Differences in mRNA expression of adipocyte-derived factors in response to fasting, refeeding and leptin

• Published in: Biochimica et biophysica acta 2004-07, Vol.1683 (1), p.101-109
• Main Authors: Bertile, Fabrice, Raclot, Thierry
• Format: Article
• Language: English
• Subjects: Adiponectin; Adiponutrin; Adipose Tissue; Adipose Tissue - metabolism; Animals; Biodiversity; Eating; Epididymis; Fasting; Hormones, Ectopic; Hormones, Ectopic - genetics; Hormones, Ectopic - metabolism; Insulin-Like Growth Factor I; Insulin-Like Growth Factor I - genetics; Insulin-Like Growth Factor I - metabolism; Intercellular Signaling Peptides and Proteins; Leptin; Leptin - pharmacology; Life Sciences; Male; Membrane Proteins; Membrane Proteins - genetics; Membrane Proteins - metabolism; mRNA level; Nitrogen; Nitrogen - metabolism; Populations and Evolution; Prolonged food deprivation; Proteins; Proteins - genetics; Proteins - metabolism; Rats; Rats, Sprague-Dawley; Resistin; RNA, Messenger; RNA, Messenger - metabolism; Urea; Urea - urine
• ISSN: 1388-1981; 0006-3002; 0167-4889; 1879-2618
• DOI: 10.1016/j.bbalip.2004.05.001

The present study examines whether and to what extent the profiles of adipose-derived factors are altered in epididymal and subcutaneous adipose tissues of long-term fasted/refed and of fasted rats treated by recombinant leptin. Fasting was characterized by three successive metabolic phases. Minor differences in the time-course and magnitude of response were detected between the two adipose sites. Leptin, adiponectin, resistin, adiponutrin, and insulin-like growth factor-1 (IGF-1) gene expressions differentially decreased according to the fasting duration. mRNA levels reached a minimum in late fasting for these secreted factors, being decreased by 60–90% for adiponectin, resistin, and IGF-1, 95–98% for leptin and by 100% for adiponutrin. Refeeding partially or totally restored their mRNA expression in epididymal adipose. Expression levels of apolipoprotein E (ApoE), angiotensinogen (AGT), adipsin and macrophage migration inhibitory factor (MIF) were either unchanged or slightly affected. In leptin-treated rats, leptin mRNA concentrations were significantly decreased in phase 2 of fasting (by 85%) from levels in control phosphate-buffered saline (PBS)-treated rats in both tissues. Leptin treatment also decreased resistin mRNA levels (by 78% in P2L and 63% in P3L relative to control groups) in subcutaneous adipose. These data suggest that adiponectin, resistin, adiponutrin, and IGF-1 could be involved in overall energy homeostasis during prolonged fasting, as leptin is. The mechanisms that underlie the expressions of these adipose-secreted factors remain to be determined.