RRC ID 58399
Author Wakabayashi Y, Tamura Y, Kouzaki K, Kikuchi N, Hiranuma K, Menuki K, Tajima T, Yamanaka Y, Sakai A, Nakayama KI, Kawamoto T, Kitagawa K, Nakazato K.
Title Acetaldehyde dehydrogenase 2 deficiency increases mitochondrial reactive oxygen species emission and induces mitochondrial protease Omi/HtrA2 in skeletal muscle.
Journal Am J Physiol Regul Integr Comp Physiol
Abstract Acetaldehyde dehydrogenase 2 (ALDH2) is an enzyme involved in redox homeostasis as well as the detoxification process in alcohol metabolism. Nearly 8% of the world's population have an inactivating mutation in the ALDH2 gene. However, the expression patterns and specific functions of ALDH2 in skeletal muscles are still unclear. Herein, we report that ALDH2 is expressed in skeletal muscle and is localized to the mitochondrial fraction. Oxidative muscles had a higher amount of ALDH2 protein than glycolytic muscles. We next comprehensively investigated whether ALDH2 knockout in mice induces mitochondrial adaptations in gastrocnemius muscle (for example, content, enzymatic activity, respiratory function, supercomplex formation, and functional networking). We found that ALDH2 deficiency resulted in partial mitochondrial dysfunction in gastrocnemius muscle because it increased mitochondrial reactive oxygen species (ROS) emission (2',7'-dichlorofluorescein and MitoSOX oxidation rate during respiration) and the frequency of regional mitochondrial depolarization. Moreover, we determined whether ALDH2 deficiency and the related mitochondrial dysfunction trigger mitochondrial stress and quality control responses in gastrocnemius muscle (for example, mitophagy markers, dynamics, and the unfolded protein response). We found that ALDH2 deficiency upregulated the mitochondrial serine protease Omi/HtrA2 (a marker of the activation of a branch of the mitochondrial unfolded protein response). In summary, ALDH2 deficiency leads to greater mitochondrial ROS production, but homeostasis can be maintained via an appropriate stress response.
Volume 318(4)
Pages R677-R690
Published 2020-4-1
DOI 10.1152/ajpregu.00089.2019
PMID 32048867
MeSH Aldehyde Dehydrogenase, Mitochondrial / genetics Aldehyde Dehydrogenase, Mitochondrial / metabolism* Animals Gene Expression Regulation Genotype* High-Temperature Requirement A Serine Peptidase 2 / genetics High-Temperature Requirement A Serine Peptidase 2 / metabolism* Male Mice Mice, Inbred C57BL Mice, Knockout Mitochondria / metabolism* Muscle, Skeletal / metabolism* Oxygen Consumption Reactive Oxygen Species / metabolism*
IF 3.026
Times Cited 0
Mice RBRC05808