Fibroblast growth factor 23 (FGF23) is a bone-derived hormone that controls blood phosphate levels by increasing renal phosphate excretion and reducing 1,25-dihydroxyvitamin D3 [1,25(OH)2D] production. Disorders of FGF23 homeostasis are associated with significant morbidity and mortality, but a fundamental understanding of what regulates FGF23 production is lacking. Because the kidney is the major end organ of FGF23 action, we hypothesized that it releases a factor that regulates FGF23 synthesis. Using aptamer-based proteomics and liquid chromatography–mass spectrometry–based (LC-MS–based) metabolomics, we profiled more than 1600 molecules in renal venous plasma obtained from human subjects. Renal vein glycerol-3-phosphate (G-3-P) had the strongest correlation with circulating FGF23. In mice, exogenous G-3-P stimulated bone and bone marrow FGF23 production through local G-3-P acyltransferase–mediated (GPAT-mediated) lysophosphatidic acid (LPA) synthesis. Further, the stimulatory effect of G-3-P and LPA on FGF23 required LPA receptor 1 (LPAR1). Acute kidney injury (AKI), which increases FGF23 levels, rapidly increased circulating G-3-P in humans and mice, and the effect of AKI on FGF23 was abrogated by GPAT inhibition or Lpar1 deletion. Together, our findings establish a role for kidney-derived G-3-P in mineral metabolism and outline potential targets to modulate FGF23 production during kidney injury.
Petra Simic, Wondong Kim, Wen Zhou, Kerry A. Pierce, Wenhan Chang, David B. Sykes, Najihah B. Aziz, Sammy Elmariah, Debby Ngo, Paola Divieti Pajevic, Nicolas Govea, Bryan R. Kestenbaum, Ian H. de Boer, Zhiqiang Cheng, Marta Christov, Jerold Chun, David E. Leaf, Sushrut S. Waikar, Andrew M. Tager, Robert E. Gerszten, Ravi I. Thadhani, Clary B. Clish, Harald Jüppner, Marc N. Wein, Eugene P. Rhee
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