Characterization of lactoferrin receptor in brain endothelial capillary cells and mouse brain.
We present, herein, the evidence for lactoferrin (Lf) binding sites in brain endothelial capillary cells (BCECs) and mouse brain. The results from confocal microscopy showed the presence of Lf receptors on the surface of BCECs and the receptor-mediated endocytosis for Lf to enter the cells. Saturation binding analyses revealed that Lf receptors exhibited two classes of binding sites in BCECs (high affinity: dissociation constant (K (d)) = 6.77 nM, binding site density (B (max)) = 10.3 fmol bound/mug protein; low affinity: K (d) = 4815 nM, B (max) = 1190 fmol bound/mug protein) and membrane preparations of mouse brain (high affinity: K (d) = 10.61 nM, B (max) = 410 fmol bound/mug protein; low affinity: K (d) = 2228 nM, B (max) = 51641 fmol bound/mug protein). The distribution study indicated the effective uptake of (125)I-Lf in brain after intravenous administration. The present study provides experimental evidence for the application of Lf as a novel ligand for brain targeting.
Huang
Rong-qin
RQ
Department of Pharmaceutics, School of Pharmacy, Fudan University, Shanghai, China.
Ke
Wei-lun
WL
Qu
Ying-hua
YH
Zhu
Jian-hua
JH
Pei
Yuan-ying
YY
Jiang
Chen
C
D000818:Animals; D002196:Capillaries / Q000166:cytology / Q000378:metabolism; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000098:blood supply / Q000166:cytology / Q000378:metabolism*; D004705:Endocytosis / Q000502:physiology; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D007781:Lactoferrin / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D011956:Receptors, Cell Surface / Q000378:metabolism*
D011956:Receptors, Cell Surface; C038340:lactoferrin receptors; D007781:Lactoferrin