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.

Metrics

  • 2,333
    views
  • 623
    downloads
  • 35
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  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

Further reading

    1. Cell Biology
    Tamás Visnovitz, Dorina Lenzinger ... Edit I Buzas
    Short Report

    Recent studies showed an unexpected complexity of extracellular vesicle (EV) biogenesis pathways. We previously found evidence that human colorectal cancer cells in vivo release large multivesicular body-like structures en bloc. Here, we tested whether this large EV type is unique to colorectal cancer cells. We found that all cell types we studied (including different cell lines and cells in their original tissue environment) released multivesicular large EVs (MV-lEVs). We also demonstrated that upon spontaneous rupture of the limiting membrane of the MV-lEVs, their intraluminal vesicles (ILVs) escaped to the extracellular environment by a ‘torn bag mechanism’. We proved that the MV-lEVs were released by ectocytosis of amphisomes (hence, we termed them amphiectosomes). Both ILVs of amphiectosomes and small EVs separated from conditioned media were either exclusively CD63 or LC3B positive. According to our model, upon fusion of multivesicular bodies with autophagosomes, fragments of the autophagosomal inner membrane curl up to form LC3B positive ILVs of amphisomes, while CD63 positive small EVs are of multivesicular body origin. Our data suggest a novel common release mechanism for small EVs, distinct from the exocytosis of multivesicular bodies or amphisomes, as well as the small ectosome release pathway.

    1. Cell Biology
    2. Genetics and Genomics
    Adam D Longhurst, Kyle Wang ... David P Toczyski
    Tools and Resources

    Progression through the G1 phase of the cell cycle is the most highly regulated step in cellular division. We employed a chemogenetic approach to discover novel cellular networks that regulate cell cycle progression. This approach uncovered functional clusters of genes that altered sensitivity of cells to inhibitors of the G1/S transition. Mutation of components of the Polycomb Repressor Complex 2 rescued proliferation inhibition caused by the CDK4/6 inhibitor palbociclib, but not to inhibitors of S phase or mitosis. In addition to its core catalytic subunits, mutation of the PRC2.1 accessory protein MTF2, but not the PRC2.2 protein JARID2, rendered cells resistant to palbociclib treatment. We found that PRC2.1 (MTF2), but not PRC2.2 (JARID2), was critical for promoting H3K27me3 deposition at CpG islands genome-wide and in promoters. This included the CpG islands in the promoter of the CDK4/6 cyclins CCND1 and CCND2, and loss of MTF2 lead to upregulation of both CCND1 and CCND2. Our results demonstrate a role for PRC2.1, but not PRC2.2, in antagonizing G1 progression in a diversity of cell linages, including chronic myeloid leukemia (CML), breast cancer, and immortalized cell lines.