title: Nanoparticle-mediated signaling endosome localization regulates growth cone motility and neurite growth.
abstract: Understanding neurite growth regulation remains a seminal problem in neurobiology. During development and regeneration, neurite growth is modulated by neurotrophin-activated signaling endosomes that transmit regulatory signals between soma and growth cones. After injury, delivering neurotrophic therapeutics to injured neurons is limited by our understanding of how signaling endosome localization in the growth cone affects neurite growth. Nanobiotechnology is providing new tools to answer previously inaccessible questions. Here, we show superparamagnetic nanoparticles (MNPs) functionalized with TrkB agonist antibodies are endocytosed into signaling endosomes by primary neurons that activate TrkB-dependent signaling, gene expression and promote neurite growth. These MNP signaling endosomes are trafficked into nascent and existing neurites and transported between somas and growth cones in vitro and in vivo. Manipulating MNP-signaling endosomes by a focal magnetic field alters growth cone motility and halts neurite growth in both peripheral and central nervous system neurons, demonstrating signaling endosome localization in the growth cone regulates motility and neurite growth. These data suggest functionalized MNPs may be used as a platform to study subcellular organelle localization and to deliver nanotherapeutics to treat injury or disease in the central nervous system.
authors: Bascom Palmer Eye Institute, Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
authors: Michael B
authors: MB
authors: Steketee
authors: Stavros N
authors: SN
authors: Moysidis
authors: Xiao-Lu
authors: XL
authors: Jin
authors: Jessica E
authors: JE
authors: Weinstein
authors: Wolfgang
authors: W
authors: Pita-Thomas
authors: Hemalatha B
authors: HB
authors: Raju
authors: Siraj
authors: S
authors: Iqbal
authors: Jeffrey L
authors: JL
authors: Goldberg
mesh_terms: D000818:Animals; D015153:Blotting, Western; D017931:DNA Primers / Q000235:genetics; D011992:Endosomes / Q000378:metabolism*; D005260:Female; D020439:Growth Cones / Q000502:physiology*; D007091:Image Processing, Computer-Assisted; D008280:Magnetics; D053758:Nanoparticles; D036103:Nanotechnology / Q000379:methods*; D009414:Nerve Growth Factors; D016501:Neurites / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction; D020813:Receptor, trkB / Q000819:agonists; D015398:Signal Transduction / Q000502:physiology*; D059008:Time-Lapse Imaging
chemical_list: D017931:DNA Primers; D009414:Nerve Growth Factors; D020813:Receptor, trkB