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1.
Mol Med ; 30(1): 76, 2024 Jun 05.
Article En | MEDLINE | ID: mdl-38840067

BACKGROUND: Advanced glycation end product-modified low-density lipoprotein (AGE-LDL) is related to inflammation and the development of atherosclerosis. Additionally, it has been demonstrated that receptor for advanced glycation end products (RAGE) has a role in the condition known as calcific aortic valve disease (CAVD). Here, we hypothesized that the AGE-LDL/RAGE axis could also be involved in the pathophysiological mechanism of CAVD. METHODS: Human aortic valve interstitial cells (HAVICs) were stimulated with AGE-LDL following pre-treatment with or without interleukin 37 (IL-37). Low-density lipoprotein receptor deletion (Ldlr-/-) hamsters were randomly allocated to chow diet (CD) group and high carbohydrate and high fat diet (HCHFD) group. RESULTS: AGE-LDL levels were significantly elevated in patients with CAVD and in a hamster model of aortic valve calcification. Our in vitro data further demonstrated that AGE-LDL augmented the expression of intercellular cell adhesion molecule-1 (ICAM-1), interleukin-6 (IL-6) and alkaline phosphatase (ALP) in a dose-dependent manner through NF-κB activation, which was attenuated by nuclear factor kappa-B (NF-κB) inhibitor Bay11-7082. The expression of RAGE was augmented in calcified aortic valves, and knockdown of RAGE in HAVICs attenuated the AGE-LDL-induced inflammatory and osteogenic responses as well as NF-κB activation. IL-37 suppressed inflammatory and osteogenic responses and NF-κB activation in HAVICs. The vivo experiment also demonstrate that supplementation with IL-37 inhibited valvular inflammatory response and thereby suppressed valvular osteogenic activities. CONCLUSIONS: AGE-LDL promoted inflammatory responses and osteogenic differentiation through RAGE/NF-κB pathway in vitro and aortic valve lesions in vivo. IL-37 suppressed the AGE-LDL-induced inflammatory and osteogenic responses in vitro and attenuated aortic valve lesions in a hamster model of CAVD.


Aortic Valve Stenosis , Aortic Valve , Calcinosis , Glycation End Products, Advanced , Lipoproteins, LDL , NF-kappa B , Osteogenesis , Receptor for Advanced Glycation End Products , Signal Transduction , Animals , Aortic Valve/metabolism , Aortic Valve/pathology , Glycation End Products, Advanced/metabolism , NF-kappa B/metabolism , Humans , Calcinosis/metabolism , Calcinosis/pathology , Calcinosis/genetics , Receptor for Advanced Glycation End Products/metabolism , Receptor for Advanced Glycation End Products/genetics , Aortic Valve Stenosis/metabolism , Aortic Valve Stenosis/etiology , Aortic Valve Stenosis/pathology , Cricetinae , Osteogenesis/drug effects , Male , Lipoproteins, LDL/metabolism , Disease Models, Animal , Female , Middle Aged , Glycated Proteins
2.
Arch Dermatol Res ; 316(7): 338, 2024 Jun 07.
Article En | MEDLINE | ID: mdl-38847916

Diabetic foot ulcer (DFU) is a predominant complication of diabetes mellitus with poor prognosis accompanied by high amputation and mortality rates. Dang-Gui-Si-Ni decoction (DSD), as a classic formula with a long history in China, has been found to improve DFU symptoms. However, mechanism of DSD for DFU therapy remains unclear with no systematic elaboration. In vivo, following establishment of DFU rat model, DSD intervention with low, medium and high doses was done, with Metformin (DM) as a positive control group. With wound healing detection, pathological changes by HE staining, inflammatory factor expression by ELISA and qRT-PCR, oxidative stress levels by ELISA, and AGEs/RAGE/TGF-ß/Smad2/3 expression by Western blot were performed. In vitro, intervention with LY2109761 (TGF-ß pathway inhibitor) based on DSD treatment in human dermal fibroblast-adult (HDF-a) cells was made. Cell viability by CCK8, migration ability by cell scratch, apoptosis by flow cytometry, and AGEs/RAGE/TGF-ß/Smad2/3 expression by Western blot were measured. DFU rats exhibited elevated AGEs/RAGE expression, whereas decreased TGF-ß1 and p-Smad3/Smad3 protein expression, accompanied by higher IL-1ß, IL-6, TNF-α levels, and oxidative stress. DSD intervention reversed above effects. Glucose induction caused lower cell viability, migration, TGF-ß1 and p-Smad3/Smad3 protein expression, with increased apoptosis and AGEs/RAGE expression in HDF-a cells. These effects were reversed after DSD intervention, and further LY2109761 intervention inhibited DSD effects in cells. DSD intervention may facilitate wound healing in DFU by regulating expression of AGEs/RAGE/TGF-ß/Smad2/3, providing scientific experimental evidence for DSD clinical application for DFU therapy.


