Glyoxal damages human aortic endothelial cells by perturbing the glutathione, mitochondrial membrane potential, and mitogen-activated protein kinase pathways

Chitosan/starch based unoxidized tannic acid modified microparticles for rapid hemostasis with broad spectrum antibacterial activity

The development of a rapid hemostat through a facile method with co-existing antibacterial activity and minimum erythrocyte lysis property stands as a major requirement in the field of hemostasis. Herein, a series of novel microparticle hemostats were synthesized using chitosan, different hydrothermally-treated starches, and cross-linked with tannic acid (TA) simultaneously in an unoxidized environment via ionotropic gelation method. Hemostats' comparative functional properties, such as adjustable antibacterial and erythrocyte compatibility upon various starch additions were evaluated. The in vivo hemostatic study revealed that the developed hemostats for mouse liver laceration and rat tail amputation had clotting times (13 s and 38 s, respectively) and blood loss (51 mg and 62 mg, respectively) similar to those of Celox™. The erythrocyte adhesion test suggested that erythrocyte distortion can be lowered by modifying the antibacterial hemostats with different starches. The broad-spectrum antibacterial efficacy of the hemostats remained intact against S. aureus (>90 %), E. coli (>80 %), and P. mirabilis bacteria upon starch modification. They also demonstrated high hemocompatibility (<3 % hemolysis ratio), moderate cell viability (>81 %), in vivo biodegradation, and angiogenesis indicating adequate biocompatibility and wound healing. The developed hemostats hold significant promise to be employed as rapid hemostatic agents for preventing major bleeding and bacterial infection in emergencies.

Glyoxal in Foods: Formation, Metabolism, Health Hazards, and Its Control Strategies

Glyoxal is a highly reactive aldehyde widely present in common diet and environment and inevitably generated through various metabolic pathways in vivo. Glyoxal is easily produced in diets high in carbohydrates and fats via the Maillard reaction, carbohydrate autoxidation, and lipid peroxidation, etc. This leads to dietary intake being a major source of exogenous exposure. Exposure to glyoxal has been positively associated with a number of metabolic diseases, such as diabetes mellitus, atherosclerosis, and Alzheimer's disease. It has been demonstrated that polyphenols, probiotics, hydrocolloids, and amino acids can reduce the content of glyoxal in foods via different mechanisms, thus reducing the risk of exogenous exposure to glyoxal and alleviating carbonyl stresses in the human body. This review discussed the formation and metabolism of glyoxal, its health hazards, and the strategies to reduce such health hazards. Future investigation of glyoxal from different perspectives is also discussed.

Communal interaction of glycation and gut microbes in diabetes mellitus, Alzheimer's disease, and Parkinson's disease pathogenesis

Diabetes and its complications, Alzheimer's disease (AD), and Parkinson's disease (PD) are increasing gradually, reflecting a global threat vis-à-vis expressing the essentiality of a substantial paradigm shift in research and remedial actions. Protein glycation is influenced by several factors, like time, temperature, pH, metal ions, and the half-life of the protein. Surprisingly, most proteins associated with metabolic and neurodegenerative disorders are generally long-lived and hence susceptible to glycation. Remarkably, proteins linked with diabetes, AD, and PD share this characteristic. This modulates protein's structure, aggregation tendency, and toxicity, highlighting renovated attention. Gut microbes and microbial metabolites marked their importance in human health and diseases. Though many scientific shreds of evidence are proposed for possible change and dysbiosis in gut flora in these diseases, very little is known about the mechanisms. Screening and unfolding their functionality in metabolic and neurodegenerative disorders is essential in hunting the gut treasure. Therefore, it is imperative to evaluate the role of glycation as a common link in diabetes and neurodegenerative diseases, which helps to clarify if modulation of nonenzymatic glycation may act as a beneficial therapeutic strategy and gut microbes/metabolites may answer some of the crucial questions. This review briefly emphasizes the common functional attributes of glycation and gut microbes, the possible linkages, and discusses current treatment options and therapeutic challenges.

Glyoxal in hyperglycaemic ischemic stroke - a cohort study

BACKGROUND

Hyperglycaemia is frequent in acute ischemic stroke and denotes a bad prognosis, even in the absence of pre-existing diabetes. However, in clinical trials treatment of elevated glucose levels with insulin did not improve stroke outcome, suggesting that collateral effects rather than hyperglycaemia itself aggravate ischemic brain damage. As reactive glucose metabolites, glyoxal and methylglyoxal are candidates for mediating the deleterious effects of hyperglycaemia in acute stroke.

METHODS

In 135 patients with acute stroke, we used liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) to measure glyoxal, methylglyoxal and several of their glycated amino acid derivatives in serum. Results were verified in a second cohort of 61 stroke patients. The association of serum concentrations with standard stroke outcome scales (NIHSS, mRS) was tested.

RESULTS

Glucose, glyoxal, methylglyoxal, and the glyoxal-derived glycated amino acid N_δ-(5-hydro-4-imidazolon-2-yl)ornithine (G-H1) were positively correlated with a bad stroke outcome at 3 months as measured by mRS90, at least in one of the two cohorts. However, the glycated amino acids N_ε-carboxyethyllysine (CEL) and in one cohort pyrraline showed an inverse correlation with stroke outcome probably reflecting lower food intake in severe stroke. Patients with a poor outcome had higher serum concentrations of glyoxal and methylglyoxal.

CONCLUSIONS

The glucose-derived α-dicarbonyl glyoxal and glycated amino acids arising from a reaction with glyoxal are associated with a poor outcome in ischemic stroke. Thus, lowering α-dicarbonyls or counteracting their action could be a therapeutic strategy for hyperglycaemic stroke.

Proteomics-based evaluation of the mechanism underlying vascular injury via DNA interstrand crosslinks, glutathione perturbation, mitogen-activated protein kinase, and Wnt and ErbB signaling pathways induced by crotonaldehyde

Crotonaldehyde (CRA)—one of the major environmental pollutants from tobacco smoke and industrial pollution—is associated with vascular injury (VI). We used proteomics to systematically characterize the presently unclear molecular mechanism of VI and to identify new related targets or signaling pathways after exposure to CRA. Cell survival assays were used to assess DNA damage, whereas oxidative stress was determined using colorimetric assays and by quantitative fluorescence study; additionally, cyclooxygenase-2, mitogen-activated protein kinase pathways, Wnt3a, β-catenin, phospho-ErbB2, and phospho-ErbB4 were assessed using ELISA. Proteins were quantitated via tandem mass tag-based liquid chromatography-mass spectrometry and bioinformatics analyses, and 34 differentially expressed proteins were confirmed using parallel reaction monitoring, which were defined as new indicators related to the mechanism underlying DNA damage; glutathione perturbation; mitogen-activated protein kinase; and the Wnt and ErbB signaling pathways in VI based on Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and protein–protein interaction network analyses. Parallel reaction monitoring confirmed significant (p < 0.05) upregulation (> 1.5-fold change) of 23 proteins and downregulation (< 0.667-fold change) of 11. The mechanisms of DNA interstrand crosslinks; glutathione perturbation; mitogen-activated protein kinase; cyclooxygenase-2; and the Wnt and ErbB signaling pathways may contribute to VI through their roles in DNA damage, oxidative stress, inflammation, vascular dysfunction, endothelial dysfunction, vascular remodeling, coagulation cascade, and the newly determined signaling pathways. Moreover, the Wnt and ErbB signaling pathways were identified as new disease pathways involved in VI. Taken together, the elucidated underlying mechanisms may help broaden existing understanding of the molecular mechanisms of VI induced by CRA.