分类: 生物学 >> 生态学 提交时间: 2017-11-17
摘要: Both mammals and adult humans possess classic brown adipocytes and beige adipocytes, and the amount and activity of these adipocytes are considered key factors in combating obesity and its associated metabolic diseases. Uncoupling protein 1 (Ucp1) is the functional marker of both brown and beige adipocytes. To facilitate a reliable, easy, and sensitive measurement of Ucp1 expression both in vivo and in vitro, we generated a Ucp1-2A-luciferase knock-in mouse by deleting the stop codon for the mouse Ucp1 gene and replacing it with a 2A peptide. This peptide was followed by the luciferase coding sequence to recapitulate the expression of the Ucp1 gene at the transcriptional and translational levels. With this mouse, we discovered a cold-sensitive brown/beige adipose depot underneath the skin of the ears, which we named uBAT. Because of the sensitivity and high dynamic range of luciferase activity, the Ucp1-2A-luciferase mouse is useful for both in vitro quantitative determination and in vivo visualization of nonshivering thermogenesis. With the use of this model, we identified and characterized axitinib, an oral small-molecule tyrosine kinase inhibitor, as an effective browning agent.
分类: 生物学 >> 生态学 提交时间: 2017-11-17
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.
分类: 生物学 >> 生态学 提交时间: 2017-11-17
摘要: In recent years, immunotherapies, such as those involving chimeric antigen receptor (CAR) T cells, have become increasingly promising approaches to non-small-cell lung cancer (NSCLC) treatment. In this study, we explored the antitumor potential of prostate stem cell antigen (PSCA)-redirected CAR T and mucin 1 (MUC1)-redirected CAR T cells in tumor models of NSCLC. First, we generated patient-derived xenograft (PDX) mouse models of human NSCLC that maintained the antigenic profiles of primary tumors. Next, we demonstrated the expression of PSCA and MUC1 in NSCLC, followed by the generation and confirmation of the specificity and efficacy of PSCA-and MUC1-targeting CAR T cells against NSCLC cell lines in vitro. Finally, we demonstrated that PSCA-targeting CAR T cellscould efficiently suppress NSCLC tumor growth in PDX mice and synergistically eliminate PSCA(+)MUC1(+) tumors when combined with MUC1-targeting CAR Tcells. Taken together, our studies demonstrate that PSCA and MUC1 are both promising CAR T cell targets in NSCLC and that the combinatorial targeting ofthese antigens could further enhance the antitumor efficacy of CAR T cells.