Inhibitory Effects of a Tryptamine Derivative on Ultraviolet Radiation-Induced Apoptosis in MC3T3-E1 Mouse Osteoblasts

• Published in: Journal of pharmacological sciences Vol. 115; no. 2; p. 214
• Main Authors: Mikami, Yoshikazu, Senoo, Motoki, Lee, Mio, Yamada, Kiyoshi, Ochiai, Kuniyasu, Honda, Masaki J, Watanabe, Eri, Watanabe, Nobukazu, Somei, Masanori, Takagi, Minoru
• Format: Journal Article
• Language: English
• Published: Japan 01.02.2011
• Subjects: MS-IPA1; tryptamine; apoptosis
• ISSN: 1347-8648
• DOI: 10.1254/jphs.10208FP

MS-IPA1 is a new synthetic compound that is synthesized from tryptamine. Recently, our group demonstrated that SST-VED-I-1, which has a similar chemical structure to MS-IPA1, inhibits starvation-induced apoptosis in osteoblasts. However, the effects of MS-IPA1 on apoptosis in osteoblasts have not yet been examined. Therefore, this study examined the effects of this compound on apoptosis in osteoblasts. In this study, MC3T3-E1 mouse osteoblasts were used and apoptosis was induced by ultraviolet radiation (UV). We investigated the effect of MS-IPA1 on apoptosis by analyzing caspase3/7 activity, translocation of phosphatidylserine (PS), and mRNA expression levels of Bcl-2 and Bax. In addition, it was investigated whether MS-IPA1 affects cell proliferation and cell cycle progression. We found that MS-IPA1 had no effect on cell proliferation or cell cycle progression. However, MS-IPA1 suppressed UV-induced cell death in a dose-dependent manner, which was accompanied with the inhibition of caspase activation and translocation of PS. Furthermore, after UV exposure, Bcl-2 expression was increased in the MS-IPA1-treated cells as compared to that in the vehicle-treated cells. In contrast, Bax expression was decreased in the MS-IPA1-treated cell as compared to that in the vehicle-treated cells. These results suggest that MS-IPA1 has an inhibitory effect on apoptosis in osteoblasts through a Bcl-2 family-dependent signaling pathway.