title: Phosphodiesterase-2 inhibitor reverses corticosterone-induced neurotoxicity and related behavioural changes via cGMP/PKG dependent pathway.
abstract: Phosphodiesterase 2 (PDE2) is an enzyme responsible for hydrolysis of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) to restrict intracellular signalling of these second messenger molecules. This study investigated how PDE2 inhibitor Bay 60-7550 affects the dysregulated glucocorticoid signalling in neuronal cells and regulates depressive behaviours after chronic stress in mice. We found that exposure of hippocampal neurons to corticosterone resulted in time- and concentration-dependent increases in PDE2 expression. These intriguing findings were confirmed in the hippocampal cell line HT-22. After corticosterone exposure for 24 h, HT-22 cells showed a concentration-dependent increase in mRNA levels for PDE2 subtypes, PDE2A1 and 2A3, as well as for the total PDE2A protein expression. Bay 60-7550 was found to reverse the cell lesion induced by corticosterone (50 μm). This neuroprotective effect was blocked by pretreatment with protein kinase G inhibitor KT5823, but not protein kinase A inhibitor H89, suggesting the involvement of cGMP-dependent signalling. Although Bay 60-7550 treatment for 24 h did not change the levels of phosphorylated mitogen-activated protein kinases ERK1/2 (pERK) and phosphorylated cAMP response element-binding protein (pCREB), it down-regulated pERK at 2 h and up-regulated a CREB co-activator, CREB-binding protein, at 24 h. Both of these effects were blocked by KT 5823. Furthermore, Bay 60-7550 reversed corticosterone-induced down-regulation of brain-derived neurotrophic factor protein levels 24 h after corticosterone exposure. In behavioural testing, Bay 60-7550 produced antidepressant-like effects and reduced corticosterone levels in stressed mice, further supporting the involvement of a PDE2-dependent pathway in mediating Bay 60-7550's effect during stress hormone insults.
authors: Department of Behavioral Medicine and Psychiatry, West Virginia University, Morgantown, WV 26505, USA. ygxu@hsc.wvu.edu
authors: Ying
authors: Y
authors: Xu
authors: Jianchun
authors: J
authors: Pan
authors: Ling
authors: L
authors: Chen
authors: Chong
authors: C
authors: Zhang
authors: Jiao
authors: J
authors: Sun
authors: Jianxin
authors: J
authors: Li
authors: Linda
authors: L
authors: Nguyen
authors: Neetu
authors: N
authors: Nair
authors: Hanting
authors: H
authors: Zhang
authors: James M
authors: JM
authors: O'Donnell
mesh_terms: D000818:Animals; D002227:Carbazoles / Q000494:pharmacology; D002478:Cells, Cultured; D003345:Corticosterone / Q000633:toxicity*; D006152:Cyclic GMP / Q000037:antagonists & inhibitors / Q000378:metabolism; D017869:Cyclic GMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D054678:Cyclic Nucleotide Phosphodiesterases, Type 2 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005260:Female; D006624:Hippocampus / Q000187:drug effects / Q000201:enzymology; D007093:Imidazoles / Q000494:pharmacology / Q000627:therapeutic use; D008297:Male; D051379:Mice; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D011247:Pregnancy; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D013315:Stress, Psychological / Q000139:chemically induced / Q000188:drug therapy / Q000201:enzymology; D014227:Triazines / Q000494:pharmacology / Q000627:therapeutic use
chemical_list: C539142:2-(3,4-dimethoxybenzyl)-7-(1-(1-hydroxyethyl)-4-phenylbutyl)-5-methylimidazo(5,1-f)(1,2,4)triazin-4 (3H)-one; D002227:Carbazoles; D007093:Imidazoles; D010726:Phosphodiesterase Inhibitors; D047428:Protein Kinase Inhibitors; D014227:Triazines; C073601:KT 5823; D017869:Cyclic GMP-Dependent Protein Kinases; D054678:Cyclic Nucleotide Phosphodiesterases, Type 2; D006152:Cyclic GMP; D003345:Corticosterone