Fig 1.
Illustration of the tail ring (A), and steel wires with tape (B) as applied to the tail for the suspension studies. Also shown are the three different housing conditions; normal housing (C), non suspended housing (D), and suspended housing (E) using terminated immobile mice to show angles of suspension as active mice in non suspended housing (F) and suspended (G) are difficult to photograph. The food blocks were clamped (black boxes) to allow access but to prevent movement of food block for resting of hindlimbs.
Fig 2.
Trabecular and cortical bone regions analyzed by microCT.
Trabecular bone microarchitecture was analyzed below the growth plate. 1.2mm was analyzed, which represents 63 slices in vivo (19 μm) and 120 slices ex vivo (10 μm voxel size). Cortical bone microarchitecture was analyzed below the growth plate (1mm analyzed representing 53 slices in vivo and 100 slices ex vivo) and above the tibia-fibula junction (0.5mm analyzed representing 26 sections in vivo and 50 sections -ex vivo).
Fig 3.
Body weight change for 3 different housing conditions and 2 genotypes.
Ctrl: Control, HET: Dmp1 Cre x β-catenin heterozygotes, NH: Normal Housing, NS: Non Suspended, SUS: Suspended. Number of animals per group = 5–8. *: represents a significant difference between two groups (p<0.05). One-way Analysis of Variance was used to assess the differences between the groups followed by pairwise post hoc tests.
Fig 4.
Corticosterone levels for 3 different housing conditions and 2 genotypes.
Ctrl: Control, HET: Dmp1 Cre x β-catenin heterozygotes, NH: Normal Housing, NS: Non Suspended, SUS: Suspended. Number of animals per group = 5–8. *: represents a significant difference between two groups (p<0.05). One-way Analysis of Variance was used to assess the differences between the groups followed by pairwise post hoc tests.
Table 1.
Bone phenotype of Control mice (Ctrl) as compared to β-catenin conditional knock-out heterozygous mice (cKO HET) at 14 weeks (in vivo) and 19 weeks (ex vivo).
Fig 5.
Effects of environment and suspension on 19 week old control and cKO HET male mice.
Cortical bone mineral density (BMD), bone volume (BV/TV) and cortical thickness (Ct.Th) were analyzed at the diaphysis and at the metaphysis as shown in the Fig 2. Trabecular bone mineral density (BMD), bone volume (BV/TV), number (Tb.N), thickness (Tb.Th) and spacing (Tb.Sp) were analyzed at the metaphysis. *significant difference between NH and NS and between NS and SUS (p<0.05). One-way Analysis of Variance was used to assess the differences between the groups followed by pairwise post hoc tests. Number of animals per group = 5–7.
Fig 6.
Effects of environment and suspension on 19 week old control and cKO HET female mice.
Cortical bone mineral density (BMD), bone volume (BV/TV) and cortical thickness (Ct.Th) were analyzed at the diaphysis and at the metaphysis as shown in the Fig 2. Trabecular bone mineral density (BMD), bone volume (BV/TV), number (Tb.N), thickness (Tb.Th) and spacing (Tb.Sp) were analyzed at the metaphysis. *significant difference between NS and SUS (p<0.05). One-way Analysis of Variance was used to assess the differences between the groups followed by pairwise post hoc tests. Number of animals per group = 5–7.
Table 2.
Osteoclast activity as measured by TRAP staining after sacrifice at 19 weeks.