Project 2.6
Alimentary myo-inositol and low phosphate in two contrasting high-yielding laying hen strains: role of alpha-Klotho/fibroblast growth factor 23 (FGF23)
Michael Föller / Martina Feger
In mammals and birds phosphate homeostasis is tightly regulated along with calcium homeostasis by different hormones including parathyroid hormone (PTH), active vitamin D (1,25(OH)2D3) and novel regulators fibroblast growth factor 23 (FGF23)/alpha-Klotho (in the following referred to as Klotho).
The following hypotheses are being tested:
1. The myo-inositol content of feed impacts on Klotho and FGF23 production
2. Dietary deficiency of mineral phosphorus with a subsequently enhanced utilization of InsP6 has a strong effect on Klotho expression and secretion and down-regulates FGF23
3. The genetic background affects phosphate utilization of laying hens, at least in part, through Klotho and FGF23
4. Klotho and FGF23 expression are associated with Ca2+/phosphorus homeostasis as well as PTH and 1,25(OH)2D3 levels
5. The production of FGF23 and Klotho is dependent on inflammatory cytokines in laying hens
6. AMPK and insulin, mammalian regulators of FGF23, also impact on FGF23 expression in laying hens
7. Hepatic Klotho expression is related to mitochondrial haplotypes in livers from laying hens
