Impaired osteogenesis in Menkes disease-derived induced pluripotent stem cells.
BACKGROUND
Bone abnormalities, one of the primary manifestations of Menkes disease (MD), include a weakened bone matrix and low mineral density. However, the molecular and cellular mechanisms underlying these bone defects are poorly understood.


METHODS
We present in vitro modeling for impaired osteogenesis in MD using human induced pluripotent stem cells (iPSCs) with a mutated ATP7A gene. MD-iPSC lines were generated from two patients harboring different mutations.


RESULTS
The MD-iPSCs showed a remarkable retardation in CD105 expression with morphological anomalies during development to mesenchymal stem cells (MSCs) compared with wild-type (WT)-iPSCs. Interestingly, although prolonged culture enhanced CD105 expression, mature MD-MSCs presented with low alkaline phosphatase activity, reduced calcium deposition in the extracellular matrix, and downregulated osteoblast-specific genes during osteoblast differentiation in vitro. Knockdown of ATP7A also impaired osteogenesis in WT-MSCs. Lysyl oxidase activity was also decreased in MD-MSCs during osteoblast differentiation.


CONCLUSIONS
Our findings indicate that ATP7A dysfunction contributes to retardation in MSC development and impairs osteogenesis in MD.
Department of Biological Science, Korea Advanced Institute of Science Technology (KAIST), Daejeon, 305-701, Republic of Korea. kdkd86@kaist.ac.kr.
Dongkyu
D
Kim
Department of Biological Science, Korea Advanced Institute of Science Technology (KAIST), Daejeon, 305-701, Republic of Korea. euny519@kaist.ac.kr.
Jieun
J
Choi
Department of Biological Science, Korea Advanced Institute of Science Technology (KAIST), Daejeon, 305-701, Republic of Korea. hankm88@kaist.ac.kr.
Kyu-Min
KM
Han
Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, South Korea. bhlee@amc.seoul.kr.
Beom Hee
BH
Lee
Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, South Korea. jhc@amc.seoul.kr.
Jin-Ho
JH
Choi
Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, South Korea. hwyoogene@gmail.com.
Han-Wook
HW
Yoo
Department of Biological Science, Korea Advanced Institute of Science Technology (KAIST), Daejeon, 305-701, Republic of Korea. ymhan57@kaist.ac.kr.
Yong-Mahn
YM
Han
D000251:Adenosine Triphosphatases / Q000235:genetics; D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D027682:Cation Transport Proteins / Q000235:genetics; D002478:Cells, Cultured; D000073840:Copper-Transporting ATPases; D000071063:Endoglin; D005109:Extracellular Matrix / Q000378:metabolism; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000166:cytology / Q000378:metabolism* / Q000637:transplantation; D007223:Infant; D007231:Infant, Newborn; D007706:Menkes Kinky Hair Syndrome / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D009154:Mutation; D010012:Osteogenesis; D008249:Protein-Lysine 6-Oxidase / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism
D015703:Antigens, CD; D027682:Cation Transport Proteins; C064206:ENG protein, human; D000071063:Endoglin; D011956:Receptors, Cell Surface; D008249:Protein-Lysine 6-Oxidase; D000251:Adenosine Triphosphatases; C081184:ATP7A protein, human; D000073840:Copper-Transporting ATPases