Deficiency of parkin causes neurodegeneration and accumulation of pathological α-synuclein in monkey models
Rui Han, … , Xiao-Jiang Li, Weili Yang
Rui Han, … , Xiao-Jiang Li, Weili Yang
Published October 15, 2024
Citation Information: J Clin Invest. 2024;134(20):e179633. https://doi.org/10.1172/JCI179633.
View: Text | PDF
Research Article Aging Neuroscience

Deficiency of parkin causes neurodegeneration and accumulation of pathological α-synuclein in monkey models

Abstract

Parkinson’s disease (PD) is characterized by age-dependent neurodegeneration and the accumulation of toxic phosphorylated α-synuclein (pS129-α-syn). The mechanisms underlying these crucial pathological changes remain unclear. Mutations in parkin RBR E3 ubiquitin protein ligase (PARK2), the gene encoding parkin that is phosphorylated by PTEN-induced putative kinase 1 (PINK1) to participate in mitophagy, cause early onset PD. However, current parkin-KO mouse and pig models do not exhibit neurodegeneration. In the current study, we utilized CRISPR/Cas9 technology to establish parkin-deficient monkey models at different ages. We found that parkin deficiency leads to substantia nigra neurodegeneration in adult monkey brains and that parkin phosphorylation decreases with aging, primarily due to increased insolubility of parkin. Phosphorylated parkin is important for neuroprotection and the reduction of pS129-α-syn. Consistently, overexpression of WT parkin, but not a mutant form that cannot be phosphorylated by PINK1, reduced the accumulation of pS129-α-syn. These findings identify parkin phosphorylation as a key factor in PD pathogenesis and suggest it as a promising target for therapeutic interventions.

Authors

Rui Han, Qi Wang, Xin Xiong, Xiusheng Chen, Zhuchi Tu, Bang Li, Fei Zhang, Chunyu Chen, Mingtian Pan, Ting Xu, Laiqiang Chen, Zhifu Wang, Yanting Liu, Dajian He, Xiangyu Guo, Feng He, Peng Wu, Peng Yin, Yunbo Liu, Xiaoxin Yan, Shihua Li, Xiao-Jiang Li, Weili Yang

×

Figure 1

Parkin mutations do not induce neuronal loss in the developing monkey brain.

Options: View larger image (or click on image) Download as PowerPoint
Parkin mutations do not induce neuronal loss in the developing monkey br...
(A) Schematic diagram illustrating the establishment of an embryonic PARK2 targeting monkey model. One-cell stage embryos of Macaque monkeys were injected with parkin gRNA and Cas9 mRNA. Embryos at the 4–8 cell stage were transferred to surrogates to produce newborn monkeys with parkin mutations. (B) Parkin protein domains and targeted regions. Two parkin gRNAs (exon 2 and exon 3) were designed to target the monkey parkin (PARK2) gene. Two fetal monkeys (Park-1 and Park-2), one 1.5-year-old monkey (Park-3), and one 3-year-old monkey (Park-4) were found to carry parkin mutations generated by CRISPR/Cas9 targeting. (C and D) Western blotting showing a reduction in parkin levels in the brain tissues of Park-1 and Park-2 monkeys in C, as well as 3-year-old Park-4 monkey in D, without alterations in neuronal proteins (NeuN, PSD95) when compared with age-matched WT monkeys. Representative Western blotting results of multiple technical replicates from 3 WT and 3 parkin mutant monkeys. Ctx, cortex; Str, striatum; Cere, cerebellum; BS, brain stem. (E) In utero delivery of lentiviral parkin gRNA/Cas9 into the lateral ventricle of the fetal monkey brain at approximately G55. (F) Widespread expression of GFP, reflecting lentiviral parkin gRNA/Cas9 transduction in the brain of the newborn monkey. Scale bar: 1 mm. (G) Representative Western blotting results of 3 independent experiments showing reduced expression of parkin in the lentiviral-infected brain regions. Loss of parkin did not affect NeuN expression. (H) Representative images of NeuN labeling of the cortical region in the parkin-targeted newborn monkey, showing that targeting parkin did not affect NeuN expression or neuronal morphology when compared with untargeted cells. Multiple technical replicates were performed.