RESUMO
BACKGROUND & OBJECTIVES: : Amino acids are general nutrients having anti-diabetic property. The present study was undertaken to investigate the mechanism of anti-diabetic effects of amino acids in human visceral adipocyte cells in high glucose environment. METHODS: : Experiments were carried out in human visceral adipocytes. Adiponectin (APN) siRNAs were designed using Ambion tools. APN mRNA expression was quantified using real-time polymerase chain reaction, and protein level was studied using ELISA. AMP-activated kinase (AMPK) activity was measured and glucose uptake by 2-deoxyglucose uptake method. RESULTS: : Amino acids (proline and phenylalanine) exposure to adipocytes significantly (P <0.01) increased APN mRNA by 1.5-folds when compared to control whereas proline increased APN secretion by 10.6-folds (P <0.01), phenylalanine by 12.7-folds (P <0.001) and alanine by 6.3-folds (P <0.01). Free amino acid-induced AMPK activity and glucose uptake were decreased with the transient knockdown of APN. INTERPRETATION & CONCLUSIONS: : Antidiabetic effect of the tested amino acids was exhibited by increased glucose uptake through the AMPK pathway by an APN-dependent mechanism in human visceral adipocytes. This should be tested and confirmed in in vivo system. Newer treatment modalities with amino acids which can enhance glucose uptake and APN secretion can be developed as drug for treating both diabetes and obesity.
Assuntos
Adiponectina/genética , Diabetes Mellitus/dietoterapia , Glucose/metabolismo , Obesidade/dietoterapia , Proteínas Quinases/genética , Quinases Proteína-Quinases Ativadas por AMP , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Aminoácidos/farmacologia , Células Cultivadas , Diabetes Mellitus/metabolismo , Suplementos Nutricionais , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Hipoglicemiantes/farmacologia , Gordura Intra-Abdominal/efeitos dos fármacos , Gordura Intra-Abdominal/metabolismo , Obesidade/metabolismo , Obesidade/patologia , Fenilalanina/farmacologia , Prolina/farmacologia , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Transdução de Sinais/efeitos dos fármacosRESUMO
We report a immunohistochemical study of expression of VEGF and PEDF in Eales' disease. An enucleated eye from a patient with Eales' disease and an age and sex-matched donor eyeball were subjected to immunohistochemical and histopathological analysis to study the expression of VEGF and PEDF in the retinal region. Strong positive anti-VEGF immunostaining was found around the vessel walls in the retina in the eyeball from the Eales' disease patient compared with the donor control, from which it was almost absent. PEDF staining was detected in the normal donor eyeball retinal layers surrounding the blood vessels, and the photoreceptor and ganglion cell layer, whereas in the eyeball from Eales' disease patient PEDF staining was restricted to the surrounding blood vessels. The strong expression of VEGF in eyes with Eales' disease as opposed to weak expression of PEDF indicates the propensity of the disease to show neovascularization and recurrent hemorrhages.
