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Background: Skeletal muscle mitochondrial content and function appear to be altered in obesity. Mitochondria in muscle are found in well-defined regions within cells, and they are arranged in a way that form distinct subpopulations of subsarcolemmal (SS) and intermyofibrillar (IMF) mitochondria. We sought to investigate differences in the proteomes of SS and IMF mitochondria between lean subjects and subjects with obesity.
Methods: We performed comparative proteomic analyses on SS and IMF mitochondria isolated from muscle samples obtained from lean subjects and subjects with obesity. Mitochondria were isolated using differential centrifugation, and proteins were subjected to label-free quantitative tandem mass spectrometry analyses. Collected data were evaluated for abundance of mitochondrial proteins using spectral counting. The Reactome pathway database was used to determine metabolic pathways that are altered in obesity.
Results: Among proteins, 73 and 41 proteins showed different (mostly lower) expression in subjects with obesity in the SS and IMF mitochondria, respectively (false discovery rate-adjusted P ≤ 0.05). We specifically found an increase in proteins forming the tricarboxylic acid cycle and electron transport chain (ETC) complex II, but a decrease in proteins forming protein complexes I and III of the ETC and adenosine triphosphate (ATP) synthase in subjects with obesity in the IMF, but not SS, mitochondria. Obesity was associated with differential effects on metabolic pathways linked to protein translation in the SS mitochondria and ATP formation in the IMF mitochondria.
Conclusions: Obesity alters the expression of mitochondrial proteins regulating key metabolic processes in skeletal muscle, and these effects are distinct to mitochondrial subpopulations located in different regions of the muscle fibers.
Trial Registration: ClinicalTrials.gov (NCT01824173).
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http://dx.doi.org/10.1016/j.metabol.2018.09.006 | DOI Listing |
Biochem Biophys Res Commun
May 2025
Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China. Electronic address:
Intramuscular fat (IMF) is a key determinant of meat quality in pigs, influencing characteristics such as tenderness, flavor, and marbling. The regulation of IMF deposition involves complex metabolic processes, with mitochondrial function playing a central role. PTEN-induced kinase 1 (PINK1), a protein involved in mitophagy and mitochondrial quality control, has recently been implicated in regulating fat deposition, although its role in IMF deposition in pigs remains unclear.
View Article and Find Full Text PDFAm J Physiol Cell Physiol
September 2024
Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, South Carolina, United States.
Cancer cachexia, the unintentional loss of lean mass, contributes to functional dependency, poor treatment outcomes, and decreased survival. Although its pathogenicity is multifactorial, metabolic dysfunction remains a hallmark of cachexia. However, significant knowledge gaps exist in understanding the role of skeletal muscle lipid metabolism and dynamics in this condition.
View Article and Find Full Text PDFJ Neuroinflammation
January 2024
Department of Functional Anatomy and Neuroscience, Nagoya University Graduate School of Medicine, 65 Tsurumaicho, Showa-Ku, Nagoya, Aichi, 466-8550, Japan.
Background: Fibromyalgia is characterized by chronic pain, fatigue, and other somatic symptoms. We have recently revealed that proprioceptor hyperactivation induces chronic pain in a rat model of myalgic encephalomyelitis. The present study explores whether similar proprioceptor-induced pain is elicited in a mouse model of fibromyalgia.
View Article and Find Full Text PDFAnimals (Basel)
January 2024
College of Animal Science, Anhui Science and Technology University, Chuzhou 239000, China.
Wannanhua (WH) is a pig breed indigenous to Anhui Province, China. This breed has a high intramuscular fat (IMF) content, making it an ideal model for investigating lipid deposition mechanisms in pigs. IMF content is one of the main indicators of meat quality in pigs and is regulated by multiple genes and metabolic pathways.
View Article and Find Full Text PDFJ Cachexia Sarcopenia Muscle
February 2024
Longitudinal Studies Section, Translational Gerontology Branch, National Institute on Aging, Baltimore, MD, USA.
Background: Mitochondrial dysfunction may contribute to brain and muscle health through inflammation or fat infiltration in the muscle, both of which are associated with cognitive function and mobility. We aimed to examine the association between skeletal muscle mitochondrial function and cognitive and mobility outcomes and tested the mediation effect of inflammation or fat infiltration.
Methods: We analysed data from 596 Baltimore Longitudinal Study of Aging participants who had concurrent data on skeletal muscle oxidative capacity and cognitive and mobility measures of interest (mean age: 66.