Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
Drug Metab Dispos. 2013 Feb;41(2):466-74. doi: 10.1124/dmd.112.045674. Epub 2012 Nov 20.
Since there is paucity of information on solute transporters in human ocular tissues, the aim of this study was immunohistochemical and functional characterization of peptide transporters (PEPT), organic cation transporters (OCTs), neutral and basic amino acid transporters (ATB(0,+)), and monocarboxylate transporters (MCTs) in human ocular barriers. Immunohistochemical localization of transporters was achieved using 5-µm-thick paraffin-embedded sections of whole human eyes. In vitro transport studies were carried out across human cornea and sclera-choroid-retinal pigment epithelium (SCRPE) using a cassette of specific substrates in the presence and absence of inhibitors to determine the role of transporters in transtissue solute delivery. Immunohistochemistry showed the expression of PEPT-1, PEPT-2, ATB(0,+), OCT-1, OCT-2, MCT-1, and MCT-3 in human ocular tissues. PEPT-1, PEPT-2, OCT-1, MCT-1, and ATB(0,+) expression was evident in the cornea, conjunctiva, ciliary epithelium, and neural retina. Expression of PEPT-1, PEPT-2, and OCT-1 was evident in choroid tissue as well. OCT-2 expression could be seen in the corneal and conjunctival epithelia, whereas MCT-3 expression was confined to the RPE layer. OCT-2 expression was evident in conjunctival blood vessel walls, whereas PEPT-1, PEPT-2, and OCT-1 were expressed in the choroid. Preliminary transport studies indicated inward transport of Gly-Sar (PEPT substrate), 1-methyl-4-phenylpyridinium (MPP+) (OCT substrate), and l-tryptophan (ATB(0,+) substrate) across cornea as well as SCRPE. For phenylacetic acid (MCT substrate), transporter-mediated inward transport across the cornea and outward transport across SCRPE were evident. Thus, PEPT, OCT, and ATB(0,+) are influx transporters present in human ocular barriers, and they can potentially be used for transporter-guided retinal drug delivery after topical, transscleral, and systemic administrations.
由于人类眼组织中溶质转运体的信息匮乏,本研究旨在对人眼组织中的肽转运体(PEPT)、有机阳离子转运体(OCT)、中性和碱性氨基酸转运体(ATB(0,+))和单羧酸转运体(MCT)进行免疫组织化学和功能特征分析。通过使用 5μm 厚的全人眼石蜡包埋切片进行转运体的免疫组织化学定位。在存在和不存在抑制剂的情况下,通过特定底物的盒式运输研究,在人角膜和巩膜脉络膜视网膜色素上皮(SCRPE)中进行体外转运研究,以确定转运体在跨组织溶质输送中的作用。免疫组织化学显示 PEPT-1、PEPT-2、ATB(0,+)、OCT-1、OCT-2、MCT-1 和 MCT-3 在人眼组织中的表达。PEPT-1、PEPT-2、OCT-1、MCT-1 和 ATB(0,+)的表达在角膜、结膜、睫状上皮和神经视网膜中均可见。PEPT-1、PEPT-2 和 OCT-1 的表达也可见于脉络膜组织。OCT-2 表达可见于角膜和结膜上皮,而 MCT-3 表达局限于 RPE 层。OCT-2 表达可见于结膜血管壁,而 PEPT-1、PEPT-2 和 OCT-1 则在脉络膜中表达。初步转运研究表明甘氨酰-肌氨酸(PEPT 底物)、1-甲基-4-苯基吡啶𬭩(MPP+)(OCT 底物)和 l-色氨酸(ATB(0,+)底物)经角膜向内转运,SCRPE 向外转运。对于苯乙酸(MCT 底物),可见跨角膜的转运体介导的内向转运和跨 SCRPE 的外向转运。因此,PEPT、OCT 和 ATB(0,+) 是存在于人眼屏障中的流入转运体,它们可用于局部、经巩膜和全身给药后的转运体指导的视网膜药物输送。
Invest Ophthalmol Vis Sci. 2017-7-1
Invest Ophthalmol Vis Sci. 2011-7-23
Invest Ophthalmol Vis Sci. 2003-4
Drug Metab Dispos. 2011-2-23
Am J Physiol Cell Physiol. 2005-2
Eur J Pharm Sci. 2009-12-24
Invest Ophthalmol Vis Sci. 2003-11
Materials (Basel). 2015-4-13
Int J Pharm. 2015-6-20
Clin Pharmacokinet. 2015-3
J Pharm Pharmacol. 2013-9-1
Ther Deliv. 2010-9
Invest Ophthalmol Vis Sci. 2011-7-23
Nat Rev Drug Discov. 2010-8
Nat Rev Drug Discov. 2010-3
Neurochem Int. 2009-8-8
J Chromatogr B Analyt Technol Biomed Life Sci. 2009-1-15