Advanced glycation endproducts(AGEs) have been recognized as hazards in processed foods that can induce chronic diseases such as cardiovascular disease, diabetes, and diabetic nephropathy. In this study, we investigat...Advanced glycation endproducts(AGEs) have been recognized as hazards in processed foods that can induce chronic diseases such as cardiovascular disease, diabetes, and diabetic nephropathy. In this study, we investigated the AGEs contents of 35 types of industrial seafood products that are consumed frequently in eastern China. Total fluorescent AGEs level and Nε-carboxymethyl-lysine(CML) content were evaluated by fluorescence spectrophotometry and gas chromatography-mass spectrometry(GC-MS), respectively. The level of total fluorescent AGEs in seafood samples ranged from 39.37 to 1178.3 AU, and was higher in canned and packaged instant aquatic products that were processed at high temperatures. The CML content in seafood samples ranged from 44.8 to 439.1 mg per kg dried sample, and was higher in roasted seafood samples. The total fluorescent AGEs and CML content increased when seafood underwent high-temperature processing, but did not show an obvious correlation. The present study suggested that commonly consumed seafood contains different levels of AGEs, and the seafood processed at high temperatures always displays a high level of either AGEs or CML.展开更多
BACKGROUND In recent years,American Diabetes Association started to strongly advocate the Mediterranean diet(MD)over other diets in patients with diabetes mellitus(DM)because of its beneficial effects on glycemic cont...BACKGROUND In recent years,American Diabetes Association started to strongly advocate the Mediterranean diet(MD)over other diets in patients with diabetes mellitus(DM)because of its beneficial effects on glycemic control and cardiovascular(CV)risk factors.Tissue levels of advanced glycation endproducts(AGEs)emerged as an indicator of CV risk in DM.Skin biopsy being invasive,the use of AGE Reader has been shown to reflect tissue AGEs reliably.AIM To examine the association between adherence to MD and AGEs in patients with DM type II.METHODS This cross-sectional study was conducted on 273 patients with DM type II.A survey questionnaire was composed of 3 separate sections.The first part of the questionnaire included general data and the habits of the participants.The second part aimed to assess the basic parameters of participants’diseases and associated conditions.The third part of the questionnaire was the Croatian version of the 14-item MD service score(MDSS).AGEs levels and associated CV risk were measured using AGE Reader(DiagnOptics Technologies BV,Groningen,The Netherlands).RESULTS A total of 27(9.9%)patients fulfilled criteria for adherence to MD,with a median score of 8.0(6.0-10.0).Patients with none/limited CV risk had significantly higher percentage of MD adherence in comparison to patients with increased/definite CV risk(15.2%vs 6.9%,P=0.028),as well as better adherence to guidelines for nuts(23.2%vs 12.6%,P=0.023)and legumes(40.4%vs 25.9%,P=0.013)consumption.Higher number of patients with glycated hemoglobin(HbA1c)<7%adhered to MD when compared to patients with HbA1c>7%(14.9%vs 7.3%,P=0.045).Moreover,those patients followed the MDSS guidelines for eggs(33.0%vs 46.8%,P=0.025)and wine(15.6%vs 29.8%,P=0.006)consumption more frequently.MDSS score had significant positive correlation with disease duration(r=0.179,P=0.003)and negative correlation with body mass index(BMI)values(r=-0.159,P=0.008).In the multiple linear regression model,BMI(β±SE,-0.09±0.04,P=0.037)and disease duration(β±SE,0.07±0.02,P<0.001)remained significant independent correlates of the MDSS score.Patients with HbA1c>7%think that educational programs on nutrition would be useful for patients in significantly more cases than patients with HbA1c<7%(98.9%vs 92.6%,P=0.009).CONCLUSION Although adherence to MD was very low among people with diabetes,we demonstrated that adherence to MD is greater in patients with lower CV risk,longer disease duration,and well-controlled glycaemia.展开更多
Objective:To evaluate inhibitoy potential of seven Korean thistles against the advanced glyeatinn endproducts(AGE) formation as well as to identify responsible compounds from the most active species.Methods:We used an...Objective:To evaluate inhibitoy potential of seven Korean thistles against the advanced glyeatinn endproducts(AGE) formation as well as to identify responsible compounds from the most active species.Methods:We used an in vitro AGE inhibition assay to evaluate the antidiabetic complication potential of the methanol extracts of the selected Korean thistles.Results:Among the seven Korean thistles,the leaves of Cirsium maackii(C.maackii) exhibited the most significant inhibitory activity against AGE formation.By means of bioassay-directed fractionation,a lignan.chlorogenic acid and 14 flavonoids were isolated from the active ethyl acetate soluble fraction of a methanol extract from C.maackii leaves.Luteolin and its 5-O-glueoside have been previously isolated:however,a lignan and 13 known compounds were isolated for the first lime from C maackii leaves in this study.Most of the isolated compounds exhibited inhibitory activities against potential AGE formation.Among them,cernuoside was shown to be the most potent AGE inhibitor with an IC_(50) value of 21.21 μ mol/L.Most importantly,two major flavonoids,luteolin and ils 5-O-glucoside,also significantly inhibited AGE formation,with IC_(50) values of36.33 and 37.47 μmol/L,respectively.Structure activity relationship revealed that the presence of free 3'and 4' dihydroxyl group in flavonoids skeleton played an important role in AGE inhibition.Conclusions:These results indicate that C.maackii and C maackii-derived flavonoids might be explored further to develop therapeutic agents for the prevention of diabetic eoniplicalions due to their significant inhibitory activity against AGE formation.展开更多
BACKGROUND: Previous studies have demonstrated that reduced estrogen levels may accelerate the formation of advanced glycation endproducts (AGE) in brain tissue, raise the concentration of lipid peroxidation products ...BACKGROUND: Previous studies have demonstrated that reduced estrogen levels may accelerate the formation of advanced glycation endproducts (AGE) in brain tissue, raise the concentration of lipid peroxidation products in vivo, and speed up deterioration of learning and memory. A tonifying kidney recipe is hypothesized to improve the ability of learning and memory in ovariectomized rats by downregulating AGE and lipid peroxidation products. OBJECTIVE: To simulate a postmenopausal state, bilateral ovariectomy (OVX) was performed in rats, and the effects of tonifying kidney recipe (TKR) on AGE and lipid peroxidation in the rat cerebral cortex, hippocampus, and blood serum levels was measured. In addition, the effects on learning and memory were evaluated, and the effect of AGE -specific inhibitor aminoguanidine (AG) was compared with TKR. DESIGN, TIME AND SETTING: A randomized, in vivo, control experiment was performed at the scien- tific research center (Provincial Key Laboratory) in the Fourth Hospital of Hebei Medical University (Shijiazhuang, Hebei Province, China) from May 2005 to January 2007. MATERIALS: Forty healthy, adult, female, Sprague Dawley rats were used for this study. TKR was composed of prepared rehmannia rhizome, epimedium herb, desert-living cistanche, and Szechwan lovage rhizome, which were provided by Shijiazhuang Medical Materials Company (China). A TKR extraction was prepared for further use. AG was provided by Sigma (USA). Forty rats were randomly divided into four groups: sham, OVX, AG, and TKR, with 10 rats in each group. METHODS: The rat ovaries were resected in the OVX, AG, and TKR groups, whereas the same volume of fat was resected in the sham group. At four weeks after OVX, the AG group received 1% AG water solution by lavage; the TKR group was administrated by lavage once per day at a dose of 6.3 g (crude drug)/kg; OVX and sham groups received equal volumes of tap water. MAIN OUTCOME MEASURES: Learning and memory behavior of rats was tested in a Y-electric maze 16 weeks after the OVX procedure. The contents of advanced glycation endproducts in the rat cerebral cortex, hippocampus, serum, and urine were detected by competitive ELISA and spectrofluorophotometer. The con- tents of lipid peroxidation in rat serum, cerebral cortex, and hippocampus were assayed using a biochemical method. RESULTS: Compared with the sham group, serum content of advanced glycation endproducts in the OVX group was significantly increased, and lipid peroxidation content increased in cerebral cortex, hippocampus, and serum (t = 3.04-4.22, P < 0.05-0.01). Both AG and TKR decreased the amount of AGE in cerebral cor- tex and serum (t = 2.53, 3.64, P < 0.05, 0.01), increased AGE urine content (t = 3.25-4.87, P < 0.01), and decreased lipid peroxidation content in cerebral cortex, hippocampus, and serum (t = 2.80-3.70, P < 0.05-0.01). In comparison to the OVX and sham groups, the correct escape rate in the Y-electric maze was significantly increased (t = 3.46, 3.28, P < 0.01), and escape latency was significantly decreased (t=3.12, 2.48, P < 0.05) in the AG and TKR groups, which indicated that both AG and TKR improved learning and memory. The OVX group had a significantly lower correct escape compared with the sham group (t = 4.21, P < 0.01). CONCLUSION: The tonifying kidney recipe decreased deposition of advanced glycation endproducts and lipid peroxidation in ovariectomized rats, and concomitantly improved learning and memory. The effect of TKR was equal to that of AG.展开更多
Advanced glycation endproducts (AGEs) is implicated in the pathogenesis of diabetic complications. Inhibiting the formation of AGEs and interfering with AGEs-mediated inflammation are two practicable strategies for de...Advanced glycation endproducts (AGEs) is implicated in the pathogenesis of diabetic complications. Inhibiting the formation of AGEs and interfering with AGEs-mediated inflammation are two practicable strategies for developing a dietary adjuvant against diabetic complications. This study evaluated the protective capacities against diabetic complications of several spices based on their inhibition of the formation of AGEs in an in vitro BSA/glucose system and on the AGEs-induced production of proinflammatory cytokine in RAW 264.7 macrophages. Among the tested spices, cinnamon exhibited most strongly inhibited both the formation of AGEs and the AGEs-induced production of nitric oxide, interleukin-6 and tumor necrosis factor-α. Additionally, correlative results revealed that the capacity of spices to inhibit the formation of AGEs is attributable to phenolic compounds and, in contrast, the capacity to inhibit AGEs-induced inflammation is attributable to condensed tannin. This investigation demonstrates the potential of cinnamon to serve as a dietary adjuvant against diabetic complications.展开更多
