CD40-induced signaling in human endothelial cells results in mTORC2- and Akt-dependent expression of vascular endothelial growth factor in vitro and in vivo.
CD40-induced signaling in human endothelial cells results in mTORC2- and Akt-dependent expression of vascular endothelial growth factor in vitro and in vivo.
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DOI：
10.4049/jimmunol.181.11.8088
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发表时间：
2008-12-01
期刊：
影响因子：
--
通讯作者：
Briscoe DM
中科院分区：
文献类型：
--
作者：
Dormond O;Contreras AG;Meijer E;Datta D;Flynn E;Pal S;Briscoe DM
我们检查了内皮细胞 (EC) 中介导血管内皮生长因子 (VEGF) 表达和 VEGF 诱导的血管生成的 CD40 依赖性信号。我们用可溶性 CD40L (sCD40L) 处理 EC 汇合培养物，通过蛋白质印迹发现，与未处理的细胞相比，Akt、4EBP-1 和 S6K1 的磷酸化显着增加。 EC 用全长 VEGF 启动子-荧光素酶构建体转染，并在不存在或存在雷帕霉素和 sCD40L 的情况下培养。我们发现雷帕霉素可阻断 mTORC1 和 mTORC2 信号传导，从而抑制 sCD40L 介导的 VEGF 反式激活。此外，通过Western blot，我们发现用小干扰RNA（siRNA）将EC转染至rictor（抑制mTORC2），而不是raptor（抑制mTORC1），抑制了VEGF的sCD40L依赖性蛋白表达。此外，我们发现转染 raptor siRNA 的 EC 中磷酸化 Akt 和 VEGF 的基础水平有所增加。此外，雷帕霉素未能抑制 VEGF 启动子激活，以及用 Akt 组成型活性构建体转染的 EC 中的 VEGF 蛋白表达，进一步证明 mTORC1 对于 CD40 和 Akt 诱导的 VEGF 表达不是必需的。最后，我们将人类 CD40L 转染的成纤维细胞或模拟转染子注射到 SCID 小鼠的人类皮肤中。我们发现注射 CD40L 转染子（而非模拟细胞）会导致 VEGF 表达并介导显着的血管生成反应，并且在用雷帕霉素治疗的小鼠中这种反应减弱。总之，这些观察结果表明 mTORC2 和 Akt 促进 EC 中 CD40 诱导的 VEGF 表达，这对于肿瘤生长和慢性炎症性疾病的进展具有临床重要性。
We have examined CD40-dependent signals in endothelial cells (EC) mediating the expression of vascular endothelial growth factor (VEGF) and VEGF-induced angiogenesis. We treated confluent cultures of EC with soluble CD40L (sCD40L), and by Western blot found a marked increase in the phosphorylation of Akt, 4EBP-1, and S6K1, compared with untreated cells. EC were transfected with a full-length VEGF promoter-luciferase construct and cultured in the absence or presence of rapamycin and sCD40L. We found that rapamycin, which blocks mTORC1 and mTORC2 signaling, inhibited sCD40L-mediated transactivation of VEGF. In addition, by Western blot, we found that the transfection of EC with small interfering RNA (siRNA) to rictor (to inhibit mTORC2), and not raptor (to inhibit mTORC1), inhibited sCD40L-dependent protein expression of VEGF. In addition, we found that basal levels of phosphorylated Akt as well as VEGF were increased in EC transfected with the raptor siRNA. Also, rapamycin failed to inhibit VEGF promoter activation, as well as VEGF protein expression in EC transfected with a constitutively active construct of Akt, further demonstrating that mTORC1 is not necessary for CD40- and Akt-induced expression of VEGF. Finally, we injected human CD40L-transfected fibroblasts or mock transfectants into human skin on SCID mice. We found that the injection of CD40L transfectants, but not mock cells, resulted in VEGF expression and mediated a marked angiogenesis reaction, and this response was reduced in mice treated with rapamycin. Together, these observations indicate that mTORC2 and Akt facilitate CD40-inducible expression of VEGF in EC, which is of clinical importance in tumor growth and the progression of chronic inflammatory diseases.
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影响因子：
6.2
作者：
Moulton, KS;Melder, RJ;Briscoe, DM
通讯作者：
Briscoe, DM
影响因子：
5
作者：
Miotla, J;Maciewicz, R;Paleolog, E
通讯作者：
Paleolog, E
影响因子：
64.5
作者：
ARUFFO, A;FARRINGTON, M;OCHS, HD
通讯作者：
OCHS, HD
DOI：
10.1084/jem.183.5.2129
发表时间：
1996-05-01
期刊：
The Journal of experimental medicine
影响因子：
--
作者：
Borrow P;Tishon A;Lee S;Xu J;Grewal IS;Oldstone MB;Flavell RA
通讯作者：
Flavell RA
影响因子：
10.5
作者：
Fingar, DC;Salama, S;Blenis, J
通讯作者：
Blenis, J