Time-dependent modulation of mitogen activated protein kinases and AKT in rat hippocampus and cortex in the pilocarpine model of epilepsy

Neurochem Res. 2012 Sep;37(9):1868-78. doi: 10.1007/s11064-012-0797-y. Epub 2012 May 22.

Abstract

The epileptogenesis may involve a variety of signaling events that culminate with synaptic reorganization. Mitogen-activated protein kinases (MAPKs) and AKT may be activated by diverse stimulus including neurotransmitter, oxidative stress, growth factors and cytokines and are involved in synaptic plasticity in the hippocampus and cerebral cortex. The pilocarpine model in rodents reproduces the main features of mesial temporal lobe epilepsy related to hippocampus sclerosis (MTLE-HS) in humans. We analyze the phosphorylation profile of MAPKs (ERK1/2, p38(MAPK), JNK1/2/3) and AKT by western blotting in the hippocampus (Hip) and cortex (Ctx) of male adult wistar rats in different periods, after pilocarpine induced status epilepticus (Pilo-SE) and compared with control animals. Biochemical analysis were done in the Hip and Ctx at 1, 3, 12 h (acute period), 5 days (latent period) and 50 days (chronic period) after Pilo-SE onset. Hence, the main findings include increased phosphorylation of ERK1 and p38(MAPK) in the Hip and Ctx 1 and 12 h after the Pilo-SE onset. The JNK2/3 isoform (54 kDa) phosphorylation was decreased at 3 h after the Pilo-SE onset and in the chronic period in the Hip and Ctx. The AKT phosphorylation increased only in the Hip during the latent period. Our study demonstrates, in a systematic manner, the profile of MAPKs and AKT modulation in the hippocampus and cerebral cortex in response to pilocarpine. Based in the role of each signaling enzyme is possible that these changes may be related, at least partially, to modifications in the intrinsic neuronal physiology and epileptogenic synaptic network that appears in the MTLE-HS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • Cerebral Cortex / metabolism*
  • Epilepsy / chemically induced*
  • Epilepsy / enzymology
  • Epilepsy / metabolism*
  • Hippocampus / metabolism*
  • MAP Kinase Signaling System / drug effects
  • Male
  • Mitogen-Activated Protein Kinase 10 / metabolism
  • Mitogen-Activated Protein Kinase 8 / metabolism
  • Mitogen-Activated Protein Kinase 9 / metabolism
  • Mitogen-Activated Protein Kinases / metabolism*
  • Muscarinic Agonists*
  • Oncogene Protein v-akt / metabolism*
  • Pilocarpine*
  • Rats
  • Rats, Wistar
  • Status Epilepticus / chemically induced
  • Status Epilepticus / enzymology
  • Status Epilepticus / metabolism
  • p38 Mitogen-Activated Protein Kinases / metabolism

Substances

  • Muscarinic Agonists
  • Pilocarpine
  • Mitogen-Activated Protein Kinase 10
  • Mitogen-Activated Protein Kinase 9
  • Oncogene Protein v-akt
  • Mitogen-Activated Protein Kinase 8
  • Mitogen-Activated Protein Kinases
  • p38 Mitogen-Activated Protein Kinases