Brain-derived neurotrophic factor bound with lecithin derivative showed a markedly enhanced pharmacological potency due to its potent cell membrane affinity followed by prolonged MAPK activation.
We synthesized lecithinized brain-derived neurotrophic factor (lecithinized-BDNF), in which an average of three molecules of a lecithin derivative were bound to recombinant human BDNF. We evaluated its pharmacological activity in C57BL/KsJ-db/db mice, and assessed its targetability and affinity for the nervous system. Subcutaneously administered lecithinized-BDNF markedly reduced the plasma glucose level, food intake, and body weight in C57BL/KsJ-db/db diabetic mice. Its potency was more than 20 times greater than that of unmodified BDNF. We then studied the mechanism for the markedly enhanced pharmacological activity. In vitro cell growth activity of lecithinized-BDNF using the MTT assay was lower than unmodified BDNF, probably due to steric hindrance of the lecithin moieties. While the plasma BDNF level after subcutaneous administration of lecithinized-BDNF was not higher compared with unmodified BDNF. However, higher amount of lecithinized-BDNF accumulated in the spinal cord was observed. Lastly, we found that in vitro binding capacity of lecithinized-BDNF for PC-pAB1 neural cells was much higher than unmodified BDNF. Moreover, lecithinized-BDNF bound to PC-pAB1 cells did not exchange with an excessive amount of unmodified BDNF or an excess of lecithinized-BDNF. PC-pAB1 cells treated with lecithinized-BDNF showed sustained mitogen-activated protein kinase (MAPK, ERK1/2) activation. These data would indicate that the high affinity of lecithinized-BDNF for the target cells, followed by prolonged MAPK activation, would play an important role in its potent pharmacological activity.
Igarashi
Rie
R
The Frontier Medicine of the Institute of Medical Sciences, St Marianna University, School of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki, 216-8512, Japan. igarashi@marianna-u.ac.jp
Nakayama
Toshiaki
T
Takenaga
Mitsuko
M
Ichinohe
Manabu
M
Yamaguchi
Yoko
Y
Matsumoto
Kayo
K
Kitagawa
Aki
A
Nakamura
Natsumi
N
Kawai
Shinichi
S
Nakagawa
Tsutomu
T
Taiji
Mutsuo
M
Nakayama
Chikao
C
Mizushima
Yutaka
Y
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D015153:Blotting, Western; D001835:Body Weight / Q000187:drug effects; D001921:Brain / Q000378:metabolism; D019208:Brain-Derived Neurotrophic Factor / Q000008:administration & dosage* / Q000737:chemistry / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000097:blood; D004435:Eating / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D007457:Iodine Radioisotopes; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D010713:Phosphatidylcholines / Q000737:chemistry*; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology
D001786:Blood Glucose; D019208:Brain-Derived Neurotrophic Factor; D007457:Iodine Radioisotopes; D010713:Phosphatidylcholines; D011994:Recombinant Proteins; D020928:Mitogen-Activated Protein Kinases