Journal of Neuroscience, Vol 10, 3469-3478, Copyright © 1990 by Society for Neuroscience
Human platelets contain brain-derived neurotrophic factor
H Yamamoto and ME Gurney
Department of Cell, Molecular, and Structural Biology, Northwestern University Medical School, Chicago, Illinois 60611.
Neurotrophic support to peripheral sensory neurons is provided by 2 factors
of related sequence, NGF and brain-derived neurotrophic factor (BDNF). NGF
is present in peripheral target tissues, while BDNF has only been reported
in the CNS. We now report the biological characterization and molecular
cloning of a cDNA for BDNF from human platelets. BDNF in human platelets
has biological activities very similar to those of BDNF obtained from adult
porcine brain in neuron- enriched cultures prepared from peripheral ganglia
of chick embryos at 8-12 d of incubation. BDNF from human platelets
promoted the survival and neurite outgrowth of placodal and neural
crest-derived sensory neurons, but not to parasympathetic or sympathetic
neurons. Activity of the factor was additive to that of NGF in dorsal root
ganglia (DRG) neuron cultures and is equivalent to porcine brain BDNF in
nodose ganglion neuron cultures. On SDS-PAGE, BDNF from human platelets is
recovered at an apparent molecular weight equivalent to porcine brain BDNF
(13,000 D). A BDNF cDNA fragment was amplified from human platelet RNA by
using a coupled reverse transcriptase-polymerase chain reaction. Molecular
cloning and DNA sequence analysis of the amplified cDNA fragment revealed
complete identity for the deduced amino acid sequences of human and porcine
BDNF [amino acid (aa) 10-108 of the mature factor]. Thus, human platelets
might provide an important source of BDNF for regenerating peripheral
sensory neurons at the site of nerve injury.
