Staurosporine induces dopaminergic neurite outgrowth through AMP-activated protein kinase/mammalian target of rapamycin signaling pathway.
Axonal degeneration of dopaminergic neurons is one of the pathological features in the early stages of Parkinson disease. Promotion of axonal outgrowth of the remaining dopaminergic neurons leads to the recovery of the nigrostriatal pathway. Staurosporine (STS), a wide-spectrum kinase inhibitor, induces neurite outgrowth in various cell types, although its mechanism of action remains elusive. In this study, we analyzed which protein kinase is involved in STS-induced neurite outgrowth. We have previously established the method to measure the length of dopaminergic neurites that extend from a mesencephalic cell region, which is formed on a coverslip by an isolation wall. By means of this method, we clarified that STS treatment causes dopaminergic axonal outgrowth in mesencephalic primary cultures. Among the specific protein kinase inhibitors we tested, compound C (C.C), an AMP-activated protein kinase (AMPK) inhibitor, promoted dopaminergic neurite outgrowth. STS as well as C.C elevated the phosphorylation level of 70-kDa ribosomal protein S6 kinase, a downstream target of mammalian target of rapamycin (mTOR) signaling pathway. The STS- and C.C-induced dopaminergic neurite outgrowth was suppressed by rapamycin, an mTOR inhibitor. Furthermore, the application of C.C rescued 1-methyl-4-phenylpyridinium ion (MPP(+))-induced dopaminergic neurite degeneration. These results suggest that STS induces dopaminergic axonal outgrowth through mTOR signaling pathway activation as a consequence of AMPK inhibition.
Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan. Electronic address: wakita.seiko.88c@st.kyoto-u.ac.jp.
Seiko
S
Wakita
Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan. Electronic address: yizumi@pharm.kyoto-u.ac.jp.
Yasuhiko
Y
Izumi
Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan. Electronic address: nakai.toshie.87w@st.kyoto-u.ac.jp.
Toshie
T
Nakai
Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan. Electronic address: adachi.kanami.26v@st.kyoto-u.ac.jp.
Kanami
K
Adachi
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Doshisha Women's College, 97-1 Minamihokodate, Kodo, Kyotanabe, Kyoto 610-0395, Japan. Electronic address: ytakator@dwc.doshisha.ac.jp.
Yuki
Y
Takada-Takatori
Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan. Electronic address: tkume@pharm.kyoto-u.ac.jp.
Toshiaki
T
Kume
Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan; Graduate School of Pharmaceutical Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan. Electronic address: aakaike@pharm.kyoto-u.ac.jp.
Akinori
A
Akaike
D055372:AMP-Activated Protein Kinases / Q000378:metabolism*; D000818:Animals; D059290:Dopaminergic Neurons / Q000187:drug effects* / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D016501:Neurites / Q000187:drug effects* / Q000378:metabolism; D055495:Neurogenesis / Q000187:drug effects; D016716:PC12 Cells; D010766:Phosphorylation / Q000187:drug effects; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects; D019311:Staurosporine / Q000494:pharmacology*; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism*
D004791:Enzyme Inhibitors; D058570:TOR Serine-Threonine Kinases; D055372:AMP-Activated Protein Kinases; D019311:Staurosporine
1-Methyl-4-phenylpyridinium ion; 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine; 70-kDa Ribosomal protein S6 kinase; AMP-activated protein kinase; AMPK; C.C; CRMP2; DAB; DIV; DMEM; Dopaminergic neuron; Dulbecco's modified Eagle medium; EMEM; Eagle's minimum essential medium; FCS; HS; JNK; MAP2; MPP(+); MPTP; Mammalian target of rapamycin; Neurite outgrowth; PD; Parkinson disease; STS; Staurosporine; TH; TMRM; c-Jun NH2-terminal kinase; collapsing response mediator protein 2; compound C; days in vitro; diaminobenzidine; fetal calf serum; horse serum; mTOR; mammalian target of rapamycin; microtubule associated protein 2; p70S6K; pNF; phosphorylated neurofilaments; staurosporine; tetramethylrhodamine methyl ester; tyrosine hydroxylase