TY - JOUR
T1 - Divergent regulation of adipose tissue metabolism by calorie restriction and inhibition of growth hormone signaling
AU - Park, Seongjoon
AU - Komatsu, Toshimitsu
AU - Hayashi, Hiroko
AU - Trindade, Lucas Siqueira
AU - Yamaza, Haruyoshi
AU - Chiba, Takuya
AU - Shimokawa, Isao
N1 - Funding Information:
We are grateful to the staff at the Center for Frontier Life Sciences, Nagasaki University, for their technical assistance and animal care. We also thank Yutaka Araki and Yuko Moriyama for excellent technical assistance. This work was supported by Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (Nos. 15390128, 16790226 and 20790260).
PY - 2009/10
Y1 - 2009/10
N2 - Calorie restriction (CR) and a reduced growth hormone (GH) signal affect insulin sensitivity and lifespan in mammals in a similar manner. We investigated the effects of CR and moderate inhibition of GH on glucose-stimulated activation of insulin signaling and the expression of genes related to fat metabolism in white adipose tissue (WAT) in rats. We used 10-month-old male, wild-type (W) Wistar rats, fed ad libitum (AL) or a 30% CR diet from 6 weeks of age, and transgenic (Tg) rats with moderately suppressed GH signaling. Rats were killed 15 min after an intraperitoneal injection of glucose or saline. In control W-AL rats, the levels of serum insulin, phosphorylated (p) insulin receptor (pY-IR), p-Akt, and the expression of glucose transporter (Glut) 4 in the membrane fraction were greater in the glucose-injected group than in the saline-injected group, indicating significant activation of insulin signaling in response to glucose loading. In the W-CR and Tg-AL rats, the serum insulin and pY-IR levels were lower than those in the W-AL rats. The Akt-Glut pathway was up-regulated even after saline-injection. Expression levels of adipogenic and lipogenic genes including PPARγ, adiponectin, and its receptors, were higher in the W-CR rats than in the W-AL and Tg-AL rats. The present findings indicate adipose tissue metabolic profiles specific to CR.
AB - Calorie restriction (CR) and a reduced growth hormone (GH) signal affect insulin sensitivity and lifespan in mammals in a similar manner. We investigated the effects of CR and moderate inhibition of GH on glucose-stimulated activation of insulin signaling and the expression of genes related to fat metabolism in white adipose tissue (WAT) in rats. We used 10-month-old male, wild-type (W) Wistar rats, fed ad libitum (AL) or a 30% CR diet from 6 weeks of age, and transgenic (Tg) rats with moderately suppressed GH signaling. Rats were killed 15 min after an intraperitoneal injection of glucose or saline. In control W-AL rats, the levels of serum insulin, phosphorylated (p) insulin receptor (pY-IR), p-Akt, and the expression of glucose transporter (Glut) 4 in the membrane fraction were greater in the glucose-injected group than in the saline-injected group, indicating significant activation of insulin signaling in response to glucose loading. In the W-CR and Tg-AL rats, the serum insulin and pY-IR levels were lower than those in the W-AL rats. The Akt-Glut pathway was up-regulated even after saline-injection. Expression levels of adipogenic and lipogenic genes including PPARγ, adiponectin, and its receptors, were higher in the W-CR rats than in the W-AL and Tg-AL rats. The present findings indicate adipose tissue metabolic profiles specific to CR.
KW - Adipose tissue
KW - Calorie restriction
KW - Glucose uptake
KW - Growth hormone
KW - Insulin signal
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U2 - 10.1016/j.exger.2009.07.002
DO - 10.1016/j.exger.2009.07.002
M3 - Article
C2 - 19646410
AN - SCOPUS:70349211595
SN - 0531-5565
VL - 44
SP - 646
EP - 652
JO - Experimental Gerontology
JF - Experimental Gerontology
IS - 10
ER -