Prednisolone and AAV8-Ostn induce osteocyte apoptosis and TRAP expression in cortical bone
(A) Osteocrin mRNA expression was measured by in situ hybridization in AAV8-Control-treated cortical bone. Signal was semi-quantitatively analyzed but not statistically compared (n = 5). Arrows indicate signal in periosteum. Scale bar = 50 μm.
(B) Tartrate-resistant acid phosphatase (TRAP) expression was quantified as the number of positively stained osteocytes per cortical bone area. Images show AAV8-Control groups. Scale bar = 50 μm.
(C) Proportion of empty osteocyte lacunae was counted in hematoxylin and eosin-stained cortical bone. Images show AAV8-Control groups. Scale bar = 50 μm.
(D) Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) was used to quantify apoptotic osteocytes in cortical bone (one outlier removed from placebo + AAV8-Control group and one outlier removed from prednisolone + AAV8-Control group). Scale bar = 20 μm. Images show AAV8-Control groups. n = 7-10. ∗p < 0.05 compared to the corresponding placebo group by Sidak’s multiple comparisons tests. All error bars show +/− SD.