Transferrin receptor 1-mediated iron uptake regulates bone mass in mice via osteoclast mitochondria and cytoskeleton

  1. Bhaba K Das
  2. Lei Wang
  3. Toshifumi Fujiwara
  4. Jian Zhou
  5. Nukhet Aykin-Burns
  6. Kimberly J Krager
  7. Renny Lan
  8. Samuel G Mackintosh
  9. Ricky Edmondson
  10. Michael L Jennings
  11. Xiaofang Wang
  12. Jian Q Feng
  13. Tomasa Barrientos
  14. Jyoti Gogoi
  15. Aarthi Kannan
  16. Ling Gao
  17. Weirong Xing
  18. Subburaman Mohan  Is a corresponding author
  19. Haibo Zhao  Is a corresponding author
  1. Southern California Institute for Research and Education, United States
  2. Anhui Medical University, China
  3. Kyushu University Hospital, Japan
  4. University of Arkansas for Medical Sciences, United States
  5. Texas A&M University, United States
  6. Duke University, United States
  7. VA Loma Linda Healthcare System, United States

Abstract

Increased intracellular iron spurs mitochondrial biogenesis and respiration to satisfy high-energy demand during osteoclast differentiation and bone-resorbing activities. Transferrin receptor 1 (Tfr1) mediates cellular iron uptake through endocytosis of iron-loaded transferrin and its expression increases during osteoclast differentiation. Nonetheless, the precise functions of Tfr1 and Tfr1-mediated iron uptake in osteoclast biology and skeletal homeostasis remain incompletely understood. To investigate the role of Tfr1 in osteoclast lineage cells in vivo and in vitro, we crossed Tfrc (encoding Tfr1)-floxed mice with Lyz2 (LysM)-Cre and Cathepsin K (Ctsk)-Cre mice to generate Tfrc conditional knockout mice in myeloid osteoclast precursors (Tfr1ΔLysM) or differentiated osteoclasts (Tfr1ΔCtsk), respectively. Skeletal phenotyping by µCT and histology unveiled a significant increase in trabecular bone mass with normal osteoclast number in long bones of 10-week-old young and 6-month-old adult female but not male Tfr1ΔLysM mice. Although high trabecular bone volume in long bones was observed in both male and female Tfr1ΔCtsk mice, this phenotype was more pronounced in female knockout mice. Consistent with this gender-dependent phenomena, estrogen-deficiency induced by ovariectomy decreased trabecular bone mass in Tfr1ΔLysM mice. Mechanistically, disruption of Tfr1 expression attenuated mitochondrial metabolism and cytoskeletal organization in mature osteoclasts in vitro by attenuating mitochondrial respiration and activation of the Src-Rac1-WAVE regulatory complex (WRC) axis, respectively, leading to decreased bone resorption with little impact on osteoclast differentiation. These results indicate that Tfr1-mediated iron uptake is specifically required for osteoclast function and is indispensable for bone remodeling in a gender-dependent manner.

Data availability

All data generated or analysed during this study are included in the manuscript and supporting file.

Article and author information

Author details

  1. Bhaba K Das

    Long Beach VA Healthcare System, Southern California Institute for Research and Education, Long Beach, United States
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-0256-5489
  2. Lei Wang

    Department of Orthopedics, Anhui Medical University, Hefei, China
    Competing interests
    No competing interests declared.
  3. Toshifumi Fujiwara

    Department of Orthopedic Surgery, Kyushu University Hospital, Fukuoka, Japan
    Competing interests
    No competing interests declared.
  4. Jian Zhou

    Department of Orthopedics, Anhui Medical University, HeFei, China
    Competing interests
    No competing interests declared.
  5. Nukhet Aykin-Burns

    Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, United States
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-8574-4102
  6. Kimberly J Krager

    Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, United States
    Competing interests
    No competing interests declared.
  7. Renny Lan

    Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, United States
    Competing interests
    No competing interests declared.
  8. Samuel G Mackintosh

    Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, United States
    Competing interests
    No competing interests declared.
  9. Ricky Edmondson

    Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, United States
    Competing interests
    No competing interests declared.
  10. Michael L Jennings

    Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, United States
    Competing interests
    No competing interests declared.
  11. Xiaofang Wang

    Department of Biomedical Sciences, Texas A&M University, Dallas, United States
    Competing interests
    No competing interests declared.
  12. Jian Q Feng

    Department of Biomedical Sciences, Texas A&M University, Dallas, United States
    Competing interests
    No competing interests declared.
  13. Tomasa Barrientos

    Department of Orthopedics, Duke University, Durham, United States
    Competing interests
    No competing interests declared.
  14. Jyoti Gogoi

    Long Beach VA Healthcare System, Southern California Institute for Research and Education, Long Beach, United States
    Competing interests
    No competing interests declared.
  15. Aarthi Kannan

    Long Beach VA Healthcare System, Southern California Institute for Research and Education, Long Beach, United States
    Competing interests
    No competing interests declared.
  16. Ling Gao

    Long Beach VA Healthcare System, Southern California Institute for Research and Education, Long Beach, United States
    Competing interests
    No competing interests declared.
  17. Weirong Xing

    Musculoskeletal Disease Center, VA Loma Linda Healthcare System, Loma Linda, United States
    Competing interests
    No competing interests declared.
  18. Subburaman Mohan

    Musculoskeletal Disease Center, VA Loma Linda Healthcare System, Loma Linda, United States
    For correspondence
    Subburaman.Mohan@va.gov
    Competing interests
    Subburaman Mohan, Reviewing editor, eLife.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-0063-986X
  19. Haibo Zhao

    Long Beach VA Healthcare System, Southern California Institute for Research and Education, Long Beach, United States
    For correspondence
    Haibo.zhao@va.gov
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-0836-7555

Funding

Southern California Institute for Research and Education (R01AR073298)

  • Haibo Zhao

Loma Linda Veterans Association for Research and Education (R01AR078843)

  • Weirong Xing

Loma Linda Veterans Association for Research and Education (R01AR048139,AR070806)

  • Subburaman Mohan

Loma Linda VA Healthcare System (VA merit BX005262)

  • Subburaman Mohan

Long Beach VA Healthcare System (VA Merit Award BX004841)

  • Ling Gao

University of Arkansas for Medical Sciences (P20 GM 109005)

  • Nukhet Aykin-Burns

University of Arkansas for Medical Sciences (R24GM137786 and P20 GM121293)

  • Samuel G Mackintosh

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Ethics

Animal experimentation: All animal protocols and procedures used in animal studies were approved by the Institutional Animal Care and Use Committees of the University of Arkansas for Medical Sciences, Long Beach VA Healthcare System, and Loma Linda VA Healthcare System (IACUC #1685 and #1774). The protocols for generation and use of recombinant DNAs and retroviruses were approved by Institutional Biosafety Committee of Long Beach VA Healthcare System.832 (approval #1774).

Copyright

This is an open-access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.

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  1. Bhaba K Das
  2. Lei Wang
  3. Toshifumi Fujiwara
  4. Jian Zhou
  5. Nukhet Aykin-Burns
  6. Kimberly J Krager
  7. Renny Lan
  8. Samuel G Mackintosh
  9. Ricky Edmondson
  10. Michael L Jennings
  11. Xiaofang Wang
  12. Jian Q Feng
  13. Tomasa Barrientos
  14. Jyoti Gogoi
  15. Aarthi Kannan
  16. Ling Gao
  17. Weirong Xing
  18. Subburaman Mohan
  19. Haibo Zhao
(2022)
Transferrin receptor 1-mediated iron uptake regulates bone mass in mice via osteoclast mitochondria and cytoskeleton
eLife 11:e73539.
https://doi.org/10.7554/eLife.73539

Share this article

https://doi.org/10.7554/eLife.73539

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