Mutation in the neural cell adhesion molecule interferes with the differentiation of anterior pituitary secretory cells.
The neural cell adhesion molecule (NCAM) and its polysialylated isoform (PSA-NCAM) have been shown to influence the proliferation, differentiation and survival of different cell types. Here, we report the pattern of expression of NCAM and PSA-NCAM in the anterior lobe (AL) of the pituitary gland of the adult mouse. We demonstrate that the majority of cells express NCAM, while PSA-NCAM is retained mostly on corticotropes. Analysis of bromodeoxyuridine (BrdU) incorporation shows that the presence of PSA-NCAM on corticotropes is not related to proliferation but most likely to their functional properties. We subsequently analyzed defects induced by NCAM deficiency in adult NCAM knockout mice. In these mice, all secretory cell types in the AL are present and their distribution within the gland is similar to that in wild-type mice. However, proliferation of AL cells is significantly increased. In particular, more BrdU-positive cells are detected among somatotropes and mammotropes in NCAM-deficient mice. In addition, the percentages of secretory cells are changed: somatotropes are more numerous while the number of corticotropes is reduced. These data demonstrate the involvement of NCAM in the proper generation and/or maintenance of the different cell populations in the AL and suggest the importance of PSA in corticotrope functioning.
Gubkina
O
O
Laboratoire de Génétique et Physiologie de Développement, CNRS 6545, Institut de Biologie de Développement de Marseille, Parc Scientifique de Luminy, F-13288 Marseille Cedex 9, France.
Cremer
H
H
Rougon
G
G
D000818:Animals; D002452:Cell Count; D002454:Cell Differentiation / Q000502:physiology; D013006:Growth Hormone / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009154:Mutation / Q000502:physiology*; D039842:Neural Cell Adhesion Molecule L1; D019006:Neural Cell Adhesion Molecules / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism; D010903:Pituitary Gland, Anterior / Q000166:cytology* / Q000378:metabolism*; D011388:Prolactin / Q000378:metabolism; D012016:Reference Values; D012794:Sialic Acids / Q000378:metabolism
D039842:Neural Cell Adhesion Molecule L1; D019006:Neural Cell Adhesion Molecules; D012794:Sialic Acids; C103469:polysialyl neural cell adhesion molecule; D011388:Prolactin; D013006:Growth Hormone