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)
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 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.
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 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 level of cell adhesion molecule sialyl-LeX expression in colorectal carcinoma and its relation with carcinogenesis, differentiation, metastasis and prognosis. Methods Sialyl -LeX expression and its optical density in colorectal carcinoma (n=90) and remote normal mucosa (n=30) were quantitatively studied with microwave-LSAB immunohistochemical method combined with image analysis technique. Fifty-three patients were followed up. Results The weaker staining in remote normal colorectal mucosa was observed in very limited parts of some deep crypts. Positive rate of sialyl-LeX expression was only 16.7%(5/30). The positive expression of sialyl-LeX was observed in 83 of 90 patients with colorectal carcinoma(92.2%). The apical cytoplasma of cancer tubules, the luminal contents, and the cytoplasma of the cancer cells were bly stained. The mean integral optical density of sialyl-LeX positive cell in poorly differentiated adenocarcinoma was significantly higher than that in highly differentiated and mucinous ones (Plt;0.01). It was markedly higher in patients with positive lymphatic nodes than that in negative ones (Plt;0.01). With followed-up for longer than 5 years, it was much lower in the alive cases than that in the dead (Plt;0.01). Conclusion These findings indicate that changes of sialyl-LeX expression and its optical density is related to carcinogenesis, differentiation, invasion and metastasis of colorectal carcinoma. It may be a good predicter for the prognosis of patients with colorectal carcinoma.
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.