Caffeine decreases vitamin D receptor protein expression and 1,25(OH)2D3 stimulated alkaline phosphatase activity in human osteoblast cells

Prema B. Rapuri, John Christopher G. Gallagher, Zafar Nawaz

Research output: Contribution to journalArticle

45 Citations (Scopus)

Abstract

Of the various risk factors contributing to osteoporosis, dietary/lifestyle factors are important. In a clinical study we reported that women with caffeine intakes >300 mg/day had higher bone loss and women with vitamin D receptor (VDR) variant, tt were at a greater risk for this deleterious effect of caffeine. However, the mechanism of how caffeine effects bone metabolism is not clear. 1,25-Dihydroxy vitamin D3 (1,25(OH)2D3) plays a critical role in regulating bone metabolism. The receptor for 1,25(OH)2D3, VDR has been demonstrated in osteoblast cells and it belongs to the superfamily of nuclear hormone receptors. To understand the molecular mechanism of the role of caffeine in relation to bone, we tested the effect of caffeine on VDR expression and 1,25(OH)2D3 mediated actions in bone. We therefore examined the effect of different doses of caffeine (0.2, 0.5, 1.0 and 10 mM) on 1,25(OH)2D3 induced VDR protein expression in human osteoblast cells. We also tested the effect of different doses of caffeine on 1,25(OH)2D3 induced alkaline phosphatase (ALP) activity, a widely used marker of osteoblastic activity. Caffeine dose dependently decreased the 1,25(OH)2D3 induced VDR expression and at concentrations of 1 and 10 mM, VDR expression was decreased by about 50-70%, respectively. In addition, the 1,25(OH)2D3 induced alkaline phosphatase activity was also reduced at similar doses thus affecting the osteoblastic function. The basal ALP activity was not affected with increasing doses of caffeine. Overall, our results suggest that caffeine affects 1,25(OH)2D3 stimulated VDR protein expression and 1,25(OH)2D3 mediated actions in human osteoblast cells.

Original languageEnglish
Pages (from-to)368-371
Number of pages4
JournalJournal of Steroid Biochemistry and Molecular Biology
Volume103
Issue number3-5
DOIs
StatePublished - Mar 2007

Fingerprint

Calcitriol Receptors
Osteoblasts
Caffeine
Human Activities
Alkaline Phosphatase
Bone
Proteins
Bone and Bones
Metabolism
Cytoplasmic and Nuclear Receptors
Osteoporosis
Life Style

All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Endocrinology

Cite this

@article{bc3929ca44a8481799c9df48746f60ac,
title = "Caffeine decreases vitamin D receptor protein expression and 1,25(OH)2D3 stimulated alkaline phosphatase activity in human osteoblast cells",
abstract = "Of the various risk factors contributing to osteoporosis, dietary/lifestyle factors are important. In a clinical study we reported that women with caffeine intakes >300 mg/day had higher bone loss and women with vitamin D receptor (VDR) variant, tt were at a greater risk for this deleterious effect of caffeine. However, the mechanism of how caffeine effects bone metabolism is not clear. 1,25-Dihydroxy vitamin D3 (1,25(OH)2D3) plays a critical role in regulating bone metabolism. The receptor for 1,25(OH)2D3, VDR has been demonstrated in osteoblast cells and it belongs to the superfamily of nuclear hormone receptors. To understand the molecular mechanism of the role of caffeine in relation to bone, we tested the effect of caffeine on VDR expression and 1,25(OH)2D3 mediated actions in bone. We therefore examined the effect of different doses of caffeine (0.2, 0.5, 1.0 and 10 mM) on 1,25(OH)2D3 induced VDR protein expression in human osteoblast cells. We also tested the effect of different doses of caffeine on 1,25(OH)2D3 induced alkaline phosphatase (ALP) activity, a widely used marker of osteoblastic activity. Caffeine dose dependently decreased the 1,25(OH)2D3 induced VDR expression and at concentrations of 1 and 10 mM, VDR expression was decreased by about 50-70{\%}, respectively. In addition, the 1,25(OH)2D3 induced alkaline phosphatase activity was also reduced at similar doses thus affecting the osteoblastic function. The basal ALP activity was not affected with increasing doses of caffeine. Overall, our results suggest that caffeine affects 1,25(OH)2D3 stimulated VDR protein expression and 1,25(OH)2D3 mediated actions in human osteoblast cells.",
author = "Rapuri, {Prema B.} and Gallagher, {John Christopher G.} and Zafar Nawaz",
year = "2007",
month = "3",
doi = "10.1016/j.jsbmb.2006.12.037",
language = "English",
volume = "103",
pages = "368--371",
journal = "Journal of Steroid Biochemistry and Molecular Biology",
issn = "0960-0760",
publisher = "Elsevier Limited",
number = "3-5",

}

TY - JOUR

T1 - Caffeine decreases vitamin D receptor protein expression and 1,25(OH)2D3 stimulated alkaline phosphatase activity in human osteoblast cells

AU - Rapuri, Prema B.

