Distribution of nesfatin-1/NUCB2 in the digestive system of humans and rodents

Abstract

Objective To investigate the regional distribution and morphological features of nesfatin-1/NUCB2 in digestive system of the humans, Sprague-Dawley (SD) rats and the institute of cancer research (ICR) mice, so as to lay the foundation for further study of its functions in the digestive system. Methods The specimens were obtained from SD rats and ICR mice as well as 20 patients with digestive disease, who were admitted to the First hospital affiliated to Nanjing Medical University and receired surgercal treatment. The specimens from patients with malignant tumors were obtained 5 cm apart from cancerous tissues and from patients with benign tumors were obtained near the focus. The resected tissues included pancreas, stomach, duodenum, esophagus, liver, small intestine or colon. The distribution of nesfatin-1/NUCB2 was examined with immunohistochemical (IHC) staining and its protein level in each organ was measured using Western blotting. Results The immuinohistocemical study revealed the similar distribution pattern of nesfatin-1/NUCB2 in the digestive system of the patients, SD rats and ICR mice. Nesfatin-1/NUCB2 was found to localize in the center of the pancreatic islets, the lower 1/3 to 1/2 of the gastric mucosal glands, as well as the submucosa of the duodenum. Western blotting examination showed the expression of NUCB2 in all tissues from patients, SD rats and ICR mice, whereas the protein level of the nesfatin-1/NUCB2 was higher in pancreas (0.84±0.03, 0. 84±0.05 and 0. 84±0.04, respectively), stomach (0.86±0.06,0.81±0.02 and 0. 78±0.02, respectively) or duodenum (0.79±0.09,0. 79±0.04 and 0.78±0.05)than that in esophagus (0.43±0.04,0.44 ± 0.02 and 0.47 ± 0.06, respectively), liver (0.42±0.01,0.44±0.04 and 0.43 ± 0.01, objectively), small intestine (0.32±0.04,0. 32 ± 0. 04 and 0.34 ±0.04, respectively) or colon (0. 29±0.01,0.32±0.03 and 0. 28±0.03, respectively)(all P values=0. 000). Conclusion Nesfatin-1/NUCB2 is widely expressed in the pancreatic islets, gastric mucosal glands and duodenum of the patients, SD rats and ICR mice, which indicates that nesfatin-1/NUCB2 may be involved in the regulation of food intake, carbohydrate metabolism and gastrointestinal motility. Key words: Nesfatin-1 protein; Nucleobindin2 protein; Pancreas; Stomach; Duodenum; Brunner glands; Immunohistochemistry