Objective To observe the expression of integrin αVβ3 in vascular endothelium cultured in vitro at different time points under different level of shear stress. Methods（1）We established a vascular culture system in vitro which could provide steady flow with different level of shear stress, and tested the flow stability when loading different level of shear stress. （2） A total of 50 rabbits were randomly divided into low shear stress group （5 dyn/cm2, n=25）and normal shear stress group（20 dyn/cm2, n=25）. Rabbits in each group were further randomly divided into five different time points as 2 h, 4 h, 8 h, 16 h and 24 h（n=5 at each time point）. The descending aorta of rabbits were harvested and cultured in the vascular culture system in vitro under different level of shear stress. The expression sites and intensity of αVβ3-Integrin in vascular endothelium were examined at 5 different time points in both groups by immunohistochemical staining. Results The vascular culture system in vitro was stable in providing laminar flow with different level of shear stress required for the experiment. Vascular endothelium expressions of αVβ3-Integrin in the low shear stress group were in high level at all the 5 time points and reached its summit at 16 h, when the mean optical density（MOD）value was （1.995±0.194）×10-2. In the normal shear stress group, the MOD value decreased time-dependently at the 5 time points. The MOD values at 2 h （0.059±0.005）×10-2 and 4 h（0. 049±0.002）×10-2 were significantly higher than those at other time points （P＜ 0.05）. The αVβ3-Integrin MOD values of the low shear stress group were significantly higher than those of the normal shear stress group at all the 5 respective time points （P=0.000）. Conclusion Low shear stress can significantly promote the expression of αVβ3-Integrin while normal shear stress decreases the expression of αVβ3-Integrin in vascular endothelium cultured in vitro.
Objective To observe the effect of epidermal growth factor (EGF) on integrin alpha;5 expression and its influence on human retinal pigment epithelium (RPE) cells.Methods Human RPE cells were treated in vitro with 0.1,1.0,10.0,20.0 and 100.0 ng/ml of EGF, the mRNA and protein of integrin alpha;5 was measured by reverse transcription polymerase chain reaction（RT-PCR）and flow cytometry. Human RPE cells were cultured under 4 conditions including DMEM/F12,DMEM/F12+10 ng/ml EGF, DMEM/F12+10 ng/ml EGF+rabbit antihuman integrin alpha;5 antibody (1∶100)，DMEM/F12+10 ng/ml EGF+rabbit antihuman vimentin antibody (1∶100), and their proliferation and migration were measured by methylthiazole tetrazolium（MTT）and Boyden chamber.Results The integrin alpha;5 mRNA level of human RPE cells was not changed after 12 hours of EGF stimulation (F=0.618, P=0.687), however it was induced in a dosedependent manner after 24 and 48 hours of EGF stimulation (F=465.303, 212.340; P=0.000,0.000).The protein level of integrinalpha;5 was higher in 10 ng/ml EGF stimulation compared with the control group and 0.1 ng/ml group（P＜0.01）.MTT and Boyden chamber showed that the integrin alpha;5 expression increased the proliferation and migration of human RPE cells. Conclusion EGF can induce integrin alpha;5 expression,thus increase the proliferation and migration of human RPE cells.
Objective o explore the effect and mechanisms of transmembrane 4 super family (TM4SF) in digestive system cancer. Methods Articles were reviewed to discuss the biological characteristics of TM4SF in digestive system cancer. Results TM4SF played an important role in migration and invasion of digestive system cancer, including pancreatic cancer, gastric cancer, colorectal cancer, hepatic cancer, esophageal cancer, and so on. TM4SF modulated the cell biological activities by microdomains which were fixed on cell membrane, such as adhesion, migration, invasion, and proliferation. Conclusion TM4SF may be used to predict the metastasis and prognosis of digestive system cancer and may be the targets of therapy of it in the future.