The Advanced Glycation End Products(AGE)binding with its receptor can increase reactive oxygen species(ROS)generation through specific signaling mediators.The effect of superoxide(O2-)and O2-mediated ROS and reactive ...The Advanced Glycation End Products(AGE)binding with its receptor can increase reactive oxygen species(ROS)generation through specific signaling mediators.The effect of superoxide(O2-)and O2-mediated ROS and reactive nitrogen species depends on their concentration and location of formation.Nitric oxide(NO)has anti-inflammatory and anticoagulant properties and a vasodilation effect,but NO can be deactivated by reacting with O_(2)^(-).This reaction between NO and O2-produces the potent oxidant ONOO−.Therefore,ONOO-'s regulatory role in AGEs in diabetic cardiovascular complications must considered as a regulator of cardiovascular complications in diabetes.展开更多
Compelling shreds of evidence derived from both clinical and experimental research have demonstrated the crucial contribution of receptor for advanced glycation end products(RAGE)axis activation in the development of ...Compelling shreds of evidence derived from both clinical and experimental research have demonstrated the crucial contribution of receptor for advanced glycation end products(RAGE)axis activation in the development of neoplasms,including gastric cancer(GC).This new actor in tumor biology plays an important role in the onset of a crucial and long-lasting inflammatory milieu,not only by supporting phenotypic changes favoring growth and dissemination of tumor cells,but also by functioning as a pattern-recognition receptor in the inflammatory response to Helicobacter pylori infection.In the present review,we aim to highlight how the overexpression and activation of the RAGE axis contributes to the proliferation and survival of GC cells as and their acquisition of more invasive phenotypes that promote dissemination and metastasis.Finally,the contribution of some single nucleotide polymorphisms in the RAGE gene as susceptibility or poor prognosis factors is also discussed.展开更多
Investigation that protein oxidation to the formation of advanced glycation end products(AGEs)after chicken myofibrillar protein glycation is limited.Models of protein oxidation induced by different concentrations of ...Investigation that protein oxidation to the formation of advanced glycation end products(AGEs)after chicken myofibrillar protein glycation is limited.Models of protein oxidation induced by different concentrations of hydroxyl radicals(·OH)were developed after the chicken myofibrillar protein mild glycation(MPG).Results exhibited that levels of AGEs and surface hydrophobicity(H_(0))steadily increased with the a ddition of h ydrogen peroxide(H_(2)O_(2))concentration.However,levels of s ulfhydryl group,free amino group,and particle size gradually decreased with the H_(2)O_(2)concentration.The protein carbonyl value increased in H_(2)O_(2)concentration until 10 mmol/L.Pearson's correlation indicated that MPG structure modification(unfolding and degradation)induced by protein oxidation were significantly positively correlated with AGEs concentration(P<0.05).Finally,a mechanism was proposed to hypothesize t he effect of protein oxidation on the formation of AGEs under MPG conditions.展开更多
Obesity and type 2 diabetes mellitus(T2DM)are chronic pathologies with a high incidence worldwide.They share some pathological mechanisms,including hyperinsulinemia,the production and release of hormones,and hyperglyc...Obesity and type 2 diabetes mellitus(T2DM)are chronic pathologies with a high incidence worldwide.They share some pathological mechanisms,including hyperinsulinemia,the production and release of hormones,and hyperglycemia.The above,over time,affects other systems of the human body by causing tissue hypoxia,low-grade inflammation,and oxidative stress,which lay the pathophysiological groundwork for cancer.The leading causes of death globally are T2DM and cancer.Other main alterations of this pathological triad include the accumulation of advanced glycation end products and the release of endogenous alarmins due to cell death(i.e.,damage-associated molecular patterns)such as the intracellular proteins high-mobility group box protein 1 and protein S100 that bind to the receptor for advanced glycation products(RAGE)-a multiligand receptor involved in inflammatory and metabolic and neoplastic processes.This review analyzes the latest advanced reports on the role of RAGE in the development of obesity,T2DM,and cancer,with an aim to understand the intracellular signaling mechanisms linked with cancer initiation.This review also explores inflammation,oxidative stress,hypoxia,cellular senescence,RAGE ligands,tumor microenvironment changes,and the“cancer hallmarks”of the leading tumors associated with T2DM.The assimilation of this information could aid in the development of diagnostic and therapeutic approaches to lower the morbidity and mortality associated with these diseases.展开更多
Advanced glycation end products(AGEs)are a heterogeneous collection of compounds formed during industrial processing and home cooking through a sequence of nonenzymatic glycation reactions.The modern western diet is f...Advanced glycation end products(AGEs)are a heterogeneous collection of compounds formed during industrial processing and home cooking through a sequence of nonenzymatic glycation reactions.The modern western diet is full of heat-treated foods that contribute to AGE intake.Foods high in AGEs in the contemporary diet include processed cereal products.Due to industrialization and marketing strategies,restaurant meals are modified rather than being traditionally or conventionally cooked.Fried,grilled,baked,and boiled foods have the greatest AGE levels.Higher AGE-content foods include dry nuts,roasted walnuts,sunflower seeds,fried chicken,bacon,and beef.Animal proteins and processed plant foods contain furosine,acrylamide,heterocyclic amines,and 5-hydroxymethylfurfural.Furosine(2-furoil-methyl-lysine)is an amino acid found in cooked meat products and other processed foods.High concentrations of carboxymethyl-lysine,carboxyethyl-lysine,and methylglyoxal-O are found in heat-treated nonvegetarian foods,peanut butter,and cereal items.Increased plasma levels of AGEs,which are harmful chemicals that lead to age-related diseases and physiological aging,diabetes,and autoimmune/inflammatory rheumatic diseases such as systemic lupus erythematosus and rheumatoid arthritis.AGEs in the pathophysiology of metabolic diseases have been linked to individuals with diabetes mellitus who have peripheral nerves with high amounts of AGEs and diabetes has been linked to increased myelin glycation.Insulin resistance and hyperglycemia can impact numerous human tissues and organs,leading to long-term difficulties in a number of systems and organs,including the cardiovascular system.Plasma AGE levels are linked to all-cause mortality in individuals with diabetes who have fatal or nonfatal coronary artery disease,such as ventricular dysfunction.High levels of tissue AGEs are independently associated with cardiac systolic dysfunction in diabetic patients with heart failure compared with diabetic patients without heart failure.It is widely recognized that AGEs and oxidative stress play a key role in the cardiovascular complications of diabetes because they both influence and are impacted by oxidative stress.All chronic illnesses involve protein,lipid,or nucleic acid modifications including crosslinked and nondegradable aggregates known as AGEs.Endogenous AGE formation or dietary AGE uptake can result in additional protein modifications and stimulation of several inflammatory signaling pathways.Many of these systems,however,require additional explanation because they are not entirely obvious.This review summarizes the current evidence regarding dietary sources of AGEs and metabolism-related complications associated with AGEs.展开更多
The incidence of type 2 diabetes mellitus is growing in epidemic proportions and has become one of the most critical public health concerns.Cardiovascular complications associated with diabetes are the leading cause o...The incidence of type 2 diabetes mellitus is growing in epidemic proportions and has become one of the most critical public health concerns.Cardiovascular complications associated with diabetes are the leading cause of morbidity and mortality.The cardiovascular diseases that accompany diabetes include angina,myocardial infarction,stroke,peripheral artery disease,and congestive heart failure.Among the various risk factors generated secondary to hyperglycemic situations,advanced glycation end products(AGEs)are one of the important targets for future diagnosis and prevention of diabetes.In the last decade,AGEs have drawn a lot of attention due to their involvement in diabetic pathophysiology.AGEs can be derived exogenously and endogenously through various pathways.These are a nonhomogeneous,chemically diverse group of compounds formed nonenzymatically by condensation between carbonyl groups of reducing sugars and free amino groups of protein,lipids,and nucleic acid.AGEs mediate their pathological effects at the cellular and extracellular levels by multiple pathways.At the cellular level,they activate signaling cascades via the receptor for AGEs and initiate a complex series of intracellular signaling resulting in reactive oxygen species generation,inflammation,cellular proliferation,and fibrosis that may possibly exacerbate the damaging effects on cardiac functions in diabetics.AGEs also cause covalent modifications and cross-linking of serum and extracellular matrix proteins;altering their structure,stability,and functions.Early diagnosis of diabetes may prevent its progression to complications and decrease its associated comorbidities.In the present review,we recapitulate the role of AGEs as a crucial mediator of hyperglycemia-mediated detrimental effects in diabetes-associated complications.Furthermore,this review presents an overview of future perspectives for new therapeutic interventions to ameliorate cardiovascular complications in diabetes.展开更多
