Apelin, an APJ receptor ligand, regulates body adiposity and favors the messenger ribonucleic acid expression of uncoupling proteins in mice.
Apelin, the endogenous ligand of the APJ receptor, has been identified in a variety of tissues, including stomach, heart, skeletal muscle, and white adipose tissue. We sought to clarify the effects of apelin on body adiposity and the expression of uncoupling proteins (UCPs) in C57BL/6 mice. Treatment with ip apelin at a dose of 0.1 mumol/kg.d for 14 d decreased the weight of white adipose tissue and serum levels of insulin and triglycerides, compared with controls, without influencing food intake. Apelin treatment also decreased body adiposity and serum levels of insulin and triglycerides in obese mice fed a high-fat diet. Apelin increased the serum adiponectin level and decreased that of leptin. Additionally, apelin treatment increased mRNA expression of UCP1, a marker of peripheral energy expenditure, in brown adipose tissue (BAT) and of UCP3, a regulator of fatty acid export, in skeletal muscle. In addition, immunoblot bands and relative densities of UCP1 content in BAT were also higher in the apelin group than controls. Furthermore, apelin treatment increased body temperature and O(2) consumption and decreased the respiratory quotient. In conclusion, apelin appears to regulate adiposity and lipid metabolism in both lean and obese mice. In addition, apelin regulates insulin resistance by influencing the circulating adiponectin level, the expression of BAT UCP1, and energy expenditure in mice.
Higuchi
Keiko
K
Department of Anatomy, Biology, and Medicine, Internal Medicine 1, Faculty of Medicine, Oita University, 1-1 Idai-ga-oka, Hasama-cho, Yufu-city, Oita 879-5593, Japan. higukei@med.oita-u.ac.jp
Masaki
Takayuki
T
Gotoh
Koro
K
Chiba
Seiichi
S
Katsuragi
Isao
I
Tanaka
Katsuhiro
K
Kakuma
Tetsuya
T
Yoshimatsu
Hironobu
H
D052242:Adiponectin / Q000032:analysis / Q000097:blood; D052436:Adipose Tissue, White / Q000033:anatomy & histology / Q000737:chemistry / Q000187:drug effects; D050154:Adiposity / Q000187:drug effects* / Q000235:genetics; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects; D005951:Glucose Tolerance Test; D036341:Intercellular Signaling Peptides and Proteins / Q000494:pharmacology*; D007473:Ion Channels / Q000235:genetics* / Q000378:metabolism; D020738:Leptin / Q000032:analysis / Q000097:blood; D051379:Mice; D008810:Mice, Inbred C57BL; D024101:Mitochondrial Proteins / Q000235:genetics* / Q000378:metabolism; D009929:Organ Size / Q000187:drug effects; D012333:RNA, Messenger / Q000378:metabolism*; D013997:Time Factors; D014280:Triglycerides / Q000032:analysis; D000071256:Uncoupling Protein 1; D000071246:Uncoupling Protein 2; D000071247:Uncoupling Protein 3
D052242:Adiponectin; C499919:Adipoq protein, mouse; D036341:Intercellular Signaling Peptides and Proteins; D007473:Ion Channels; D020738:Leptin; D024101:Mitochondrial Proteins; D012333:RNA, Messenger; D014280:Triglycerides; C000604372:Ucp1 protein, mouse; C000604393:Ucp3 protein, mouse; D000071256:Uncoupling Protein 1; D000071246:Uncoupling Protein 2; D000071247:Uncoupling Protein 3; C495199:apelin-13 peptide