Autophagy-dependent and -independent involvement of AMP-activated protein kinase in 6-hydroxydopamine toxicity to SH-SY5Y neuroblastoma cells
2012
Autori:
Arsikin-Csordas, KatarinaKravić-Stevović, Tamara
Jovanović, Maja
Ristić, Biljana
Tovilović-Kovačević, Gordana
Zogović, Nevena
Bumbaširević, Vladimir
Trajković, Vladimir
Harhaji-Trajković, Ljubica
Tip dokumenta:
Članak u časopisu (Objavljena verzija)
,
© 2012 Elsevier B.V.
Metapodaci
Prikaz svih podataka o dokumentuApstrakt:
The role of the main intracellular energy sensor adenosine monophosphate (AMP)-activated protein kinase (AMPK) in the induction of autophagic response and cell death was investigated in SH-SY5Y human neuroblastoma cells exposed to the dopaminergic neurotoxin 6-hydroxydopamine (6-OHDA). The induction of autophagy in SH-SY5Y cells was demonstrated by acridine orange staining of intracellular acidic vesicles, the presence of autophagosome- and autophagolysosome-like vesicles confirmed by transmission electron microscopy, as well as by microtubule-associated protein 1 light-chain 3 (LC3) conversion and p62 degradation detected by immunoblotting. 6-OHDA induced phosphorylation of AMPK and its target Raptor, followed by the dephosphorylation of the major autophagy inhibitor mammalian target of rapamycin (mTOR) and its substrate p70S6 kinase (S6K). 6-OHDA treatment failed to suppress mTOR/S6K phosphorylation and to increase LC3 conversion, p62 degradation and cytoplasmatic acidification in neuroblastoma cells in which AMPK expression was downregulated by RNA interference. Transfection of SH-SY5Y cells with AMPK or LC3β shRNA, as well as treatment with pharmacological autophagy inhibitors suppressed, while mTOR inhibitor rapamycin potentiated 6-OHDA-induced oxidative stress and apoptotic cell death. 6-OHDA induced phosphorylation of p38 mitogen-activated protein (MAP) kinase in an AMPK-dependent manner, and pharmacological inhibition of p38 MAP kinase reduced neurotoxicity, but not AMPK activation and autophagy triggered by 6-OHDA. Finally, the antioxidant N-acetyl cysteine antagonized 6-OHDA-induced activation of AMPK, p38 and autophagy. These data suggest that oxidative stress-mediated AMPK/mTOR-dependent autophagy and AMPK/p38-dependent apoptosis could be valid therapeutic targets for neuroprotection.
Izvor:
Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease, 2012, 1822, 11, 1826-1836Finansiranje / projekti:
- Uloga autofagije u regulaciji smrti tumorskih ćelija (RS-MESTD-Basic Research (BR or ON)-173053)
- Modulacija signalnih puteva koji kontrolišu intracelularni energetski balans u terapiji tumora i neuro-imuno-endokrinih poremećaja (RS-MESTD-Integrated and Interdisciplinary Research (IIR or III)-41025)
DOI: 10.1016/j.bbadis.2012.08.006.
ISSN: 0925-4439
PubMed: 22917563