RESUMO
Pterygium is a degenerative, fibrovascular and hyperplastic growth resulting from a proliferative tissue actively growing from altered limbal stem cells at the corneal-conjunctival junction. However, the pathogenesis of pterygium is still unclear. The aim of this study was to determine the expression of neurotrophic factors (nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), ciliary neurotrophic factor (CNTF), and neurotrophin (NT)-3, NT-4/5) in pterygeal tissue and to confirm whether tumor-necrosis factor-alpha (TNF-alpha) modulates the expression of these neurotrophic factors in primary cultured pterygeal fibroblasts. We looked for expression of these neurotrophic factors in surgically excised pterygia and normal donor limbal tissues by immunohistochemistry and in primary cultured pterygeal and normal subconjunctival Tenon's fibroblasts by Western blot and reverse transcription-polymerase chain reaction (RT-PCR). Expression of CNTF and NT-4/5 is increased in pterygeal tissues compared with normal tissue, and production of CNTF is stimulated in pterygeal fibroblasts by TNF-alpha but not in normal fibroblasts. This selective stimulation of CNTF in pterygeal fibroblasts suggests that CNTF may play a role in the pathogenesis of pterygium.
Assuntos
Fibroblastos/metabolismo , Fatores de Crescimento Neural/metabolismo , Pterígio/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Células Cultivadas , Fator Neurotrófico Ciliar/genética , Fator Neurotrófico Ciliar/metabolismo , Fibroblastos/efeitos dos fármacos , Fibroblastos/patologia , Expressão Gênica/efeitos dos fármacos , Humanos , Limbo da Córnea/citologia , Limbo da Córnea/efeitos dos fármacos , Limbo da Córnea/metabolismo , Fator de Crescimento Neural/genética , Fator de Crescimento Neural/metabolismo , Fatores de Crescimento Neural/genética , Pterígio/tratamento farmacológico , Pterígio/patologia , RNA Mensageiro/metabolismo , Proteínas Recombinantes/farmacologiaRESUMO
The protein BigH3 is a cell-adhesion molecule induced by transforming growth factor-beta (TGF-beta). It consists of four homologous repeat domains known as FAS1 domains; mutations in these domains have been linked to corneal dystrophy. The fourth FAS1 domain was expressed in Escherichia coli B834 (DE3) (a methionine auxotroph) and purified by DEAE anion-exchange and gel-filtration chromatography. The FAS1 domain was crystallized using the vapour-diffusion method. A SAD diffraction data set was collected to a resolution of 2.5 A at 100 K. The crystal belonged to space group P6(1) or P6(5) and had two molecules per asymmetric unit, with unit-cell parameters a = b = 62.93, c = 143.27 A, alpha = beta = 90.0, gamma = 120.0 degrees.