Objective:The main characteristics of diabetic nephropathy(DN)at the early stage are abnormal angiogenesis of glomerular endothelial cells(GECs)and macrophage infiltration.Galectin-3 plays a pivotal role in the pathog...Objective:The main characteristics of diabetic nephropathy(DN)at the early stage are abnormal angiogenesis of glomerular endothelial cells(GECs)and macrophage infiltration.Galectin-3 plays a pivotal role in the pathogenesis of DN via binding with its ligand,advanced glycation end products(AGEs).Catalpol,an iridoid glucoside extracted from Rehmannia glutinosa,has been found to ameliorate vascular inflammation,reduce endothelial permeability,and protect against endothelial damage in diabetic milieu.However,little is known about whether catalpol could exert an anti-angiogenesis and anti-inflammation effect induced by AGEs.Methods:Mouse GECs(mGECs)and RAW 264.7 macrophages were treated with different concentrations of AGEs(0,50,100,200 and 400μg/mL)for different time(0,6,12,24 and 48 h)to determine the optimal concentration of AGEs and treatment time.Cells were treated with catalpol(10μmol/L),GB1107(1μmol/L,galectin-3 inhibitor),PX-478(50μmol/L,HIF-1αinhibitor),adenovirus-green fluorescent protein(Ad-GFP)[3×10^(7)plaque-forming unit(PFU)/mL]or Ad-galectin-3-GFP(2×10^(8)PFU/mL),which was followed by incubation with 50μg/mL AGEs.The levels of galectin-3,vascular endothelial growth factor A(VEGFA)and pro-angiogenic factors angiopoietin-1(Ang-1),angiopoietin-2(Ang-2),tunica interna endothelial cell kinase-2(Tie-2)were detected by enzyme-linked immunosorbent assay(ELISA).Cell counting kit-8(CCK-8)assay was used to evaluate the proliferation of these cells.The expression levels of galectin-3,vascular endothelial growth factor receptor 1(VEGFR1),VEGFR2,and hypoxia-inducible factor-1α(HIF-1α)in mGECs and those of galectin-3 and HIF-1αin RAW 264.7 macrophages were detected by Western blotting and immunofluorescence(IF)staining.The rat DN model was established.Catalpol(100 mg/kg)or GB1107(10 mg/kg)was administered intragastrically once a day for 12 weeks.Ad-galectin-3-GFP(6×10^(7)PFU/mL,0.5 mL)or Ad-GFP(6×10^(6)PFU/mL,0.5 mL)was injected into the tail vein of rats 48 h before the sacrifice of the animals.The expression of galectin-3,VEGFR1,.VEGFR2,and HIF-1αin renal cortices was analyzed by Western blotting.The expression of galectin-3,F4/80(a macrophage biomarker),and CD34(an endothelium biomarker)in renal cortices was detected by IF staining,and collagen accumulation by Masson staining.Results:The expression levels of galectin-3 and VEGFA were significantly higher in mGECs and RAW 264.7 macrophages treated with 50μg/mL AGEs for 48 h than those in untreated cells.Catalpol and GB1107 could block the AGEs-induced proliferation of mGECs and RAW 264.7 macrophages.Over-expression of galectin-3 was found to reduce the inhibitory effect of catalpol on the proliferation of cells.Catalpol could significantly decrease the levels of Ang-1,Ang-2 and Tie-2 released by AGEs-treated mGECs,which could be reversed by over-expression of galectin-3.Catalpol could significantly inhibit AGEs-induced expression of galectin-3,HIF-1α,VEGFR1,and VEGFR2 in mGECs.The inhibitory effect of catalpol on galectin-3 in AGEs-treated mGECs was impaired by PX-478.Moreover,catalpol attenuated the AGEs-activated HIF-1α/galectin-3 pathway in RAW 264.7 macrophages,which was weakened by PX-478.Additionally,catalpol significantly inhibited the expression of galectin-3,macrophage infiltration,collagen accumulation,and angiogenesis in the kidney of diabetic rats.Over-expression of galectin-3 could antagonize these inhibitory effects of catalpol.Conclusion:Catalpol prevented the angiogenesis of mGECs and macrophage proliferation via inhibiting galectin-3.It could prevent the progression of diabetes-induced renal damage.展开更多
The placenta plays an important role in nutrient transport to maintain the growth and development of the embryo.Gestational diabetes mellitus(GDM),the most common complication during pregnancy,highly affects placental...The placenta plays an important role in nutrient transport to maintain the growth and development of the embryo.Gestational diabetes mellitus(GDM),the most common complication during pregnancy,highly affects placental function in late gestation.Advanced glycation end-products(AGEs),a complex and heterogeneous group of compounds engaged by the receptor for AGEs(RAGE),are closely associated with diabetes-related complications.In this study,AGEs induced a decrease in the expression of tight junction(TJ)proteins in BeWo cells and increased the paracellular permeability of trophoblast cells by regulating RAGE/NF-κB.Sprague-Dawley(SD)rats injected with 100 mg/kg AGEs-rat serum albumin(RSA)via the tail vein from embryo day 2 were set as the placental barrier dysfunction model group(n=10).The effect of AGEs on placental permeability was determined using the Evans-Blue dye extravasation method.The ultrastructure of the placenta samples was observed by transmission electron microscopy.The effects of AGEs on the placenta were confirmed by treating rats with RAGE antagonist FPS-ZM1 and soluble forms of RAGE(sRAGE).AGEs treatment increased placental permeability and disrupted the tight junctions in pregnant rat placenta,but has no effect on blood glucose.The expression of TJ-related proteins,including ZO-1,Occludin,and Claudin 5,were downregulated after AGEs treatment.Further,AGEs treatment increased the expression of RAGE and nuclear factor-κB in the placenta of rats and upregulated the levels of vascular endothelial growth factor.The effects of AGEs on the placenta were blocked by RAGE antagonist FPS-ZM1 and sRAGE.This study demonstrates the mechanism underlying AGEs-induced disturbance in placental function in pregnant rats and highlights the potential of AGEs in the treatment of GDM.展开更多
BACKGROUND Advanced glycation end products(AGEs)are diabetic metabolic toxic products that cannot be ignored.Nε-(carboxymethyl)lysine(CML),a component of AGEs,could increase macrophage lipid uptake,promote foam cell ...BACKGROUND Advanced glycation end products(AGEs)are diabetic metabolic toxic products that cannot be ignored.Nε-(carboxymethyl)lysine(CML),a component of AGEs,could increase macrophage lipid uptake,promote foam cell formation,and thereby accelerate atherosclerosis.The receptor for AGEs(RAGE)and cluster of differentiation 36(CD36)were the receptors of CML.However,it is still unknown whether RAGE and CD36 play key roles in CML-promoted lipid uptake.AIM Our study aimed to explore the role of RAGE and CD36 in CML-induced macrophage lipid uptake.METHODS In this study,we examined the effect of CML on lipid uptake by Raw264.7 macrophages.After adding 10 mmol/L CML,the lipid accumulation in macrophages was confirmed by oil red O staining.Expression changes of CD36 and RAGE were detected with immunoblotting and quantitative real-time polymerase chain reaction.The interaction between CML with CD36 and RAGE was verified by immunoprecipitation.We synthesized a novel N-succinimidyl-4-18Ffluorobenzoate-CML radioactive probe.Radioactive receptor-ligand binding assays were performed to test the binding affinity between CML with CD36 and RAGE.The effects of blocking CD36 or RAGE on CML-promoting lipid uptake were also detected.RESULTS The study revealed that CML significantly promoted lipid uptake by macrophages.Immunoprecipitation and radioactive receptor-ligand binding assays indicated that CML could specifically bind to both CD36 and RAGE.CML had a higher affinity for CD36 than RAGE.ARG82,ASN71,and THR70 were the potential interacting amino acids that CD36 binds to CML Anti-CD36 and anti-RAGE could block the uptake of CML by macrophages.The lipid uptake promotion effect of CML was significantly attenuated after blocking CD36 or RAGE.CONCLUSION Our results suggest that the binding of CML with CD36 and RAGE promotes macrophage lipid uptake.展开更多
AIM:To investigate changes in advanced glycation end products(AGEs) and their receptor(RAGE) expression in the gastrointestinal(GI) tract in type 2 diabetic rats.METHODS:Eight inherited type 2 diabetic rats GotoKakiza...AIM:To investigate changes in advanced glycation end products(AGEs) and their receptor(RAGE) expression in the gastrointestinal(GI) tract in type 2 diabetic rats.METHODS:Eight inherited type 2 diabetic rats GotoKakizak(GK) and ten age-matched normal rats were used in the study.From 18 wk of age,the body weight and blood glucose were measured every week and 2 wk respectively.When the rats reached 32 wk,twocentimeter segments of esophagus,duodenum,jejunum,ileum,and colon were excised and the wet weight was measured.The segments were fixed in 10% formalin,embedded in paraffin and five micron sections were cut.The layer thickness was measured in Hematoxylin and Eosin-stained slides.AGE [N epsilon-(carboxymethyl) lysine and N epsilon-(carboxyethyl)lysine] and RAGE were detected by immunohistochemistry staining and image analysis was done using Sigmascan Pro 4.0 image analysis software.RESULTS:The blood glucose concentration(mmol/L) at 18 wk age was highest in the GK group(8.88 ± 1.87 vs 6.90 ± 0.43,P < 0.001),a difference that continued to exist until the end of the experiment.The wet weight per unit length(mg/cm) increased in esophagus,jejunum and colon from the normal to the GK group(60.64 ± 9.96 vs 68.56 ± 11.69,P < 0.05 for esophagus; 87.01 ± 9.35 vs 105.29 ± 15.45,P < 0.01 for jejunum; 91.37 ± 7.25 vs 97.28 ± 10.90,P < 0.05 for colon).Histologically,the layer thickness of the GItract was higher for esophagus,jejunum and colon in the GK group [full thickness(μm):575.37 ± 69.22 vs 753.20 ± 150.41,P < 0.01 for esophagus; 813.51 ± 44.44 vs 884.81 ± 45.31,P < 0.05 for jejunum; 467.12 ± 65.92 vs 572.26 ± 93.60,P < 0.05 for colon].In esophagus,the AGE and RAGE mainly distributed in striated muscle cells and squamous epithelial cells.The AGE distribution was much stronger in the GK group compared to the normal group both in the striated muscle layer and mucosa layer(immuno-positive area/ total measuring area %:4.52 ± 0.89 vs 10.96 ± 1.34,P < 0.01 for muscle; 8.90 ± 2.62 vs 22.45 ± 1.26,P < 0.01 for mucosa).No visible difference was found for RAGE distribution between the two groups.In the intestine AGE and RAGE distributed in epithelial cells of villi and crypt.RAGE was also found in neurons in the myenteric and submucosal plexus.The intensity of AGE staining in mucosa of all segments and RAGE staining in neurons in all segments were strongest in the diabetes group.Significant difference for AGE was found in the epithelial cells of villi and crypt in duodenum(immunopositive area/total measuring area %:13.37 ± 3.51 vs 37.48 ± 8.43,P < 0.05 for villi; 0.38 ± 0.12 vs 1.87 ± 0.53,P < 0.05 for crypt) and for RAGE in neurons of all segments(e.g.,for jejunum:no staining neurons% 0 vs 0,mild 36.0 ± 5.2 vs 28.7 ± 3.5,moderate 53.2 ± 4.8 vs 55.8 ± 5.4,strong 10.7 ± 1.1 vs 15.4 ± 2.0,P < 0.05).In the colon,RAGE was primarily found in neurons in the myenteric and submucosal plexus.It was stronger in the diabetes group than in the normal group(no staining neurons% 6.2 ± 0.2 vs 0.3 ± 0.04,mild 14.9 ± 2.1 vs 17.6 ± 1.5,moderate 53.1 ± 4.6 vs 44.7 ± 4.4,strong 25.6 ± 18 vs 43.6 ± 4.0,P < 0.05).In the rectum,RAGE was primarily found in the mucosa epithelial cells.CONCLUSION:The AGE and RAGE expression was upregulated in the GI tract of GK diabetic rats and may contribute to GI dysfunction in type 2 diabetic patients.展开更多
