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.
ObjectivesTo investigate the expression of E-selectin of adhesive molecule in microvessels in rats′ retina with diabetic retinopathy (DR) at the early, middle, and late phase.MethodsNinety Sprague Dawley (SD) male rats were randomly divided into normal control group (6, 9, and 12 months subgroups with 10 rats in each subgroup) and streptozotocin (STZ) DR group (6, 9, 12 months subgroups with 20 rats in each subgroup). The DR model was set up by one-off celiac injection with STZ at a dose of 60 mg/kg. The rats were executed according to the different time points, and the eyeballs were removed and the digested stretched preparations of retinal microvessels were made. E-selectin of adhesive molecule in microvessels was revealed by EnVision immunohistochemical staining, and the expression of E-selectin in retinal microvessels and the morphological changes were analyzed and observed by Leica-Q550W computer image analytical equipment. The relativity between degree of impairment of DR and expression of E-selectin was detected.ResultsMorphological changes: hyperplasia of endotheliocytes and decreased pericytes were found in 6month DR group; irregularly arranged retinal capillary networks, obviously thickened basilar membrane, many aggregation and adhesion of leucocytes to capillary walls, large areas of acellular capillaries, and opoptosis of endotheliocytes and pericytes were found in 9-and 12-month DR group. Results of quantitative analysis: there was no expression of E-selectin in normal control group, while expression of E-selectin with different degree in each DR group was found. There was significance difference among DR subgroups (Plt;0.01), and the highest expression was found in 6-and 12-month DR group.ConclusionsThe expression of adhesive molecule in microvessels in rats' retina increases as the disease course of DR extends, and has positive correlation with the degree of impairment of microvessels in DR. (Chin J Ocul Fundus Dis, 2005,21:318-321)
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)
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 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.
Objective To investigate the influence of CO2-insufflation pressure on invasion potential of the colon cancer cells. Methods With an in vitro artificial pneumoperitoneum model, SW1116 human colon cancer cells were exposed to CO2-insufflation of 5 different pressure groups: 6, 9, 12, 15 mm Hg and control group, respectively for 1 h. The invasion capacities of SW1116 cells exposed to CO2-insufflation of 5 different pressure groups were detected by cell adhesion/invasion assay in vitro. Results Immediately following exposure to 15 mm Hg CO2 insufflation, the invasion of SW1116 cells decreased significantly compared to the cells before exposure. At the 0 h time point, the cells exposed to 15 mm Hg were significantly less invasive than those exposed to the other insufflation pressure (P＜0.05), and the cells exposed to 6 mm Hg were more invasive than cells exposed to the other insufflation pressure (P＜0.05). And 72 h after exposed to CO2-insufflation, the differences between the pressure groups were not significant. Conclusion CO2-insufflation induced a temporary change in the invasion capacity of cancer cells in vitro, higher pressure of CO2-insufflation inhibits the invasion potential.
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.
Objective To observe the effect of hypoxia inducible factor-1alpha;（HIF-1alpha;）to the expression of cell surface adhesion molecules CD18 and the adhesion ability of leukocytes and vascular endothelial cells under early stage of diabetic retinopathy condition.Methods The human promyelocytic leukemia cell line HL60 and the rhesus choroid-retina vascular endothelial cell line RF/6A were cultured in RPMI 1640 medium-10% human serum, which was collected from the subjects of early stage of diabetic retinopathy and age-matched healthy control. The cells were cultured in 4 groups as control group (group A), diabetic group (group B), HIF-1 anti-sense oligonucleotides (ASODN) group (group C) and HIF-1 sense oligonucleotides (SODN) group (group D). The percentages of CD18 positive cell in the HL60 cell were measured by flow cytometry and mRNA in the HL60 cell by realtime reverse transcriptionpolymerase chain reaction（RT-PCR）. Results The percentage of CD18 positive cell in the group A, B, C and D was 17.06plusmn;6.01, 42.23plusmn;2.60, 25.33plusmn;3.05 and 32.40plusmn;10.57, respectively, the differences among them were significant (F=36.47,P＜0.001). Compared to the group A,the expression of CD18 mRNA in the group B,C and D was increased about 21.05plusmn;2.07、2.23plusmn;0.96 and 25.07plusmn;2.27 times,respectively, the differences among them were significant (F=180.34, Plt;0.001). The adherent rates of HL60 to RF/6A in group A, B, C and D was 0.06plusmn;0.00,0.09plusmn;0.10,0.05plusmn;0.00 and 0.07plusmn;0.01, respectively,the differences among them were significant（F=13.06，P=0.002）.Conclusion In vitro, HIF-1 could regulate the expression of CD18 by HL60, and the adhesion of HL60 to RF/6A when the cells were exposed to diabetic serum. The effects of human serum weaken with the inhibition of HIF-1 expression.HIF-1 play regulatory role in the expression of CD18 and adhesion of leukocytes and vascular endothelial cells under early stage of diabetic retinopathy condition.
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 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.