Purpose: The purpose of this study was to clarify the localization and function of the ATP-binding cassette transporter G2 (ABCG2; BCRP/MXR/ABCP) in retinal capillary endothelial cells, which form the inner blood-retinal barrier, as an efflux transport system.
Methods: The expression was determined by reverse transcriptase polymerase chain reaction and Western blotting. The localization was identified by immunostaining. The transport function of ABCG2 was measured by flow cytometry.
Results: Western blotting indicated that ABCG2 was expressed as a glycosylated disulfide-linked complex in the mouse retina and in peripheral tissues, including liver, kidney, and small intestine. Double immunolabeling of ABCG2 and glucose transporter 1 suggested that ABCG2 was localized on the luminal membrane of mouse retinal capillary endothelial cells. ABCG2 mRNA and protein were found to be expressed in a conditionally immortalized rat retinal capillary endothelial cell line, TR-iBRB, and rat retina. Treatment with Ko143, an ABCG2 inhibitor, restored the accumulation of pheophorbide a and protoporphyrin IX in TR-iBRB cells.
Conclusion: ABCG2 is expressed on the luminal membrane of retinal capillary endothelial cells, where ABCG2 acts as the efflux transporter for photosensitive toxins such as pheophorbide a and protoporphyrin IX. ABCG2 could play an important role at the inner blood-retinal barrier in restricting the distribution of phototoxins and xenobiotics in retinal tissue.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1007/s11095-006-0067-2 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Normalized Reflectivity of Middle Limiting Membrane on SD-OCT: A Measure of Acute Ischemia in CRVO.
Curr Eye Res
January 2025
Department of Ophthalmology, University Medical Center Goettingen, Goettingen, Germany.
Purpose: To validate the quantification of the prominent middle limiting membrane (PMLM) sign, a marker of mild-to-moderate acute ischemic damage on optical coherence tomography (OCT), by measuring middle limiting membrane (MLM) reflectivity in patients with central retinal vein occlusion (CRVO) and to investigate the prognostic impact of this measure.
Methods: Spectral Domain (SD)-OCT B-scans of 30 patients with CRVO, either sole CRVO or combined central retinal artery and vein occlusion (CCRAVO), were analyzed retrospectively and graded as PMLM present or absent. Normalized MLM reflectivity was calculated as a ratio of the maximum reflectivity within a MLM target layer and the average reflectivity of the retinal pigment epithelium (RPE).
Coats-Like reaction post-vitreoretinal surgery for PDR managed with laser photocoagulation and adjunctive intravitreal steroids- a case report.
BMC Ophthalmol
January 2025
Dept. of Retina and Vitreous, Narayana Nethralaya, #121/C, 1st R Block, Chord Road, Rajaji Nagar, Bengaluru, 560010, India.
Purpose: To report a rare case of a Coats-like response developing after vitreoretinal surgery for proliferative diabetic retinopathy (PDR) and its successful management with retinal laser photocoagulation and adjunctive intravitreal steroids.
Case Description: A 52-year-old woman with a five-year history of type 2 diabetes mellitus and hypertension presented with decreased vision in the left eye (counting fingers at 1 m). Examination revealed high-risk PDR in both eyes, with a subtotal macula-off combined retinal detachment in the left eye.
Structural and vascular assessment of the optic nerve head and macula in chronic Chagas disease.
Sci Rep
January 2025
Department of Ophthalmology, Federal University of São Paulo, São Paulo, SP, Brazil.
Chagas disease (CD), a parasitic infection, may have ocular repercussions in its cardiologic form, since a history of heart disease of other etiologies already has been established as a risk factor for neuropathies and maculopathies. The aim of the present study was to investigate preclinical structural and vascular optic nerve head (ONH) and macular parameters in patients with chronic CD. Nineteen patients with CD and 19 healthy subjects were evaluated with optical coherence tomography, optical coherence tomography angiography, and Laguna ONhE® software.
View Article and Find Full Text PDFSecretogranin III: a promising therapeutic target for intraocular neovascular lesions.
Int Ophthalmol
January 2025
Department of Ophthalmology, The Second Hospital of Jilin University, #218 Ziqiang Street, Changchun, 130041, Jilin, China.
Purpose: The purpose of this study is to investigate the role of Secretogranin III (Scg3) in the pathogenesis of intraocular neovascular diseases and assess its potential as a therapeutic target for novel treatment strategies.
Methods: A literature review was conducted to examine the expression of Scg3 in intraocular neovascular diseases. We reviewed studies on the interaction of Scg3 with its homologous receptors and its effect on endothelial cell proliferation, migration, and vascular permeability-key processes involved in angiogenesis and neovascularization.
Evaluation of Retinal and Choroidal Microvascularity in Patients with Benign Essential Blepharospasm.
Curr Eye Res
January 2025
University of Health Sciences, Basaksehir Cam and Sakura City Hospital, Istanbul, Turkey.
Purpose: To assess the retinal and choroidal microvascular changes in patients with benign essential blepharospasm (BEB) and to investigate the factors that may be effective on microvascularity.
Methods: This study included patients with BEB and healthy controls. All participants underwent a comprehensive examination followed by optical coherence tomography angiography (OCTA).
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!