AU - Gallagher, John Christopher G.

AU - Nawaz, Zafar

PY - 2007/3

Y1 - 2007/3

N2 - Of the various risk factors contributing to osteoporosis, dietary/lifestyle factors are important. In a clinical study we reported that women with caffeine intakes >300 mg/day had higher bone loss and women with vitamin D receptor (VDR) variant, tt were at a greater risk for this deleterious effect of caffeine. However, the mechanism of how caffeine effects bone metabolism is not clear. 1,25-Dihydroxy vitamin D3 (1,25(OH)2D3) plays a critical role in regulating bone metabolism. The receptor for 1,25(OH)2D3, VDR has been demonstrated in osteoblast cells and it belongs to the superfamily of nuclear hormone receptors. To understand the molecular mechanism of the role of caffeine in relation to bone, we tested the effect of caffeine on VDR expression and 1,25(OH)2D3 mediated actions in bone. We therefore examined the effect of different doses of caffeine (0.2, 0.5, 1.0 and 10 mM) on 1,25(OH)2D3 induced VDR protein expression in human osteoblast cells. We also tested the effect of different doses of caffeine on 1,25(OH)2D3 induced alkaline phosphatase (ALP) activity, a widely used marker of osteoblastic activity. Caffeine dose dependently decreased the 1,25(OH)2D3 induced VDR expression and at concentrations of 1 and 10 mM, VDR expression was decreased by about 50-70%, respectively. In addition, the 1,25(OH)2D3 induced alkaline phosphatase activity was also reduced at similar doses thus affecting the osteoblastic function. The basal ALP activity was not affected with increasing doses of caffeine. Overall, our results suggest that caffeine affects 1,25(OH)2D3 stimulated VDR protein expression and 1,25(OH)2D3 mediated actions in human osteoblast cells.

AB - Of the various risk factors contributing to osteoporosis, dietary/lifestyle factors are important. In a clinical study we reported that women with caffeine intakes >300 mg/day had higher bone loss and women with vitamin D receptor (VDR) variant, tt were at a greater risk for this deleterious effect of caffeine. However, the mechanism of how caffeine effects bone metabolism is not clear. 1,25-Dihydroxy vitamin D3 (1,25(OH)2D3) plays a critical role in regulating bone metabolism. The receptor for 1,25(OH)2D3, VDR has been demonstrated in osteoblast cells and it belongs to the superfamily of nuclear hormone receptors. To understand the molecular mechanism of the role of caffeine in relation to bone, we tested the effect of caffeine on VDR expression and 1,25(OH)2D3 mediated actions in bone. We therefore examined the effect of different doses of caffeine (0.2, 0.5, 1.0 and 10 mM) on 1,25(OH)2D3 induced VDR protein expression in human osteoblast cells. We also tested the effect of different doses of caffeine on 1,25(OH)2D3 induced alkaline phosphatase (ALP) activity, a widely used marker of osteoblastic activity. Caffeine dose dependently decreased the 1,25(OH)2D3 induced VDR expression and at concentrations of 1 and 10 mM, VDR expression was decreased by about 50-70%, respectively. In addition, the 1,25(OH)2D3 induced alkaline phosphatase activity was also reduced at similar doses thus affecting the osteoblastic function. The basal ALP activity was not affected with increasing doses of caffeine. Overall, our results suggest that caffeine affects 1,25(OH)2D3 stimulated VDR protein expression and 1,25(OH)2D3 mediated actions in human osteoblast cells.

UR - http://www.scopus.com/inward/record.url?scp=33947117413&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33947117413&partnerID=8YFLogxK

U2 - 10.1016/j.jsbmb.2006.12.037

DO - 10.1016/j.jsbmb.2006.12.037

M3 - Article

VL - 103

SP - 368

EP - 371

JO - Journal of Steroid Biochemistry and Molecular Biology

JF - Journal of Steroid Biochemistry and Molecular Biology

SN - 0960-0760

IS - 3-5

ER -