Diabetic Foot , Drugs, Chinese Herbal , Glycation End Products, Advanced , Smad2 Protein , Smad3 Protein , Wound Healing , Diabetic Foot/drug therapy , Diabetic Foot/metabolism , Diabetic Foot/pathology , Animals , Wound Healing/drug effects , Rats , Drugs, Chinese Herbal/pharmacology , Smad2 Protein/metabolism , Humans , Smad3 Protein/metabolism , Glycation End Products, Advanced/metabolism , Male , Receptor for Advanced Glycation End Products/metabolism , Signal Transduction/drug effects , Transforming Growth Factor beta/metabolism , Rats, Sprague-Dawley , Oxidative Stress/drug effects , Apoptosis/drug effects , Disease Models, Animal , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Experimental/drug therapy , Fibroblasts/metabolism , Fibroblasts/drug effects , Cell Movement/drug effects , Cell Survival/drug effects
3.
Virulence ; 15(1): 2352476, 2024 12.
Article En | MEDLINE | ID: mdl-38741276

Staphylococcus aureus (S. aureus) is well known for its biofilm formation ability and is responsible for serious, chronic refractory infections worldwide. We previously demonstrated that advanced glycation end products (AGEs), a hallmark of chronic hyperglycaemia in diabetic tissues, enhanced biofilm formation by promoting eDNA release via sigB upregulation in S. aureus, contributing to the high morbidity and mortality of patients presenting a diabetic foot ulcer infection. However, the exact regulatory network has not been completely described. Here, we used pull-down assay and LC-MS/MS to identify the GlmS as a candidate regulator of sigB in S. aureus stimulated by AGEs. Dual-luciferase assays and electrophoretic mobility shift assays (EMSAs) revealed that GlmS directly upregulated the transcriptional activity of sigB. We constructed NCTC 8325 ∆glmS for further validation. qRT-PCR analysis revealed that AGEs promoted both glmS and sigB expression in the NCTC 8325 strain but had no effect on NCTC 8325 ∆glmS. NCTC 8325 ∆glmS showed a significant attenuation in biofilm formation and virulence factor expression, accompanied by a decrease in sigB expression, even under AGE stimulation. All of the changes, including pigment deficiency, decreased haemolysis ability, downregulation of hla and hld expression, and less and sparser biofilms, indicated that sigB and biofilm formation ability no longer responded to AGEs in NCTC 8325 ∆glmS. Our data extend the understanding of GlmS in the global regulatory network of S. aureus and demonstrate a new mechanism by which AGEs can upregulate GlmS, which directly regulates sigB and plays a significant role in mediating biofilm formation and virulence factor expression.


Bacterial Proteins , Biofilms , Gene Expression Regulation, Bacterial , Glycation End Products, Advanced , Staphylococcal Infections , Staphylococcus aureus , Virulence Factors , Biofilms/growth & development , Staphylococcus aureus/genetics , Staphylococcus aureus/pathogenicity , Virulence Factors/genetics , Glycation End Products, Advanced/metabolism , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Staphylococcal Infections/microbiology , Sigma Factor/genetics , Sigma Factor/metabolism , Humans
4.
Int J Mol Sci ; 25(9)2024 Apr 27.
Article En | MEDLINE | ID: mdl-38732004

Age-related macular degeneration (AMD) is an age-related disorder that is a global public health problem. The non-enzymatic Maillard reaction results in the formation of advanced glycation end products (AGEs). Accumulation of AGEs in drusen plays a key role in AMD. AGE-reducing drugs may contribute to the prevention and treatment of AGE-related disease. Fructosamine oxidase (FAOD) acts on fructosyl lysine and fructosyl valine. Based upon the published results of fructosamine 3-kinase (FN3K) and FAOD obtained in cataract and presbyopia, we studied ex vivo FAOD treatment as a non-invasive AMD therapy. On glycolaldehyde-treated porcine retinas, FAOD significantly reduced AGE autofluorescence (p = 0.001). FAOD treatment results in a breakdown of AGEs, as evidenced using UV fluorescence, near-infrared microspectroscopy on stained tissue sections of human retina, and gel permeation chromatography. Drusen are accumulations of AGEs that build up between Bruch's membrane and the retinal pigment epithelium. On microscopy slides of human retina affected by AMD, a significant reduction in drusen surface to 45 ± 21% was observed following FAOD treatment. Enzymatic digestion followed by mass spectrometry of fructose- and glucose-based AGEs (produced in vitro) revealed a broader spectrum of substrates for FAOD, as compared to FN3K, including the following: fructosyllysine, carboxymethyllysine, carboxyethyllysine, and imidazolone. In contrast to FN3K digestion, agmatine (4-aminobutyl-guanidine) was formed following FAOD treatment in vitro. The present study highlights the therapeutic potential of FAOD in AMD by repairing glycation-induced damage.


Glycation End Products, Advanced , Macular Degeneration , Macular Degeneration/drug therapy , Macular Degeneration/metabolism , Macular Degeneration/pathology , Humans , Glycation End Products, Advanced/metabolism , Animals , Swine , Retina/metabolism , Retina/drug effects , Retina/pathology , Amino Acid Oxidoreductases
5.
Food Chem ; 452: 139594, 2024 Sep 15.
Article En | MEDLINE | ID: mdl-38749142

Protein glycation closely intertwines with the pathogenesis of various diseases, sparking a growing interest in exploring natural antiglycation agents. Herein, high-purity betacyanins (betanin and phyllocactin) derived from Hylocereus polyrhizus peel were studied for their antiglycation potential using an in vitro bovine serum albumin (BSA)-glucose model. Notably, betacyanins outperformed aminoguanidine, a recognized antiglycation agent, in inhibiting glycation product formation across different stages, especially advanced glycation end-products (AGEs). Interestingly, phyllocactin displayed stronger antiglycation activity than betanin. Subsequent mechanistic studies employing molecular docking analysis and fluorescence quenching assay unveiled that betacyanins interact with BSA endothermically and spontaneously, with hydrophobic forces playing a dominant role. Remarkably, phyllocactin demonstrated higher binding affinity and stability to BSA than betanin. Furthermore, the incorporation of betacyanins into bread dose-dependently suppressed AGEs formation during baking and shows promise for inhibiting in vivo glycation process post-consumption. Overall, this study highlights the substantial potential of betacyanins as natural antiglycation agents.


