Burst mitofusin activation reverses neuromuscular dysfunction in murine CMT2A

  1. Antonietta Franco
  2. Xiawei Dang
  3. Emily K Walton
  4. Joshua N Ho
  5. Barbara Zablocka
  6. Cindy Ly
  7. Timothy M Miller
  8. Robert H Baloh
  9. Michael E Shy
  10. Andrew S Yoo
  11. Gerald W Dorn II  Is a corresponding author
  1. Washington University School of Medicine, United States
  2. Mossakowski Medical Research Centre, Poland
  3. Cedars-Sinai Medical Center, United States
  4. Carver College of Medicine, University of Iowa, United States

Abstract

Charcot-Marie-Tooth disease type 2A (CMT2A) is an untreatable childhood peripheral neuropathy caused by mutations of the mitochondrial fusion protein, mitofusin (MFN) 2. Here, pharmacological activation of endogenous normal mitofusins overcame dominant inhibitory effects of CMT2A mutants in reprogrammed human patient motor neurons, reversing hallmark mitochondrial stasis and fragmentation independent of causal MFN2 mutation. In mice expressing human MFN2 T105M, intermittent mitofusin activation with a small molecule, MiM111, normalized CMT2A neuromuscular dysfunction, reversed pre-treatment axon and skeletal myocyte atrophy, and enhanced axon regrowth by increasing mitochondrial transport within peripheral axons and promoting in vivo mitochondrial localization to neuromuscular junctional synapses. MiM111-treated MFN2 T105M mouse neurons exhibited accelerated primary outgrowth and greater post-axotomy regrowth, linked to enhanced mitochondrial motility. MiM111 is the first pre-clinical candidate for CMT2A.

Data availability

All data generated or analyzed during this study are included in the manuscript.

Article and author information

Author details

  1. Antonietta Franco

    Department of Internal Medicine, Pharmacogenomics, Washington University School of Medicine, St Louis, United States
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-5487-1800
  2. Xiawei Dang

    Department of Internal Medicine, Pharmacogenomics, Washington University School of Medicine, St Louis, United States
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-0343-7107
  3. Emily K Walton

    Department of Internal Medicine, Pharmacogenomics, Washington University School of Medicine, St Louis, United States
    Competing interests
    No competing interests declared.
  4. Joshua N Ho

    Department of Developmental Biology, Washington University School of Medicine, St Louis, United States
    Competing interests
    No competing interests declared.
  5. Barbara Zablocka

    Molecular Biology Unit, Mossakowski Medical Research Centre, Warsaw, Poland
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-2204-5184
  6. Cindy Ly

    Department of Neurology, Washington University School of Medicine, St Louis, United States
    Competing interests
    No competing interests declared.
  7. Timothy M Miller

    Department of Neurology, Washington University School of Medicine, St Louis, United States
    Competing interests
    No competing interests declared.
  8. Robert H Baloh

    Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, United States
    Competing interests
    No competing interests declared.
  9. Michael E Shy

    Department of Neurology, Carver College of Medicine, University of Iowa, Iowa City, United States
    Competing interests
    No competing interests declared.
  10. Andrew S Yoo

    Department of Developmental Biology, Washington University School of Medicine, St Louis, United States
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-0304-3247
  11. Gerald W Dorn II

    Department of Internal Medicine, Pharmacogenomics, Washington University School of Medicine, St Louis, United States
    For correspondence
    gdorn@wustl.edu
    Competing interests
    Gerald W Dorn II, G.W.D. is an inventor on patent applications PCT/US18/028514 submitted by Washington University and PCT/US19/46356 submitted by Mitochondria Emotion, Inc that cover the use of small molecule mitofusin agonists to treat chronic neurodegenerative diseases, and is a founder of Mitochondria in Motion, Inc., a Saint Louis based biotech R&D company focused on enhancing mitochondrial trafficking and fitness in neurodegenerative diseases..
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-8995-1624

Funding

NIH (R35HL135736)

  • Gerald W Dorn II

NIH (R41NS113642)

  • Gerald W Dorn II

NIH (R41NS115184)

  • Gerald W Dorn II

Muscular Dystrophy Association (628906)

  • Gerald W Dorn II

McDonnell Center for Cellular and Molecular (Neurobiology Postdoctoral Fellowship)

  • Antonietta Franco

Harrington Discovery Institute (Scholar-Innovator awardee)

  • Gerald W Dorn II

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 experimental procedures were approved by Washington University in St. Louis School of Medicine Animal Studies Committee; IACUC protocol number 19-0910, Exp:12/16/2022 (Gerald Dorn, PI).

