Src inhibitor reduces permeability without disturbing vascularization and prevents bone destruction in steroid-associated osteonecrotic lesions in rabbits

To examine the therapeutic effect of Src inhibitor on the VEGF mediating vascular hyperpermeability and bone destruction within steroid-associated osteonecrotic lesions in rabbits. Rabbits with high risk for progress to destructive repair in steroid-associated osteonecrosis were selected according to our published protocol. The selected rabbits were systemically administrated with either Anti-VEGF antibody (Anti-VEGF Group) or Src inhibitor (Src-Inhibition Group) or VEGF (VEGF-Supplement Group) or a combination of VEGF and Src inhibitor (Supplement and Inhibition Group) or control vehicle (Control Group) for 4 weeks. At 0, 2 and 4 weeks after administration, in vivo dynamic MRI, micro-CT based-angiography, histomorphometry and immunoblotting were employed to evaluate the vascular and skeletal events in different groups. The incidence of the destructive repair in the Anti-VEGF Group, Src-Inhibition Group and Supplement and Inhibition Group was all significantly lower than that in the Control Group. The angiogenesis was promoted in VEGF-Supplement Group, Src-Inhibition Group and Supplement and Inhibition Group, while the hyperpermeability was inhibited in Anti-VEGF Group, Src-Inhibition Group and Supplement and Inhibition Group. The trabecular structure was improved in Src-Inhibition Group and Supplement and Inhibition Group. Src inhibitor could reduce permeability without disturbing vascularization and prevent destructive repair in steroid-associated osteonecrosis.