Energy metabolism and metabolite transport are essential for the viability and function of the retinal pigment epithelium (RPE). Understanding these processes and their perturbations in disease states is of fundamental importance. Our preliminary results show reductive carboxylation is much more prominent in RPE than in retina or other neuronal cells or tissues. We found that reductive carboxylation is deficient in RPE cells derived from induced pluripotent stem cell (iPSC) cells made from a Sorsby's Fundus Dystrophy (SFD) patient and under conditions of oxidative stress, a critical component of early pathogenesis of AMD. Because of the potential disease relevance of reductive carboxylation in RPE cells, we will examine the role of reductive carboxylation in RPE cells using advanced tracer methodology, real time mitochondrial function analysis and live imaging. We observed in a well-controlled cell culture system that human RPE preferentially exports metabolites to the retinal side. We also found that metabolite transport is impaired in SFD iPSC-derived RPE cells. We plan to systematically investigate the regulation of metabolite transport by extracellular structure and intracelluar state, and identify the mechanisms of the defective transport in SFD RPE. This proposed research will generate a reference data set of metabolites that are preferentially exported and consumed by the RPE, determine the role of reductive carboxylation in RPE cell metabolism, and reveal normal and disease-relevant changes in metabolite transport in RPE. This new information can be used to develop treatment of retinal degenerative diseases.

Public Health Relevance

Retinal pigment epithelial (RPE) cells have unique metabolic requirements that are perturbed in disease states. Findings from our studies will provide a framework for understanding what RPE require for viability and function and expedite the understanding of the underlying causes of retinal disease.

National Institute of Health (NIH)
National Eye Institute (NEI)
Research Project (R01)
Project #
Application #
Study Section
Biology of the Visual System Study Section (BVS)
Program Officer
Neuhold, Lisa
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of Washington
Schools of Medicine
United States
Zip Code
Du, Jianhai; An, Jie; Linton, Jonathan D et al. (2018) How Excessive cGMP Impacts Metabolic Proteins in Retinas at the Onset of Degeneration. Adv Exp Med Biol 1074:289-295
Zhu, Siyan; Yam, Michelle; Wang, Yekai et al. (2018) Impact of euthanasia, dissection and postmortem delay on metabolic profile in mouse retina and RPE/choroid. Exp Eye Res 174:113-120
Wang, Yekai; Grenell, Allison; Zhong, Fanyi et al. (2018) Metabolic signature of the aging eye in mice. Neurobiol Aging 71:223-233
Kanow, Mark A; Giarmarco, Michelle M; Jankowski, Connor Sr et al. (2017) Biochemical adaptations of the retina and retinal pigment epithelium support a metabolic ecosystem in the vertebrate eye. Elife 6:
Chao, Jennifer R; Knight, Kaitlen; Engel, Abbi L et al. (2017) Human retinal pigment epithelial cells prefer proline as a nutrient and transport metabolic intermediates to the retinal side. J Biol Chem 292:12895-12905
Du, Jianhai; Yanagida, Aya; Knight, Kaitlen et al. (2016) Reductive carboxylation is a major metabolic pathway in the retinal pigment epithelium. Proc Natl Acad Sci U S A 113:14710-14715