Characterization of the receptor for insulin-like growth factor II in bone cells.
Characterization of the receptor for insulin-like growth factor II in bone cells.
复制标题
骨细胞中胰岛素样生长因子 II 受体的表征。
DOI：
10.1002/jcp.1041400120
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发表时间：
1989
影响因子：
5.6
通讯作者：
Baylink,D
中科院分区：
文献类型：
--
作者：
Mohan,S;Linkhart,T;Rosenfeld,R;Baylink,D
我们之前已经证明胰岛素样生长因子II （IGF - II）是由骨细胞产生的，并且IGF - II刺激骨细胞的细胞增殖和胶原合成。现在，我们通过证明IGF - II与新生小鼠颅骨和胚胎鸡颅骨的骨细胞特异性结合，扩展了这些体外研究结果。[125] IGF - II在鸡胚胎颅骨细胞中的结合动力学表现出时间和温度依赖性。通过Scatchard分析[125]，IGF‐II与鸡颅骨细胞结合的表观Kdof为1.4 × 1010M，计算出的受体位点浓度为40,000个/细胞。特异性特征表明，IGF - II在取代IGF - II示踪剂方面明显比IGF - I或胰岛素更有效。未标记的IGF - II与[125]I IGF - II结合的竞争显示出0.5至25 ng/ml之间的剂量依赖性位移。在1‐2 ng/ml的浓度下，IGF‐II与鸡和小鼠颅骨细胞的结合量达到50% [125]；在125 ng/ml未标记的IGF - II存在下，90%的特异性结合[125]IGF - II被取代。IGF - I与鸡和小鼠骨细胞的交叉反应性低于5%[125]。II型受体抑制抗体R‐II‐PAB1以剂量依赖性的方式抑制[125]I - IGF‐II与小鼠骨细胞和H‐35大鼠肝癌细胞（含有II型受体但不含I型受体）的结合。R‐II‐PAB1还能抑制小鼠骨细胞的基底细胞增殖以及IGF‐II‐、IGF‐I‐和成纤维细胞生长因子（FGF）‐诱导的细胞增殖。在鸡颅骨骨细胞和TE89人骨肉瘤细胞中，R‐II‐PAB1既不抑制IGF‐II的结合[125]，也不抑制IGF‐II诱导的细胞增殖。这些结果以及我们的发现，在最大剂量的IGF - I存在下，IGF - II增加了鸡骨细胞的增殖，这表明IGF - II至少部分的有丝分裂作用是通过骨细胞中的II型受体介导的，而不是I型受体。
We have previously shown that insulin‐like growth factor II (IGF‐II) is produced by bone cells and that IGF‐II stimulates cell proliferation and collagen synthesis in bone cells. We now extend these in vitro findings by demonstrating specific IGF‐II binding to bone cells derived from newborn mouse calvaria and embryonic chick calvaria. The kinetics of [125]I IGF‐II binding in embryonic chick calvaria cells showed time and temperature dependence. Scatchard analysis of [125]I IGF‐II binding to chick calvaria cells showed an apparent Kdof 1.4 × 1010M, with a calculated receptor site concentration of 40,000/cell. The specificity characteristics showed that IGF‐II was significantly more potent than IGF‐I or insulin in displacing IGF‐II tracer. Competition for binding of [125]I IGF‐II by unlabeled IGF‐II showed a dose‐dependent displacement between 0.5 and 25 ng/ml. Fifty percent displacement of [125]I IGF‐II binding to chick and mouse calvarial cells was achieved at 1‐2 ng/ml; 90% of specific binding of [125]I IGF‐II was displaceable in the presence of 125 ng/ml of unlabeled IGF‐II. IGF‐I showed less than 5% cross reactivity for displacement of [125]I IGF‐II binding to chick and mouse bone cells. Type II receptor inhibitory antibodies, R‐II‐PAB1 inhibited the binding of [125]I IGF‐II to mouse bone cells and H‐35 rat hepatoma cells (which contain type II but not type I receptors) in a dose‐dependent manner. R‐II‐PAB1 also inhibited basal cell proliferation as well as IGF‐II‐, IGF‐I‐, and fibroblast growth factor (FGF)‐induced cell proliferation in mouse bone cells. In chick calvaria bone cells and TE89 human osteosarcoma cells, R‐II‐PAB1 inhibited neither binding of [125]I IGF‐II nor IGF‐ll‐induced cell proliferation. These results together with our findings that IGF‐II increased chick bone cell proliferation in the presence of maximal doses of IGF‐I suggest that at least part of the mitogenic action of IGF‐II is mediated through type II rather than type I receptors in bone cells.