Document Type
Article
Publication Date
6-5-2026
Abstract
Mitochondria undergo fusion and fission. While DRP1 regulates fission, fusion is controlled by OPA1, MFN1, and MFN2. The balance between these processes and the crosstalk between machineries remains poorly understood. MFN2 mutations cause Charcot-Marie-Tooth disease type 2 A (CMT2A), affecting mitochondrial fusion and morphology. However, their role in fission is unclear. Using skin fibroblasts from CMT2A patients (L248H and M376V MFN2 mutations) and wild-type mouse embryonic fibroblasts expressing these variants, we studied how MFN2 mutations impact mitochondrial dynamics beyond fusion. We analyzed mitochondrial morphology and dynamics by live-cell confocal microscopy and tested fusion/fission protein levels, oxygen consumption rate (OCR), extracellular acidification rate (ECAR), and oxidative phosphorylation complex subunits. MFN2 mutations impaired mitochondrial fusion and displayed distinct effects on fission and cellular metabolism. L248H-expressing cells showed hyper-elongated mitochondria, impaired fission, and increased OCR, while M376V cells exhibited fragmentation, enhanced fission, and elevated ECAR. These effects correlated with differential Drp1 phosphorylation. Our findings demonstrate that MFN2 mutants differentially influence fission and metabolism, highlighting the need to consider these effects in therapies aimed at modulating mitochondrial dynamics.
Recommended Citation
Lagos, Daniel; de Santiago, Pamela R.; Pérez-Bravo, Nicolás; Cartes-Saavedra, Benjamín; Vial-Brizzi, Josefa; Troncoso-Chandía, Diego; Podmanicky, Oliver; Horvath, Rita; and Eisner, Verónica, "Disease-Causing MFN2 Mutants Impair Mitochondrial Fission Dynamics by Distinct DRP1 Dysregulation" (2026). Department of Pathology, Anatomy, and Cell Biology Faculty Papers. Paper 500.
https://jdc.jefferson.edu/pacbfp/500
Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 License.
PubMed ID
42248856
Language
English

Comments
This article is the author’s final published version in Cell Death and Disease, Volume 17, Issue 1, 2026, Article number 707.
The published version is available at https://doi.org/10.1038/s41419-026-08838-3. Copyright © The Author(s) 2026.