Microgravity signal ensnarls cell adhesion, cytoskeleton, and matrix proteins of rat osteoblasts: osteopontin, CD44, osteonectin, and alpha-tubulin.
Rat osteoblasts were cultured for 4 or 5 days aboard the Space Shuttle and solubilized during spaceflight. Post-flight analyses by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) determined the relative mRNA levels of matrix proteins, adhesion molecules, and cytoskeletal proteins including osteopontin (OP), osteonectin (ON), CD44, alpha-tubulin, actin, vimentin, fibronectin (FN), and beta1-integrin. The mRNA levels of OP and alpha-tubulin in the flight cultures were decreased by 30% and 50% on day 4 and day 5 of flight, as compared to the ground controls. In contrast, the CD44 mRNA levels in the flight cultures increased by 280% and 570% of the ground controls on day 4 and day 5. The mRNA levels of ON and FN in the flight cultures were slightly increased as compared to ground controls. The mRNA levels of actin, vimentin, or beta1-integrin did not change in spaceflight conditions. The matrix proteins, adhesion molecules, and cytoskeletal proteins may form dynamic network complexity with signaling molecules as an adaptive response to perturbation of mechanical stress under microgravity.
Kumei
Yasuhiro
Y
Department of Hard Tissue Engineering, Section of Biochemistry, Graduate School of Tokyo Medical and Dental University, Tokyo 113-8549, Japan. kumei.bch@tmd.ac.jp
Morita
Sadao
S
Katano
Hisako
H
Akiyama
Hideo
H
Hirano
Masahiko
M
Oyha
Kei'ichi
K
Shimokawa
Hitoyata
H
D000818:Animals; D001483:Base Sequence; D002448:Cell Adhesion; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism*; D017931:DNA Primers; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism*; D005353:Fibronectins / Q000235:genetics / Q000378:metabolism; D018960:Hyaluronan Receptors / Q000235:genetics / Q000378:metabolism; D019012:Integrin beta1 / Q000235:genetics / Q000378:metabolism; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism*; D015676:Osteonectin / Q000235:genetics / Q000378:metabolism; D053495:Osteopontin / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D014404:Tubulin / Q000235:genetics / Q000378:metabolism; D014746:Vimentin / Q000235:genetics / Q000378:metabolism; D014893:Weightlessness
D003598:Cytoskeletal Proteins; D017931:DNA Primers; D016326:Extracellular Matrix Proteins; D005353:Fibronectins; D018960:Hyaluronan Receptors; D019012:Integrin beta1; D015676:Osteonectin; D012333:RNA, Messenger; D014404:Tubulin; D014746:Vimentin; D053495:Osteopontin