Antiapoptotic Effect of Gene Therapy with Recombinant Adenovirus Vector Containing Hypoxia-inducible Factor-1α after Cerebral Ischemia and Reperfusion in Rats

Background：Mounting evidence has demonstrated that hypoxia-inducible factor-1α （HIF-1α） could attenuate brain injuries after cerebral ischemia and reperfusion （CIR）.However,few reports have addressed the therapeutic efficacies of a recombinant adenovirus vector containing HIF-1o （AdHIF-1o） gene after ischemia and reperfusion.The aim of this study was to examine the antiapoptotic and neuroprotective effects ofAdHIF-1o gene for cerebral injuries after ischemia and reperfusion in rats.Methods：From February to December 2016,male Sprague-Dawley rats were randomly divided into normal,sham,CIR,AdHIF-1α,and recombinant adenovirus （Ad） groups.Middle cerebral artery occlusion model was established by Longa＇s method and reperfusion resumed at 2 h postocclusion.AdHIF-1α solution,Ad solution,and phosphate-buffered saline were injected into the right lateral ventricle of rats in AdHIF-lα,Ad,and CIR groups.Brain tissue sections were observed under fluorescent microscope to confirm the definite expression of recombinant adenovirus in Ad and AdHIF-1o groups.The expressions of HIF-lα protein were analyzed by immunohistochemical staining at 6 h,24 h,and 72 h postreperfusion.Brain water content and neurological deficit scores were evaluated at 6 h,24 h,and 72 h postreperfusion.Pathological brain injuries were examined after hematoxylin and eosin stain and nerve cell apoptosis was measured after terminal-deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling （TUNEL） stain at 72 h postreperfusion.Comparisons were conducted with one-way analysis of variance by post hoc Scheffe＇s test among different experimental groups.Results：Green fluorescent protein was successfully expressed in brain tissue ofAd andAdHIF-1α groups from 24 h to 21 days postinjection.As detected by immunohistochemical staining,the expressions of HIF-lα protein were obviously enhanced in AdHIF-1o group than those in CIR and Ad groups at 24 h and 72 h postreperfusion,respectively.There were significant reductions of brain water content （78.83% ± 0.34% vs.83.21% ± 0.50% and 83.35% ± 0.32%;84.13% ± 0.24% vs.89.76% ± 0.34% and 89.70% ± 0.18%;respectively;all P 〈 0.05） and neurological deficit scores （2.90 ± 0.74 vs.3.50 ± 0.52 and 3.60 ± 0.53 at 24 h;2.40 ± 0.84 vs.3.60 ± 0.52 and 3.50 ± 0.53 at 72 h;respectively;all P 〈 0.05） in AdHIF-1 α group versus CIR and Ad groups at 24 h and 72 h postreperfusion,respectively.The pathologic changes ofAdHIF-1 α group were milder than those in CIR and Ad groups at 72 h postreperfusion.The percentage of TUNEL-positive cells in cerebral subcortex decreased significantly in AdHIF-1α group versus CIR and Ad groups at 72 h postreperfusion （P 〈 0.05）.Conclusion：AdHIF-1α has an obvious neuroprotective effect on ischemia and reperfusion in rat brains possibly through inhibiting the apoptosis of nerve cells.

Inhibition of vascular smooth muscle cell proliferation by in troduction of retinoblastoma gene via a recombinant adenovirus vector

This study was supported in part by grant from National Natural Science Foundation of China (No. 39570775). Objective To investigate the vascular smooth muscle cell (SMC) growth suppression by recombinant adenovirus vector expressing a retinoblastoma (Rb) protein and to explore a gene therapy approach for vascular proliferative disorders including atherosclerosis and artery restenosis. Methods A replication deficient adenovirus vector encoding a wild type Rb and AdCMVRb, was constructed and transfected into cultured rabbit aortic SMC. The efficiency of gene transfection and expression was detected by immunochemical staining and polymerase chain reaction. The role of Rb in regulating vascular SMC proliferation was observed by cell counting, thymidine incorporation, and flow cytometry. Results Wild type Rb gene transfected effectively into the cultured SMC with AdCMVRb can suppress growth factor stimulated cell proliferation through regulation of DNA synthesis and cell cycle progression. Conclusion The results demonstrate the potential of adenovirus mediated Rb gene therapy for atherosclerosis and artery restenosis after balloon angioplasty.

Gene transfer into primary cultures of fetal neural stem cells by a recombinant adenovirus carrying the gene for green fluorescent protein

Objective: To evaluate the transduction efficiency of a recombinant adenovirus carrying the gene for green fluorescent protein (Ad-GFP) into the primary cultures of fetal neural stem cells (NSCs) by the expression of GFP. Methods: The Ad-GFP was constructed by homologous recombination in bacteria with the AdEasy system; NSCs were isolated from rat fetal hippocampus and cultured as neurosphere suspensions. After infection with the recombinant Ad-GFP, NSCs were examined with a fluorescent microscopy and a flow cytometry for their expression of GFP. Results: After the viral infection, flow cytometry analysis revealed that the percentage of GFP-positive cells was as high as 97.05%. The infected NSCs sustained the GFP expression for above 4 weeks. After differentiated into astrocytes or neurons, they continued to express GFP efficiently. Conclusion: We have success- fully constructed a viral vector Ad-GFP that can efficiently infect the primary NSCs. The reporter gene was showed fully and sustained expression in the infected cells as well as their differentiated progenies.

Transfection of the glial cell line-derived neurotrophic factor gene promotes neuronal differentiation

Glial cell line-derived neurotrophic factor recombinant adenovirus vector-transfected bone marrow mesenchymal stem cells were induced to differentiate into neuron-like cells using inductive medium containing retinoic acid and epidermal growth factor. Cell viability, micro- tubule-associated protein 2-positive cell ratio, and the expression levels of glial cell line-derived neurotrophic factor, nerve growth factor and growth-associated protein-43 protein in the su- pernatant were significantly higher in glial cell line-derived neurotrophic factor/bone marrow mesenchymal stem cells compared with empty virus plasmid-transfected bone marrow mes- enchymal stem cells. Furthermore, microtubule-associated protein 2, glial cell line-derived neurotrophic factor, nerve growth factor and growth-associated protein743 mRNA levels in cell pellets were statistically higher in glial cell line-derived neurotrophic factor/bone marrow mesen- chymal stem cells compared with empty virus plasmid-transfected bone marrow mesenchymal stem cells. These results suggest that glial cell line-derived neurotrophic factor/bone marrow mesenchymal stem cells have a higher rate of induction into neuron-like cells, and this enhanced differentiation into neuron-like cells may be associated with up-regulated expression of glial cell line-derived neurotrophic factor, nerve growth factor and growth-associated protein-43.