KMUP-1 attenuates serum deprivation-induced neurotoxicity in SH-SY5Y cells: roles of PKG, PI3K/Akt and Bcl-2/Bax pathways.
Aging populations with neurodegenerative disorders will gradually become a greater problem for society. Serum deprivation-induced cell death is recognized as one of the standard models for the study of neurotoxicity. Increasing evidence indicates that cGMP/PKG pathway may play a rescue role in serum deprivation-induced toxicity. The aim of this study was to investigate protective effects of KMUP-1, an enhancer of cGMP/PKG signaling on serum deprivation-induced neurotoxicity in SH-SY5Y neuroblastoma cells. Under normal serum condition, KMUP-1 enhanced protein expression of nNOS, PKG and sGCalpha1, increased intracellular cyclic GMP level, and attenuated PDE5 expression. KMUP-1 also increased expression of BDNF and Bcl-2, but it did not affect Bax expression. The phosphorylation of Akt and CREB induced by KMUP-1 was inhibited by tyrosine kinase (TrK) inhibitor K252a and phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002, respectively. Under serum deprivation condition, flow cytometric analysis using Annexin V showed KMUP-1 increased cell viability, but lacked protective effects in the presence of nitric oxide synthase inhibitor l-NAME, PKG inhibitor Rp-8-pCPT-cGMPS or LY294002. KMUP-1 not only enhanced expression of nNOS, sGCalpha1, PKG, p-CREB, p-Akt and Bcl-2, but also attenuated Bax expression in serum deprivation-treated cultures. In conclusion, cGMP/PKG, PI3K/Akt/CREB and Bcl-2/Bax signals play critical roles in the neuroprotective effects of KMUP-1 on serum deprivation-induced toxicity.
Hsu
Ya-Yun
YY
Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
Liu
Chi-Ming
CM
Tsai
Hsin-Hung
HH
Jong
Yuh-Jyh
YJ
Chen
Ing-Jun
IJ
Lo
Yi-Ching
YC
D015153:Blotting, Western; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism; D045744:Cell Line, Tumor; D016895:Culture Media, Serum-Free; D000242:Cyclic AMP / Q000494:pharmacology; D017869:Cyclic GMP-Dependent Protein Kinases / Q000378:metabolism*; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5 / Q000378:metabolism; D006801:Humans; D009420:Nervous System / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D052248:Nitric Oxide Synthase Type I / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D010880:Piperidines / Q000494:pharmacology*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects; D014970:Xanthines / Q000494:pharmacology*; D051028:bcl-2-Associated X Protein / Q000378:metabolism*
D019208:Brain-Derived Neurotrophic Factor; D016895:Culture Media, Serum-Free; D010880:Piperidines; D014970:Xanthines; D051028:bcl-2-Associated X Protein; C439304:KMUP 1; D009569:Nitric Oxide; D000242:Cyclic AMP; D052248:Nitric Oxide Synthase Type I; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D017869:Cyclic GMP-Dependent Protein Kinases; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5