Expression of transferrin binding protein in the capillaries of the brain in the developing chick embryo.
Transferrin-binding protein (TfBP) has been shown to be a novel protein, structurally related to the chicken heat shock protein 108. The physiological function of this protein, however, has not yet been established. Antiserum to TfBP selectively stains transferrin- and iron-rich oligodendrocytes and choroidal epithelium in the adult and embryonic chick brain, suggesting a role for this protein in transferrin and iron storage in these cells. In this study, we further demonstrate TfBP-immunoreactivity (IR) in the blood vessels of the embryonic chick central nervous system. A strong TfBP-IR was present in blood vessels from E6, declined from E10 and was absent by E18. Thus, the expression of the TfBP in the blood vessels precedes its expression in the oligodendrocytes. At the subcellular level, TfBP-IR was confined to the cytoplasm of capillary pericytes while the Tf-receptor IR was associated with the capillary endothelium of the brain. The up-regulated expression of TfBP, together with the Tf-receptor of the brain capillaries, suggests that pericytes may be associated with the high iron uptake required for the metabolic demands of the developing brain.
Kim
Dong Woon
DW
Department of Anatomy, Research Institute for Medical Sciences, Chungnam National University College of Medicine, Daejeon, 301-131, South Korea.
Lee
Ha Na
HN
Song
Ji Eun
JE
Jung
Kyung Jin
KJ
Yang
Woo-Mi
WM
Kwon
Kisang
K
Jeon
Gye Sun
GS
Lee
Young Ho
YH
Chung
Chun Kee
CK
Cho
Sa Sun
SS
D000818:Animals; D001921:Brain / Q000196:embryology / Q000378:metabolism*; D002196:Capillaries / Q000378:metabolism*; D002642:Chick Embryo; D007150:Immunohistochemistry; D008856:Microscopy, Fluorescence; D016253:Microscopy, Immunoelectron; D033863:Transferrin-Binding Proteins / Q000378:metabolism*
D033863:Transferrin-Binding Proteins