Figure 3.
Ablation of Tsc1 in MSCs Increased Bone Mass but Reduced Bone Quality
(A) Ablation of Tsc1 in Prx1+ MSCs increased the cortical thickness of femur bones to a greater extent than ablation of Tsc1 in Dermo1+ or Osx+ OBs. N = 4 mice.
(B) Micro-CT analysis revealed that Prx1-Cre; Tsc1f/f mice showed a greater increase in trabecular bone volume than Dermo1-Cre; Tsc1f/f and Osx-Cre; Tsc1f/f mice. N = 4 mice.
(C–G) Prx1-Cre; Tsc1f/f mice showed an increase in thickness (C) and the number (D), and a decrease in separation (E) of trabecular bones, and an increase in bone formation rate (BFR) (F) and mineral apposition rate (MAR) (G). N = 4 mice.
(H) Prx1-Cre; Tsc1f/f mice femur cortical bones appeared to be porous, some of which were stained positive for CD31. Black arrow, pores; red arrow, blood vessel. Scale bars, 200 μm (upper panel) and 50 μm (lower panel).
(I) von Kossa staining of Prx1-Cre; Tsc1f/f and control littermates showed that the mineralization was impeded in the mutant mouse bones. Scale bar, 200 μm.
(J) Masson staining of Prx1-Cre; Tsc1f/f and control littermates showed that the mineralization was impeded in the mutant mouse bones. Scale bar, 50 μm.
(K) Prx1-Cre; Tsc1f/f mice showed reduced bone strength, judged by the three-point bending experiment results. N = 4 mice.
Error bars represent the SD. ∗p < 0.05; ∗∗p < 0.01.