The Study Of The Relation Between Vascular Endothelial Growth Factor (VEGF) And Telomerase Expression In Pterygium

Objective: Pterygium was more common in ocular surface diseases .The studies had shown that pterygium was a conjunctival hyperplasia disease, its pathogenesis was still not very clear, may be related to cell proliferation and abnormal apoptosis.Because of high postoperative recurrence of pterygium, data had shown a correlation with cancer , the expression of telomerase in pterygium may be an important reason .It is necessary to conduct in-depth study of telomerase activity.This study had shown telomerase activity and telomerase reverse transcriptase (hTERT) mRNA expression in advanced pterygium. Because pterygium was a proliferative lesions, I also introduced the use of good indicators to reflect the state of cell proliferation - PCNA (proliferating cell nuclear antigen, PCNA), because PCNA as a DNA polymerase auxiliary proteins directly involved in the cells proliferative activity , it contained only small amounts in stationary phase, and started to increase from the late G1 phase, reached the peak in S phase, decreased significantly in G2 phase, M phase.VEGF was a powerful cytokines, which could generate a variety of biological effects. It was a class of glycoproteins, In 1989, Ferrarra purified out it from the culture medium of bovine pituitary follicular stellate cells,It was a member of platelet-derived growth factor (platelet derived growth factor, PDGF) family, the molecular weight was 34 - 45 KD, sequence was highly conserved, widely distributed in human and animal brain, kidney, liver, spleen, pancreas and bone and other organizations, it was the most straightforward promote vascular endothelial cell mitogen and had been secreted as a paracrine stimulator of angiogenesis.And the study found that VEGF was the most powerful angiogenesis promoting factor. It could enhance microvascular permeability, stimulate endothelial cell division, increase tissue factor and the production of certain protease.The Interaction of VEGF and VEGF receptor mainly was through the endothelial cell intracellular signal transduction pathways to cause increased permeability of vessels ,to promote vascular endothelial cell proliferation, migration, thus inducing angiogenesis.Studies had shown that the vessel growth and maturation were highly complex and coordinated process that needs to use a variety of ligand receptor and the completion of a series of sequential activation.Under normal physiological process of vessel growth, such as embryos into, such as bone growth, The signa of VEGF represented major restriction enzyme.In pathological cases, It may appear abnormal VEGF expression in ischemic diseases, hypoxia may stimulate the increased expression of VEGF, cause endothelial cells in a strong mitogenic role to promote angiogenesis, VEGF can increase vascular permeability, in particular, microvascular , cause leakage of plasma proteins into the extracellular matrix, which was composed in the extracellular matrix for the fibroblasts and vascular endothelial cells to provide the conditions to move into matrix, as tumor cells growth and new capillaries .The establishment of networks to provide nutrition.Pterygium in the past had been considered to be a degeneration of conjunctiva.The results of Recent research were that it was the kind of growth process of the disorder.Studies had shown that VEGF was overexpressed in the transgenic mice's skin, It affected on the angiogenesis of the skin, caused that skin was similar to the psoriasis-like inflammatory response. so it was necessary to make experiments from different angles above.To be from the following areas:1. Through the study of telomerase, the pathogenesis of pterygium could be understood in-depth, which could provide new ideas for the prevention and treatment of pterygium.2. Through the study of the expression of VEGF, the occurrence of pterygium could be understood ,which had guiding significance in reducing the relapse rate of pterygium.3.The relationship between the expression of telomerase and VEGF in pterygium. Methods: The 22 specimens came from the out-patients of the Second hospital of Hebei Medical University of surgery patients during January 2009 to September 2009, who were in the incipient period of pterygium. selection criteria: rang from 35 ~ 75 years old, course of the disease from 8 months to 20 years, no other cornea, conjunctiva disease, to exclude glaucoma, iritis , and other retinal disorders. To exclude systemic disease. Be confirmed of pterygium by pathological examination.I also selected 8 normal bulbar conjunctiva specimens as controls. after 10% formalin fixation, routine dehydration, embedded in paraffin for 3μm serial sections, respectively, the VEGF, PCNA, hTERT in these specimens were stained by immunohistochemical staining,and the hTERT by situ hybridization staining. Results judgement: The positive cells had brown-yellow granules in cytoplasm. Light microscope, take five horizons for any cell , at least 500 cells were counted, in order to account for the percentage of positive cells in total cells. A represented the number grade of positive cells, 0 ~ 1% = 0,1 ~ 10% = 1,10 ~ 50% = 2,50 ~ 80% = 3,80 ~ 100% = 4.B represented the color intensity grade of positive cells 0 (negative), 1 (weak positive), 2 (positive), 3 (strong positive) IHS = A×B. Statistical method: IHS =staining power×The positive rate of staining, measurement data were tested by rank test,"a"equaled to 0.05,The results would be dealt with SPSS 16.0 statistical software.Results: 1 the results of VEGF: Comparison of VEGF IHS table in pterygium between the disease group and Normal group,According statistical analysis we concluded that there were significant difference between disease group and the Normal group (Z=-3.324, P=0.001). VEGF protein was mainly localized in the cytoplasm of vascular endothelium and expression of the cytoplasm, nucleus-free coloring. The positive part mainly was the goblet cells in the epithelium .2 the results of PCNA: Comparison of PCNA IHS table in pterygium between the disease group and Normal group,According statistical analysis we concluded that there were significant difference between disease group and the Normal group (Z=-3.371,P=0.001). PCNA antibody expressed mainly in the nucleus.3 the results of hTERT: Comparison of hTERT IHS table in pterygium between the disease group and Normal group, According statistical analysis we concluded that there were significant difference between disease group and the Normal group (Z=-4.256, P=0.000). hTERT antibody expressed mainly in the cytoplasm.4 the results of hTERT mRNA: Comparison of hTERT mRNA IHS table in pterygium between the disease group and Normal group, According statistical analysis we concluded that there were significant difference between disease group and the Normal group (Z= -3.415 , P=0.001). hTERTmRNA mainly was located in cytoplasm, nucleus-free coloring.Conclusions: Comparison of IHS table of VEGF, PCNA, hTERT, hTERT mRNA in pterygium between the disease group and Normal group: Staining level in disease group was significantly higher than the normal group.It was considered that more advanced pterygium in the target which compared with normal group expressed significantly.