Distinct subpopulations of FOXD1 stroma-derived cells regulate renal erythropoietin

J Clin Invest. 2016 May 2;126(5):1926-38. doi: 10.1172/JCI83551. Epub 2016 Apr 18.

Abstract

Renal peritubular interstitial fibroblast-like cells are critical for adult erythropoiesis, as they are the main source of erythropoietin (EPO). Hypoxia-inducible factor 2 (HIF-2) controls EPO synthesis in the kidney and liver and is regulated by prolyl-4-hydroxylase domain (PHD) dioxygenases PHD1, PHD2, and PHD3, which function as cellular oxygen sensors. Renal interstitial cells with EPO-producing capacity are poorly characterized, and the role of the PHD/HIF-2 axis in renal EPO-producing cell (REPC) plasticity is unclear. Here we targeted the PHD/HIF-2/EPO axis in FOXD1 stroma-derived renal interstitial cells and examined the role of individual PHDs in REPC pool size regulation and renal EPO output. Renal interstitial cells with EPO-producing capacity were entirely derived from FOXD1-expressing stroma, and Phd2 inactivation alone induced renal Epo in a limited number of renal interstitial cells. EPO induction was submaximal, as hypoxia or pharmacologic PHD inhibition further increased the REPC fraction among Phd2-/- renal interstitial cells. Moreover, Phd1 and Phd3 were differentially expressed in renal interstitium, and heterozygous deficiency for Phd1 and Phd3 increased REPC numbers in Phd2-/- mice. We propose that FOXD1 lineage renal interstitial cells consist of distinct subpopulations that differ in their responsiveness to Phd2 inactivation and thus regulation of HIF-2 activity and EPO production under hypoxia or conditions of pharmacologic or genetic PHD inactivation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / genetics
  • Basic Helix-Loop-Helix Transcription Factors / metabolism
  • Erythropoietin / biosynthesis*
  • Erythropoietin / genetics
  • Forkhead Transcription Factors / genetics
  • Forkhead Transcription Factors / metabolism*
  • Hypoxia / genetics
  • Hypoxia / metabolism*
  • Hypoxia / pathology
  • Hypoxia-Inducible Factor-Proline Dioxygenases / genetics
  • Hypoxia-Inducible Factor-Proline Dioxygenases / metabolism
  • Kidney / blood supply
  • Kidney / metabolism*
  • Kidney / pathology
  • Mice
  • Mice, Knockout
  • Procollagen-Proline Dioxygenase / genetics
  • Procollagen-Proline Dioxygenase / metabolism
  • Stromal Cells / metabolism
  • Stromal Cells / pathology

Substances

  • Basic Helix-Loop-Helix Transcription Factors
  • Forkhead Transcription Factors
  • Foxd1 protein, mouse
  • Erythropoietin
  • PHD1 protein, mouse
  • PHD3 protein, mouse
  • Procollagen-Proline Dioxygenase
  • Egln1 protein, mouse
  • Hypoxia-Inducible Factor-Proline Dioxygenases