INSULIN-LIKE GROWTH-FACTOR BINDING-PROTEINS IN MATERNAL SERUM THROUGHOUT GESTATION AND IN THE PUERPERIUM - EFFECTS OF A PREGNANCY-ASSOCIATED SERUM PROTEASE ACTIVITY
INSULIN-LIKE GROWTH-FACTOR BINDING-PROTEINS IN MATERNAL SERUM THROUGHOUT GESTATION AND IN THE PUERPERIUM - EFFECTS OF A PREGNANCY-ASSOCIATED SERUM PROTEASE ACTIVITY
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DOI：
10.1210/jcem-71-4-806
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发表时间：
1990-10-01
影响因子：
5.8
通讯作者：
ROSENFELD, RG
中科院分区：
文献类型：
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作者：
GIUDICE, LC;FARRELL, EM;ROSENFELD, RG
已克隆并测序了编码三种主要胰岛素样生长因子结合蛋白（IGFBPs）的cDNA。我们用Western配体印迹法检测了正常月经周期、妊娠期和产后妇女血清中这些结合蛋白的分布。有没有变化，在任何结合蛋白的血清中的配置文件在妊娠早期相比，在月经周期的分泌期。然而，主要血清IGFBP-3的循环水平在妊娠6周后显著降低，持续进行性至足月，并在产后5天恢复至非妊娠水平。IGFBP-2在整个妊娠期间稳定下降。相反，IGFBP-1水平在第二个三个月上升。内切糖基化酶-F消化没有增强IGFBP-3的配体印迹检测。免疫沉淀与两个单独的抗体对IGFBP-3和IGFBP-2，然后通过蛋白质配体印迹法，证实了显着降低IGFBP-3水平后6周的妊娠和IGFBP-2更逐渐减少。与此相反，IGFBP-1单克隆抗体的免疫沉淀证实了IGFBP-1在妊娠期间的增加。内源性血清IGFs从血清IGFBPs分离酸色谱法，和80%的总IGF-结合活性的降低，在IGFBP部分的色谱妊娠与非妊娠血清中检测到活性炭吸附试验。此外，免疫沉淀IGF亲和交联IGFBP-3特异性抗血清的IGFBP馏分证实了显着减少IGFBP-3在妊娠期相比，非妊娠血清，并透露，只有在妊娠血清中，伴随出现的一个带与分子量为34 K和三个较低的强度带与分子量之间的十二烷基硫酸钠凝胶20- 26 K。将非妊娠血清与6周妊娠血清在37 ℃下孵育5小时，然后进行蛋白质配体印迹，结果显示，与对照组相比，混合物中IGFBP-3的含量仅略有减少。然而，足月妊娠与非妊娠血清在37 ℃下孵育5小时显示混合物中IGFBP-3显著减少。当碘标记的重组IGFBP-3与足月妊娠血清在相同条件下孵育时，通过凝胶电泳和放射自显影鉴定了29 K蛋白的出现，沿着三条分子量在17- 22 K之间的较弱条带。总之，数据表明，在非妊娠状态下，主要的循环血清IGFBP-3，在妊娠期间显着减少，其减少可能是由于内源性妊娠相关的血清蛋白酶。另一种主要的血清IGFBP，IGFBP-2，也在怀孕期间降低，其降低显然也可能与怀孕相关的pretease有关。另一方面，IGFBP-1在整个妊娠期间增加。
The cDNAs encoding three major insulin-like growth factor-binding proteins (IGFBPs) have been cloned and sequenced. We have examined, by Western ligand blotting, the profiles of these binding proteins in human frmale serum in the normal menstrual cycle, throughout pregnancy, and during postpartum period. There was no change in the serum profile of any of the binding proteins in early pregnancy compared to that in the secretory phase of the menstrual cycle. However, there was marked decrease in circulating levels of the main serum IGFBP, IGFBP-3, after 6 weeks of gestation, continuing progressively to term and returning to nonpregnant levels by 5 days postpartum. IGFBP-2 decreased steadily throughout gestation. In contrast, IGFBP-1 levels were found to rise by the second trimester. Endoglycosidase-F digestion did not enhance detection of IGFBP-3 by ligand blotting. Immunoprecipitations with two separate antibodies against IGFBP-3 and IGFBP-2, followed by Western ligand blotting, confirmed the marked decrease in IGFBP-3 levels after 6 weeks of gestation and the more gradual decrease in IGFBP-2. In contrast, immunoprecipitations with IGFBP-1 monoclonal antibodies confirmed the increase in IGFBP-1 during gestation. Endogenous serum IGFs were separated from serum IGFBPs by acid chromatography, and an 80% decrease in total IGF-binding activity in the IGFBP fraction of chromatographed pregnancy vs. nonpregnancy serum was detected by charcoal absorption assay. Furthermore, immunoprecipitations of IGF affinity cross-linked IGFBP fractions with IGFBP-3-specific antiserum confirmed a marked diminution of IGFBP-3 in pregnancy compared to nonpregnancy serum, and revealed, only in pregnancy serum, the concomitant appearance of a band with a mol wt of 34K and three less intense bands with mol wt between 20-26K on sodium dodecyl sulfate gels. Incubation of nonpregnancy serum with 6-week pregnancy serum at 37 C for 5 h, followed by Western ligand blotting, showed only a slight reduction in the amount of IGFBP-3 in the mixture compared to that in controls. However, incubation of term pregnancy with nonpregnancy serum at 37 C for 5 h revealed a marked reduction of IGFBP-3 in the mixture. When iodinated recombinant IGFBP-3 was incubated with term pregnancy serum under the same conditions, the appearance of a 29K protein was identified by gel electrophoresis and autoradiography, along with three less intense bands with mol wt between 17-22K. Taken together, the data demonstrate that the main circulating serum IGFBP in the nonpregnant state, IGFBP-3, is markedly reduced during pregnancy, and its reduction may be due to an endogenous pregnancy-related serum protease. Another major serum IGFBP, IGFBP-2, also decreases during pregnancy, and its reduction apparently may also be related to a pregancy-related pretease. IGFBP-1, on the other hand, increases throughout gestation.