ERK MAP kinase is required in 1,25(OH) sub(2)D sub(3)-induced differentiation in human osteoblasts

• Published in: Immunopharmacology and immunotoxicology Vol. 24; no. 1; pp. 31 - 41
• Main Authors: Chae, HJ, Jeong, B J, Ha, MS, Lee, J K, Byun, JO, Jung, W Y, Yun, Y G, Lee, D G, Oh, SH, Chae, S W, Kwak, Y G, Kim, H H, Lee, Z H, Kim, H R
• Format: Journal Article
• Language: English
• Published: 01.02.2002
• Subjects: extracellular signal-regulated kinase
• ISSN: 0892-3973

Expression of alkaline phosphatase (ALP) activity represents a key event during the differentiation processes of osteoblasts, and the level of ALP activity has been routinely used as a relative measure of differentiation stages of osteoblasts. In human osteoblasts, we showed that vitamin D sub(3) analogue, 1,25(OH) sub(2)D sub(3), had a stimulatory effect on ALP activity after 3 days, compared with control. The treatment of PD098059, an ERK MAP Kinase inhibitor, had a reducing effect on ALP activity, a differentiation marker in 1,25(OH) sub(2)D sub(3)-treated primary human osteoblasts. However, SB203580, a potent p38 MAP Kinase inhibitor, had no effect on the differentiation in this system. This indicates that ERK, not p38, is directly related to 1,25(OH) sub(2)D sub(3)-stimulated ALP activity in primary human osteoblasts. These results also show that the vitamin D sub(3) analogue stimulates ERK1 activation in primary human osteoblasts. This finding provides one of signaling pathways for differentiation in primary human osteoblasts.