title: Propionate induces mRNA expression of gluconeogenic genes in bovine calf hepatocytes.
abstract: Hepatocytes monolayers from neonatal calves were used to determine the responses of the cytosolic phosphoenolpyruvate carboxykinase (PCK1) mRNA expression to propionate and direct hormonal cues including cyclic AMP (cAMP), dexamethasone, and insulin. The responses of other key gluconeogenic genes, including mitochondrial phosphoenolpyruvate carboxykinase (PCK2), pyruvate carboxylase (PC), and glucose-6-phosphotase (G6PC), were also measured. Expression of PCK1 was linearly induced with increasing propionate concentrations in media and 2.5 mM propionate increased PCK1 mRNA at 3 and 6h of incubation; however, the induction disappeared at 12 and 24 h. The induction of PCK1 mRNA by propionate was mimicked by 1 mM cAMP, or in combination with 5 µM dexamethasone, but not by dexamethasone alone. The induction of PCK1 mRNA by propionate or cAMP was eliminated by addition of 100 nM insulin. Additionally, expression of PCK2 and PC mRNA was also induced by propionate in a concentration-dependent manner. Consistent with PCK1, propionate-stimulated PCK2 and PC mRNA expression was inhibited by insulin. Expression of G6PC mRNA was neither affected by propionate nor cAMP, dexamethasone, insulin, or their combinations. These findings demonstrate that propionate can directly regulate its own metabolism in bovine calf hepatocytes through upregulation of PCK1, PCK2, and PC mRNA expression.
authors.affiliation: Department of Animal Sciences, Purdue University, West Lafayette 47907.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Animal Sciences, Purdue University, West Lafayette 47907.
authors.forename: Stephanie L
authors.initials: SL
authors.lastname: Koser
authors.affiliation: Department of Animal Sciences, Purdue University, West Lafayette 47907. Electronic address: sdonkin@purdue.edu.
authors.forename: Shawn S
authors.initials: SS
authors.lastname: Donkin
mesh_terms: D000818:Animals; D002417:Cattle; D005943:Gluconeogenesis / Q000235:genetics; D022781:Hepatocytes / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D010729:Phosphoenolpyruvate Carboxykinase (GTP) / Q000235:genetics*; D011422:Propionates / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D011422:Propionates; D012333:RNA, Messenger; D010729:Phosphoenolpyruvate Carboxykinase (GTP)
keywords: PCK1; gluconeogenesis; hormonal regulation