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Yokomizo H, Maeda Y, Park K, Clermont AC, Hernandez SL, Fickweiler W, Li Q, Wang CH, Paniagua SM, Simao F, Ishikado A, Sun B, Wu IH, Katagiri S, Pober DM, Tinsley LJ, Avery RL, Feener EP, Kern TS, Keenan HA, Aiello LP, Sun JK, King GL. Retinol binding protein 3 is increased in the retina of patients with diabetes resistant to diabetic retinopathy. Sci Transl Med 2020; 11:11/499/eaau6627. [PMID: 31270273 DOI: 10.1126/scitranslmed.aau6627] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 01/18/2019] [Accepted: 05/31/2019] [Indexed: 12/15/2022]
Abstract
The Joslin Medalist Study characterized people affected with type 1 diabetes for 50 years or longer. More than 35% of these individuals exhibit no to mild diabetic retinopathy (DR), independent of glycemic control, suggesting the presence of endogenous protective factors against DR in a subpopulation of patients. Proteomic analysis of retina and vitreous identified retinol binding protein 3 (RBP3), a retinol transport protein secreted mainly by the photoreceptors, as elevated in Medalist patients protected from advanced DR. Mass spectrometry and protein expression analysis identified an inverse association between vitreous RBP3 concentration and DR severity. Intravitreal injection and photoreceptor-specific overexpression of RBP3 in rodents inhibited the detrimental effects of vascular endothelial growth factor (VEGF). Mechanistically, our results showed that recombinant RBP3 exerted the therapeutic effects by binding and inhibiting VEGF receptor tyrosine phosphorylation. In addition, by binding to glucose transporter 1 (GLUT1) and decreasing glucose uptake, RBP3 blocked the detrimental effects of hyperglycemia in inducing inflammatory cytokines in retinal endothelial and Müller cells. Elevated expression of photoreceptor-secreted RBP3 may have a role in protection against the progression of DR due to hyperglycemia by inhibiting glucose uptake via GLUT1 and decreasing the expression of inflammatory cytokines and VEGF.
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Affiliation(s)
- Hisashi Yokomizo
- Research Division, Joslin Diabetes Center, Boston, MA 02215, USA
| | - Yasutaka Maeda
- Research Division, Joslin Diabetes Center, Boston, MA 02215, USA
| | - Kyoungmin Park
- Research Division, Joslin Diabetes Center, Boston, MA 02215, USA
| | - Allen C Clermont
- Research Division, Joslin Diabetes Center, Boston, MA 02215, USA.,Beetham Eye Institute, Joslin Diabetes Center, Boston, MA 02215, USA
| | | | - Ward Fickweiler
- Research Division, Joslin Diabetes Center, Boston, MA 02215, USA.,Beetham Eye Institute, Joslin Diabetes Center, Boston, MA 02215, USA
| | - Qian Li
- Research Division, Joslin Diabetes Center, Boston, MA 02215, USA
| | - Chih-Hao Wang
- Research Division, Joslin Diabetes Center, Boston, MA 02215, USA
| | | | - Fabricio Simao
- Research Division, Joslin Diabetes Center, Boston, MA 02215, USA
| | - Atsushi Ishikado
- Research Division, Joslin Diabetes Center, Boston, MA 02215, USA
| | - Bei Sun
- Research Division, Joslin Diabetes Center, Boston, MA 02215, USA
| | - I-Hsien Wu
- Research Division, Joslin Diabetes Center, Boston, MA 02215, USA
| | - Sayaka Katagiri
- Research Division, Joslin Diabetes Center, Boston, MA 02215, USA
| | - David M Pober
- Research Division, Joslin Diabetes Center, Boston, MA 02215, USA
| | - Liane J Tinsley
- Research Division, Joslin Diabetes Center, Boston, MA 02215, USA
| | - Robert L Avery
- California Retina Consultants, Santa Barbara, CA 93103, USA
| | - Edward P Feener
- Research Division, Joslin Diabetes Center, Boston, MA 02215, USA.,Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Timothy S Kern
- Center for Translational Vision Research, Gavin Herbert Eye Institute, Irvine, CA 92697, USA
| | - Hillary A Keenan
- Research Division, Joslin Diabetes Center, Boston, MA 02215, USA.,Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Lloyd Paul Aiello
- Research Division, Joslin Diabetes Center, Boston, MA 02215, USA.,Beetham Eye Institute, Joslin Diabetes Center, Boston, MA 02215, USA.,Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA
| | - Jennifer K Sun
- Research Division, Joslin Diabetes Center, Boston, MA 02215, USA.,Beetham Eye Institute, Joslin Diabetes Center, Boston, MA 02215, USA.,Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA
| | - George L King
