Oral Presentation ANZOS-ASLM-ICCR 2019

The expression of nutrient-sensing components in the mouse stomach and the gastric ghrelin cell (#26)

Maria Nunez-Salces 1 2 3 , Hui Li 1 2 3 , Christine Feinle-Bisset 3 , Amanda Page 1 2 3
  1. Vagal Afferent Research Group, Adelaide Medical School, University of Adelaide, Adelaide, SA , Australia
  2. Nutrition, Diabetes and Metabolism, Lifelong Health Theme, 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 physiological responses, such as the secretion of gut hormones, associated with the regulation of food intake and postprandial blood glucose control. The detection of nutrients involves the interaction of nutrients with specific chemosensors. Limited information is available on the expression of nutrient chemosensors in the stomach. This study aimed to investigate the nutrient-sensing repertoire of the mouse stomach with particular emphasis on cells containing the “hunger” hormone, ghrelin.

Methods: QRT-PCR was used to determine mRNA levels of nutrient chemosensors (protein: GPR93, CaSR, MGluR4; fatty acids: CD36, FFAR2&4; sweet/umami: T1R3), taste-transduction components (TRPM5, GNAT2&3), ghrelin and ghrelin-processing enzymes (PC1/3, GOAT) in the gastric corpus and antrum of eight-week-old male C57BL/6 mice. Immunohistochemistry was performed to assess the protein expression of chemosensors (GPR93, T1R3, CD36 and FFAR4), and their co-localisation with ghrelin in the antrum and corpus.

Results: The majority of QRT-PCR targets presented higher mRNA levels in the antrum than in the corpus, with the exception of CD36, GNAT2, ghrelin and GOAT. Similar regional distribution was observed at the protein level. At least 60% of ghrelin-positive cells expressed T1R3 and FFAR4, and over 80% expressed GPR93 and CD36.

Conclusion: The cellular mechanisms for the detection of nutrients are expressed in a region-specific manner in the mouse stomach and gastric ghrelin cells. These gastric nutrient chemosensors may play a role in the modulation of gastrointestinal responses, such as the inhibition of ghrelin secretion following food intake.