Age- and sex-dependent hormonal modulation of the expression of vitamin D receptor and 25-hydroxyvitamin D 1α hydroxylase in human bone cells

Abstract

Background: Human cultured osteoblasts from pre-Ob, post-Ob or m-Ob express different mRNAs and respond to different hormones. Aims: To test expression and hormonal modulation of VDR and 1OHase and 1,25D production in hObs. Methods: hObs obtained from bone explants were prepared, treated and analyzed as before. Results: (i) VDR and 1OHase were expressed in all hObs. (ii) 1,25D was produced similarly. (iii) Treatment with E₂, DPN (ER agonist), but not PPT (ER agonist) increased VDR. (iv) These hormones increased 1OHase. (v) Vitamin D analog JKF and PTH 1-84 increased similarly mRNAs. (vi) Treatment with E₂, DPN and PPT increased 1,25D. (vii) JKF and PTH increased similarly 1,25D. (viii) DNA synthesis and CK were stimulated by all hormones in hObs. Conclusions: Hormonal modulation of VDR and 1OHase and 1,25D production is important for bone physiology but their correlation, activity and bone physiology is not yet clear.

Keywords::

• 1,25D
• 1OHase
• estrogens
• JKF
• osteoblasts
• PTH
• VDR

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• Human-derived cultured osteoblast from pre-, post-menopausal women or men expressed vitamin D receptor and 1α hydroxylase and produce 1,25(OH)₂D₃.

• These mRNAs expression and activity were modulated by estrogens in the different osteoblasts.

• These mRNAs expression and activity were modulated by parathyroid 1-84 hormone and JK 1624F₂-2 in the different osteoblasts.

• These hormonal modulations are an addition to the known aspects of bone physiology.

Notes