TY - JOUR
T1 - Human retinal pigment epithelial cells prefer proline as a nutrient and transport metabolic intermediates to the retinal side
AU - Chao, Jennifer R.
AU - Knight, Kaitlen
AU - Engel, Abbi L.
AU - Jankowski, Connor
AU - Wang, Yekai
AU - Manson, Megan A.
AU - Gu, Haiwei
AU - Djukovic, Danijel
AU - Raftery, Daniel
AU - Hurley, James B.
AU - Du, Jianhai
N1 - Funding Information:
This work was supported by National Institutes of Health Grants EY026030 (to J. D., J. B. H., and J. R. C.), EY06641 and EY017863 (to J. B. H.), and EY019714 (to J. R. C.) and the Brightfocus Foundation (to J. D. and J. R. C.). The authors declare that they have no conflicts of interest with the contents of this article. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. We thank Dr. Martin Sadiliek, the director of the University of Washington Chemistry Mass Spectrometry Facility, for assistance with GC-MS analysis.
Publisher Copyright:
© 2017 by The American Society for Biochemistry and Molecular Biology, Inc.
PY - 2017/8/4
Y1 - 2017/8/4
N2 - Metabolite transport is a major function of the retinal pigment epithelium (RPE) to support the neural retina. RPE dysfunction plays a significant role in retinal degenerative diseases. We have used mass spectrometry with 13C tracers to systematically study nutrient consumption and metabolite transport in cultured human fetal RPE. LC/MS-MS detected 120 metabolites in the medium from either the apical or basal side. Surprisingly, more proline is consumed than any other nutrient, including glucose, taurine, lipids, vitamins, or other amino acids. Besides being oxidized through the Krebs cycle, proline is used to make citrate via reductive carboxylation. Citrate, made either from 13C proline or from 13C glucose, is preferentially exported to the apical side and is taken up by the retina. In conclusion, RPE cells consume multiple nutrients, including glucose and taurine, but prefer proline, and they actively synthesize and export metabolic intermediates to the apical side to nourish the outer retina.
AB - Metabolite transport is a major function of the retinal pigment epithelium (RPE) to support the neural retina. RPE dysfunction plays a significant role in retinal degenerative diseases. We have used mass spectrometry with 13C tracers to systematically study nutrient consumption and metabolite transport in cultured human fetal RPE. LC/MS-MS detected 120 metabolites in the medium from either the apical or basal side. Surprisingly, more proline is consumed than any other nutrient, including glucose, taurine, lipids, vitamins, or other amino acids. Besides being oxidized through the Krebs cycle, proline is used to make citrate via reductive carboxylation. Citrate, made either from 13C proline or from 13C glucose, is preferentially exported to the apical side and is taken up by the retina. In conclusion, RPE cells consume multiple nutrients, including glucose and taurine, but prefer proline, and they actively synthesize and export metabolic intermediates to the apical side to nourish the outer retina.
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U2 - 10.1074/jbc.M117.788422
DO - 10.1074/jbc.M117.788422
M3 - Article
C2 - 28615447
AN - SCOPUS:85026743271
VL - 292
SP - 12895
EP - 12905
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 31
ER -
