分类： 生物学 >> 生物医药 提交时间： 2017-05-10
摘要： The role of AMP-activated protein kinase (AMPK) in adipocyte differentiation is not completely understood. Here we reported that an AMPK inhibitor, compound C, significantly inhibited adipogenic differentiation of 3T3-L1 cells in a dose dependent manner, and this inhibitory effect was primarily effective in the initial stage of differentiation. Compound C prevented the mitotic clonal expansion (NICE) of preadipocytes, probably by hibiting expression of CCAAT/enhancer-binding protein (C/EBP)beta and delta, and subsequently blocked the expression of C/EBP alpha and peroxisome proliferator-activated receptor (PPAR)gamma and transcriptional activation of genes that produce the adipocyte phenotype. AMPK activity was also suppressed by compound C treatment during the early phase of adipogenic differentiation, which indicated that suppressed activation of AMPK by compound C may inhibit the MCE process of preadipocytes. Our results suggest that compound C might serve as a useful molecule in both basic and clinical research on adipogenesis and as a potential lead compound for the treatment of, obesity.
分类： 生物学 >> 生态学 提交时间： 2017-11-17
Mao, LF?(Mao, Liufeng)
Lin, WH?(Lin, Wanhua)
Nie, T?(Nie, Tao)
Hui, XY?(Hui, Xiaoyan)
Gao, XF?(Gao, Xuefei)
Li, K?(Li, Kuai)
Ding, MX?(Ding, Mengxiao)
Tang, XF?(Tang, Xiaofeng)
Li, P?(Li, Peng)
Wang, Y?(Wang, Yu)
Xu, AM?(Xu, Aimin)
Liu, PT?(Liu, Pentao)
Wu, DH?(Wu, Donghai)
摘要： Background: The adapter proteins Appl1 (adaptor protein containing pleckstrin homology domain, phosphotyrosine domain, and leucine zipper motif 1) and Appl2 are highly homologous and involved in several signaling pathways. While previous studies have shown that Appl1 plays a pivotal role in adiponectin signaling and insulin secretion, the physiological functions of Appl2 are largely unknown. Results: In the present study, the role of Appl2 in sepsis shock was investigated by using Appl2 knockout (KO) mice. When challenged with lipopolysaccharides (LPS), Appl2 KO mice exhibited more severe symptoms of endotoxin shock, accompanied by increased production of proinflammatory cytokines. In comparison with the wild-type control, deletion of Appl2 led to higher levels of TNF-alpha and IL-1 beta in primary macrophages. In addition, phosphorylation of Akt and its downstream effector NF-kappa B was significantly enhanced. By co-immunoprecipitation, we found that Appl2 and Appl1 interacted with each other and formed a complex with PI3K regulatory subunit p85 alpha, which is an upstream regulator of Akt. Consistent with these results, deletion of Appl1 in macrophages exhibited characteristics of reduced Akt activation and decreased the production of TNF alpha and IL-1 beta when challenged by LPS. Conclusions: Results of the present study demonstrated that Appl2 is a critical negative regulator of innate immune response via inhibition of PI3K/Akt/NF-kappa B signaling pathway by forming a complex with Appl1 and PI3K.Conclusions: Results of the present study demonstrated that Appl2 is a critical negative regulator of innate immune response via inhibition of PI3K/Akt/NF-kappa B signaling pathway by forming a complex with Appl1 and PI3K.
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