Retrovirus-mediated transfer of the fusion gene encoding EGFP-BMP_2 in mesenchymal stem cells

Objective To develop retrovirus-mediated transfer of the fusion gene encoding EGFP-BMP_2 in mesenchymal stem cells.Methods Mesenchymal stem cells from New Zealand white rabbits were transduced with retroviral pLEGFP-BMP_2 vector by the optimized retroviral transduction protocol.Fluorescent microscopy's examination was to evaluate the results of the transduction,flow cytometer's analysis was to evaluate the transduction efficiency and the Fluorescence-activated cell sorting method was to sort the transduced cells.Bioactivity test from C_2C_12K_4 cells was to show the expression and bio-activity of the fusion gene.Results Fluorescent microscopy showed the success of the transduction.By flow cytometer's analysis,the mean efficiency of the transduction with EGFP was(42.8±6.1)% SD.Transduced cells were sorted efficiently by the fluorescence-activated cell sorting method and after sorting,almost of those showed the expression of BMP_2.Fluorescently and strongly bioactivity test for C_2C_12K_4 cells demonstrated that fluorescent materials were located the surface of cells and the activity of luciferase increased compared with the control.Analysis of long-term expression showed there was no difference between 2 week-time point and 3 month-time point of culture post-sorting.Conclusion Mesenchymal stem cells can be transduced efficiently by retrovirus-mediated transfer of the fusion gene encoding EGFP-BMP_2,the highly pure transduced cells are obtained by the fluorescence-activated cell sorting technique,the expressed chimeric protein embraced the double bioactivity of EGFP and BMP_2,and moreover,the expression had not attenuated over time.

Efficient production of transgenic chickens using self-inactive HIV-based lentiviral vectors

We demonstrated the simple and effective production of transgenic chickens, in which the enhanced green fluorescence protein （EGFP） was expressed by using third-generation self-inactive HIV-based lentiviral vectors. In our experiments, lentiviruses were injected into 204 fertilized eggs, from which 30 （15%） chickens were hatched. The exogenous gene was detected in the genomes of 16 out of 30 （53%） chickens. The green fluorescence signal was observed directly in various body parts, and was particularly significant in the testes. The transgenes were also found in the offspring of these chickens. The results indicate that HIV-based lentiviral vectors can be used to generate transgenic birds economically and effectively [ Current Zoology 55 （5）： 383 - 387,2009].

A system for screening agonists targeting β_2-adrenoceptor from Chinese medicinal herbs

In order to develop a model for screening the agonists of human β2-adrenoceptor from Chinese medicinal herbs extracts, we used a cell-based functional assay based on a common G protein-coupled receptor （GPCR） regulation mechanism and destabilized enhanced green fluorescent protein （d2EGFP） reporter gene technique. The positive cell clone was confirmed by real-time polymerase chain reaction （PCR） and imaging analysis. To assess the value of this model, we screened over 2000 high performance liquid chromatography （HPLC）-fractionated samples from the ethanol extracts of Chinese medicinal herbs. Six fractions （isolated from Panax japonicus, Veratrum nigrum, Phellodendron amurense, Fructus Aurantii lmmaturus, Chaenomeles speciosa, and Dictamnus dasycarpus） showed significant effects on active reporter gene expression, three of which （isolated from Phellodendron amurense, Fructus Aurantii lmmaturus, and Chaenomeles speciosa） were selected for further concentration response analysis and the half maximal effective concentration （EC1/2 max） values were 4.2, 2.7, and 4.8 μg/ml, respectively. Therefore, this reporter gene assay was suitable for screening β2-adrenoceptor agonists. The results suggest that the six herbal extracts are the possible agonists of β2-adrenoceptor.