Abstract: Objective To observe the expression of integrinlinked kinase (ILK) and matrix metalloproteinases9 (MMP9) in human nonsmall cell lung cancer (NSCLC) and investigate the correlation of ILK and MMP9 expression with the prognosis of NSCLC. Methods The expression of ILK and MMP9 in 75 specimens of NSCLC resected from January 2002 to January 2004 were detected by immunohistochemistry. According to the median of integral optical density (IOD), all patients were divided into the high or low ILK expression group and the high or low MMP-9 expression group. The relativity of ILK and MMP9 was determined, and the relationship of survival time with clinical features including expression of ILK and MMP-9 was compared by Logrank test. Results Both ILK and MMP-9 were expressed in NSCLC specimens. The expression between ILK and MMP-9 was positively correlated in 75 patients of our group (r=0.79, Plt;0.05). Patients with lower expression of ILK and MMP9 had a significantly longer survival time than those with higher expression of ILK and MMP-9 in the postoperative followup (χ2=15.067,14301,Plt;0.05). The survival time was not correlated with sex,age,smoking history or pathological type(χ2=0450,0078, 1.460, 1.623，Pgt;0.05), while tumor diameter, lymph node metastasis, TNM stage, the expression of ILK and MMP-9 significantly influenced the survival time (χ2=3.963, 15.169,20.529, 15.067，14.301，Plt;0.05). Conclusion The expression of ILK and MMP9 affects the prognosis of NSCLC. MMP-9 may advance infiltration and metastasis of tumor cells through ILK pathway. In summary, the expression of ILK and MMP9 may play an important role in the evaluation of prognosis for patients with NSCLC.
【Abstract】Objective To introduce the current research status, value and development future of Arg-Gly-Asp (RGD) peptides in diagnosis and treatment of neoplasms. Methods The current literatures on advances about RGD peptides in diagnosis and treatment of neoplasms were reviewed. Results RGD peptides, specificly recognizing and combining with integrin receptors, exist in extracellular matrix (ECM) of many kinds of organisms. After combining with integrin receptors, extrinsic RGD peptides can prevent tumor cells from adhering to ECM and migrating as the competitive inhibitor of intrinsic RGD peptides, suppress agiogenesis and induce tumor cells apoptosis, showing potential value of tumor specific imaging by targetal labelling neoplasms and treating tumors combining with other methods.Conclusion RGD peptides may be a new drug for diagnosis and treatment of neoplasms.
ObjectiveTo investigate the value of integrin αvβ3 targeted microPET/CT imaging with 68Ga-NODAGA-RGD2 as radiotracer for the detection of osteosarcoma and theranostics of osteosarcoma lung metastasis.MethodsThe 68Ga-NODAGA-RGD2 and 177Lu-NODAGA-RGD2 were prepared via one-step method and their stability and integrin αvβ3 binding specificity were investigated in vitro. Forty-one nude mice were injected with human MG63 osteosarcoma to established the animal model bearing subcutaneous osteosarcoma (n=21), osteosarcoma in tibia (n=5), and osteosarcoma pulmonary metastatic (n=15). The microPET-CT imaging was carried out in 3 animal models at 1 hour after tail vein injection of 68Ga-NODAGA-RGD2. Biodistribution study of 68Ga-NODAGA-RGD2 was performed in animal model bearing subcutaneous osteosarcoma at 10, 60, and 120 minutes. The animal model bearing pulmonary metastatic osteosarcoma was injected with 177Lu-NODAGA-RGD2 at 7 weeks after model establishment to observe the therapeutic effect of pulmonary metastatic osteosarcoma. Histological and immunohistochemistry examinations were also done to confirm the establishment of animal model and integrin β3 expression in animal models bearing subcutaneous osteosarcoma and bearing pulmonary metastatic osteosarcoma.Results68Ga-NODAGA-RGD2 and 177Lu-NODAGA-RGD2 had good stability in vitro with the 50% inhibitory concentration value of (5.0±1.1) and (6.5±0.8) nmol/L, respectively. The radiochemical purity of 68Ga-NODAGA-RGD2 at 1, 4, and 8 hours was 98.5%±0.3%, 98.3%±0.5%, and 97.9%±0.4%; while the radiochemical purity of 177Lu-NODAGA-RGD2 at 1, 7, and 14 days was 99.3%±0.7%, 98.7%±1.2%, and 96.0%±2.8%. 68Ga-NODAGA-RGD2 microPET-CT showed that the accumulation of 68Ga-NODAGA-RGD2 in animal models bearing subcutaneous osteosarcoma and osteosarcoma in tibia and in lung metastasis as small as 1-2 mm in diameter of animal model bearing pulmonary metastatic osteosarcoma. Biodistribution study of 68Ga-NODAGA-RGD2 in animal model bearing subcutaneous osteosarcoma revealed rapid clearance from blood with tumor peak uptake of (3.85±0.84) %ID/g at 120 minutes. The distribution of 177Lu-NODAGA-RGD2 in lung metastasis was similar with 68Ga-NODAGA-RGD2. The number and size of osteosarcoma metastasis decreased at 2 weeks after 177Lu-NODAGA-RGD2 administration and integrin targeting specificity was confirmed by pathology examination.Conclusion68Ga-NODAGA-RGD2 was potential for positive imaging and early detection of osteosarcoma and metastasis. Targeted radiotherapy with 177Lu-NODAGA-RGD2 was one potential alternative for osteosarcoma lung metastasis.
