Diet-induced obesity regulates the galanin-mediated signaling cascade in the adipose tissue of mice.
Galanin is a neuropeptide that regulates the food intake, neurogenesis, memory, and gut secretion. This study was conducted to evaluate the high-fat diet (HFD)-induced regulation of the galanin receptors (GalRs) and the associated signaling molecules in the adipose tissues of mice. Twenty C57BL/6J mice were given either an HFD or a normal diet for 12 wk. The results of the semiquantitative RT-PCR analyses indicated that the HFD upregulated the expression of GalR1, GalR2, GalR3, resistance to audiogenic seizures, peroxisome proliferator-activated receptorgamma2, adipocyte protein 2, and protein kinase Cdelta and downregulated the expression of peroxisome proliferative activated receptor gamma coactivator 1alpha and uncoupling protein 1 in the adipose tissues. The immunoblot results showed that the protein levels of peroxisome proliferator-activated receptorgamma2 and adipocyte protein 2, and the phosphorylation of c-Raf and extracellular signal-regulated kinase 1/2 were increased, while the phosphorylation of cyclic adenosine monophosphate-responsive element-binding protein, which regulates peroxisome proliferative activated receptor gamma coactivator 1alpha and uncoupling protein 1, was decreased in the epididymal adipose tissues of the HFD-fed mice. These results suggest the possible association of the galanin-mediated signaling pathways in the manifestation of the HFD-induced activation of adipogenesis along with the suppression of thermogenesis in the adipose tissues of mice.
Kim
Ahreum
A
Department of Food and Nutrition, Brain Korea 21 Project, Yonsei University, Seoul, South Korea.
Park
Taesun
T
D041721:3T3-L1 Cells; D050156:Adipogenesis; D000818:Animals; D004041:Dietary Fats / Q000008:administration & dosage; D050556:Fatty Acid-Binding Proteins / Q000235:genetics / Q000378:metabolism; D019004:Galanin / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D050152:Intra-Abdominal Fat / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018482:Muscle, Skeletal / Q000378:metabolism; D009765:Obesity / Q000378:metabolism*; D047495:PPAR gamma / Q000235:genetics / Q000378:metabolism; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D044088:Receptors, Galanin / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D050151:Subcutaneous Fat / Q000378:metabolism*
D004041:Dietary Fats; C493411:Fabp4 protein, mouse; D050556:Fatty Acid-Binding Proteins; D047495:PPAR gamma; D020033:Protein Isoforms; D012333:RNA, Messenger; D044088:Receptors, Galanin; D019004:Galanin; C087857:protein kinase C gamma; D011493:Protein Kinase C