Is Altered Expression of Hepatic Insulin-Related Genes in Growth Hormone Receptor Knockout Mice Due to GH Resistance or a Difference in Biological Life Spans?
AUTOR(ES)
Panici, Jacob A.
FONTE
Oxford University Press
RESUMO
Growth hormone receptor knockout (GHRKO) mice live about 40%–55% longer than their normal (N) littermates. Previous studies of 21-month-old GHRKO and N mice showed major alterations of the hepatic expression of genes involved in insulin signaling. Differences detected at this age may have been caused by the knockout of the growth hormone receptor (GHR) or by differences in biological age between GHRKO and N mice. To address this question, we compared GHRKO and N mice at ages corresponding to the same percentage of median life span to see if the differences of gene expression persisted. Comparison of GHRKO and N mice at ∼50% of biological life span showed significant differences in hepatic expression of all 14 analyzed genes. We conclude that these changes are due to disruption of GHR gene and the consequent suppression of growth hormone signaling rather than to differences in “biological age” between mutant and normal animals sampled at the same chronological age.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2759569Documentos Relacionados
- Insulin-related genes expressed in human placenta from normal and diabetic pregnancies.
- Autocrine growth induced by the insulin-related factor in the insulin-independent teratoma cell line 1246-3A.
- Autocrine/paracrine role of insulin-related growth factors in neurogenesis: local expression and effects on cell proliferation and differentiation in retina.
- Structure and organization of four clustered genes that encode bombyxin, an insulin-related brain secretory peptide of the silkmoth Bombyx mori.
- New insights of growth hormone (GH) actions from tissue-specific GH receptor knockouts in mice