Abstract
Purpose: :
The goal of this study was to investigate whether centrifugal force induced changes in expression of glutamate transporters (GLTs) of isolated Muller cells either in mRNA- or protein levels.
Methods: :
Primary cultured retinal Muller cells from 3-day-old Sprague-Dawley rats were exposed 40mmHg of centrifugal force for 6, 12, 24, 48, and 72 hrs, respectively. As a control, Muller cells from an identical passage were incubated simultaneously in the same incubator without centrifugal force loading. The mRNA levels of GLTs were measured by quantitative real-time PCR analysis. GLAST protein in Muller cells was immunostained and quantified using Image J program (NIH).
Results: :
The expression level of GLAST mRNA changed as a result of exposure time to centrifugal force loading. GLAST mRNAs in experimented Muller cells were increased by 1.24 folds for 12 hours and 1.47folds for 24 hrs, respectively (p<0.05), and then declined to the baseline after 2 days. GLAST proteins were significantly increased by 28.53% and 27.92% after 30 hrs or 72 hrs, respectively (p<0.05). In contrast, GLT-1 mRNA did not show any significant change by the current loading.
Conclusions: :
Centrifugal force pressure changes expression of GLT, but this modification is different among subtypes of GLTs. The current results suggest that GLAST may play a major role in glutamate metabolism of Muller cells under the centrifugal force pressure condition.