Schwann cells protect against CaMKII- and PKA-dependent Acrylamide-induced Synapsin I phosphorylation

Brain Res. 2018 Dec 15:1701:18-27. doi: 10.1016/j.brainres.2018.07.019. Epub 2018 Jul 17.

Abstract

Objectives: To explore the effects of Acrylamide (ACR), as well as the influence of Schwann cells (SCs), on the signal transduction pathway and phosphorylation of Synapsin I in a Human neuroblastoma cell line (NB-1).

Methods: NB-1s, NB-1s co-cultured with SCs, and a negative control group (NB-1 cells without ACR) were exposed to gradient concentrations of ACR for 48 h. Cell proliferation and viability were determined by MTT. Protein and mRNA expression levels of typical kinases (i.e., cAMP-dependent protein kinase [PKA], calcium/calmodulin-dependent protein kinase II [CaMKII], and mitogen-activated protein kinase-extracellular signal-regulated kinases [MAPK-Erk]), their phosphorylation status, as well as Synapsin I and its phosphorylation status, were tested by western blotting and polymerase chain reaction, respectively. Further, the effect of SCs on ACR-induced NB-1 cell toxicity was evaluated.

Results: (1) The MTT assay showed a sustained, dose- and time-dependent inhibition of NB-1s exposed to ACR. (2) ACR exposure increased the phosphorylation of CaMKII and PKA, which subsequently increased the phosphorylation of Synapsin I (at Serine603 [a substrate site of CaMKII] and Serine9 [a substrate site of PKA]). Pretreatment with CaMKII and PKA inhibitors blocked the ACR-mediated increase in phosphorylation. The above-described results were all significantly different when compared to the control group (p < 0.05). (3) When co-cultured with SCs, ACR-induced NB-1 inhibition was obviously decreased, and the trend of change of phosphorylated CaMKII, PKA, and Synapsin I were changed (first slightly increased and then decreased), which was inconsistent with what we observed in NB-1s cultured alone.

Conclusions: The toxic effects of ACR on neurons may be mediated by CaMKII and PKA-dependent signaling pathways in which Synapsin I may act as a downstream effector. Furthermore, glial cells (SCs) may be able to prevent a certain degree of ACR-induced neuronal damage.

Keywords: Acrylamide; CaMKII; MAPK-Erk; PKA; Synapsin I.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acrylamide / adverse effects
  • Acrylamide / pharmacology
  • Animals
  • Calcium-Calmodulin-Dependent Protein Kinase Type 2 / metabolism
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Cells, Cultured
  • Cyclic AMP-Dependent Protein Kinases / metabolism
  • Extracellular Signal-Regulated MAP Kinases / metabolism
  • Humans
  • Neuroblastoma / metabolism
  • Neuroglia / metabolism
  • Neurons / drug effects
  • Neurons / metabolism
  • Phosphorylation / drug effects
  • Primary Cell Culture
  • Protective Agents / pharmacology
  • Protein Kinase Inhibitors / pharmacology
  • Rats
  • Rats, Sprague-Dawley
  • Schwann Cells / drug effects*
  • Schwann Cells / metabolism*
  • Serine / metabolism
  • Signal Transduction / drug effects
  • Synapsins / metabolism*

Substances

  • Protective Agents
  • Protein Kinase Inhibitors
  • Synapsins
  • Acrylamide
  • Serine
  • Cyclic AMP-Dependent Protein Kinases
  • Calcium-Calmodulin-Dependent Protein Kinase Type 2
  • Extracellular Signal-Regulated MAP Kinases