npj Microgravity (Jul 2024)

Growth and mineralization of fetal mouse long bones under microgravity and daily 1 g gravity exposure

  • Jack J. W. A. van Loon,
  • Olga P. Berezovska,
  • Theodorus J. M. Bervoets,
  • Dina Montufar-Solis,
  • Cor M. Semeins,
  • Behrouz Zandieh-Doulabi,
  • P. Natalia V. Rodionova,
  • Jackie Duke,
  • J. Paul Veldhuijzen

DOI
https://doi.org/10.1038/s41526-024-00421-4
Journal volume & issue
Vol. 10, no. 1
pp. 1 – 9

Abstract

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Abstract In a previous Space Shuttle/Spacelab experiment (STS-42), we observed direct responses of isolated fetal mouse long bones to near weightlessness. This paper aimed to verify those results and study the effects of daily 1×g exposure during microgravity on the growth and mineralization of these bones. Two experiments were conducted: one on an American Space Shuttle mission (IML-2 on STS-65) and another on a Russian Bio-Cosmos flight (Bion-10 on Cosmos-2229). Despite differences in hardware, both used 17-day-old fetal mouse metatarsals cultured for 4 days. Results showed reduced proteoglycan content under microgravity compared to 1×g conditions, with no main differences in other cellular structures. While the overall metatarsal length was unaffected, the length increase of the mineralized diaphysis was significantly reduced under microgravity. Daily 1×g exposure for at least 6 h abolished the microgravity-induced reduction in cartilage mineralization, indicating the need for long-duration exposure to 1×g as an in-flight countermeasure using artificial gravity.