Betacyanins , Bread , Glycation End Products, Advanced , Molecular Docking Simulation , Plant Extracts , Serum Albumin, Bovine , Glycosylation , Serum Albumin, Bovine/chemistry , Serum Albumin, Bovine/metabolism , Glycation End Products, Advanced/metabolism , Glycation End Products, Advanced/chemistry , Betacyanins/chemistry , Betacyanins/pharmacology , Plant Extracts/chemistry , Plant Extracts/pharmacology , Bread/analysis , Cactaceae/chemistry , Cactaceae/metabolism , Animals , Cattle
6.
Nutrients ; 16(9)2024 May 05.
Article En | MEDLINE | ID: mdl-38732638

As the most serious of the many worse new pathological changes caused by diabetes, there are many risk factors for the occurrence and development of diabetic retinopathy (DR). They mainly include hyperglycemia, hypertension, hyperlipidemia and so on. Among them, hyperglycemia is the most critical cause, and plays a vital role in the pathological changes of DR. High-sucrose diets (HSDs) lead to elevated blood glucose levels in vivo, which, through oxidative stress, inflammation, the production of advanced glycation end products (AGEs) and vascular endothelial growth factor (VEGF), cause plenty of pathological damages to the retina and ultimately bring about loss of vision. The existing therapies for DR primarily target the terminal stage of the disease, when irreversible visual impairment has appeared. Therefore, early prevention is particularly critical. The early prevention of DR-related vision loss requires adjustments to dietary habits, mainly by reducing sugar intake. This article primarily discusses the risk factors, pathophysiological processes and molecular mechanisms associated with the development of DR caused by HSDs. It aims to raise awareness of the crucial role of diet in the occurrence and progression of DR, promote timely changes in dietary habits, prevent vision loss and improve the quality of life. The aim is to make people aware of the importance of diet in the occurrence and progression of DR. According to the dietary modification strategies that we give, patients can change their poor eating habits in a timely manner to avoid theoretically avoidable retinopathy and obtain an excellent prognosis.


Diabetic Retinopathy , Disease Progression , Humans , Diabetic Retinopathy/etiology , Diabetic Retinopathy/prevention & control , Risk Factors , Dietary Sucrose/adverse effects , Oxidative Stress , Blood Glucose/metabolism , Diet/adverse effects , Feeding Behavior , Glycation End Products, Advanced/metabolism , Glycation End Products, Advanced/adverse effects
7.
Carbohydr Res ; 540: 109125, 2024 Jun.
Article En | MEDLINE | ID: mdl-38703663

Di-d-psicose anhydride (DPA), derived from functional rare saccharide as d-psicose, is investigated for its strong chelating ability. Methylglyoxal (MGO), an important precursor of advanced glycation end-products (AGEs), promotes obesity, and causes complications such as diabetic nephropathy. On mesangial cells, DPA can substantially reduce the negative effects of MGO. DPA effectively trapping MGO in mesangial cells. The bonding properties of the DPA-MGO adduct were discussed by mass spectrometry and nuclear magnetic resonance (NMR). The NMR spectra of the DPA-MGO adduct provide evidence for chelation bonding. The inhibition of AGE formation and the mass spectrometry results of the DPA-MGO adduct indicate that DPA can scavenge MGO at a molar ratio of 1:1. DPA suppressed 330 % of the up-regulated receptor for an AGEs protein expression to a normal level and restored the suppressed glyoxalase 1 level to 86 % of the normal group. This research provides important evidence and theoretical basis for the development of AGE inhibitors derived from rare saccharide.


Diabetic Nephropathies , Glycation End Products, Advanced , Pyruvaldehyde , Pyruvaldehyde/chemistry , Diabetic Nephropathies/drug therapy , Diabetic Nephropathies/metabolism , Diabetic Nephropathies/prevention & control , Glycation End Products, Advanced/metabolism , Glycation End Products, Advanced/antagonists & inhibitors , Mesangial Cells/drug effects , Mesangial Cells/metabolism , Lactoylglutathione Lyase/antagonists & inhibitors , Lactoylglutathione Lyase/metabolism , Humans , Receptor for Advanced Glycation End Products/metabolism , Receptor for Advanced Glycation End Products/antagonists & inhibitors , Anhydrides/chemistry , Chelating Agents/chemistry , Chelating Agents/pharmacology
8.
Free Radic Biol Med ; 220: 192-206, 2024 Aug 01.
Article En | MEDLINE | ID: mdl-38734265

