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Roles of Ca(2+)/calmodulin-dependent protein kinase II in subcellular expression of striatal N-methyl-D-aspartate receptors in l-3, 4-dihydroxyphenylalanine-induced dyskinetic rats.

Gan J, Qi C, Liu Z - Drug Des Devel Ther (2015)

Bottom Line: L-DOPA treatment enhanced surface levels of GluN1 expression and reduced its intracellular expression, but did not change total levels of GluN1 protein in the lesioned striatum.In contrast, l-DOPA decreased GluN2A surface expression but increased its intracellular expression.We also found that L-DOPA increased CaMKII autophosphorylation at T286 in striatal neurons.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Xinhua Hospital affiliated to Shanghai Jiao Tong University Medical School, Shanghai, People's Republic of China.

ABSTRACT

Background: The role of N-Methyl-D-aspartate (NMDA) receptors is critical to the development of L-3,4-dihydroxyphenylalanine (L-DOPA)-induced dyskinesia (LID) in Parkinson's disease (PD). Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) is thought to regulate the expression and activation of NMDA receptors in LID, but the interaction between LID and CaMKII-modulated NMDA receptor activity is not clear so far.

Methods: We used 6-hydroxydopamine-lesioned rats to create PD rat model, and at least 21 days of L-DOPA was administrated followed with or without microinjection of CaMKII inhibitor KN-93 into the lesioned striatum of all the PD rats and sham rats. A surface receptor cross-linking assay was used to distinguish expression of striatal NMDA receptors in surface and intracellular compartments.

Results: L-DOPA treatment enhanced surface levels of GluN1 expression and reduced its intracellular expression, but did not change total levels of GluN1 protein in the lesioned striatum. In contrast, l-DOPA decreased GluN2A surface expression but increased its intracellular expression. L-DOPA increased GluN2B expression preferentially in the surface compartment. We also found that L-DOPA increased CaMKII autophosphorylation at T286 in striatal neurons. The inhibition of CaMKII by microinjecting CaMKII inhibitor KN-93 into the lesioned striatum largely reversed the L-DOPA-induced changes in three subunits. In addition, dyskinetic behaviors of animals were observed alleviated after treatment of KN-93.

Conclusion: Our research indicates that long-term L-DOPA administration activates CaMKII in striatal neurons. Activated CaMKII is involved at least in part in mediating L-DOPA-induced changes of NMDA receptors surface/intracellular expression.

No MeSH data available.


Related in: MedlinePlus

Effect of KN-93 on l-DOPA-induced expression of total NMDA receptor subunit proteins in the rat striatum.Notes: Representative immunoblots and Quantification of immunoblots for GluN1 protein (A and B), GluN2A protein (C and D) and GluN2B protein (E and F) in the unlesioned and lesioned side of the striatum in response to l-DOPA in the absence and presence of KN-93. l-DOPA induced an increase in GluN2B levels in the lesioned striatum, while l-DOPA had a minimal impact on GluN1 and GluN2A expression in the either lesioned or unlesioned striatum. Data are expressed in terms of means±SEMs (n=6 per group). *P<0.05 compared with the unlesioned side. +P<0.05 compared with the lesioned side in l-DOPA-treated group.Abbreviations:l-DOPA, l-3,4-dihydroxyphenylalanine; KN-93, N-[2-[[[3-(4-chlorophenyl)-2-propenyl]methylamino]methyl]phenyl]-N-(2-hydroxyethyl)-4-methoxybenze-nesulfonamide; U, un-lesioned; L, lesioned; SEM, standard error of the mean; NMDA, N-Methyl-D-aspartate.
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f3-dddt-9-2119: Effect of KN-93 on l-DOPA-induced expression of total NMDA receptor subunit proteins in the rat striatum.Notes: Representative immunoblots and Quantification of immunoblots for GluN1 protein (A and B), GluN2A protein (C and D) and GluN2B protein (E and F) in the unlesioned and lesioned side of the striatum in response to l-DOPA in the absence and presence of KN-93. l-DOPA induced an increase in GluN2B levels in the lesioned striatum, while l-DOPA had a minimal impact on GluN1 and GluN2A expression in the either lesioned or unlesioned striatum. Data are expressed in terms of means±SEMs (n=6 per group). *P<0.05 compared with the unlesioned side. +P<0.05 compared with the lesioned side in l-DOPA-treated group.Abbreviations:l-DOPA, l-3,4-dihydroxyphenylalanine; KN-93, N-[2-[[[3-(4-chlorophenyl)-2-propenyl]methylamino]methyl]phenyl]-N-(2-hydroxyethyl)-4-methoxybenze-nesulfonamide; U, un-lesioned; L, lesioned; SEM, standard error of the mean; NMDA, N-Methyl-D-aspartate.

