Impaired hepatic glucose metabolism and liver-α-cell axis in mice with liver-specific ablation of the Hepatocyte Nuclear Factor 4α (Hnf4a) gene.
Glucagon
Glucagon receptor
Glucose
Hepatocyte nuclear factor 4
Liver
Liver-α-cell axis
Non-alcoholic fatty liver disease
Journal
Metabolism: clinical and experimental
ISSN: 1532-8600
Titre abrégé: Metabolism
Pays: United States
ID NLM: 0375267
Informations de publication
Date de publication:
02 2023
02 2023
Historique:
received:
24
06
2022
revised:
18
11
2022
accepted:
25
11
2022
pubmed:
5
12
2022
medline:
31
12
2022
entrez:
4
12
2022
Statut:
ppublish
Résumé
Hnf4a gene ablation in mouse liver causes hepatic steatosis, perturbs HDL structure and function and affects many pathways and genes related to glucose metabolism. Our aim here was to investigate the role of liver HNF4A in glucose homeostasis. Serum and tissue samples were obtained from Alb-Cre;Hnf4a H4LivKO mice presented lower blood levels of fasting glucose, improved glucose tolerance, increased serum lactate levels and reduced response to glucagon challenge compared to their control littermates. Insulin signaling in the liver was reduced despite the increase in serum insulin levels. H4LivKO mice showed altered expression of genes involved in glycolysis, gluconeogenesis and glycogen metabolism in the liver. The expression of the gene encoding the glucagon receptor (Gcgr) was markedly reduced in H4LivKO liver and chromatin immunoprecipitation assays revealed specific and strong binding of HNF4A to the Gcgr promoter. H4LivKO mice presented increased amino acid concentration in the serum, α-cell hyperplasia and a dramatic increase in glucagon levels suggesting an impairment of the liver-α-cell axis. Glucose administration in the drinking water of H4LivKO mice resulted in an impressive extension of survival. The expression of several genes related to non-alcoholic fatty liver disease progression to more severe liver pathologies, including Mcp1, Gdf15, Igfbp-1 and Hmox1, was increased in H4LivKO mice as early as 6 weeks of age and this increased expression was sustained until the endpoint of the study. Our results reveal a novel role of liver HNF4A in controlling blood glucose levels via regulation of glucagon signaling. In combination with the steatotic phenotype, our results suggest that H4LivKO mice could serve as a valuable model for studying glucose homeostasis in the context of non-alcoholic fatty liver disease.
Sections du résumé
BACKGROUND
Hnf4a gene ablation in mouse liver causes hepatic steatosis, perturbs HDL structure and function and affects many pathways and genes related to glucose metabolism. Our aim here was to investigate the role of liver HNF4A in glucose homeostasis.
METHODS
Serum and tissue samples were obtained from Alb-Cre;Hnf4a
RESULTS
H4LivKO mice presented lower blood levels of fasting glucose, improved glucose tolerance, increased serum lactate levels and reduced response to glucagon challenge compared to their control littermates. Insulin signaling in the liver was reduced despite the increase in serum insulin levels. H4LivKO mice showed altered expression of genes involved in glycolysis, gluconeogenesis and glycogen metabolism in the liver. The expression of the gene encoding the glucagon receptor (Gcgr) was markedly reduced in H4LivKO liver and chromatin immunoprecipitation assays revealed specific and strong binding of HNF4A to the Gcgr promoter. H4LivKO mice presented increased amino acid concentration in the serum, α-cell hyperplasia and a dramatic increase in glucagon levels suggesting an impairment of the liver-α-cell axis. Glucose administration in the drinking water of H4LivKO mice resulted in an impressive extension of survival. The expression of several genes related to non-alcoholic fatty liver disease progression to more severe liver pathologies, including Mcp1, Gdf15, Igfbp-1 and Hmox1, was increased in H4LivKO mice as early as 6 weeks of age and this increased expression was sustained until the endpoint of the study.
CONCLUSIONS
Our results reveal a novel role of liver HNF4A in controlling blood glucose levels via regulation of glucagon signaling. In combination with the steatotic phenotype, our results suggest that H4LivKO mice could serve as a valuable model for studying glucose homeostasis in the context of non-alcoholic fatty liver disease.
Identifiants
pubmed: 36464036
pii: S0026-0495(22)00249-9
doi: 10.1016/j.metabol.2022.155371
pii:
doi:
Substances chimiques
Glucose
IY9XDZ35W2
Glucagon
9007-92-5
Insulin
0
Hepatocyte Nuclear Factors
0
Hnf4a protein, mouse
0
Hepatocyte Nuclear Factor 4
0
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
155371Informations de copyright
Copyright © 2022 Elsevier Inc. All rights reserved.
Déclaration de conflit d'intérêts
Declaration of competing interest The authors declare no competing interests.