TY - JOUR
T1 - Localization of interleukin-18 and its receptor in somatotrophs of the bovine anterior pituitary gland
AU - Nagai, Yasuhiro
AU - Nochi, Tomonori
AU - Watanabe, Kouichi
AU - Watanabe, Keisuke
AU - Aso, Hisashi
AU - Kitazawa, Haruki
AU - Matsuzaki, Masatoshi
AU - Ohwada, Shyuichi
AU - Yamaguchi, Takahiro
N1 - Funding Information:
This work was supported by a Grant-in-Aid for Scientific Research (B) (No.13460122) from the Ministry of Education, Science and Culture of Japan.
PY - 2005/12
Y1 - 2005/12
N2 - A pro-inflammatory cytokine, interleukin 18 (IL-18), induces intracellular expression of IL-1 and the release of IL-6. IL-1 and IL-6 has been detected in anterior pituitary cells, suggesting that IL-18 is produced in anterior pituitary cells and may serve to aid immuno-endocrine regulation. In the present study, we addressed this hypothesis by investigating the intracellular localization of IL-18 and its receptor in bovine anterior pituitary gland. IL-18 mRNA and its protein were detected in the anterior pituitary gland by RT-PCR and Western blotting. In situ hybridization showed that IL-18 mRNA was expressed in the anterior pituitary cells. Immunohistochemistry of IL-18 and specific hormones revealed the presence of IL-18 in somatotrophs. Furthermore, the expression of GH mRNA in IL-18 immunoreactive cells was confirmed by immuno-laser microdissection. These results first demonstrated that somatotrophs produced IL-18. Subsequently, the distribution of the IL-18 receptor alpha (IL-18Rα) was investigated in order to understand IL-18 signaling among the anterior pituitary cells. Bovine IL-18Rα cDNA was partially sequenced and detected in the anterior pituitary gland by RT-PCR. Immunohistochemistry of IL-18Rα, IL-18 and GH showed that IL-18Rα was co-localized in IL-18 immunoreactive cells or somatotrophs. These data suggest that IL-18 acts on somatotrophs as an immuno-endocrine mediator through the autocrine pathway.
AB - A pro-inflammatory cytokine, interleukin 18 (IL-18), induces intracellular expression of IL-1 and the release of IL-6. IL-1 and IL-6 has been detected in anterior pituitary cells, suggesting that IL-18 is produced in anterior pituitary cells and may serve to aid immuno-endocrine regulation. In the present study, we addressed this hypothesis by investigating the intracellular localization of IL-18 and its receptor in bovine anterior pituitary gland. IL-18 mRNA and its protein were detected in the anterior pituitary gland by RT-PCR and Western blotting. In situ hybridization showed that IL-18 mRNA was expressed in the anterior pituitary cells. Immunohistochemistry of IL-18 and specific hormones revealed the presence of IL-18 in somatotrophs. Furthermore, the expression of GH mRNA in IL-18 immunoreactive cells was confirmed by immuno-laser microdissection. These results first demonstrated that somatotrophs produced IL-18. Subsequently, the distribution of the IL-18 receptor alpha (IL-18Rα) was investigated in order to understand IL-18 signaling among the anterior pituitary cells. Bovine IL-18Rα cDNA was partially sequenced and detected in the anterior pituitary gland by RT-PCR. Immunohistochemistry of IL-18Rα, IL-18 and GH showed that IL-18Rα was co-localized in IL-18 immunoreactive cells or somatotrophs. These data suggest that IL-18 acts on somatotrophs as an immuno-endocrine mediator through the autocrine pathway.
KW - Anterior pituitary gland
KW - Bovine
KW - Immuno-endocrine signaling
KW - Interleukin-18
KW - Interleukin-18R
KW - Somatotroph
UR - http://www.scopus.com/inward/record.url?scp=27944481233&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=27944481233&partnerID=8YFLogxK
U2 - 10.1007/s00441-005-0016-0
DO - 10.1007/s00441-005-0016-0
M3 - Article
C2 - 16001266
AN - SCOPUS:27944481233
SN - 0302-766X
VL - 322
SP - 455
EP - 462
JO - Cell and Tissue Research
JF - Cell and Tissue Research
IS - 3
ER -