Enhanced formation of advanced glycation end products (AGEs) is a pivotal factor in diabetes pathophysiology, increasing the risk of diabetic complications. Nε-carboxy-methyl-lysine (CML) is one of the most relevant AGEs found in several tissues including the peripheral blood of diabetic subjects. Despite recognizing diabetes as a risk factor for neurodegenerative diseases and the documented role of mitochondrial abnormalities in this connection, the impact of CML on neuronal mitochondria and its contribution to diabetes-related neurodegeneration remain uncertain. Here, we evaluated the effects of CML in differentiated SH-SY5Y human neuroblastoma cells. Due to the association between mitochondrial dysfunction and increased production of reactive oxygen species (ROS), the possible protective effects of MitoTempo, a mitochondria-targeted antioxidant, were also evaluated. Several parameters were assessed namely cells viability, mitochondrial respiration and membrane potential, ATP and ROS production, Ca2+ levels, mitochondrial biogenesis and dynamics, mito/autophagy, endoplasmic reticulum (ER) stress and amyloidogenic and synaptic integrity markers. CML caused pronounced mitochondrial defects characterized by a significant decrease in mitochondrial respiration, membrane potential, and ATP production and an increase in ROS production. An accumulation of individual mitochondria associated with disrupted mitochondrial networks was also observed. Furthermore, CML caused mitochondrial fusion and a decrease in mitochondrial mass and induced ER stress associated with altered unfolded protein response and Ca2+ dyshomeostasis. Moreover, CML increased the protein levels of ß-secretase-1 and amyloid precursor protein, key proteins involved in Alzheimer's Disease pathophysiology. All these effects contributed to the decline in neuronal cells viability. Notable, MitoTempo was able to counteract most of CML-mediated mitochondrial defects and neuronal cells injury and death. Overall, these findings suggest that CML induces pronounced defects in neuronal mitochondria and ER stress, predisposing to neurodegenerative events. More, our observations suggest that MitoTempo holds therapeutic promise in mitigating CML-induced mitochondrial imbalance and neuronal damage and death.


Endoplasmic Reticulum Stress , Lysine , Membrane Potential, Mitochondrial , Mitochondria , Neurons , Organophosphorus Compounds , Reactive Oxygen Species , Humans , Lysine/analogs & derivatives , Lysine/metabolism , Mitochondria/metabolism , Mitochondria/pathology , Mitochondria/drug effects , Neurons/metabolism , Neurons/pathology , Neurons/drug effects , Reactive Oxygen Species/metabolism , Organophosphorus Compounds/pharmacology , Endoplasmic Reticulum Stress/drug effects , Membrane Potential, Mitochondrial/drug effects , Cell Line, Tumor , Cell Survival/drug effects , Glycation End Products, Advanced/metabolism , Homeostasis , Antioxidants/pharmacology , Antioxidants/metabolism , Neuroblastoma/pathology , Neuroblastoma/metabolism , Piperidines
9.
J Mech Behav Biomed Mater ; 155: 106577, 2024 Jul.
Article En | MEDLINE | ID: mdl-38759587

The present study simulates the fracture behavior of diabetic cortical bone with high levels of advanced glycation end-products (AGEs) under dynamic loading. We consider that the increased AGEs in diabetic cortical bone degrade the materials heterogeneity of cortical bone through a reduction in critical energy release rates of the microstructural features. To simulate the initiation and propagation of cracks, we implement a phase field fracture framework on 2D models of human tibia cortical microstructure. The simulations show that the mismatch between the fracture properties (e.g., critical energy release rate) of osteons and interstitial tissue due to high AGEs contents can change crack growth trajectories. The results show crack branching in the cortical microstructure under dynamic loading is affected by the mismatches related to AGEs. In addition, we observe cortical features such as osteons and cement lines can prevent multiple cracking under dynamic loading even with changing the mismatches due to high AGEs. Furthermore, under dynamic loading, some toughening mechanisms can be activated and deactivated with different AGEs contents. In conclusion, the current findings present that the combination of the loading type and materials heterogeneity of microstructural features can change the fracture response of diabetic cortical bone and its fragility.


Cortical Bone , Glycation End Products, Advanced , Weight-Bearing , Humans , Cortical Bone/metabolism , Glycation End Products, Advanced/metabolism , Biomechanical Phenomena , Fractures, Bone/metabolism , Tibia/metabolism , Finite Element Analysis , Stress, Mechanical
10.
Phytomedicine ; 129: 155654, 2024 Jul.
Article En | MEDLINE | ID: mdl-38723525

BACKGROUND: Wenqingyin (WQY), an ancient Chinese medicinal agent, has been extensively used in treating infectious ailments throughout history. However, the anti-sepsis mechanism remains unknown. PURPOSE: This study investigated the diverse mechanisms of WQY in mitigating sepsis-induced acute lung injury (ALI). Additionally, the effects of WQY were validated using biological experiments. METHODS: This study combined UHPLC-Orbitrap-HRMS analysis and network pharmacology to predict the potential anti-sepsis mechanism of WQY. Sepsis-induced ALI models were established in vivo via intraperitoneal lipopolysaccharide (LPS) administration and in vitro by LPS-stimulated RAW 264.7 macrophages. Various techniques, including hematoxylin-eosin staining, TUNEL, qPCR, and ELISA, were used to assess lung damage and quantify inflammatory cytokines. Inflammatory cell infiltration was visualized through immunohistochemistry. Hub targets and signaling pathways were identified using Western blotting, immunohistochemistry, and immunofluorescence staining. RESULTS: Seventy-five active components and 237 associated targets were acquired, with 145 of these targets overlapping with processes related to sepsis. Based on the comprehensive protein-protein interaction network analysis, JUN, AKT1, TP53, IL-6, HSP90AA1, CASP3, VEGFA, IL-1ß, RELA, and EGFR may be targets of WQY for sepsis. Analysis of the Kyoto Gene and Genome Encyclopedia revealed that WQY is implicated in the advanced glycation end products/receptor for advanced glycation end products (AGE/RAGE) signaling pathway. In vivo, WQY alleviated sepsis-induced ALI, suppressing proinflammatory cytokines and inhibiting macrophage/neutrophil infiltration. In vitro, WQY reduced TNF-α, IL-6, and IL-1ß in LPS-induced RAW 264.7 macrophages. Furthermore, we verified that WQY protected against sepsis-induced ALI by regulating the RAGE pathway for the first time. Baicalin, coptisine, and paeoniflorin may be the effective components of WQY that inhibit RAGE. CONCLUSION: The primary mechanism of WQY in combating sepsis-induced ALI involves controlling RAGE levels and the PI3K/AKT pathway, suppressing inflammation, and mitigating lung damage. This study establishes a scientific foundation for understanding the mechanism of WQY and its clinical use in treating sepsis.


