Kubota Yoshitaka, Unoki Hiroyuki, Bujo Hideaki, Rikihisa Naoaki, Udagawa Akikazu, Yoshimoto Shinya, Ichinose Masaharu, Saito Yasushi
Department of Plastic and Reconstructive Surgery, Chiba University Graduate School of Medicine, Chiba 260-8670, Japan.
Biochem Biophys Res Commun. 2008 Mar 28;368(1):81-7. doi: 10.1016/j.bbrc.2008.01.035. Epub 2008 Jan 15.
The increased population of TLR2/TNF-alpha co-expressing adipocytes is associated with the development of insulin resistance. We have herein shown the significance of low-dose growth hormone (GH) supplementation for the regulation of TLR2 and TNF-alpha expressions in visceral fat using different kinds of mouse models fed with a high-fat diet. Low-dose GH supplementation reduced the increased population of TLR2/TNF-alpha co-expressing adipocytes in high-fat fed mice. The neutralization of IGF-1 abolished the effect of GH supplementation on the TLR2 expression using GH-overexpressing mice. IGF-1, but not GH, inhibited the FFA-induced TLR2 and TNF-alpha expression in 3T3-L1 cells. Finally, low-dose GH supplementation reduced the TLR2 expression without an obvious change in the visceral fat volume in ob/ob mice. These results indicate that low-dose GH supplementation possibly inhibits the high-fat induced change of the adipocytes to TLR2/TNF-alpha co-expressing cells through the action of IGF-1.
TLR2/TNF-α共表达脂肪细胞数量增加与胰岛素抵抗的发展有关。我们在此利用不同种类的高脂饮食喂养小鼠模型，展示了低剂量生长激素（GH）补充对内脏脂肪中TLR2和TNF-α表达调节的重要性。低剂量GH补充减少了高脂喂养小鼠中TLR2/TNF-α共表达脂肪细胞数量的增加。使用GH过表达小鼠，IGF-1的中和消除了GH补充对TLR2表达的影响。IGF-1而非GH抑制了3T3-L1细胞中游离脂肪酸（FFA）诱导的TLR2和TNF-α表达。最后，低剂量GH补充降低了ob/ob小鼠的TLR2表达，而内脏脂肪体积无明显变化。这些结果表明，低剂量GH补充可能通过IGF-1的作用抑制高脂诱导的脂肪细胞向TLR2/TNF-α共表达细胞的转变。
