An analog of a dipeptide-like structure of FK506 increases glial cell line-derived neurotrophic factor expression through cAMP response element-binding protein activated by heat shock protein 90/Akt signaling pathway.
Glial cell line-derived neurotrophic factor (GDNF) is an important neurotrophic factor that has therapeutic implications for neurodegenerative disorders. We previously showed that leucine-isoleucine (Leu-Ile), an analog of a dipeptide-like structure of FK506 (tacrolimus), induces GDNF expression both in vivo and in vitro. In this investigation, we sought to clarify the cellular mechanisms underlying the GDNF-inducing effect of this dipeptide. Leu-Ile transport was investigated using fluorescein isothiocyanate-Leu-Ile in cultured neurons, and the results showed the transmembrane mobility of this dipeptide. By liquid chromatography-mass spectrometry and quartz crystal microbalance assay, we identified heat shock cognate protein 70 as a protein binding specifically to Leu-Ile, and molecular modeling showed that the ATPase domain is the predicted binding site. Leu-Ile stimulated Akt phosphorylation, which was attenuated significantly by heat shock protein 90 (Hsp90) inhibitor geldanamycin (GA). Moreover, enhanced interaction between phosphorylated Akt and Hsp90 was detected by immunoprecipitation. Leu-Ile elicited an increase in cAMP response element binding protein (CREB) phosphorylation, which was inhibited by GA, indicating that CREB is a downstream target of Hsp90/Akt signaling. Leu-Ile elevated the levels of GDNF mRNA and protein expression, whereas inhibition of CREB blocked such effects. Leu-Ile promoted the binding activity of phosphorylated CREB with cAMP response element. These findings show that CREB plays a key role in transcriptional regulation of GDNF expression induced by Leu-Ile. In conclusion, Leu-Ile activates Hsp90/Akt/CREB signaling, which contributes to the upregulation of GDNF expression. It may represent a novel lead compound for the treatment of dopaminergic neurons or motoneuron diseases.
Cen
Xiaobo
X
Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University Graduate School of Medicine, Nagoya 466-8560, Japan.
Nitta
Atsumi
A
Ohya
Shin
S
Zhao
Yinglan
Y
Ozawa
Naoya
N
Mouri
Akihiro
A
Ibi
Daisuke
D
Wang
Li
L
Suzuki
Makiko
M
Saito
Kuniaki
K
Ito
Yasutomo
Y
Kawagoe
Tetsuya
T
Noda
Yukihiro
Y
Ito
Yoshihisa
Y
Furukawa
Shoei
S
Nabeshima
Toshitaka
T
D000818:Animals; D001665:Binding Sites / Q000502:physiology; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D017362:Cyclic AMP Response Element-Binding Protein / Q000187:drug effects / Q000378:metabolism*; D004151:Dipeptides / Q000737:chemistry / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D051100:Glial Cell Line-Derived Neurotrophic Factor / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D050883:HSC70 Heat-Shock Proteins / Q000378:metabolism; D018841:HSP90 Heat-Shock Proteins / Q000187:drug effects / Q000378:metabolism*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011485:Protein Binding / Q000502:physiology; D051057:Proto-Oncogene Proteins c-akt / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D016559:Tacrolimus / Q000031:analogs & derivatives* / Q000737:chemistry; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology
D017362:Cyclic AMP Response Element-Binding Protein; D004151:Dipeptides; D004791:Enzyme Inhibitors; D051100:Glial Cell Line-Derived Neurotrophic Factor; D050883:HSC70 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; D012333:RNA, Messenger; C492946:leucyl-isoleucyl; D051057:Proto-Oncogene Proteins c-akt; D016559:Tacrolimus