Compelling evidence supports the crucial role of the receptor for advanced glycation end-products(RAGE)axis activation in many clinical entities.Since the beginning of the coronavirus disease 2019 pandemic,there is an...Compelling evidence supports the crucial role of the receptor for advanced glycation end-products(RAGE)axis activation in many clinical entities.Since the beginning of the coronavirus disease 2019 pandemic,there is an increasing concern about the risk and handling of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection in inflammatory gastrointestinal disorders,such as inflammatory bowel diseases(IBD).However,clinical data raised during pandemic suggests that IBD patients do not have an increased risk of contracting SARS-CoV-2 infection or develop a more severe course of infection.In the present review,we intend to highlight how two potentially important contributors to the inflammatory response to SARS-CoV-2 infection in IBD patients,the RAGE axis activation as well as the cross-talk with the renin-angiotensin system,are dampened by the high expression of soluble forms of both RAGE and the angiotensin-converting enzyme(ACE)2.The soluble form of RAGE functions as a decoy for its ligands,and soluble ACE2 seems to be an additionally attenuating contributor to RAGE axis activation,particularly by avoiding the transactivation of the RAGE axis that can be produced by the virus-mediated imbalance of the ACE/angiotensin II/angiotensin II receptor type 1 pathway.展开更多
AIM:To study the role of advanced glycation end products(AGE)and their specifi c receptor(RAGE)in the pathogenesis of liver fi brogenesis.METHODS:In vitro RAGE expression and extracellular matrix-related gene expressi...AIM:To study the role of advanced glycation end products(AGE)and their specifi c receptor(RAGE)in the pathogenesis of liver fi brogenesis.METHODS:In vitro RAGE expression and extracellular matrix-related gene expression in both rat and human hepatic stellate cells(HSC)were measured after stimulation with the two RAGE ligands,advanced glycation end product-bovine serum albumin(AGE-BSA)and Nε-(carboxymethyl)lysine(CML)-BSA,or with tumor necrosis factor-α(TNF-α).In vivo RAGE expression was examined in models of hepatic fi brosis induced by bile duct ligation or thioacetamide.The effects of AGE-BSA and CML-BSA on HSC proliferation,signal transduction and profi brogenic gene expression were studied in vitro.RESULTS:In hepatic fibrosis,RAGE expression was enhanced in activated HSC,and also in endothelial cells,inflammatory cells and activated bile duct epithelia.HSC expressed RAGE which was upregulated after stimulation with AGE-BSA,CML-BSA,and TNF-α.RAGE stimulation with AGE-BSA and CML-BSA did not alter HSC proliferation,apoptosis,fibrogenic signal transduction and fibrosis-or fibrolysis-related gene expression,except for marginal upregulation of procollagen α1(Ⅰ)mRNA by AGE-BSA.CONCLUSION:Despite upregulation of RAGE in activated HSC,RAGE stimulation by AGE does not alter their fibrogenic activation.Therefore,RAGE does not contribute directly to hepatic fibrogenesis.展开更多
AIM: To investigate the association of receptor for advanced glycation end products(RAGE) G82S and vascular endothelial growth factor(VEGF)-634 G/C gene polymorphisms with diabetic retinopathy(DR).METHODS: Our cross-s...AIM: To investigate the association of receptor for advanced glycation end products(RAGE) G82S and vascular endothelial growth factor(VEGF)-634 G/C gene polymorphisms with diabetic retinopathy(DR).METHODS: Our cross-sectional study included 61 diabetic patients, 12 of them had proliferative diabetic retinopathy(PDR), 15 had non proliferative diabetic retinopathy(NPDR), 34 had no diabetic retinopathy(NDR)and 61 healthy controls. Participants were tested for RAGE G82S and VEGF-634 G/C polymorphisms by polymerase chain reaction-restriction fragment length polymorphism.RESULTS: We found a significant association between VEGF-634 G/C polymorphism and PDR as PDR patients had increased incidence of VEGF-634 CC genotype compared to NDR patients [odds ratio for CC vs(GC +GG)=6.5, 95% CI=1.5-27.8, P =0.021]. Also VEGF-634 CC genotype and C allele were significantly higher in the PDR than in NPDR patients, which is a novel finding in our study(P =0.024, 0.009 respectively). The mean triglycerides level was significantly higher in diabetic patients with CC genotype(P =0.01) as compared to patients with other genotypes. All cases and control subjects were of the same heterozygous RAGE 82G/S genotype.CONCLUSION: Patients carrying VEGF-634 C polymorphism have a higher risk of PDR development,so VEGF-634 G/C polymorphism could be used as a predictive marker for PDR in diabetic patients. We could not find a significant association between RAGE G82S polymorphism and DR.展开更多
AIM:To investigate the level of mucosal expression and the involvement of the receptor for the advanced glycation end products(RAGE)in delayed apoptosis and tumor necrosis factor(TNF)-αproduction in Crohn’s disease(...AIM:To investigate the level of mucosal expression and the involvement of the receptor for the advanced glycation end products(RAGE)in delayed apoptosis and tumor necrosis factor(TNF)-αproduction in Crohn’s disease(CD).METHODS:Surgical and endoscopic specimens from both inflamed and non-inflamed areas of the ileum and/or colon were collected from 20 and 14 adult CD patients,respectively,and used for the assessment of RAGE expression by means of immunohistochemistry and western blotting analysis.Normal tissues from 21 control subjects were used for comparison.The same polyclonal anti-human RAGE antibody(R and D System)was used in all experimental conditions.RAGE staining was quantized by a score including both the amount of positive cells and intensity of immunoreactivity;cellular pattern was also described.The effects of RAGE blocking on apoptotic rate and TNF-αproduction were investigated on immune cells freshly isolated from CD mucosa and incubated both with and without the muramyl dipeptide used as antigenic stimulus.Statistical analysis was performed via the test for trend,with regression models to account for intra-patient correlations.A 2-sided P<0.05 was considered significant.RESULTS:In inflamed areas,RAGE expression in both the epithelial and lamina propria compartments was higher than control tissues(P=0.001 and 0.021,respectively),and a cluster of positive cells were usually found in proximity of ulcerative lesions.Similar results were obtained in the lamina propria compartment of non-inflamed areas(P=0.025).The pattern of staining was membranous and granular cytosolic at the epithelial level,while in the lamina propria it was diffuse cytosolic.When evaluating the amount of protein expression by immunoblotting,a significant increase of both surface area and band intensity(P<0.0001 for both)was observed in CD inflamed areas compared to control tissue,while in non-inflamed areas a significant increase was found only for band intensity(P<0.005).Moreover,a significantly lower expression in noninflamed areas in comparison with inflamed areas was found for both surface area and band intensity(P<0.0006 for both).Finally,RAGE blocking largely affects both the apoptotic rate of mucosal cells(towards an increase in both non-inflamed and inflamed areas of P<0.001 and<0.0001,respectively)and TNF-αsecretion(towards a decrease in both non-inflamed and inflamed areas of P<0.05 and<0.01,respectively),mainly in the presence of antigenic stimulation.CONCLUSION:RAGE is up-regulated in CD,especially in inflamed areas,and it appears to play a role in the mechanisms involved in chronic inflammation.展开更多
Objective To investigate the effects of hepatocyte growth factor(HGF)on vascular endothelial cells apoptosis induced by advanced glycation end products(AGEs)and its possible mechanism. Methods Human umbilical vein end...Objective To investigate the effects of hepatocyte growth factor(HGF)on vascular endothelial cells apoptosis induced by advanced glycation end products(AGEs)and its possible mechanism. Methods Human umbilical vein endothelial cells(HUVECs)were cultured in vitro and intervened by different concentrations of AGEs and HGF.The cell inhibitory rates of each group with different culture time(12, 24, 48, and 72 hours)were measured by methyl thiazolyl tetrazolium(MTT)assay. The early stage apoptosis was detected by flow cytometry with Annexin V-FITC/PI double staining, morphology of cell apoptosis was observed by hoechst 33258 fluorescence staining, and the expression of apoptosis-associated genes Bax and Bcl-2 were determined by Western blotting.The activity of caspase-3 was detected by enzyme-linked immunosorbent assay (ELISA).Results Morphological observation indicated that high concentration of AGEs induced characteristic apoptotic changes in HUVECs.Within a certain concentration range, HUVECs apoptosis inducing rates by AGEs were in both dose- and time-dependent manners.HGF significantly inhibited the apoptosis of HUVECs induced by AGEs (P< 0.05).AGEs significantly promoted expression of Bax protein, but not Bcl-2.Whereas HGF significantly promoted the expression of Bcl-2(P<0.01)and decreased the activity of caspase-3(P<0.05)without affecting Bax level.Conclusions AGEs can induce the apoptosis of endothelial cells in vitro.HGF may effectively attenuate AGEs-induced endothelial cells apoptosis through upregulating Bcl-2 gene expression and inhibiting caspase-3 activation.展开更多
基金supported by the National Natural Science Foundation of China (No.31371730)the National Science & Technology Pillar Program (2012BAD28B05)
文摘Advanced glycation endproducts(AGEs) have been recognized as hazards in processed foods that can induce chronic diseases such as cardiovascular disease, diabetes, and diabetic nephropathy. In this study, we investigated the AGEs contents of 35 types of industrial seafood products that are consumed frequently in eastern China. Total fluorescent AGEs level and Nε-carboxymethyl-lysine(CML) content were evaluated by fluorescence spectrophotometry and gas chromatography-mass spectrometry(GC-MS), respectively. The level of total fluorescent AGEs in seafood samples ranged from 39.37 to 1178.3 AU, and was higher in canned and packaged instant aquatic products that were processed at high temperatures. The CML content in seafood samples ranged from 44.8 to 439.1 mg per kg dried sample, and was higher in roasted seafood samples. The total fluorescent AGEs and CML content increased when seafood underwent high-temperature processing, but did not show an obvious correlation. The present study suggested that commonly consumed seafood contains different levels of AGEs, and the seafood processed at high temperatures always displays a high level of either AGEs or CML.
