Cell density dependent effects of TGF-beta demonstrated by a plasminogen activator-based assay for TGF-beta.
Cell density dependent effects of TGF-beta demonstrated by a plasminogen activator-based assay for TGF-beta.
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基于纤溶酶原激活剂的 TGF-β 测定证明了 TGF-β 的细胞密度依赖性效应。
DOI：
10.1002/jcp.1041520107
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发表时间：
1992
影响因子：
5.6
通讯作者：
Rifkin,DB
中科院分区：
文献类型：
--
作者：
Flaumenhaft,R;Rifkin,DB
转化生长因子-β1（TGF-β1）诱导牛主动脉内皮（BAE）细胞融合培养物中纤溶酶原激活物（PA）表达降低。我们描述了一种使用TGF-β1抑制融合BAE细胞中PA表达的试验，其检测生长因子浓度范围为5 - 200 pg/ml，ED 50为15-20 pg/ml。该试验可在96孔板中进行，每份样品至少需要35 ul溶液，从而限制了所需试剂的量，并允许在单次试验中检测许多样品。在这里，我们证明了TGF-β1对BAE细胞中PA表达的影响取决于细胞暴露于生长因子的时间长度和细胞接种的密度。在高密度（3.5 × 105 cells/cm 2）培养的细胞中，TGF-β1暴露4 h和24 h均抑制PA表达。然而，在细胞稀疏接种（3.5 × 104个细胞/cm 2）的情况下，接触TGF-β1 4小时可使PA表达增加2倍，而接触24小时可导致基础PA表达抑制85%。TGF-β1暴露4 h后，稀疏密度细胞中PA表达的反常刺激以剂量依赖性方式发生，ED 50为15-20 pg/ml。在暴露于TGF-β1的细胞中PA产生的这种双功能反应可能与TGF-β1在血管生成中的作用有关。© 1992 Wiley利斯公司
Transforming growth factor‐β1 (TGF‐β1) induces a decrease in plasminogen activator (PA) expression in confluent cultures of bovine aortic endothelial (BAE) cells. We describe an assay using the suppression of PA expression in confluent BAE cells by TGF‐β1 which detects concentrations of the growth factor ranging from 5 to 200 pg/ml and has an ED50of 15–20 pg/ml. The assay can be performed in 96‐well plates and requires a minimum of 35 ul of solution per sample, thereby limiting the amount of reagents required and allowing many samples to be tested in a single assay. Here we demonstrate that the effect of TGF‐β1 on PA expression in BAE cells depends on the length of time the cells are exposed to the growth factor and the density at which the cells are plated. In cells plated at a high density (3.5 × 105cells/cm2), both 4 h and 24 h exposures to TGF‐β1 suppress PA expression. However, with cells plated sparsely (3.5 × 104cells/cm2), a 4 h exposure to TGF‐β1 increases PA expression 2‐fold, whereas a 24 h exposure results in an 85% inhibition of basal PA expression. The paradoxical stimulation of PA expression in cells at a sparse density upon 4 h exposure to TGF‐β1 occurs in a dose‐dependent manner with an ED50of 15–20 pg/ml. This bifunctional response of PA production in cells exposed to TGF‐β1 may have implications with regard to the role of TGF‐β1 in angiogenesis. © 1992 Wiley‐Liss, Inc.