Involvement of dopaminergic neuronal cystatin C in neuronal injury-induced microglial activation and neurotoxicity.
Factors released from injured dopaminergic (DA) neurons may trigger microglial activation and set in motion a vicious cycle of neuronal injury and inflammation that fuels progressive DA neurodegeneration in Parkinson's disease. In this study, using proteomic and immunoblotting analysis, we detected elevated levels of cystatin C in conditioned media (CM) from 1-methyl-4-phenylpyridinium and dieldrin-injured rat DA neuronal cells. Immunodepletion of cystatin C significantly reduced the ability of DA neuronal CM to induce activation of rat microglial cells as determined by up-regulation of inducible nitric oxide synthase, production of free radicals and release of proinflammatory cytokines as well as activated microglia-mediated DA neurotoxicity. Treatment of the cystatin C-containing CM with enzymes that remove O- and sialic acid-, but not N-linked carbohydrate moieties markedly reduced the ability of the DA neuronal CM to activate microglia. Taken together, these results suggest that DA neuronal cystatin C plays a role in the neuronal injury-induced microglial activation and neurotoxicity. These findings from the rat DA neuron-microglia in vitro model may help guide continued investigation to define the precise role of cystatin C in the complex interplay among neurons and glia in the pathogenesis of Parkinson's disease.
Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL 32610, USA.
Garima
G
Dutta
David S
DS
Barber
Ping
P
Zhang
Nicholas J
NJ
Doperalski
Bin
B
Liu
D000818:Animals; D015153:Blotting, Western; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004396:Coloring Agents; D017077:Culture Media, Conditioned; D055316:Cystatin C / Q000378:metabolism / Q000502:physiology*; D016207:Cytokines / Q000378:metabolism; D004026:Dieldrin / Q000633:toxicity; D059290:Dopaminergic Neurons / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D005455:Fluorescent Antibody Technique; D006031:Glycosylation; D007249:Inflammation / Q000473:pathology; D020267:MPTP Poisoning / Q000473:pathology; D008262:Macrophage Activation / Q000187:drug effects / Q000502:physiology*; D017628:Microglia / Q000187:drug effects / Q000502:physiology*; D009153:Mutagens / Q000633:toxicity; D009474:Neurons / Q000473:pathology*; D020258:Neurotoxicity Syndromes / Q000473:pathology*; D009573:Nitrites / Q000378:metabolism; D040901:Proteomics; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D013778:Tetrazolium Salts; D013844:Thiazoles
D004396:Coloring Agents; D017077:Culture Media, Conditioned; D055316:Cystatin C; D016207:Cytokines; D009153:Mutagens; D009573:Nitrites; D017382:Reactive Oxygen Species; D013778:Tetrazolium Salts; D013844:Thiazoles; C022616:thiazolyl blue; D004026:Dieldrin