Premium
Platelet‐derived growth factor‐b expression induced after rat peripheral nerve injuries
Author(s) -
Oya Takeshi,
Zhao YingLuan,
Takagawa Kiyoshi,
Kawaguchi Makoto,
Shirakawa Kamon,
Yamauchi Tadakazu,
Sasahara Masakiyo
Publication year - 2002
Publication title -
glia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.954
H-Index - 164
eISSN - 1098-1136
pISSN - 0894-1491
DOI - 10.1002/glia.10074
Subject(s) - schwann cell , regeneration (biology) , axon , platelet derived growth factor receptor , biology , sciatic nerve , platelet derived growth factor , peripheral nerve injury , nerve growth factor , microbiology and biotechnology , nerve guidance conduit , immunohistochemistry , neuroscience , growth factor , anatomy , immunology , receptor , biochemistry
Schwann cells are crucially important for peripheral nerve regeneration. These cells synthesize several factors that are supposed to enhance axonal regeneration when injured. Platelet‐derived growth factor (PDGF) B‐chain and its β‐receptor are expressed in Schwann cells in both normal peripheral nerves and culture. To elucidate the role of PDGF‐B in peripheral nerve regeneration, we investigated its expression in cut or crush‐injured rat sciatic nerves for up to 28 days. Northern blotting identified substantial increase of PDGF B‐chain transcripts in injured nerves. Immunohistochemistry demonstrated that protein products of the transcripts were augmented at the distal tip of swollen axons in proximal nerve segments and in regenerating axons. Soon after both types of injury, considerable amounts of PDGF‐B accumulated in numerous Schwann cells in distal segments of both models. With restoration of the axon–Schwann cell relationship in the crush model, levels of PDGF‐B tended to decrease, eventually returning to normal. In the cut model in which the relationship cannot be restored, the PDGF‐B was depleted to a very low level. The spatiotemporal correlation between PDGF‐B and cell proliferation was very close throughout the study. These results differed strikingly from those of our previous study of rat optic nerve transection, in which PDGF‐B was expressed only in a few recruited macrophages and glial cells. Augmented PDGF‐B expression after sciatic nerve injury might contribute to peripheral nerve regeneration because PDGF‐B is a mitogen and survival factor for Schwann cells and because it has trophic activity on neurons. GLIA 38:303–312, 2002. © 2002 Wiley‐Liss, Inc.