Role of IL-1β on the Glutamine Synthetase in Retinal Müller Cells under High Glucose Conditions

Abstract

Purpose: To investigate (1) the role of cytokine interleukin-1ßon the glutamine synthetase in retinal Müller cells under high glucose condition, (2) the mechanism for down-regulation of glutamine synthetase in retinal Müller cells induced by interleukin-1ß under high glucose conditions. Materials and Methods: The effect of interleukin-1ß on the expression of glutamine synthetase and c-Jun in retinal Müller cells under normal and high glucose conditions was measured by immunocytochemistry, Western blot, and real-time (RT) PCR, and was further confirmed by c-Jun siRNA method. Results: Under high glucose conditions, interleukin-1ß significantly increased expression of c-Jun and decreased the expression of glutamine synthetase. When c-Jun gene was silenced by siRNA, interleukin-1ß could not decrease glutamine synthetase expression in high glucose concentrations. Conclusions: Interleukin-1ß decreases expression of glutamine synthetase via activation of c-Jun. The data suggested that interleukin-1ß may play a role in the development of diabetic retinopathy.