Reviewing Editor

  1. Joseph G Gleeson, Howard Hughes Medical Institute, The Rockefeller University, United States

Version history

  1. Received: July 15, 2020
  2. Accepted: October 18, 2020
  3. Accepted Manuscript published: October 19, 2020 (version 1)
  4. Version of Record published: November 10, 2020 (version 2)

Copyright

© 2020, Franco et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

Metrics

  • 3,796
    Page views
  • 492
    Downloads
  • 30
    Citations

Article citation count generated by polling the highest count across the following sources: Crossref, PubMed Central, Scopus.

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. Antonietta Franco
  2. Xiawei Dang
  3. Emily K Walton
  4. Joshua N Ho
  5. Barbara Zablocka
  6. Cindy Ly
  7. Timothy M Miller
  8. Robert H Baloh
  9. Michael E Shy
  10. Andrew S Yoo
  11. Gerald W Dorn II
(2020)
Burst mitofusin activation reverses neuromuscular dysfunction in murine CMT2A
eLife 9:e61119.
https://doi.org/10.7554/eLife.61119

Share this article

https://doi.org/10.7554/eLife.61119

Further reading

    1. Cell Biology
    2. Plant Biology
    Maciek Adamowski, Ivana Matijević, Jiří Friml
    Research Article

    The GNOM (GN) Guanine nucleotide Exchange Factor for ARF small GTPases (ARF-GEF) is among the best studied trafficking regulators in plants, playing crucial and unique developmental roles in patterning and polarity. The current models place GN at the Golgi apparatus (GA), where it mediates secretion/recycling, and at the plasma membrane (PM) presumably contributing to clathrin-mediated endocytosis (CME). The mechanistic basis of the developmental function of GN, distinct from the other ARF-GEFs including its closest homologue GNOM-LIKE1 (GNL1), remains elusive. Insights from this study largely extend the current notions of GN function. We show that GN, but not GNL1, localizes to the cell periphery at long-lived structures distinct from clathrin-coated pits, while CME and secretion proceed normally in gn knockouts. The functional GN mutant variant GNfewerroots, absent from the GA, suggests that the cell periphery is the major site of GN action responsible for its developmental function. Following inhibition by Brefeldin A, GN, but not GNL1, relocates to the PM likely on exocytic vesicles, suggesting selective molecular associations en route to the cell periphery. A study of GN-GNL1 chimeric ARF-GEFs indicates that all GN domains contribute to the specific GN function in a partially redundant manner. Together, this study offers significant steps toward the elucidation of the mechanism underlying unique cellular and development functions of GNOM.

    1. Biochemistry and Chemical Biology
    2. Cell Biology
    Chenjie Xia, Huihui Xu ... Hongting Jin
    Research Article

    Glucocorticoid-induced osteonecrosis of the femoral head (GONFH) is a common refractory joint disease characterized by bone damage and the collapse of femoral head structure. However, the exact pathological mechanisms of GONFH remain unknown. Here, we observed abnormal osteogenesis and adipogenesis associated with decreased β-catenin in the necrotic femoral head of GONFH patients. In vivo and in vitro studies further revealed that glucocorticoid exposure disrupted osteogenic/adipogenic differentiation of bone marrow mesenchymal cells (BMSCs) by inhibiting β-catenin signaling in glucocorticoid-induced GONFH rats. Col2+ lineage largely contributes to BMSCs and was found an osteogenic commitment in the femoral head through 9 mo of lineage trace. Specific deletion of β-catenin gene (Ctnnb1) in Col2+ cells shifted their commitment from osteoblasts to adipocytes, leading to a full spectrum of disease phenotype of GONFH in adult mice. Overall, we uncover that β-catenin inhibition disrupting the homeostasis of osteogenic/adipogenic differentiation contributes to the development of GONFH and identify an ideal genetic-modified mouse model of GONFH.