Involvement of cAMP in nerve growth factor-triggered p35/Cdk5 activation and differentiation in PC12 cells

Mei Chih Chen, Ho Lin, Fu Ning Hsu, Pao Hsuan Huang, Guan Shun Lee, Paulus S. Wang

Research output: Contribution to journalArticle

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Abstract

The signaling mechanisms underlying cell differentiation have been extensively studied with the use of rat PC12 cells as a model system. Nerve growth factor (NGF) is a trophic factor inducing PC12 cell differentiation through the activation of the p35/cyclin-dependent kinase 5 (Cdk5) complex. It has been reported that adenylyl cyclase activation and cAMP production may be involved in NGF-dependent actions. Our previous results indicate that cAMP activates the p35/Cdk5 complex in reproductive cells. Therefore, the role of cAMP in NGF-triggered p35/Cdk5 activation and PC12 differentiation was interesting to explore. Our results indicate that roscovitine, a molecular inhibitor of Cdk5, blocks cAMP-triggered PC12 differentiation, which was evaluated by neurite initiation, a decrease in proliferation, and cell cycle G1 arrest. The following data show that cAMP treatment increased Cdk5 activity through p35 upregulation. cAMP downstream components, protein kinase A (PKA) and phosphorylated cAMP response element binding protein (CREB), are involved in this regulation. The immunocyto-chemical results indicate that PKA inhibition disrupted cAMP-triggered p35/Cdk5 localization in PC12 cells. In addition, adenylyl cyclase inhibition was found to diminish NGF-induced intracellular cAMP production, CREB phosphorylation, and p35 expression. The cAMP antagonist and the PKA inhibitors reduced NGF-induced p35 expression. Finally, NGF-triggered PC12 differentiation was partially decreased by adenylyl cyclase or PKA inhibitors. In conclusion, these results demonstrate that cAMP may play a role in NGF-p35/Cdk5-dependent PC12 differentiation.

Original languageEnglish (US)
Pages (from-to)C516-C527
JournalAmerican Journal of Physiology - Cell Physiology
Volume299
Issue number2
DOIs
StatePublished - Aug 1 2010

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Keywords

  • Adenosine 3′,5′-cyclic monophosphate
  • Cyclindependent kinase 5
  • Nerve growth factor

ASJC Scopus subject areas

  • Physiology
  • Cell Biology

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