Mitochondrial stress causes increased succination of proteins in adipocytes in response to glucotoxicity.

Biochem J

Department of Pharmacology, Physiology and Neuroscience, School of Medicine, University of South Carolina, Columbia, SC 29208, USA.

Published: July 2012

2SC [S-(2-succino)-cysteine] is a chemical modification formed by a Michael addition reaction of fumarate with cysteine residues in proteins. Formation of 2SC, termed 'succination' of proteins, increases in adipocytes grown in high-glucose medium and in adipose tissues of Type 2 diabetic mice. However, the metabolic mechanisms leading to increased fumarate and succination of protein in the adipocyte are unknown. Treatment of 3T3 cells with high glucose (30 mM compared with 5 mM) caused a significant increase in cellular ATP/ADP, NADH/NAD+ and Δψm (mitochondrial membrane potential). There was also a significant increase in the cellular fumarate concentration and succination of proteins, which may be attributed to the increase in NADH/NAD+ and subsequent inhibition of tricarboxylic acid cycle NAD+-dependent dehydrogenases. Chemical uncouplers, which dissipated Δψm and reduced the NADH/NAD+ ratio, also decreased the fumarate concentration and protein succination. High glucose plus metformin, an inhibitor of complex I in the electron transport chain, caused an increase in fumarate and succination of protein. Thus excess fuel supply (glucotoxicity) appears to create a pseudohypoxic environment (high NADH/NAD+ without hypoxia), which drives the increase in succination of protein. We propose that increased succination of proteins is an early marker of glucotoxicity and mitochondrial stress in adipose tissue in diabetes.

Download full-text PDF

Source
http://dx.doi.org/10.1042/BJ20112142DOI Listing

Publication Analysis

Top Keywords

succination proteins
12
succination protein
12
mitochondrial stress
8
increased succination
8
fumarate succination
8
high glucose
8
caused increase
8
increase cellular
8
fumarate concentration
8
succination
7

Similar Publications

Protein S-palmitoylation is the process by which a palmitoyl fatty acid is attached to a cysteine residue of a protein via a thioester bond. A range of methodologies are available for the detection of protein S-palmitoylation. In this study, two methods for the S-palmitoylation of different proteins were compared after metabolic labeling of cells with 15-hexadecynoic acid (15-YNE) to ascertain their relative usefulness.

View Article and Find Full Text PDF

Acute Severe Hypoxia Decreases Mitochondrial Chain Complex II Respiration in Human Peripheral Blood Mononuclear Cells.

Int J Mol Sci

January 2025

Biomedicine Research Center of Strasbourg (CRBS), UR 3072, "Mitochondria, Oxidative Stress and Muscle Plasticity", Faculty of Medicine, University of Strasbourg, 67000 Strasbourg, France.

Peripheral blood mononuclear cells' (PBMCs) mitochondrial respiration is impaired and likely involved in myocardial injury and heart failure pathophysiology, but its response to acute and severe hypoxia, often associated with such diseases, is largely unknown in humans. We therefore determined the effects of acute hypoxia on PBMC mitochondrial respiration and ROS production in healthy volunteers exposed to controlled oxygen reduction, achieving an inspired oxygen fraction of 10.5%.

View Article and Find Full Text PDF

Post-translational modifications of proteins via palmitoylation, a thioester linkage of a 16-carbon fatty acid to a cysteine residue, reversibly increases their affinity for cholesterol-rich lipid rafts in membranes, changing their function. Little is known about how altered palmitoylation affects function at the systemic level and contributes to CNS pathology. However, recent studies suggested a role for the downregulation of palmitoyl acetyltransferase (DHHC) 21 gene expression in the development of Major Depressive Disorder (MDD)-like syndrome.

View Article and Find Full Text PDF

Deciphering the impact of NOS-derived NO on nitrogen metabolism and carbon flux in the heterocytous cyanobacterium Aphanizomenon flos-aquae 2012/KM1/D3.

Plant Physiol Biochem

January 2025

Laboratory of Microbial Genetics, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi, 221005, India. Electronic address:

Nitric oxide synthases (NOSs) are heme-based monooxygenases that catalyze the NADPH-dependent oxidation of L-arginine to produce NO and L-citrulline. Over the past five years, the identification and characterization of NOS homologs in cyanobacteria have significantly advanced our understanding of these enzymes. However, the precise mechanisms through which NOS-derived NO influences nitrogen metabolism remain incompletely elucidated.

View Article and Find Full Text PDF

Introduction: The gut microbiota plays a pivotal role in influencing host health, through the production of metabolites and other key signalling molecules. While the impact of specific metabolites or taxa on host cells is well-documented, the broader impact of a disrupted microbiota on immune homeostasis is less understood, which is particularly important in the context of the increasing overuse of antibiotics.

Methods: Female C57BL/6 mice were gavaged twice daily for four weeks with Vancomycin, Polymyxin B, or PBS (control).

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!