- Research Division, Joslin Diabetes Center, Boston, MA 02215, USA. .,Department of Medicine, Harvard Medical School, Boston, MA 02115, USA.,Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA
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Gonzalez-Fernandez F, Betts-Obregon B, Tsin AT, DeSa RJ. Technical brief: Pump-probe paradigm in an integrating cavity to study photodecomposition processes. Mol Vis 2016; 22:953-8. [PMID: 27559291 PMCID: PMC4974848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Accepted: 08/03/2016] [Indexed: 11/12/2022] Open
Abstract
PURPOSE Assaying photodecomposition is challenging because light must be used to initiate the photodamage and light must be used to monitor the photodecomposition. The experimental requirements are as follows: 1) During exposure of the actinic beam, continuously monitor the spectral characteristics of the sample, 2) uniformly expose the reactants to the actinic source, 3) obtain informative spectra in the presence of light scatter, and 4) achieve sufficient sensitivity for dilute reactants. Traditional spectrophotometers cannot address these issues due to sample turbidity, the inability to uniformly expose the cuvette contents to the incident beam, the inability to simultaneously perform spectral scans, and inherent low sensitivity. Here, we describe a system that meets these challenges in a practical way. METHODS Light access to a 8.6 ml quartz integrating sphere containing 10 µM all-trans retinol in PBS was provided by three ports at right angles allowing for the following: 1) actinic light delivery from light-emitting diodes (LEDs) firing at 100 pulses/sec, 2) entry of a separate scanning beam at 100 scans/sec (10,000 µsec scan time) via an OLIS RSM 1000 ultraviolet/visual (UV/Vis) rapid-scanning spectrophotometer (RSM), and 3) light exit to the detector photomultiplier. The RSM spectral intermediate slit was partially covered to allow for a "dark" period of 2,000 µsec when no scanning light was admitted to the cuvette. During that interval, the LED was flashed, and the photomultiplier was temporarily blocked by a perforated spinning shutter disk. The absorbance per centimeter, which is increased due to the internal reflectance of the integrating sphere compared to a standard 1 cm rectangular cuvette, was calculated according to Fry et al. (2010) Applied Optics 49:575. Retinoid photodecomposition was confirmed with high-performance liquid chromatography (HPLC). RESULTS Using the RSM to trigger the LED flash and photomultiplier shutter closure during the "dark" period allowed actinic flashes to be placed between scans. Exposure of the all-trans retinol to 366 nm flashes resulted in marked reduction in absorbance and a blue shift of the λmax. A white LED, despite its higher photon output, did not support all-trans retinol photolysis. Singular value decomposition (SVD) analysis revealed three spectral intermediates with mechanism, I -> II -> III. HPLC analysis of the reactants at the beginning and the conclusion of the light exposure confirmed the retinol photodecomposition. CONCLUSIONS The highly reflecting cavity acts as a multipass cuvette that markedly increased the light path length and, thus, sensitivity. Triggering the LED during a dark period within the scan time allowed the actinic flashes to be interleafed between scans in a pump-probe paradigm. Furthermore, the entire sample was exposed to scan beam and actinic flashes, which is not possible in traditional spectrophotometers. Finally, the integrating cavity cuvette allowed use of turbid samples. SVD was useful for resolving spectral intermediates. Although the identity of the intermediates was not determined here, the ability to define molecular intermediates during photodecomposition reactions will allow future studies to isolate and identify the degradation products and determine the mechanism of light-induced retinoid degradation and that of retinoid-binding protein-mediated photoprotection.
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Affiliation(s)
- Federico Gonzalez-Fernandez
- Departments of Ophthalmology and Pathology, University of Mississippi Medical Center, Jackson, MS,Research & Development Service, G.V. (Sonny) Montgomery Veterans Affair Medical Center, Jackson, MS
| | | | - Andrew T. Tsin
- Department of Biology, The University of Texas at San Antonio, San Antonio, TX
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