Adenovirus-mediated high expression of resistin causes dyslipidemia in mice.
The adipocyte-derived hormone resistin has been proposed as a possible link between obesity and insulin resistance in murine models. Many recent studies have reported physiological roles for resistin in glucose homeostasis, one of which is enhancement of glucose production from the liver by up-regulating gluconeogenic enzymes such as glucose-6-phosphatase and phosphoenolpyruvate carboxykinase. However, its in vivo roles in lipid metabolism still remain to be clarified. In this study, we investigated the effects of resistin overexpression on insulin action and lipid metabolism in C57BL/6 mice using an adenoviral gene transfer technique. Elevated plasma resistin levels in mice treated with the resistin adenovirus (AdmRes) were confirmed by Western blotting analysis and RIAs. Fasting plasma glucose levels did not differ between AdmRes-treated mice and controls, but the basal insulin concentration was significantly elevated in AdmRes-treated mice. In AdmRes-treated mice, the glucose-lowering effect of insulin was impaired, as evaluated by insulin tolerance tests. Furthermore, total cholesterol and triglyceride concentrations were significantly higher, whereas the high-density lipoprotein cholesterol level was significantly lower. Lipoprotein analysis revealed that low-density lipoprotein was markedly increased in AdmRes-treated mice, compared with controls. In addition, in vivo Triton WR-1339 studies showed evidence of enhanced very low-density lipoprotein production in AdmRes-treated mice. The expressions of genes involved in lipoprotein metabolism, such as low-density lipoprotein receptor and apolipoprotein AI in the liver, were decreased. These results suggest that resistin overexpression induces dyslipidemia in mice, which is commonly seen in the insulin-resistant state, partially through enhanced secretion of lipoproteins.
Sato
Naoichi
N
Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
Kobayashi
Kunihisa
K
Inoguchi
Toyoshi
T
Sonoda
Noriyuki
N
Imamura
Minako
M
Sekiguchi
Naotaka
N
Nakashima
Naoki
N
Nawata
Hajime
H
D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D002784:Cholesterol / Q000097:blood; D015870:Gene Expression; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D006729:Hormones, Ectopic / Q000097:blood / Q000235:genetics / Q000494:pharmacology; D006949:Hyperlipidemias / Q000097:blood / Q000139:chemically induced* / Q000503:physiopathology; D007333:Insulin Resistance; D008074:Lipoproteins / Q000378:metabolism; D008077:Lipoproteins, LDL / Q000097:blood; D008079:Lipoproteins, VLDL / Q000096:biosynthesis; D008099:Liver / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D018482:Muscle, Skeletal / Q000378:metabolism; D052243:Resistin; D013997:Time Factors
D006729:Hormones, Ectopic; D008074:Lipoproteins; D008077:Lipoproteins, LDL; D008079:Lipoproteins, VLDL; D052243:Resistin; C499623:Retn protein, mouse; D002784:Cholesterol