OBJECTIVE To investigate the adhesive interactions of cells with materials and the effects of material properties on cell adhesion in tissue engineering. METHODS By looking up the recent literatures dealt with adhesive interactions of cells with materials and reviewing previous work on the adhesion of tissue-derived cells to materials. RESULTS The adhesion characteristics of cells to materials not only depend on the nature of materials, including bulk and surface properties, surface modification, surface morphology, net charge, porosity and degradation rate, but also on the expression of cell surface molecules and their interaction with the material. CONCLUSION The quantitative measure and biophysical mechanisms of cell adhesion to materials might be very important in tissue engineering.
OBJECTIVE: To investigate the influence of basic fibroblast growth factor (bFGF) on adhesion characteristics of osteoblasts, aimed at the important problem in bone tissue engineering of how to promote the adherence of osteoblasts to extracellular matrix materials. METHODS: 5 ng/ml, 10 ng/ml, 50 ng/ml, 100 ng/ml, 200 ng/ml bFGF were used to induce bone marrow stromal-derived osteoblasts of rabbit for 24 hours before incubation, and the common culture medium as the control. The attached cells were calculated with stereology method at 0.5 hour, 1st hour, 2nd hour, 4th hour, 8th hour after seeding. RESULTS: The number of attached cells was significant higher in the experimental group when induced by 10 ng/ml bFGF than that in the control group (P lt; 0.01); the number did not increase with the increase of bFGF concentration and there was no significant difference between the experimental group induced by 100 ng/ml bFGF and control group, and the number was even obviously lower in the experimental group when induced by 200 ng/ml than the control group (P lt; 0.01). CONCLUSION: bFGF can influence the adhesion characteristics of osteoblasts, 10 ng/ml bFGF can promote the adherence of osteoblasts to matrix materials, but 200 ng/ml bFGF may inhibit cell adhesion.
Objective To observe whether Cyclo-RGDfK (Arg-Gly-Asp-D-Phe-Lys) could enhance the adhesion of myofibroblast to decellularized scaffolds and upregulate the expression of Integrin αVβ3 gene. Methods Myofibroblast from the rat thoracic aorta was acquired by primary cell culture. The expression of Vimentin and α-smooth muscle actin(α-SMA) has been detected by immunoflurescent labeling. Decellularized valves have been randomly divided into three groups (each n=7). Group A (blank control): valves do not receive any pretreatment; Group B: valves reacted with linking agent NEthylN(3dimethylaminopropyl)carbodiimide hydrochloride (EDC) for 36 hours before being seeded; Experimental group: Cyclo-RGD peptide has been covalently immobilized onto the surface of scaffolds by linking agent EDC. The fifth generation of myofibroblast has been planted on the scaffolds of each group. The adhesion of myofibroblast to the scaffolds was evaluated by HE staining and electron scanning microscope. The expression of Integrin αVβ3 was quantified by halfquantitative reverse transcriptionpolymerase china reaction (RT-PCR). Results We can see that myofibroblast has exhibited b positive staining for Vimentin and α-SMA. Besides, it has been shown that the expression of Integrin αVβ3 was much higher in the experimental group than that of the group A and group B(Plt;0.05). There was no statistically difference in group A and group B (P=0.900). Conclusion RGD pretreatment does enhance the adhesive efficiency of seeding cells to the scaffolds and this effect may be related to the upregulation of Integrin αVβ3.
ObjectiveTo summarize the progress of p120-catenin (p120ctn)——a new member of catenin family in tumor research. MethodsDemestic and international published literatures related to p120ctn in recent years were collected and reviewed. Results① p120ctn was involved in formation of cadherincatenin complex, participated in cell growth, proliferation, and adheren junctions. ② p120ctn regulated Rho GTP activity and promoted cell motility. ③ p120ctn was involved in the regulation of gene transcription through binding with the nuclear transcription factor Kaiso. ④ p120ctn was involved in angiogenesis process induced by vascular endothelial growth factor. ⑤ p120ctn was involved in inflammation, cell malignant transformation, and tumor invasion and metastasis. ConclusionsAs a new member of catenin family, p120ctn participates in a variety of biological processes relying on its cellular localization. It will be facilitated to judge the genesis and progression of tumor from the abnormal alteration of p120ctn according to understanding the biological function and mechanism of p120ctn in the molecular level, a new pathway in the prevention and treatment of cancer is provided.
Objective To study the relationship between expression of nm23, CD44 in gastric carcinoma and lymph-node metastasis and prognosis. Methods Expression of nm 23, CD44H and CD44V6 in 105 cases of gastric carcinoma were assayed by immunohistochemistry. Among them, 59 cases were followed up. Results The incidences of nm23, CD44H and CD44V6 protein positivity in gastric carcinoma were 44.8%, 54.3% and 48.6% respectively. The positive expression of nm23, CD44V6 protein in human gastric carcinoma tissues was related to the differentiation, depth of invasion, TNM stage and prognosis (Ｐ＜0.05), but expression of CD44H was not correlated with other clinicopathologic indices. The reactivity to these three antibodies were correlate with metastasis of lymph nodes (Ｐ＜0.01 for CD44V6 and Ｐ＜0.05 for nm23, CD44H). Conclusion Expression of the standard form of CD44 (CD44H) might be useful in observing the progression of the disease, wile CD44V6 and nm23 hold promise as a prognostic indicator.
