Abstract Fracture healing in animal models has been shown to be altered in both ground based analogs of spaceflight and in those exposed to actual spaceflight. The molecular mechanisms behind altered fracture healing as a result of chronic exposure to microgravity remain to be elucidated. This study investigates temporal gene expression of multiple factors involved in secondary fracture healing, specifically those integral to the development of a soft tissue callus and the transition to that of hard tissue. Skeletally mature female rats were subjected to a 4 week period of simulated microgravity and then underwent a closed femoral fracture procedure. Thereafter, they were reintroduced to the microgravity and allowed to heal for a 1 or 2 week period. A synchronous group of weight bearing rats was used as a normal fracture healing control. Utilizing Real-Time quantitative PCR on mRNA from fracture callus tissue, we found significant reductions in the levels of transcripts associated with angiogenesis, chondrogenesis, and osteogenesis. These data suggest an altered fracture healing process in a simulated microgravity environment, and these alterations begin early in the healing process. These findings may provide mechanistic insight towards developing countermeasure protocols to mitigate these adaptations.
Highlights ► Hind limb unloading (HLU) delays early stages of long bone fracture healing. ► HLU reduced angiogenesis gene expression during early fracture healing stages. ► HLU reduced Type II collagen gene expression during early fracture healing stages. ► HLU reduced osteoinductive gene expression during early fracture healing stages. ► HLU reduced osteogenic gene expression during early fracture healing stages.
Simulated microgravity alters the expression of key genes involved in fracture healing
Acta Astronautica ; 92 , 1 ; 65-72
2012-04-09
8 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
PCR , polymerase chain reaction , VEGF , vascular endothelial growth factor , FGF2 , basic fibroblast growth factor , IGF-1 , insulin like growth factor-1 , PDGF , platelet derived growth factor , TGF-β , transforming growth factor-β , BMPs , bone morphogenetic proteins , HLU , hind limb unloaded , WB , weight bearing , micro-CT , micro-computed tomography , MSCs , mesenchymal stem cells , ROI , region of interest , Simulated microgravity , Fracture healing , Gene expression , Angiogenesis , Chondrogenesis , Osteogenesis
Simulated microgravity alters the expression of key genes involved in fracture healing
Online Contents | 2013
|Low-shear modelled microgravity alters expression of virulence determinants of Staphylococcus aureus
Online Contents | 2010
|