Expression of monocarboxylate transporters in rat ocular tissues
Expression of monocarboxylate transporters in rat ocular tissues
复制标题
DOI：
10.1152/ajpcell.00037.2004
复制
发表时间：
2005-02-01
影响因子：
5.5
通讯作者：
Osborne, NN
中科院分区：
文献类型：
--
作者：
Chidlow, G;Wood, JPM;Osborne, NN
本研究的目的是通过结合使用常规和实时RT-PCR、免疫印迹和免疫组织化学来确定单羧酸转运蛋白（MCT）亚型1 - 4在大鼠眼的各种结构中的分布。视网膜样本表达编码所有四种MCT的mRNA。在感光细胞内段、Muller细胞、视网膜毛细血管和两个丛状层中观察到MCT 1免疫反应。MCT 2标记集中在内、外丛状层。MCT 4免疫标记仅存在于视网膜内层，特别是在推定的Muller细胞和丛状层中。未观察到MCT 3标记。视网膜色素上皮（RPE）/脉络膜表达高水平的MCT 1和MCT 3 mRNA，但较低水平的MCT 2和MCT 4 mRNA。MCT 1定位于RPE的顶端，MCT 3定位于RPE的基底膜，而MCT 2染色较弱。尽管在虹膜和睫状体样品中均检测到MCT 1-MCT 4 mRNA，但仅MCT 1和MCT 2蛋白表达。这些存在于虹膜上皮和睫状突的非色素上皮中。MCT 4定位于虹膜睫状体和脉络膜中大血管的平滑肌衬里。在角膜中，在上皮和内皮中可检测到MCT 1和MCT 2 mRNA和蛋白质，而在透镜上皮中发现了MCT 4和较小程度的MCT 1存在的证据。MCT亚型在眼睛中的独特分布表明这些转运蛋白在维持眼功能中发挥关键作用。
The aim of the present study was to determine the distribution of monocarboxylate transporter (MCT) subtypes 1 - 4 in the various structures of the rat eye by using a combination of conventional and real-time RT-PCR, immunoblotting, and immunohistochemistry. Retinal samples expressed mRNAs encoding all four MCTs. MCT1 immunoreactivity was observed in photoreceptor inner segments, Muller cells, retinal capillaries, and the two plexiform layers. MCT2 labeling was concentrated in the inner and outer plexiform layers. MCT4 immunolabeling was present only in the inner retina, particularly in putative Muller cells, and the plexiform layers. No MCT3 labeling could be observed. The retinal pigment epithelium (RPE)/ choroid expressed high levels of MCT1 and MCT3 mRNAs but lower levels of MCT2 and MCT4 mRNAs. MCT1 was localized to the apical and MCT3 to the basal membrane of the RPE, whereas MCT2 staining was faint. Although MCT1 - MCT4 mRNAs were all detectable in iris and ciliary body samples, only MCT1 and MCT2 proteins were expressed. These were present in the iris epithelium and the nonpigmented epithelium of the ciliary processes. MCT4 was localized to the smooth muscle lining of large vessels in the iris-ciliary body and choroid. In the cornea, MCT1 and MCT2 mRNAs and proteins were detectable in the epithelium and endothelium, whereas evidence was found for the presence of MCT4 and, to a lesser extent, MCT1 in the lens epithelium. The unique distribution of MCT subtypes in the eye is indicative of the pivotal role that these transporters play in the maintenance of ocular function.