文摘BACKGROUND In recent years,American Diabetes Association started to strongly advocate the Mediterranean diet(MD)over other diets in patients with diabetes mellitus(DM)because of its beneficial effects on glycemic control and cardiovascular(CV)risk factors.Tissue levels of advanced glycation endproducts(AGEs)emerged as an indicator of CV risk in DM.Skin biopsy being invasive,the use of AGE Reader has been shown to reflect tissue AGEs reliably.AIM To examine the association between adherence to MD and AGEs in patients with DM type II.METHODS This cross-sectional study was conducted on 273 patients with DM type II.A survey questionnaire was composed of 3 separate sections.The first part of the questionnaire included general data and the habits of the participants.The second part aimed to assess the basic parameters of participants’diseases and associated conditions.The third part of the questionnaire was the Croatian version of the 14-item MD service score(MDSS).AGEs levels and associated CV risk were measured using AGE Reader(DiagnOptics Technologies BV,Groningen,The Netherlands).RESULTS A total of 27(9.9%)patients fulfilled criteria for adherence to MD,with a median score of 8.0(6.0-10.0).Patients with none/limited CV risk had significantly higher percentage of MD adherence in comparison to patients with increased/definite CV risk(15.2%vs 6.9%,P=0.028),as well as better adherence to guidelines for nuts(23.2%vs 12.6%,P=0.023)and legumes(40.4%vs 25.9%,P=0.013)consumption.Higher number of patients with glycated hemoglobin(HbA1c)<7%adhered to MD when compared to patients with HbA1c>7%(14.9%vs 7.3%,P=0.045).Moreover,those patients followed the MDSS guidelines for eggs(33.0%vs 46.8%,P=0.025)and wine(15.6%vs 29.8%,P=0.006)consumption more frequently.MDSS score had significant positive correlation with disease duration(r=0.179,P=0.003)and negative correlation with body mass index(BMI)values(r=-0.159,P=0.008).In the multiple linear regression model,BMI(β±SE,-0.09±0.04,P=0.037)and disease duration(β±SE,0.07±0.02,P<0.001)remained significant independent correlates of the MDSS score.Patients with HbA1c>7%think that educational programs on nutrition would be useful for patients in significantly more cases than patients with HbA1c<7%(98.9%vs 92.6%,P=0.009).CONCLUSION Although adherence to MD was very low among people with diabetes,we demonstrated that adherence to MD is greater in patients with lower CV risk,longer disease duration,and well-controlled glycaemia.
基金supported by the Pukyoug National University Research Fund in 2011(C-D-2011-0766)
文摘Objective:To evaluate inhibitoy potential of seven Korean thistles against the advanced glyeatinn endproducts(AGE) formation as well as to identify responsible compounds from the most active species.Methods:We used an in vitro AGE inhibition assay to evaluate the antidiabetic complication potential of the methanol extracts of the selected Korean thistles.Results:Among the seven Korean thistles,the leaves of Cirsium maackii(C.maackii) exhibited the most significant inhibitory activity against AGE formation.By means of bioassay-directed fractionation,a lignan.chlorogenic acid and 14 flavonoids were isolated from the active ethyl acetate soluble fraction of a methanol extract from C.maackii leaves.Luteolin and its 5-O-glueoside have been previously isolated:however,a lignan and 13 known compounds were isolated for the first lime from C maackii leaves in this study.Most of the isolated compounds exhibited inhibitory activities against potential AGE formation.Among them,cernuoside was shown to be the most potent AGE inhibitor with an IC_(50) value of 21.21 μ mol/L.Most importantly,two major flavonoids,luteolin and ils 5-O-glucoside,also significantly inhibited AGE formation,with IC_(50) values of36.33 and 37.47 μmol/L,respectively.Structure activity relationship revealed that the presence of free 3'and 4' dihydroxyl group in flavonoids skeleton played an important role in AGE inhibition.Conclusions:These results indicate that C.maackii and C maackii-derived flavonoids might be explored further to develop therapeutic agents for the prevention of diabetic eoniplicalions due to their significant inhibitory activity against AGE formation.
文摘BACKGROUND: Previous studies have demonstrated that reduced estrogen levels may accelerate the formation of advanced glycation endproducts (AGE) in brain tissue, raise the concentration of lipid peroxidation products in vivo, and speed up deterioration of learning and memory. A tonifying kidney recipe is hypothesized to improve the ability of learning and memory in ovariectomized rats by downregulating AGE and lipid peroxidation products. OBJECTIVE: To simulate a postmenopausal state, bilateral ovariectomy (OVX) was performed in rats, and the effects of tonifying kidney recipe (TKR) on AGE and lipid peroxidation in the rat cerebral cortex, hippocampus, and blood serum levels was measured. In addition, the effects on learning and memory were evaluated, and the effect of AGE -specific inhibitor aminoguanidine (AG) was compared with TKR. DESIGN, TIME AND SETTING: A randomized, in vivo, control experiment was performed at the scien- tific research center (Provincial Key Laboratory) in the Fourth Hospital of Hebei Medical University (Shijiazhuang, Hebei Province, China) from May 2005 to January 2007. MATERIALS: Forty healthy, adult, female, Sprague Dawley rats were used for this study. TKR was composed of prepared rehmannia rhizome, epimedium herb, desert-living cistanche, and Szechwan lovage rhizome, which were provided by Shijiazhuang Medical Materials Company (China). A TKR extraction was prepared for further use. AG was provided by Sigma (USA). Forty rats were randomly divided into four groups: sham, OVX, AG, and TKR, with 10 rats in each group. METHODS: The rat ovaries were resected in the OVX, AG, and TKR groups, whereas the same volume of fat was resected in the sham group. At four weeks after OVX, the AG group received 1% AG water solution by lavage; the TKR group was administrated by lavage once per day at a dose of 6.3 g (crude drug)/kg; OVX and sham groups received equal volumes of tap water. MAIN OUTCOME MEASURES: Learning and memory behavior of rats was tested in a Y-electric maze 16 weeks after the OVX procedure. The contents of advanced glycation endproducts in the rat cerebral cortex, hippocampus, serum, and urine were detected by competitive ELISA and spectrofluorophotometer. The con- tents of lipid peroxidation in rat serum, cerebral cortex, and hippocampus were assayed using a biochemical method. RESULTS: Compared with the sham group, serum content of advanced glycation endproducts in the OVX group was significantly increased, and lipid peroxidation content increased in cerebral cortex, hippocampus, and serum (t = 3.04-4.22, P < 0.05-0.01). Both AG and TKR decreased the amount of AGE in cerebral cor- tex and serum (t = 2.53, 3.64, P < 0.05, 0.01), increased AGE urine content (t = 3.25-4.87, P < 0.01), and decreased lipid peroxidation content in cerebral cortex, hippocampus, and serum (t = 2.80-3.70, P < 0.05-0.01). In comparison to the OVX and sham groups, the correct escape rate in the Y-electric maze was significantly increased (t = 3.46, 3.28, P < 0.01), and escape latency was significantly decreased (t=3.12, 2.48, P < 0.05) in the AG and TKR groups, which indicated that both AG and TKR improved learning and memory. The OVX group had a significantly lower correct escape compared with the sham group (t = 4.21, P < 0.01). CONCLUSION: The tonifying kidney recipe decreased deposition of advanced glycation endproducts and lipid peroxidation in ovariectomized rats, and concomitantly improved learning and memory. The effect of TKR was equal to that of AG.