Acute Lung Injury , Drugs, Chinese Herbal , Lipopolysaccharides , Receptor for Advanced Glycation End Products , Sepsis , Signal Transduction , Acute Lung Injury/drug therapy , Animals , Sepsis/complications , Sepsis/drug therapy , Mice , RAW 264.7 Cells , Drugs, Chinese Herbal/pharmacology , Receptor for Advanced Glycation End Products/metabolism , Signal Transduction/drug effects , Male , Cytokines/metabolism , Mice, Inbred C57BL , Disease Models, Animal , Network Pharmacology , Protective Agents/pharmacology , Glycation End Products, Advanced/metabolism
11.
Int J Biol Macromol ; 269(Pt 2): 132257, 2024 Jun.
Article En | MEDLINE | ID: mdl-38729492

Low-density lipoprotein (LDL) transports cholesterol to various tissues via the blood. Glycation of LDL occurs during hyperglycemic condition which is characterised by persistently high blood glucose level. Circulating erythrocytes can come in direct contact with glycated LDL (G-LDL). The objective of this study was to investigate the effect of G-LDL on human erythrocytes, specifically on hemoglobin, intracellular generation of reactive species and the antioxidant defence system. Isolated erythrocytes were incubated with G-LDL (3 and 6 mg/ml) and native LDL (6 mg/ml) at 37 °C for 24 h. Native LDL and G-LDL untreated erythrocytes were similarly incubated at 37 °C and served as control. G-LDL treatment increased hemolysis compared to control and native LDL-treated erythrocytes. Incubation of erythrocytes with G-LDL led to an increase in protein oxidation and lipid peroxidation while greatly decreasing the total sulfhydryl content. It also significantly enhanced hemoglobin oxidation, heme degradation, and the release of free iron moiety. Treatment with G-LDL led to an appreciable increase in the production of reactive oxygen and nitrogen species. The antioxidant power and activities of major antioxidant enzymes were drastically reduced, while critical membrane-bound enzymes were inhibited. The surface morphology of G-LDL-treated erythrocytes was altered leading to the formation of echinocytes. Importantly, treatment of erythrocytes with native LDL did not significantly affect the above-mentioned parameters and values were similar to the corresponding controls. Thus, G-LDL is cytotoxic to human erythrocytes and causes oxidative damage to cell components. This can reduce the oxygen-transporting ability of blood and also result in red cell senescence and anemia.


Erythrocytes , Hemoglobins , Hemolysis , Lipoproteins, LDL , Oxidation-Reduction , Reactive Oxygen Species , Humans , Erythrocytes/metabolism , Erythrocytes/drug effects , Lipoproteins, LDL/metabolism , Lipoproteins, LDL/pharmacology , Reactive Oxygen Species/metabolism , Hemoglobins/metabolism , Hemolysis/drug effects , Oxidation-Reduction/drug effects , Antioxidants/pharmacology , Lipid Peroxidation/drug effects , Glycation End Products, Advanced/metabolism , Glycation End Products, Advanced/pharmacology , Oxidative Stress/drug effects , Heme/metabolism , Heme/pharmacology , Glycated Proteins
12.
Biochem Biophys Res Commun ; 721: 150107, 2024 Aug 20.
Article En | MEDLINE | ID: mdl-38781658

Diabetes-mediated development of micro and macro-vascular complications is a global concern. One of the factors is hyperglycemia induced the non-enzymatic formation of advanced glycation end products (AGEs). Accumulated AGEs bind with receptor of AGEs (RAGE) causing inflammation, oxidative stress and extracellular matrix proteins (ECM) modifications responsible for fibrosis, cell damage and tissue remodeling. Moreover, during hyperglycemia, aldosterone (Aldo) secretion increases, and its interaction with mineralocorticoid receptor (MR) through genomic and non-genomic pathways leads to inflammation and fibrosis. Extensive research on individual involvement of AGEs-RAGE and Aldo-MR pathways in the development of diabetic nephropathy (DN), cardiovascular diseases (CVDs), and impaired immune system has led to the discovery of therapeutic drugs. Despite mutual repercussions, the cross-talk between AGEs-RAGE and Aldo-MR pathways remains unresolved. Hence, this review focuses on the possible interaction of Aldo and glycation in DN and CVDs, considering the clinical significance of mutual molecular targets.


