Transferrin receptor 1 is a cellular receptor for human heme-albumin

Commun Biol. 2020 Oct 27;3(1):621. doi: 10.1038/s42003-020-01294-5.

Abstract

Iron is essential for living cells. Uptake of iron-loaded transferrin by the transferrin receptor 1 (CD71, TFR) is a major but not sufficient mechanism and an alternative iron-loaded ligand for CD71 has been assumed. Here, we demonstrate that CD71 utilizes heme-albumin as cargo to transport iron into human cells. Binding and endocytosis of heme-albumin via CD71 was sufficient to promote proliferation of various cell types in the absence of transferrin. Growth and differentiation of cells induced by heme-albumin was dependent on heme-oxygenase 1 (HO-1) function and was accompanied with an increase of the intracellular labile iron pool (LIP). Import of heme-albumin via CD71 was further found to contribute to the efficacy of albumin-based drugs such as the chemotherapeutic Abraxane. Thus, heme-albumin/CD71 interaction is a novel route to transport nutrients or drugs into cells and adds to the emerging function of CD71 as a scavenger receptor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Albumins / metabolism*
  • Antigens, CD / genetics
  • Antigens, CD / metabolism*
  • Biological Transport
  • Cell Line
  • Cell Proliferation
  • Culture Media
  • Gene Expression Regulation
  • Heme Oxygenase-1 / genetics
  • Heme Oxygenase-1 / metabolism*
  • Humans
  • Iron / metabolism*
  • Receptors, Transferrin / genetics
  • Receptors, Transferrin / metabolism*

Substances

  • Albumins
  • Antigens, CD
  • CD71 antigen
  • Culture Media
  • Receptors, Transferrin
  • Iron
  • Heme Oxygenase-1