Voltage-gated K+ channels play a role in cAMP-stimulated neuritogenesis in mouse neuroblastoma N2A cells

• Published in: Journal of cellular physiology 2011-04, Vol.226 (4), p.1090-1098
• Main Authors: Leung, Yuk-Man, Huang, Chien-Fang, Chao, Chia-Chia, Lu, Dah-Yuu, Kuo, Chang-Shin, Cheng, Tzu-Hurng, Chang, Li-Yun, Chou, Chun-Hsiao
• Format: Article
• Language: English
• Subjects: 1-Methyl-3-isobutylxanthine - pharmacology; Animals; Calcium Channels - metabolism; Cell Differentiation - drug effects; Cell Line, Tumor; Colforsin - pharmacology; Cyclic AMP - pharmacology; Cyclic AMP-Dependent Protein Kinases - antagonists & inhibitors; Cyclic AMP-Dependent Protein Kinases - metabolism; Gene Silencing - drug effects; Intracellular Space - drug effects; Intracellular Space - metabolism; Ion Channel Gating - drug effects; Mice; Neurites - drug effects; Neurites - metabolism; Neuroblastoma - metabolism; Neurogenesis - drug effects; Potassium Channel Blockers - pharmacology; Potassium Channels, Voltage-Gated - metabolism; Protein Kinase Inhibitors - pharmacology; Sodium Channels - metabolism; Valinomycin - pharmacology
• ISSN: 0021-9541; 1097-4652
• DOI: 10.1002/jcp.22430

Neuritogenesis is essential in establishing the neuronal circuitry. An important intracellular signal causing neuritogenesis is cAMP. In this report, we showed that an increase in intracellular cAMP stimulated neuritogenesis in neuroblastoma N2A cells via a PKA‐dependent pathway. Two voltage‐gated K+ (Kv) channel blockers, 4‐aminopyridine (4‐AP) and tetraethylammonium (TEA), inhibited cAMP‐stimulated neuritogenesis in N2A cells in a concentration‐dependent manner that remarkably matched their ability to inhibit Kv currents in these cells. Consistently, siRNA knock down of Kv1.1, Kv1.4, and Kv2.1 expression reduced Kv currents and inhibited cAMP‐stimulated neuritogenesis. Kv1.1, Kv1.4, and Kv2.1 channels were expressed in the cell bodies and neurites as shown by immunohistochemistry. Microfluorimetric imaging of intracellular [K+] demonstrated that [K+] in neurites was lower than that in the cell body. We also showed that cAMP‐stimulated neuritogenesis may not involve voltage‐gated Ca2+ or Na+ channels. Taken together, the results suggest a role of Kv channels and enhanced K+ efflux in cAMP/PKA‐stimulated neuritogenesis in N2A cells. J. Cell. Physiol. 226: 1090–1098, 2011. © 2010 Wiley‐Liss, Inc.