bims-mitpro 2025-11-16 papers

Issue of 2025–11–16
two papers selected by
Andreas Kohler, Umeå University

Front Cell Dev Biol. 2025 ;13 1652353

UPRmt-regulated mitokines: novel strategies for myocardial injury repair.

Weinan Gao, Jia Liu, Wenda Zhang, Bin Liu, Luyan Shen.

Cardiac mitochondria generate ATP, via oxidative phosphorylation (OXPHOS) to sustain continuous and forceful myocardial contraction, thereby meeting systemic metabolic demands. Mitochondrial biogenesis and energy metabolism depend on proteostasis, which can be disrupted by stressors such as hypoxia, leading to impaired cardiac function. As a result, the study of mitochondrial energy metabolism and proteostasis under stress has become a key focus in cardiovascular research. The mitochondrial unfolded protein response (UPRmt) plays a "double-edged sword" role-either protective or detrimental-depending on the type, intensity, and duration of the stressor. This has sparked interest in strategies aimed at enhancing its adaptive signaling while inhibiting maladaptive pathways. Acting as mediators of intercellular communication, mitokines may transmit local mitochondrial stress signals to mitochondria in distant cells and tissues. This review analyzes and summarizes the role of UPRmt in regulating mitochondrial factors and explores the mechanisms through which fibroblast growth factor 21 (FGF21), secreted by the liver and skeletal muscle, influences protein homeostasis in cardiac myocytes. These insights aim to offer new avenues for the development of targeted UPRmt therapies and rehabilitation strategies for heart diseases.

Keywords: cardiac diseases; fibroblast growth factor 21 (FGF21); mitochondrial stress; mitochondrial unfolded protein response (UPRmt); mitokines

DOI: https://doi.org/10.3389/fcell.2025.1652353

Autophagy. 2025 Nov 10.

Piecemeal mitochondrial degradation in plants: a coordination between mitochondrial dynamics and mitophagosome formation.

Juncai Ma, Chaorui Li, Xiaohong Zhuang.

Mitochondrial dynamics play critical roles in mitochondrial quality control to maintain mitochondrial function. In plants, mitochondria are typically discrete rather than networked, but how damaged mitochondrial contents can be efficiently removed remains unclear. In a recent study, we demonstrate that the plant-specific fission regulator ELM1, together with DRP3 and the autophagic adaptor SH3P2, orchestrates mitochondrial dynamics and mitophagosome assembly for piecemeal mitophagy under heat stress condition. Deficiency in mitochondrial fission activity delays mitophagosome formation and leads to an accumulation of megamitochondria that are partially sequestered by phagophore intermediates positive for ATG8 and NBR1. Further 3D electron tomography analysis reveals that phagophore fragments expand toward the constriction sites of the abnormal protrusions from the mitochondrial body. These findings highlight an unappreciated role of plant mitochondrial fission machinery in coupling with autophagy machinery for mitochondrial segregation and mitophagosome assembly, establishing a mechanistic framework for plant mitophagy in stress resilience.

Keywords: ELM1; SH3P2; mitochondrial dynamics; mitochondrial fission; piecemeal mitophagy

DOI: https://doi.org/10.1080/15548627.2025.2587051