Enhanced expression of transglutaminase 2 in anterior polar cataracts and its induction by TGF-β in vitro
Enhanced expression of transglutaminase 2 in anterior polar cataracts and its induction by TGF-β in vitro
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DOI：
10.1136/bjo.86.11.1293
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发表时间：
2002-11-01
影响因子：
4.1
通讯作者：
Lee, JH
中科院分区：
文献类型：
--
作者：
Wan, XH;Lee, EH;Lee, JH
背景/目的：转氨酶活性长期以来一直与白内障的形成有关。然而，它如何产生和参与这一过程的确切机制仍不清楚。在此，作者试图检测前极性白内障患者的透镜上皮细胞中是否表达转氨酶2（TGase 2），以确定TGase 2的表达是否由转化生长因子诱导本发明的目的在于检测培养的透镜上皮细胞中的TGF-β（转化生长因子-β），并确定TGase 2是否参与体外透镜上皮细胞中纤连蛋白的交联。采用逆转录-聚合酶链反应、蛋白质印迹分析和免疫组织化学分析检测来自前极性白内障、核性白内障和非白内障透明晶状体的透镜上皮细胞中TGase 2的表达。TGF-β对细胞外TGase 2活性的调节通过纤连蛋白聚合物的形成和荧光素尸胺掺入细胞外基质蛋白来测量。结果：前极性白内障患者透镜上皮细胞中TGase 2 mRNA及其蛋白的表达均明显增强。用TGF-β处理HLE B-3细胞引起TGase 2蛋白、其细胞外活性和纤连蛋白交联的增加。瞬时转染的HLE B-3细胞的TGase 2基因导致的增加生产的纤连蛋白单体和polymer.Conclusions：这项研究表明，TGase 2是过表达的透镜上皮细胞从前极性白内障和TGF-β可能是一个致病因素，在诱导的TGase 2。TGase 2的高表达可能导致细胞外基质蛋白的聚集和交联，并可能参与前极白内障的发生。
Background/aims: Transglutaminase activity has long been implicated in the cataract formation. However, the precise mechanism of how it is produced and involved in this process remains unclear. Here the authors sought to examine whether transglutaminase 2 (TGase 2) is expressed in lens epithelial cells from patients with anterior polar cataracts, to determine whether TGase 2 expression is induced by transforming growth factor (TGF-beta) in cultured lens epithelial cells, and to determine whether TGase 2 participates in the crosslinking of fibronectin in lens epithelial cells in vitro.Methods: Lens epithelial cells from anterior polar cataracts, nuclear cataracts, and non-cataractous clear lenses were examined for the expression of TGase 2 using reverse transcription-polymerise chain reaction, western blot analysis, and immunohistochemical analysis. The modulation of extracellular TGase 2 activity by TGF-beta was measured by the formation of fibronectin polymers and the incorporation of fluorescein cadaverine into extracellular matrix proteins. The effect of TGase 2 overexpression was analysed by immunofluorescence staining and western blot analysis of human lens epithelial HLE B-3 cells transiently transfected with TGase 2 gene.Results: The expression of TGase 2 mRNA and its protein was markedly enhanced in lens epithelial cells from patients with anterior polar cataracts. Treatment of HLE B-3 cells with TGF-beta caused an increase in TGase 2 protein, its extracellular activity, and the crosslinking of fibronectin. Transient transfection of HLE B-3 cells with the TGase 2 gene led to the increased production of fibronectin monomers and polymers.Conclusions: This study shows that TGase 2 is overexpressed in lens epithelial cells from anterior polar cataracts and that TGF-beta may be a causative factor in the induction of TGase 2. The enhanced expression of TGase 2 might cause the accumulation and crosslinking of the extracellular matrix proteins and might play a part in anterior polar cataract development.