Objective To observe the expression of p53, bcl-2 genes, vascular endothelial cell growth factor（VEGF）, basic fibroblast growth factor（bFGF）, insulin-like growth factor-I （IGF-I）, and the receptors of these factors of retinal vascular endothelial cells (VECs) of 1- to 20-week diabetic rats, and the relationship between the expressions and cell cycle arrest.Methods Retinal sections of diabetic rats induced by alloxan were immunohistochemically stained and observed by light microscopy (LM) and electron microscopy (EM). Dot blotting and Western blotting were used to determine the expression of mRNA, proteins of p53 and bcl-2. Results Under LM, immunohistochemical positive expression of p53 and bcl-2 were found on the vessels of ganglion cell layer and inner nuclear layer of retinae of 8- to 20-week diabetic rats; under EM, these substances were observed depositing in VECs. The retinal VECs also expressed VEGF, bFGF, IGF-I and their receptors. There was no positive expression of other cell types in these retinae, all cell types of retinae in control group, or all cells of retinae of diabetic rats with the course of disease of 1 to 6 weeks. The result of dot blotting revealed that retinal tissue of 20-week diabetic rat expressed p53 and bcl-2 mRNA, and the result of Western blotting revealed that they also expressed p53 and bcl-2 proteins. But retinal tissues of control group did not. Positive expression of bax was not found in the retinae in control group or 1- to 20-week diabetic rats. Conclusion p53, bcl-2 may introduce cell cycle arrest of VECs of retinae in 8- to 20-week diabetic rats. High glucose might stimulate the expression of VEGF, bFGF, IGF-I and their receptors, and the growth factors may keep VECs surviving by self-secretion. (Chin J Ocul Fundus Dis，2003，19：29-33)
Objective To detect the expression of thromhospondin-1 （TSP-1） in gastric cancer and metastaticlymph node tissues， and to study its relationship of TSP-1 to clinicopathologic parameters or tumor angiogenesis. Methods The TSP-1 and vascular endothelial growth factor （VEGF） expressions and microvessel density （MVD） were evaluated by immunohistochemistry in 72 specimens obtained by gastric resection from patients with gastric cancer， including corres-ponding adjacent normal gastric mucosa tissues （distant from cancer ≥5 cm） and lymph nodes surrounding cancer. A semiquantitative scoring system was used for evaluating the staining. The relationship of TSP-1 to VEGF expression， MVD， or clinicopathologic parameters was analyzed. Results ① TSP-1 positive expression rate was 45.8% （33/72） in the primary gastric cancer tissues， 90.3% （65/72） in the corresponding adjacent normal gastric mucosa tissues， and 50.8% （30/59） in the metastatic lymph nodes tissues. The expressions of TSP-1 in the primary gastric cancer tissues and metastatic lymph nodes tissues were significantly lower than those in the adjacent normal gastric mucosa tissues （χ2=32.710，P=0.000；χ2=25.298， P=0.000）. The expression of TSP-1 had no statistical significance in the primary gastric cancer tissues as compared with in the metastatic lymph nodes tissues （χ2=0.327， P=0.568）. ② The expression of TSP-1 in the metastatic lymph nodes tissues was significantly lower than that in the non-metastatic lymph nodes tissues （Z=-2.573， P=0.010）. ③The expression of TSP-1 in the primary gastric cancer tissues and metastatic lymph nodes tissues suggested a negative correlation with VEGF （rs=-0.309， P=0.008；rs=-0.269， P=0.040） and MVD （rs=-0.348， P=0.003；rs=-0.272， P=0.037）. Conclusions TSP-1 expression is down-regulated and has a negative correlation with VEGF and MVD in the primary gastric cancer and the metastatic lymph nodes tissues. According to the present results， it seems likely that TSP-1 is a tumor angiogenesis inhibitor.
The transforming growth factor-β1 (TGF-β1)/Smad3 signal pathway is related to mutiple physiological and pathological generation mechanism of human being. Up to date, however, the spacial and time information on the phosphorylated Smad3 is still unclear. In this study, the process of Smad3 phosphorylation was observed under the physiological state in the living cells. Firstly, the ECFP-Smad3-Citrine (Smad3 biosensor) fusion protein expression vector was constructed and identified. Then the Smad3 biosensor was transfected into 293T cells. The transfection efficiency and the expressions of fusion proteins were observed in 24 hours. Thirdly, Smad3 biosensor flurorescence resonance energy transfer (FRET) was observed with the inversion fluorescence microscope and measured by the MetaFlour FRET 4.6 software. Smad3 biosensor transfection efficiency was nearly 40% and the fusion protein was seen under the fluorescence microscope. The FRET ratio of Smad3 biosensor in living 293T cells was decreased after 10 minutes incubation with the ligand of TGF-β1. The period of decreasing CFP and enhancing Citrine signals was about 300 seconds. With the technology of FRET, the TGF-β1/Smad3 signal pathway could be real time monitored dynamically under the physiological condition in living cells.
