The following is a summary of “Expression of Neurotensin and Its Receptors Along the Intestinal Tract in Type 2 Diabetes Patients and Healthy Controls,” published in the September 2023 issue of Endocrinology by Gilliam-Vigh, et al.
Enteroendocrine N cells secrete neurotensin (NTS), a hormone associated with reduced food intake and potential insulin release in rodents. In humans, the post-meal response of NTS increases following Roux-en-Y gastric bypass surgery, linking this hormone to the glucose- and weight-lowering effects of these procedures. For a study, researchers sought to investigate N cell density and mucosal messenger RNA (mRNA) expression profiles of NTS and NTS receptors in patients with type 2 diabetes (T2D) and matched healthy individuals.
Biopsies were obtained from 12 T2D patients and 12 healthy controls using double-balloon enteroscopy. The biopsies were collected from the entire length of the small intestine at 30 cm intervals and from seven specific locations in the large intestine. The biopsies were then analyzed using immunohistochemistry and mRNA sequencing.
The study revealed that N cell density and NTS mRNA expression gradually increased from the duodenum to the ileum in the small intestine, with minimal NTS-positive cells and NTS mRNA expression in the large intestine. While NTS receptor 1 and 2 mRNA expression were not detected, sortilin, a neuropeptide receptor to which NTS binds, was consistently expressed throughout the intestines. Although patients with T2D showed slightly lower levels of NTS-positive cells and mRNA expression compared to healthy controls, these differences were not statistically significant after adjusting for multiple comparisons.
The unique mapping of N cell density and NTS expression in the intestines demonstrated a gradual increase from the proximal to the distal end of the small intestine. There were no significant differences between patients with T2D and healthy individuals. Furthermore, negligible N-cells and NTS mRNA expression were observed in the large intestine. Sortilin was expressed consistently throughout the intestines in both groups, while NTS receptor 1 or 2 mRNA expression was not detected.