Induction of neurite outgrowth in PC12 cells treated with temperature-controlled repeated thermal stimulation

PLoS One. 2015 Apr 16;10(4):e0124024. doi: 10.1371/journal.pone.0124024. eCollection 2015.

Abstract

To promote the functional restoration of the nervous system following injury, it is necessary to provide optimal extracellular signals that can induce neuronal regenerative activities, particularly neurite formation. This study aimed to examine the regulation of neuritogenesis by temperature-controlled repeated thermal stimulation (TRTS) in rat PC12 pheochromocytoma cells, which can be induced by neurotrophic factors to differentiate into neuron-like cells with elongated neurites. A heating plate was used to apply thermal stimulation, and the correlation of culture medium temperature with varying surface temperature of the heating plate was monitored. Plated PC12 cells were exposed to TRTS at two different temperatures via heating plate (preset surface temperature of the heating plate, 39.5°C or 42°C) in growth or differentiating medium for up to 18 h per day. We then measured the extent of growth, neuritogenesis, or acetylcholine esterase (AChE) activity (a neuronal marker). To analyze the mechanisms underlying the effects of TRTS on these cells, we examined changes in intracellular signaling using the following: tropomyosin-related kinase A inhibitor GW441756; p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580; and MAPK/extracellular signal-regulated kinase (ERK) kinase (MEK) inhibitor U0126 with its inactive analog, U0124, as a control. While a TRTS of 39.5°C did not decrease the growth rate of cells in the cell growth assay, it did increase the number of neurite-bearing PC12 cells and AChE activity without the addition of other neuritogenesis inducers. Furthermore, U0126, and SB203580, but not U0124 and GW441756, considerably inhibited TRTS-induced neuritogenesis. These results suggest that TRTS can induce neuritogenesis and that participation of both the ERK1/2 and p38 MAPK signaling pathways is required for TRTS-dependent neuritogenesis in PC12 cells. Thus, TRTS may be an effective technique for regenerative neuromedicine.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcholinesterase / metabolism
  • Animals
  • Butadienes / pharmacology
  • Cell Differentiation / drug effects
  • Chromaffin Cells / cytology
  • Chromaffin Cells / metabolism
  • Imidazoles / pharmacology
  • Indoles / pharmacology*
  • Neurites / metabolism*
  • Neurogenesis / drug effects
  • Neurons / cytology*
  • Neurons / metabolism
  • Nitriles / pharmacology
  • PC12 Cells
  • Protein Kinase Inhibitors / pharmacology
  • Pyridines / pharmacology
  • Rats
  • Receptor, trkA / antagonists & inhibitors
  • Signal Transduction / drug effects
  • Temperature*

Substances

  • Butadienes
  • GW 441756
  • Imidazoles
  • Indoles
  • Nitriles
  • Protein Kinase Inhibitors
  • Pyridines
  • U 0126
  • Receptor, trkA
  • Acetylcholinesterase
  • SB 203580

Grants and funding

This work was supported in part by the Japan Society for the Promotion of Science (www.jsps.go.jp) KAKENHI grant number 25861880, and by the Cooperative Research Project of Joint Usage/Research Center at the Institute of Development, Aging, and Cancer, Tohoku University (www.idac.tohoku.ac.jp). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.