Aldosterone , Glycation End Products, Advanced , Receptor for Advanced Glycation End Products , Humans , Aldosterone/metabolism , Glycation End Products, Advanced/metabolism , Animals , Receptor for Advanced Glycation End Products/metabolism , Diabetic Nephropathies/metabolism , Diabetic Nephropathies/pathology , Receptors, Mineralocorticoid/metabolism , Diabetes Complications/metabolism , Diabetes Complications/pathology , Glycosylation
13.
Food Chem ; 452: 139532, 2024 Sep 15.
Article En | MEDLINE | ID: mdl-38705120

This study aimed to better understand whether and how the reactive 1,2-dicarbonyl precursors of advanced glycation end products (AGEs), glyoxal (GO) and methylglyoxal (MGO), cross the intestinal barrier by studying their transport in the in vitro Caco-2 transwell system. The results reveal that GO, MGO and Nε-(carboxymethyl)lysine (CML), the latter studied for comparison, are transported across the intestinal cell layer via both active and passive transport and accumulate in the cells, albeit all to a limited extent. Besides, the transport of the dicarbonyl compounds was only partially affected by the presence of amino acids and protein, suggesting that scavenging by a food matrix will not fully prevent their intestinal absorption. Our study provides new insights into the absorption of the two major food-borne dicarbonyl AGE precursors and provides evidence of their potential systemic bioavailability but also of factors limiting their contribution to the overall exposome.


Glycation End Products, Advanced , Glyoxal , Pyruvaldehyde , Humans , Caco-2 Cells , Glycation End Products, Advanced/metabolism , Glycation End Products, Advanced/chemistry , Pyruvaldehyde/metabolism , Glyoxal/metabolism , Glyoxal/chemistry , Models, Biological , Biological Transport , Intestinal Absorption
14.
J Cachexia Sarcopenia Muscle ; 15(3): 883-896, 2024 Jun.
Article En | MEDLINE | ID: mdl-38575520

BACKGROUND: Glycative stress, characterized by the formation and accumulation of advanced glycation end products (AGEs) associated with protein glycation reactions, has been implicated in inducing a decline of muscle function. Although the inverse correlation between glycative stress and muscle mass and strength has been demonstrated, the underlying molecular mechanisms are not fully understood. This study aimed to elucidate how glycative stress affects the skeletal muscle, particularly the adaptive muscle response to hypertrophic stimuli and its molecular mechanism. METHODS: Male C57BL/6NCr mice were randomly divided into the following two groups: the bovine serum albumin (BSA)-treated and AGE-treated groups. Mice in the AGE-treated group were intraperitoneally administered AGEs (0.5 mg/g) once daily, whereas those in the BSA-treated group received an equal amount of BSA (0.5 mg/g) as the vehicle control. After 7 days of continuous administration, the right leg plantaris muscle of mice in each group underwent functional overload treatment by synergist ablation for 7 days to induce muscle hypertrophy. In in vitro studies, cultured C2C12 myocytes were treated with AGEs (1 mg/mL) to examine cell adhesion and cell membrane permeability. RESULTS: Continuous AGE administration increased the levels of fluorescent AGEs, Nε-(carboxymethyl) lysine, and methylglyoxal-derived hydroimidazolone-1 in both plasma and skeletal muscle. Plantaris muscle weight, muscle fibre cross-sectional area, protein synthesis rate, and the number of myonuclei increased with functional overload in both groups; however, the increase was significantly reduced by AGE treatment. Some muscles of AGE-treated mice were destroyed by functional overload. Proteomic analysis was performed to explore the mechanisms of muscle hypertrophy suppression and myofibre destruction by AGEs. When principal component analysis was performed on 4659 data obtained by proteomic analysis, AGE treatment was observed to affect protein expression only in functionally overloaded muscles. Enrichment analysis of the 436 proteins extracted using the K-means method further identified a group of proteins involved in cell adhesion. Consistent with this finding, dystrophin-glycoprotein complex proteins and cell adhesion-related proteins were confirmed to increase with functional overload; however, this was attenuated by AGE treatment. Additionally, the treatment of C2C12 muscle cells with AGEs inhibited their ability to adhere and increased cell membrane permeability. CONCLUSIONS: This study indicates that glycative stress may be a novel pathogenic factor in skeletal muscle dysfunctions by causing loss of membrane integrity and preventing muscle mass gain.


Cell Membrane , Glycation End Products, Advanced , Hypertrophy , Muscle, Skeletal , Animals , Mice , Muscle, Skeletal/pathology , Muscle, Skeletal/metabolism , Muscle, Skeletal/drug effects , Glycation End Products, Advanced/metabolism , Cell Membrane/metabolism , Male , Disease Models, Animal
15.
Biol Pharm Bull ; 47(4): 791-795, 2024.
Article En | MEDLINE | ID: mdl-38583950

The number of patients with type 2 diabetes is increasing worldwide. The mechanisms leading to type 2 diabetes and its complications is being researched; however, the pathological mechanisms of diabetes in the small intestine remain unclear. Therefore, we examined these pathological mechanisms in the small intestine using a mouse model of type 2 diabetes (KK-Ay/TaJcl) aged 10 and 50 weeks. The results showed that diabetes worsened with age in the mice with type 2 diabetes. In these mice, advanced glycation end products (AGEs) in the small intestine and mast cell expression increased, whereas diamine oxidase (DAO) decreased; increased tumor necrosis factor (TNF)-α and histamine levels in the plasma and small intestine were also detected. Additionally, the expression of zonula occludens (ZO)-1 and Claudin1 and cell adhesion molecules in the small intestine reduced. These results exacerbated with age. These findings indicate that type 2 diabetes causes AGE/mast cell/histamine and TNF-α signal transmission in the small intestine and decreases small intestinal wall cell adhesion molecules cause TNF-α and histamine to flow into the body, worsening the diabetic condition. In addition, this sequence of events is suggested to be strengthened in aged mice with type 2 diabetes, thus exacerbating the disease. These findings of this study may facilitate the elucidation of the pathological mechanisms of type 2 diabetes and its associated complications.


