title: Ontogenic pattern of nucleobindin-2/nesfatin-1 expression in the gastroenteropancreatic tissues and serum of Sprague Dawley rats.
abstract: Nesfatin-1 is a novel metabolic hormone that has glucose-responsive insulinotropic actions. Islet β-cells and gastrointestinal tissues have been reported as abundant sources of nesfatin-1 and its precursor hormone nucleobindin-2 (NUCB2). While nesfatin-1 is emerging as a multifunctional hormone, there are no reports on the developmental expression of NUCB2/nesfatin-1. The main objective of this study was to examine the ontogenic expression of NUCB2 mRNA, and NUCB2/nesfatin-1 immunoreactivity in the pancreas, stomach and duodenum, and the circulating levels NUCB2/nesfatin-1 in Sprague Dawley rats. In addition, we also determined the co-localization of NUCB2/nesfatin-1 and insulin immunoreactivity during development. NUCB2/nesfatin-1 immunoreactivity was found in the rat stomach from postnatal days 13-27. Furthermore, NUCB2/nesfatin-1 immunoreactivity was also detected in the enteroendocrine cells of the duodenum at postnatal days 13 and 27. Duodenal NUCB2 mRNA expression at postnatal day 27 was highest. Serum NUCB2/nesfatin-1 levels on embryonic day 21 and postnatal day 1 were lower than serum NUCB2/nesfatin-1 levels of adults and neonates at postnatal days 13, 20 and 27, gradually increasing with growth, suggesting an increase in its production and secretion from tissues including the gastrointestinal tract and pancreas. Our findings indicate that NUCB2/nesfatin-1 colocalizes with insulin in the islet β-cells at all developmental stages, but the percentage of colocalization varies in an age-dependent manner. These findings suggest that NUCB2/nesfatin-1 has potential age- and tissue-specific role in the developmental physiology of rats during growth.
authors.affiliation: Laboratory of Integrative Neuroendocrinology, Department of Biology, York University, Toronto, Ontario, Canada, M3J 1P3. mohanh@yorku.ca
authors.forename: Haneesha
authors.initials: H
authors.lastname: Mohan
authors.forename: Suraj
authors.initials: S
authors.lastname: Unniappan
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D015153:Blotting, Western; D002135:Calcium-Binding Proteins / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D004622:Embryo, Mammalian / Q000166:cytology / Q000378:metabolism; D019858:Enteroendocrine Cells / Q000166:cytology* / Q000378:metabolism*; D005260:Female; D041981:Gastrointestinal Tract / Q000254:growth & development* / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D005947:Glucose / Q000378:metabolism; D007124:Immunoenzyme Techniques; D007328:Insulin / Q000378:metabolism; D007515:Islets of Langerhans / Q000166:cytology / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D000080866:Nucleobindins; D010179:Pancreas / Q000166:cytology / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D002135:Calcium-Binding Proteins; D004268:DNA-Binding Proteins; D007328:Insulin; D009419:Nerve Tissue Proteins; C000630652:Nucb1 protein, rat; D000080866:Nucleobindins; D012333:RNA, Messenger; D005947:Glucose