Gene expression profiling of TGFbeta2- and/or BMP7-treated trabecular meshwork cells: Identification of Smad7 as a critical inhibitor of TGF-beta2 signaling.
Gene expression profiling of TGFbeta2- and/or BMP7-treated trabecular meshwork cells: Identification of Smad7 as a critical inhibitor of TGF-beta2 signaling.
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DOI：
10.1016/j.exer.2009.01.002
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发表时间：
2009-06
影响因子：
3.4
通讯作者：
Tamm, Ernst R.
中科院分区：
文献类型：
--
作者：
Fuchshofer, Rudolf;Stephan, Dietrich A.;Russell, Paul;Tamm, Ernst R.
原发性开角型青光眼（POAH）患者的小梁网（TM）中的一个明显结构变化是TM的前小管区域中纤维状细胞外基质（ECM）的增加。转化生长因子（TGF）-β2信号可能参与其中，因为TGF-β2在POAG患者的房水中显著增加。在培养的人TM细胞中，TGF-β2导致ECM沉积增加，如果将BMP 7与TGF-β2组合加入，则该作用被减弱或阻止。为了进一步了解BMP 7、TGF-β2或二者联合作用诱导的HTM细胞信号网络，我们通过微阵列分析鉴定了差异表达的基因，并通过定量RT-PCR、Western blotting或免疫组化证实了所选基因。我们观察到TGF-β2和BMP 7对相当多的基因表达的多重影响，这些基因参与生长因子信号传导、ECM结构和周转以及细胞骨架的修饰。在被发现受到调节的基因中有CAPZA 1、CDC 42 BPB、EFEMP 1、FGF 5、FSTL 3、HBEGF、LTBP 1、LTBP 2、MATN 2、NRP 1、SERPINE 1、SH 3 MD 1、SMTN、SMAD 7、TFPI 2、TNFAIP 6和VEGF。由于SMAD 7编码Smad 7（一种抑制性Smad，其在负反馈回路中起作用以抑制TGF-β活性），我们通过特异性小干扰RNA使培养的人TM细胞中的Smad 7 mRNA沉默。其mRNA的沉默导致TM细胞中Smad 7的大量敲低。BMP-7/TGF-β2联合应用后，BMP-7对TGF-β2诱导的CTGF表达的拮抗作用消失。结论：Smad 7是TM细胞中抑制TGF-β2信号转导的关键分子开关，并介导BMP 7对TGF-β2的钝化作用。Smad 7的治疗性调节可能是影响TM中ECM周转和治疗POAG的有前途的方法。
A distinct structural change in the trabecular meshwork (TM) of patients with primary open-angle glaucoma (POAH) is the increase in fibrillar extracellular matrix (ECM) in the juxtacanalicular region of the TM. Transforming growth factor (TGF)-β2 signaling may be involved, as TGF-β2 is significantly increased in the aqueous humor of patients with POAG. In cultured human TM cells, TGF-β2 causes an increase in ECM deposition, an effect that is blunted or prevented, if BMP7 is added in combination with TGF-β2. In order to know more about the signaling network that is induced in HTM cells treated with BMP7, TGF-β2 or the combination of both factors, we identified differentially regulated genes by microarray analysis, and confirmed selected genes by quantitative RT-PCR, Western blotting, or immunohistochemistry. We observed multiple effects of both TGF-β2 and BMP7 on the expression of a considerable number of genes involved in growth factor signaling, ECM structure and turnover, and modification of the cytoskeleton. Among the genes that were found to be regulated were CAPZA1, CDC42BPB, EFEMP1, FGF5, FSTL3, HBEGF, LTBP1, LTBP2, MATN2, NRP1, SERPINE1, SH3MD1, SMTN, SMAD7, TFPI2, TNFAIP6, and VEGF. Since SMAD7 encodes for Smad7, an inhibitory Smad that acts in a negative feedback loop to inhibit TGF-β activity, we silenced Smad7 mRNA in cultured human TM cells by a specific small interfering RNA. Silencing of its mRNA caused a substantial knock down of Smad7 in TM cells. Following combined BMP7/TGF-β2 treatment, the antagonizing effect of BMP7 on TGF-β2 induced CTGF expression was abolished. We conclude that Smad7 is the key molecular switch that inhibits TGF-β2 signaling, and mediates the blunting effects of BMP7 on TGF-β2 in TM cells. A therapeutic modulation of Smad7 might be a promising approach to influence ECM turnover in the TM and to treat POAG.
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影响因子：
3.4
作者：
Flügel-Koch, C;Ohlmann, A;Tamm, ER
通讯作者：
Tamm, ER
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通讯作者：
Tamm, Ernst R.
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