Reelin transiently promotes N-cadherin-dependent neuronal adhesion during mouse cortical development.
Reelin is an essential glycoprotein for the establishment of the highly organized six-layered structure of neurons of the mammalian neocortex. Although the role of Reelin in the control of neuronal migration has been extensively studied at the molecular level, the mechanisms underlying Reelin-dependent neuronal layer organization are not yet fully understood. In this study, we directly showed that Reelin promotes adhesion among dissociated neocortical neurons in culture. The Reelin-mediated neuronal aggregation occurs in an N-cadherin-dependent manner, both in vivo and in vitro. Unexpectedly, however, in a rotation culture of dissociated neocortical cells that gradually reaggregated over time, we found that it was the neural progenitor cells [radial glial cells (RGCs)], rather than the neurons, that tended to form clusters in the presence of Reelin. Mathematical modeling suggested that this clustering of RGCs could be recapitulated if the Reelin-dependent promotion of neuronal adhesion were to occur only transiently. Thus, we directly measured the adhesive force between neurons and N-cadherin by atomic force microscopy, and found that Reelin indeed enhanced the adhesiveness of neurons to N-cadherin; this enhanced adhesiveness began to be observed at 30 min after Reelin stimulation, but declined by 3 h. These results suggest that Reelin transiently (and not persistently) promotes N-cadherin-mediated neuronal aggregation. When N-cadherin and stabilized β-catenin were overexpressed in the migrating neurons, the transfected neurons were abnormally distributed in the superficial region of the neocortex, suggesting that appropriate regulation of N-cadherin-mediated adhesion is important for correct positioning of the neurons during neocortical development.
Department of Anatomy, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan.
Yuki
Y
Matsunaga
Department of Anatomy, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan.
Mariko
M
Noda
Faculty of Mathematics, Kyushu University, Nishi-ku, Fukuoka 819-0395, Japan.
Hideki
H
Murakawa
Department of Anatomy, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan.
Kanehiro
K
Hayashi
Department of Anatomy and Cell Biology, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya 466-8550, Japan.
Arata
A
Nagasaka
Department of Anatomy, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan.
Seika
S
Inoue
Department of Anatomy and Cell Biology, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya 466-8550, Japan.
Takaki
T
Miyata
Department of Anatomy and Cell Biology, Kyushu University Graduate School of Medical Sciences, Higashi-ku, Fukuoka 812-8582, Japan.
Takashi
T
Miura
Department of Anatomy, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan.
Ken-Ichiro
KI
Kubo
Department of Anatomy, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan; kazunori@keio.jp.
Kazunori
0000-0003-1864-9425
K
Nakajima
D000818:Animals; D015820:Cadherins / Q000235:genetics / Q000378:metabolism*; D002448:Cell Adhesion / Q000502:physiology*; D015816:Cell Adhesion Molecules, Neuronal / Q000235:genetics / Q000502:physiology*; D002465:Cell Movement; D002478:Cells, Cultured; D063928:Ependymoglial Cells; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000502:physiology*; D005260:Female; D055785:Gene Knockdown Techniques; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D008822:Mice, Transgenic; D018625:Microscopy, Atomic Force; D019579:Neocortex / Q000196:embryology*; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000502:physiology*; D055495:Neurogenesis; D009474:Neurons / Q000502:physiology* / Q000648:ultrastructure; D000091042:Reelin Protein; D012697:Serine Endopeptidases / Q000235:genetics / Q000502:physiology*; D000072760:Single Molecule Imaging; D051176:beta Catenin / Q000378:metabolism*
C495267:CTNNB1 protein, mouse; D015820:Cadherins; C489083:Cdh2 protein, mouse; D015816:Cell Adhesion Molecules, Neuronal; D016326:Extracellular Matrix Proteins; D009419:Nerve Tissue Proteins; D000091042:Reelin Protein; D051176:beta Catenin; C000717128:Reln protein, mouse; D012697:Serine Endopeptidases
N-cadherin; Reelin; aggregation; corticogenesis; neuronal migration