Determination of glyoxal and methylglyoxal in the serum of diabetic patients by MEKC using stilbenediamine as derivatizing reagent

Mirza, Muhammad Aslam; Kandhro, Abdul Jabbar; Memon, Saima Q.; Khuhawar, Muhammad Yar; Arain, Rafee

doi:10.1002/elps.200700129

Cited by 36 publications

(28 citation statements)

References 25 publications

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“…However, it is not clear how MG moves across cellular membranes (29). The plasma MG level is 2 μM in diabetic patients, whereas it is approximately 0.6 μM in nondiabetic subjects (30,31). Although MG concentrations used in our experiments were much higher than the plasma MG level, it is possible that MG incorporated into cells acts at physiologically relevant levels.…”

Section: Discussionmentioning

confidence: 77%

Methylglyoxal Causes Dysfunction of Thioredoxin and Thioredoxin Reductase in Endothelial Cells

et al. 2009

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Abstract. Methylglyoxal (MG), a reactive dicarbonyl produced during glucose metabolism, induces oxidative stress and apoptosis. Under hyperglycemic conditions, the abnormal accumulation of MG is related to the development of diabetic complications. We examined the effects of MG on thioredoxin (Trx) and glutaredoxin (Grx) systems, two thiol-disulfide oxidoreductase systems that protect against oxidative damage of proteins, in bovine aortic endothelial cells (BAECs). The levels of protein carbonyls as markers of protein oxidation increased in BAECs exposed to MG at 5 mM, resulting in the loss of cell viability. Western blot analysis demonstrated that Trx protein level decreased when BAECs were exposed to 5 mM MG. MG also inactivated Trx reductase, which maintains Trx in the reduced/active state. Moreover, peroxiredoxin, which is dependent on Trx and Trx reductase to maintain its reduced state, was oxidized by 5 mM MG. No significant difference in the levels of Trx, Trx reductase, or peroxiredoxin was observed in BAECs exposed to MG at 1 mM; this concentration had little effect on protein carbonyl formation and cell viability. MG failed to decrease Grx activity, indicating that Trx is more susceptible to MG than Grx. Taken together, these findings suggest that MG causes dysfunction of the Trx system, including Trx and Trx reductase, in BAECs.

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Section: Discussionmentioning

confidence: 77%

Methylglyoxal Causes Dysfunction of Thioredoxin and Thioredoxin Reductase in Endothelial Cells

et al. 2009

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“…Two experimental limitations should be discussed. First, the MG concentration present in the culture medium is much higher than that found in diabetic patient plasma (31,35). However, it must be indicated that clinical situations are much more complicated, and actual MG concentrations to which in vivo cells are exposed remain uncertain.…”

Section: Discussionmentioning

confidence: 99%

Methylglyoxal increases cardiomyocyte ischemia-reperfusion injury via glycative inhibition of thioredoxin activity

Wang

Lau

Yuan

et al. 2010

American Journal of Physiology-Endocrinology and Metabolism

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Diabetes mellitus (DM) is closely related to cardiovascular morbidity and mortality, but the specific molecular basis linking DM with increased vulnerability to cardiovascular injury remains incompletely understood. Methylglyoxal (MG), a precursor to advanced glycation end products (AGEs), is increased in diabetic patient plasma, but its role in diabetic cardiovascular complications is unclear. Thioredoxin (Trx), a cytoprotective molecule with antiapoptotic function, has been demonstrated to be vulnerable to glycative inhibition, but whether Trx is glycatively inhibited by MG, thus contributing to increased cardiac injury, has never been investigated. Cultured H9c2 cardiomyocytes were treated with MG (200 muM) for 6 days. The following were determined pre- and post-simulated ischemia-reperfusion (SI-R; 8 h of hypoxia followed by 3 h of reoxygenation): cardiomyocyte death/apoptosis, Trx expression and activity, AGE formation, Trx-apoptosis-regulating kinase-1 (Trx-ASK1) complex formation, and p38 mitogen-activated protein kinase (MAPK) phosphorylation and activity. Compared with vehicle, MG significantly increased SI-R-induced cardiomyocyte LDH release and apoptosis (P < 0.01). Prior to SI-R, Trx activity was reduced in MG-treated cells, but Trx expression was increased moderately. Moreover, Trx-ASK1 complex formation was reduced, and both p38 MAPK activity and phosphorylation were increased. To investigate the effects of MG on Trx directly, recombinant human Trx (hTrx) was incubated with MG in vitro. Compared with vehicle, MG incubation markedly increased CML formation (a glycation footprint) and inhibited Trx activity. Finally, glycation inhibitor aminoguanidine administration during MG treatment of cultured cells reduced AGE formation, increased Trx activity, restored Trx-ASK1 interaction, and reduced p38 MAPK phosphorylation and activity, caspase-3 activation, and LDH release (P < 0.01). We demonstrated for the first time that methylglyoxal sensitized cultured cardiomyocytes to SI-R injury by posttranslational modification of Trx via glycation. Therapeutic interventions scavenging AGE precursors may attenuate ischemic-reperfusion injury in hyperglycemic state diseases such as diabetes.

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“…However, analytical investigations were often limited to few selected compounds like glyoxal, methylglyoxal and 3-DG [5,12,[79][80][81][82][83][84][85]. A more comprehensive approach including important intermediates from a mechanistic point of view is needed, e.g.…”

Section: Relevance In Vivomentioning

confidence: 99%

Pathways of the Maillard reaction under physiological conditions

2016

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Initially investigated as a color formation process in thermally treated foods, nowadays, the relevance of the Maillard reaction in vivo is generally accepted. Many chronic and age-related diseases such as diabetes, uremia, atherosclerosis, cataractogenesis and Alzheimer's disease are associated with Maillard derived advanced glycation endproducts (AGEs) and α-dicarbonyl compounds as their most important precursors in terms of reactivity and abundance. However, the situation in vivo is very challenging, because Maillard chemistry is paralleled by enzymatic reactions which can lead to both, increases and decreases in certain AGEs. In addition, mechanistic findings established under the harsh conditions of food processing might not be valid under physiological conditions. The present review critically discusses the relevant α-dicarbonyl compounds as central intermediates of AGE formation in vivo with a special focus on fragmentation pathways leading to formation of amide-AGEs.

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Determination of glyoxal and methylglyoxal in the serum of diabetic patients by MEKC using stilbenediamine as derivatizing reagent

Cited by 36 publications

References 25 publications

Methylglyoxal Causes Dysfunction of Thioredoxin and Thioredoxin Reductase in Endothelial Cells

Methylglyoxal Causes Dysfunction of Thioredoxin and Thioredoxin Reductase in Endothelial Cells

Methylglyoxal increases cardiomyocyte ischemia-reperfusion injury via glycative inhibition of thioredoxin activity

Pathways of the Maillard reaction under physiological conditions

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