Disruption of Mitochondrial Dynamics and Integrity Drives Divergent Metabolic Flexibility and Resilience in Podocytes

Cem Özel, Katrin M. Reitmeier, Emilia Kieckhöfer, Khawla Abualia, Duc Nguyen‐Minh, Mahsa Matin, Henning Hagmann, Richard J. M. Coward, Sebastian Brähler, Philipp Antczak, Bernhard Schermer, Thomas Benzing, Patrick Giavalisco, Paul T. Brinkkoetter*

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)peer-review

Abstract

Mitochondrial dysfunction is central to the pathogenesis of podocytopathies, yet the determinants of metabolic resilience versus failure remain elusive. We investigated how distinct disruptions of mitochondrial architecture, specifically hyperfusion via OMA1 deletion versus compromised inner mitochondrial membrane (IMM) integrity via PHB2 knockdown, influence the metabolic fate and insulin responsiveness of podocytes. To this end, we analyzed conditionally immortalized mouse podocytes with genetic OMA1 deletion or inducible PHB2 knockdown and employed an integrated approach combining bioenergetic studies, quantitative proteomics, phosphoproteomics, metabolomics, and stable isotope tracing studies with 13C6‐glucose and 13C5‐glutamine. We characterized metabolic remodeling at baseline and after insulin treatment and uncovered profoundly divergent metabolic states. OMA1 deficiency conferred robust metabolic resilience, characterized by a compensatory glycolytic shift and remodeling of TCA cycle flux through glutamine‐driven anaplerosis while maintaining oxidative phosphorylation. OMA1‐deficient podocytes sustained bioenergetic homeostasis upon insulin challenge by flexibly rerouting carbon flux, including the GABA shunt. In contrast, PHB2 deficiency led to metabolic failure, impaired respiration, and anaplerotic insufficiency. While maintaining basal ATP levels at baseline, PHB2‐deficient podocytes exhibited energetic collapse upon insulin treatment, revealing profound metabolic inflexibility. Taken together, the structural integrity of the inner mitochondrial membrane, rather than mitochondrial morphology per se, is a driving determinant of metabolic competence and resilience in podocytes.
Original languageEnglish
Article numbere71340
Number of pages18
JournalFASEB Journal
Volume39
Issue number24
Early online date13 Dec 2025
DOIs
Publication statusPublished - 31 Dec 2025

Bibliographical note

Publisher Copyright:
© 2025 The Author(s). The FASEB Journal published by Wiley Periodicals LLC on behalf of Federation of American Societies for Experimental Biology.

Keywords

  • PHB2
  • mitochondria
  • OMA1
  • podocytes
  • insulin signaling
  • anaplerosis
  • glycolysis
  • metabolism

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