J Korean Acad Periodontol.  2000 Mar;30(1):39-50.

The Effects of 1,25-Dihydroxyvitamin D3 on Expression of IGF-I Gene and Cellular Proliferation in MC3T3-E1 Cells

• Choi HD
• Lee JM
• Suh JY

Abstract

Polypeptide growth factor belong to a class of potent biologic mediator which regulate cell differentiation, proliferation, migration and metabolism. 1,25-dihydroxyvitamin D3 decrease cell proliferation, and stimulate alkaline phosphatase activity which express in osteoblast during cell differentiation period. IGF-I is known to stimulate cell proliferation and differentiation too. 1,25-dihydroxyvitamin D3 is known to increase IGF-I binding sites and IGF binding protein which inhibite the effect of IGF. The purpose of this study is to evaluate potential role of IGF-I as mediator that control the action of 1,25-dihydroxyvitamin D3. MC3T3-E1 cell were seeded 5x10(5)/ml at 100mm culture plate in alpha-MEM containing 10% fetal bovine serum. After 48 hour incubation period, medium were changed alpha-MEM containing 5% fetal bovine serum. After 24 hours, 10(-9)M 1,25-dihydroxyvitamin D3 added. Total mRNA was extracted at 0, 6, 24, 48, 72 hour. PR-PCR method was programed for the detection of IGF-I mRNA. In the both groups of 1,25-dihydroxy vitamin D3 treated and control, alternative splicing form of IGF-I, IGF-IA and IGF-IB were expressed. In the 1,25-dihydroxyvitamin D3 treated group, IGF-I mRNA expression was matained until 24 hour, there after expression was decresed. MC3T3-E1 cell were seeded 2.5x10(4)/ml at 24well plate in alpha-MEM containing 10% fetal bovine serum. After 48 hour incubation period, medium were changed alpha-MEM containing 3% fetal bovine serum. After 24 hours, 10(-9)M 1,25-dihydroxyvitamin D3 and 10 ng/ml IGF-I were added separately or together. Cell were cultured for 1 and 3 days, 2micronCi/ml [3H]-thymidine was added for the last 24h of culture of each days. [3H]-thymidine incorporation in to DNA was measured and expressed counter per minute(CPM). DNA synthetic activity was significantly decreased by 1,25-dihydroxyvitamin D3 both at 1 day and 3 day, and in the combination group of 1,25-dihydroxyvitamin D3 and IGF-I, DNA synthetic activity was also decreased both at 1 day and 3 days. IGF-I did not affect the DNA synthetic activity compared to control group both at 1 day and 3 day. From the above results, 1,25-dihydroxyvitamin D3 was potent inhibitor of cell proliferaton in MC3T3-E1 cells. It assumed that the effect of 1,25-dihydroxyvitamin D3 on osteoblast proliferation may be mediated in part by decreased level of IGF-I.

MeSH Terms

Alkaline Phosphatase
Alternative Splicing
Binding Sites
Calcitriol*
Carrier Proteins
Cell Differentiation
Cell Proliferation*
Cholecalciferol
DNA
Insulin-Like Growth Factor I*
Metabolism
Osteoblasts
RNA, Messenger
Alkaline Phosphatase
Calcitriol
Carrier Proteins
Cholecalciferol
DNA
Insulin-Like Growth Factor I
RNA, Messenger