Defects in Mitochondrial Biogenesis Drive Mitochondrial Alterations in PARKIN-Deficient Human Dopamine Neurons
STEM CELL REPORTS
Authors: Kumar, Manoj; Acevedo-Cintron, Jesus; Jhaldiyal, Aanishaa; Wang, Hu; Andrabi, Shaida A.; Eacker, Stephen; Karuppagounder, Senthilkumar S.; Brahmachari, Saurav; Chen, Rong; Kim, Hyesoo; Ko, Han Seok; Dawson, Valina L.; Dawson, Ted M.
Abstract
Mutations and loss of activity in PARKIN, an E3 ubiquitin ligase, play a role in the pathogenesis of Parkinson's disease (PD). PARKIN regulates many aspects of mitochondrial quality control including mitochondrial autophagy (mitophagy) and mitochondrial biogenesis. Defects in mitophagy have been hypothesized to play a predominant role in the loss of dopamine (DA) neurons in PD. Here, we show that although there are defects in mitophagy in human DA neurons lacking PARKIN, the mitochondrial deficits are primarily due to defects in mitochondrial biogenesis that are driven by the upregulation of PARIS and the subsequent downregulation of PGC-1 alpha. CRISPR/Cas9 knockdown of PARIS completely restores the mitochondrial biogenesis defects and mitochondrial function without affecting the deficits in mitophagy. These results highlight the importance mitochondrial biogenesis versus mitophagy in the pathogenesis of PD due to inactivation or loss of PARKIN in human DA neurons.
Proteome landscape and spatial map of mouse primordial germ cells
SCIENCE CHINA-LIFE SCIENCES
Authors: Wang, Pan; Miao, Yilong; Li, Xiao-Han; Zhang, Na; Wang, Qilong; Yue, Wei; Sun, Shao-Chen; Xiong, Bo; Qiao, Jie; Li, Mo
Abstract
Primordial germ cells (PGCs) are precursors of both male and female gametes as fundamental materials for organism development. The transcriptome, methylome, and chromatin accessibility profiles of PGCs in both mice and humans have been recently reported. However, little is known about the characteristics of PGCs at the protein levels, which directly exert cellular functions. Here, we construct landscapes of both proteome and 3D spatial distribution of mouse PGCs at E11.5, E13.5 and E16.5 days, the three critical developmental windows for PGCs, sex differentiation, female meiosis initiation and male mitotic arrest. In each developmental stage of PGCs, nearly 2,000-3,000 proteins are identified, among which specific functional pathways such as oxidative phosphorylation, DNA damage repair, and meiotic cell cycle are involved for different events during PGCs development. Interestingly, by 3D modeling we find that PGCs spatially cluster into around 1,300 nests in genital ridge at E11.5 and the nest number is not increased by the exponential proliferation of PGCs. Comparative analysis of our proteomic data with published transcriptomic data does not show a close correlation, meaning that the practically executive factors are beyond the transcriptome. Thus, our work offers a valuable resource for the systematic investigations of PGC development at protein level and spatial map.