文摘Advanced glycation endproducts (AGEs) is implicated in the pathogenesis of diabetic complications. Inhibiting the formation of AGEs and interfering with AGEs-mediated inflammation are two practicable strategies for developing a dietary adjuvant against diabetic complications. This study evaluated the protective capacities against diabetic complications of several spices based on their inhibition of the formation of AGEs in an in vitro BSA/glucose system and on the AGEs-induced production of proinflammatory cytokine in RAW 264.7 macrophages. Among the tested spices, cinnamon exhibited most strongly inhibited both the formation of AGEs and the AGEs-induced production of nitric oxide, interleukin-6 and tumor necrosis factor-α. Additionally, correlative results revealed that the capacity of spices to inhibit the formation of AGEs is attributable to phenolic compounds and, in contrast, the capacity to inhibit AGEs-induced inflammation is attributable to condensed tannin. This investigation demonstrates the potential of cinnamon to serve as a dietary adjuvant against diabetic complications.
文摘The Advanced Glycation End Products(AGE)binding with its receptor can increase reactive oxygen species(ROS)generation through specific signaling mediators.The effect of superoxide(O2-)and O2-mediated ROS and reactive nitrogen species depends on their concentration and location of formation.Nitric oxide(NO)has anti-inflammatory and anticoagulant properties and a vasodilation effect,but NO can be deactivated by reacting with O_(2)^(-).This reaction between NO and O2-produces the potent oxidant ONOO−.Therefore,ONOO-'s regulatory role in AGEs in diabetic cardiovascular complications must considered as a regulator of cardiovascular complications in diabetes.
文摘Compelling shreds of evidence derived from both clinical and experimental research have demonstrated the crucial contribution of receptor for advanced glycation end products(RAGE)axis activation in the development of neoplasms,including gastric cancer(GC).This new actor in tumor biology plays an important role in the onset of a crucial and long-lasting inflammatory milieu,not only by supporting phenotypic changes favoring growth and dissemination of tumor cells,but also by functioning as a pattern-recognition receptor in the inflammatory response to Helicobacter pylori infection.In the present review,we aim to highlight how the overexpression and activation of the RAGE axis contributes to the proliferation and survival of GC cells as and their acquisition of more invasive phenotypes that promote dissemination and metastasis.Finally,the contribution of some single nucleotide polymorphisms in the RAGE gene as susceptibility or poor prognosis factors is also discussed.
基金supported by National Key R&D Program of China(2021YFD2100104)griculture Research System of China(CARS-41-Z)+2 种基金Science and Technology Project of Nanjing City(202002040)Jiangsu Province Policy Guidance Program(BX2020008)Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX21_0579),China。
文摘Investigation that protein oxidation to the formation of advanced glycation end products(AGEs)after chicken myofibrillar protein glycation is limited.Models of protein oxidation induced by different concentrations of hydroxyl radicals(·OH)were developed after the chicken myofibrillar protein mild glycation(MPG).Results exhibited that levels of AGEs and surface hydrophobicity(H_(0))steadily increased with the a ddition of h ydrogen peroxide(H_(2)O_(2))concentration.However,levels of s ulfhydryl group,free amino group,and particle size gradually decreased with the H_(2)O_(2)concentration.The protein carbonyl value increased in H_(2)O_(2)concentration until 10 mmol/L.Pearson's correlation indicated that MPG structure modification(unfolding and degradation)induced by protein oxidation were significantly positively correlated with AGEs concentration(P<0.05).Finally,a mechanism was proposed to hypothesize t he effect of protein oxidation on the formation of AGEs under MPG conditions.
基金Supported by the Founding Proyectos de Impulso a la Investigación to Hernandez-Nazara ZH from Universidad de Guadalajara,Mexico,No.PIN 2020-I.
文摘Obesity and type 2 diabetes mellitus(T2DM)are chronic pathologies with a high incidence worldwide.They share some pathological mechanisms,including hyperinsulinemia,the production and release of hormones,and hyperglycemia.The above,over time,affects other systems of the human body by causing tissue hypoxia,low-grade inflammation,and oxidative stress,which lay the pathophysiological groundwork for cancer.The leading causes of death globally are T2DM and cancer.Other main alterations of this pathological triad include the accumulation of advanced glycation end products and the release of endogenous alarmins due to cell death(i.e.,damage-associated molecular patterns)such as the intracellular proteins high-mobility group box protein 1 and protein S100 that bind to the receptor for advanced glycation products(RAGE)-a multiligand receptor involved in inflammatory and metabolic and neoplastic processes.This review analyzes the latest advanced reports on the role of RAGE in the development of obesity,T2DM,and cancer,with an aim to understand the intracellular signaling mechanisms linked with cancer initiation.This review also explores inflammation,oxidative stress,hypoxia,cellular senescence,RAGE ligands,tumor microenvironment changes,and the“cancer hallmarks”of the leading tumors associated with T2DM.The assimilation of this information could aid in the development of diagnostic and therapeutic approaches to lower the morbidity and mortality associated with these diseases.
基金Supported by the Deputyship for Research and Innovation,Ministry of Education and Qassim University,Saudi Arabia(Project No.QUIF-2-2-1-27012).
文摘Advanced glycation end products(AGEs)are a heterogeneous collection of compounds formed during industrial processing and home cooking through a sequence of nonenzymatic glycation reactions.The modern western diet is full of heat-treated foods that contribute to AGE intake.Foods high in AGEs in the contemporary diet include processed cereal products.Due to industrialization and marketing strategies,restaurant meals are modified rather than being traditionally or conventionally cooked.Fried,grilled,baked,and boiled foods have the greatest AGE levels.Higher AGE-content foods include dry nuts,roasted walnuts,sunflower seeds,fried chicken,bacon,and beef.Animal proteins and processed plant foods contain furosine,acrylamide,heterocyclic amines,and 5-hydroxymethylfurfural.Furosine(2-furoil-methyl-lysine)is an amino acid found in cooked meat products and other processed foods.High concentrations of carboxymethyl-lysine,carboxyethyl-lysine,and methylglyoxal-O are found in heat-treated nonvegetarian foods,peanut butter,and cereal items.Increased plasma levels of AGEs,which are harmful chemicals that lead to age-related diseases and physiological aging,diabetes,and autoimmune/inflammatory rheumatic diseases such as systemic lupus erythematosus and rheumatoid arthritis.AGEs in the pathophysiology of metabolic diseases have been linked to individuals with diabetes mellitus who have peripheral nerves with high amounts of AGEs and diabetes has been linked to increased myelin glycation.Insulin resistance and hyperglycemia can impact numerous human tissues and organs,leading to long-term difficulties in a number of systems and organs,including the cardiovascular system.Plasma AGE levels are linked to all-cause mortality in individuals with diabetes who have fatal or nonfatal coronary artery disease,such as ventricular dysfunction.High levels of tissue AGEs are independently associated with cardiac systolic dysfunction in diabetic patients with heart failure compared with diabetic patients without heart failure.It is widely recognized that AGEs and oxidative stress play a key role in the cardiovascular complications of diabetes because they both influence and are impacted by oxidative stress.All chronic illnesses involve protein,lipid,or nucleic acid modifications including crosslinked and nondegradable aggregates known as AGEs.Endogenous AGE formation or dietary AGE uptake can result in additional protein modifications and stimulation of several inflammatory signaling pathways.Many of these systems,however,require additional explanation because they are not entirely obvious.This review summarizes the current evidence regarding dietary sources of AGEs and metabolism-related complications associated with AGEs.
文摘The incidence of type 2 diabetes mellitus is growing in epidemic proportions and has become one of the most critical public health concerns.Cardiovascular complications associated with diabetes are the leading cause of morbidity and mortality.The cardiovascular diseases that accompany diabetes include angina,myocardial infarction,stroke,peripheral artery disease,and congestive heart failure.Among the various risk factors generated secondary to hyperglycemic situations,advanced glycation end products(AGEs)are one of the important targets for future diagnosis and prevention of diabetes.In the last decade,AGEs have drawn a lot of attention due to their involvement in diabetic pathophysiology.AGEs can be derived exogenously and endogenously through various pathways.These are a nonhomogeneous,chemically diverse group of compounds formed nonenzymatically by condensation between carbonyl groups of reducing sugars and free amino groups of protein,lipids,and nucleic acid.AGEs mediate their pathological effects at the cellular and extracellular levels by multiple pathways.At the cellular level,they activate signaling cascades via the receptor for AGEs and initiate a complex series of intracellular signaling resulting in reactive oxygen species generation,inflammation,cellular proliferation,and fibrosis that may possibly exacerbate the damaging effects on cardiac functions in diabetics.AGEs also cause covalent modifications and cross-linking of serum and extracellular matrix proteins;altering their structure,stability,and functions.Early diagnosis of diabetes may prevent its progression to complications and decrease its associated comorbidities.In the present review,we recapitulate the role of AGEs as a crucial mediator of hyperglycemia-mediated detrimental effects in diabetes-associated complications.Furthermore,this review presents an overview of future perspectives for new therapeutic interventions to ameliorate cardiovascular complications in diabetes.
基金supported by grants from the National Natural Science Foundation of China(No.81374029,No.81073111,No.81874359)Natural Science Foundation of the Higher Education Institutions of Jiangsu Province(No.18KJD360002)+1 种基金a Project Funded by Jiangsu Agri-animal Husbandry Vocational College(No.NSF2021CB04)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)(No.JKLPSE201604).
