SURGICAL INCISION INDUCES PHOSPHORYLATION OF AMPA RECEPTOR GLUR1 SUBUNITS AT SERINE-831 SITES AND GLUR1 TRAFFICKING IN SPINAL CORD DORSAL HORN VIA A PROTEIN KINASE Cy-DEPENDENT MECHANISM

摘要

Spinal alpha-amino-3-hydroxy-5-methy-4-isoxazole propionate (AMPA) receptor plays an important role in acute pain induced by surgical tissue injuries. Our previous study has shown that the enhanced phosphorylation of AMPA receptor GluR1 subunits at Serine-831 sites by protein kinase C (PKC) in the spinal cord dorsal horn is involved in post-surgical pain hypersensitivity. However, which iso-forms of PKC are responsible for the phosphorylation of AMPA receptor GluR1 subunits at Serine-831 sites remains to be established. In the present study, using an animal model of postoperative pain, we found that surgical tissue injuries enhanced the membrane translocation level of PKCgamma, but not PKCalpha, betaI, and pII, and induced the trafficking of GluR1, but not GluR2 into neuronal plasma membrane. Intrathecal (i.t.) pretreatment of small interfering RNA targeting PKCy to reduce the PKCy expression in the spinal cord significantly attenuated the pain hypersensitivity and inhibited the phosphorylation of AMPA receptor GluR1 subunits at Serine-831 sites as well as GluR1 membrane trafficking. Our study indicates that the surgical incision-induced phosphorylation of AMPA receptor GluR1 subunits at Serine-831 sites and GluR1 trafficking are regulated by a PKCy-depen-dent mechanism.