Perturbation of Human Coronary Artery Endothelial Cell Redox State and NADPH Generation by Methylglyoxal

Morgan, Philip E.; Sheahan, Pamela J.; Davies, Michael J.
January 2014
PLoS ONE;Jan2014, Vol. 9 Issue 1, p1
Academic Journal
Diabetes is associated with elevated plasma glucose, increased reactive aldehyde formation, oxidative damage, and glycation/glycoxidation of biomolecules. Cellular detoxification of, or protection against, such modifications commonly requires NADPH-dependent reducing equivalents (e.g. GSH). We hypothesised that reactive aldehydes may modulate cellular redox status via the inhibition of NADPH-generating enzymes, resulting in decreased thiol and NADPH levels. Primary human coronary artery endothelial cells (HCAEC) were incubated with high glucose (25 mM, 24 h, 37°C), or methylglyoxal (MGO), glyoxal, or glycolaldehyde (100–500 µM, 1 h, 37°C), before quantification of intracellular thiols and NADPH-generating enzyme activities. Exposure to MGO, but not the other species examined, significantly (P<0.05) decreased total thiols (∼35%), further experiments with MGO showed significant losses of GSH (∼40%) and NADPH (∼10%); these changes did not result in an immediate loss of cell viability. Significantly decreased (∼10%) NADPH-producing enzyme activity was observed for HCAEC when glucose-6-phosphate or 2-deoxyglucose-6-phosphate were used as substrates. Cell lysate experiments showed significant MGO-dose dependent inhibition of glucose-6-phosphate-dependent enzymes and isocitrate dehydrogenase, but not malic enzyme. Analysis of intact cell or lysate proteins showed that arginine-derived hydroimidazolones were the predominant advanced glycation end-product (AGE) formed; lower levels of Nε-(carboxyethyl)lysine (CEL) and Nε-(carboxymethyl)lysine (CML) were also detected. These data support a novel mechanism by which MGO exposure results in changes in redox status in human coronary artery endothelial cells, via inhibition of NADPH-generating enzymes, with resultant changes in reduced protein thiol and GSH levels. These changes may contribute to the endothelial cell dysfunction observed in diabetes-associated atherosclerosis.


Related Articles

  • Structure of catalytically competent intein caught in a redox trap with functional and evolutionary implications. Callahan, Brian P.; Topilina, Natalya I.; Stanger, Matthew J.; Van Roey, Patrick; Belfort, Marlene // Nature Structural & Molecular Biology;May2011, Vol. 18 Issue 5, p630 

    Here we describe self-splicing proteins, called inteins, that function as redox-responsive switches in bacteria. Redox regulation was achieved by engineering a disulfide bond between the intein's catalytic cysteine and a cysteine in the flanking 'extein' sequence. This interaction was validated...

  • Diagram techniques for solving Schwinger–Dyson equations: Electron transfer pathways in biological molecules. Magarshak, Y.; Malinsky, J.; Joran, A. D. // Journal of Chemical Physics;7/1/1991, Vol. 95 Issue 1, p418 

    A graph method is developed to solve Schwinger–Dyson equations for electron transfer reactions in biological molecules. Feynman diagrams provide a convenient technique for the calculation of self-energy. Multiple pathway mechanisms of electron transfer can be examined by splitting of the...

  • Bioinformatic evidence for a widely distributed, ribosomally produced electron carrier precursor, its maturation proteins, and its nicotinoprotein redox partners. Haft, Daniel H. // BMC Genomics;2011, Vol. 12 Issue 1, p1 

    Background: Enzymes in the radical SAM (rSAM) domain family serve in a wide variety of biological processes, including RNA modification, enzyme activation, bacteriocin core peptide maturation, and cofactor biosynthesis. Evolutionary pressures and relationships to other cellular constituents...

  • Study of Electrochromic Behaviour of bis octakis(octyl)phthalocyaninato lutetium(III) and Detection of Biomolecules in situ. Pal, C.; Ray, A. K.; Withnall, R. // AIP Conference Proceedings;8/6/2010, Vol. 1267 Issue 1, p611 

    The article presents a study on the electrochromic behaviour of bis octakis (octyl) phthalocyaninato lutetium (III) and detection of biomolecules in situ. It aims at utilizing the redox property of substituted R16Lu(Pc)2 (R=C8H17) for the detection of nicotinamide-adenine dinucleotide hydrate...

  • Methemoglobinemia–A biomarker and a link to ferric iron accumulation in Alzheimer's disease. Mohorovic, Lucijan; Lavezzi, Anna M.; Stifter, Sanja; Perry, George; Malatestinic, Djulija; Micovic, Vladimir; Materljan, Eris; Haller, Herman; Petrovic, Oleg // Advances in Bioscience & Biotechnology;Jan2014, Vol. 5 Issue 1, p12 

    Understanding the mechanism of oxidative stress is likely to yield new insights regarding the pathogenesis of Alzheimer's disease (AD). Our earlier work focused on the difference between hemoglobin and methemoglobin degradation, respectively leading to ferrous (Fe2+) iron, or ferric (Fe3+) iron....

  • Hyperoxidized peroxiredoxin 2 interacts with the protein disulfideisomerase ERp46. PACE, Paul E.; PESKIN, Alexander V.; HAN, Min-Hi; HAMPTON, Mark B.; WINTERBOURN, Christine C. // Biochemical Journal;8/1/2013, Vol. 453 Issue 3, p475 

    Prx (peroxiredoxin) 2 protects cells from deleterious oxidative damage. It catalyses the breakdown of hydroperoxides through a highly reactive cysteine residue and has been linked to chaperone activity that promotes cell survival under conditions of oxidative stress. It may also be involved in...

  • ROS signaling and redox biology in endothelial cells. Panieri, Emiliano; Santoro, Massimo // Cellular & Molecular Life Sciences;Sep2015, Vol. 72 Issue 17, p3281 

    The purpose of this review is to provide an overview of redox mechanisms, sources and antioxidants that control signaling events in ECs. In particular, we describe which molecules are involved in redox signaling and how they influence the relationship between ECs and other vascular component...

  • Circulating MACC1 Transcripts in Colorectal Cancer Patient Plasma Predict Metastasis and Prognosis. Stein, Ulrike; Burock, Susen; Herrmann, Pia; Wendler, Ina; Niederstrasser, Markus; Wernecke, Klaus-Dieter; Schlag, Peter M. // PLoS ONE;Nov2012, Vol. 7 Issue 11, Special section p1 

    Background: Metastasis is the most frequent cause of treatment failure and death in colorectal cancer. Early detection of tumors and metastases is crucial for improving treatment strategies and patient outcome. Development of reliable biomarkers and simple tests routinely applicable in the...

  • Imbalance between Pro and Anti-Oxidant Mechanisms in Perivascular Adipose Tissue Aggravates Long-Term High-Fat Diet-Derived Endothelial Dysfunction. Gil-Ortega, Marta; Condezo-Hoyos, Luis; García-Prieto, Concha F.; Arribas, Silvia M.; González, M. Carmen; Aranguez, Isabel; Ruiz-Gayo, Mariano; Somoza, Beatriz; Fernández-Alfonso, María S. // PLoS ONE;Apr2014, Vol. 9 Issue 4, p1 

    Background: The hypothesis of this study is that long-term high-fat diets (HFD) induce perivascular adipose tissue (PVAT) dysfunction characterized by a redox imbalance, which might contribute to aggravate endothelial dysfunction in obesity. Methods and Results: C57BL/6J mice were fed either...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics