Dietary countermeasure mitigates simulated spaceflight-induced osteopenia in mice

Sonette Steczina,Ons M’Saad,Moniece Lowe,Ruth K Globus,Megan Pendleton,Candice G T Tahimic,Bernard P Halloran,Joshua S Alwood,Ann-Sofie Schreurs

doi:10.1038/s41598-020-63404-x

Abstract

Spaceflight is a unique environment that includes at least two factors which can negatively impact skeletal health: microgravity and ionizing radiation. We have previously shown that a diet supplemented with dried plum powder (DP) prevented radiation-induced bone loss in mice. In this study, we investigated the capacity of the DP diet to prevent bone loss in mice following exposure to simulated spaceflight, combining microgravity (by hindlimb unloading) and radiation exposure. The DP diet was effective at preventing most decrements in bone micro-architectural and mechanical properties due to hindlimb unloading alone and simulated spaceflight. Furthermore, we show that the DP diet can protect osteoprogenitors from impairments resulting from simulated microgravity. Based on our findings, a dietary supplementation with DP could be an effective countermeasure against the skeletal deficits observed in astronauts during spaceflight.

Highlights

Spaceflight is a unique environment that includes at least two factors which can negatively impact skeletal health: microgravity and ionizing radiation
Our lab has reported that mice fed a diet composed of Dried Plum (DP) prevented cancellous bone loss caused by ionizing radiation (IR), both low-linear energy transfer (LET) such as gamma (137Cs) and a mixture of both low-LET and high-LET
Mice were assigned to the following groups at the start of the experiment: normally loaded (NL) or hindlimb unloaded (HU) for a total of 14 days at 16 weeks of age, with either sham radiation or IR exposure on day 3

Summary

Introduction

Spaceflight is a unique environment that includes at least two factors which can negatively impact skeletal health: microgravity and ionizing radiation. Hindlimb unloading (HU) is widely used to simulate the effects of the microgravity environment in rodents[46] This model allows for a simulation of the cephalad fluid shift[47] and removal of load-bearing forces typically experienced by the hindlimbs, which can lead to increased numbers of bone-resorbing osteoclasts and decreased numbers of bone-forming osteoblasts[48]. Together, these events result in bone loss as well as reduced bone mechanical properties in rodents[49,50,51,52]. The ability to maintain bone homeostasis is diminished[16,54,55,56]

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Results

Conclusion