Mentions: We then detected the total cellular expression of key NMDA receptor subunits (GluN1, GluN2A, and GluN2B) in striatal neurons of PD rats with l-DOPA+/KN-93 – versus PD rats with l-DOPA+/KN-93+. No significant difference of GluN1 level was found between the lesioned and un-lesioned side of striatum in either l-DOPA+/KN-93 – group or l-DOPA+/KN-93+ group (Figure 3A and 3B). There was no difference between the two sides of striatum in sham rats after treatment with these drugs (Figure 3A and 3B). Similar results were obtained for GluN2A (Figure 3C and 3D). It was noted that the total expression of GluN2B was obviously higher in the lesioned side (152.02%±6.75% of the sham un-lesioned side) than that of the un-lesioned side (120.98%±1.66% of the sham un-lesioned side) in l-DOPA-treated models (P<0.001). KN-93 reduced this elevation of the lesioned side to 124.04%±8.09% of the sham un-lesioned side (P<0.001), while KN-93 caused no alteration in the GluN2B expression in the un-lesioned side of PD rats (121.02%±6.73% of the sham un-lesioned side). As compared to sham animals, GluN2B protein levels in all groups were increased in either lesioned or un-lesioned side (Figure 3E and 3F). Thus, chronic l-DOPA treatment that induces dyskinesia increases GluN2B expression in the striatum, which was reversed by local administration of a CaMKII inhibitor.


Roles of Ca(2+)/calmodulin-dependent protein kinase II in subcellular expression of striatal N-methyl-D-aspartate receptors in l-3, 4-dihydroxyphenylalanine-induced dyskinetic rats.

Gan J, Qi C, Liu Z - Drug Des Devel Ther (2015)

Effect of KN-93 on l-DOPA-induced expression of total NMDA receptor subunit proteins in the rat striatum.Notes: Representative immunoblots and Quantification of immunoblots for GluN1 protein (A and B), GluN2A protein (C and D) and GluN2B protein (E and F) in the unlesioned and lesioned side of the striatum in response to l-DOPA in the absence and presence of KN-93. l-DOPA induced an increase in GluN2B levels in the lesioned striatum, while l-DOPA had a minimal impact on GluN1 and GluN2A expression in the either lesioned or unlesioned striatum. Data are expressed in terms of means±SEMs (n=6 per group). *P<0.05 compared with the unlesioned side. +P<0.05 compared with the lesioned side in l-DOPA-treated group.Abbreviations:l-DOPA, l-3,4-dihydroxyphenylalanine; KN-93, N-[2-[[[3-(4-chlorophenyl)-2-propenyl]methylamino]methyl]phenyl]-N-(2-hydroxyethyl)-4-methoxybenze-nesulfonamide; U, un-lesioned; L, lesioned; SEM, standard error of the mean; NMDA, N-Methyl-D-aspartate.
© Copyright Policy
Related In: Results  -  Collection

