OBJECTIVE This paper was to study the biological characteristics of the transformed human embryonic tendon cells, the relation between cell growth and culture conditions, and to compare these features with that of human embryonic tendon cells. METHODS The pts A58H plasmid had successfully used to transform a tendon cell line from human embryo in our past work. The human embryonic tendon cells and the transformed human embryonic tendon cells were cultured in vitro. In different culture conditions, the growth curve were drawn respectively. Population dependence and proliferation capability of the cells were investigated through plate cloning test and soft agar culture. The collagen secreted by cells was identified by immunohistochemical method. RESULTS In routine culture condition, the growth properties of the human embryonic tendon cell and transformed cells were almost identical. The growth properties of the transformed cells were not changed when the cells were frozen storage. There were changes of growth characteristics of the transformed cells when the culture temperature was changed. The transformed cells could subcultured continually and permanently. The proliferation capability of the transformed cells were ber than that of the human embryonic tendon cells. Moreover, the growth of the transformed cells was serum-dependent, and the phenomenon of contact inhibition was observed. The transformed cells were not able to grow on soft agar culture. They had the capacity of secreting collagen type I. CONCLUSION The transformed human embryonic tendon cells could be subcultured continually and permanently, and their growth could be controlled by changing their culture conditions and they had no malignant tendency in biological characteristics. They could be taken as an ideal experimental material for tendon engineering.
Objective To explore the relationship between Beclin-1 and the development of pancreatic ductal adenocarcinoma (PDAC). Methods ① Twenty-five PDAC specimens and 20 matched adjacent normal pancreatic tissues were obtained after radical surgery between April 2009 and November 2009 in West China Hospital of Sichuan University. Beclin-1 mRNA and protein expressions were examined by using real-time PCR and immunohistochemistry, respectively. Correlations between expressions of Beclin-1 protein with clinical data of PDAC patients were evaluated. ② PDAC cells were divided into 2 groups, cells of transfection group were transfected with PLenO-WPI-Beclin-1 vector, and cells of non-transfection group didn’t transfected with PLenO-WPI-Beclin-1 vector. Expressions levels of Beclin-1 mRNA in the 2 groups were detected by real-time PCR at 24 hours and 48 hours after transfection. ③ PDAC cells were divided into 3 groups, cells of transfection group were transfected with PLenO-WPI-Beclin-1 vector, cells of empty vector group transfected with PLenO-WPI, cells of blank control group didn’t accepted any vector. OD value was detected by MTT once a day during 1–7 days after transfection. Results ① Expression levels of Beclin-1 mRNA and its protein were significantly lower in PDAC tissue than those of adjacent normal pancreatic tissues (P<0.05). Increased Beclin-1 expression was associated with early TNM stage of Ⅰ and Ⅱ(P<0.05) and negative distant metastasis (P=0.011). ② At the same time point of 24 hours and 48 hours after transfection, the expression levels of Beclin-1 mRNA were higher in transfection group than those of non-transfection group (P<0.05). ③ MTT assay showed that PANC-1 cell proliferation ability was lower in the transfection group compared to the blank control group and empty vector groups in vitro on day 4–7 after transfection (P<0.05), but there was no significant in the cell proliferation ability among the 3 groups on day 1, 2, and 3 (P>0.05). Conclusions Down regulation of Beclin-1 and autophagy inhibition play an important role in the tumorigenesis and development of PDAC. Activating autophagy via overexpression of Beclin-1 may be a potential treatment for some PDACs and warrants further investigation.
ObjectiveTo explore a simple, efficient method for primary culture in vascular smooth muscle cells of diabetic rat, to establish a long-term stable diabetic vascular smooth muscle cell model in vitro, and lay the foundation for the study of diabetes chronic vascular lesions. MethodsTwenty diabetic Wister rats models were self-made by using streptozotocin intraperitoneal injection plus high fat and sugar feeding, the vascular smooth muscle cells in vitro was cultured by a modified enzymatic digestion. ResultsThe diabetic rat models were successfully established, the vascular smooth muscle cells cultured in vitro by modified enzyme digestion grew fast, the cell survival was 96%, it could meet the requirements for cell experiment in vitro. ConclusionComparing with the traditional method, the modified enzymatic digestion method is simple, economic, high survival rate.
