Abstract
Conditioned medium from cultured normal human foreskin keratinocytes enhanced the release of calcium from neonatal mouse calvaria in organ culture. Unfractionated keratinocyte-conditioned medium (KCM) stimulated bone resorption in a dose-dependent manner, but it did not increase the concentration of prostaglandin E2 (PGE2) in the bone culture medium until a maximal dose of KCM for resorption was used. Furthermore, inhibitors of PGE2 synthesis, indomethacin, ibuprofen, and piroxicam, did not inhibit KCM-induced calcium release. High concentrations of KCM increased cAMP production by calvaria in the presence of isobutylmethylxanthine, but the increase was small compared with that produced by a dose of bovine PTH that caused a similar level of bone resorption. The bone resorption-stimulating activity of KCM was not lost after incubation at 56 C for 60 min, but it was lost after heating at 100 C for 10 min. Fractionation of KCM by gel filtration chromatography revealed two distinct peaks of bone resorption-stimulating activity. One peak, KCM(I), caused a significant increase in bone resorption at 2 μg protein/ml. KCM(I) did not increase medium PGE2, and inhibition of PGE2 synthesis in bone had no effect on KCM(I)-induced bone resorption. KCM(I) failed to increase cAMP production by human osteosarcoma SaOS-2 cells. Another peak, KCM(II), caused a dose-dependent increase in bone resorption, and a significant increase in medium calcium was noted at a 20-fold lower concentration (0.1 μg protein/ml) than with KCM(I). In contrast to KCM(I), the increase in bone resorption stimulated by KCM(II) was accompanied by a parallel increase in the production of PGE2, and inhibition of PGE2 synthesis completely inhibited the bone resorption-stimulating activity of KCM(II). KCM(II) also caused an increase in cAMP production by SaOS-2 cells. We conclude that KCM contains at least two distinct bone resorption-stimulating factors, one of which acts via a PG-mediated mechanism and the other by a PG-independent pathway.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 2467-2475 |
| Number of pages | 9 |
| Journal | Endocrinology |
| Volume | 122 |
| Issue number | 6 |
| State | Published - 1988 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Endocrinology
- Endocrinology, Diabetes and Metabolism
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Evidence for multiple bone resorption-stimulating factors produced by normal human keratinocytes in culture. / Fried, R. M.; Voelkel, E. F.; Rice, R. H.; Levine, L.; Tashjian, A. H.
In: Endocrinology, Vol. 122, No. 6, 1988, p. 2467-2475.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Evidence for multiple bone resorption-stimulating factors produced by normal human keratinocytes in culture
AU - Fried, R. M.
AU - Voelkel, E. F.
AU - Rice, R. H.
AU - Levine, L.
AU - Tashjian, A. H.
PY - 1988
Y1 - 1988
N2 - Conditioned medium from cultured normal human foreskin keratinocytes enhanced the release of calcium from neonatal mouse calvaria in organ culture. Unfractionated keratinocyte-conditioned medium (KCM) stimulated bone resorption in a dose-dependent manner, but it did not increase the concentration of prostaglandin E2 (PGE2) in the bone culture medium until a maximal dose of KCM for resorption was used. Furthermore, inhibitors of PGE2 synthesis, indomethacin, ibuprofen, and piroxicam, did not inhibit KCM-induced calcium release. High concentrations of KCM increased cAMP production by calvaria in the presence of isobutylmethylxanthine, but the increase was small compared with that produced by a dose of bovine PTH that caused a similar level of bone resorption. The bone resorption-stimulating activity of KCM was not lost after incubation at 56 C for 60 min, but it was lost after heating at 100 C for 10 min. Fractionation of KCM by gel filtration chromatography revealed two distinct peaks of bone resorption-stimulating activity. One peak, KCM(I), caused a significant increase in bone resorption at 2 μg protein/ml. KCM(I) did not increase medium PGE2, and inhibition of PGE2 synthesis in bone had no effect on KCM(I)-induced bone resorption. KCM(I) failed to increase cAMP production by human osteosarcoma SaOS-2 cells. Another peak, KCM(II), caused a dose-dependent increase in bone resorption, and a significant increase in medium calcium was noted at a 20-fold lower concentration (0.1 μg protein/ml) than with KCM(I). In contrast to KCM(I), the increase in bone resorption stimulated by KCM(II) was accompanied by a parallel increase in the production of PGE2, and inhibition of PGE2 synthesis completely inhibited the bone resorption-stimulating activity of KCM(II). KCM(II) also caused an increase in cAMP production by SaOS-2 cells. We conclude that KCM contains at least two distinct bone resorption-stimulating factors, one of which acts via a PG-mediated mechanism and the other by a PG-independent pathway.
AB - Conditioned medium from cultured normal human foreskin keratinocytes enhanced the release of calcium from neonatal mouse calvaria in organ culture. Unfractionated keratinocyte-conditioned medium (KCM) stimulated bone resorption in a dose-dependent manner, but it did not increase the concentration of prostaglandin E2 (PGE2) in the bone culture medium until a maximal dose of KCM for resorption was used. Furthermore, inhibitors of PGE2 synthesis, indomethacin, ibuprofen, and piroxicam, did not inhibit KCM-induced calcium release. High concentrations of KCM increased cAMP production by calvaria in the presence of isobutylmethylxanthine, but the increase was small compared with that produced by a dose of bovine PTH that caused a similar level of bone resorption. The bone resorption-stimulating activity of KCM was not lost after incubation at 56 C for 60 min, but it was lost after heating at 100 C for 10 min. Fractionation of KCM by gel filtration chromatography revealed two distinct peaks of bone resorption-stimulating activity. One peak, KCM(I), caused a significant increase in bone resorption at 2 μg protein/ml. KCM(I) did not increase medium PGE2, and inhibition of PGE2 synthesis in bone had no effect on KCM(I)-induced bone resorption. KCM(I) failed to increase cAMP production by human osteosarcoma SaOS-2 cells. Another peak, KCM(II), caused a dose-dependent increase in bone resorption, and a significant increase in medium calcium was noted at a 20-fold lower concentration (0.1 μg protein/ml) than with KCM(I). In contrast to KCM(I), the increase in bone resorption stimulated by KCM(II) was accompanied by a parallel increase in the production of PGE2, and inhibition of PGE2 synthesis completely inhibited the bone resorption-stimulating activity of KCM(II). KCM(II) also caused an increase in cAMP production by SaOS-2 cells. We conclude that KCM contains at least two distinct bone resorption-stimulating factors, one of which acts via a PG-mediated mechanism and the other by a PG-independent pathway.
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M3 - Article
VL - 122
SP - 2467
EP - 2475
JO - Endocrinology
JF - Endocrinology
SN - 0013-7227
IS - 6
ER -