Construction of adiponectin-encoding plasmid DNA and overexpression in mice in vivo

The effects of elevated adiponectin (ADN) plasma levels on food intake, body weight, and lipid deposition of wild-type mice through ADN gene transfer using hydrodynamic based-gene delivery (HD) were investigated. The administration of pTarget/ADN significantly increased the blood ADN levels on days 1, 3, and 7 as well as food intake and body weight. Reverse transcription polymerase chain reaction (RT-PCR) was used to investigate the key-function genes involved in lipid deposition on epididymal fat, gastrocnemius, and extensor digitorum longus on days 1 and 7. The amounts of adipose triglyceride lipase, hormone-sensitive lipase, and lipoprotein lipase mRNA in the three samples significantly increased. We determined sirtuin 1 (SIRT1), forkhead box O3 (FOXO3a), and peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) gene expression and protein level in these samples. The amounts of SIRT1, FOXO3a, and PGC-1α mRNA in epididymal fat, gastrocnemius, and extensor digitorum longus remarkably increased. However, a significant increase in SIRT1 and PGC-1α protein levels was only observed in extensor digitorum longus. These results suggest that high doses of ADN can increase food intake and body weight. Elevated ADN levels may also affect fat deposition on the adipose tissue and skeletal muscles of wild-type mice via SIRT1, FOXO3a, and its downstream targets, including PGC-1α.