Localization of insulinoma associated protein 2, IA-2 in mouse neuroendocrine tissues using two novel monoclonal antibodies.
OBJECTIVE
Insulinoma-associated protein 2 (IA-2) is a member of the protein tyrosine phosphatase family that is localized on the insulin granule membrane. IA-2 is also well known as one of the major autoantigens in Type 1 diabetes mellitus. IA-2 gene deficient mice were recently established and showed abnormalities in insulin secretion. Thus, detailed localization of IA-2 was studied using wild-type and IA-2 gene deficient mice.


METHODS
To localize IA-2 expression in mouse neuroendocrine tissues, monoclonal antibodies were generated against IA-2 and western blot and immunohistochemical analyses were carried out in IA-2(+/+) mice. IA-2(-/-) mice served as a negative control.


RESULTS
Western blot analysis revealed that the 65 kDa form of IA-2 was observed in the cerebrum, cerebellum, medulla oblongata, pancreas, adrenal gland, pituitary gland, muscular layers of the stomach, small intestine, and colon. By immunohistochemical analysis, IA-2 was produced in endocrine cells in pancreatic islets, adrenal medullary cells, thyroid C-cells, Kulchitsky cells, and anterior, intermediate, and posterior pituitary cells. In addition, IA-2 was found in somatostatin-producing D-cells and other small populations of cells were scattered in the gastric corpus. IA-2 expression in neurites was confirmed by the immunostaining of IA-2 using primary cultured neurons from the small intestine and nerve growth factor (NGF)-differentiated PC12 cells.


CONCLUSIONS
The IA-2 distribution in peripheral neurons appeared more intensely in neurites rather than in the cell bodies.
Takeyama
Natsumi
N
Department of Molecular Immunology, School of Agricultural and Life Sciences, University of Tokyo, Bunkyo-ku, Tokyo, Japan.
Ano
Yasuhisa
Y
Wu
Guoying
G
Kubota
Nobuyoshi
N
Saeki
Keiichi
K
Sakudo
Akikazu
A
Momotani
Eiichi
E
Sugiura
Katsuaki
K
Yukawa
Masayoshi
M
Onodera
Takashi
T
D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism*; D001921:Brain / Q000166:cytology / Q000378:metabolism; D053379:Chromogranin A / Q000378:metabolism; D041981:Gastrointestinal Tract / Q000166:cytology / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D055099:Neuroendocrine Cells / Q000166:cytology / Q000378:metabolism*; D016716:PC12 Cells; D051381:Rats; D017208:Rats, Wistar; D054635:Receptor-Like Protein Tyrosine Phosphatases, Class 8 / Q000235:genetics / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D053379:Chromogranin A; D054635:Receptor-Like Protein Tyrosine Phosphatases, Class 8