Lebenzon 2022 Proc Natl Acad Sci U S A
| Lebenzon JE, Denezis PW, Mohammad L, Mathers KE, Turnbull KF, Staples JF, Sinclair BJ (2022) Reversible mitophagy drives metabolic suppression in diapausing beetles. Proc Natl Acad Sci U S A 119:e2201089119. https://doi.org/10.1073/pnas.2201089119 |
Lebenzon Jacqueline E, Denezis Peter W, Mohammad Lamees, Mathers Katherine E, Turnbull Kurtis F, Staples James F, Sinclair Brent J (2022) Proc Natl Acad Sci U S A
Abstract: Many insects enter a state of dormancy (diapause) during winter in which they lower their metabolism to save energy. Metabolic suppression is a hallmark of diapause, yet we know little about the mechanisms underpinning metabolic suppression in winter or how it is reversed in the spring. Here, we show that metabolic suppression in dormant Colorado potato beetles results from the breakdown of flight muscle mitochondria via mitophagy. Diapausing Colorado potato beetles suppress their metabolism by 90%, and this lowered metabolic rate coincides with a similar reduction in flight muscle mitochondrial function and density. During early diapause, beetles increase the expression of mitophagy-related transcripts (Parkin and ATG5) in their flight muscle coincident with an increase in mitophagy-related structures in the flight muscle. Knocking down Parkin expression with RNA interference in diapausing beetles prevented some mitochondrial breakdown and partially restored the whole animal metabolic rate, suggesting that metabolic suppression in diapausing beetles is driven by mitophagy. In other animals and in models of disease, such large-scale mitochondrial degradation is irreversible. However, we show that as diapause ends, beetles reverse mitophagy and increase the expression of PGC1Ξ± and NRF1 to replenish flight muscle mitochondrial pools. This mitochondrial biogenesis is activated in anticipation of diapause termination and in the absence of external stimuli. Our study provides a mechanistic link between mitochondrial degradation in insect tissues over the winter and whole-animal metabolic suppression. β’ Keywords: Dormancy, Insect flight muscle, Mitochondria, Mitophagy β’ Bioblast editor: Plangger M β’ O2k-Network Lab: CA London Staples JF
Labels: MiParea: Respiration, Comparative MiP;environmental MiP
Organism: Hexapods
Tissue;cell: Skeletal muscle
Preparation: Permeabilized tissue
Coupling state: LEAK, OXPHOS, ET
Pathway: N
HRR: Oxygraph-2k
2024-04
