Electric field stimulation revealed age-related mitochondrial Ca2+ overload in C. elegans muscle, reduced by mitoxantrone via MCU inhibition, enabling repeated in vivo assessment.
Electric field stimulation provides a robust in vivo method to probe mitochondrial calcium dynamics in C. elegans, revealing age-related calcium overload that can be attenuated by MCU inhibition.
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• 10 V/10 s electric pulses evoke Ca 2+ mito transients in C. elegans pharynx. • Electric pulses yield more consistent Ca 2+ mito readouts than caffeine. • Basal and stimulated Ca 2+ mito increase with age, revealing overload risk. • Mitoxantrone reduces age-related Ca 2+ mito overload during repeated stimulation. • Corpus shows stronger MCU-sensitive Ca 2+ mito uptake/overload than posterior bulb. Mitochondrial calcium (Ca 2+ mito ) homeostasis is a key regulator of cellular physiology, controlling signal transduction, energy metabolism, and cell survival. To examine how these processes change with age in vivo , we used the pharyngeal muscle of Caenorhabditis elegans (C. elegans) as a tractable model for studying Ca 2+ mito dynamics. We introduced electric field stimulation as a robust trigger for Ca 2+ mito uptake that overcomes limitations of compound stimulation, which relies on pharyngeal pumping and endoplasmic reticulum store filling and is typically confined to single-stimulus protocols. In contrast, electric field stimulation enables physiologically relevant repeated excitation that challenges Ca 2+ mito uptake and recovery. Stimulation with 10 V for 10 s reliably evoked reproducible Ca 2+ mito transients in the pharyngeal muscle of C. elegans and produced higher responder rates than compound stimulation. Basal Ca 2+ mito increased with age, and the first field-evoked transient was significantly larger in aged animals, an effect not detected with pharmacological triggers. Repeated pulses unmasked cumulative Ca 2+ mito loading and incomplete recovery in aged pharynx, indicative of Ca 2+ mito overload, which was attenuated by inhibition of the mitochondrial Ca 2+ uniporter (MCU) with mitoxantrone. Regional analyses identified the corpus as a hotspot for electric field-evoked Ca 2+ mito uptake and overload, while MCU inhibition reduced repeated responses in both corpus and posterior bulb. Electric field stimulation enables precise, repeated in vivo probing of Ca 2+ mito uptake and recovery, revealing overload in the C. elegans pharynx. This approach identified age-enhanced, MCU-dependent, and region-specific Ca 2+ mito loading, providing a pathophysiologically relevant readout of impaired Ca 2+ handling that may contribute to age-related muscle dysfunction.
Gabrijelčič et al. (Sun,) reported a other. Electric field stimulation revealed age-related mitochondrial Ca2+ overload in C. elegans muscle, reduced by mitoxantrone via MCU inhibition, enabling repeated in vivo assessment.