Diabetes Mellitus, Type 2 , Humans , Diabetes Mellitus, Type 2/metabolism , Tumor Necrosis Factor-alpha/metabolism , Histamine/metabolism , Intestine, Small/metabolism , Cell Adhesion Molecules , Glycation End Products, Advanced/metabolism
16.
J Diabetes ; 16(4): e13548, 2024 Apr.
Article En | MEDLINE | ID: mdl-38599828

OBJECTIVE: Several studies have demonstrated a significant association between the presence of the ear lobe crease (ELC) and cardiovascular disease. Advanced glycation end-products (AGEs) can affect the structures and functions of proteins and contribute to the development of diabetic complications. However, few studies have reported the relationship between AGEs and ELC. The purpose of this study was to investigate the correlation of skin autofluorescence (SAF)-AGEage (SAF-AGEs × age/100) with ELC. METHODS: This cross-sectional study enrolled 6500 eligible participants from two communities in Beijing. Skin autofluorescence (SAF) was used to measure skin AGEs (SAF-AGEs). SAF-AGEage was defined as AGEs × age/100. Binary logistic regression analysis and linear regression analysis nested in logistic models were applied to test outcomes. RESULTS: The overall prevalence of ELC with an average age of 62.7 years participants was 57.1% (n = 3714). Age, fasting blood glucose, systolic blood pressure, and lipoprotein cholesterol were all greater in participants with ELC. ELC-positive participants had higher prevalence of coronary heart disease. Logistic analysis showed a significantly positive relationship between quartiles of SAF-AGEage and ELC (odds ratio [OR] 1.526, 95% CI 1.324-1.759; OR 2.072, CI 1.791-2.396; and OR 2.983, CI 2.551-3.489) for the multivariate-adjusted models, respectively. Stratified research revealed that those with a history of diabetes, hypertension, or coronary heart disease experienced the connection between SAF-AGEage and ELC. CONCLUSION: ELC is associated with coronary heart disease, and the SAF-AGE has a potential role in ELC development in elder people.


Coronary Disease , Diabetes Mellitus , Humans , Aged , Middle Aged , Aged, 80 and over , Cross-Sectional Studies , Glycation End Products, Advanced/metabolism , Diabetes Mellitus/epidemiology , Diabetes Mellitus/metabolism , Skin/metabolism
17.
Endocr Regul ; 58(1): 57-67, 2024 Jan 01.
Article En | MEDLINE | ID: mdl-38563294

Advanced glycation end products (AGEs) are a diverse group of compounds that are formed as a result of the non-enzymatic reaction between a reducing sugar such as glucose and the free NH2 groups of an amino acid in a protein or other biomolecule. The chemical reaction, by which these products are generated, is known as the Maillard reaction and occurs as a part of the body's normal metabolism. Such a reaction is enhanced during diabetes due to hyperglycemia, but it can also occur during the preparation, processing, and preservation of certain foods. Therefore, AGEs can also be obtained from the diet (d-AGE) and contribute to an increase of the total serum pool of these compounds. They have been implicated in a wide variety of pathological processes, mainly because of their ability to induce inflammatory responses and oxidative stress increase. They are extensively accumulated as a part of the normal aging, especially in tissues rich in long half-life proteins, which can compromise the physiology of these tissues. d-AGEs are abundant in diets rich in processed fats and sugars. This review is addressed to the current knowledge on these products and their impact on the immunomodulation of various mechanisms that may contribute to exacerbation of the diabetes pathophysiology.


Diabetes Mellitus , Glycation End Products, Advanced , Humans , Glycation End Products, Advanced/metabolism , Diet/adverse effects , Maillard Reaction , Inflammation
18.
J Drugs Dermatol ; 23(4): SF378083s5-SF378083s10, 2024 Apr 01.
Article En | MEDLINE | ID: mdl-38564405

Skin aging is influenced by various exogenous and endogenous factors, ranging from ultraviolet (UV) light exposure and environmental toxins to biological sources, such as those that arise from normal metabolic processes (eg, free radicals). Glycation is the normal process by which glucose and other reducing sugars react with proteins to form an array of heterogeneous biomolecular structures known as advanced glycation end-products (AGEs) over time. However, AGEs are toxic to human cells and are implicated in the acceleration of inflammatory and oxidative processes, with their accumulation in the skin being associated with increased skin dulling and yellowing, fine lines, wrinkles, and skin laxity. Clinicians should become cognizant of how AGEs develop, what their biological consequences are, and familiarize themselves with available strategies to mitigate their formation. J Drugs Dermatol.  2024;23:4(Suppl 1):s5-10.


