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Slavin MB, Memme JM, Oliveira AN, Moradi N, Hood DA. Regulatory networks controlling mitochondrial quality control in skeletal muscle. Am J Physiol Cell Physiol 2022; 322:C913-C926. [PMID: 35353634 DOI: 10.1152/ajpcell.00065.2022] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The adaptive plasticity of mitochondria within skeletal muscle is regulated by signals converging on a myriad of regulatory networks that operate during conditions of increased (i.e. exercise) and decreased (inactivity, disuse) energy requirements. Notably, some of the initial signals that induce adaptive responses are common to both conditions, differing in their magnitude and temporal pattern, to produce vastly opposing mitochondrial phenotypes. In response to exercise, signaling to PGC-1α and other regulators ultimately produces an abundance of high quality mitochondria, leading to reduced mitophagy and a higher mitochondrial content. This is accompanied by the presence of an enhanced protein quality control system that consists of the protein import machinery as well chaperones and proteases termed the UPRmt. The UPRmt monitors intra-organelle proteostasis, and strives to maintain a mito-nuclear balance between nuclear- and mtDNA-derived gene products via retrograde signaling from the organelle to the nucleus. In addition, antioxidant capacity is improved, affording greater protection against oxidative stress. In contrast, chronic disuse conditions produce similar signaling but result in decrements in mitochondrial quality and content. Thus, the interactive cross-talk of the regulatory networks that control organelle turnover during wide variations in muscle use and disuse remain incompletely understood, despite our improving knowledge of the traditional regulators of organelle content and function. This brief review acknowledges existing regulatory networks and summarizes recent discoveries of novel biological pathways involved in determining organelle biogenesis, dynamics, mitophagy, protein quality control and antioxidant capacity, identifying ample protein targets for therapeutic intervention that determine muscle and mitochondrial health.
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Affiliation(s)
- Mikhaela B Slavin
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada.,School of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | - Jonathan M Memme
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada.,School of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | - Ashley N Oliveira
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada.,School of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | - Neushaw Moradi
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada.,School of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | - David A Hood
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada.,School of Kinesiology and Health Science, York University, Toronto, ON, Canada
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