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.

Emodin prevents intima thickness via Wnt4/Dvl-1/ß-catenin signaling pathway mediated by miR-126 in balloon-injured carotid artery rats.

Neointimal proliferation after vascular injury is a key mechanism of restenosis, a major cause of percutaneous transluminal angioplasty failure and artery bypass occlusion. Emodin, an anthraquinone with multiple physiological activities, has been reported to inhibit proliferation of vascular smooth muscle cells (VSMCs) that might cause intimal arterial thickening. Thus, in this study, we established a rat model of balloon-injured carotid artery and investigated the therapeutic effect of emodin and its underlying mechanism. Intimal thickness was analyzed by hematoxylin and eosin staining. Expression of Wnt4, dvl-1, ß-catenin and collagen was determined by immunohistochemistry and/or western blotting. The proliferation of VSMC was evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and electron microscopy. MicroRNA levels were quantified by real-time quantitative PCR. Emodin relieved injury-induced artery intimal thickness. Results of western blots and immunohistochemistry showed that emodin suppressed expression of signaling molecules Wnt4/Dvl-1/ß-catenin as well as collagen protein in the injured artery. In addition, emodin enhanced expression of an artery injury-related microRNA, miR-126. In vitro, MTT assay showed that emodin suppressed angiotensin II (AngII)-induced proliferation of VSMCs. Emodin reversed AngII-induced activation of Wnt4/Dvl-1/ß-catenin signaling by increasing expression of miR-126 that was strongly supported by transfection of mimic or inhibitor for miR-126. Emodin prevents intimal thickening via Wnt4/Dvl-1/ß-catenin signaling pathway mediated by miR-126 in balloon-injured carotid artery of rats.

[Precise minimally invasive surgery of lower lumbar spine].

The fast development of minimally invasive spine surgery in recent years is based on the advance of endoscopic microsurgery techniques, computer science and medical imaging, as well as the growing concerning of medical humanities. The concept of minimally invasive and precise targeting therapy has been penetrating into various areas of surgery, and minimal tissue damage and fewer complications are the new directions of minimally invasive spine surgery. In this article we review some advances in precise spinal surgery including percutaneous lumbar discectomy, microendoscopic discectomy, computer-assisted orthopedic surgery and robot surgery.

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.