TY - JOUR
T1 - High osteoblastic activity in C3H/HeJ mice compared to C57BL/6J mice is associated with low apoptosis in C3H/HeJ osteoblasts
AU - Sheng, M. H.C.
AU - Lau, K. H.W.
AU - Mohan, S.
AU - Baylink, D. J.
AU - Wergedal, J. E.
N1 - M. H.-C. Sheng K.-H. W. Lau S. Mohan D. J. Baylink J. E. Wergedal This study sought to confirm that osteoblasts of C3H/HeJ (C3H) mice, which have higher differentiation status and bone-forming ability compared to C57BL/6J (B6) osteoblasts, also have a lower apoptosis level and to test whether the higher differentiation status and bone-forming ability of C3H osteoblasts were related to the lower apoptosis.
PY - 2006/5
Y1 - 2006/5
N2 - This study sought to confirm that osteoblasts of C3H/HeJ (C3H) mice, which have higher differentiation status and bone-forming ability compared to C57BL/6J (B6) osteoblasts, also have a lower apoptosis level and to test whether the higher differentiation status and bone-forming ability of C3H osteoblasts were related to the lower apoptosis. C3H mice had 50% fewer (P < 0.01) apoptotic osteoblasts on the endocortical bone surface than B6 mice as determined by the TUNEL assay. Primary C3H osteoblasts in cultures also showed a 50% (P < 0.05) lower apoptosis level than B6 osteoblasts assayed by acridine orange/ethidium bromide staining of apoptotic osteoblasts. The lower apoptosis in C3H osteoblasts was accompanied by 22% (P < 0.05) and 56% (P < 0.001) reduction in the activity of total caspases and caspases 3/7, respectively. C3H osteoblasts also displayed greater alkaline phosphatase (ALP) activity (P < 0.001) and higher expression of Cbfa1, type-1 collagen, osteopontin, and osteocalcin genes (P < 0.05 for each). To assess if an association existed between population apoptosis and the differentiation status (ALP-specific activity) and/or bone-forming activity (insoluble collagen synthesis), C3H and B6 osteoblasts were treated with several apoptosis enhancers (tumor necrosis factor-α, dexamethasone, lipopolysaccharide, etoposide) and inhibitors (parathyroid hormone, insulin-like growth factor I, transforming growth factor β1, estradiol). Both ALP (r = -0.61, P < 0.001) and insoluble collagen synthesis (r = -0.61, P < 0.001) were inversely correlated with apoptosis, suggesting that differentiation (maturation) and/or bone-forming activity of these mouse osteoblasts were inversely associated with apoptosis. In conclusion, these studies support the premise that higher bone density and bone formation rate in C3H mice could be due in part to lower apoptosis in C3H osteoblasts. © 2006 Springer Science+Business Media, Inc.
AB - This study sought to confirm that osteoblasts of C3H/HeJ (C3H) mice, which have higher differentiation status and bone-forming ability compared to C57BL/6J (B6) osteoblasts, also have a lower apoptosis level and to test whether the higher differentiation status and bone-forming ability of C3H osteoblasts were related to the lower apoptosis. C3H mice had 50% fewer (P < 0.01) apoptotic osteoblasts on the endocortical bone surface than B6 mice as determined by the TUNEL assay. Primary C3H osteoblasts in cultures also showed a 50% (P < 0.05) lower apoptosis level than B6 osteoblasts assayed by acridine orange/ethidium bromide staining of apoptotic osteoblasts. The lower apoptosis in C3H osteoblasts was accompanied by 22% (P < 0.05) and 56% (P < 0.001) reduction in the activity of total caspases and caspases 3/7, respectively. C3H osteoblasts also displayed greater alkaline phosphatase (ALP) activity (P < 0.001) and higher expression of Cbfa1, type-1 collagen, osteopontin, and osteocalcin genes (P < 0.05 for each). To assess if an association existed between population apoptosis and the differentiation status (ALP-specific activity) and/or bone-forming activity (insoluble collagen synthesis), C3H and B6 osteoblasts were treated with several apoptosis enhancers (tumor necrosis factor-α, dexamethasone, lipopolysaccharide, etoposide) and inhibitors (parathyroid hormone, insulin-like growth factor I, transforming growth factor β1, estradiol). Both ALP (r = -0.61, P < 0.001) and insoluble collagen synthesis (r = -0.61, P < 0.001) were inversely correlated with apoptosis, suggesting that differentiation (maturation) and/or bone-forming activity of these mouse osteoblasts were inversely associated with apoptosis. In conclusion, these studies support the premise that higher bone density and bone formation rate in C3H mice could be due in part to lower apoptosis in C3H osteoblasts. © 2006 Springer Science+Business Media, Inc.
KW - Apoptosis
KW - Differentiation
KW - Genetic regulation
KW - Mice
KW - Osteoblast
KW - Bone Resorption/genetics
KW - Cell Differentiation/drug effects
KW - Growth Substances/pharmacology
KW - Species Specificity
KW - Mice, Inbred C57BL
KW - Tumor Necrosis Factor-alpha/pharmacology
KW - Apoptosis/drug effects
KW - Cells, Cultured
KW - Mice, Inbred C3H
KW - Caspases/metabolism
KW - Osteogenesis/drug effects
KW - Osteoblasts/cytology
KW - Animals
KW - Collagen/biosynthesis
KW - Bone Density/drug effects
KW - Bone and Bones/cytology
KW - Down-Regulation/genetics
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UR - https://www.mendeley.com/catalogue/a12868c3-5c63-3116-97b1-91481d33562f/
U2 - 10.1007/s00223-005-0303-5
DO - 10.1007/s00223-005-0303-5
M3 - Article
C2 - 16604280
SN - 0171-967X
VL - 78
SP - 293
EP - 301
JO - Calcified Tissue International
JF - Calcified Tissue International
IS - 5
ER -