) mice and human ACP4 mutations. Sci Rep 12(1):16477 |
| abstractText | Human ACP4 (OMIM*606362) encodes a transmembrane protein that belongs to histidine acid phosphatase (ACP) family. Recessive mutations in ACP4 cause non-syndromic hypoplastic amelogenesis imperfecta (AI1J, OMIM#617297). While ACP activity has long been detected in developing teeth, its functions during tooth development and the pathogenesis of ACP4-associated AI remain largely unknown. Here, we characterized 2 AI1J families and identified a novel ACP4 disease-causing mutation: c.774_775del, p.Gly260Aspfs*29. To investigate the role of ACP4 during amelogenesis, we generated and characterized Acp4(R110C) mice that carry the p.(Arg110Cys) loss-of-function mutation. Mouse Acp4 expression was the strongest at secretory stage ameloblasts, and the protein localized primarily at Tomes' processes. While Acp4 heterozygous (Acp4(+/R110C)) mice showed no phenotypes, incisors and molars of homozygous (Acp4(R110C/R110C)) mice exhibited a thin layer of aplastic enamel with numerous ectopic mineralized nodules. Acp4(R110C/R110C) ameloblasts appeared normal initially but underwent pathology at mid-way of secretory stage. Ultrastructurally, sporadic enamel ribbons grew on mineralized dentin but failed to elongate, and aberrant needle-like crystals formed instead. Globs of organic matrix accumulated by the distal membranes of defective Tomes' processes. These results demonstrated a critical role for ACP4 in appositional growth of dental enamel probably by processing and regulating enamel matrix proteins around mineralization front apparatus. |
