Preliminary research on the regeneration of injured rabbit vocal folds after the transplantation of human amniotic epithelial cells / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the survival, growth and distribution of human amniotic epithelial cells (hAEC) after injected into injured rabbit vocal folds, in addition, to assess the ability of hAEC to affect the components of lamina propria extracellular matrix (ECM) and prevent vocal fold scarring.</p><p><b>METHODS</b>hAEC were isolated from human amnion and marked by Lenti-EGFP. Fifteen New Zealand rabbits were used for this experiment. EGFP-hAEC was injected into the left injured vocal folds in thirteen rabbits, and the contralateral thirteen vocal folds experienced an injured procedure only ("injured untreated control"), and four vocal folds were left as untreated controls. The survival, distribution, differentiation potential and secretion function of hAEC were examined by immunofluorescence method. HE staining and immunohistochemical staining were performed for the evaluation of collagen and fibronectin respectively.</p><p><b>RESULTS</b>hAEC showed a cobblestone-like growth. After implanted into the injured vocal folds, hAEC could survive in vocal fold lamina propria for 2 months. The immunofluorescence analysis showed the evidence of hAEC differentiation into muscle cells as well as secretion the ECM protein. Three months postoperatively, the density of collagen was higher in the injured untreated control folds than that in the injured vocal folds injected with hAEC and the untreated controls. Besides, the content of fibronectin in the injured untreated control group was significantly increased.</p><p><b>CONCLUSIONS</b>hAEC survived in the vocal folds lamina propria, and had the potentiality to differentiate into vocal folds tissue and secret some ECM components. The histological improvement caused by the injected cells demonstrate that hAEC had the ability to promote the repairment and regeneration of injured vocal folds.</p>

Biological characteristics of rat neural stem cells transfected with human brain-derived neurotrophic factor and green fluorescent protein genes / 中华神经医学杂志

Objective To explore the expression of human brain-derived neurotrophic factor (hBDNF) and green fluorescent protein (GFP) in hBDNF-GFP gene-transfected rat neural stem cells (NSCs) and the changes in the biological characteristics of the transfected cells. Methods NSCs were transfected with a lentiviral vector carrying hBDNF and GFP genes (hBDNF-GFP-NSCs) or GFP gene only (GFP-NSCs), with normal NSCs as the control. The expression levels of hBDNF mRNA and hBDNF protein in all the 3 groups were detected by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot, respectively. Enzyme-linked immunosorbent assay (ELISA) was performed to detect hBDNF level in the cell culture medium before and after hBDNF-GFP gene transfection. Dorsal root ganglion (DRG) neurons and NSCs were cultured with the supernatants of the transfected NSCs and normal NSCs, and the growth status of the DRG neurons was observed and the proportion of NSCs differentiating into neurons determined. Results Compared with GFP-NSCs and normal NSCs, hBDNF-GFP-NSCs showed obvious hBDNF overexpression at both rnRNA and protein levels 7 days after the transfection, hBDNF content in the supematant of hBDNF-GFP-NSCs culture increased significantly with time and peaked 5 days after the transfecfion (P<0.05). Four days after culture in hBDNF-GFP-NSCs supernatant, the DRG neurons and adherent NSCs extended cells processes, and the ratio of the NSCs differentiating into neurons was higher in cells cultured in hBDNF-GFP-NSCs supematant than in those culture in GFP-NSCs and normal NSCs supematants. Conclusion Lentivitus can be used as the vector for hBDNF and GFP gene transfection into NSCs, and hBDNF-GFP gene-transfected NSCs maintain the basic characteristics of NSCs and are capable of stable expression and secretion of hBDNF and GFP.