APP Binds to the EGFR Ligands HB-EGF and EGF, Acting Synergistically with EGF to Promote ERK Signaling and Neuritogenesi
- PDF / 5,794,190 Bytes
- 21 Pages / 595.276 x 790.866 pts Page_size
- 68 Downloads / 141 Views
APP Binds to the EGFR Ligands HB-EGF and EGF, Acting Synergistically with EGF to Promote ERK Signaling and Neuritogenesis Joana F. da Rocha 1 & Luísa Bastos 1,2 & Sara C. Domingues 1 & Ana R. Bento 1 & Uwe Konietzko 3 & Odete A. B. da Cruz e Silva 1 & Sandra I. Vieira 1 Received: 11 June 2020 / Accepted: 17 September 2020 # Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract The amyloid precursor protein (APP) is a transmembrane glycoprotein central to Alzheimer’s disease (AD) with functions in brain development and plasticity, including in neurogenesis and neurite outgrowth. Epidermal growth factor (EGF) and heparinbinding EGF-like growth factor (HB-EGF) are well-described neurotrophic and neuromodulator EGFR ligands, both implicated in neurological disorders, including AD. Pro-HB-EGF arose as a putative novel APP interactor in a human brain cDNA library yeast two-hybrid screen. Based on their structural and functional similarities, we first aimed to verify if APP could bind to (HB-)EGF proforms. Here, we show that APP interacts with these two EGFR ligands, and further characterized the effects of APP-EGF interaction in ERK activation and neuritogenesis. Yeast co-transformation and co-immunoprecipitation assays confirmed APP interaction with HB-EGF. Co-immunoprecipitation also revealed that APP binds to cellular pro-EGF. Overexpression of HB-EGF in HeLa cells, or exposure of SH-SY5Y cells to EGF, both resulted in increased APP protein levels. EGF and APP were observed to synergistically activate the ERK pathway, crucial for neuronal differentiation. Immunofluorescence analysis of cellular neuritogenesis in APP overexpression and EGF exposure conditions confirmed a synergistic effect in promoting the number and the mean length of neurite-like processes. Synergistic ERK activation and neuritogenic effects were completely blocked by the EGFR inhibitor PD 168393, implying APP/EGF-induced activation of EGFR as part of the mechanism. This work shows novel APP protein interactors and provides a major insight into the APP/EGFdriven mechanisms underlying neurite outgrowth and neuronal differentiation, with potential relevance for AD and for adult neuroregeneration. Keywords APP interactors and signaling . HB-EGF and EGF ligands . EGFR activation . ERK signaling . Neuronal differentiation and regeneration
Introduction Odete A. B. da Cruz e Silva and Sandra I. Vieira contributed equally to this work. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s12035-020-02139-2) contains supplementary material, which is available to authorized users. * Sandra I. Vieira [email protected] 1
Institute of Biomedicine (iBiMED), Department of Medical Sciences, University of Aveiro, Agra do Crasto, 3810-193 Aveiro, Portugal
2
Present address: Roche Sistemas de Diagnósticos, Lda, 2720-413 Amadora, Portugal
3
Institute for Regenerative Medicine (IREM), University of Zurich, Zurich, Switzerland
The amyloid precursor protein (APP) is a type 1 integral membrane glycoprotein
Data Loading...
