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A drug-tunable Flt23k gene therapy for controlled intervention in retinal neovascularization
Citation
Chen, J and Lin, F-L and Leung, JYK and Tu, L and Wang, J-H and Chuang, Y-F and Li, F and Shen, H-H and Dusting, GJ and Wong, VHY and Lisowski, L and Hewitt, AW and Bui, BV and Zhong, J and Liu, G-S, A drug-tunable Flt23k gene therapy for controlled intervention in retinal neovascularization, Angiogenesis, (September) pp. 1-14. ISSN 0969-6970 (2020) [Refereed Article]
 | PDF (Accepted version) Available from 16 September 2021 705Kb |
Copyright Statement
Copyright 2020 Springer Nature B.V.
DOI: doi:10.1007/s10456-020-09745-7
Abstract
Gene therapies that chronically suppress vascular endothelial growth factor (VEGF) represent a new approach for managing retinal vascular leakage and neovascularization. However, constitutive suppression of VEGF in the eye may have deleterious side effects. Here, we developed a novel strategy to introduce Flt23k, a decoy receptor that binds intracellular VEGF, fused to the destabilizing domain (DD) of Escherichia coli dihydrofolate reductase (DHFR) into the retina. The expressed DHFR(DD)-Flt23k fusion protein is degraded unless "switched on" by administering a stabilizer; in this case, the antibiotic trimethoprim (TMP). Cells transfected with the DHFR(DD)-Flt23k construct expressed the fusion protein at levels correlated with the TMP dose. Stabilization of the DHFR(DD)-Flt23k fusion protein by TMP was able to inhibit intracellular VEGF in hypoxic cells. Intravitreal injection of self-complementary adeno-associated viral vector (scAAV)-DHFR(DD)-Flt23k and subsequent administration of TMP resulted in tunable suppression of ischemia-induced retinal neovascularization in a rat model of oxygen-induced retinopathy (OIR). Hence, our study suggests a promising novel approach for the treatment of retinal neovascularization. Schematic diagram of the tunable system utilizing the DHFR(DD)-Flt23k approach to reduce VEGF secretion. a The schematic shows normal VEGF secretion. b Without the ligand TMP, the DHFR(DD)-Flt23k protein is destabilized and degraded by the proteasome. c In the presence of the ligand TMP, DHFR(DD)-Flt23k is stabilized and sequestered in the ER, thereby conditionally inhibiting VEGF. Green lines indicate the intracellular and extracellular distributions of VEGF. Blue lines indicate proteasomal degradation of the DHFR(DD)-Flt23k protein. Orange lines indicate the uptake of cell-permeable TMP. TMP, trimethoprim; VEGF, vascular endothelial growth factor; ER, endoplasmic reticulum.
Item Details
| Item Type: | Refereed Article |
|---|---|
| Keywords: | gene therapy, diabetic retinopathy, angiogenesis, VEGF, AAV, destabilizing domain, Flt23k, retinal neovascularization, trimethoprim |
| Research Division: | Biomedical and Clinical Sciences |
| Research Group: | Medical biotechnology |
| Research Field: | Gene and molecular therapy |
| Objective Division: | Health |
| Objective Group: | Clinical health |
| Objective Field: | Clinical health not elsewhere classified |
| UTAS Author: | Chen, J (Ms Jane Chen) |
| UTAS Author: | Lin, F-L (Dr Fan-Li Lin) |
| UTAS Author: | Leung, JYK (Dr Jacqueline Leung) |
| UTAS Author: | Chuang, Y-F (Dr Yu-Fan Chuang) |
| UTAS Author: | Li, F (Dr Fan Li) |
| UTAS Author: | Hewitt, AW (Professor Alex Hewitt) |
| UTAS Author: | Liu, G-S (Associate Professor Guei-Sheung Liu) |
| ID Code: | 140994 |
| Year Published: | 2020 |
| Funding Support: | National Health and Medical Research Council (1185600) |
| Deposited By: | Menzies Institute for Medical Research |
| Deposited On: | 2020-09-17 |
| Last Modified: | 2020-10-12 |
| Downloads: | 0 |
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