Involvement of AP-1 and C/EBPβ in upregulation of endothelin B (ETB) receptor expression in a rodent model of glaucoma.
Involvement of AP-1 and C/EBPβ in upregulation of endothelin B (ETB) receptor expression in a rodent model of glaucoma.
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DOI：
10.1371/journal.pone.0079183
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发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Krishnamoorthy RR
中科院分区：
文献类型：
--
作者：
He S;Minton AZ;Ma HY;Stankowska DL;Sun X;Krishnamoorthy RR
先前的研究表明，内皮素B受体（ETB）表达上调，在青光眼啮齿动物模型的神经退行性变中起关键作用。然而，ETB受体表达上调的机制在很大程度上仍然未知。通过启动子报告子实验，我们发现在人类非色素纤毛上皮细胞（HNPE）中，人类ETB启动子区域上游1258bp对ETB受体基因的组成性表达至关重要。ETB受体的- 300 ~ - 1 bp和- 1258 ~ - 600 bp上游启动子区域似乎是转录因子的关键结合区域。此外，在HNPE细胞中过表达c-Jun后，荧光素酶测定和CHIP测定证实了AP-1的关键结合位点位于- 615至- 624 bp上游启动子。过表达C - jun或C/EBPβ均可增强ETB受体启动子活性，表现为ETB受体mRNA和蛋白水平升高。此外，HNPE细胞中C - jun或C/EBPβ的敲低与ETB和ETA受体mRNA水平的降低显著相关。这些观察结果表明，C - jun和C/EBPβ对HNPE细胞中ETB受体的调控表达很重要。在单独的实验中，褐挪威大鼠的一只眼眼压升高，而对应的对侧眼作为对照。眼压升高两周后，眼压升高的眼视网膜神经节细胞（RGC）层C - jun和C/EBPβ的表达增加。在IOP升高眼视网膜激光显微解剖获得的RGC层中，与对侧眼相比，c-Jun、ETA和ETB受体mRNA水平上调了2.2倍、3.1倍和4.4倍。综上所述，这些数据表明转录因子AP-1在高眼压啮齿动物模型中ETB受体的升高中起关键作用。
Previous studies showed that the endothelin B receptor (ETB) expression was upregulated and played a key role in neurodegeneration in rodent models of glaucoma. However, the mechanisms underlying upregulation of ETB receptor expression remain largely unknown. Using promoter-reporter assays, the 1258 bp upstream the human ETB promoter region was found to be essential for constitutive expression of ETB receptor gene in human non-pigmented ciliary epithelial cells (HNPE). The −300 to −1 bp and −1258 to −600 bp upstream promoter regions of the ETB receptor appeared to be the key binding regions for transcription factors. In addition, the crucial AP-1 binding site located at −615 to −624 bp upstream promoter was confirmed by luciferase assays and CHIP assays which were performed following overexpression of c-Jun in HNPE cells. Overexpression of either c-Jun or C/EBPβ enhanced the ETB receptor promoter activity, which was reflected in increased mRNA and protein levels of ETB receptor. Furthermore, knock-down of either c-Jun or C/EBPβ in HNPE cells was significantly correlated to decreased mRNA levels of both ETB and ETA receptor. These observations suggest that c-Jun and C/EBPβ are important for regulated expression of the ETB receptor in HNPE cells. In separate experiments, intraocular pressure (IOP) was elevated in one eye of Brown Norway rats while the corresponding contralateral eye served as control. Two weeks of IOP elevation produced increased expression of c-Jun and C/EBPβ in the retinal ganglion cell (RGC) layer from IOP-elevated eyes. The mRNA levels of c-Jun, ETA and ETB receptor were upregulated by 2.2-, 3.1- and 4.4-fold in RGC layers obtained by laser capture microdissection from retinas of eyes with elevated IOP, compared to those from contralateral eyes. Taken together, these data suggest that transcription factor AP-1 plays a key role in elevation of ETB receptor in a rodent model of ocular hypertension.
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影响因子：
4
作者：
Hess, J;Angel, P;Schorpp-Kistner, M
通讯作者：
Schorpp-Kistner, M
影响因子：
6.1
作者：
Fernandes, Kimberly A.;Harder, Jeffrey M.;Fornarola, Laura B.;Freeman, Robert S.;Clark, Abbot F.;Pang, Iok-Hou;John, Simon W. M.;Libby, Richard T.
通讯作者：
Libby, Richard T.
影响因子：
3.7
作者：
Minton AZ;Phatak NR;Stankowska DL;He S;Ma HY;Mueller BH;Jiang M;Luedtke R;Yang S;Brownlee C;Krishnamoorthy RR
通讯作者：
Krishnamoorthy RR
影响因子：
11.2
作者：
Ji, Y;Studzinski, GP
通讯作者：
Studzinski, GP
影响因子：
3.4
作者：
Lau, J;Dang, M;Ball, AK
通讯作者：
Ball, AK