1,25-Dihydroxyvitamin D3 induces the expression of vascular endothelial growth factor in osteoblastic cells

Endocr Res. 1997 Aug;23(3):213-29. doi: 10.3109/07435809709031855.

Abstract

Angiogenesis is a fundamental process in skeletal development and repair, and previous studies indicate that vascular endothelial growth factor (VEGF), an endothelial cell-specific angiogenic factor, may be involved in bone formation and repair. Therefore, we studied the hormonal regulation of VEGF expression in SaOS-2 osteoblast-like cells, both at the protein level, and at the transcriptional level by transient transfection experiments. 1,25-Dihydroxyvitamin D3 [1,25-(OH)2D3], increased VEGF expression by approximately 3-fold, and the increase was dose dependent, with maximum stimulation between 1.0 and 10 nM of 1,25-(OH)2D3. Up-regulation of VEGF protein was detected already after 6 h of treatment. VEGF up-regulation was also observed in ROS-17/2.8 and OHS-4 osteoblast-like cells but not in MCF-7 and MDA-MB231 breast carcinoma cells. Dexamethasone (Dex) decreased VEGF expression to 40% of the control, but when added together with 1,25-(OH)2D3, had no effects on the up-regulation of VEGF by 1,25-(OH)2D3. PTH1-34 stimulated weakly VEGF expression, but combined with 1,25-(OH)2D3, resulted in a close to 5-fold stimulation. A 4-day pretreatment of the cells with Dex increased the vitamin D3 receptor expression and resulted in a stronger stimulation of VEGF by 1,25-(OH)2D3, alone or in combination with PTH1-34. The results show that the VEGF promoter is a target of 1,25-(OH)2D3 regulation in osteoblasts, despite the lack of classical vitamin D3 responsive elements. The up-regulation of VEGF in osteoblast-like cells by calciotropic hormones provides additional evidence of the involvement of VEGF in bone metabolism.

MeSH terms

  • Breast Neoplasms
  • Calcitriol / pharmacology*
  • Cell Line
  • Dexamethasone / pharmacology
  • Endothelial Growth Factors / genetics*
  • Gene Expression / drug effects*
  • Glucocorticoids / pharmacology
  • Humans
  • Lymphokines / genetics*
  • Osteoblasts / metabolism*
  • Recombinant Proteins
  • Teriparatide / pharmacology
  • Transfection
  • Tumor Cells, Cultured
  • Vascular Endothelial Growth Factor A
  • Vascular Endothelial Growth Factors

Substances

  • Endothelial Growth Factors
  • Glucocorticoids
  • Lymphokines
  • Recombinant Proteins
  • Vascular Endothelial Growth Factor A
  • Vascular Endothelial Growth Factors
  • Teriparatide
  • Dexamethasone
  • Calcitriol