Developmental regulation of the intestinal FGF19 system in domestic pigs

Fibroblast growth factor-19 (FGF19) is an emerging endocrine factor involved in the regulation of bile acid homeostasis and energy metabolism in rodents and humans. In pigs, however, the FGF19 system remains largely unexplored. This study was designed to investigate the developmental regulation of the FGF19 system in domestic pigs. Samples of intestinal sections, liver, and plasma were collected from 24 pigs (n = 6) at four developmental stages (birth, pre-weaning, post-weaning, and adulthood). In the intestine, expression of the farnesoid X receptor (FXR) and FGF19 showed a congruent time- and region-dependent regulation, beginning soon after birth to achieve maximal expression in ileum during adulthood. The same temporal pattern was followed by the circulating concentration of FGF19 and these changes were accompanied by a time-related increase in the ileal proportion of bile acids that potently activate FXR. Conversely, genes belonging to the FGF19 signaling machinery achieved maximal expression in the ...