文摘Objective:The main characteristics of diabetic nephropathy(DN)at the early stage are abnormal angiogenesis of glomerular endothelial cells(GECs)and macrophage infiltration.Galectin-3 plays a pivotal role in the pathogenesis of DN via binding with its ligand,advanced glycation end products(AGEs).Catalpol,an iridoid glucoside extracted from Rehmannia glutinosa,has been found to ameliorate vascular inflammation,reduce endothelial permeability,and protect against endothelial damage in diabetic milieu.However,little is known about whether catalpol could exert an anti-angiogenesis and anti-inflammation effect induced by AGEs.Methods:Mouse GECs(mGECs)and RAW 264.7 macrophages were treated with different concentrations of AGEs(0,50,100,200 and 400μg/mL)for different time(0,6,12,24 and 48 h)to determine the optimal concentration of AGEs and treatment time.Cells were treated with catalpol(10μmol/L),GB1107(1μmol/L,galectin-3 inhibitor),PX-478(50μmol/L,HIF-1αinhibitor),adenovirus-green fluorescent protein(Ad-GFP)[3×10^(7)plaque-forming unit(PFU)/mL]or Ad-galectin-3-GFP(2×10^(8)PFU/mL),which was followed by incubation with 50μg/mL AGEs.The levels of galectin-3,vascular endothelial growth factor A(VEGFA)and pro-angiogenic factors angiopoietin-1(Ang-1),angiopoietin-2(Ang-2),tunica interna endothelial cell kinase-2(Tie-2)were detected by enzyme-linked immunosorbent assay(ELISA).Cell counting kit-8(CCK-8)assay was used to evaluate the proliferation of these cells.The expression levels of galectin-3,vascular endothelial growth factor receptor 1(VEGFR1),VEGFR2,and hypoxia-inducible factor-1α(HIF-1α)in mGECs and those of galectin-3 and HIF-1αin RAW 264.7 macrophages were detected by Western blotting and immunofluorescence(IF)staining.The rat DN model was established.Catalpol(100 mg/kg)or GB1107(10 mg/kg)was administered intragastrically once a day for 12 weeks.Ad-galectin-3-GFP(6×10^(7)PFU/mL,0.5 mL)or Ad-GFP(6×10^(6)PFU/mL,0.5 mL)was injected into the tail vein of rats 48 h before the sacrifice of the animals.The expression of galectin-3,VEGFR1,.VEGFR2,and HIF-1αin renal cortices was analyzed by Western blotting.The expression of galectin-3,F4/80(a macrophage biomarker),and CD34(an endothelium biomarker)in renal cortices was detected by IF staining,and collagen accumulation by Masson staining.Results:The expression levels of galectin-3 and VEGFA were significantly higher in mGECs and RAW 264.7 macrophages treated with 50μg/mL AGEs for 48 h than those in untreated cells.Catalpol and GB1107 could block the AGEs-induced proliferation of mGECs and RAW 264.7 macrophages.Over-expression of galectin-3 was found to reduce the inhibitory effect of catalpol on the proliferation of cells.Catalpol could significantly decrease the levels of Ang-1,Ang-2 and Tie-2 released by AGEs-treated mGECs,which could be reversed by over-expression of galectin-3.Catalpol could significantly inhibit AGEs-induced expression of galectin-3,HIF-1α,VEGFR1,and VEGFR2 in mGECs.The inhibitory effect of catalpol on galectin-3 in AGEs-treated mGECs was impaired by PX-478.Moreover,catalpol attenuated the AGEs-activated HIF-1α/galectin-3 pathway in RAW 264.7 macrophages,which was weakened by PX-478.Additionally,catalpol significantly inhibited the expression of galectin-3,macrophage infiltration,collagen accumulation,and angiogenesis in the kidney of diabetic rats.Over-expression of galectin-3 could antagonize these inhibitory effects of catalpol.Conclusion:Catalpol prevented the angiogenesis of mGECs and macrophage proliferation via inhibiting galectin-3.It could prevent the progression of diabetes-induced renal damage.
基金This work was financially supported by The Jiangsu Provincial Maternal and Child Health Key Talents Project(F202042).
文摘The placenta plays an important role in nutrient transport to maintain the growth and development of the embryo.Gestational diabetes mellitus(GDM),the most common complication during pregnancy,highly affects placental function in late gestation.Advanced glycation end-products(AGEs),a complex and heterogeneous group of compounds engaged by the receptor for AGEs(RAGE),are closely associated with diabetes-related complications.In this study,AGEs induced a decrease in the expression of tight junction(TJ)proteins in BeWo cells and increased the paracellular permeability of trophoblast cells by regulating RAGE/NF-κB.Sprague-Dawley(SD)rats injected with 100 mg/kg AGEs-rat serum albumin(RSA)via the tail vein from embryo day 2 were set as the placental barrier dysfunction model group(n=10).The effect of AGEs on placental permeability was determined using the Evans-Blue dye extravasation method.The ultrastructure of the placenta samples was observed by transmission electron microscopy.The effects of AGEs on the placenta were confirmed by treating rats with RAGE antagonist FPS-ZM1 and soluble forms of RAGE(sRAGE).AGEs treatment increased placental permeability and disrupted the tight junctions in pregnant rat placenta,but has no effect on blood glucose.The expression of TJ-related proteins,including ZO-1,Occludin,and Claudin 5,were downregulated after AGEs treatment.Further,AGEs treatment increased the expression of RAGE and nuclear factor-κB in the placenta of rats and upregulated the levels of vascular endothelial growth factor.The effects of AGEs on the placenta were blocked by RAGE antagonist FPS-ZM1 and sRAGE.This study demonstrates the mechanism underlying AGEs-induced disturbance in placental function in pregnant rats and highlights the potential of AGEs in the treatment of GDM.
基金Supported by The National Natural Science Foundation of China,No.82070455Natural Science Foundation of Jiangsu Province,No.BK20201225Medical Innovation Team Project of Jiangsu Province,No.CXTDA2017010。
文摘BACKGROUND Advanced glycation end products(AGEs)are diabetic metabolic toxic products that cannot be ignored.Nε-(carboxymethyl)lysine(CML),a component of AGEs,could increase macrophage lipid uptake,promote foam cell formation,and thereby accelerate atherosclerosis.The receptor for AGEs(RAGE)and cluster of differentiation 36(CD36)were the receptors of CML.However,it is still unknown whether RAGE and CD36 play key roles in CML-promoted lipid uptake.AIM Our study aimed to explore the role of RAGE and CD36 in CML-induced macrophage lipid uptake.METHODS In this study,we examined the effect of CML on lipid uptake by Raw264.7 macrophages.After adding 10 mmol/L CML,the lipid accumulation in macrophages was confirmed by oil red O staining.Expression changes of CD36 and RAGE were detected with immunoblotting and quantitative real-time polymerase chain reaction.The interaction between CML with CD36 and RAGE was verified by immunoprecipitation.We synthesized a novel N-succinimidyl-4-18Ffluorobenzoate-CML radioactive probe.Radioactive receptor-ligand binding assays were performed to test the binding affinity between CML with CD36 and RAGE.The effects of blocking CD36 or RAGE on CML-promoting lipid uptake were also detected.RESULTS The study revealed that CML significantly promoted lipid uptake by macrophages.Immunoprecipitation and radioactive receptor-ligand binding assays indicated that CML could specifically bind to both CD36 and RAGE.CML had a higher affinity for CD36 than RAGE.ARG82,ASN71,and THR70 were the potential interacting amino acids that CD36 binds to CML Anti-CD36 and anti-RAGE could block the uptake of CML by macrophages.The lipid uptake promotion effect of CML was significantly attenuated after blocking CD36 or RAGE.CONCLUSION Our results suggest that the binding of CML with CD36 and RAGE promotes macrophage lipid uptake.
文摘AIM:To investigate changes in advanced glycation end products(AGEs) and their receptor(RAGE) expression in the gastrointestinal(GI) tract in type 2 diabetic rats.METHODS:Eight inherited type 2 diabetic rats GotoKakizak(GK) and ten age-matched normal rats were used in the study.From 18 wk of age,the body weight and blood glucose were measured every week and 2 wk respectively.When the rats reached 32 wk,twocentimeter segments of esophagus,duodenum,jejunum,ileum,and colon were excised and the wet weight was measured.The segments were fixed in 10% formalin,embedded in paraffin and five micron sections were cut.The layer thickness was measured in Hematoxylin and Eosin-stained slides.AGE [N epsilon-(carboxymethyl) lysine and N epsilon-(carboxyethyl)lysine] and RAGE were detected by immunohistochemistry staining and image analysis was done using Sigmascan Pro 4.0 image analysis software.RESULTS:The blood glucose concentration(mmol/L) at 18 wk age was highest in the GK group(8.88 ± 1.87 vs 6.90 ± 0.43,P < 0.001),a difference that continued to exist until the end of the experiment.The wet weight per unit length(mg/cm) increased in esophagus,jejunum and colon from the normal to the GK group(60.64 ± 9.96 vs 68.56 ± 11.69,P < 0.05 for esophagus; 87.01 ± 9.35 vs 105.29 ± 15.45,P < 0.01 for jejunum; 91.37 ± 7.25 vs 97.28 ± 10.90,P < 0.05 for colon).Histologically,the layer thickness of the GItract was higher for esophagus,jejunum and colon in the GK group [full thickness(μm):575.37 ± 69.22 vs 753.20 ± 150.41,P < 0.01 for esophagus; 813.51 ± 44.44 vs 884.81 ± 45.31,P < 0.05 for jejunum; 467.12 ± 65.92 vs 572.26 ± 93.60,P < 0.05 for colon].In esophagus,the AGE and RAGE mainly distributed in striated muscle cells and squamous epithelial cells.The AGE distribution was much stronger in the GK group compared to the normal group both in the striated muscle layer and mucosa layer(immuno-positive area/ total measuring area %:4.52 ± 0.89 vs 10.96 ± 1.34,P < 0.01 for muscle; 8.90 ± 2.62 vs 22.45 ± 1.26,P < 0.01 for mucosa).No visible difference was found for RAGE distribution between the two groups.In the intestine AGE and RAGE distributed in epithelial cells of villi and crypt.RAGE was also found in neurons in the myenteric and submucosal plexus.The intensity of AGE staining in mucosa of all segments and RAGE staining in neurons in all segments were strongest in the diabetes group.Significant difference for AGE was found in the epithelial cells of villi and crypt in duodenum(immunopositive area/total measuring area %:13.37 ± 3.51 vs 37.48 ± 8.43,P < 0.05 for villi; 0.38 ± 0.12 vs 1.87 ± 0.53,P < 0.05 for crypt) and for RAGE in neurons of all segments(e.g.,for jejunum:no staining neurons% 0 vs 0,mild 36.0 ± 5.2 vs 28.7 ± 3.5,moderate 53.2 ± 4.8 vs 55.8 ± 5.4,strong 10.7 ± 1.1 vs 15.4 ± 2.0,P < 0.05).In the colon,RAGE was primarily found in neurons in the myenteric and submucosal plexus.It was stronger in the diabetes group than in the normal group(no staining neurons% 6.2 ± 0.2 vs 0.3 ± 0.04,mild 14.9 ± 2.1 vs 17.6 ± 1.5,moderate 53.1 ± 4.6 vs 44.7 ± 4.4,strong 25.6 ± 18 vs 43.6 ± 4.0,P < 0.05).In the rectum,RAGE was primarily found in the mucosa epithelial cells.CONCLUSION:The AGE and RAGE expression was upregulated in the GI tract of GK diabetic rats and may contribute to GI dysfunction in type 2 diabetic patients.