Objective To explore the effects of mechanical stretch with variant frequencies on the alignment and differentiation of the multilayer myotubes cultured in vitro, and to select the optimized cultural condition of regenerative skeletal muscle tissue with stress loading cultured in vitro. Methods C2C12 myoblasts cultured in vitro in the groove casts of Sylgard 184 were induced into the multilayer myotubes. Meanwhile the myoblasts were treated with various mechanical stretch withcells tensile instrument, at the amplitude of 10% and the frequency of 0 (group A), 0.25 (group B), 0.50 (group C), and 1.00 Hz (group D) for 1 hour, 3 times a day. The myotubes morphology was observed by inverted phase contrast microscope at 5, 7, and 10 days after continuous mechanical stretch. And the expressions of mRNA for myogenic differentiation antigen (MyoD), Myogenin, Desmin, and myosin heavy chain (MyHC) were detected by RT-PCR and real-time fluorescent quantitative PCR (QRT-PCR), respectively. Results The mechanical stretch could promote the al igned fusion and increase the number of myotubes. Indeed the multilayer myotubes arranged more closely in group B at 7 days. At the same group, as the time went on, the mRNA expressions of MyoD gradually decl ined in each group. There were significant differences in mRNA expressions of MyoD between 5 days and 7, 10 days (P lt; 0.05). The mRNA expressions of Myogenin, Desmin, and MyHC were highest at 7 days. There were significant differences between different time points (P lt; 0.05), except the mRNA expression of Desmin of group B between 7 and 10 days (P gt; 0.05). At the same time, with the increase of frequency, the highest mRNA expressions of MyoD, Myogenin, Desmin, and MyHC were in group B. There were significant differences at the same time between group B and the other groups (P lt; 0.05), except mRNA expression of Desmin at 5 days between groups B and C, and mRNA expression of MyHC at 10 days between groups A and B (P gt; 0.05). Conclusion Low frequency (0.25 Hz) and suitable time (7 days) periodic mechanical stretch is beneficial to the differentiation of the multilayer myotubes cultured in the groove casts of Sylgard 184, but as the stretch time goes on the aging of myotubes will be accelerated.
Objective The biological effects of fibroblast growth factor (FGF) may be different under different intensities and durations. To investigate the impact of sustained increasing FGF signal upon the development of epiphyseal plate. Methods Epiphyseal plates cultured in vitro were obtained from embryonic C57BL/6J mice, and were divided into control group (0.1% DMSO), basic FGF (bFGF) group (100 μg/L bFGF and 0.1% DMSO), and PD98059 group (100 μg/L bFGF and 50 μmol/L PD98059 with 0.1% DMSO). The total length (TL) and ossified tissue length (OSL) of the cultured bones weremeasured with Calcein staining 6 days after culture. The expressions of Indian hedgehog (Ihh), collagen type II (Col II), and Col X genes were detected by real-time fluorescent quantative PCR 7 days after culture. Results The embryonic bones cultured in vitro continued growth. At 6 days after culture, there was no significant difference in increased percentage of TL between bFGF group and control group (P gt; 0.05), the increased percentage of OSL in bFGF group was significantly less than that in control group (P lt; 0.05). There was no significant difference in the increased percentage of TL and OSL between PD98059 group and control group (P gt; 0.05), but they were significantly higher than those of bFGF group (P lt; 0.05). At 7 days after culture, the gene expressions of Ihh, Col II, and Col X in bFGF group significantly decreased when compared with those in control group (P lt; 0.05). There was no significant difference in the gene expressions of Col II and Col X between PD98059 group and control group (P gt; 0.05), but the gene expressions were significantly higher than those of bFGF group (P lt; 0.05); the expression of Ihh in PD98059 group was significantly higher than that in control group and bFGF group (P lt; 0.05). Conclusion Sustained increasing FGF signal may affect the Col II and Col X expressions by down-regulating Ihh, which may lead to the development retardation of epiphyseal plate cultured in vitro. The external signal regulated kinase pathway may play an important role in the process.
