Characterization of Fatty Acid Binding Protein 7 (FABP7) in the Murine Retina

• Published in: Investigative ophthalmology & visual science Vol. 57; no. 7; pp. 3397 - 3408
• Main Authors: Su, Xinyi, Tan, Queenie S W, Parikh, Bhav H, Tan, Alison, Mehta, Milan N, Sia Wey, Yeo, Tun, Sai Bo Bo, Li, Ling-Jun, Han, Xiao-Yan, Wong, Tien Y, Hunziker, Walter, Luu, Chi D, Owada, Yuji, Barathi, Veluchamy A, Zhang, Samuel S, Chaurasia, Shyam S
• Format: Journal Article
• Language: English
• Published: United States 01.06.2016
• Subjects: Animals; Blood Glucose - analysis; Blotting, Western; Disease Models, Animal; Electroretinography; Fatty Acid-Binding Protein 7 - deficiency; Fatty Acid-Binding Protein 7 - metabolism; Fluorescein Angiography; Immunohistochemistry; Mice; Mice, Inbred C57BL; Mice, Knockout; Real-Time Polymerase Chain Reaction; Retina - metabolism; Retina - physiopathology; Retinal Degeneration - metabolism; Retinal Degeneration - physiopathology; Retinal Vessels - physiopathology; Tomography, Optical Coherence
• ISSN: 1552-5783; 1552-5783
• DOI: 10.1167/iovs.15-18542

To characterize the mouse retina lacking fatty acid binding protein (FABP7-/-). Immunohistochemistry (IHC) was performed in 8-week-old mice to localize FABP7 in the retina. Retinal thickness was measured using image-guided spectral-domain optical coherence topography images. Electroretinography was carried out to assess retinal function. Fundus photography and fundus fluorescein angiography were performed on FABP7-/- and littermate wild-type (WT) mice, and retinal vascular changes were calculated using Singapore I Vessel Assessment (SIVA) analysis. Blood glucose levels were measured in the 8-week-old WT and FABP7-/- mice. In addition, retina was processed for trypsin digestion and retinal flat mounts for isolectin staining. Transcript levels of FABP7, VEGF, GFAP, and Na+K+ATPase were quantified using real-time PCR, and protein expression was analyzed by IHC and Western blot. Fatty acid binding protein 7 is expressed in the inner nuclear layer, outer plexiform layer, and photoreceptor inner segments. No significant difference in retinal thickness and ERG responses was observed between FABP7-deficient and WT retinas. FABP7-/- mice have significantly decreased retinal venular caliber retinal arteriolar fractal dimension compared with WT littermates. FABP7-/- mice showed significant increased areas of fluorescein leakage in the retina. FABP7-/- mice exhibited elevated high blood glucose levels compared with WT mice. Trypsin digested FABP7-/- mice retina showed increased acellular strands and endothelial cell drop outs, and reduced microvasculature branching compared with WT retina. FABP7-/- mice retina also have increased GFAP and VEGF expression. Fatty acid binding protein 7 is expressed in the retina and might play an important role in maintaining retinal vasculature.