Objective To explore the effect of membrane surface nucleolin （NCL） on activation of epidermal growth factor receptor （EGFR） signaling. Methods Immunohistochemistry was used to identify the expressions of membrane surface NCL or EGFR in pallilary thyroid carcinoma （PTC） tissues. The level of phosphorlated EGFR in TPC-1 cells was observed by Western blot. TPC-1 cells invasion capacity was detected by Transwell assay. Results The posi-tive expression rates of membrane surface NCL and EGFR in PTC tissues were 100% （56/56） and 80.4% （45/56） respe-ctively， while the expressions of NCL and EGFR were related with lymph node metastasis （P＜0.05）. There was posi-tive correlation between the expressions of NCL and EGFR （r=0.635， P＜0.01）. Western blot showed that anti-NCL or anti-EGFR of TPC-1 cells could inhibit the expression of phosphorlation EGFR （P＜0.01）. Transwell assay showed the number of membrane-invading cells were reduced significantly in anti-NCL group anti-EGFR group （P＜0.01）. Conclusions Membrane surface NCL may be a kind of indispensable component in activation of EGFR signaling， by which EGFR can participate in growth and invasion of tumors. NCL can be used as a target for developing a new field of tumor treatment.
Objective To investigate the effects of exogenous bone morphogenetic protein(BMP) and transforming growth factor-β(TGF-β) on biomechanical property for ulna of fracture healing.Methods Thirty-six adult rabbits were made the model of right ulnar fracture and treated locally with TGF-β/PLA, BMP/PLA，TGF-β+BMP/PLA or PLA(as control group). Fracture healing was evaluated by measurement of the mechanical parameters and geometric parameters.Results As compared with control group, the geometric parameters, the bending broken load, the ultimatebending strength, the bending elastic modulus, the ultimate flexural strength, the flexural elastic modulus, the ultimate compressing strength, the compressingelastic modulus, and the ultimate tensile strength for ulna of fracture healingincreased significantly in the treatment groups(P＜0.01). These parameters were higher in TGF-β+BMP/PLA group than in TGF-β/PLA group or in BMP/PLA group andin TGF-β/PLA group than in BMP/PLA group(P＜0.05). There was no significant difference in bone density between the treatment groups and control group. Conclusion Local application of exogenous TGF-β and BMP canincrease the callus formation and enhance biomechanical strength of bone after fracture healing. A combination of TGF-β and BMP has synergetic effect in enhancing fracture healing.
For observation of the change of transforming growth factor-beta 1 (TGF-beta 1) gene expression in the process of skin wound healing, the following experiments were performed. Sixteen Wistar rats were chosen. At each side of the rat’s back, a 1 cm x 1.5 cm middle-thick skin wound was made. After 3, 6, 9 and 12 days, the specimens were taken from the wounds. For each specimen, half of it was used for RNA extraction, and underwent dot blotting; and the other half was frozen immediately and underwent in situ hybridization. The probes were dig-labeled PDGF-BB cDNA probe and TGF-beta 1 probe. The results showed that TGF-beta 1 gene was expressed mainly in fibroblast, epithelial cell and capillary endothelial cell. The peak of TGF-beta 1 mRNA content was in the 6th day postoperatively. After that, the content of TGF-beta 1 decreased to normal. It was suggested that TGF-beta 1 gene expression was in close relation with healing process. TGF-beta 1 may play an important regulatory role in the skin wound healing.
ObjectiveTo investigate the mechanism of G protein coupled receptor kinase interacting protein 1 (GIT1) affecting angiogenesis by comparing the differentiation of bone marrow mesenchymal stem cells (BMSCs) differentiated into endothelial cells between GIT1 wild type mice and GIT1 gene knockout mice.MethodsMale and female GIT1 heterozygous mice were paired breeding, and the genotypic identification of newborn mice were detected by PCR. The 2nd generation BMSCs isolated from GIT1 wild type mice or GIT1 gene knockout mice were divided into 4 groups, including wild type control group (group A), wild type experimental group (group A1), GIT1 knockout control group (group B), and GIT1 knockout experimental group (group B1). The cells of groups A1 and B1 were cultured with the endothelial induction medium and the cells of groups A and B with normal cluture medium. The expressions of vascular endothelial growth factor receptor 2 (VEGFR-2), VEGFR-3, and phospho-VEGFR-2 (pVEGFR-2), and pVEGFR-3 proteins were detected by Western blot. The endothelial cell markers [von Willebrand factor (vWF), platelet-endothelial cell adhesion molecule 1 (PECAM-1), and vascular endothelial cadherin (VE-Cadherin)] were detected by flow cytometry. The 2nd generation BMSCs of GIT1 wild type mice were divided into 4 groups according to the different culture media: group Ⅰ, primary cell culture medium; group Ⅱ, cell culture medium containing SAR131675 (VEGFR-3 blocker); group Ⅲ, endothelial induction medium; group Ⅳ, endothelial induction medium containing SAR131675. The endothelial cell markers (vWF, PECAM-1, and VE-Cadherin) in 4 groups were also detected by flow cytometry.ResultsWestern blot results showed that there was no obviously difference in protein expressions of VEGFR-2 and pVEGFR-2 between groups; and the expressions of VEGFR-3 and pVEGFR-3 proteins in group A1 were obviously higher than those in groups A, B, and B1. The flow cytometry results showed that the expressions of vWF, PECAM-1, and VE-Cadherin were significantly higher in group A1 than in groups A, B, and B1 (P<0.05), and in group B1 than in groups A and B (P<0.05); but no significant difference was found between groups A and B (P>0.05). In the VEGFR-3 blocked experiment, the flow cytometry results showed that the expressions of vWF, PECAM-1, and VE-Cadherin were significantly higher in group Ⅲ than in groupsⅠ, Ⅱ, and Ⅳ, and in group Ⅳ than in groups Ⅰ and Ⅱ (P<0.05); but no significant difference was found between groups Ⅰ and Ⅱ (P>0.05).ConclusionGIT1 mediates BMSCs of mice differentiation into endothelial cells via VEGFR-3, thereby affecting the angiogenesis.
