Endogenous nitric oxide generation linked to ryanodine receptors activates cyclic GMP / protein kinase G pathway for cell proliferation of neural stem/progenitor cells derived from embryonic hippocampus.
Nitric oxide (NO) activates the cyclic GMP (cGMP) / protein kinase G (PKG) pathway during physiological processes in numerous types of cells. Here, we evaluated whether this NO/cGMP/PKG pathway is involved in the proliferation of neural stem/progenitor cells (NPCs) derived from the hippocampus of embryonic mice. In culture, the exposure to the NO synthase inhibitor N(ω)-nitro-L-arginine methyl ester (L-NAME) significantly decreased the number of viable cells and 5-bromo-2'-deoxyuridine (BrdU) incorporation into the cells, as well as the levels of intracellular reactive oxygen species, extracellular NO(2), and intracellular cGMP. Like L-NAME, the soluble guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) and PKG inhibitor KT5823 also decreased cell viability and BrdU incorporation. The membrane-permeable cGMP analogue 8-bromo-cGMP partially abolished the L-NAME-induced decrease in the BrdU incorporation. BrdU incorporation was decreased by Ca(2+)-channel blockers, including dantrolene, MK-801, ifenprodil, and nifedipine. Interestingly, the NO(2) level was decreased by dantrolene, but not by the other 3 blockers. L-NAME and ODQ attenuated phosphorylation of Akt, but not that of extracellular signal-regulated kinases or epidermal growth factor receptors. Our data suggest that endogenous NO generation linked to dantrolene-sensitive ryanodine receptors activates the cGMP/PKG signaling pathway for positive regulation of proliferation of hippocampal NPCs derived from embryonic mice.
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Osaka 573-0101, Japan.
Masanori
M
Yoneyama
Koichi
K
Kawada
Tatsuo
T
Shiba
Kiyokazu
K
Ogita
D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D017869:Cyclic GMP-Dependent Protein Kinases / Q000378:metabolism*; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects / Q000196:embryology*; D051379:Mice; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D058953:Neural Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D009569:Nitric Oxide / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000032:analysis; D019837:Ryanodine Receptor Calcium Release Channel / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects
D002121:Calcium Channel Blockers; D017382:Reactive Oxygen Species; D019837:Ryanodine Receptor Calcium Release Channel; D009569:Nitric Oxide; D017869:Cyclic GMP-Dependent Protein Kinases; D019331:NG-Nitroarginine Methyl Ester