RESUMO
A pterygium is characterized by abnormal fibrovascular corneoconjunctival tissue. A number of investigations have attempted to elucidate this incompletely understood pathology. Since vascular endothelial growth factor (VEGF) and p53 are known to participate in tumor vascularization, our purpose was to study VEGF and p53 expression in active primary and recurrent pterygium from Tunisian patients. To this end, 15 cases of active primary pterygium and five cases of recurrent pterygium from Tunisia were studied by immunohistochemistry. Antibodies raised against VEGF and p53 were used to analyze the distribution and expression of these markers in pterygium and normal human conjunctiva were used as negative control. VEGF and p53 proteins were found in all cases of primary pterygium in epithelial, fibroblast and vascular endothelial cells. Active primary and recurrent pterygium have different patterns of expression. In primary pterygium, an important variability of p53 and VEGF expression was observed. However, in recurrent pterygium, p53 immunoreactivity was weak to moderate, whereas VEGF immunoreactivity was strong. In normal human conjunctiva, VEGF and p53 expression was weak to negative. The overexpression of VEGF in active primary and recurrent pterygium suggests that angiogenesis may play a role in pterygium pathogenesis and the expression of p53 in active primary pterygium, which might be associated with its mutated form, supports the hypothesis that actinic radiation may be involved in the genesis of pterygium. Thus, VEGF and p53 may be useful biomarkers for understanding the physiopathology of pterygium.
Assuntos
Neovascularização da Córnea/genética , Pterígio/metabolismo , Fator A de Crescimento do Endotélio Vascular/biossíntese , Adulto , Idoso , Túnica Conjuntiva/metabolismo , Feminino , Genes p53 , Humanos , Técnicas Imunoenzimáticas , Masculino , Pessoa de Meia-Idade , Pterígio/epidemiologia , Pterígio/genética , Recidiva , Proteína Supressora de Tumor p53/biossíntese , Tunísia/epidemiologia , Fator A de Crescimento do Endotélio Vascular/genética , Adulto JovemRESUMO
PURPOSE: Diabetic fibrovascular membranes are the main pathological changes of proliferative diabetic retinopathy that can cause serious complications leading to blindness. Since the mechanism of fibrovascular membrane development is still unknown, the aim of our study was to identify potential biomarkers for this pathology. To this end, we analyzed the simultaneous expression of ICAM-1, VCAM-1 and VEGF within tissues of diabetic fibrovascular membranes. PATIENTS AND METHODS: Fibrovascular membranes were taken from nine diabetic patients with proliferative diabetic retinopathy. The fibrovascular membrane specimens were analyzed by immunohistochemistry to determine ICAM-1, VCAM-1 and VEGF expression. Controls were collected on nine normal conjunctivas removed during senile cataract surgery. RESULTS: Coexpression of ICAM-1, VCAM-1 and VEGF was found in most of the diabetic fibrovascular membranes studied. Thus, ICAM-1 was positive in eight of nine membranes (82%), VCAM-1 in seven of nine membranes (78%) and VEGF in all the membranes. CONCLUSIONS: The substantial overexpression of adhesion molecules ICAM-1, VCAM-1 and of VEGF suggests that these molecules might contribute to the development of fibrovascular membranes in patients with proliferative diabetic retinopathy, and that they could constitute suitable markers of this pathology.
Assuntos
Retinopatia Diabética/patologia , Molécula 1 de Adesão Intercelular/análise , Vasos Retinianos/patologia , Molécula 1 de Adesão de Célula Vascular/análise , Fator A de Crescimento do Endotélio Vascular/análise , Adulto , Idoso , Envelhecimento , Biópsia , Extração de Catarata , Moléculas de Adesão Celular/análise , Túnica Conjuntiva/patologia , Progressão da Doença , Feminino , Humanos , Imuno-Histoquímica/métodos , Molécula 1 de Adesão Intercelular/genética , Masculino , Pessoa de Meia-Idade , Valores de Referência , Molécula 1 de Adesão de Célula Vascular/genética , Fator A de Crescimento do Endotélio Vascular/genética , Adulto JovemRESUMO
PURPOSE: Recent research has incriminated adhesion molecules in the pathogenesis of diabetic retinopathy. These molecules have been found to be expressed in many cells participating in inflammatory processes and neovascularization. The purpose of our investigation was to study the expression of intercellular adhesion molecule type 1 (ICAM-1) in the conjunctiva of diabetic patients without retinopathy in comparison with normal human conjunctiva. PATIENTS AND METHODS: Fifteen conjunctival biopsies were obtained from diabetic patients without retinopathy. The ocular fundus examination and retinal fluorescein angiography were normal. The normal human conjunctiva were taken from five patients undergoing senile cataract surgery. Immunohistochemical analysis consisted of indirect immunoperoxidase using the monoclonal antibody ICAM-1. RESULTS: The adhesion molecule ICAM-1 was immunolocalized in epithelial, vascular endothelial, and inflammatory cells. The expression of this molecule was different in diabetic patients for the same duration. In the normal human conjunctiva, the expression of ICAM-1 was very low. CONCLUSION: This preliminary study shows that ICAM-1 is present in the conjunctiva of diabetic patients without retinopathy and thus may add new insights into the pathogenesis of diabetic retinopathy.