Treatment of Femoral Head Necrosis With Bone Marrow Mesenchymal Stem Cells Expressing Inducible Hepatocyte Growth Factor.

Our study assessed the effect of bone marrow mesenchymal stem cells (BMSCs) expressing inducible hepatocyte growth factor (HGF) on the recovery of femoral head necrosis (FHN). BMSCs were isolated by density gradient centrifugation. A recombinant AdTRE-HGF was constructed as the response plasmid and Adeno-X Tet-on as the regulator vector. The regulator and the response vectors were coinfected into BMSCs and induced at 0, 200, 500, 1000, and 1200 ng/mL doxycycline (Dox). After 3 days, the concentration of HGF was determined using enzyme-linked immunosorbent assay. Forty rabbits were selected to establish the FHN model and divided into 4 experimental groups. After the rabbits were killed by ketamine overdose, the restoration of FHN was assessed. The distribution of HGF-positive cells was observed by immunohistochemical method. Enzyme-linked immunosorbent assay results showed that 1000 ng/mL Dox induced the highest HGF expression level, even higher than the 1200 ng/mL Dox induction. The highest osteonecrosis incidence and empty lacunae percentage were found in group A compared with all the other groups (all P < 0.05). Furthermore, dramatically lower osteonecrosis incidence and empty lacunae percentage were found in group C compared with those of groups B and D (all P < 0.05). A significantly higher level of HGF protein was detected in group C compared with the other groups (all P < 0.05). Our study successfully developed the AdTRE-HGF, a recombinant adenovirus carrying HGF gene, for high expression of HGF in BMSCs. Importantly, introduction of BMSCs expressing HGF successfully produced the desired therapeutic effect in reversing FHN, in a Dox-dependent manner.