Characterization of osteoclasts from patients harboring a G215R mutation in ClC-7 causing autosomal dominant osteopetrosis type II
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Characterization of osteoclasts from patients harboring a G215R mutation in ClC-7 causing autosomal dominant osteopetrosis type II. / Henriksen, Kim; Gram, Jeppe; Schaller, Sophie; Dahl, Bjarne H; Dziegiel, Morten Hanefeld; Bollerslev, Jens; Karsdal, Morten A.
In: American Journal of Pathology, Vol. 164, No. 5, 05.2004, p. 1537-45.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - Characterization of osteoclasts from patients harboring a G215R mutation in ClC-7 causing autosomal dominant osteopetrosis type II
AU - Henriksen, Kim
AU - Gram, Jeppe
AU - Schaller, Sophie
AU - Dahl, Bjarne H
AU - Dziegiel, Morten Hanefeld
AU - Bollerslev, Jens
AU - Karsdal, Morten A
PY - 2004/5
Y1 - 2004/5
N2 - Autosomal dominant osteopetrosis II (ADOII) is a relatively benign disorder caused by a missense mutation in the ClCN7 gene. In this study, we characterize the osteoclasts from patients with ADOII, caused by a G215R mutation, and investigate the effect on osteoclast function in vitro. Osteoclasts from ADOII patients and healthy age- and sex-matched controls, were used to evaluate osteoclastogenesis, cell fusion, acidification, and resorptive activity. ADOII osteoclasts in vivo have increased number and size. However, in vitro we observed no significant changes in the osteoclast formation rate, the morphology, and the expression of markers, such as cathepsin K and tartrate-resistant acid phosphatase. When mature ADOII osteoclasts were investigated on mineralized bone, they degraded the bone material, however only to 10 to 20% of the level in controls. We show by acridine orange, that the reduced chloride transport leads to reduced acidification. We show that the residual activity is sensitive to inhibitors of cathepsins and chloride channels, confirming that resorption is reduced but present. In conclusion, this is the first functional in vitro study of human ADOII osteoclasts. We show normal osteoclastogenesis in ADOII osteoclasts. However, the residual activity of the ClC-7 channel in ADOII osteoclasts does not allow sufficient acidification and thereby resorption.
AB - Autosomal dominant osteopetrosis II (ADOII) is a relatively benign disorder caused by a missense mutation in the ClCN7 gene. In this study, we characterize the osteoclasts from patients with ADOII, caused by a G215R mutation, and investigate the effect on osteoclast function in vitro. Osteoclasts from ADOII patients and healthy age- and sex-matched controls, were used to evaluate osteoclastogenesis, cell fusion, acidification, and resorptive activity. ADOII osteoclasts in vivo have increased number and size. However, in vitro we observed no significant changes in the osteoclast formation rate, the morphology, and the expression of markers, such as cathepsin K and tartrate-resistant acid phosphatase. When mature ADOII osteoclasts were investigated on mineralized bone, they degraded the bone material, however only to 10 to 20% of the level in controls. We show by acridine orange, that the reduced chloride transport leads to reduced acidification. We show that the residual activity is sensitive to inhibitors of cathepsins and chloride channels, confirming that resorption is reduced but present. In conclusion, this is the first functional in vitro study of human ADOII osteoclasts. We show normal osteoclastogenesis in ADOII osteoclasts. However, the residual activity of the ClC-7 channel in ADOII osteoclasts does not allow sufficient acidification and thereby resorption.
KW - Acid Phosphatase
KW - Acridine Orange
KW - Age Factors
KW - Antigens, CD14
KW - Biological Transport
KW - Bone Resorption
KW - Calcium Phosphates
KW - Cathepsin K
KW - Cathepsins
KW - Cell Differentiation
KW - Cell Fusion
KW - Chloride Channels
KW - Chlorides
KW - Enzyme Inhibitors
KW - Humans
KW - Immunoblotting
KW - Immunohistochemistry
KW - Isoenzymes
KW - Macrolides
KW - Monocytes
KW - Mutation
KW - Osteoclasts
KW - Osteopetrosis
KW - Sex Factors
KW - Time Factors
U2 - 10.1016/S0002-9440(10)63712-1
DO - 10.1016/S0002-9440(10)63712-1
M3 - Journal article
C2 - 15111300
VL - 164
SP - 1537
EP - 1545
JO - American Journal of Pathology
JF - American Journal of Pathology
SN - 0002-9440
IS - 5
ER -
ID: 47557111