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f3-dddt-9-2119: Effect of KN-93 on l-DOPA-induced expression of total NMDA receptor subunit proteins in the rat striatum.Notes: Representative immunoblots and Quantification of immunoblots for GluN1 protein (A and B), GluN2A protein (C and D) and GluN2B protein (E and F) in the unlesioned and lesioned side of the striatum in response to l-DOPA in the absence and presence of KN-93. l-DOPA induced an increase in GluN2B levels in the lesioned striatum, while l-DOPA had a minimal impact on GluN1 and GluN2A expression in the either lesioned or unlesioned striatum. Data are expressed in terms of means±SEMs (n=6 per group). *P<0.05 compared with the unlesioned side. +P<0.05 compared with the lesioned side in l-DOPA-treated group.Abbreviations:l-DOPA, l-3,4-dihydroxyphenylalanine; KN-93, N-[2-[[[3-(4-chlorophenyl)-2-propenyl]methylamino]methyl]phenyl]-N-(2-hydroxyethyl)-4-methoxybenze-nesulfonamide; U, un-lesioned; L, lesioned; SEM, standard error of the mean; NMDA, N-Methyl-D-aspartate.
Mentions: We then detected the total cellular expression of key NMDA receptor subunits (GluN1, GluN2A, and GluN2B) in striatal neurons of PD rats with l-DOPA+/KN-93 – versus PD rats with l-DOPA+/KN-93+. No significant difference of GluN1 level was found between the lesioned and un-lesioned side of striatum in either l-DOPA+/KN-93 – group or l-DOPA+/KN-93+ group (Figure 3A and 3B). There was no difference between the two sides of striatum in sham rats after treatment with these drugs (Figure 3A and 3B). Similar results were obtained for GluN2A (Figure 3C and 3D). It was noted that the total expression of GluN2B was obviously higher in the lesioned side (152.02%±6.75% of the sham un-lesioned side) than that of the un-lesioned side (120.98%±1.66% of the sham un-lesioned side) in l-DOPA-treated models (P<0.001). KN-93 reduced this elevation of the lesioned side to 124.04%±8.09% of the sham un-lesioned side (P<0.001), while KN-93 caused no alteration in the GluN2B expression in the un-lesioned side of PD rats (121.02%±6.73% of the sham un-lesioned side). As compared to sham animals, GluN2B protein levels in all groups were increased in either lesioned or un-lesioned side (Figure 3E and 3F). Thus, chronic l-DOPA treatment that induces dyskinesia increases GluN2B expression in the striatum, which was reversed by local administration of a CaMKII inhibitor.

Bottom Line: L-DOPA treatment enhanced surface levels of GluN1 expression and reduced its intracellular expression, but did not change total levels of GluN1 protein in the lesioned striatum.In contrast, l-DOPA decreased GluN2A surface expression but increased its intracellular expression.We also found that L-DOPA increased CaMKII autophosphorylation at T286 in striatal neurons.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Xinhua Hospital affiliated to Shanghai Jiao Tong University Medical School, Shanghai, People's Republic of China.

ABSTRACT

Background: The role of N-Methyl-D-aspartate (NMDA) receptors is critical to the development of L-3,4-dihydroxyphenylalanine (L-DOPA)-induced dyskinesia (LID) in Parkinson's disease (PD). Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) is thought to regulate the expression and activation of NMDA receptors in LID, but the interaction between LID and CaMKII-modulated NMDA receptor activity is not clear so far.

Methods: We used 6-hydroxydopamine-lesioned rats to create PD rat model, and at least 21 days of L-DOPA was administrated followed with or without microinjection of CaMKII inhibitor KN-93 into the lesioned striatum of all the PD rats and sham rats. A surface receptor cross-linking assay was used to distinguish expression of striatal NMDA receptors in surface and intracellular compartments.

Results: L-DOPA treatment enhanced surface levels of GluN1 expression and reduced its intracellular expression, but did not change total levels of GluN1 protein in the lesioned striatum. In contrast, l-DOPA decreased GluN2A surface expression but increased its intracellular expression. L-DOPA increased GluN2B expression preferentially in the surface compartment. We also found that L-DOPA increased CaMKII autophosphorylation at T286 in striatal neurons. The inhibition of CaMKII by microinjecting CaMKII inhibitor KN-93 into the lesioned striatum largely reversed the L-DOPA-induced changes in three subunits. In addition, dyskinetic behaviors of animals were observed alleviated after treatment of KN-93.

Conclusion: Our research indicates that long-term L-DOPA administration activates CaMKII in striatal neurons. Activated CaMKII is involved at least in part in mediating L-DOPA-induced changes of NMDA receptors surface/intracellular expression.

No MeSH data available.


Related in: MedlinePlus