TY - JOUR
T1 - Protein kinase C-mediated modulation of glutamate transporter activity in rat retina
AU - Bull, Natalie D.
AU - Wood, John P.
AU - Osborne, Neville N.
AU - Barnett, Nigel L.
PY - 2007/2/1
Y1 - 2007/2/1
N2 - It has previously been shown that inhibitors of protein kinase C (PKC) attenuate retinal glutamate uptake in situ. The aim of the current study was to determine whether PKCδ -mediated inhibition differentially reduces the transport of glutamate into retinal Müller cells when compared with retinal neurons. The influence of two different types of PKC inhibitors on the uptake of [3H]D-aspartate was therefore compared in the intact retina, mixed retinal cultures, and Müller cell-enriched retinal cultures. It was found that 25 μM of the pan-isoform PKC inhibitor, chelerythrine, reduced [3H]D-aspartate uptake by 78%, 71%, and 68% in isolated retinas, mixed neuronal/glial cultures, and Müller cell-enriched cultures, respectively. Importantly, 20 μM of the PKCδ -selective inhibitor rottlerin also reduced the uptake of D-aspartate to similar extents in all three systems, and the reductions were statistically similar to those found for the pan-specific PKC inhibitor. Neither pan-isoform nor PKCδ -selective activators stimulated glutamate uptake in either culture system or the intact retina. The current results suggest that specific PKC inhibitors are quantitatively similar in reducing the uptake of glutamate into retinal neurons and Müller cells.
AB - It has previously been shown that inhibitors of protein kinase C (PKC) attenuate retinal glutamate uptake in situ. The aim of the current study was to determine whether PKCδ -mediated inhibition differentially reduces the transport of glutamate into retinal Müller cells when compared with retinal neurons. The influence of two different types of PKC inhibitors on the uptake of [3H]D-aspartate was therefore compared in the intact retina, mixed retinal cultures, and Müller cell-enriched retinal cultures. It was found that 25 μM of the pan-isoform PKC inhibitor, chelerythrine, reduced [3H]D-aspartate uptake by 78%, 71%, and 68% in isolated retinas, mixed neuronal/glial cultures, and Müller cell-enriched cultures, respectively. Importantly, 20 μM of the PKCδ -selective inhibitor rottlerin also reduced the uptake of D-aspartate to similar extents in all three systems, and the reductions were statistically similar to those found for the pan-specific PKC inhibitor. Neither pan-isoform nor PKCδ -selective activators stimulated glutamate uptake in either culture system or the intact retina. The current results suggest that specific PKC inhibitors are quantitatively similar in reducing the uptake of glutamate into retinal neurons and Müller cells.
UR - http://www.scopus.com/inward/record.url?scp=33847289185&partnerID=8YFLogxK
U2 - 10.1080/02713680601139200
DO - 10.1080/02713680601139200
M3 - Article
C2 - 17364745
AN - SCOPUS:33847289185
SN - 0271-3683
VL - 32
SP - 123
EP - 131
JO - Current Eye Research
JF - Current Eye Research
IS - 2
ER -