title: One at a time, live tracking of NGF axonal transport using quantum dots.
abstract: Retrograde axonal transport of nerve growth factor (NGF) signals is critical for the survival, differentiation, and maintenance of peripheral sympathetic and sensory neurons and basal forebrain cholinergic neurons. However, the mechanisms by which the NGF signal is propagated from the axon terminal to the cell body are yet to be fully elucidated. To gain insight into the mechanisms, we used quantum dot-labeled NGF (QD-NGF) to track the movement of NGF in real time in compartmentalized culture of rat dorsal root ganglion (DRG) neurons. Our studies showed that active transport of NGF within the axons was characterized by rapid, unidirectional movements interrupted by frequent pauses. Almost all movements were retrograde, but short-distance anterograde movements were occasionally observed. Surprisingly, quantitative analysis at the single molecule level demonstrated that the majority of NGF-containing endosomes contained only a single NGF dimer. Electron microscopic analysis of axonal vesicles carrying QD-NGF confirmed this finding. The majority of QD-NGF was found to localize in vesicles 50-150 nm in diameter with a single lumen and no visible intralumenal membranous components. Our findings point to the possibility that a single NGF dimer is sufficient to sustain signaling during retrograde axonal transport to the cell body.
authors: Department of Physics, Stanford University, Stanford, CA 94305, USA.
authors: Bianxiao
authors: B
authors: Cui
authors: Chengbiao
authors: C
authors: Wu
authors: Liang
authors: L
authors: Chen
authors: Alfredo
authors: A
authors: Ramirez
authors: Elaine L
authors: EL
authors: Bearer
authors: Wei-Ping
authors: WP
authors: Li
authors: William C
authors: WC
authors: Mobley
authors: Steven
authors: S
authors: Chu
mesh_terms: D000818:Animals; D001370:Axonal Transport / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D011992:Endosomes / Q000187:drug effects; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D008854:Microscopy, Electron; D020932:Nerve Growth Factor / Q000378:metabolism* / Q000494:pharmacology*; D045663:Quantum Dots; D051381:Rats; D017207:Rats, Sprague-Dawley; D020917:Receptor, trkA / Q000378:metabolism; D013997:Time Factors; D020696:rab5 GTP-Binding Proteins / Q000378:metabolism
chemical_list: D020932:Nerve Growth Factor; D020917:Receptor, trkA; D048049:Extracellular Signal-Regulated MAP Kinases; D020696:rab5 GTP-Binding Proteins
references: Science. 2002 Feb 22;295(5559):1536-9
references: 11799202
references: J Cell Biol. 2002 Jan 21;156(2):233-9
references: 11807088
references: J Cell Biol. 2002 May 13;157(4):679-91
references: 12011113
references: Curr Opin Neurobiol. 2002 Jun;12(3):268-74
references: 12049932
references: Hum Mol Genet. 2003 Apr 15;12(8):813-22
references: 12668605
references: J Neurosci. 2003 Apr 15;23(8):3209-20
references: 12716928
references: Neuron. 2003 Jul 3;39(1):57-68
references: 12848932
references: Neuron. 2003 Jul 3;39(1):69-84
references: 12848933
references: J Neurobiol. 2004 Feb 5;58(2):207-16
references: 14704953
references: Nat Biotechnol. 2004 Feb;22(2):198-203
references: 14704683
references: J Am Chem Soc. 2004 Feb 11;126(5):1324-5
references: 14759174
references: Cell. 2004 Jul 23;118(2):243-55
references: 15260993
references: Proc Natl Acad Sci U S A. 1977 Oct;74(10):4516-9
references: 270699
references: J Neurosci. 1982 Apr;2(4):431-42
references: 7069465
references: Neurosci Lett. 1983 Aug 19;39(1):1-4
references: 6195560
references: J Neurochem. 1986 Feb;46(2):641-8
references: 3001230
references: Brain Res. 1986 Jul;387(1):53-62
references: 3742234
references: J Neurosci. 1997 Feb 15;17(4):1282-90
references: 9006972
references: J Cell Biol. 1997 Jul 28;138(2):411-21
references: 9230082
references: Cold Spring Harb Symp Quant Biol. 1996;61:389-406
references: 9246468
references: Proc Natl Acad Sci U S A. 1997 Sep 2;94(18):9909-14
references: 9275225
references: J Neurosci. 1997 Sep 15;17(18):7007-16
references: 9278536
references: Brain Res. 1998 Jul 6;798(1-2):67-74
references: 9666080
references: Brain Res Brain Res Protoc. 1999 Jan;3(3):308-12
references: 9974146
references: J Neurosci. 1999 Sep 15;19(18):7889-900
references: 10479691
references: J Neurosci. 2005 Mar 2;25(9):2181-91
references: 15745944
references: Nano Lett. 2005 Apr;5(4):603-7
references: 15826094
references: J Neurosci. 2005 May 25;25(21):5236-47
references: 15917464
references: Nat Rev Neurosci. 2005 Aug;6(8):615-25
references: 16062170
references: Nat Methods. 2005 Aug;2(8):599-605
references: 16094385
references: Nat Methods. 2005 Oct;2(10):743-9
references: 16179920
references: IEEE Trans Image Process. 2005 Sep;14(9):1384-95
references: 16190473
references: Curr Opin Neurobiol. 2005 Oct;15(5):568-75
references: 16150591
references: Biomaterials. 2006 Mar;27(9):1679-87
references: 16318871
references: Hum Mol Genet. 2006 May 1;15(9):1451-63
references: 16565160
references: Neuron. 2006 Jul 6;51(1):29-42
references: 16815330
references: Science. 2000 Jun 16;288(5473):2048-51
references: 10856219
references: Mol Biol Cell. 2000 Jul;11(7):2283-95
references: 10888668
references: Methods Mol Biol. 2001;169:195-216
references: 11142011
references: Cytometry. 2001 Mar 1;43(3):182-8
references: 11170104
references: J Neurosci. 2001 Aug 1;21(15):5406-16
references: 11466412
references: Annu Rev Neurosci. 2001;24:1217-81
references: 11520933
references: Science. 2002 Feb 22;295(5559):1471-3
references: 11859179