| First Author | Lastres-Becker I | Year | 2012 |
| Journal | Hum Mol Genet | Volume | 21 |
| Issue | 14 | Pages | 3173-92 |
| PubMed ID | 22513881 | Mgi Jnum | J:185278 |
| Mgi Id | MGI:5428062 | Doi | 10.1093/hmg/dds143 |
| Citation | Lastres-Becker I, et al. (2012) alpha-Synuclein expression and Nrf2 deficiency cooperate to aggravate protein aggregation, neuronal death and inflammation in early-stage Parkinson's disease. Hum Mol Genet 21(14):3173-92 |
| abstractText | Although alpha-synuclein (alpha-SYN) aggregation is a hallmark of sporadic and familial Parkinson's disease (PD), it is not known how it contributes to early events of PD pathogenesis such as oxidative and inflammatory stress. Here, we addressed this question in a new animal model based on stereotaxic delivery of an adeno-associated viral vector (rAAV) for expression of human alpha-SYN in the ventral midbrain of mice lacking the transcription factor Nrf2 (Nrf2(-/-)). Two months after surgery, Nrf2(-/-) mice exhibited exacerbated degeneration of nigral dopaminergic neurons and increased dystrophic dendrites, reminiscent of Lewy neurites, which correlated with impaired proteasome gene expression and activity. Dopaminergic neuron loss was associated with an increase in neuroinflammation and gliosis that were intensified in Nrf2(-/-) mice. In response to exogenously added alpha-SYN, Nrf2(-/-) microglia failed to activate the expression of two anti-inflammatory genes, heme oxygenase-1 (HO-1) and nicotinamide adenine dinucleotide phosphate quinone oxidorreductase-1 (NQO1). This impaired Nrf2 response correlated with a shift in the microglial activation profile, towards increased production of proinflammatory markers, IL-6, IL-1beta and iNOS and reduced phagocytic capacity of fluorescent beads, and lower messenger RNA levels for TAM receptors Axl and Mer. Postmortem brain tissue samples from patients in early- to middle-stage progression of PD showed increased HO-1 expression in astrocytes and microglia, suggesting an attempt of the diseased brain to compensate these hallmarks of PD through activation of the Nrf2 pathway. This study demonstrates that alpha-SYN and Nrf2 deficiency cooperate on protein aggregation, neuroinflammation and neuronal death and provides a bifactorial animal model to study early-stage PD. |
