Regulation of expression of HGF in BM-MSCs by baculovirus-mediated transduction

Bone marrow-derived mesenchymal stem cells (BM-MSCs) transplantation is widely adopted for the curing of osteonecrosis of femoral head (ONFH) in recent years. Furthermore, it is known that introducing hepatocyte growth factor (HGF) into BM-MSCs will greatly improve the therapeutic effect of stem-cell therapy owing to the great angiogenic and anti-fibrotic capabilities of HGF. However, continuing overexpression of HGF in vivo may cause sarcomas, such as Kaposi's sarcoma. Aiming at enhancing the therapeutic effect and preventing the side effects of HGF-modified stem-cell transplantation on ONFH, we sought to construct a gene regulation system to control HGF expression in BM-MSCs rigorously and accurately. We selected baculovirus as the gene vector and introduced pTet-on advanced system into that. Finally, a virus vector vAc(rtTA2s-Ptight-HGF) was successfully built and delivered into BM-MSCs to regulate the accurate expression of HGF. As shown in the results, different levels of HGF expression were verified by ELISA and Western blot with different induction doses of doxycycline (DOX). There was a dose-response relationship between them, and the optimum dose of DOX to induce HGF expression in BM-MSCs in vitro was 1 µg/mL. We conclude that it is feasible to regulate HGF expression in BM-MSCs by baculovirus-mediated one-off transduction.