Anti-apoptotic signaling of pleiotrophin through its receptor, anaplastic lymphoma kinase
Anti-apoptotic signaling of pleiotrophin through its receptor, anaplastic lymphoma kinase
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DOI：
10.1074/jbc.m203963200
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发表时间：
2002-09-27
影响因子：
4.8
通讯作者：
Wellstein, A
中科院分区：
文献类型：
--
作者：
Bowden, ET;Stoica, GE;Wellstein, A
分泌的生长因子多效生长因子（PTN）可诱导表达该生长因子受体（间变性淋巴瘤激酶（ALK））的细胞中的有丝分裂。在这里，我们研究PTN产生抗凋亡信号的能力。我们证明PTN是SW-13上皮细胞的存活因子，并表明核酶介导的SW-13细胞中ALK的消耗消除了PTN的这种作用。此外，在血清饥饿的NIH 3 T3成纤维细胞中，PTN以0.2 ng/ml的EC 50防止细胞凋亡（通过膜联蛋白V染色测量），并在较高浓度的PTN下诱导细胞生长。针对ALK受体的PTN配体结合结构域（α-LBD）的多克隆抗体是NIH 3 T3细胞中ALK的部分激动剂。该a-LBD抗体显示出抗细胞凋亡的高激动剂活性（相对于PTN为56 +/-9%），细胞生长的低激动剂活性（相对于PTN为21 +/-1%），并且是PTN诱导的细胞生长的拮抗剂（61 +/-2%抑制）。PTN可激活NIH 3 T3细胞中的MAP激酶和PI 3-激酶级联反应，这种作用可持续3 h。令人惊讶的是，PTN的抗凋亡作用被MAP激酶抑制剂U 0126完全阻断，但不受PI 3-激酶抑制剂LY 294002的影响。相反，PTN依赖的细胞生长需要MAPK和PI 3-激酶活性。我们得出结论，在NIH 3 T3成纤维细胞中，PTN通过ALK的抗凋亡信号传导是通过MAP激酶途径。
The secreted growth factor pleiotrophin (PTN) can induce mitogenesis in cells that express the receptor for this growth factor, anaplastic lymphoma kinase (ALK). Here we examine the ability of PTN to produce antiapoptotic signals. We demonstrate that PTN is a survival factor for SW-13 epithelial cells and show that ribozymemediated depletion of ALK from SW-13 cells abolishes this effect of PTN. Furthermore, in serum-starved NIH3T3 fibroblasts PTN prevents apoptosis (measured by annexin V staining) with an EC50 of 0.2 ng/ml and induces cell growth at higher concentrations of PTN. A polyclonal antibody against the PTN ligand-binding domain of the ALK receptor (alpha-LBD) was a partial agonist for ALK in NIH3T3 cells. This a-LBD antibody showed high agonist activity for anti-apoptosis (56 +/- 9% relative to PTN), low agonist activity for cell growth (21 +/- 1% relative to PTN), and was an antagonist of PTN-induced cell growth (61 +/- 2% inhibition). Both MAP kinase and phosphatidylinositol (PI) 3-kinase cascades in NIH3T3 cells were activated by PTN, and this effect persisted for up to 3 h. Surprisingly, the anti-apoptotic effect of PTN was completely blocked by the MAP kinase inhibitor U0126, but was not affected by the PI 3-kinase inhibitor LY294002. In contrast, PTN-dependent cell growth required both MAPK and PI3-kinase activity. We conclude that anti-apoptotic signaling of PTN through ALK in NIH3T3 fibroblasts is via the MAP kinase pathway.