title: CSF-1 receptor signalling is governed by pre-requisite EHD1 mediated receptor display on the macrophage cell surface.
abstract: Colony stimulating factor-1 receptor (CSF-1R), a receptor tyrosine kinase (RTK), is the master regulator of macrophage biology. CSF-1 can bind CSF-1R resulting in receptor activation and signalling essential for macrophage functions such as proliferation, differentiation, survival, polarization, phagocytosis, cytokine secretion, and motility. CSF-1R activation can only occur after the receptor is presented on the macrophage cell surface. This process is reliant upon the underlying macrophage receptor trafficking machinery. However, the mechanistic details governing this process are incompletely understood. C-terminal Eps15 Homology Domain-containing (EHD) proteins have recently emerged as key regulators of receptor trafficking but have not yet been studied in the context of macrophage CSF-1R signalling. In this manuscript, we utilize primary bone-marrow derived macrophages (BMDMs) to reveal a novel function of EHD1 as a regulator of CSF-1R abundance on the cell surface. We report that EHD1-knockout (EHD1-KO) macrophages cell surface and total CSF-1R levels are significantly decreased. The decline in CSF-1R levels corresponds with reduced downstream macrophage functions such as cell proliferation, migration, and spreading. In EHD1-KO macrophages, transport of newly synthesized CSF-1R to the macrophage cell surface was reduced and was associated with the shunting of the receptor to the lysosome, which resulted in receptor degradation. These findings reveal a novel and functionally important role for EHD1 in governing CSF-1R signalling via regulation of anterograde transport of CSF-1R to the macrophage cell surface.
authors.affiliation: Eppley Cancer Institute for Research in Cancer & Allied Diseases, University of Nebraska Medical Center, Omaha, NE, United States.
authors.forename: Luke R
authors.initials: LR
authors.lastname: Cypher
authors.affiliation: Eppley Cancer Institute for Research in Cancer & Allied Diseases, University of Nebraska Medical Center, Omaha, NE, United States.
authors.forename: Timothy Alan
authors.initials: TA
authors.lastname: Bielecki
authors.affiliation: Department of Chemistry and Biochemistry, BioSNTR, South Dakota State University, Brookings, SD, United States.
authors.forename: Lu
authors.initials: L
authors.lastname: Huang
authors.affiliation: Department of Genetics, Cell Biology, & Anatomy, University of Nebraska Medical Center, Omaha, NE, United States.
authors.forename: Wei
authors.initials: W
authors.lastname: An
authors.affiliation: Department of Genetics, Cell Biology, & Anatomy, University of Nebraska Medical Center, Omaha, NE, United States.
authors.forename: Fany
authors.initials: F
authors.lastname: Iseka
authors.affiliation: Department of Biochemistry & Molecular Biology, University of Nebraska Medical Center, Omaha, NE, United States.
authors.forename: Eric
authors.initials: E
authors.lastname: Tom
authors.affiliation: Eppley Cancer Institute for Research in Cancer & Allied Diseases, University of Nebraska Medical Center, Omaha, NE, United States.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Storck
authors.affiliation: Department of Chemistry and Biochemistry, BioSNTR, South Dakota State University, Brookings, SD, United States.
authors.forename: Adam D
authors.initials: AD
authors.lastname: Hoppe
authors.affiliation: Eppley Cancer Institute for Research in Cancer & Allied Diseases, University of Nebraska Medical Center, Omaha, NE, United States; Department of Genetics, Cell Biology, & Anatomy, University of Nebraska Medical Center, Omaha, NE, United States.
authors.forename: Vimla
authors.initials: V
authors.lastname: Band
authors.affiliation: Eppley Cancer Institute for Research in Cancer & Allied Diseases, University of Nebraska Medical Center, Omaha, NE, United States; Department of Genetics, Cell Biology, & Anatomy, University of Nebraska Medical Center, Omaha, NE, United States. Electronic address: hband@unmc.edu.
authors.forename: Hamid
authors.initials: H
authors.lastname: Band
mesh_terms: D000818:Animals; D001324:Autoantigens / Q000378:metabolism; D002451:Cell Compartmentation / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism*; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D008247:Lysosomes / Q000187:drug effects / Q000378:metabolism; D018942:Macrolides / Q000494:pharmacology; D016173:Macrophage Colony-Stimulating Factor / Q000378:metabolism; D008264:Macrophages / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D014176:Protein Biosynthesis / Q000187:drug effects; D059748:Proteolysis / Q000187:drug effects; D016186:Receptor, Macrophage Colony-Stimulating Factor / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D033921:Vesicular Transport Proteins / Q000378:metabolism*
chemical_list: D001324:Autoantigens; C485640:Ehd1 protein, mouse; C097741:Golgin subfamily A member 2; D018942:Macrolides; D008565:Membrane Proteins; D033921:Vesicular Transport Proteins; D016173:Macrophage Colony-Stimulating Factor; C040929:bafilomycin A1; D016186:Receptor, Macrophage Colony-Stimulating Factor
keywords: CSF-1R; Cell signalling; Cell surface; Macrophage; Proliferation; Receptor tyrosine kinase