Endothelin-1 - Mediated signaling in the expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases in astrocytes
Endothelin-1 - Mediated signaling in the expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases in astrocytes
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DOI：
10.1167/iovs.06-1138
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发表时间：
2007-08-01
影响因子：
4.4
通讯作者：
Yorio, Thomas
中科院分区：
文献类型：
--
作者：
He, Shaoqing;Prasanna, Ganesh;Yorio, Thomas
目的.在青光眼患者和青光眼动物模型中，房水和玻璃体液中内皮素（ET）-1水平升高。升高的ET-1是否诱导视神经乳头细胞外基质（ECM）重塑仍不清楚。本研究旨在探讨基质金属蛋白酶/基质金属蛋白酶组织抑制剂（MMPs/TIMPs）对ET-1激活的人视神经乳头星形胶质细胞（hONAs）细胞外基质（ECM）重塑的调节作用。原代hONA暴露于ET-1 1 1天和4天。对孵育培养基进行酶谱分析和Western印迹以检测MMPs和TIMPs的活性和表达。纤维连接蛋白（FN）通过免疫印迹和免疫荧光染色进行监测。ET-1可增加hONAs中MMP-2的活性及TIMP-1、TIMP-2的表达。应用丝裂原活化蛋白激酶（MAPK）或PKC抑制剂可抑制ET-1诱导的TIMP-1和TIMP-2的表达，从而增强MMP-2的活性。用小分子干扰RNA（siRNA）敲低MMP-2，不仅降低MMP-2的活性，而且降低TIMP-1和TIMP-2的表达。ET-1可增加可溶性FN表达及FN基质形成。然而，sFN的积累并没有增强FN基质的形成。与ET-1对MMP-2的影响不同，阻断MAPK和PKC并不改变hONAs中FN的表达和沉积模式。ET-1增加MMP-2、TIMP-1和-2的表达和活性。ERK-MAPK和PKC通路参与MMP-2和TIMP-1和TIMP-2表达的调节。ET-1对MMPs/TIMPs的影响可能不仅在调节MMPs和TIMPs的表达方面起重要作用，而且在影响ECM重塑方面起重要作用。
PURPOSE. Endothelin (ET)-1 levels are increased in aqueous and vitreous humor in patients with glaucoma and animal models of glaucoma. Whether the elevated ET-1 induces extracellular matrix (ECM) remodeling in the optic nerve head is still unknown. In the present study, the regulation of matrix metallo-proteinases/tissue inhibitors of matrix metalloproteinases (MMPs/TIMPs) and ECM remodeling in ET-1-activated human optic nerve head astrocytes (hONAs) were determined.METHODS. Primary hONAs were exposed to ET-1 for 1 day and 4 days. Incubation media were subjected to zymography and Western blot to detect activity and expression of MMPs and TIMPs. Fibronectin (FN) was monitored by Western blot and immunofluorescent staining.RESULTS. ET-1 increased the activity of MMP-2 and the expression of TIMP-1 and -2 in hONAs. The expression of TIMP-1 and -2 induced by ET-1 was abolished by application of inhibitors of mitogen-activated protein kinase (MAPK) or PKC, leading to enhanced activity of MMP-2. Knockdown of MMP-2, by using small interfering (si) RNA, not only decreased the activity of MMP-2 but also decreased the expression of TIMP-1 and -2. ET-1 increased the soluble (s)FN expression as well as FN matrix formation. However, the accumulation of sFN did not enhance FN matrix formation. Unlike ET-1's effects on MMP-2, blockade of MAPK and PKC did not alter the expression and deposition pattern of FN in hONAs.CONCLUSIONS. ET-1 increased the expression and activity of MMP-2 and TIMP-1 and -2. The ERK-MAPK and PKC pathways are involved in the regulation of expression of MMP-2 and TIMP-1 and -2. ET-1's effects on MMPs/TIMPs may be important, not only in regulating the expression of MMPs and TIMPs, but also in influencing ECM remodeling.