title: Protective effect of orexin-A on 6-hydroxydopamine-induced neurotoxicity in SH-SY5Y human dopaminergic neuroblastoma cells.
abstract: Parkinson's disease (PD) is a progressive neurodegenerative disease characterized by progressive and selective death of midbrain dopaminergic neurons. Pharmacologic treatment of PD can be divided into symptomatic and neuroprotective therapies. Orexin-A (hypocretin-1) is a hypothalamic peptide that exerts its biological effects by stimulation of two specific, membrane-bound orexin receptors. Recent studies have shown that orexin-A has a protective role during neuronal damage. Here, we investigated the effects of orexin-A on 6-OHDA-induced neurotoxicity in human neuroblastoma SH-SY5Y cell line as an in vitro model of Parkinson's disease. Cell damage was induced by 150μM 6-OHDA and the cells viability was examined by MTT assay. Intracellular reactive oxygen species (ROS) was determined by fluorescence spectrophotometry method. Immunoblotting and DNA analysis were also employed to determine the levels of biochemical markers of apoptosis in the cells. The data showed that 6-OHDA could decrease the viability of the cells. In addition, intracellular ROS, activated caspase 3, Bax/Bcl-2 ratio, cytochrome c as well as DNA fragmentation were significantly increased in 6-OHDA-treated cells. Pretreatment of cells with orexin-A (80pM) elicited protective effect and reduced biochemical markers of cell death. The results suggest that orexin-A has protective effects against 6-OHDA-induced neurotoxicity and its protective effects are accompanied by its antioxidant and anti-apoptotic properties and contribute to our knowledge of the pharmacology of orexin-A.
authors.affiliation: Laboratory of Molecular Neuroscience, Kerman Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran; Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran. Electronic address: semahani@yahoo.com.
authors.forename: Saeed
authors.initials: S
authors.lastname: Esmaeili-Mahani
authors.forename: Somayeh
authors.initials: S
authors.lastname: Vazifekhah
authors.forename: Hamzeh
authors.initials: H
authors.lastname: Pasban-Aliabadi
authors.forename: Mehdi
authors.initials: M
authors.lastname: Abbasnejad
authors.forename: Vahid
authors.initials: V
authors.lastname: Sheibani
mesh_terms: D045744:Cell Line, Tumor; D004298:Dopamine / Q000378:metabolism*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000502:physiology*; D009447:Neuroblastoma / Q000378:metabolism* / Q000473:pathology; D009479:Neuropeptides / Q000502:physiology*; D000068797:Orexins; D016627:Oxidopamine / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013050:Spectrometry, Fluorescence
chemical_list: C000596229:HCRT protein, human; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins; D017382:Reactive Oxygen Species; D016627:Oxidopamine; D004298:Dopamine
keywords: 6-Hydroxydopamine; Apoptosis; Orexin-A; Parkinson’s disease; SH-SY5Y cells