Objective To investigate the role of endothelial progenitor cells transfected with lentivirus overex-pressing hepatocyte growth factor in repairing sciatic nerve injury in rats.Methods In vitro experiments,rat bone mar-row endothelial progenitor cells(EPC)were extracted and identified using DiI-acLDL and FITC-UEA-1 double stai-ning.qRT-PCR detected the gene expression level after EPC were transfected with lentivirus.CCK-8 assay,Transwell as-say,and tube formation assay were used to evaluate the function of EPC in vitro.In vivo experiments,25 SD rats were randomly divided equally into 5 groups,i.e.,the blank group(Con group),the normal EPC group(N-EPC group),the empty virus-transfected EPC group(LV-NC group),the overexpression of HGF virus-transfected EPC group(LV-HGF group),and the sham operation group.After exposing the right sciatic nerve in each group of rats,a 2-mm-wide sciatic nerve crush injury was formed by using hemostatic forceps 10 mm above the bifurcation of the sciatic nerve;the sham-op-erated group was left untreated after exposing the nerve.After surgery,EPC transfected with empty lentivirus,EPC trans-fected with lentivirus overexpressing HGF,or normal EPC mixed with matrigel at a 1:1 volume ratio were respectively in-jected into the neuroepithelium of the nerves,whereas no EPC were injected into the blank group.Four weeks after sur-gery,Catwalk was used to detect the recovery of motor function in rats,electrophysiological tests to detect the recovery of nerve conduction function,transmission electron microscopy to observe the thickness of myelin sheaths,toluidine blue staining to observe the density of nerve fibers,Matson staining to detect the area of gastrocnemius muscle fibers,and gas-trocnemius muscle wet weight weighing to detect the degree of muscle atrophy.Results Compared with normal EPC,EPC in the LV-HGF group had faster cell proliferation in the CCK8 assay(P＜0.05),higher cell migration rate in the Transwell assay(P＜0.01),and formed more vessel-like structures in the tube formation assay(P＜0.01);the sciatic nerve function index values of the LV-HGF group were significantly higher than those of the other three groups(Con group,P＜0.01;N-EPC group,P＜0.01;LV-NC group,P＜0.01);the compound muscle action potential amplitude was higher(Con group,P＜0.01;N-EPC group,P＜0.05;LV-NC group,P＜0.05);thicker myelin sheaths in regenerating sciatic nerves(Con group,P＜0.01;N-EPC group,P＜0.01;LV-NC group,P＜0.01);higher densities of myelinated nerve fibers(Con group,P＜0.01;N-EPC group,P＜0.05;LV-NC group,P＜0.05);and higher wet-to-weight ratios of gastrocnemius muscles(Con group,P＜0.01;N-EPC group,P＜0.01;LV-NC group,P＜0.01);and a larger mean area of muscle fibERs(Con group,P＜0.01;N-EPC group,P＜0.05;LV-NC group,P＜0.05);however,the above experi-mental results were still significantly different from the sham-operated group(P＜0.01).Conclusions Overexpression of the HGF gene could enhance the proliferation,migration,and differentiation functions of EPC.After sciatic nerve crush injury,EPC transfected with the HGF gene promotes the restoration of damaged peripheral nerve structure and function more significantly compared with normal EPC.The mechanism is related to the promotion of axon regeneration and mye-lin sheath formation in damaged peripheral nerves.
维普
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