Regulation of adult neural progenitor cells by Galectin-1/beta1 Integrin interaction.
Neural stem cells (NSCs) proliferate and generate new neurons in the adult brain. A carbohydrate-binding protein (lectin), Galectin-1, is expressed in the NSCs in the subependymal zone (SEZ) of the adult mouse brain. The infusion and knockout of Galectin-1 in the SEZ results in an increase and decrease, respectively, of NSCs and subsequently born progenitor cells. The molecular mechanism of this effect, however, has been unknown. Previous studies outside the brain suggest that Galectin-1 binds to a carbohydrate structure of beta1 Integrin and modulates cell adhesion. Here, we studied the functional interaction between Galectin-1 and beta1 Integrin in the adult mouse SEZ. Beta1 Integrin was purified from adult SEZ tissue by binding to a Galectin-1 affinity column, and this binding depended on Galectin-1's carbohydrate-binding activity. In adult brain sections, Galectin-1-binding activity was detected on beta1 Integrin-expressing cells in the SEZ. Furthermore, in the adult SEZ, the simultaneous infusion of a beta1 Integrin-neutralizing antibody with Galectin-1 protein reversed the increasing effect of Galectin-1 on the number of adult neural progenitor cells (NPCs). Finally, intact beta1 Integrin was required for Galectin-1's function in NPC adhesion in vitro. These results suggest that the interaction between beta1 Integrin and Galectin-1 plays an important role in regulating the number of adult NPCs through mechanisms including cell adhesion.
Sakaguchi
Masanori
M
Department of Physiology, Keio University School of Medicine, Tokyo, Japan.
Imaizumi
Yoichi
Y
Shingo
Tetsuro
T
Tada
Hirobumi
H
Hayama
Ko
K
Yamada
Osamu
O
Morishita
Tsuyoshi
T
Kadoya
Toshihiko
T
Uchiyama
Noboru
N
Shimazaki
Takuya
T
Kuno
Atsushi
A
Poirier
Françoise
F
Hirabayashi
Jun
J
Sawamoto
Kazunobu
K
Okano
Hideyuki
H
D053687:Adult Stem Cells / Q000502:physiology*; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism; D001921:Brain / Q000166:cytology; D001973:Bromodeoxyuridine / Q000378:metabolism; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology; D002846:Chromatography, Affinity / Q000379:methods; D037483:Galectin 1 / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000235:genetics; D019012:Integrin beta1 / Q000235:genetics / Q000378:metabolism*; D007785:Lactose / Q000494:pharmacology; D051379:Mice; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D011485:Protein Binding / Q000187:drug effects / Q000502:physiology; D013549:Sweetening Agents / Q000494:pharmacology; D013997:Time Factors
D000906:Antibodies; D037483:Galectin 1; D019012:Integrin beta1; D013549:Sweetening Agents; D049452:Green Fluorescent Proteins; D001973:Bromodeoxyuridine; D007785:Lactose