Effect of simulated weightlessness on osteoprogenitor cell number and proliferation in young and adult rats
Abstract
Experiments with rats flown in space or hind limb unloaded (HU) indicate that bone loss in both conditions is associated with a decrease in bone volume and osteoblast surface in cancellous and cortical bone. We hypothesize that the decrease in osteoblastic bone formation and osteoblast surface is related to a decrease in the number of osteoprogenitors and/or decreased proliferation of their progeny. We tested this hypothesis by evaluating the effect of 14 days of HU on the number of osteoprogenitors (osteoblast colony forming units; CFU-O), fibroblastic colony forming units (CFU-F), and alkaline phosphatase-positive CFU (CFU-AP) in cell populations derived from the proximal femur (unloaded) and the proximal humerus (normally loaded) in 6-week-old and 6-month-old rats. To confirm the effect of unloading on bone volume and structure, static histomorphometric parameters were measured in the proximal tibial metaphysis. Effects of HU on proliferation of osteoprogenitors were evaluated by measuring the size of CFU-O. HU did not affect the total number of progenitors (CFU-F) in young or adult rats in any of the cell populations. In femoral populations of young rats, HU decreased CFU-O by 71.0% and mean colony size was reduced by 20%. HU decreased CFU-AP by 31.3%. As expected, no changes in CFU-O or CFU-AP were seen in cell populations from the humerus. In femoral cell populations of adult rats, HU decreased CFU-O and CFU-AP by 16.6% and 36.6%, respectively. Again, no effects were…
Read the paper
Related studies
- Irisin Enhances Osteoblast DifferentiationIn Vitro
- Glucocorticoids suppress Wnt16 expression in osteoblasts in vitro and in vivo
- Interaction between Schwann Cells and Osteoblasts In Vitro
- Administration of cinnamaldehyde promotes osteogenesis in ovariectomized rats and differentiation of osteoblast in vitro
- The Effect of the Major Components of Fructus Cnidii on Osteoblasts In Vitro
- Estrogen depletion alters osteogenic differentiation and matrix production by osteoblasts in vitro
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.