Purpose: To investigate (1) the role of cytokine interleukin-1beta on 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-1beta under high glucose conditions.
Materials and methods: The effect of interleukin-1beta 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-1beta significantly increased expression of c-Jun and decreased the expression of glutamine synthetase. When c-Jun gene was silenced by siRNA, interleukin-1beta could not decrease glutamine synthetase expression in high glucose concentrations.
Conclusions: Interleukin-1beta decreases expression of glutamine synthetase via activation of c-Jun. The data suggested that interleukin-1beta may play a role in the development of diabetic retinopathy.