RNA interference silencing of the adaptor molecules ShcC and Fe65 differentially affect amyloid precursor protein processing and Abeta generation.
The amyloid precursor protein (APP) and its pathogenic by-product amyloid-beta protein (Abeta) play central roles in Alzheimer disease (AD) neuropathogenesis. APP can be cleaved by beta-secretase (BACE) and alpha-secretase to produce APP-C99 and APP-C83. These C-terminal fragments can then be cleaved by gamma-secretase to produce Abeta and p3, respectively. p3 has been reported to promote apoptosis, and Abeta is the key component of senile plaques in AD brain. APP adaptor proteins with phosphotyrosine-binding domains, including ShcA (SHC1), ShcC (SHC3), and Fe65 (APBB1), can bind to and interact with the conserved YENPTY motif in the APP-C terminus. Here we have described for the first time the effects of RNA interference (RNAi) silencing of ShcA, ShcC, and Fe65 expression on APP processing and Abeta production. RNAi silencing of ShcC led to reductions in the levels of APP-C-terminal fragments (APP-CTFs) and Abeta in H4 human neuroglioma cells stably overexpressing full-length APP (H4-FL-APP cells) but not in those expressing APP-C99 (H4-APP-C99 cells). RNAi silencing of ShcC also led to reductions in BACE levels in H4-FL-APP cells. In contrast, RNAi silencing of the homologue ShcA had no effect on APP processing or Abeta levels. RNAi silencing of Fe65 increased APP-CTF levels, although also decreasing Abeta levels in H4-FL-APP cells. These findings suggest that pharmacologically blocking interaction of APP with ShcC and Fe65 may provide novel therapeutic strategies against AD.
Xie
Zhongcong
Z
Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Charlestown, Massachusetts 02129-2060; Department of Anesthesia and Critical Care, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129-2060, and.
Dong
Yuanlin
Y
Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Charlestown, Massachusetts 02129-2060; Department of Anesthesia and Critical Care, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129-2060, and.
Maeda
Uta
U
Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Charlestown, Massachusetts 02129-2060; Department of Anesthesia and Critical Care, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129-2060, and.
Xia
Weiming
W
Center for Neurologic Diseases, Harvard Institute of Medicine and Harvard Medical School, Boston, Massachusetts 02115.
Tanzi
Rudolph E
RE
Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Charlestown, Massachusetts 02129-2060. Electronic address: tanzi@helix.mgh.harvard.edu.
D048868:Adaptor Proteins, Signal Transducing / Q000096:biosynthesis / Q000235:genetics; D000544:Alzheimer Disease / Q000235:genetics / Q000378:metabolism / Q000628:therapy; D053829:Amyloid Precursor Protein Secretases / Q000378:metabolism*; D016229:Amyloid beta-Peptides / Q000378:metabolism; D016564:Amyloid beta-Protein Precursor / Q000378:metabolism*; D045744:Cell Line, Tumor; D006801:Humans; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000235:genetics; D009479:Neuropeptides / Q000096:biosynthesis* / Q000235:genetics; D009687:Nuclear Proteins / Q000096:biosynthesis* / Q000235:genetics; D011485:Protein Binding; D011499:Protein Processing, Post-Translational / Q000235:genetics; D017434:Protein Structure, Tertiary; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D055765:Shc Signaling Adaptor Proteins; D013045:Species Specificity; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D000071427:Src Homology 2 Domain-Containing, Transforming Protein 3
C091042:APBB1 protein, human; D048868:Adaptor Proteins, Signal Transducing; D016229:Amyloid beta-Peptides; D016564:Amyloid beta-Protein Precursor; D009419:Nerve Tissue Proteins; D009479:Neuropeptides; D009687:Nuclear Proteins; D034741:RNA, Small Interfering; C528024:SHC1 protein, human; C122029:SHC3 protein, human; D055765:Shc Signaling Adaptor Proteins; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D000071427:Src Homology 2 Domain-Containing, Transforming Protein 3; C100690:amyloid beta-protein p3, human; D053829:Amyloid Precursor Protein Secretases