Growth factors protect PC12 cells against ischemia by a mechanism that is independent of PKA, PKC, and protein synthesis. Academic Article uri icon

Overview

abstract

  • We have established an in vitro model of ischemia incorporating the combination of anoxia with glucose deprivation, which is toxic to PC12 cells. In this model, nerve growth factor (NGF), basic fibroblast growth factor (bFGF), and epidermal growth factor (EGF) improve PC12 cell survival. K252a, a specific inhibitor of NGF-induced trk p140 autophosphorylation, did not alter the neuroprotection provided by EGF or bFGF, yet it completely abolished the protection provided by NGF. Activation of protein kinase A (PKA) with dibutyryl-cAMP also protected during ischemia, although it was not additive with the effect provided by growth factors. Furthermore, growth factors protected a PKA-deficient mutant as effectively as the parental cell line; thus, activation of PKA is protective against ischemia but is not necessary for the action of peptide growth factors. Neither the stimulation of protein kinase C (PKC) with acute phorbol ester treatment nor the downregulation of PKC with chronic high-dose phorbol ester treatment resulted in an altered response to growth factors in either the PC12 wild type or PKA-deficient mutant. Thus, protection by peptide growth factors depends on neither PKA nor PKC. Furthermore, downregulation of PKC alone was protective, indicating that PKC may contribute to toxicity. Interestingly, treatment with the kinase inhibitor H-7 was neuroprotective and may have enhanced the neuroprotective effect of NGF. In contrast, staurosporine, a broadly acting kinase inhibitor, inhibited the neuroprotective effect of NGF, but not of EGF or FGF.(ABSTRACT TRUNCATED AT 250 WORDS)

publication date

  • October 1, 1993

Research

keywords

  • Cell Survival
  • Cyclic AMP-Dependent Protein Kinases
  • Epidermal Growth Factor
  • Fibroblast Growth Factor 2
  • Ischemia
  • Neoplasm Proteins
  • Nerve Growth Factors
  • Protein Kinase C

Identity

PubMed Central ID

  • PMC6576367

Scopus Document Identifier

  • 0027369394

Digital Object Identifier (DOI)

  • 10.1523/JNEUROSCI.13-10-04220.1993

PubMed ID

  • 8410184

Additional Document Info

volume

  • 13

issue

  • 10