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Objective To explore the effect of hepatitis B virus (HBV) X protein (HBx) on autotaxin (ATX) expression and its significance. Methods The recombinant eukaryotic expression vector of HBx ,pcD-NA3.1(+)-HBx,and the recombinant luciferase reporter gene vector of ATX promoter,pGL3-ATX,were con-structed and used to co-transfect HepG2 cells to examine the effect of HBx on the activity of ATX promoter. The sta-ble cell expressing HBx,HepG2.HBx,was constructed,and Western blot(WB)was used to detect the effect of HBx on ATX expression. Results The luciferase activity of pcDNA3.1(+)-HBx and pGL3-ATX group was 1.47 times as that of the empty vector cDNA3.1(+)and pGL3-ATX group(P<0.000). WB detection showed that the expression of ATX protein was increased in HepG2.HBx cells,and 1.75 times as that of HepG2 cells(P<0.05). Conclusion HBx can activate ATX promoter and up-regulate ATX expression ,thus suggests that HBV infection might enhance ATX/LPA signaling.
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Objective To explore the effect of the gene silencing of phosphatidic acid-preferring phospholipase A1 (PA-PLA1) on insulin secretion in mouse insulin-secreting cell line MIN6. Methods The siRNA expression vector of mouse PA-PLA1 gene targeting was constructed using mouse PA-PLA1 mRNA sequence available in GenBank, and MIN6 cells were transfected with the vector. Fluorescence quantitative PCR and Western-blotwere applied to screen efficient RNAi-vector. After transfection with obtained efficient RNAi-vectors for 48 hours, glucose-stimulated insulin secretion experiments were conducted, and the changes of insulin secretion were examined. Results Four siRNA expression vectors of mouse PA-PLA1 gene targeting were confirmed to be successfully constructed by the analyses of enzyme cleavage and sequencing. The results of fluorescence quantitative PCR and Western blot analyses indicated that the siRNA expression vectorpGPU6-PA-PLA1-1885was the most effective RNAi-vector in the four vectors. The expression levels of the PA-PLA1 mRNA and protein of the MIN6 cells transfectedwith pGPU6-PA-PLA1-1885 decreased to 46.3% and 33.9% of that of the control, respectively, and meanwhile the insulin secretion levels of the cells decreased to 65.0% of that of the control (P < 0.05). Conclusion The gene silencing of phosphatidic acid-preferring phospholipase A1 might decrease insulin secretion in MIN6 cells.
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It remains a common problem that the evaluation model of course learning for stu-dents is so simple in the higher education of China. Moreover, the teachers are usually used to evalu-ating student's course learning by summative appraisal and ignore process appraisal, so that the stu-dents are usually lack of learning enthusiasm for self study. Besides, the course learning evaluation of students generally lacks the uniform and detail standard in the country. To resolve these problems, a comprehensive evaluation model of course learning based on the principle of talent evaluation has been practiced and improved since 2007 in some basic medical courses at our university. This model is composed of four parts:the evaluation of mastering basic knowledge, the evaluation of the ability to resolve problems through applied knowledge, the evaluation of practical study and the evaluation of learning initiatives. The model has showed in the practice the characteristics of powerful operability, pluralistic evaluating indicators, combining summative appraisal and process one, reflecting objectively the mastering degree of expertise of students and promoting the self-study of students.
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Molecular biology is the fundamental course of life science,and its experimental teaching is difficult to offer due to its long process and need of expensive equipments.Virtual laboratory platform is an important approach for practice teaching in recent years.This article discussed the advantages and requirements,provided the experience of its applying at our university,and suggested that virtual laboratory platform can play a key role in molecular biology experimental teaching.