目的:研究肥胖小鼠及正常小鼠不同周龄下丘脑组织SH2B1(adapter protein with a Src-homology 2 domain),细胞因子信号转导抑制蛋白3(the suppressor of cytokine signaling-3,SOCS3),蛋白质酪氨酸磷酸酶1B(proteintyrosine phosphatase...目的:研究肥胖小鼠及正常小鼠不同周龄下丘脑组织SH2B1(adapter protein with a Src-homology 2 domain),细胞因子信号转导抑制蛋白3(the suppressor of cytokine signaling-3,SOCS3),蛋白质酪氨酸磷酸酶1B(proteintyrosine phosphatase 1B,PTP1B)和神经肽Y(neturopetide Y,NPY)表达的变化规律及其与血清瘦素及胰岛素水平的关系。方法:选用健康C57BL/6乳鼠制作肥胖动物模型,计算Lee’s指数及稳态模型胰岛素抵抗指数。荧光定量RT-PCR法检测下丘脑SH2B1,SOCS3及PTP1B mRNA表达量,Western印迹检测下丘脑SH2B1和NPY蛋白表达量。结果:与同周龄对照组小鼠相比,肥胖组小鼠下丘脑组织SH2B1 mRNA表达减少,SOCS3及PTP1B mRNA表达增加;Western印迹结果显示:肥胖组小鼠SH2B1蛋白表达水平较对照组下降,NPY表达升高。直线相关分析显示:血清瘦素和血清空腹胰岛素水平与SH2B1 mRNA表达呈负相关,与SOCS3及PTP1B mRNA表达正相关。结论:SH2B1,SOCS3,PTP1B及NPY是肥胖发生、发展过程中的关键因子。展开更多
包含Src同源2结构域的蛋白酪氨酸磷酸酶2(Src homology region 2-containing protein tyrosine phosphatase 2,SHP2)是目前唯一被证实具有促癌作用的细胞质蛋白酪氨酸磷酸酶,在多种恶性肿瘤中高表达。SHP2可以通过介导受体酪氨酸激酶(Re...包含Src同源2结构域的蛋白酪氨酸磷酸酶2(Src homology region 2-containing protein tyrosine phosphatase 2,SHP2)是目前唯一被证实具有促癌作用的细胞质蛋白酪氨酸磷酸酶,在多种恶性肿瘤中高表达。SHP2可以通过介导受体酪氨酸激酶(Receptor tyrosine kinase, RTK)下游的RAS/ERK、PI3K/Akt和JAK/STAT等信号通路促进肿瘤发生发展,影响肿瘤预后。同时,SHP2参与调控PD-1/PD-L1、CTLA-4、BLTA和TIGIT等免疫检查点信号通路,对于肿瘤微环境中各种免疫细胞都有重要的调节作用。靶向SHP2不仅可以通过抑制RTK下游信号通路,还可以通过改善免疫微环境治疗恶性肿瘤。因此,SHP2具有免疫与靶向双重治疗肿瘤的功能,作为抗肿瘤治疗的靶点展现出极高的潜能与价值。展开更多
To complete their life cycle and spread, viruses interfere with and gain control of diverse cellular processes, this most often occurring through interaction between viral proteins(VPs) and resident protein partners. ...To complete their life cycle and spread, viruses interfere with and gain control of diverse cellular processes, this most often occurring through interaction between viral proteins(VPs) and resident protein partners. Among the latter, Src family kinases(SFKs), a class of non-receptor tyrosine kinases that contributes to the conversion of extracellular signals into intracellular signaling cascades and is involved in virtually all cellular processes, have recently emerged as critical mediators between the cell's infrastructure and the viral demands. In this scenario, structural or ex novo synthesized VPs are able to bind to the different domains of these enzymes through specific short linear motifs present along their sequences. Proline-rich motifs displaying the conserved minimal consensus PxxP and recognizing the SFK Src homology(SH)3 domain constitute a cardinal signature for the formation of multiprotein complexes and this interaction may promote phosphorylation of VPs by SFKs, thus creating phosphotyrosine motifs that become a docking site for the SH2 domains of SFKs or other SH2 domain-bearing signaling molecules. Importantly, the formation of these assemblies also results in a change in the activity and/or location of SFKs, and these events are critical in perturbing key signalingpathways so that viruses can utilize the cell's machinery to their own benefit. In the light of these observations, although VPs as such, especially those with enzyme activity, are still regarded as valuable targets for therapeutic strategies, multiprotein complexes composed of viral and host cell proteins are increasingly becoming objects of investigation with a view to deeply characterize the structural aspects that favor their formation and to develop new compounds able to contrast viral diseases in an alternative manner.展开更多
文摘目的:研究肥胖小鼠及正常小鼠不同周龄下丘脑组织SH2B1(adapter protein with a Src-homology 2 domain),细胞因子信号转导抑制蛋白3(the suppressor of cytokine signaling-3,SOCS3),蛋白质酪氨酸磷酸酶1B(proteintyrosine phosphatase 1B,PTP1B)和神经肽Y(neturopetide Y,NPY)表达的变化规律及其与血清瘦素及胰岛素水平的关系。方法:选用健康C57BL/6乳鼠制作肥胖动物模型,计算Lee’s指数及稳态模型胰岛素抵抗指数。荧光定量RT-PCR法检测下丘脑SH2B1,SOCS3及PTP1B mRNA表达量,Western印迹检测下丘脑SH2B1和NPY蛋白表达量。结果:与同周龄对照组小鼠相比,肥胖组小鼠下丘脑组织SH2B1 mRNA表达减少,SOCS3及PTP1B mRNA表达增加;Western印迹结果显示:肥胖组小鼠SH2B1蛋白表达水平较对照组下降,NPY表达升高。直线相关分析显示:血清瘦素和血清空腹胰岛素水平与SH2B1 mRNA表达呈负相关,与SOCS3及PTP1B mRNA表达正相关。结论:SH2B1,SOCS3,PTP1B及NPY是肥胖发生、发展过程中的关键因子。
文摘To complete their life cycle and spread, viruses interfere with and gain control of diverse cellular processes, this most often occurring through interaction between viral proteins(VPs) and resident protein partners. Among the latter, Src family kinases(SFKs), a class of non-receptor tyrosine kinases that contributes to the conversion of extracellular signals into intracellular signaling cascades and is involved in virtually all cellular processes, have recently emerged as critical mediators between the cell's infrastructure and the viral demands. In this scenario, structural or ex novo synthesized VPs are able to bind to the different domains of these enzymes through specific short linear motifs present along their sequences. Proline-rich motifs displaying the conserved minimal consensus PxxP and recognizing the SFK Src homology(SH)3 domain constitute a cardinal signature for the formation of multiprotein complexes and this interaction may promote phosphorylation of VPs by SFKs, thus creating phosphotyrosine motifs that become a docking site for the SH2 domains of SFKs or other SH2 domain-bearing signaling molecules. Importantly, the formation of these assemblies also results in a change in the activity and/or location of SFKs, and these events are critical in perturbing key signalingpathways so that viruses can utilize the cell's machinery to their own benefit. In the light of these observations, although VPs as such, especially those with enzyme activity, are still regarded as valuable targets for therapeutic strategies, multiprotein complexes composed of viral and host cell proteins are increasingly becoming objects of investigation with a view to deeply characterize the structural aspects that favor their formation and to develop new compounds able to contrast viral diseases in an alternative manner.
