METHODS: After kainate (KA) injection in wild-type, PLPP/CIN-/- and PLPP/CINTg mice, seizure susceptibility, PAK1 S204 autophosphorylation, nuclear factor-κB (NF-κB) p65 S276 phosphorylation, cyclooxygenase-2 (COX-2) upregulation, prostaglandin E synthase 2 (PTGES2) induction and neuronal damage were measured. The effects of 1,1\'-dithiodi-2-naphthtol (IPA-3, a selective inhibitor of PAK1) pretreatment on these responses to KA were also validated.
RESULTS: PLPP/CIN overexpression increased PAK1 S204 autophosphorylation concomitant with the enhanced NF2 S10 dephosphorylation in hippocampal neurons under physiological condition. Following KA treatment, PLPP/CIN overexpression delayed the seizure on-set and accelerated PAK1 S204 phosphorylation, NF-κB p65 S276 phosphorylation, COX-2 upregulation and PTGES2 induction, which were ameliorated by PLPP/CIN deletion or IPA-3. Furthermore, IPA-3 pretreatment shortened the latency of seizure on-set without affecting seizure severity (intensity) and ameliorated CA3 neuronal death induced by KA.
CONCLUSIONS: These findings indicate that PLPP/CIN may regulate seizure susceptibility (the latency of seizure on-set) and CA3 neuronal death in response to KA through NF2-PAK1-NF-κB-COX-2-PTGES2 signaling pathway.
方法:野生型红藻氨酸(KA)注射后,PLPP/CIN-/-和PLPP/CINTg小鼠,癫痫发作易感性,PAK1S204自磷酸化,核因子-κB(NF-κB)p65S276磷酸化,环氧合酶-2(COX-2)上调,测量前列腺素E合酶2(PTGES2)的诱导和神经元损伤。还验证了1,1'-二硫代-2-萘酚(IPA-3,PAK1的选择性抑制剂)预处理对这些对KA的反应的影响。
结果:在生理条件下,PLPP/CIN过表达增加了PAK1S204自磷酸化,同时增强了NF2S10去磷酸化。KA治疗后,PLPP/CIN过表达延迟癫痫发作并加速PAK1S204磷酸化,NF-κBp65S276磷酸化,COX-2上调和PTGES2诱导,通过PLPP/CIN缺失或IPA-3改善。此外,IPA-3预处理在不影响癫痫发作严重程度(强度)的情况下缩短了癫痫发作的潜伏期,并改善了KA诱导的CA3神经元死亡。
结论:这些研究结果表明,PLPP/CIN可能通过NF2-PAK1-NF-κB-COX-2-PTGES2信号通路调节对KA的癫痫易感性(癫痫发作潜伏期)和CA3神经元死亡。