title: Dihydroorotate dehydrogenase depletion hampers mitochondrial function and osteogenic differentiation in osteoblasts.
abstract: Mutation of the dihydroorotate dehydrogenase (DHODH) gene is responsible for Miller syndrome, which is characterized by craniofacial malformations with limb abnormalities. We previously demonstrated that DHODH was involved in forming a mitochondrial supercomplex and that mutated DHODH led to protein instability, loss of enzyme activity, and increased levels of reactive oxygen species in HeLa cells. To explore the etiology of Miller syndrome in more detail, we investigated the effects of DHODH inhibition in the cells involved in skeletal structure. Dihydroorotate dehydrogenase in MC3T3-E1 cells derived from mouse calvaria osteoblast precursor cells was knocked down by specific small interfering RNAs (siRNAs), and cell proliferation, ATP production, and expression of bone-related genes were investigated in these cells. After depletion of DHODH using specific siRNAs, inhibition of cell proliferation and cell cycle arrest occurred in MC3T3-E1 cells. In addition, ATP production was reduced in whole cells, especially in mitochondria. Furthermore, the levels of runt-related transcription factor 2 (Runx2) and osteocalcin (Ocn) mRNAs were lower in DHODH siRNA-treated cells compared with controls. These data suggest that depletion of DHODH affects the differentiation and maturation of osteoblasts. This study shows that mitochondrial dysfunction by DHODH depletion in osteoblasts can be directly linked to the abnormal bone formation in Miller syndrome.
authors.affiliation: Department of Pediatric Dentistry, Graduate School of Dental Science, Kyushu University, Fukuoka, Japan.|Department of Clinical Chemistry and Laboratory Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.|Department of Orthodontics and Craniofacial Biology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, the Netherlands.|Department of Pediatric Dentistry, Guangdong Provincial Stomatological Hospital, Southern Medical University, Guangzhou, China.
authors.forename: JingXian
authors.initials: J
authors.lastname: Fang
authors.affiliation: Department of Pediatric Dentistry, Graduate School of Dental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Haruyoshi
authors.identifier: 0000-0003-1138-3943
authors.initials: H
authors.lastname: Yamaza
authors.affiliation: Department of Clinical Chemistry and Laboratory Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Uchiumi
authors.affiliation: Department of Pediatric Dentistry, Graduate School of Dental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Hoshino
authors.affiliation: Department of Pediatric Dentistry, Graduate School of Dental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Masuda
authors.affiliation: Department of Pediatric Dentistry, Graduate School of Dental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Hirofuji
authors.affiliation: Department of Orthodontics and Craniofacial Biology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, the Netherlands.
authors.forename: Frank A D T G
authors.initials: FA
authors.lastname: Wagener
authors.affiliation: Department of Clinical Chemistry and Laboratory Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Dongchon
authors.initials: D
authors.lastname: Kang
authors.affiliation: Department of Pediatric Dentistry, Graduate School of Dental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Nonaka
mesh_terms: D000015:Abnormalities, Multiple / Q000201:enzymology*; D000818:Animals; D002454:Cell Differentiation; D002478:Cells, Cultured; D000090722:Dihydroorotate Dehydrogenase; D006367:HeLa Cells; D006801:Humans; D017880:Limb Deformities, Congenital / Q000201:enzymology*; D008342:Mandibulofacial Dysostosis / Q000201:enzymology*; D051379:Mice; D008844:Micrognathism / Q000201:enzymology*; D008928:Mitochondria; D010006:Osteoblasts; D010012:Osteogenesis; D044925:Oxidoreductases Acting on CH-CH Group Donors / Q000378:metabolism*
chemical_list: D000090722:Dihydroorotate Dehydrogenase; D044925:Oxidoreductases Acting on CH-CH Group Donors
keywords: MC3T3-E1 cells; Miller syndrome; mitochondria; osteogenesis