Objective To investigate the effects of Hep-A and Hep-B on vascular endothelial growth factor (VEGF)-induced breakdown of blood-retinal barrier. Methods The mice were subcutaneously injected vehicle, Hep-A or Hep-B 10 mg/kg twice a day for 5 days. Then, 1 μl of 10-6mol/L VEGF were intravitreous injected. After 6 hours, 13.7×104Bq/g3H-mannital were injected intraperitoneally. The mice were sacrificed and the retinas, lungs, kidneys were removed and examined for radioactivity. The result were analyzed using SPSS software to calculate and compare retina/lung and etina/kidney leakage ratio among groups of different treatment. Result The retina/lung and retina/kidney leakage ratio were 0.38±0.04 and 0.21±0.03 respectively in normal mice; increased significantly to 1.05±0.11 and 0.46±0.04 respectively in model mice, both Plt;0.01 compared to those in normal mice; decreased to 0.59±0.06 and 0.32±0.03 respectively in mice treated with Hep-A, both Plt;0.01 compared to those in model mice; decreased 0.54±0.04 and 0.35±0.03 in mice treated with Hep-B,both Plt;0.01 compared to those in model mice. Conclusion Hep-A and Hep-B can significantly reduce VEGF-induced breakdown of blood-retinal barrier in mice. Chin J Ocul Fundus Dis，2004，20：352-354)
Objective To investigate clinical significance of serum VEGF-C level and C-erbB-2 protein expression in patients with breast cancer. Methods Sixty-two female patients with breast invasive ductal cancer and breast benign lesion were respectively selected. Serum VEGF-C level was detected by enzyme-linked immunosorbent assay (ELISA) before operation and at one month after operation, and C-erbB-2 protein expression in tissues of breast cancer was detected by immunohistochemistry. Then, the relationship between serum VEGF-C level and clinicopathologic characteristics and C-erbB-2 protein expressions wereas analyzed. Results The serum VEGF-C level before operation in breast cancer patients〔(279.65±17.34) pg/ml〕 was significantly higher than that in breast benign lesions patients 〔(167.26±12.15) pg/ml〕, P＜0.01. In breast cancer patients, the serum VEGF-C level before operation was higher than that at one month after operation 〔(209.45±15.23) pg/ml〕, P＜0.01. The serum VEGF level was related to tumor stage (P＜0.05) but not to patient age, tumor size, menopause status , lymph node metastasis or not and ER and PR expression (Pgt;0.05). The positive expression rate of C-erbB-2 protein in breast cancer patients (54.84%, 34/62) was significantly higher than that in breast benign lesion patients (11.29%, 7/62), P＜0.01. Moreover, the positive expression rate of C-erbB-2 protein in breast cancer patients with axilla lymph node metastasis (69.44%) was significantly higher than that without axilla lymph node metastases (34.62%), P＜0.05. The serum VEGF level increased with increasing expression intensity of C-erbB-2 protein and there was positive correlation between them (r=0.813，P＜0.05). Conclusions The serum VEGF-C level in breast cancer may be conducted as an assisted marker to differential diagnosis of breast tumor. C-erbB-2 is related to lymph node metastasis of breast cancer patients. There is synergistic effect between VEGF-C and C-erbB-2 in the lymph node metastasis way of breast cancer.
OBJECTIVE: To investigate the effect of nerve growth factor(NGF) on the burn wound healing and to study the mechanism of burn wound healing. METHODS: Six domestic pigs weighting around 20 kg were used as experimental animals. Twenty-four burn wound, each 2.5 cm in diameter, were induced on every pigs by scalding. Three different concentrations of NGF, 1 microgram/ml, 2.5 micrograms/ml, 5 micrograms/ml were topically applied after thermal injury, and saline solution used as control group. Biopsy specimens were taken at 3, 5 and 9 days following treatment and immunohistochemistry method was used to detect the epidermal growth factor(EGF), EGF receptor (EGF-R), NGF, NGF receptor (NGF-R), NGF, NGF-R, CD68 and CD3. RESULTS: The expression of EGF, EGF-R, NGF, NGF-R CD68 and CD3 were observed in the experimental group, especially at 5 and 9 days, no expression of those six items in the control group. CONCLUSION: NGF can not only act directly on burn wound, but also modulate other growth factors on the burn wound to accelerate the healing of burn wound.