Testosterone stimulates glucose uptake and GLUT4 translocation through LKB1/AMPK signaling in 3T3-L1 adipocytes
Testosterone stimulates glucose uptake and GLUT4 translocation through LKB1/AMPK signaling in 3T3-L1 adipocytes
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DOI：
10.1007/s12020-015-0666-y
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发表时间：
2016-01-01
期刊：
影响因子：
3.7
通讯作者：
Fukui, Michiaki
中科院分区：
文献类型：
--
作者：
Mitsuhashi, Kazuteru;Senmaru, Takafumi;Fukui, Michiaki
老年男性血清睾酮浓度下降与代谢紊乱有关。据报道，替吉奥可增加骨骼肌细胞和心肌细胞中GLUT 4依赖性葡萄糖摄取。然而，目前还没有关于脂肪细胞对睾酮刺激的葡萄糖摄取的研究。本研究旨在确定睾酮对脂肪细胞葡萄糖摄取的影响。在3 T3-L1脂肪细胞中用2-[H-3]脱氧葡萄糖评估葡萄糖摄取。分别通过免疫荧光和免疫印迹法在质膜（PM）片和PM组分中评价GLUT 4易位。通过免疫印迹法检测GLUT 4易位相关蛋白激酶（包括Akt、AMPK、LKB 1、CaMKI、CaMKII和Cbl）的活化。雄激素受体（AR）mRNA的表达水平和AR易位到PM分别通过实时RTPCR和免疫印迹法进行评估。结果表明，高剂量（100 nM）睾酮和睾酮-BSA增加葡萄糖摄取和GLUT 4转运到PM，独立于细胞内AR。睾酮和睾酮-BSA刺激AMPK、LKB 1和CaMK II的磷酸化。通过siRNA敲低LKB 1减弱了睾酮和睾酮-BSA刺激的AMPK磷酸化和葡萄糖摄取。这些结果表明，高剂量睾酮和睾酮-BSA通过诱导LKB 1/AMPK信号通路增加3 T3-L1脂肪细胞中GLUT 4依赖性葡萄糖摄取。
Decreases in serum testosterone concentrations in aging men are associated with metabolic disorders. Testosterone has been reported to increase GLUT4-dependent glucose uptake in skeletal muscle cells and cardiomyocytes. However, studies on glucose uptake occurring in response to testosterone stimulation in adipocytes are currently not available. This study was designed to determine the effects of testosterone on glucose uptake in adipocytes. Glucose uptake was assessed with 2-[H-3] deoxyglucose in 3T3-L1 adipocytes. GLUT4 translocation was evaluated in plasma membrane (PM) sheets and PM fractions by immunofluorescence and immunoblotting, respectively. Activation of GLUT4 translocation-related protein kinases, including Akt, AMPK, LKB1, CaMKI, CaMKII, and Cbl was followed by immunoblotting. Expression levels of androgen receptor (AR) mRNA and AR translocation to the PM were assessed by real-time RTPCR and immunoblotting, respectively. The results showed that both high-dose (100 nM) testosterone and testosterone-BSA increased glucose uptake and GLUT4 translocation to the PM, independently of the intracellular AR. Testosterone and testosterone-BSA stimulated the phosphorylation of AMPK, LKB1, and CaMKII. The knockdown of LKB1 by siRNA attenuated testosterone-and testosterone-BSA-stimulated AMPK phosphorylation and glucose uptake. These results indicate that high-dose testosterone and testosterone-BSA increase GLUT4-dependent glucose uptake in 3T3-L1 adipocytes by inducing the LKB1/AMPK signaling pathway.