[HTML][HTML] Distinct subpopulations of FOXD1 stroma-derived cells regulate renal erythropoietin

H Kobayashi, Q Liu, TC Binns… - The Journal of …, 2016 - Am Soc Clin Investig
H Kobayashi, Q Liu, TC Binns, AA Urrutia, O Davidoff, PP Kapitsinou, AS Pfaff, H Olauson
The Journal of clinical investigation, 2016Am Soc Clin Investig
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 …
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.
The Journal of Clinical Investigation