Identification and Characterization of Nesfatin-1 Immunoreactivity in Endocrine Cell Types of the Rat Gastric Oxyntic Mucosa

• Published in: Endocrinology (Philadelphia) Vol. 150; no. 1; pp. 232 - 238
• Main Authors: Stengel, Andreas, Goebel, Miriam, Yakubov, Iskandar, Wang, Lixin, Witcher, Derrick, Coskun, Tamer, Taché, Yvette, Sachs, George, Lambrecht, Nils W. G
• Format: Journal Article
• Language: English
• Published: Chevy Chase, MD Endocrine Society 01.01.2009; The Endocrine Society
• Subjects: Animals; Biological and medical sciences; Calcium-Binding Proteins - genetics; DNA-Binding Proteins - genetics; Energy Intake; Fundamental and applied biological sciences. Psychology; Gastric Mucosa - cytology; Ghrelin - metabolism; Histidine Decarboxylase - metabolism; Immunohistochemistry; Male; Nerve Tissue Proteins - genetics; Nerve Tissue Proteins - metabolism; Oligonucleotide Array Sequence Analysis; Pancreas - cytology; Parietal Cells, Gastric - cytology; Pituitary Gland - cytology; Rats; Rats, Sprague-Dawley; Reverse Transcriptase Polymerase Chain Reaction; RNA - genetics; RNA - isolation & purification; Somatostatin - metabolism; Vertebrates: endocrinology; Weight Gain; Characterization; Stomach; Vertebrata; Mammalia; Endocrine cell; Rat; Digestive system; Animal; Mucosa; Rodentia
• ISSN: 0013-7227; 1945-7170
• DOI: 10.1210/en.2008-0747

Hypothalamic nesfatin-1, derived from the nucleobindin2 (NUCB2) precursor, inhibits nocturnal food intake and body weight gain in rats. Nesfatin-1 is able to cross the blood-brain barrier, suggesting a peripheral source of nesfatin-1. Many centrally acting food intake regulatory neuropeptides are also produced in the periphery, especially in the gastrointestinal tract. Therefore, we investigated the gene expression of NUCB2 and distribution of nesfatin-1-immunoreactive cells in the stomach. Microarray mRNA expression profiles in purified small endocrine cells of the gastric mucosa substantiated by quantitative RT-PCR showed significantly higher NUCB2 mRNA expression compared with brain and heart. Western blot confirmed the expression of NUCB2 protein and its transport into a secretory soluble fraction of gastric mucosal endocrine cell homogenates. Immunohistochemical colabeling for nesfatin-1 and ghrelin, histidine decarboxylase, or somatostatin revealed two subtypes of nesfatin-1-positive endocrine cells. Cells in the midportion of the glands coexpressed nesfatin-1 and ghrelin, whereas few cells in the glandular base coexpressed nesfatin-1 and somatostatin or histidine decarboxylase. High-resolution three-dimensional volume imaging revealed two separate populations of intracytoplasmic vesicles in these cells, one containing nesfatin-1 and the other ghrelin immunoreactivity. Microarray rat genome expression data of NUCB2 in small gastric endocrine cells confirmed by quantitative RT-PCR showed significant down-regulation of NUCB2 after 24 h fasting. In summary, NUCB2 mRNA expression as well as protein content is present in a specific subset of gastric endocrine cells, most of which coexpress ghrelin. NUCB2 gene expression is significantly regulated by nutritional status, suggesting a regulatory role of peripheral nesfatin-1 in energy homeostasis. Nesfatin-1/nucleobindin 2 is co-expressed in gastric ghrelin-containing X/A-like cells, suggesting the release of orexigenic and anorexigenic peptides from the same endocrine cells regulating food intake.