Yin and Yang: the Gastric X/A-like Cell as Possible Dual Regulator of Food Intake

Ingestion of food affects secretion of hormones from enteroendocrine cells located in the gastrointestinal mucosa. These hormones are involved in the regulation of various gastrointestinal functions including the control of food intake. One cell in the stomach, the X/A-like has received much attention over the past years due to the production of ghrelin. Until now, ghrelin is the only known orexigenic hormone that is peripherally produced and centrally acting to stimulate food intake. Subsequently, additional peptide products of this cell have been described including desacyl ghrelin, obestatin and nesfatin-1. Desacyl ghrelin seems to be involved in the regulation of food intake as well and could play a counter-balancing role of ghrelin's orexigenic effect. In contrast, the initially proposed anorexigenic action of obestatin did not hold true and therefore the involvement of this peptide in the regulation of feeding is questionable. Lastly, the identification of nesfatin-1 in the same cell in different vesicles than ghrelin extended the function of this cell type to the inhibition of feeding. Therefore, this X/A-like cell could play a unique role by encompassing yin and yang properties to mediate not only hunger but also satiety.

Distribution of nesfatin-1/NUCB2 in the digestive system of humans and rodents / 中华消化杂志

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.