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A Faster, High Resolution, mtPA-GFP-based Mitochondrial Fusion Assay Acquiring Kinetic Data of Multiple Cells in Parallel Using Confocal Microscopy
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Mitofusion is required for MOTS-c induced GLUT4 translocation

Khushwant S Bhullar1,2, Nan Shang1, Evan Kerek2

  • 1Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, AB, Canada.

Scientific Reports
|July 13, 2021
PubMed

Insights

Mitochondrial peptide MOTS-c enhances glucose uptake by promoting mitochondrial fusion, not just biogenesis. This discovery reveals a new pathway linking mitochondrial dynamics to metabolic improvements.

Area of Science:

  • Metabolic research
  • Mitochondrial biology
  • Molecular medicine

Background:

  • MOTS-c is a mitochondrial peptide known to improve insulin resistance and obesity.
  • The precise mechanisms underlying MOTS-c's pharmacological actions are not fully understood.
  • Previous studies suggest MOTS-c may influence mitochondrial function and cold adaptation.

Purpose of the Study:

  • To investigate the role of MOTS-c in mitochondrial biogenesis and dynamics.
  • To elucidate the molecular pathways connecting MOTS-c to improved glucose uptake.
  • To determine if mitochondrial fusion is involved in MOTS-c's metabolic effects.

Main Methods:

  • Treatment of mammalian cells with MOTS-c.
  • Assessed protein levels of mitochondrial biogenesis markers (TFAM, COX4, NRF1).
  • Flow cytometry with MitoTracker Green to quantify mitochondria.
  • Measured protein levels of mitochondrial fusion GTPases (OPA1, MFN2).
  • Inhibited GTPases using TNFα or siRNA to assess impact on GLUT4 translocation and glucose uptake.

Main Results:

  • MOTS-c increased markers of mitochondrial biogenesis but decreased overall mitochondrial count.
  • MOTS-c significantly upregulated OPA1 and MFN2, key proteins for mitochondrial fusion.
  • Inhibition of OPA1/MFN2 or MFN2 specifically blocked MOTS-c-induced GLUT4 translocation and glucose uptake.
  • This highlights a novel link between mitochondrial fusion and MOTS-c's metabolic benefits.

Conclusions:

  • MOTS-c promotes mitochondrial biogenesis and subsequent mitochondrial fusion.
  • Mitofusion is a critical step in MOTS-c's mechanism for enhancing glucose uptake.
  • This study reveals a new pathway linking mitochondrial dynamics to MOTS-c's therapeutic potential in metabolic disorders.

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