Glycation End Products, Advanced , Maillard Reaction , Humans , Glycation End Products, Advanced/metabolism , Glycation End Products, Advanced/toxicity , Sugars/adverse effects , Sugars/metabolism , Skin/metabolism , Free Radicals/metabolism
19.
Cardiovasc Diabetol ; 23(1): 140, 2024 Apr 25.
Article En | MEDLINE | ID: mdl-38664681

BACKGROUND: Diabetic vascular remodeling is the most important pathological basis of diabetic cardiovascular complications. The accumulation of advanced glycation end products (AGEs) caused by elevated blood glucose promotes the proliferation and migration of vascular smooth muscle cells (VSMCs), leading to arterial wall thickening and ultimately vascular remodeling. Therefore, the excessive proliferation and migration of VSMCs is considered as an important therapeutic target for vascular remodeling in diabetes mellitus. However, due to the lack of breakthrough in experiments, there is currently no effective treatment for the excessive proliferation and migration of VSMCs in diabetic patients. Bcl-2-associated athanogene 3 (BAG3) protein is a multifunctional protein highly expressed in skeletal muscle and myocardium. Previous research has confirmed that BAG3 can not only regulate cell survival and apoptosis, but also affect cell proliferation and migration. Since the excessive proliferation and migration of VSMCs is an important pathogenesis of vascular remodeling in diabetes, the role of BAG3 in the excessive proliferation and migration of VSMCs and its molecular mechanism deserve further investigation. METHODS: In this study, BAG3 gene was manipulated in smooth muscle to acquire SM22αCre; BAG3FL/FL mice and streptozotocin (STZ) was used to simulate diabetes. Expression of proteins and aortic thickness of mice were detected by immunofluorescence, ultrasound and hematoxylin-eosin (HE) staining. Using human aorta smooth muscle cell line (HASMC), cell viability was measured by CCK-8 and proliferation was measured by colony formation experiment. Migration was detected by transwell, scratch experiments and Phalloidin staining. Western Blot was used to detect protein expression and Co-Immunoprecipitation (Co-IP) was used to detect protein interaction. RESULTS: In diabetic vascular remodeling, AGEs could promote the interaction between BAG3 and signal transducer and activator of transcription 3 (STAT3), leading to the enhanced interaction between STAT3 and Janus kinase 2 (JAK2) and reduced interaction between STAT3 and extracellular signal-regulated kinase 1/2 (ERK1/2), resulting in accumulated p-STAT3(705) and reduced p-STAT3(727). Subsequently, the expression of matrix metallopeptidase 2 (MMP2) is upregulated, thus promoting the migration of VSMCs. CONCLUSIONS: BAG3 upregulates the expression of MMP2 by increasing p-STAT3(705) and decreasing p-STAT3(727) levels, thereby promoting vascular remodeling in diabetes. This provides a new orientation for the prevention and treatment of diabetic vascular remodeling.


Adaptor Proteins, Signal Transducing , Apoptosis Regulatory Proteins , Cell Movement , Cell Proliferation , Muscle, Smooth, Vascular , Myocytes, Smooth Muscle , STAT3 Transcription Factor , Signal Transduction , Vascular Remodeling , STAT3 Transcription Factor/metabolism , Muscle, Smooth, Vascular/metabolism , Muscle, Smooth, Vascular/pathology , Animals , Myocytes, Smooth Muscle/metabolism , Myocytes, Smooth Muscle/pathology , Apoptosis Regulatory Proteins/metabolism , Apoptosis Regulatory Proteins/genetics , Phosphorylation , Adaptor Proteins, Signal Transducing/metabolism , Adaptor Proteins, Signal Transducing/genetics , Diabetic Angiopathies/metabolism , Diabetic Angiopathies/pathology , Diabetic Angiopathies/physiopathology , Diabetic Angiopathies/etiology , Diabetic Angiopathies/genetics , Male , Cells, Cultured , Mice, Knockout , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Experimental/pathology , Humans , Mice, Inbred C57BL , Glycation End Products, Advanced/metabolism
20.
Molecules ; 29(8)2024 Apr 12.
Article En | MEDLINE | ID: mdl-38675571

Phyllanthus emblica is a natural medicinal herb with diverse bioactivities. Certain extracts from this herb have been confirmed to possess anti-glycolipid metabolic disorder activity. To further develop its utility value and explore its potential in combating glycolipid metabolic disorders, we designed a series of experiments to investigate the structure, antioxidant activity, and anti-glycolipid metabolic disorder activity of Phyllanthus emblica polysaccharides. In this study, we extracted and purified polysaccharides from Phyllanthus emblica and thoroughly analyzed their structure using various techniques, including NMR, methylation analysis, and surface-enhanced Raman spectroscopy. We investigated the hypolipidemic and anti-glycolipid metabolism disorder activity of Phyllanthus emblica polysaccharides for the first time utilizing oleic acid (OA) and advanced glycation end products (AGEs) as inducers. Additionally, the antioxidant activity of Phyllanthus emblica polysaccharides was assessed in vitro. These findings lay the groundwork for future investigations into the potential application of Phyllanthus emblica polysaccharides as an intervention for preventing and treating diabetes.


Antioxidants , Phyllanthus emblica , Polysaccharides , Phyllanthus emblica/chemistry , Polysaccharides/pharmacology , Polysaccharides/chemistry , Polysaccharides/isolation & purification , Antioxidants/pharmacology , Antioxidants/chemistry , Antioxidants/isolation & purification , Glycolipids/chemistry , Glycolipids/pharmacology , Glycolipids/isolation & purification , Glycation End Products, Advanced/metabolism , Plant Extracts/pharmacology , Plant Extracts/chemistry , Animals , Oleic Acid/chemistry , Oleic Acid/pharmacology , Humans
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