Objective To investigate the expression of nuclear factor (NF)-κB and intercellular adhesion molecule (ICAM)-1 in rat′s retina injured by ischemia-reperfusion, and the effect of pyrrolidine dithiocarbamate (PDTC) on the expression of NF-κB and ICAM-1. Method The model of retinal ischemia-reperfusion was set up in 60 SD rats, which were divided into two groups with 30 rats in each: ischemia-reperfusion group and ischemia-reperfussion with injection of PDTC group. The left cephalic artery of each rat was ligated, and the right side was the control. Every group was subdivided into group 1 hour, 6, 12, 24, 48, and 72 hours after ischemia-reperfusion injury, and with 5 rats in each group. mRNA of NF-κB and ICAM-1 mRNA was measured by in situ hybridization (ISH) method in rat′s retina. Every rat underwent electroretinography (ERG) at the corresponding time before executed by neck breaking. Results In ischemia-reperfusion group, expression of NF-κB and ICAM-1 was detected at the 6th hour after ischemia-reperfusion, reached the highest level at the 24th hour, and weakened gradually later. In ischemia-reperfusion with injection of PDTC group, expression of NF-κB and ICAM-1 was detected at the 12th hour after ischemia-reperfusion, and reached the highest level at the 24th hour but lower than that in ischemia-reperfusion group. No expression of NF-κB and ICAM-1 was found in the control group. The relative recovery rate of ERG a and b wave amplitude in ischemia-reperfusion groups was lower than that in ischemia-reperfusion with injection of PDTC group at every stage(P＜0.01 ). The lowest relative recovery rate of ERG a and b wave amplitude in different stages in both of the 2 groups was at the 24th hour(P＜0.01). Conclusions NF-κB and ICAM-1 may play an important role in retinal ischemia-reperfusion injury, as the inhibitor of NF-κB, PDTC may relieve the retinal ischemia-reperfusion injury. (Chin J Ocul Fundus Dis，2004，20：175-178)
Objective To summarize the latest developments in silk protein fiber as biomaterials and their applications in tissue engineering. Methods Recent original literature on silk protein fiber as biomaterials were reviewed, illustrating the properties of silk protein fiber biomaterials. Results The silk protein fiber has the same functions of supporting the cell adhesion, differentiation and growth as native collagen, and is renewed as novel biomaterials with good biocompatibility, unique mechanical properties and is degradable over a longer time. Conclusion Silk protein-fiber can be used as asuitable matrix for three dimensional cell culture in tissue engineering. It has a great potential applications in other fields.
Objective To review recent studies in molecular biology of gastric cancer. Methods Relevant references were reviewed. Results The development and progression of gastric cancer were correlated with oncogenes, growth factors, cyclins, tumor suppressor genes, cell adhesion molecules and unstability of genes.Conclusion Gastric cancer is related to much mutation of genes.
To study the relationship between the expression and contents of cell adhesion molecule CD15 and differentiation and lymph nodes metastasis of breast carcinomas, CD15 expression and its contents in 94 cases of breast carcinomas and or cases of normal breast tissue were evaluated by microwave-SP immunohistochemical chenique combined with image analysis. CD15 immunoreactivity in normal breast tissue was mainly localised at the border of gland, but in breast cancer tissues it was mainly localised in the membrane and cytoplasm. Positive rate of CD15 and its average optic density in breast carcinomas were significantly higher than those in normal breast tissue (Ｐ＜0.05 and Ｐ＜0.001, respectively). The worse tumors differentiated and the earlier lymph nodes metastasized, the higher CD15 expressed and its optic density was measured (Ｐ＜0.05 and Ｐ＜0.001, respectively). These results suggest that CD15 expression and its contents might be a useful indicator to evaluate the malignancy and biological features, and could be considered as a good prognostic predictor for breast carcinomas.
Objective To investigate the effect of interleukin-10 （IL-10） gene transfer on expression of CD44, selectin-E, lymphocyte function associated antigen-1 （LFA-1）, vascular cell adhesion molecule-1 （VCAM-1） in mice heart transplantation rejection. Methods Model of mice cervical heterotopic heart transplantation was set up, 96 mice were divided into three groups with random number table, control group： heart transplantation between C57 mice; transplant group： heart from BALB/C mice transplant to C57 mice; IL-10 group： IL-10 was transfected on BALB/C mice isolated heart for 1 hour, then transplanted to C57 mice. The messenger ribonucleic acid （mRNA） level expression of CD44 ,selectin-E ,LFA-1 ,VCAM-1 and IL-10 were measured by reverse transcription-polymerase chain reaction （RT-PCR） at the 5th day after transplantation. Results The mRNA level expression of CD44, selectin-E ,LFA-1 ,VCAM-1 in transplant group were significantly increased than those in control group （P〈0.01）. The mRNA level expression of CD44, selectin-E, LFA-1 ,VCAM-1 in IL-10 group were significantly decreased than those in transplant group （P〈0.01）. Conclusion IL-10 gene transfer is able to decrease the expression of CD44, selectin-E,LFA-1 ,VCAM-1 and suppress the heart transplantation rejection in mice.