OBJECTIVE: To study the expression of type I collagen and its receptor system-integrin alpha 2 beta 1 in different passages of osteoblasts. METHODS: The expression of type I collagen and integrin alpha 2 beta 1 in the primary, sixth and fifteenth passage of osteoblasts were detected by S-P immunohistological staining technique, and their mRNA expression by quantity RT-PCR technique. RESULTS: Type I collagen and integrin alpha 2 beta 1 were expressed in different passages of osteoblasts and there was no significant difference among three passages by immunohistological technique. Their mRNA expression was gradually decreased with subculture. CONCLUSION: Type I collagen promotes the adhesion and phenotype expression of osteoblasts through its receptor-integrin alpha 2 beta 1. The reductive expression of type I collagen-receptor system will decline the phenotype of osteoblasts.
Objective To review the role of integrin in nervous system injury and its repair, and to analyze the possible mechanisms. Methods Recent l iterature concerning integrin and its role in nervous system injury was reviewed and analyzed. Results Integrin and its related signall ing pathway were involved in nervous system injury, especially hypoxicischemic nervous injury, and their repair processes. Conclusion Intervention of integrin signall ing pathway would be a potential strategy to treat nervous system injury, especially hypoxic-ischemic nervous injury.
【Abstract】Objective To observe the changeable expressions of vascular endothelial growth factor (VEGF) and integrin β3 during the angiogenetic process of granulation tissue. Methods mRNA and protein of VEGF and integrin β3 in human normal subcutaneous tissue, proliferative granulation tissue and mature granulation tissue were observed by RT-PCR and immunohistochemistry staining. Results The expressions VEGF and integrin β3 were low in normal subcutaneous tissue and were much higher in proliferative granulation tissue. When the granulation tissue was mature, the expression was decreased again. Conclusion VEGF and integrin β3 are important regulating factors in ngiogenesis.
ObjectiveTo observe the effect of integrin β8 on the neuronal apoptosis after hypoxia ischemia (HI) in astrocyte/neuron co-culture system. MethodsAstrocytes and neurons were cultured in vitro from cerebral cortex of the P1-3 days Sprague Dawley rats and E16 days fetal rats, respectively. Immunocytochemistry staining was used to identify the purity of cells. Integrin β8 mRNA expression was qualified in the astrocytes at 12 hours, 1 day, and 2 days after HI and reoxygenation (experimental group) and in normal astrocytes (control group) by RT-PCR. Integrin β8 small interering RNA (siRNA) system was established to specifically block astrocyte β8 expression, the efficiency of integrin β8 inhibition was detected by real-time fluorescent PCR. The astrocytes and neurons were co-cultured to established the astrocyte/neuron co-culture system. The neuronal apoptosis was detected with TUNEL in the normal neurons/astrocytes group (co-cultured HI group), the astrocytes infected by integrin β8 siRNA for 2 days/normal neurons group (β8 RNA interference group), and normal neurons in vitro with HI treatment group (HI group) at 1 day after HI and reoxygenation. The normal neurons without treatment as control (control group). ResultsGlial fibrillary acidic protein and neuronal nuclei staining suggested a purity of more than 90% in cultured cells. HI resulted in an increase of integrin β8 mRNA expression at 12 hours after reoxygenation in astrocytes, which peaked at 1 day after reoxygenation, then slowly decreased and remained higher at 2 days, showing significant differences between control group and experimental group and among different time points in experimental group (P<0.05). RNA interference efficiency was most significant at 2 days after astrocytes infected with integrin β8 siRNA (P<0.05). The neuronal apoptosis was significantly increased in HI group, co-cultured HI group, and β8 RNA interference group when compared with control group (P<0.05). But neuronal apoptosis index (AI) was significantly decreased in co-cultured HI group and β8 RNA interference group when compared with HI group (P<0.05). The significant difference of AI was found between co-cultured HI group and β8 RNA interference group (P<0.05). ConclusionIntegrin β8 expression can be induced with hypoxic-ischemic brain damage, leading to decreased AI of neurons and obvious protective effect.