東京医科歯科大学 歯学部
東京医科歯科大学 歯学部
大阪大学 医学部
東レリサーチセンター 生物科学研究部
東レリサーチセンター 生物科学研究部
北海道大学 歯学部
北海道大学 歯学部
宇宙開発事業団 筑波宇宙センター
宇宙開発事業団 筑波宇宙センター
NASA Johnson Space Center
著者所属（英）
Tokyo Medical and Dental University Faculty of Dentistry
Tokyo Medical and Dental University Faculty of Dentistry
Osaka University Medical School
Toray Research Center Inc Department of Biological Science
Toray Research Center Inc Department of Biological Science
Hokkaido University School of Dentistry
Hokkaido University School of Dentistry
National Space Development Agency of Japan Tsukuba Space Center
National Space Development Agency of Japan Tsukuba Space Center
NASA Johnson Space Center
出版者
宇宙開発事業団
出版者（英）
National Space Development Agency of Japan (NASDA)
The increase of urinary calcium and decrease of bone density, bone demineralization have been reported in astronauts. Inhibition of bone formation was reported in rats that were flown for two to three weeks. It has been suggested that microgravity affects bone metabolism, however, the mechanism remains unknown. The purpose of this study is to clarify the mechanism of microgravity effects on cultured osteoblasts. The investigation is focused on the gene expression and cell productivity, cytokines, growth factors, and bone matrix proteins. Gene expression was analyzed by quantitative Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR), whereas differentiated function of osteoblasts was investigated by quantitating cellular products using enzyme immunoassay or radioimmunoassay. The cellular products which were secreted into the culture medium were harvested during space flight and analyzed quantitatively after return to the earth. In microgravity, prostaglandin E2 production was increased by two- to ten-fold, whereas osteocalcin productivity was inhibited by 60 to 90 percent. Prostaglandin E2 is reported to activate on osteoclast induction, whereas osteocalcin is reported to play some role in hydroxyapatite crystal formation as the bone matrix protein. The changes of cellular productivity were consistent with changes in mRNA (m Ribonucleic Acid) levels for prostaglandin E2 and osteocalcin synthesis. These results suggest that microgravity affects differentiated function of osteoblasts at the transcriptional level and that the changes of the cellular products will then induce bone demineralization in microgravity.
骨由来培養細胞の増殖・分化機能発現に及ぼす微小重力の影響(OSTEOGENE)
00271005.pdf
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