Dexamethasone induces sodium-dependant vitamin C transporter in a mouse osteoblastic cell line MC3T3-E1

Br J Nutr. 2001 Aug;86(2):145-9. doi: 10.1079/bjn2001406.

Abstract

The regulation of intracellular ascorbic acid (AsA) levels may be under the control of an AsA-specific membrane transporter. The present study investigates AsA uptake and expression of Na-dependent vitamin C transporter (SVCT) mRNA in the mouse osteoblastic cell line, MC3T3-E1. Among eight compounds tested, dexamethasone (Dex) all-trans retinoic acid, transforming growth factor beta, prostaglandin E2 and transferrin significantly and respectively) stimulated the update of AsA into MC3T3-E1 cells. Among these five, Dex was the most active, inducing mSVCT2 mRNA and the uptake of AsA in a time- and concentration-dependant manner. Dex did not induce mSVCT1 mRNA. These results suggest that the Dex-induced stimulation of AsA incorporation into osteoblastic cells is mediated by the induction of mSVCT2. Since Dex reduced alkaline phosphatase activity in MC3T3-E1 cells in our culture conditions, Dex-induced stimulation of AsA incorporation might not be the result of differentiation. Hormone-regulated changes of SVCT expression may have an important role in cell functions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaline Phosphatase / metabolism
  • Animals
  • Ascorbic Acid / metabolism*
  • Carrier Proteins / genetics*
  • Dexamethasone / pharmacology*
  • Dose-Response Relationship, Drug
  • Glucocorticoids / pharmacology*
  • Mice
  • Organic Anion Transporters, Sodium-Dependent*
  • Osteoblasts / drug effects*
  • Osteoblasts / metabolism
  • RNA, Messenger / analysis*
  • Sodium-Coupled Vitamin C Transporters
  • Stimulation, Chemical
  • Symporters*
  • Tumor Cells, Cultured / drug effects

Substances

  • Carrier Proteins
  • Glucocorticoids
  • Organic Anion Transporters, Sodium-Dependent
  • RNA, Messenger
  • Sodium-Coupled Vitamin C Transporters
  • Symporters
  • Dexamethasone
  • Alkaline Phosphatase
  • Ascorbic Acid