Gussekloo_etal_Fenestration_Evolution

Finite Element Models in ANSYS format and measurement data of the in vivo experiment. For further information, please see included README files

Decreased bone strength in TTD mice.

<p>Bone strength, mineralization, perimeter, MOI and bone formation rates in long bones of aging wild type (solid bars or symbols) and TTD males (open bars or symbols). (A) Energy to failure (B) Ultimate load (C) Bone stiffness, (D) bone mineralization, (C) MOI and (D) perimeter (Pm.). Statistics: a= student t-test; p<0.05 wild type vs. TTD, b−d = 2 way ANOVA; p<0.05. b= significant difference between wild type and TTD with aging, c= signifcant difference with aging within a genotype, d= a significant interaction between age and genotype. Error bars represent SEM.</p

Periosteal apposition, bone formation and hormone levels.

<p>TTD mice lack periosteal apposition at 78 weeks whereas endosteal apposition is not affected. Calcein labelling at sites of periosteal apposition in 78-week-old (A) wild type and (B) TTD mice. Quantitative analyses of (C) periosteal and (D) endosteal apposition at 13 and 78 weeks. Serum measurements of bone formation markers and hormones; (E) osteocalcin, (F) leptin, (G) glucose at 26 and 52 weeks. Statistics: student t-test a = p<0.05 wild type vs. TTD. Error bars represent SEM.</p

Histomorphometric analyses.

<p>Histomorphometric parameters were measured in 13 and 78 week old wild type and TTD tibiae (N=5). T-tests were performed at each time point, p-values are depicted in the table in the columns “p-value". Interaction between the age and phenotype of the mice was determined by performing 2-way ANOVA’s, p-values are depicted in the table in the column “Interaction". * = significant difference between wild type and TTD bones, p<0.05.</p

Regulation of gene expression levels in tibiae.

<p>Expression levels measured in RNA extracted from tibiae of 13 and 52 week old wild type and TTD mice; (A) osteoblast marker genes <i>Bglap</i> and <i>Col1A1</i>. (B) Osteoclast marker genes <i>Acp5</i> and <i>Ctsk</i>, (C) stress regulated genes <i>Foxo1, Foxo3</i> and <i>Foxo4</i>, (D) antioxidant enzyme scavengers <i>Sod1, Sod2</i> and <i>Sod3</i>. Statistics: student t-test a = p<0.05 wild type vs. TTD, b = p<0.05 time point x vs. time point 13 weeks within one genotype.</p

Mesenchymal and hematopoietic stem cell differentiation.

<p>Mesenchymal and hematopoietic stem cell differentiation in aging wild type (solid bars) and TTD males (open bars). (A) Average number of ALP⁺ colonies in ex vivo bone marrow cultures after 14 days of culture. (B) Average colony size at day 14 of culture. (C) The average number of adipocytes per well. (D) Average number of TRAP+ positive cells per picture. (E) Average number of mature osteoclasts per picture. (F) Average percentage resorption surface per osteoclast pit per mature osteoclast. Statistics: a= student t-test; p<0.05 wild type vs. TTD, b−d = 2 way ANOVA; p<0.05. b= significant difference between wild type and TTD with aging, c= signifcant difference with aging within a genotype, d= a significant interaction between age and genotype. Error bars represent SEM.</p

Age-related trabecular bone loss in male TTD mice.

<p>Trabecular bone parameters (A-D) were studied in aging wild type (solid) and TTD (open) tibial metaphyses. (A) Trabecular bone volume fraction (BV/TV), (B) Endocortical volume (Ec.V.), (C) Trabecular number (Tb.N.), (D) Trabecular thickness (Tb.Th.). 100 cross-sections were measured in the metaphysis of TTD and wild type mice. Representative cross-sections of 26 week old, male, wild type (E) and TTD mice (F) depict the loss of trabecular bone, the decrease in trabecular number and increase in endocortical volume. Statistics: a= student t-test; p<0.05 wild type vs. TTD, b−d = 2 way ANOVA; p<0.05. b= significant difference between wild type and TTD with aging, c= signifcant difference with aging within a genotype, d= a significant interaction between age and genotype. Error bars represent SEM.</p

Age-related cortical bone loss in male TTD mice.

<p>Cortical bone parameters (A-D) were studied in aging wild type (solid) and TTD (open) tibial diaphyses.(A) Cortical thickness (Ct.Th.), (B) cortical volume (Ct.V.), (C) endocortical volume (Ec.V.), (D) 3D thickness distribution. Figures E and F depict the significant decrease in cortical thickness when comparing 26 week old wild type (E) and TTD (F) mice. Statistics: a= student t-test; p<0.05 wild type vs. TTD, b−d = 2 way ANOVA; p<0.05. b= significant difference between wild type and TTD with aging, c= signifcant difference with aging within a genotype, d= a significant interaction between age and genotype. Error bars represent SEM.</p