Objective To understand the effect of estradiol in different concentrations on proliferation of diverse mammary primary cells in vitro. Methods The primary cells of cancer tissue, the adjacent tissue to tumors and normal mammary tissue from patiens with breast cancer were obtained using collagenase digesting method. All the tissue samples were cultivated in vitro, and were given estradiol in different concentrations. The effect of estradiol on the proliferation of those primary cells was measured by MTT. Results Estradiol remarkedly promoted the proliferation of primary cells of cancer tissue and peritumor tissue in vitro, whose ER expression were positive. Whereas, the promotion effect of estradiol on the proliferation of normal mammary primary cells was relatively weak, and there was no correlation between the promotion effect with the expression of ER in cancer tissue. Conclusion The risks of occurrence and relapse of breast cancer would increase significantly when the concentration of estradiol is no less than 103 pmol/L in vivo.
Objective To study the differenation of adult marrow mesenchymal stem cells(MSCs) into vascular endothelial cells in vitro and to explore inducing conditions. Methods MSCs were isolated from adult marrow mononuclear cells by attaching growth. MSCs were divided into 4 groups to induce: the cells seeded at a density of 5×103/cm2 in 2% and 15% FCS LDMEM respectively (group1 and group 2)， at a density of 5×104/cm2 in 2% and 15% FCS LDMEM respectively (group 3 and group 4); vascular endothelial growth factor(VEGF) supplemented with Bovine pituitary extract was used to induce the cell differentiation. The differentiated cells were identified by measuring surfacemarks (CD34, VEGFR2, CD31 and vWF ) on the 14th day and 21st day and performed angiogenesis in vitroon the 21st day.The cell proliferation index（PI）of different inducing conditions were measured. Results After induced in VEGF supplemented with Bovine pituitary extract, the cells of group 3 expressed the surface marks CD34, VEGFR-2, CD31 and vWF on the 14th day, the positive rates were 8.5%, 12.0%, 40.0% and 30.0% respectively, and on the 21st day the positive ratesof CD34 and VEGFR2 increased to 15.5％ and 20.0％, while the other groups did not express these marks; the induced cells of group 3 showed low proliferating state(PI was 10.4%) and formed capillary-like structure in semisolid medium. Conclusion Adult MSCs can differentiate into vascular endothelial cellsafter induced by VEGF and Bovine pituitary extract at high cell densities and low proliferatingconditions，suggesting that adult MSCs will be ideal seed cells forthe therapeutic neovascularization and tissue engineering.
In vitro experimental test for mechanical properties of a vascular stent is a main method to evaluate its effectiveness and safety, which is of great significance to the clinical applications. In this study, a comparative study of planar, V-groove and radial compression methods for the radial support property test were performed, and the effects of compression rate and circumferential position on the test results were conducted. Based on the three-point bending method, the influences of compression rate and circumferential position on flexibility were also explored. And then a best test proposal was selected to evaluate the radial support property and flexibility of the three self-designed stents and the comparative biodegradable vascular stent (BVS) (BVS1.1, Abbott Vascular, USA) with different outside diameters of 1.4 mm, 1.7 mm and 2.4 mm. The results show that the developing trends of the compression load with the compression displacement measured by the three radial support property test methods are the same, but normalized radial force values are quite different. The planar compression method is more suitable for comparing the radial support properties of stents with different diameters and structures. Compression rate has no obvious effect on the testing results of both the radial support property and flexibility. Compression circumferential position has a great impact on testing radial support property with the planar or V-groove compression methods and testing flexibility with three-point bending method. The radial support properties of all the three self-designed stents are improved at a certain degree compared to that of the BVS stent. The study has better guide significance and reference value for testing mechanical properties of vascular stents.
Following the peritendon was removed by means of microsurgical technique, the tenocyte was isolated from the human embryonic tendons by digesting it with trypsin and collagenase. These cells were all stored in frozen condition until they were cultured by F12 culture fluid added with 20% FBS to the 15th generation.These cells were able to grow adhering to the wall and stop growing with contact inhibition. The time of cellsgroup duplication was 4 days, which was similar to the peak time of its mitosis. The number of its chromosome group 2n=46 was 87.5-91.0%. The optimal conditions for tendon cell culture in vitro were investigated, and it was found that after they were reaminated and subcultured the frozen storage didn’t influence their growth, morphology, genetic characteristics. In our research we detected the content generation cells and found the cultured human embryonic tenocyte had same ability never changed with the cells subcultured. We also disscussed the future of tenocyte-a biomaterial in the field of artificial implant.