Acute and chronic effects of dietary fatty acids on cholecystokinin expression, storage and secretion in enteroendocrine STC‐1 cells

Abstract

Cholecystokinin (CCK) is a peptide hormone secreted from the I-cells of the intestine and it has important physiological actions related to appetite regulation and satiety. In this study we used STC-1 cells to investigate the effects of common dietary-derived fatty acids (FAs) on I-cell secretory function and metabolism. We extend earlier studies by measuring the acute and chronic effects of 11 FAs on CCK secretion, cellular CCK content, CCK mRNA levels, cellular DNA synthesis, cellular viability and cytotoxicity. FAs were selected in order to assess the importance of chain length, degree of saturation, and double bond position and conformation. The results demonstrate that secretory responses elicited by dietary FAs are highly selective. For example, altering the conformation of a double bond from cis to trans (i.e. oleic acid versus elaidic acid) completely abolishes CCK secretion. Lauric acid appears to adversely affect I-cell metabolism and arachidonic acid suppresses DNA synthesis. Our studies reveal for the first time that conjugated linoleic acid isoforms are particularly potent CCK secretagogues, which also boost intracellular stores of CCK. These actions of conjugated linoleic acid may explain satiating actions observed in dietary intervention studies.

β-Lactoglobulin-linoleate complexes: In vitro digestion and the role of protein in fatty acid uptake

“…In order to assess the impact of samples on CCK secretion in vitro, STC-1 cell line was employed (Pasman et al, 2008, Hand et al, 2010.…”

“…The CCK assay was adapted from Hand et al (2010). Briefly, STC-1 cells were seeded into 12-well plates at a cell density of 2 × 10 6 cells/well, in complete media and incubated overnight.…”

STC-1 Cells

“…Monosaccharides (Mangel et al 1994 ), fatty acids (Hand et al 2010 ), aromatic amino acids (Cordier-Bussat 1998;Wang et al 2011 ), peptidomimetic compounds (Geraedts et al 2011 ) and bitter tastants (Miyata et al 2014 ) have all been demonstrated to dose dependently elicit CCK and GLP-1 secretion from STC-1 cells. Several studies have also reported that sucralose and other sweeteners increase CCK and GLP-1 secretion in STC-1 cells (Geraedts et al 2012 ).…”

“…For qRT-PCR, standard methods apply. Result interpretation is important as increases in mRNA levels and intracellular peptide levels may not result in corresponding increases in secretion levels of gut peptides (Hand et al 2010 ). A number of sensitive and accurate commercial immunoassays (ELISA and RIA) are available for the detection of CCK, PYY and GLP-1, although multiplexing these analytes has proved diffi cult.…”

Naringenin stimulates cholecystokinin secretion in STC-1 cells

“…Cholecystokinin (CCK), a neuropeptide, is secreted in response to intraluminal nutrients by enteroendocrine I-cells of the intestine and has important physiological actions related to appetite regulation and satiety [1]. Postprandial release of CCK is key in activation of intestinal feedback control of gastrointestinal function, comprising short-term inhibition of gastric emptying and acid secretion, stimulation of the exocrine pancreas and gallbladder, and inhibition of food intake [2].…”