Cytoplasmic mislocalization of RNA splicing factors and aberrant neuronal gene splicing in TDP-43 transgenic pig brain.
BACKGROUND
TAR DNA-binding protein 43 (TDP-43) is a nuclear protein, but it is redistributed in the neuronal cytoplasm in both amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Because small transgenic animal models often lack cytoplasmic TDP-43, how the cytoplasmic accumulation of TDP-43 contributes to these diseases remains unclear. The current study is aimed at studying the mechanism of cytoplasmic pathology of TDP-43.


RESULTS
We established transgenic pigs expressing mutant TDP-43 (M337V). This pig model shows severe phenotypes and early death. We found that transgenic TDP-43 is also distributed in the cytoplasm of neuronal cells in the spinal cord and brain. Transgenic TDP-43 interacts with PSF, an RNA splicing factor that associates with NeuN to regulate neuronal RNA splicing. The interaction of TDP-43, PSF and NeuN causes PSF and NeuN mislocalize into the neuronal cytoplasm in transgenic pigs. Consistently, abnormal PSF-related neuronal RNA splicing is seen in TDP-43 transgenic pigs. The cytoplasmic localization of PSF and NeuN as well as abnormal PSF-related neuronal RNA splicing was also found in ALS patient brains.


CONCLUSIONS
Our findings from a large mammalian model suggest that cytoplasmic mutant TDP-43 could reduce the nuclear function of RNA splicing factors, contributing to neuropathology.
State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China. ghwang85@gmail.com.|Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, 30322, USA. ghwang85@gmail.com.|University of Chinese Academy of Sciences, Beijing, 100049, China. ghwang85@gmail.com.
Guohao
G
Wang
Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China. yang_huaqiang@gibh.ac.cn.
Huaqiang
H
Yang
State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China. 231yansen@gmail.com.|Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, 30322, USA. 231yansen@gmail.com.
Sen
S
Yan
Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, 30322, USA. cwang5@emory.edu.
Chuan-En
CE
Wang
State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China. xdliu@genetics.ac.cn.|University of Chinese Academy of Sciences, Beijing, 100049, China. xdliu@genetics.ac.cn.
Xudong
X
Liu
Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China. zhao_bentian@gibh.ac.cn.
Bentian
B
Zhao
Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China. ouyang_zhen@gibh.ac.cn.
Zhen
Z
Ouyang
State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China. yinpeng177@163.com.
Peng
P
Yin
Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China. liu_zhaoming@gibh.ac.cn.
Zhaoming
Z
Liu
Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China. zhao_yu531@gibh.ac.cn.
Yu
Y
Zhao
Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China. liu_tao@gibh.ac.cn.
Tao
T
Liu
Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China. fan_nana@gibh.ac.cn.
Nana
N
Fan
Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China. guo_lin@gibh.ac.cn.
Lin
L
Guo
Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, 30322, USA. sli@emory.edu.
Shihua
S
Li
State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China. xli2@emory.edu.|Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, 30322, USA. xli2@emory.edu.
Xiao-Jiang
XJ
Li
Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China. lai_liangxue@gibh.ac.cn.
Liangxue
L
Lai
D000690:Amyotrophic Lateral Sclerosis / Q000473:pathology; D000818:Animals; D030801:Animals, Genetically Modified; D002490:Central Nervous System / Q000378:metabolism / Q000473:pathology; D003593:Cytoplasm / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000502:physiology; D004195:Disease Models, Animal; D006801:Humans; D009046:Motor Neurons / Q000473:pathology; D009133:Muscular Atrophy / Q000209:etiology; D009419:Nerve Tissue Proteins / Q000378:metabolism; D053652:Nuclear Transfer Techniques; D000072670:PTB-Associated Splicing Factor; D010641:Phenotype; D025941:Protein Interaction Mapping; D021381:Protein Transport; D012326:RNA Splicing; D016601:RNA-Binding Proteins / Q000378:metabolism; D013045:Species Specificity; D034421:Sus scrofa; D057177:TDP-43 Proteinopathies / Q000235:genetics* / Q000473:pathology
D004268:DNA-Binding Proteins; D009419:Nerve Tissue Proteins; D000072670:PTB-Associated Splicing Factor; D016601:RNA-Binding Proteins; C000598624:TARDBP protein, human