In vitro vitamin K(2) and 1α,25-dihydroxyvitamin D(3) combination enhances osteoblasts anabolism of diabetic mice

Eur J Pharmacol. 2015 Nov 15:767:30-40. doi: 10.1016/j.ejphar.2015.09.048. Epub 2015 Oct 8.

Abstract

In this study, we evaluated the anabolic effect and the underlying cellular mechanisms involved of vitamin K2 (10 nM) and 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) (10 nM), alone and in combination, on primary osteoblasts harvested from the iliac crests of C57BL/KsJ lean (+/+) and obese/diabetic (db/db) mice. A lower alkaline phosphatase (ALP) activity plus a reduced expression of bone anabolic markers and bone formation transcription factors (osteocalcin, Runx2, Dlx5, ATF4 and OSX) were consistently detected in osteoblasts of db/db mice compared to lean mice. A significantly higher calcium deposits formation in osteoblasts was observed in lean mice when compared to db/db mice. Co-administration of vitamin K2 (10 nM) and 1,25(OH)2D3 (10 nM) caused an enhancement of calcium deposits in osteoblasts in both strains of mice. Vitamins K2 and 1,25(OH)2D3 co-administration time-dependently (7, 14 and 21 days) increased the levels of bone anabolic markers and bone formation transcription factors, with a greater magnitude of increase observed in osteoblasts of db/db mice. Combined vitamins K2 plus 1,25(OH)2D3 treatment significantly enhanced migration and the re-appearance of surface microvilli and ruffles of osteoblasts of db/db mice. Thus, our results illustrate that vitamins K2 plus D3 combination could be a novel therapeutic strategy in treating diabetes-associated osteoporosis.

Keywords: 1,25(OH)(2)D(3); Osteoblasts; Osteoporosis; Type 2 diabetes mellitus; Vitamin K(2).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Activating Transcription Factor 4
  • Alkaline Phosphatase / metabolism
  • Animals
  • Calcitriol
  • Calcium / metabolism
  • Cells, Cultured
  • Core Binding Factor Alpha 1 Subunit / biosynthesis
  • Diabetes Mellitus, Experimental / metabolism*
  • Drug Synergism
  • Homeodomain Proteins
  • Male
  • Mice
  • Osteoblasts / drug effects*
  • Osteoblasts / metabolism*
  • Osteocalcin / biosynthesis
  • Osteogenesis / drug effects*
  • Sp7 Transcription Factor
  • Transcription Factors / biosynthesis
  • Vitamin D / analogs & derivatives*
  • Vitamin D / pharmacology
  • Vitamin K 2 / pharmacology*

Substances

  • Atf4 protein, mouse
  • Core Binding Factor Alpha 1 Subunit
  • Dlx5 protein, mouse
  • Homeodomain Proteins
  • Runx2 protein, mouse
  • Sp7 Transcription Factor
  • Sp7 protein, mouse
  • Transcription Factors
  • dihydroxy-vitamin D3
  • Osteocalcin
  • Vitamin K 2
  • Vitamin D
  • Activating Transcription Factor 4
  • Alkaline Phosphatase
  • Calcitriol
  • Calcium