Expression of Secretogranin III in Chicken Endocrine Cells: Its Relevance to the Secretory Granule Properties of Peptide Prohormone Processing and Bioactive Amine Content |
| |
Authors: | Hiroshi Gomi Satomi Morikawa Naoki Shinmura Hiroaki Moki Tadashi Yasui Azuma Tsukise Seiji Torii Tsuyoshi Watanabe Yoshinori Maeda Masahiro Hosaka |
| |
Institution: | Department of Veterinary Anatomy, College of Bioresource Sciences, Nihon University, Fujisawa, Japan (HG, SM, NS, HM, TY, AT);Laboratory of Secretion Biology, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Japan (ST);Department of Microscopic Anatomy and Cell Biology, Asahikawa Medical College, Asahikawa, Japan (TW);Laboratory of Molecular Life Sciences, Department of Biotechnology, Akita Prefectural University, Akita, Japan (YM, MH) |
| |
Abstract: | The expression of secretogranin III (SgIII) in chicken endocrine cells has not been investigated. There is limited data available for the immunohistochemical localization of SgIII in the brain, pituitary, and pancreatic islets of humans and rodents. In the present study, we used immunoblotting to reveal the similarities between the expression patterns of SgIII in the common endocrine glands of chickens and rats. The protein–protein interactions between SgIII and chromogranin A (CgA) mediate the sorting of CgA/prohormone core aggregates to the secretory granule membrane. We examined these interactions using co-immunoprecipitation in chicken endocrine tissues. Using immunohistochemistry, we also examined the expression of SgIII in a wide range of chicken endocrine glands and gastrointestinal endocrine cells (GECs). SgIII was expressed in the pituitary, pineal, adrenal (medullary parts), parathyroid, and ultimobranchial glands, but not in the thyroid gland. It was also expressed in GECs of the stomach (proventriculus and gizzard), small and large intestines, and pancreatic islet cells. These SgIII-expressing cells co-expressed serotonin, somatostatin, gastric inhibitory polypeptide, glucagon-like peptide-1, glucagon, or insulin. These results suggest that SgIII is expressed in the endocrine cells that secrete peptide hormones, which mature via the intragranular enzymatic processing of prohormones and physiologically active amines in chickens. |
| |
Keywords: | adrenal medulla chicken endocrine system chromogranin gastrointestinal endocrine cells pancreatic islets proteolytic processing prohormone secretogranin secretory granules ultimobranchial glands |
|
|