Objective To evaluate the role for integrins in tumor angiogenesis. MethodsLiteratures in recent years were reviewed. ResultsIntegrins played an important role in tumor angiogenesis and integrins had a close relation to vascular growth factors. Conclusion Inhibitors of integrins will be a promising way to cure tumors.
【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.
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.
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.
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 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.
Objective Epidermal stem cells (ESCs) can actively partici pate in wound heal ing and enhance reepithel ial ization. To establ ish ideal diabetes mell itus (DM) rat models and to investigate the expression of keratin 19 (K19),β1-integrin, β-catenin, and prol iferating cell nuclear antigen (PCNA) in ESCs of DM rat model, then to study the potential mechanism of difficult recovering wounds of diabetic skin. Methods Twenty male SD rats (weighing 250-300 g) were dividedinto DM group and normal control group randomly (n=10). The DM rat model was made by intraperitoneal injected 65 mg/kg streptozocin (STZ), the normal control group was not treated. At 4 weeks after injection, pancreatic tissue was harvested for HE staining in two groups. The ESCs isolated from full-thickness skins of the back of two group rats were culutured and identified. The 2nd passage of ESCs were obtained for immunocytochemical staining of K19, β1-integrin, β-catenin, and PCNA. Meanwhile, the cell cycle were measured by flow cytometry. The cell colony formation rates were detected after 1 week. Results The achievement ratio of DM rat model was 90% with good stabil ity. HE staining showed that the number of islet cells significantly decreased with degeneration and necrosis in DM group; the structure of islet cell was clear without degeneration and necrosis in normal control group. The integral absorbance values of positive expression for K19, β1-integrin, β-catenin, and PCNA in ESCs of DM group (82.63 ± 14.77, 21.59 ± 4.71, 6.49 ± 6.58, and 90.77 ± 12.44, respectively) were significantly lower than those in the normal control group (151.24 ± 42.83, 54.48 ± 17.43, 116.39 ± 9.26, and 110.62 ± 20.67, respectively) (P lt; 0.01). The clone forming efficiency of ESCs in DM group (6.43% ± 1.01% ) was significantly lower than that in the normal control group (11.37% ± 1.62%) (P lt; 0.01). Flow cytometry indicated that 88.89% of cultured ESCs in the DM group were in resting state/ pre-DNA-synthetic gap (G0/G1), and the apoptosis rate was 3.98%; 91.50% in the normal control group and the apoptosis rate was 0. Conclusion The DM rat model can be effectively induced by intraperitoneal injected 65 mg/ kg STZ. The decreased amount and the low prol iferation and differentiation capacity of ESCs may be one of the important mechanisms of difficult recovering wounds of DM rats.
Objective To provide theoretical evidence for clinical application of the epidermal stem cells after an investigation on changes of the epidermal stem cells during the survival process after the fullthickness skin autograft. Methods On the backs of 42 Wistar rats, orthotopic transplantation models (1.5 cm×1.5 cm) of the fullthickness skin autograft were made. According to the time of the specimen taking, at 1, 3, 5, 7, 14, 21 and 30 days after operation, the rats were randomly divided in 7 groups (Groups 1-7). Specimens taken in each group before operation were used as controls. At each time point, the gross observation was made on the transplanted skin flaps, from which the skin tissues were harvested at each time point before and after operation. The routine pathological and the immunohistochemical examinations were performed on the specimens, which were stained by HE and were observed for immunohistochemical changes and the changes in the cells positive for integrinβ-1 and p63. Results All the fullthickness skin autografts survived 3 days after operation except the skin autograft in 1 rat in both Group 5 and Group 6, which was infected around the transplanted skin flap. In Groups 1-4, cell edema, inflammatory cell infiltration, and increased fibrocytes were observed. In Groups 5-7, the maturity degree of the epithelial cells became higher and higher, and the fibrocyte proportion was lowered. In each group the cell positivity rate for integrin β1 was lower than the cell positivity rate for p63. The positive cells were arranged in disorder, distributed into the layers of the epidermis and gradually concentrated in the basal layer of the epidermis and the bulge of the folliculus pili. The positive cells were also found in the other layers of the epidermis.The positive cells were gradually decreased in number, and reached the lowest level in Group 2. There was a significant difference in the above variables in Groups 1,2,3,5,6 and 7 between before and after operations (P＜0.05). Conclusion During the survival process of the fullthickness skin autograft, the proportion of theepidermal stem cells is gradually decreased at first; Then, the proportion isgradually increased, even beyond the normal level; finally, the proportion is decreased again. The distribution of the epidermal stem cells appear in disorder, almost distributed in the layers of the epidermis; finally, the almost normal distribution can be found.
OBJECTIVE: To investigate the selection and identification of human keratinocyte stem cells(KSC) in vitro. METHODS: According to the characteristics of KSC which can adhere to extracellular matrix very fast, we selected 3 groups of different time(5 minutes, 20 minutes and 60 minutes) and unselected as control group. And the cells were identified by monoclone antibody of beta 1-integrin and cytokeratin 19 (Ck19), then the image analysis was done. Furthermore we analyzed the cultured cells with flow cytometer(FCM) and observed the ultrastructure of the cell by transmission electron microscope(TEM). RESULTS: The cell clones formed in all groups after 10 to 14 days, while the cells of 5 minute group grew more slowly than those of the other groups, however, the clones of this group were bigger. The expression of beta 1-integrin and Ck19 were found in all groups. The positive rate of beta 1-integrin was significant difference between 5 minute group and the other groups (P lt; 0.05). And the expression of Ck19 was no significant difference between 5 minute group and 20 minute group(P gt; 0.05), and between 60 minute group and control group. But significant difference was observed between the former and the later groups(P lt; 0.05). The result of FCM showed that most cells of the 5 minute group lied in G1 period of cell cycle, which was different from those of the other groups. At the same time, the cells of 5 minute group were smaller and contained fewer organelles than those of the other groups. CONCLUSION: The above results demonstrate that the cells of 5 minute group have a slow cell cycle, characteristics of immaturity, and behaving like clonogenic cells in vitro. The cells have the general anticipated properties for KSC. So the KSC can be selected by rapid attachment to extracellular matrix and identified by monoclone antibody of beta 1-integrin and Ck19.