文摘Compelling evidence supports the crucial role of the receptor for advanced glycation end-products(RAGE)axis activation in many clinical entities.Since the beginning of the coronavirus disease 2019 pandemic,there is an increasing concern about the risk and handling of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection in inflammatory gastrointestinal disorders,such as inflammatory bowel diseases(IBD).However,clinical data raised during pandemic suggests that IBD patients do not have an increased risk of contracting SARS-CoV-2 infection or develop a more severe course of infection.In the present review,we intend to highlight how two potentially important contributors to the inflammatory response to SARS-CoV-2 infection in IBD patients,the RAGE axis activation as well as the cross-talk with the renin-angiotensin system,are dampened by the high expression of soluble forms of both RAGE and the angiotensin-converting enzyme(ACE)2.The soluble form of RAGE functions as a decoy for its ligands,and soluble ACE2 seems to be an additionally attenuating contributor to RAGE axis activation,particularly by avoiding the transactivation of the RAGE axis that can be produced by the virus-mediated imbalance of the ACE/angiotensin II/angiotensin II receptor type 1 pathway.
基金Supported by Grants from the Interdisciplinary Center for Clinical Research(IZKF,Project B39)the Johannes and Frieda Marohn Foundation of the University of Erlangen-Nuremberg,Germany
文摘AIM:To study the role of advanced glycation end products(AGE)and their specifi c receptor(RAGE)in the pathogenesis of liver fi brogenesis.METHODS:In vitro RAGE expression and extracellular matrix-related gene expression in both rat and human hepatic stellate cells(HSC)were measured after stimulation with the two RAGE ligands,advanced glycation end product-bovine serum albumin(AGE-BSA)and Nε-(carboxymethyl)lysine(CML)-BSA,or with tumor necrosis factor-α(TNF-α).In vivo RAGE expression was examined in models of hepatic fi brosis induced by bile duct ligation or thioacetamide.The effects of AGE-BSA and CML-BSA on HSC proliferation,signal transduction and profi brogenic gene expression were studied in vitro.RESULTS:In hepatic fibrosis,RAGE expression was enhanced in activated HSC,and also in endothelial cells,inflammatory cells and activated bile duct epithelia.HSC expressed RAGE which was upregulated after stimulation with AGE-BSA,CML-BSA,and TNF-α.RAGE stimulation with AGE-BSA and CML-BSA did not alter HSC proliferation,apoptosis,fibrogenic signal transduction and fibrosis-or fibrolysis-related gene expression,except for marginal upregulation of procollagen α1(Ⅰ)mRNA by AGE-BSA.CONCLUSION:Despite upregulation of RAGE in activated HSC,RAGE stimulation by AGE does not alter their fibrogenic activation.Therefore,RAGE does not contribute directly to hepatic fibrogenesis.
文摘AIM: To investigate the association of receptor for advanced glycation end products(RAGE) G82S and vascular endothelial growth factor(VEGF)-634 G/C gene polymorphisms with diabetic retinopathy(DR).METHODS: Our cross-sectional study included 61 diabetic patients, 12 of them had proliferative diabetic retinopathy(PDR), 15 had non proliferative diabetic retinopathy(NPDR), 34 had no diabetic retinopathy(NDR)and 61 healthy controls. Participants were tested for RAGE G82S and VEGF-634 G/C polymorphisms by polymerase chain reaction-restriction fragment length polymorphism.RESULTS: We found a significant association between VEGF-634 G/C polymorphism and PDR as PDR patients had increased incidence of VEGF-634 CC genotype compared to NDR patients [odds ratio for CC vs(GC +GG)=6.5, 95% CI=1.5-27.8, P =0.021]. Also VEGF-634 CC genotype and C allele were significantly higher in the PDR than in NPDR patients, which is a novel finding in our study(P =0.024, 0.009 respectively). The mean triglycerides level was significantly higher in diabetic patients with CC genotype(P =0.01) as compared to patients with other genotypes. All cases and control subjects were of the same heterozygous RAGE 82G/S genotype.CONCLUSION: Patients carrying VEGF-634 C polymorphism have a higher risk of PDR development,so VEGF-634 G/C polymorphism could be used as a predictive marker for PDR in diabetic patients. We could not find a significant association between RAGE G82S polymorphism and DR.
基金Supported by A grant from Direzione ScientificaFondazione IRCCS Policlinico San Matteo-Progetto di Ricerca Correntecode 08061307/11
文摘AIM:To investigate the level of mucosal expression and the involvement of the receptor for the advanced glycation end products(RAGE)in delayed apoptosis and tumor necrosis factor(TNF)-αproduction in Crohn’s disease(CD).METHODS:Surgical and endoscopic specimens from both inflamed and non-inflamed areas of the ileum and/or colon were collected from 20 and 14 adult CD patients,respectively,and used for the assessment of RAGE expression by means of immunohistochemistry and western blotting analysis.Normal tissues from 21 control subjects were used for comparison.The same polyclonal anti-human RAGE antibody(R and D System)was used in all experimental conditions.RAGE staining was quantized by a score including both the amount of positive cells and intensity of immunoreactivity;cellular pattern was also described.The effects of RAGE blocking on apoptotic rate and TNF-αproduction were investigated on immune cells freshly isolated from CD mucosa and incubated both with and without the muramyl dipeptide used as antigenic stimulus.Statistical analysis was performed via the test for trend,with regression models to account for intra-patient correlations.A 2-sided P<0.05 was considered significant.RESULTS:In inflamed areas,RAGE expression in both the epithelial and lamina propria compartments was higher than control tissues(P=0.001 and 0.021,respectively),and a cluster of positive cells were usually found in proximity of ulcerative lesions.Similar results were obtained in the lamina propria compartment of non-inflamed areas(P=0.025).The pattern of staining was membranous and granular cytosolic at the epithelial level,while in the lamina propria it was diffuse cytosolic.When evaluating the amount of protein expression by immunoblotting,a significant increase of both surface area and band intensity(P<0.0001 for both)was observed in CD inflamed areas compared to control tissue,while in non-inflamed areas a significant increase was found only for band intensity(P<0.005).Moreover,a significantly lower expression in noninflamed areas in comparison with inflamed areas was found for both surface area and band intensity(P<0.0006 for both).Finally,RAGE blocking largely affects both the apoptotic rate of mucosal cells(towards an increase in both non-inflamed and inflamed areas of P<0.001 and<0.0001,respectively)and TNF-αsecretion(towards a decrease in both non-inflamed and inflamed areas of P<0.05 and<0.01,respectively),mainly in the presence of antigenic stimulation.CONCLUSION:RAGE is up-regulated in CD,especially in inflamed areas,and it appears to play a role in the mechanisms involved in chronic inflammation.
文摘Objective To investigate the effects of hepatocyte growth factor(HGF)on vascular endothelial cells apoptosis induced by advanced glycation end products(AGEs)and its possible mechanism. Methods Human umbilical vein endothelial cells(HUVECs)were cultured in vitro and intervened by different concentrations of AGEs and HGF.The cell inhibitory rates of each group with different culture time(12, 24, 48, and 72 hours)were measured by methyl thiazolyl tetrazolium(MTT)assay. The early stage apoptosis was detected by flow cytometry with Annexin V-FITC/PI double staining, morphology of cell apoptosis was observed by hoechst 33258 fluorescence staining, and the expression of apoptosis-associated genes Bax and Bcl-2 were determined by Western blotting.The activity of caspase-3 was detected by enzyme-linked immunosorbent assay (ELISA).Results Morphological observation indicated that high concentration of AGEs induced characteristic apoptotic changes in HUVECs.Within a certain concentration range, HUVECs apoptosis inducing rates by AGEs were in both dose- and time-dependent manners.HGF significantly inhibited the apoptosis of HUVECs induced by AGEs (P< 0.05).AGEs significantly promoted expression of Bax protein, but not Bcl-2.Whereas HGF significantly promoted the expression of Bcl-2(P<0.01)and decreased the activity of caspase-3(P<0.05)without affecting Bax level.Conclusions AGEs can induce the apoptosis of endothelial cells in vitro.HGF may effectively attenuate AGEs-induced endothelial cells apoptosis through upregulating Bcl-2 gene expression and inhibiting caspase-3 activation.
