Poster Presentation ANZOS-Breakthrough Discoveries Joint Annual Scientific Meeting 2018

Expression of nutrient sensing mechanisms in the mouse stomach (#233)

Maria Nunez-Salces 1 2 3 , Hui Li 1 2 3 , Christine Feinle-Bisset 1 3 , Amanda Page 1 2 3
  1. Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia
  2. Centre for Nutrition and Gastrointestinal Disease Research, South Australian Health & Medical Research Institute (SAHMRI), Adelaide, SA, Australia
  3. NHMRC Centre of Research Excellence in Translating Nutritional Science to Good Health, University of Adelaide, Adelaide, SA, Australia

Background and aim: The ability of the gastrointestinal tract to detect nutrients is critical for the regulation of a range of physiological responses, including digestion and food intake. The detection of nutrients typically involves the interaction of a nutrient with a particular chemosensor. Limited information is available on the nutrient sensing capability of the stomach, with most of the studies primarily focusing the small intestine. Therefore, we investigated expression of nutrient sensors in the mouse stomach.

Methods: QRT-PCR was performed to investigate expression of nutrient sensors within the glandular regions (corpus and antrum) of the stomach of 8 week old male C57BL/6 mice. Duodenal samples were included as reference tissue. Target genes included sensors for the detection of protein digestion products (GPR93, CaSR and MGluR4), fatty acids (FFAR2, FFAR4 and CD36), the sweet and umami taste receptor subunit (T1R3), and cellular components involved in the transduction of the nutrient sensing signal (GNAT2, GNAT3 and TRPM5). Housekeeper genes were β2-microglobulin, peptidylprolyl isomerase A and hypoxanthine guanine phosphoribosyltransferase. 

Results: Within the stomach, CaSR, GPR93, FFAR2, FFAR4, T1R3, TRPM5, and GNAT3 were identified with higher mRNA expression observed in the antrum than corpus. CD36 and GNAT2 were also present, with comparable expression in the antrum and corpus. No significant differences were observed between the antrum and duodenum for GPR93, MGluR4, FFAR4, T1R3 and TRPM5. Moreover, the expression of CaSR, FFAR2, GNAT3 and CD36 was higher in the corpus and antrum compared with the duodenum.

Conclusion: The mouse stomach expresses the genetic tools for the detection of nutrients, especially the digestion products of protein and fat. Furthermore, the level of expression is region-specific, with most targets presenting higher mRNA expression in the antrum than corpus. These gastric chemosensors may play a role in the modulation of gastrointestinal motility, digestive secretions and food intake.