Dopamine melanin-loaded PC12 cells: a model for studies on pigmented neurons.
The most conspicuous feature in idiopathic parkinsonism is the degeneration of pigmented neurons in the substantia nigra. A major problem for the study of the significance of neuromelanin for the development of parkinsonism is that common experimental animals lack neuromelanin in substantia nigra. The aim of this study was to develop an in vitro model that could be used to study the role of neuromelanin in chemically induced toxicity in dopaminergic cells. Cultured neuron-like PC12 cells were exposed to synthetic dopamine melanin (0-1.0 mg/ml) for 48 h, resulting in uptake of dopamine melanin particles into the cells. The intracellular distribution of dopamine melanin granules was similar to that found in neuromelanin-containing neurons. Dopamine melanin, up to 0.5 mg/ml, had negligible effects on ultrastructure, induction of the endoplasmic reticulum-stress protein glucose regulating protein 78, activation of caspase-3 and cell viability. The decreased cell viability in response to the cytotoxic peptide amyloid-beta25-35 was similar in melanin-loaded cells and in control cells without melanin. The results of the studies suggest that melanin-loaded PC12 cells can serve as an in vitro model for studies on the role of neuromelanin for the toxicity of chemicals, in particular neurotoxicants with melanin affinity, in pigmented neurons.
Ostergren
Anna
A
Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden.
Svensson
Anne-Lie
AL
Lindquist
Nils Gunnar
NG
Brittebo
Eva B
EB
D016229:Amyloid beta-Peptides / Q000633:toxicity; D000818:Animals; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D004789:Enzyme Activation; D006360:Heat-Shock Proteins / Q000096:biosynthesis; D008543:Melanins / Q000378:metabolism* / Q000494:pharmacology; D046529:Microscopy, Electron, Transmission; D018832:Molecular Chaperones / Q000096:biosynthesis; D009474:Neurons / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D016716:PC12 Cells; D010446:Peptide Fragments / Q000633:toxicity; D010858:Pigmentation; D051381:Rats; D000091342:Endoplasmic Reticulum Chaperone BiP
D016229:Amyloid beta-Peptides; D053148:Caspase 3; D020169:Caspases; D006360:Heat-Shock Proteins; D008543:Melanins; D018832:Molecular Chaperones; D010446:Peptide Fragments; C051684:GRP78 protein, rat; D000091342:Endoplasmic Reticulum Chaperone BiP; C074636:amyloid beta-protein (25-35); C081789:dopamine melanin; C014121:neuromelanin; C505410:Casp3 protein, rat