Presence of brain-derived neurotrophic factor in brain and human and rat but not mouse serum detected by a sensitive and specific immunoassay
Presence of brain-derived neurotrophic factor in brain and human and rat but not mouse serum detected by a sensitive and specific immunoassay
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DOI：
10.1016/0006-8993(95)01321-0
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发表时间：
1996-02-12
期刊：
影响因子：
2.9
通讯作者：
Altar, CA
中科院分区：
文献类型：
--
作者：
Radka, SF;Holst, PA;Altar, CA
脑源性神经营养因子（Brain-derived neurotrophic factor， BDNF）是在神经元发育和稳态中起关键作用的内源性蛋白之一。我们在这里描述了表征和使用一个敏感和特异性的酶联免疫测定（EIA） BDNF蛋白。重组BDNF在低至10 pg/ml的浓度下被检测到，而在高至100 ng/ml的浓度下，EIA未检测到NT-3、NT-4/5或NGF。由于BDNF蛋白序列在人类、小鼠和大鼠中是相同的，我们利用BDNF EIA来检测这些物种的循环或大脑区域中的BDNF。在人和大鼠血清中检测到高浓度的BDNF，而在柠檬酸盐的人和大鼠血浆中，BDNF水平降低了50倍。20%的人血浆中的BDNF信号（66-141 pg/ml）可以通过预先暴露于BDNF特异性单克隆抗体（Mab）完全阻断，但不能通过暴露于5倍浓度的相同同型的无关Mab （IgG1）。血浆BDNF水平与血清素呈显著正相关（r = +0.86），血清素是活化血小板特异性释放的一种吲哚胺。这些结果与人类和大鼠血浆中检测到的BDNF来源于血小板脱颗粒的观点一致，并且循环中的BDNF水平可以忽略不计。与人或大鼠血清相比，小鼠血清不含可检测到的BDNF。在小鼠和大鼠海马、额叶皮层和新纹状体中，BDNF蛋白含量为108 ~ 256 ng/g。因此，未能在小鼠血清中检测到BDNF不是由于检测缺陷，而是强调了BDNF组织特异性表达的显著物种差异，这可能具有生物学重要性。BDNF蛋白在血液和大脑区域的存在，其数量大大超过了NGF所描述的数量，证实了这种广泛作用的神经营养因子的丰富分布。
Brain-derived neurotrophic factor (BDNF) is one of several endogenous proteins that play key roles in neuronal development and homeostasis. We describe here the characterization and use of a sensitive and specific enzyme-linked immunoassay (EIA) for BDNF protein. Recombinant BDNF was detected at concentrations as low as 10 pg/ml, whereas the EIA did not detect NT-3, NT-4/5, or NGF at concentrations as high as 100 ng/ml. Because BDNF protein sequences are identical among humans, mice, and rats, we utilized the BDNF EIA to detect BDNF in the circulation or brain regions of these species. High concentrations of BDNF were detected in human and rat serum, and up to 50-fold lower BDNF levels were present in citrated human or rat plasma. The BDNF signal (66-141 pg/ml) in 20% human plasma was completely blocked by pre-exposure of plasma to a monoclonal antibody (Mab) specific for BDNF but not by exposure to 5-fold greater concentrations of an irrelevant Mab of the same isotype (IgG1). There was a significant and positive correlation (r = +0.86) between plasma levels of BDNF and serotonin, an indoleamine that is specifically released from activated platelets. These results are consistent with the view that the BDNF detected in human and rat plasma is derived from platelet degranulation, and that circulating levels of BDNF are negligible. In contrast to human or rat serum, mouse serum contained no detectable BDNF. However, BDNF protein was readily detectable at 108-256 ng/g of tissue in hippocampus, frontal cortex, and neostriatum of mice and rats. Thus, the failure to detect BDNF in murine serum was not due to an assay defect but highlights a significant species difference in the tissue-specific expression of BDNF that may be of biological importance. The presence of BDNF protein in blood and brain regions at quantities which greatly exceed those described for NGF confirm the abundant distribution of this broadly-acting neurotrophic factor.