【Abstract】Objective To investigate the correlation between the expression of fibronectin (FN) in extracellular matrix (ECM) and angiogenesis of gastric carcinoma.Methods The expressions of FN and vascular endothelial growth factor (VEGF) in 20 specimens of normal gastric tissue (normal group) and 80 specimens of gastric carcinoma tissue(gastric carcinoma group) were detected by EnVisonTM immunohistochemical technique. Tumor microvessel densit y (MVD) was evaluated by using antiCD34 antibody as an endothelial marker by the same technique as well. Results The immune complex of FN stained in brown were distributed around glands and in connective tissue of gastric specimens. In normal group, the staining of FN formed intact linear structure at basement membrane and presented regular striae form in connective tissue. In gastric carcinoma group, the integrity of linear structure of FN staining at basement membrane were destroyed to different extent and the staining of FN in connective tissue were changed deeper and distributed irregularly. The expression of VEGF and the value of MVD in the gastric carcinoma group was higher than those in normal group’s(P＜0.01, P＜0.01, respectively).This study indicated, that in gastric carcinoma group, the degree of FN expression in connective tissue had statistically positive correlations with the degree of VEGF expression and MVD value(P＜0.01, P＜0.05, respectively). Whereas the destruction extent of linear structure of FN staining at basement membrane showed no correlation with VEGF expression and MVD value(Pgt;0.05, Pgt;0.05, respectively).Conclusion The higher expression of FN in connective tissue of gastric carcinoma may well play a critical role in its process of angiogenesis and vasculogenesis. There may be an cooperative interactions between FN and VEGF in the process of angiogenesis and vasculogenesis of gastric carcinoma.
Objective To explore the regulator factor of osteogenes is induced by the fibroblast in vitro so as to provide enough seeding cells for the bon e tissue engineering. Methods The fibroblasts were isolated and purified from granu lation of New Zealand rabbits, and they were incubated in the media offibronectin (FN) 10, 20, 40, 60 and 80 μg/ml, respectively, in the experimenta l grou ps 1- 5，but there was no FN in the control group. The markers for osteogenic features were investigated by fibroblast morphogenesis,calcium nodules formationratios,labeling of tetracycline fluorescence, labeling of 3H-TdR, determination of o steocaline, and labeling of 3H-proline within 2 weeks. Results The morphologic al changes of the fibroblasts were manifested as transference from a long spindle to a round or multiple form, shifted nucleus increased in number, confluenced and formed multilayered structure. There was a piling-up of calcium crystals that were gradually merged into foggy substances. The foggy substances increased and formed nodules. The calcium nodules formation ratios were as follows: 15.35％± 3.45％in the control group, and 53.73％± 9.49％, 75.21％± 9.80％, 98.34％± 15.2 0％, 61.83％± 10.04％, and 45.11％± 8.70％ in the experimental groups 1.5 ,respectively. There was a significant difference between the control group and the 5 experimental groups at 14 days (Plt;0.05), and a significant differenc e be tween the experimental group 3 and the other experimental groups at 14 days (Plt;0.05). The histochemical study on the nodules with the specific labeling of tet racycline fluorescence indicated that the nodules were composed of new bones. Conclusion Fibronectin can stimulate the fibroblast to prolifer ate, secrete osteocaline, and synthesize collagen fibrils. Fibronectin, in an optimal dose of 40 -60 μg/ml, is capable of inducing the fibroblast to form the bone.
OBJECTIVE To determine the characteristics and regularity of fibronectin mRNA expression in diabetic ulcers, and to investigate the relationship between the changes of fibronectin mRNA expression and pathogenesis of diabetic ulcer. METHODS Biopsies were removed from the margins of diabetic foot ulcers, included surrounding skin as experimental group, and the biopsies from normal skin of the same patients as control group. The mRNA expression of fibronectin was measured by quantitative RT-PCR technique. RESULTS The mRNA expression of fibronectin could be detected in both normal skin and diabetic foot ulcers, but the level of expression in diabetic ulcers was lower than that of normal skin. CONCLUSION The level of mRNA expression of fibronectin in diabetic ulcers is decreased, which suggest that the down-regulation of transcription may be one of the mechanisms of chronic impaired ulcers.
Objective To study the expression of the fibronectin (FN) and beta;1 integrin (beta;1) in epiretinal membranes(ERM) of eyes with proliferative vitreoretinopathy(PVR). Methods wenty epiretinal membranes were obtained from eyes undergone vitrectomy for retinal detachment complicated with PVR and observed by immunohistochemical methods. Results Overexpression of FN and beta;1 were observed in 18 and 16 membranes respectively． Conclusion The synergism of FN and beta;1 in their action mignt be one of the important roles in the development of PVR. (Chin J Ocul Fundus Dis, 2001,17:119-121)
ObjectiveTo explore the relationship between the expressions of fibronectin (FN) and phosphatase and tensin homology deleted on ehromosome ten (PTEN) in hepatocellular carcinoma (HCC) tissues and the clinical pathological features. MethodsThe expressions of FN and PTEN were detected by using Western blot and immunohistochemistry respectively in 83 HCC tissues and para-carcinoma tissues, 47 hepatic cirrhosis tissues and 11 normal hepatic tissues. The correlations between the expressions of FN and PTEN and the clinicopathologic features of HCC patients were analyzed. ResultsThe positive expression rate of FN protein in HCC tissues was significantly higher than those in para-carcinoma tissue, normal hepatic tissue, and liver cirrhosis tissues (P<0.05); meanwhile the expression of PTEN was opposite (P<0.05). The positive expression rate of FN protein in para-carcinoma tissues was also obviously higher than that liver cirrhosis tissues and normal hepatic tissues (P<0.05), meanwhile the expression of PTEN was opposite (P<0.05). The positive expression rate of FN protein was higher in HCC tissues with cancer embolus, lymphatic metastasis, positive AFP, and multiple tumor (P<0.05), but there were no statistically significant differences in FN protein expression, gender, age, HBsAg, degree of tumor differentiation, and size of tumor (P>0.05). The positive expression rate of PTEN was lower in HCC tissues with high-medium differentiation, cancer embolus, positive AFP, lymphatic metastasis, and tumor diameter ≥2 cm (P<0.05), there were no statistically significant differences in PTEN expression, gender, age, HBsAg, and the number of tumor (P>0.05). ConclusionsThe abnormal expressions of FN and PTEN in HCC tissues which may play a role in promoting or inhibiting occurrence, development, invasion, and metastasis of HCC. The abnormal expressions of both can be used as molecular biological markers for the malignant degree, invasion, and metastasis of HCC.
