MPP+-induced cytotoxicity in neuroblastoma cells: Antagonism and reversal by guanosine

Purinergic Signalling

Eva S. Werstiuk³  Michel P. Rathbone¹  Patrizia Ballerini²  Christian Bau³  Iolanda D’Alimonte²  Shucui Jiang³  Kathleen M. Pettifer³ 

[1] McMaster University$$McMaster University, Health Sciences Center$$;School of Medicine, University of Chieti$$;McMaster University$$

关键词: SH-SY5Y human neuroblastoma cells;   

DOI  :  10.1007/s11302-007-9073-z

学科分类：分子生物学，细胞生物学和基因

来源: Springer

【 摘 要 】

Guanosine exerts neuroprotective effects in the central nervous system. Apoptosis, a morphological form of programmed cell death, is implicated in the pathophysiology of Parkinson’s disease (PD). MPP⁺, a dopaminergic neurotoxin, produces in vivo and in vitro cellular changes characteristic of PD, such as cytotoxicity, resulting in apoptosis. Undifferentiated human SH-SY5Y neuroblastoma cells had been used as an in vitro model of Parkinson’s disease. We investigated if extracellular guanosine affected MPP⁺-induced cytotoxicity and examined the molecular mechanisms mediating its effects. Exposure of neuroblastoma cells to MPP⁺ (10 μM–5 mM for 24–72 h) induced DNA fragmentation in a time-dependent manner (p < 0.05). Administration of guanosine (100 μM) before, concomitantly with or, importantly, after the addition of MPP⁺ abolished MPP⁺-induced DNA fragmentation. Addition of MPP⁺ (500 μM) to cells increased caspase-3 activity over 72 h (p < 0.05), and this was abolished by pre- or co-treatment with guanosine. Exposure of cells to pertussis toxin prior to MPP⁺ eliminated the anti-apoptotic effect of guanosine, indicating that this effect is dependent on a Gi protein-coupled receptor, most likely the putative guanosine receptor. The protection by guanosine was also abolished by the selective inhibitor of the enzyme PI-3-K/Akt/PKB (LY294002), confirming that this pathway plays a decisive role in this effect of guanosine. Neither MPP⁺ nor guanosine had any significant effect on α-synuclein expression. Thus, guanosine antagonizes and reverses MPP⁺-induced cytotoxicity of neuroblastoma cells via activation of the cell survival pathway, PI-3-K/Akt/PKB. Our results suggest that guanosine may be an effective pharmacological intervention in PD.

【 授权许可】

Unknown