Unveiling the ‘Red Queen’s’ Rule: Microtubule Dynamics Governing Mitophagy Deficiency in Burn-Induced Stress

Introduction:
Mitophagy, the autophagic degradation of mitochondria, is a conserved quality control system critical for cellular health. Dysregulation of mitophagy contributes to various human diseases, yet the role of microtubule (MT) network defects in this process remains unclear. Drawing inspiration from Lewis Carroll’s Red Queen’s race, a metaphor for the relentless pursuit of equilibrium, we explore its application to cytoskeleton network dynamics and its impact on mitophagy regulation. This study reveals, for the first time, the governing role of the Red Queen’s race in the formation of microtubule networks and its consequential defect in mitophagy response under stress conditions.
Materials and Methods:
To assess MT network formation, MT synthesis speed, and mitophagy flux, C2C12 myocyte cell lines expressing mRuby-tubulin, GFP-EB1 (a microtubule plus end TIP marker), and mito-Keima were established. Burn-induced stress models were created using rat-derived serum covering 30% of the body surface. MT synthesis speed, network formation, and mitophagosome maturation were monitored under both burn and control serum conditions using live-cell imaging techniques.
Results:
In burn serum conditions, the synthesis speed of MTs, as monitored by EB1 motion, significantly decreased compared to controls. While basal MT network formation showed no differences between burn and control groups, mitophagy stimulation with CCCP revealed a marked deficiency in MTs in the burn group. Mito-Keima analysis indicated defective autophagosome/mitophagosome/lysosome vesicle trafficking and poor mitophagosome maturation after induction in the burn group.
Discussion:
This groundbreaking study highlights the abnormality of MTs under conditions demanding their upregulation for synthesis, emphasizing the importance of matching supply with demand. The Red Queen’s race analogy aptly describes the necessity for vigorous MT synthesis to maintain proper structure, especially under conditions requiring upregulated mitophagy flux. The observed defect in the Red Queen race in burns results in poor vesicle trafficking, contributing to inadequate mitophagosome maturation. This novel insight provides a foundation for understanding the intricate interplay between cytoskeletal dynamics and mitophagy regulation in pathological conditions.