Peptide YY and Proglucagon mRNA Expression Patterns and Regulation in the Gut

Abstract

YY and proglucagon mRNA expression patterns and regulation in the gut. Obesity. 2006;14:683-689. Objective: Peptide YY (PYY) and glucagon-like peptide-1 are important in the control of energy homeostasis and are both secreted from the gut in response to ingested nutrients. However, more studies are needed on nutrient regulation of their gene expression patterns in specific areas of the gut. This study detailed PYY and proglucagon (the gene that encodes glucagon-like peptide-1) gene expression patterns and regulation in the gut. We further examined the regulation of PYY and proglucagon mRNA by a diet containing fermentation-resistant starch (in vivo) and butyrate (in vitro). Research Methods and Procedures: Quantitative real time reverse transcriptase-polymerase chain reaction was used to measure PYY and proglucagon gene expression in epithelial cells collected from the duodenum, jejunum, cecum, and colon in normal Sprague-Dawley rats and in rats fed a resistant starch diet for 4 weeks. The same measurements were also performed in primary epithelial cells collected from the cecum and colon of normal rats after the cells were incubated with butyrate for 3 hours. Results: The gene expression patterns for PYY and proglucagon are similar to their peptide distribution patterns in the gut. Also, PYY and proglucagon mRNA expression were up-regulated in the cecum and colon in resistant-starch-fed rats. Butyrate increased PYY and proglucagon gene expression in a dose-dependent manner in vitro. Discussion: Our data provide evidence that the distal part of the gut has the ability to sense nutrients such as butyrate, resulting in the up-regulation of PYY and proglucagon gene expression.

Control of appetite and energy intake by SCFA: what are the potential underlying mechanisms?

“…These studies would therefore suggest that increasing the intake of fermentable dietary fibres and colonic production of SCFA would stimulate PYY and GLP-1 release. Indeed, a number of studies have reported that animals fed high doses of fermentable fibres have increased endogenous secretions of PYY and GLP-1 (55)(56)(57)(58)(59) , as well as an increased number of colonic L-cells (60) . In human subjects, it has been shown that adding 24 g of the fermentable fibre oligofructose to a test meal significantly increased GLP-1 levels in the postprandial period (61) .…”

From the gut to the peripheral tissues: the multiple effects of butyrate

“…Moreover, both GLP-1 and leptin are implicated in the pathogenesis of obesity and diabetes. Butyrate directly increases peptide YY/proglucagon gene expression in vitro (199) . Such a result is observed in vivo in RS-fed rats.…”

Enzymatically modified starch up-regulates expression of incretins and sodium-coupled monocarboxylate transporter in jejunum of growing pigs

“…The up-regulated expression of GLP1 and GIP at the jejunal mucosa of pigs fed the EMS diet might have therefore indicated greater jejunal glucose and SCFA concentrations compared with pigs fed the CON diet. Both incretins are potent antihyperglycemic hormones, inducing glucose-dependent stimulation of insulin secretion while suppressing glucagon secretion (Zhou et al, 2006;Den Besten et al, 2015b). Serum glucose was similar among pigs at the time of sampling.…”

“…In both studies, elevated SCFA concentrations either in colonic or cecal digesta could explain the up-regulation of MCT1 expression (Woodward et al, 2012;Haenen et al, 2013). Glucose and luminal SCFA induce expression of GLP1 and GIP in L-and K-cells of the intestinal mucosa (Zhou et al, 2006;Nøhr et al, 2013;Pluske, 2013). The up-regulated expression of GLP1 and GIP at the jejunal mucosa of pigs fed the EMS diet might have therefore indicated greater jejunal glucose and SCFA concentrations compared with pigs fed the CON diet.…”