ObjectiveTo investigate the feasibil ity of the domestic porous tantalum as scaffold material of bone tissue engineering by observing the expressions of osteogenesis related factors of MG63 cells co-cultured with domestic porous tantalum. MethodsMG63 cells were cultured with porous tantalum scaffolds (group A), with porous tantalum leaching solution (group B), and with MEM as control group (group C). The cell adhesion of group A was observed on the scaffolds at 3, 5, and 7 days after culture by scanning electron microscopy (SEM); immunohistochemistry and Western blot methods were used to detect the expressions of Runt-related transcri ption factor 2 (Runx-2), osteocalcin (OC), and fibronectin (FN). ResultsAt 3 days after culture, the cells of group A adhered the surface and pore of the porous tantalum scaffolds, with sparse cell arrangement and less protuberances; at 5 days after culture, adjacent cells connected to be a flat each other, which covered the surface and pore of the scaffold; at 7 days after culture, cells secreted plenty of extracellular matrix, covering most of the material surface. The expressions of Runx-2, OC, and FN were positive in 3 groups; darker staining of the cytoplasm was observed in group A, the expressions were significantly higher in group A than in other 2 groups. The results of immunohistochemistry and Western blot showed that the expressions of Runx-2 and OC were significantly increased in group A when compared with those in groups B and C (P < 0.05), but no significant difference was found between groups B and C (P > 0.05). The expression of FN had no significant difference among 3 groups (P > 0.05). ConclusionDomestic porous tantalum could promote MG63 cells adhesion and growth, and may promote the expressions of Runx-2 and OC, so it can be used as a scaffold material of bone tissue engineering.
ObjectiveTo isolate and culture cartilage derived stem cells from different subtypes of cartilages, and to identify their characteristics. MethodsCartilage derived stem cells were isolated from different subtypes of cartilages (auricle cartilage, articular cartilage, and intervertebral cartilage) by using adhesive method of fibronectin. The expressions of positive surface markers (CD29 and CD90) and negative surface markers (CD34 and CD45) in cartilage derived stem cells were detected via flow cytometry. The single cell colony-forming efficiency of cartilage derived stem cells was determined by clonal formation unit test; the multipotent differentiation capacity was identified by chondrogensis, osteogenesis, and adipogenesis induction. RT-PCR was used to test the expression of osteogenic, chondrogenic, and adipogenic genes; and bone marrow mesenchymal stem cells (BMSCs) served as control. ResultsThree cell populations were successfully isolated from different subtypes of cartilages, which could express CD29 and CD 90 highly, but did not express CD34 and CD45. After 2 weeks of culture, single cartilage derived stem cell could form single cell colony. In addition, cartilage derived stem cells had high chondrogenesis, osteogenesis, and adipogenesis potentials. After osteogenic induction, the expressions of collagen type Ⅰ and collagen type X in articular and intervertebral cartilage stem cells were significantly higher than those in BMSCs (P<0.05), while there was no significant difference between auricular cartilage stem cells and BMSCs (P>0.05). The expressions of Aggrecan and collagen type Ⅱ in cartilage derived stem cells after chondrogenic induction were significantly higher than those in BMSCs (P<0.05). While the ability of adipogenic differentiation was lower than that in BMSCs, but no significant difference was found (P>0.05). ConclusionCartilage derived stem cells in different subtypes of cartilages possess typical characteristics of stem cells.
ObjectiveTo construct a prokaryotic expression strain of Staphylococcus aureus fibronectin binding protein A (FnBPA) r10-11 truncated fusion protein, and explore the immunogenicity of FnBPAr10-11. MethodsPloymerase chain reaction (PCR) amplification was carried out from the whole genome sequence of Staphylococcus aureus Newman strain by recombinant PCR technique. The amplified product was purified and transformed into Escherichia coli DH5α for cloning. The recombinant plasmid was extracted and identified by double enzyme digestion. The recovered fragment was ligated into the pET-32a plasmid and transformed into Escherichia coli BL21 (DE3) for prokaryotic expression. The FnBPAr10-11 was purified by HIS protein purification column, identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and used to immunize mice, and the mice were divided into phosphate buffered saline (PBS) group, FnBPA group, and FnBPAr10-11 group. The serum levels of immunoglobulin G (IgG) and cytokines, and the immune protection rate of the mice were detected. ResultsSDS-PAGE result showed that the relative molecular mass of the protein was about 33.1×103. The titers of IgG antibody in FnBPAr10-11 group and FnBPA group reached 1∶128 000, and were significantly different compared with PBS group (P<0.05). The cytokine level in FnBPAr10-11 group was not significantly different compared with that in FnBPA group, and they were extremely significant (P<0.01) compared with that in PBS group. The immuno-protective effect of the FnBPAr10-11 group was over 50%. ConclusionsThe prokaryotic expression strain of Staphylococcus aureu FnBPAr10-11 truncated fusion protein was successfully constructed. The truncated protein has good immunogenicity.