Microglial PHOX and Mac-1 are essential to the enhanced dopaminergic neurodegeneration elicited by A30P and A53T mutant alpha-synuclein.
Zhang, Wei 1,2; Dallas, Shannon 3; Zhang, Dan 1; Guo, Jian-Ping 4; Pang, Hao 1; Wilson, Belinda 1; Miller, David S. 3; Chen, Biao 5; Zhang, Wanqin 6; McGeer, Patrick L. 4; Hong, Jau-Shyong 1; Zhang, Jing 7,*
[Article]
Glia.
55(11):1178-1188, August 15, 2007.
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: [alpha]-Synuclein, a gene whose mutations, duplication, and triplication has been linked to autosomal dominant familial Parkinson's disease (fPD), appears to play a central role in the pathogenesis of sporadic PD (sPD) as well. Enhancement of neurodegeneration induced by mutant [alpha]-synuclein has been attributed to date largely to faster formation of [alpha]-synuclein aggregates in neurons. Recently, we reported that microglial activation enhances wild type (WT) [alpha]-synuclein-elicited dopaminergic neurodegeneration. In the present study, using a primary mesencephalic culture system, we tested whether mutated [alpha]-synuclein could activate microglia more powerfully than WT [alpha]-synuclein, thereby contributing to the accelerated neurodegeneration observed in fPD. The results showed that [alpha]-synuclein with the A30P or A53T mutations caused greater microglial activation than WT [alpha]-synuclein. Furthermore, the extent of microglial activation paralleled the degree of dopaminergic neurotoxicity induced by WT and mutant [alpha]-synuclein. Mutant [alpha]-synuclein also induced greater production of reactive oxygen species than WT [alpha]-synuclein by NADPH oxidase (PHOX), and PHOX activation was linked to direct activation of macrophage antigen-1 (Mac-1) receptor, rather than [alpha]-synuclein internalization via scavenger receptors. These results have, for the first time, demonstrated that microglia are also critical in enhanced neurotoxicity induced by mutant [alpha]-synuclein. (C) 2007 Wiley-Liss, Inc.
Copyright (C) 2007 John Wiley & Sons, Inc.